1. Patent Search
  2. Details

PROTECTIVE HYDROPHOBIC MATERIALS FOR SECONDARY BATTERIES

20230387390 · 2023-11-30

    Inventors

    Cpc classification

    International classification

    Abstract

    This disclosure is generally directed to coating materials for cathode active materials useful in lithium ion batteries (LIBs). The coatings include a metal fluoride (MF.sub.x), a lithium metal fluoride (Li-M-F), or both, which are stable with cathode materials such as LiFePO.sub.4, and helpful in protecting against battery degradation materials (i.e., HF, LiF, PF.sub.5.sup.−, and LiOH).

    Claims

    1. A cathode composition comprising a particulate bulk cathode active material comprising a coating on a surface of the particulate bulk cathode active material, the coating comprising a metal fluoride, a lithium metal fluoride, or both a metal fluoride and a lithium metal fluoride; wherein the coating comprises a greater LiFePO.sub.4 stability score when normalized to that of AlF.sub.3 at 100%.

    2. The cathode composition of claim 1, wherein the coating comprises a metal fluoride and further comprises a greater LiOH score when normalized to that of FeF.sub.2 at 100%.

    3. The cathode composition of claim 1, wherein the coating comprises a lithium metal fluoride and further comprises: a greater HF score when normalized to that of Li.sub.2NiF.sub.4 at 100%; or a greater PF.sub.5.sup.− score when normalized to that of Li.sub.2NiF.sub.4 at 100%; or both a greater HF score when normalized to that of Li.sub.2NiF.sub.4 at 100% and a greater PF.sub.5.sup.− score when normalized to that of Li.sub.2NiF.sub.4 at 100%.

    4. The cathode composition of claim 1, wherein the coating comprises SrF.sub.2, LaF.sub.3, NdF.sub.3, or a mixture of any two or more thereof.

    5. The cathode composition of claim 1, wherein the coating comprises MgF.sub.2, MnF.sub.2, FeF.sub.2, MoF.sub.3, or a mixture of any two or more thereof.

    6. The cathode composition of claim 1, wherein the coating comprises Li.sub.3AlF.sub.6, Li.sub.3ScF.sub.6, Li.sub.2NiF.sub.4, LiBiF.sub.4, Li.sub.3FeF.sub.6, or a mixture of any two or more thereof.

    7. The cathode composition of claim 1, wherein the coating comprises LiYF.sub.4, LiInF.sub.4, Li.sub.2SnF.sub.6, LiCeF.sub.5, or a mixture of any two or more thereof.

    8. The cathode composition of claim 1, wherein cathode composition comprises about 0.1 wt % to about 5 wt % of the metal fluoride, the lithium metal fluoride, or both the metal fluoride and the lithium metal fluoride.

    9. The cathode composition of claim 1, wherein the coating comprises an average thickness on the bulk cathode active material of about 5 nm to about 2 μm.

    10. The cathode composition of claim 1, wherein the coating comprises a first coating material on the surface of the particulate bulk cathode active material and a second coating material overcoating the first coating material, wherein: the first coating material, the second coating material, or both the first coating material and second coating material comprise the metal fluoride, the lithium metal fluoride, or both the metal fluoride and a lithium metal fluoride.

    11. The cathode composition of claim 10, wherein the first coating material comprises a carbon coating, and the second coating material comprises MgF.sub.2, MnF.sub.2, FeF.sub.2, SrF.sub.2, MoF.sub.3, LaF.sub.3, NdF.sub.3, Li.sub.3AlF.sub.6, Li.sub.3ScF.sub.6, Li.sub.2NiF.sub.4, LiYF.sub.4, LiInF.sub.4, Li.sub.2SnF.sub.6, LiCeF.sub.5, LiBiF.sub.4, Li.sub.3FeF.sub.6, or a mixture of any two or more thereof.

    12. The cathode composition of claim 10, wherein the first coating material, the second coating material, or both the first coating material and second coating material comprise a carbon coating.

    13. The cathode composition of claim 10, wherein the first coating material comprises AlF.sub.3, and the second coating material comprises MgF.sub.2, MnF.sub.2, FeF.sub.2, SrF.sub.2, MoF.sub.3, LaF.sub.3, NdF.sub.3, Li.sub.3AlF.sub.6, Li.sub.3ScF.sub.6, Li.sub.2NiF.sub.4, LiYF.sub.4, LiInF.sub.4, Li.sub.2SnF.sub.6, LiCeF.sub.5, LiBiF.sub.4, Li.sub.3FeF.sub.6, or a mixture of any two or more thereof.

    14. The cathode composition of claim 1, wherein the particulate bulk cathode active material comprises one or more olivine-type cathode active materials, a nickel-rich cathode active material, or one or more olivine-type cathode active materials and a nickel-rich cathode active material.

    15. The cathode composition of claim 1, wherein the particulate bulk cathode active material comprises an olivine-type LiFePO.sub.4, an olivine-type LiMn.sub.1-xFePO.sub.4 where 0<x<1, or both an olivine-type LiFePO.sub.4 and an olivine-type LiMn.sub.1-xFePO.sub.4 where 0<x<1.

    16. The cathode composition of claim 1, wherein the particulate bulk cathode active material is a lithium nickel-manganese-cobalt oxide (“NMC”) cathode material.

    17. The cathode composition of claim 1, wherein the particulate bulk cathode active material is LiCOO.sub.2, Li(Ni.sub.aMn.sub.bCo.sub.c)O.sub.2, Li.sub.1+x(Ni.sub.aMn.sub.bCo.sub.c).sub.1-xO.sub.2, or Li(Mn.sub.αNi.sub.β).sub.2O.sub.4, wherein 0<a<1, 0<b<1, 0<c<1, a+b+c=1, 0<α<1, 0<β<1, and α+β=1.

    18. A lithium ion battery comprising: a cathode comprising a particulate bulk cathode active material and optionally a current collector; and optionally a housing; wherein: one or more of the particulate bulk cathode active material, the current collector, or an inner surface of the housing is at least partially coated with a metal fluoride, a lithium metal fluoride, or a combination of a metal fluoride and a lithium metal fluoride, wherein the coating comprises a greater LiFePO.sub.4 stability score when normalized to that of AlF.sub.3 at 100%.

    19. The lithium ion battery of claim 15, wherein the coating comprises MgF.sub.2, MnF.sub.2, FeF.sub.2, SrF.sub.2, MoF.sub.3, LaF.sub.3, NdF.sub.3, Li.sub.3AlF.sub.6, Li.sub.3ScF.sub.6, Li.sub.2NiF.sub.4, LiYF.sub.4, LiInF.sub.4, Li.sub.2SnF.sub.6, LiCeF.sub.5, LiBiF.sub.4, Li.sub.3FeF.sub.6, or a mixture of any two or more thereof.

    20. A process of manufacturing a cathode for a lithium ion battery, the process comprising: mixing a particulate bulk cathode active material comprising a surface coating with conductive carbon and a binder in a solvent to form a slurry, the surface coating comprising a metal fluoride, a lithium metal fluoride, or both a metal fluoride and a lithium metal fluoride; coating the slurry onto a cathode current collector, and removing the solvent; wherein: the surface coating comprises a greater LiFePO.sub.4 stability score when normalized to that of AlF.sub.3 at 100%.

    Description

    BRIEF DESCRIPTION OF THE DRAWINGS

    [0004] FIG. 1 shows three different D/G ratio for Raman measurements, where lower D/G ratio is desired to reduce amount of carbon derivatives, leading to less hydrogen bonding with H.sub.2O.

    [0005] FIG. 2 shows an illustration of H.sub.2O adsorption on LiFePO.sub.4. Higher D/G ratio leading to increased amount of carbon derivatives has an increased affinity of H.sub.2O. Also, exposed LiFePO.sub.4 area that does not have uniform carbon coatings may either form —OH termination or attract H.sub.2O with weak hydrogen bonding.

    [0006] FIG. 3 shows the chemical reaction between AlF.sub.3 and LiFePO.sub.4. The x-axis shows the molar fraction of AlF.sub.3, where x=0 is 100% LiFePO.sub.4 and x=1 is 100% AlF.sub.3. The y-axis describes the reaction enthalpy in eV/atom. The reaction enthalpy between AlF.sub.3 and LiFePO.sub.4 is rather high, which makes the decomposition reaction less favorable (i.e., AlF.sub.3 can be used as a protective coating candidate for LiFePO.sub.4 without consuming too much of cathode materials).

    [0007] FIG. 4 is a schematic illustration of various embodiments of the cathode compositions of the present technology that include a discontinuous coating, as discussed in the present disclosure

    [0008] FIG. 5 is a schematic illustration of various embodiments of the cathode compositions of the present technology that include a first coating material and a second coating material, as discussed in the present disclosure.

    [0009] FIG. 6 shows an electrode made with LiFePO.sub.4 cathode powders exposed to local environment (i.e., where surrounding moisture/H.sub.2O molecules adsorbed) that led to agglomeration (left) and modified LiFePO.sub.4 cathode materials without agglomeration (right).

    [0010] FIG. 7 is an illustration of a cross-sectional view of an electric vehicle, according to various embodiments.

    [0011] FIG. 8 is a depiction of an illustrative battery pack, according to various embodiments.

    [0012] FIG. 9 is a depiction of an illustrative battery module, according to various embodiments.

    [0013] FIGS. 10, 11, and 12 are cross sectional illustrations of various batteries, according to various embodiments.

    DETAILED DESCRIPTION

    [0014] Various embodiments are described hereinafter. It should be noted that the specific embodiments are not intended as an exhaustive description or as a limitation to the broader aspects discussed herein. One aspect described in conjunction with a particular embodiment is not necessarily limited to that embodiment and can be practiced with any other embodiment(s).

    [0015] As used herein, “about” will be understood by persons of ordinary skill in the art and will vary to some extent depending upon the context in which it is used. If there are uses of the term which are not clear to persons of ordinary skill in the art, given the context in which it is used, “about” will mean up to plus or minus 10% of the particular term.

    [0016] The phrase “and/or” as used in the present disclosure will be understood to mean any one of the recited members individually or a combination of any two or more thereof—for example, “A, B, and/or C” would mean “A, B, C, A and B, A and C, B and C, or the combination of A, B, and C.”

    [0017] The use of the terms “a” and “an” and “the” and similar referents in the context of describing the elements (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the embodiments and does not pose a limitation on the scope of the claims unless otherwise stated. No language in the specification should be construed as indicating any non-claimed element as essential.

    [0018] One option to prevent degradation in lithium ion batteries (“LIBs”) is to utilize a protective coating on the electrode active materials, particularly with regard to the cathode active materials used in the batteries. Cathode decomposition may occur during the structural phase transition (i.e., where lithium ions (de-)insert from the electrode material) and/or when in contact with other components of the LIBs, such as the electrolytes and current collectors. Illustrative commercially available cathode active materials include, but are not limited to, LiFePO.sub.4 (also referred to as LFP materials), LiMn.sub.1-xFePO.sub.4 (also referred to as LMFP materials), LiCoO.sub.2 (also referred to as LCO materials), Li(Ni.sub.aMn.sub.bCo.sub.c)O.sub.2 (also referred to as LiNMC materials), Li(Ni.sub.aCo.sub.bAl.sub.c)O.sub.2 (also referred to as LiNCA materials), Li(Ni.sub.dCo.sub.eMn.sub.fAl.sub.g+)O.sub.2 (also referred to as LiNCMA materials), and Li(Mn.sub.αNi.sub.β).sub.2O.sub.4 (also referred to as LNMO materials), where 0<x<1, a+b+c=1, d+e+f+g=1 and α+β=1.

    [0019] In general, coatings on cathode active material provide for: 1) formation of a modified solid electrolyte interface (SEI), which helps stabilize the interface between the electrode and electrolyte; 2) improvements in electrolyte wetting to ensure uniform Li+ ion insertion and de-insertion; and, 3) suppression of surface phase transitions of cathode material (i.e., surface decomposition) as a physical barrier.

    [0020] Typically, metal oxide-type coatings are used to withstand the harsh operating conditions within the LIBs. LiFePO.sub.4 tends to adsorb moisture from the surrounding due to its high surface area (e.g., composed of nano-sized primary particles and their aggregates). There are two mechanisms that can accelerate the water adsorption. The first mechanism involves hydrogen bonding formation in the surface oxygen groups of LiFePO.sub.4, especially in the uncoated area where carbon coating is not present. The second mechanism may involve the carbon coating characteristics, distribution of sp.sup.2 vs. sp.sup.3 carbon. FIG. 1 shows three different Raman spectroscopy measurements, where the intensity ratios for the absorptions of the D band (˜1350 cm.sup.−1) and G band (˜1580 cm.sup.−1) differs among the LiFePO.sub.4 samples. The D band is often referred to as the sp.sup.3 type carbon and the G band is referred to as the sp.sup.2-bonded carbon. When D/G ratio is less than 1 (i.e., higher G band intensity), it means that there are more sp.sup.2 type carbon. When D/G ratio is greater than 1 (i.e., higher D band intensity), it means that there are more sp.sup.3 carbon, as well as a great amount of carbon derivatives and surface functional groups such as —COOH, —OH, ═O, etc. Such carbon defects have higher affinity to H.sub.2O (are more hydrophilic), which makes LiFePO.sub.4 adsorb more H.sub.2O. Therefore, having LiFePO.sub.4 cathode materials with more uniform carbon with lower D/G ratio would be most ideal that would adsorb the least amount of H.sub.2O (i.e., be more hydrophobic) that can lead to reduction or elimination of problematic gelation and/or problematic agglomeration in slurry and electrode preparations.

    [0021] However, achieving uniform carbon coating on LiFePO.sub.4 without carbon defect derivatives are not an easy task. Fluoridation can help increase the hydrophobicity of oxide materials, as shown schematically in FIG. 2, where AlF.sub.3 coatings make the surface more hydrophobic than pristine LiFePO.sub.4, where oxygen atoms in LiFePO.sub.4 are likely to form hydrogen bonding with surrounding water molecules. For example, 5 nm AlF.sub.3 coatings were deposited via a chemical precipitation method on LiFePO.sub.4 cathode were shown to potentially help preserve capacity retention at 60° C. at 1 C rate when compared to pristine LiFePO.sub.4 cathodes. Furthermore, doping the oxidized surface portion with fluorine using a liquid that dissolves a fluorine-containing salt may make the fluorinated portion hydrophobic. The surface of stainless-steel metal typically contains oxide materials such as Fe.sub.2O.sub.3, Cr.sub.2O.sub.3, and NiO. It was determined that fluorinating the surface oxides in stainless steel (such as Fe.sub.2O.sub.3, Cr.sub.2O.sub.3, and NiO) led to increased H.sub.2O binding energy (i.e., more difficult for H.sub.2O to bind, where the surface is more hydrophobic vs. pristine surface). FIG. 3 shows the chemical reaction between LiFePO.sub.4 and AlF.sub.3, where the most energetically favorable chemical reaction is: [0022] 0.545LiFePO.sub.4+0.455AlF.sub.3.fwdarw.0.273Fe.sub.2PO.sub.4F+0.273AlPO.sub.4+0.182Li.sub.3AlF.sub.6
    The reaction enthalpy (E.sub.rxn) is −0.017 eV/atom. This indicates that if AlF.sub.3 is chosen as a coating for LiFePO.sub.4 cathode, AlF.sub.3 may consume Li.sup.+ ions in LiFePO.sub.4 to form Li.sub.3AlF.sub.6. In addition, LiFePO.sub.4 loses Li.sup.+ ions and picks up F.sup.− ions from AlF.sub.3 to form Fe.sub.2PO.sub.4F. Lastly, some remaining PO.sub.4.sup.−3 from LiFePO.sub.4 will lead to the formation of AlPO.sub.4. Fortunately, the reaction enthalpy is rather high (i.e., close to zero albeit a negative number), meaning that the decomposition reaction is rather slow and unfavorable (i.e., AlF.sub.3 works well as a coating for LiFePO.sub.4, as demonstrated in literature).

    [0023] Thus, in an aspect, the present technology provides a cathode composition that includes a metal fluoride (“MF.sub.x”) and/or a lithium metal fluoride (“Li-M-F”) coating on at least a portion of a surface of a particulate bulk cathode active material, where the coating includes a greater LiFePO.sub.4 stability score when normalized to that of AlF.sub.3 at 100%. In any embodiment herein, the coating may include the metal fluoride and may optionally further include a greater LiOH score when normalized to that of FeF.sub.2 at 100%. In any embodiment herein, the coating may include the metal fluoride and may optionally further include a greater HF score when normalized to that of Li.sub.2NiF.sub.4 at 100% and/or a greater PF.sub.5.sup.− score when normalized to that of Li.sub.2NiF.sub.4 at 100%. Thus, the coatings described herein provide equivalent or superior protection to that of AlF.sub.3, FeF.sub.2, and/or Li.sub.2NiF.sub.4 in the respective tested measurable statistics. The metal fluoride and/or lithium metal fluoride included in the coating may be crystalline (e.g., if more than few atomic layers) or amorphous (e.g., if very thin, or does not tend to crystallize).

    [0024] As used herein, the LiFePO.sub.4 stability score, LiOH score, PF.sub.5.sup.− score, and HF score are determined based upon the model reaction that is to be run, as discussed in the working examples. For example, the molar ratio of components (MF.sub.x or Li-M-F) to LiFePO.sub.4 is first determined (ratio 1). The ratio is then normalized to the ratio for the baseline reaction of AlF.sub.3 by dividing ratio 1 (for AlF.sub.3) by ratio 1 (for the MF.sub.x or Li-M-F of interest) to arrive at value 1. The enthalpy of reaction (E.sub.rxn) in eV/atom is then determined from the calculation, however this is then normalized to the E.sub.rxn for AlF.sub.3 dividing the E.sub.rxn (for the MF.sub.x or Li-M-F of interest) by E.sub.rxn (for AlF.sub.3) to arrive at value 2. Value 1 and 2 are then summed, however they are based upon molar ratios. To convert the values to weight-based values, the sum is then divided by the molecular weight of the MF.sub.x or Li-M-F multiplied by 1000. The LiFePO.sub.4 stability score is then determined by dividing the per weight value for the AlF.sub.3 by the per weight value of the MF.sub.x or Li-M-F multiplied by 100. Expressed another way, the LiFePO.sub.4 stability score is a percentage improvement (or diminution) for that reaction compared to the baseline AlF.sub.3 value. Illustrative calculations are shown in the examples.

    [0025] In any embodiment herein, the metal fluoride may include MgF.sub.2, MnF.sub.2, FeF.sub.2, SrF.sub.2, MoF.sub.3, LaF.sub.3, NdF.sub.3, or a mixture of any two or more thereof. In any embodiment herein, the metal fluoride may include SrF.sub.2, LaF.sub.3, NdF.sub.3, or a mixture of any two or more thereof. In any embodiment herein, the metal fluoride may include MgF.sub.2, MnF.sub.2, FeF.sub.2, MoF.sub.3, or a mixture of any two or more thereof. In any embodiment herein, the lithium metal fluoride may include Li.sub.3AlF.sub.6, Li.sub.3ScF.sub.6, Li.sub.2NiF.sub.4, LiYF.sub.4, LiInF.sub.4, Li.sub.2SnF.sub.6, LiCeF.sub.5, LiBiF.sub.4, Li.sub.3FeF.sub.6, or a mixture of any two or more thereof. In any embodiment herein, the lithium metal fluoride may include Li.sub.3AlF.sub.6, Li.sub.3ScF.sub.6, Li.sub.2NiF.sub.4, LiBiF.sub.4, Li.sub.3FeF.sub.6, or a mixture of any two or more thereof. In any embodiment herein, the coating may include LiYF.sub.4, LiInF.sub.4, Li.sub.2SnF.sub.6, LiCeF.sub.5, or a mixture of any two or more thereof. In any embodiment herein, the coating may include LiFePO.sub.4. Such coating materials of any embodiment herein are used at a level sufficient to provide additional protection to the cathode material. For example, this may include where the metal fluoride, the lithium metal fluoride, or both the metal fluoride and the lithium metal fluoride is present from about 0.01 wt % to about 5.0 wt %. The thickness of the coating may also play in role in durability, but it may also be a hindrance to current flow. Accordingly, the coating may have an average thickness on the particulate bulk cathode active material of about 5 nm to about 2 μm. In any embodiment herein, the coating may be continuous or discontinuous. Referring to FIG. 4, in some embodiments the coating 2010 may include discontinuous regions 2015 of coating on the particulate bulk cathode active material 2020. It is understood that in the commercial coating of the particulate bulk cathode active materials, commercial coating materials may include voids and other irregularities on the surface of the particulate bulk cathode active material. As the coating material is deposited onto the particulate bulk cathode active material, it may nucleate near grain boundaries of the particulate bulk cathode active material.

    [0026] Referring to FIG. 5, in some embodiments, the coating may comprise a first coating material 1010 and a second coating material 1025. The first coating material 1010 may include discontinuous regions 1015 of coating on the particulate bulk cathode active material 1020, and where a portion of the second coating material 1025 is formed in the discontinuous regions 1015 of the first coating material. In other embodiments, a portion of the second coating material 1025 is formed in the discontinuous regions 1015 of the first coating material 1010 and has a greater thickness than other portions of the coating formed as an overcoating.

    [0027] In any of the above embodiments, the second coating material may overcoat the first coating material, fill in voids of the first coating material on the surface of the particulate bulk cathode active material, or both overcoats the first coating material and fill in voids of the first coating material on the surface of the particulate bulk cathode active material, and the second coating material may be different from the first coating material as well as the particulate bulk cathode active material. The particulate bulk cathode active material may be a single crystal, polycrystalline, or blended (e.g., different size of single crystals, polycrystals, or mixture of single- and polycrystals), where the first and/or second coating material may be different based on the size, morphology, and/or crystallinity.

    [0028] It is understood that in the commercial coating of the particulate bulk cathode active materials, commercial (i.e. the first) coating materials include voids and other irregularities on the surface of the particulate bulk cathode active material. As the second coating material is deposited onto the particulate bulk cathode active material, they typically nucleate near grain boundaries of the first coating material or the particulate bulk cathode active material. For example, they may deposit on the particulate bulk cathode active material next to the first coating material. They may also then fill the voids or uncoated areas from the first coating deposition and grow in thickness in those areas as the deposition proceeds. Where the second coating material is deposited on top of the first coating material, the second coating material may be thinner. For example, in some embodiments, a thickness of the first and/or second coating material may be about 5 nm to about 2 μm. The first coating material may formed in discontinuous regions on the surface of the particulate bulk cathode active material, and the second coating material, may be formed in the discontinuous regions of the first coating material. A portion of the second coating material formed in the discontinuous regions of the first coating coating material may have a greater thickness than other portions of the second coating material formed as an overcoating.

    [0029] In any embodiment including a first coating material and a second coating material, the second coating material may be different from the first coating material and from the particulate bulk cathode active material. In any of the above embodiments, the first coating material may include a carbon coating, one or more metal phosphate(s) (for example, including AlPO.sub.4), one or more lithium metal phosphate(s) (e.g., a lithium metal phosphate where the metal is a transition or non-transition metal/metalloid with the excluding noble metals, rare earth elements, and radioactive elements, such as LiFePO.sub.4), a metal fluoride (such as AlF.sub.3, MgF.sub.2, MnF.sub.2, FeF.sub.2, SrF.sub.2, MoF.sub.3, LaF.sub.3, NdF.sub.3, or a mixture of any two or more thereof), and/or a lithium metal fluoride (such as Li.sub.3AlF.sub.6, Li.sub.3ScF.sub.6, Li.sub.2NiF.sub.4, LiYF.sub.4, LiInF.sub.4, Li.sub.2SnF.sub.6, LiCeF.sub.5, LiBiF.sub.4, Li.sub.3FeF.sub.6, or a mixture of any two or more thereof); and the second coating material may include MgF.sub.2, MnF.sub.2, FeF.sub.2, SrF.sub.2, MoF.sub.3, LaF.sub.3, NdF.sub.3, Li.sub.3AlF.sub.6, Li.sub.3ScF.sub.6, Li.sub.2NiF.sub.4, LiYF.sub.4, LiInF.sub.4, Li.sub.2SnF.sub.6, LiCeF.sub.5, LiBiF.sub.4, Li.sub.3FeF.sub.6, or a mixture of any two or more thereof.

    [0030] As noted above, the cathode composition includes a particulate bulk cathode active material. As used herein, the particulate bulk cathode active material is the core of the particle that is coated with a thin layer of the metal fluoride and/or lithium metal fluoride coating on the surface. Generally, the particulate bulk cathode material may include one or more olivine-type cathode active materials (such as LFP and/or LMFP) and/or may include a nickel-rich cathode active material. Olivine-type cathode active materials may be nano-sized particles with a relatively high surface area, where H.sub.2O from surrounding environment (e.g., moisture) may adsorb easily; for nickel-rich cathode active materials, a Ni-rich surface may rapidly react with oxygen and/or H.sub.2O to transform to Ni-rich carbonate-like structures that may cause process issues (e.g. gelation) during slurry formation. Illustrative particulate bulk cathode active materials include materials such as lithium nickel manganese cobalt oxide (“LiNMC”), lithium nickel manganese oxide, lithium cobalt oxide (LCO), LiNCA, LiNCMA, or mixtures of any two or more thereof. In some embodiments, the particulate bulk cathode active material may include Li(Ni.sub.aMn.sub.bCo.sub.c)O.sub.2, wherein 0≤a≤1, 0≤b≤1, 0≤c≤1, and a+b+c=1. In some embodiments, the particulate bulk cathode active material may include Li(Ni.sub.aMn.sub.bCo.sub.c)O.sub.2, wherein 0<a<1, 0<b<1, 0<c<1, and a+b+c=1. In any embodiment herein, the particulate bulk cathode active material may include LiCoO.sub.2, Li(Ni.sub.aMn.sub.bCo.sub.c)O.sub.2, Li(Mn.sub.αNi.sub.β).sub.2O.sub.4, or a mixture of any two or more thereof, wherein a+b+c=1, and α+β=1. In any embodiment herein, the particulate bulk cathode active material may include a Li-rich Mn-rich material such as Li.sub.1+x(Ni.sub.aMn.sub.bCo.sub.c).sub.1-xO.sub.2 where 0<x<0.4 and a+b+c=1. In any embodiment herein, the particulate bulk cathode active material may include LiCoO.sub.2, Li(Ni.sub.aMn.sub.bCo.sub.c)O.sub.2, Li(Mn.sub.αNi.sub.β).sub.2O.sub.4, or a mixture of any two or more thereof, wherein 0<a<1, 0≤b<1, 0≤c<1, a+b+c=1, 0≤α<1, 0<β<1, and α+β=1. As used herein, nickel-rich cathodes are cathode active materials include 70 wt % or greater of nickel, and may include materials with greater than 80 wt % nickel.

    [0031] Alternatively, or in addition, to a coating of metal fluoride and/or lithium metal fluoride on the bulk cathode active material, the metal fluoride and/or lithium metal fluoride may be coated or deposited on other surfaces within a battery cell or within a battery pouch or within a battery housing. Accordingly, in other aspects, the metal fluoride and/or lithium metal fluoride may be used as a coating on a current collector, on the separator, inside a pouch, or inside a housing.

    [0032] In another aspect, a current collector includes a metal that is at least partially coated with a metal fluoride and/or lithium metal fluoride where the coating includes a greater LiFePO.sub.4 stability score when normalized to that of AlF.sub.3 at 100%. In any embodiment herein, the coating may include the metal fluoride and may optionally further include a greater LiOH score when normalized to that of FeF.sub.2 at 100%. In any embodiment herein, the coating may include the metal fluoride and may optionally further include a greater HF score when normalized to that of Li.sub.2NiF.sub.4 at 100% and/or a greater PF.sub.5.sup.− score when normalized to that of Li.sub.2NiF.sub.4 at 100%. In any embodiment herein, the metal fluoride may include MgF.sub.2, MnF.sub.2, FeF.sub.2, SrF.sub.2, MoF.sub.3, LaF.sub.3, NdF.sub.3, or a mixture of any two or more thereof. In any embodiment herein, the metal fluoride may include SrF.sub.2, LaF.sub.3, NdF.sub.3, or a mixture of any two or more thereof. In any embodiment herein, the metal fluoride may include MgF.sub.2, MnF.sub.2, FeF.sub.2, MoF.sub.3, or a mixture of any two or more thereof. In any embodiment herein, the lithium metal fluoride may include Li.sub.3AlF.sub.6, Li.sub.3ScF.sub.6, Li.sub.2NiF.sub.4, LiYF.sub.4, LiInF.sub.4, Li.sub.2SnF.sub.6, LiCeF.sub.5, LiBiF.sub.4, Li.sub.3FeF.sub.6, or a mixture of any two or more thereof. In any embodiment herein, the lithium metal fluoride may include Li.sub.3AlF.sub.6, Li.sub.3ScF.sub.6, Li.sub.2NiF.sub.4, LiBiF.sub.4, Li.sub.3FeF.sub.6, or a mixture of any two or more thereof. In any embodiment herein, the coating may include LiYF.sub.4, LiInF.sub.4, Li.sub.2SnF.sub.6, LiCeF.sub.5, or a mixture of any two or more thereof. In any embodiment herein, the coating may include LiFePO.sub.4. In any embodiment herein, about 0.1 wt % to about 5 wt % of the metal fluoride, the lithium metal fluoride, or both the metal fluoride and the lithium metal fluoride may be included. In any embodiment herein, the coating may include an average thickness on the particulate bulk cathode active material of about 5 nm to about 2 μm.

    [0033] The current collector may include a metal that is aluminum, copper, nickel, titanium, stainless steel, or carbonaceous materials. In some embodiments, the metal of the current collector is in the form of a metal foil. In some specific embodiments, the current collector is an aluminum (Al) or copper (Cu) foil. In some embodiments, the current collector is a metal alloy, made of Al, Cu, Ni, Fe, Ti, or combination thereof. In some embodiments, the metal foils maybe coated with carbon: e.g., carbon-coated Al foil, and the like.

    [0034] The materials described herein are all intended for use in electrochemical devices such as, but not limited to, lithium ion batteries. Accordingly, in another aspect, the present technology provides an electrochemical cell, such as a lithium ion battery (e.g., a lithium secondary battery), that includes a cathode including a particulate bulk cathode active material and optionally a current collector and the lithium ion battery may optionally include a housing. Where the electrochemical cell is a lithium ion battery, the lithium ion battery may also optionally include an anode, a separator, an electrolyte, or a combination of any two or more thereof. The housing may be a pouch in which a battery cell is contained, or it may be the housing the battery in which the pouches are contained. In the lithium ion battery, one or more of the cathode active material, the current collector, or an inner surface of the housing is at least partially coated with a metal fluoride and/or lithium metal fluoride, where the coating includes a greater LiFePO.sub.4 stability score when normalized to that of AlF.sub.3 at 100%. In any embodiment herein, the coating may include the metal fluoride and may optionally further include a greater LiOH score when normalized to that of FeF.sub.2 at 100%. In any embodiment herein, the coating may include the metal fluoride and may optionally further include a greater HF score when normalized to that of Li.sub.2NiF.sub.4 at 100% and/or a greater PF.sub.5.sup.− score when normalized to that of Li.sub.2NiF.sub.4 at 100%. In any embodiment herein, the metal fluoride may include MgF.sub.2, MnF.sub.2, FeF.sub.2, SrF.sub.2, MoF.sub.3, LaF.sub.3, NdF.sub.3, or a mixture of any two or more thereof. In any embodiment herein, the metal fluoride may include SrF.sub.2, LaF.sub.3, NdF.sub.3, or a mixture of any two or more thereof. In any embodiment herein, the metal fluoride may include MgF.sub.2, MnF.sub.2, FeF.sub.2, MoF.sub.3, or a mixture of any two or more thereof. In any embodiment herein, the lithium metal fluoride may include Li.sub.3AlF.sub.6, Li.sub.3ScF.sub.6, Li.sub.2NiF.sub.4, LiYF.sub.4, LiInF.sub.4, Li.sub.2SnF.sub.6, LiCeF.sub.5, LiBiF.sub.4, Li.sub.3FeF.sub.6, or a mixture of any two or more thereof. In any embodiment herein, the lithium metal fluoride may include Li.sub.3AlF.sub.6, Li.sub.3ScF.sub.6, Li.sub.2NiF.sub.4, LiBiF.sub.4, Li.sub.3FeF.sub.6, or a mixture of any two or more thereof. In any embodiment herein, the coating may include LiYF.sub.4, LiInF.sub.4, Li.sub.2SnF.sub.6, LiCeF.sub.5, or a mixture of any two or more thereof. In any embodiment herein, the coating may include LiFePO.sub.4. In any embodiment herein, the coating may about 0.1 wt % to about 5 wt % of the metal fluoride, the lithium metal fluoride, or both the metal fluoride and the lithium metal fluoride. In any embodiment herein, the coating may include an average thickness on the particulate bulk cathode active material of about 5 nm to about 2 μm.

    [0035] The cathodes may include, in addition to the particulate bulk cathode active material, one or more of a current collector, a conductive carbon, a binder, or other additives. The anodes of the electrochemical cells may include lithium. In some embodiments, the anodes may also include a current collector, a conductive carbon, a binder, and other additives, as described above with regard to the cathode current collectors, conductive carbon, binders, and other additives. In some embodiments, the electrode may comprise a current collector (e.g., Cu foil) with an in situ-formed anode (e.g., Li metal) on a surface of the current collector facing the separator or solid-state electrolyte such that in an uncharged state, the assembled cell does not comprise an anode active material.

    [0036] The cathodes and anodes may also each contain, independently of each other, other materials such as conductive carbon materials, current collectors, binders, and other additives. Illustrative conductive carbon species include graphite, carbon black, Super P carbon black material, Ketjen Black, Acetylene Black, SWCNT, MWCNT, graphite, carbon nanofiber, and/or graphene, graphite. Illustrative binders may include, but are not limited to, polymeric materials such as polyvinylidenefluoride (“PVDF”), polyvinylpyrrolidone (“PVP”), styrene-butadiene or styrene-butadiene rubber (“SBR”), polytetrafluoroethylene (“PTFE”) or carboxymethylcellulose (“CMC”). Other illustrative binder materials can include one or more of: agar-agar, alginate, amylose, Arabic gum, carrageenan, caseine, chitosan, cyclodextrines (carbonyl-beta), ethylene propylene diene monomer (EPDM) rubber, gelatine, gellan gum, guar gum, karaya gum, cellulose (natural), pectine, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT-PSS), polyacrilic acid (PAA), poly(methyl acrylate) (PMA), poly(vinyl alcohol) (PVA), poly(vinyl acetate) (PVAc), polyacrylonitrile (PAN), polyisoprene (PIpr), polyaniline (PANi), polyethylene (PE), polyimide (PI), polystyrene (PS), polyurethane (PU), polyvinyl butyral (PVB), polyvinyl pyrrolidone (PVP), starch, styrene butadiene rubber (SBR), tara gum, tragacanth gum, fluorine acrylate (TRD202A), xanthan gum, or mixtures of any two or more thereof. The current collector may include a metal that is aluminum, copper, nickel, titanium, stainless steel, or carbonaceous materials. In some embodiments, the metal of the current collector is in the form of a metal foil. In some specific embodiments, the current collector is an aluminum (Al) or copper (Cu) foil. In some embodiments, the current collector is a metal alloy, made of Al, Cu, Ni, Fe, Ti, or combination thereof. In another embodiment, the metal foils maybe coated with carbon: e.g., carbon-coated Al foil and the like.

    [0037] In another aspect, a process for manufacturing a cathode for a lithium ion battery is provided. The process includes mixing a metal fluoride and/or lithium metal fluoride coated particulate bulk cathode active material (of any embodiment of the present technology) with conductive carbon and a binder in a solvent to form a slurry, coating the slurry onto a cathode current collector, and removing the solvent.

    [0038] Generally, the conductive carbon species may include graphite, carbon black, carbon nanotubes, and the like. Illustrative conductive carbon species include graphite, carbon black, Super P carbon black material, Ketjen Black, Acetylene Black, SWCNT, MWCNT, graphite, carbon nanofiber, and/or graphene, graphite.

    [0039] Illustrative binders may include, but are not limited to, polymeric materials such as polyvinylidenefluoride (“PVDF”), polyvinylpyrrolidone (“PVP”), styrene-butadiene or styrene-butadiene rubber (“SBR”), polytetrafluoroethylene (“PTFE”) or carboxymethylcellulose (“CMC”). Other illustrative binder materials can include one or more of: agar-agar, alginate, amylose, Arabic gum, carrageenan, caseine, chitosan, cyclodextrines (carbonyl-beta), ethylene propylene diene monomer (EPDM) rubber, gelatine, gellan gum, guar gum, karaya gum, cellulose (natural), pectine, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT-PSS), polyacrilic acid (PAA), poly(methyl acrylate) (PMA), poly(vinyl alcohol) (PVA), poly(vinyl acetate) (PVAc), polyacrylonitrile (PAN), polyisoprene (PIpr), polyaniline (PANi), polyethylene (PE), polyimide (PI), polystyrene (PS), polyurethane (PU), polyvinyl butyral (PVB), polyvinyl pyrrolidone (PVP), starch, styrene butadiene rubber (SBR), tara gum, tragacanth gum, fluorine acrylate (TRD202A), xanthan gum, or mixtures of any two or more thereof. The current collector may include a metal that is aluminum, copper, nickel, titanium, stainless steel, or carbonaceous materials. In some embodiments, the metal of the current collector is in the form of a metal foil. In some specific embodiments, the current collector is an aluminum (Al) or copper (Cu) foil. In some embodiments, the current collector is a metal alloy, made of Al, Cu, Ni, Fe, Ti, or combination thereof. In another embodiment, the metal foils maybe coated with carbon: e.g., carbon-coated Al foil and the like.

    [0040] The solvent used in the slurry formation may be a ketone, an ether, a heterocyclic ketone, and/or distilled water. One illustrative solvent is N-methylpyrrolidone (“NMP”). The solvent may be removed by allowing the solvent to evaporate at ambient or elevated temperature, or at ambient pressure or reduced pressure. Handling of the cathode and other lithium ion battery internal components may be conducted under an inert atmosphere (N.sub.2, Ar, etc.) and/or conducted under an reducing atmosphere (e.g., H.sub.2), according to some embodiments. In some embodiments, vacuum-assisted heat treatment conditions may be utilized. Due to the hydrophobic nature of MF.sub.x and Li-M-F coatings, agglomeration and/or gelation caused by adsorption of H.sub.2O molecules in the electrodes may be significantly reduced, as depicted in FIG. 6.

    [0041] In any embodiment herein, a metal-containing precursor chemical including but not limited to metal nitrates, chloride, sulfate, etc. may be dissolved in water or an organic solvent. In some embodiments, LiOH and/or NH.sub.4F may be added to the mixture. In some embodiments, the solution may be mixed with LiFePO.sub.4 precursors (including carbon coating sources such as sucrose or citric acid) at room temperature or elevated temperature with an aging time varying from 5 min to 24 hours. The nominal MF.sub.x or Li-M-F may be targeted to be from about 0.1 wt % to about 5 wt % of the LiFePO.sub.4 powders. The pH of the solution may be controlled by the presence of acid or base in order to precipitate well-mixed precursor compounds. The mixture may be annealed at elevated temperature may be any of the following values or in a range of any two of the following values: 200° C., 400° C., 600° C., 800° C., and 1,000° C. The aging time may be any of the following values or in a range of any two of the following values: 1, 2, 3, 4, 8, 12, 16, 24, 36, 48, 60 and 72 hours.

    [0042] In any embodiment herein, variously sized MF.sub.x or Li-M-F containing LiFePO.sub.4 cathode materials may be synthesized via a solid-state method. The primary particle size range for LiFePO.sub.4 may any of the following values or in a range of any two of the following values: 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, and 200 nm. In some embodiments, the secondary size range may any of the following values or in a range of any two of the following values: 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, and 20 μm. One exemplary, but not limiting, method of performing solid-state synthesis is a ball-milling process. In some embodiments, the solid-state method may be followed by an optional spray dryer processing step to facilitate the drying and secondary particle formation. The optimal amount of metal fluorides and/or lithium metal fluorides and its chemical composition at the electrode material surface may be tuned by the secondary heat-treatment conditions that may be any of the following values or in a range of any two of the following values: 200° C., 400° C., 600° C., 800° C., and 1,000° C. in the presence of reducing gas such as N.sub.2, Ar, H.sub.2, or gas mixture thereof. A person of ordinary skill in the art based on the present disclosure would readily understand that, depending on the particular cathode active material (e.g., LiNMC, LCO, LiNCA, LiNCMA, LNMO, Li.sub.1+x(Ni.sub.aMn.sub.bCo.sub.c).sub.1-xO.sub.2, or mixtures of any two or more thereof), heat treatment conditions may be oxidizing in the presence of oxidizing gas such as Air, O.sub.2, or gas mixture thereof.

    [0043] In other embodiments, metal fluoride or Li-M-F coating materials may be deposited on the synthesized electrode active materials, as a post-treatment step. Non-limiting examples of deposition techniques include chemical vapor deposition, etching techniques, physical vapor deposition, pulsed laser deposition, emulsion, sol-gel, atomic layer deposition, and/or other deposition techniques. In some embodiments, such as atomic layer deposition, the choice of precursor chemicals may be limited to certain chemical composition as readily appreciated by a person of ordinary skill in the art.

    [0044] In any embodiment herein, the loading level of cathode materials may vary from about 5 mg/cm.sup.2 to about 50 mg/cm.sup.2 and the packing density may vary from about 1.0 g/cc to about 5.0 g/cc. In some embodiments, the electrode may be assembled as the cathode in Li-ion batteries, where the anode materials may be Li metal, graphite, Si, SiO.sub.x, Si nanowire, lithiated Si, or mixture thereof. In some embodiments, a traditional liquid electrolyte including lithium hexafluorophosphate (LiPF.sub.6) dissolved in a carbonate solution may be used. In other embodiments, a solid state electrolyte including but not limited to a polymer and/or an oxide, sulfide, and/or phosphate-based crystalline structure may replace the liquid electrolyte. The cell configuration may be prismatic, cylindrical, or pouch type. Each cell can further configure together to design pack, module, or stack with desired power output.

    [0045] In another aspect, the present disclosure provides a battery pack comprising the cathode active material, the electrochemical cell, or the lithium ion battery of any one of the above embodiments. The battery pack may find a wide variety of applications including but are not limited to general energy storage or in vehicles.

    [0046] In another aspect, a plurality of battery cells as described above may be used to form a battery and/or a battery pack that may find a wide variety of applications such as general storage, or in vehicles. By way of illustration of the use of such batteries or battery packs in an electric vehicle, FIG. 7 depicts is an example cross-sectional view 100 of an electric vehicle 105 installed with at least one battery pack 110. Electric vehicles 105 can include electric trucks, electric sport utility vehicles (SUVs), electric delivery vans, electric automobiles, electric cars, electric motorcycles, electric scooters, electric passenger vehicles, electric passenger or commercial trucks, hybrid vehicles, or other vehicles such as sea or air transport vehicles, planes, helicopters, submarines, boats, or drones, among other possibilities. The battery pack 110 can also be used as an energy storage system to power a building, such as a residential home or commercial building. Electric vehicles 105 can be fully electric or partially electric (e.g., plug-in hybrid) and further, electric vehicles 105 can be fully autonomous, partially autonomous, or unmanned. Electric vehicles 105 can also be human operated or non-autonomous. Electric vehicles 105 such as electric trucks or automobiles can include on-board battery packs 110, battery modules 115, or battery cells 120 to power the electric vehicles. The electric vehicle 105 can include a chassis 125 (e.g., a frame, internal frame, or support structure). The chassis 125 can support various components of the electric vehicle 105. The chassis 125 can span a front portion 130 (e.g., a hood or bonnet portion), a body portion 135, and a rear portion 140 (e.g., a trunk, payload, or boot portion) of the electric vehicle 105. The battery pack 110 can be installed or placed within the electric vehicle 105. For example, the battery pack 110 can be installed on the chassis 125 of the electric vehicle 105 within one or more of the front portion 130, the body portion 135, or the rear portion 140. The battery pack 110 can include or connect with at least one busbar, e.g., a current collector element. For example, the first busbar 145 and the second busbar 150 can include electrically conductive material to connect or otherwise electrically couple the battery modules 115 or the battery cells 120 with other electrical components of the electric vehicle 105 to provide electrical power to various systems or components of the electric vehicle 105.

    [0047] FIG. 8 depicts an example battery pack 110. Referring to FIG. 7, among others, the battery pack 110 can provide power to electric vehicle 105. Battery packs 110 can include any arrangement or network of electrical, electronic, mechanical, or electromechanical devices to power a vehicle of any type, such as the electric vehicle 105. The battery pack 110 can include at least one housing 205. The housing 205 can include at least one battery module 115 or at least one battery cell 120, as well as other battery pack components. The housing 205 can include a shield on the bottom or underneath the battery module 115 to protect the battery module 115 from external conditions, for example if the electric vehicle 105 is driven over rough terrains (e.g., off-road, trenches, rocks, etc.) The battery pack 110 can include at least one cooling line 210 that can distribute fluid through the battery pack 110 as part of a thermal/temperature control or heat exchange system that can also include at least one cold plate 215. The cold plate 215 can be positioned in relation to a top submodule and a bottom submodule, such as in between the top and bottom submodules, among other possibilities. The battery pack 110 can include any number of cold plates 215. For example, there can be one or more cold plates 215 per battery pack 110, or per battery module 115. At least one cooling line 210 can be coupled with, part of, or independent from the cold plate 215.

    [0048] FIG. 9 depicts example battery modules 115, and FIG. 10 depicts an illustrative cross sectional view of a battery cell 120. The battery modules 115 can include at least one submodule. For example, the battery modules 115 can include at least one first (e.g., top) submodule 220 or at least one second (e.g., bottom) submodule 225. At least one cold plate 215 can be disposed between the top submodule 220 and the bottom submodule 225. For example, one cold plate 215 can be configured for heat exchange with one battery module 115. The cold plate 215 can be disposed or thermally coupled between the top submodule 220 and the bottom submodule 225. One cold plate 215 can also be thermally coupled with more than one battery module 115 (or more than two submodules 220, 225). The battery submodules 220, 225 can collectively form one battery module 115. In some examples each submodule 220, 225 can be considered as a complete battery module 115, rather than a submodule.

    [0049] The battery modules 115 can each include a plurality of battery cells 120. The battery modules 115 can be disposed within the housing 205 of the battery pack 110. The battery modules 115 can include battery cells 120 that are cylindrical cells (e.g., FIG. 10) or prismatic cells (e.g., FIG. 11), for example. The battery module 115 can operate as a modular unit of battery cells 120. For example, a battery module 115 can collect current or electrical power from the battery cells 120 that are included in the battery module 115 and can provide the current or electrical power as output from the battery pack 110. The battery pack 110 can include any number of battery modules 115. For example, the battery pack can have one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve or other number of battery modules 115 disposed in the housing 205. It should also be noted that each battery module 115 may include a top submodule 220 and a bottom submodule 225, possibly with a cold plate 215 in between the top submodule 220 and the bottom submodule 225. The battery pack 110 can include or define a plurality of areas for positioning of the battery module 115. The battery modules 115 can be square, rectangular, circular, triangular, symmetrical, or asymmetrical. In some examples, battery modules 115 may be different shapes, such that some battery modules 115 are rectangular but other battery modules 115 are square shaped, among other possibilities. The battery module 115 can include or define a plurality of slots, holders, or containers for a plurality of battery cells 120.

    [0050] As noted above, battery cells 120 have a variety of form factors, shapes, or sizes. For example, battery cells 120 may have a cylindrical, rectangular, square, cubic, flat, or prismatic form factor. FIGS. 10, 11, and 12 depict illustrative cross sectional views of battery cells 120 in such various form factors. For example FIG. 10 is a cylindrical cell, FIG. 11 is a prismatic cell, and FIG. 12 is the cell for use in a pouch. The battery cells 120 may be assembled by inserting a wound or stacked electrode roll (e.g., a jellyroll) including a separator (e.g., polymeric sheet) or electrolyte material (e.g., solid state electrolyte) into at least one battery cell housing 230. The electrolyte material, e.g., an ionically conductive fluid or other material, may generate or provide electric power for the battery cell 120. In an embodiment, the separator is wetted by a liquid electrolyte during a liquid electrolyte filling operation after insertion of the jellyroll. A first portion of the electrolyte material may have a first polarity, and a second portion of the electrolyte material may have a second polarity. The housing 230 may be of various shapes, including cylindrical or rectangular, for example. Electrical connections may be made between the electrolyte material and components of the battery cell 120. For example, electrical connections with at least some of the electrolyte material may be formed at two points or areas of the battery cell 120, for example to form a first polarity terminal 235 (e.g., a positive or anode terminal) and a second polarity terminal 240 (e.g., a negative or cathode terminal). The polarity terminals may be made from electrically conductive materials to carry electrical current from the battery cell 120 to an electrical load, such as a component or system of the electric vehicle 105.

    [0051] The battery cell 120 can be included in battery modules 115 or battery packs 110 to power components of the electric vehicle 105. The battery cell housing 230 can be disposed in the battery module 115, the battery pack 110, or a battery array installed in the electric vehicle 105. The housing 230 can be of any shape, such as cylindrical with a circular (e.g., as depicted), elliptical, or ovular base, among others. The shape of the housing 230 can also be prismatic with a polygonal base, such as a triangle, a square, a rectangle, a pentagon, and a hexagon, among others.

    [0052] The housing 230 of the battery cell 120 can include one or more materials with various electrical conductivity or thermal conductivity, or a combination thereof. The electrically conductive and thermally conductive material for the housing 230 of the battery cell 120 can include a metallic material, such as aluminum, an aluminum alloy with copper, silicon, tin, magnesium, manganese, or zinc (e.g., aluminum 1000, 4000, or 5000 series), iron, an iron-carbon alloy (e.g., steel), silver, nickel, copper, and a copper alloy, among others. The electrically insulative and thermally conductive material for the housing 230 of the battery cell 120 can include a ceramic material (e.g., silicon nitride, silicon carbide, titanium carbide, zirconium dioxide, beryllium oxide, and among others) and a thermoplastic material (e.g., polyethylene, polypropylene, polystyrene, polyvinyl chloride, or nylon), among others.

    [0053] The battery cell 120 may include at least one anode layer 245, which may be disposed within the cavity 250 defined by the housing 230. The anode layer 245 may receive electrical current into the battery cell 120 and output electrons during the operation of the battery cell 120 (e.g., charging or discharging of the battery cell 120). The anode layer 245 may include an active substance.

    [0054] The battery cell 120 may include at least one cathode layer 255 (e.g., a composite cathode layer compound cathode layer, a compound cathode, a composite cathode, or a cathode). The cathode layer 255 may be disposed within the cavity 250. The cathode layer 255 may output electrical current out from the battery cell 120 and may receive electrons during the discharging of the battery cell 120. The cathode layer 255 may also release lithium ions during the discharging of the battery cell 120. Conversely, the cathode layer 255 may receive electrical current into the battery cell 120 and may output electrons during the charging of the battery cell 120. The cathode layer 255 may receive lithium ions during the charging of the battery cell 120.

    [0055] The battery cell 120 may include a polymer separator comprising a liquid electrolyte in the case of Li-ion batteries or a solid-state electrolyte layer 260 in the case of solid-state batteries, disposed within the cavity 250. The separator or solid-state electrolyte layer 260 may be arranged between the anode layer 245 and the cathode layer 255 to separate the anode layer 245 and the cathode layer 255. The liquid electrolyte or solid-state electrolyte layer 260 may transfer ions between the anode layer 245 and the cathode layer 255. The liquid or solid electrolytes can transfer cations (e.g., Li.sup.+ ions) from the anode layer 245 to the cathode layer 255 during a discharge operation of the battery cell 120. The liquid or solid electrolyte can transfer cations (e.g., Li.sup.+ ions) from the cathode layer 255 to the anode layer 245 during a charge operation of the battery cell 120.

    [0056] FIG. 11 is an illustration of a prismatic battery cell 120. The prismatic battery cell 120 may have a housing 230 that defines a rigid enclosure. The housing 230 may have a polygonal base, such as a triangle, square, rectangle, pentagon, among others. For example, the housing 230 of the prismatic battery cell 120 may define a rectangular box. The prismatic battery cell 120 may include at least one anode layer 245, at least one cathode layer 255, and at least one separator and electrolyte or an electrolyte layer 260 disposed within the housing 230. The prismatic battery cell 120 may include a plurality of anode layers 245, cathode layers 255, and separator or electrolyte layers 260. For example, the layers 245, 255, 260 may be stacked or in a form of a flattened spiral. The prismatic battery cell 120 may include an anode tab 265. The anode tab 265 may contact the anode layer 245 and facilitate energy transfer between the prismatic battery cell 120 and an external component. For example, the anode tab 265 may exit the housing 230 or electrically couple with a positive terminal 235 to transfer energy between the prismatic battery cell 120 and an external component.

    [0057] The battery cell 120 may also include a pressure vent 270. The pressure vent 270 may be disposed in the housing 230. The pressure vent 270 may provide pressure relief to the battery cell 120 as pressure increases within the battery cell 120. For example, gases may build up within the housing 230 of the battery cell 120. The pressure vent 270 may provide a path for the gases to exit the housing 230 when the pressure within the battery cell 120 reaches a threshold.

    [0058] The present technology, thus generally described, will be understood more readily by reference to the following examples, which are provided by way of illustration and are not intended to be limiting of the present technology.

    EXAMPLES

    [0059] General. First-principles density functional theory (DFT)-based methodologies can be used to determine, understand, and pre-select MF compounds and Li-M-F compounds for coating materials. The DFT algorithms are used calculate the thermodynamic stability of the materials, to identify those material shaving stable ground state structures vs. high-energy structures.

    [0060] The screening strategy employed the following criteria to identify additional protective coating materials and compare them to AlF.sub.3 as an illustrative example of a coating material. The criteria included: (a) cathode stability by predicting an equilibrium or no reaction with illustrative cathode material LiFePO.sub.4; (b) stability against H.sub.2O; and (c) electrolyte stability by predicting an equilibrium or no reaction with HF, PF.sub.5.sup.−, LiF, and LiOH.

    [0061] Here, first-principles density functional theory (DFT) methodologies are used to model the stability of AlF.sub.3 and LiFePO.sub.4 cathode materials using the interface app in materialproject.org, an open access materials database that is open to public.

    [0062] The chemical stability for 74 M.sub.xF.sub.y compounds was tested against LiFePO.sub.4, as shown in Table 1. Table 1 shows the chemical reaction of a MF.sub.x and its corresponding reaction enthalpy when in contact with LiFePO.sub.4.

    TABLE-US-00001 TABLE 1 Chemical stability MF.sub.x with LiFePO.sub.4. MW E.sub.rxn MF.sub.x (g/mol) LiFePO.sub.4 Stability (eV/atom) LiF 25.94 Stable 0.000 NaF 41.99 0.667 NaF + 0.333 LiFePO.sub.4 .fwdarw. 0.333 Na.sub.2FePO.sub.4F + 0.333 LiF −0.009 MgF.sub.2 62.3 Stable 0.000 AlF.sub.3 83.98 0.545 LiFePO.sub.4 + 0.455 AlF.sub.3 .fwdarw. 0.273 Fe.sub.2PO.sub.4F + 0.273 AlPO.sub.4 + 0.182 −0.017 Li.sub.3AlF.sub.6 SiF.sub.4 104.08 0.545 LiFePO.sub.4 + 0.455 SiF.sub.4 .fwdarw. 0.182 Fe(PO.sub.3).sub.2 + 0.182 Fe.sub.2PO.sub.4F + −0.044 0.273 Li.sub.2SiF.sub.6 + 0.182 SiO.sub.2 KF 58.1 0.5 LiFePO.sub.4 + 0.5 KF .fwdarw. 0.5 KFePO.sub.4 + 0.5 LiF −0.022 KF.sub.2 77.1 0.1 LiFePO.sub.4 + 0.9 KF.sub.2 .fwdarw. 0.1 K.sub.2LiFeF.sub.6 + 0.1 KPF.sub.6 + 0.6 KF + 0.2 O2 −0.442 KF.sub.3 96.09 0.182 LiFePO.sub.4 + 0.818 KF.sub.3 .fwdarw. 0.182 K.sub.2LiFeF.sub.6 + 0.182 KPF.sub.6 + 0.273 −0.655 KF + 0.364 O.sub.2 CaF.sub.2 78.07 Stable 0.000 ScF.sub.3 101.95 Stable 0.000 TiF.sub.3 104.86 0.44 LiFePO.sub.4 + 0.56 TiF.sub.3 .fwdarw. 0.16 Li2TiF.sub.6 + 0.12 LiTi.sub.2(PO.sub.4).sub.3 + 0.36 −0.061 FeF.sub.2 + 0.16 TiO.sub.2 + 0.08 FeP TiF.sub.4 123.86 0.462 LiFePO.sub.4 + 0.538 TiF.sub.4 .fwdarw. 0.077 Ti4Fe(PO.sub.4).sub.6 + 0.231 Li.sub.2TiF.sub.6 + −0.058 0.385 FeF.sub.2 VF.sub.2 88.94 0.75 LiFePO.sub.4 + 0.25 VF.sub.2 .fwdarw. 0.25 Li.sub.3VFeP.sub.2(O.sub.4F).sub.2 + 0.125 −0.097 Fe.sub.3(PO.sub.4).sub.2 + 0.125 Fe VF.sub.3 107.94 0.75 LiFePO.sub.4 + 0.25 VF.sub.3 .fwdarw. 0.25 Li.sub.3VFeP.sub.2(O.sub.4F).sub.2 + 0.25 Fe.sub.2PO.sub.4F −0.098 VF.sub.4 126.94 0.6 LiFePO.sub.4 + 0.4 VF.sub.4 .fwdarw. 0.2 FePO.sub.4 + 0.2 Li.sub.3VFeP.sub.2(O.sub.4F).sub.2 + 0.2 −0.122 FeF.sub.3 + 0.2 VF.sub.3 VF.sub.5 145.93 0.667 LiFePO.sub.4 + 0.333 VF.sub.5 .fwdarw. 0.222 Li.sub.3VFeP.sub.2(O.sub.4F).sub.2 + 0.037 −0.156 Fe.sub.2P.sub.3(O.sub.3F).sub.3 + 0.111 VPO.sub.5 + 0.37 FeF.sub.3 CrF.sub.2 89.99 0.8 LiFePO.sub.4 + 0.2 CrF.sub.2 .fwdarw. 0.1 Fe(PO.sub.3).sub.2 + 0.1 P.sub.2O.sub.3F.sub.4 + 0.064 −0.502 FeP.sub.4O.sub.11 + 0.036 FeP.sub.4 + 0.2 Li.sub.4CrFe.sub.3O.sub.8 CrF.sub.3 108.99 0.8 LiFePO.sub.4 + 0.2 CrF.sub.3 .fwdarw. 0.15 Fe(PO.sub.3).sub.2 + 0.15 P.sub.2O.sub.3F.sub.4 + 0.023 −0.481 FeP.sub.4O.sub.11 + 0.027 FeP.sub.4 + 0.2 Li.sub.4CrFe.sub.3O.sub.8 CrF.sub.4 127.99 0.752 LiFePO.sub.4 + 0.248 CrF.sub.4 .fwdarw. 0.162 Fe(PO.sub.3).sub.2 + 0.026 FeP.sub.2 + 0.059 −0.551 Cr(PO.sub.3).sub.3 + 0.188 Li.sub.4CrFe.sub.3O.sub.8 + 0.198 PF.sub.5 CrF.sub.5 146.99 0.667 LiFePO.sub.4 + 0.333 CrF.sub.5 .fwdarw. 0.083 Fe.sub.2P.sub.3(O.sub.3F).sub.3 + 0.102 CrF.sub.3 + −0.638 0.065 Cr(PO.sub.3).sub.3 + 0.167 Li.sub.4CrFe.sub.3O.sub.8 + 0.222 PF.sub.5 CrF.sub.6 165.99 0.75 LiFePO.sub.4 + 0.25 CrF.sub.6 .fwdarw. 0.031 P.sub.2O.sub.3F.sub.4 + 0.094 Fe.sub.2P.sub.3(O.sub.3F).sub.3 + −0.692 0.062 Cr(PO.sub.3).sub.3 + 0.187 Li.sub.4CrFe.sub.3O.sub.8 + 0.219 PF.sub.5 MnF.sub.2 92.93 0.5 LiFePO.sub.4 + 0.5 MnF.sub.2 .fwdarw. 0.25 Mn.sub.2PO.sub.4F + 0.25 Fe.sub.2PO.sub.4F + 0.5 LiF −0.014 MnF.sub.3 111.93 0.5 LiFePO.sub.4 + 0.5 MnF.sub.3 .fwdarw. 0.286 FePO.sub.4 + 0.214 Mn.sub.2PO.sub.4F + 0.071 −0.083 LiMnFeF.sub.6 + 0.143 Li.sub.3FeF.sub.6 MnF.sub.4 130.93 0.4 LiFePO.sub.4 + 0.6 MnF.sub.4 .fwdarw. 0.133 Fe.sub.2P.sub.3(O.sub.3F).sub.3 + 0.2 MnO.sub.2 + 0.4 −0.198 LiMnF.sub.4 + 0.133 FeF.sub.3 FeF.sub.2 93.84 0.5 FeF.sub.2 + 0.5 LiFePO.sub.4 .fwdarw. 0.5 Fe.sub.2PO.sub.4F + 0.5 LiF −0.012 FeF.sub.3 112.84 0.4 FeF.sub.3 + 0.6 LiFePO.sub.4 .fwdarw. 0.3 Fe.sub.2PO.sub.4F + 0.3 LiFePO.sub.4F + 0.1 Li.sub.3FeF.sub.6 −0.025 FeF.sub.6 169.84 0.75 FeF.sub.6 + 0.25 LiFePO.sub.4 .fwdarw. 0.25 LiPF.sub.6 + FeF.sub.3 + 0.5 O.sub.2 −0.557 CoF.sub.2 96.93 0.5 LiFePO.sub.4 + 0.5 CoF.sub.2 .fwdarw. 0.5 LiCoPO.sub.4 + 0.5 FeF.sub.2 −0.022 CoF.sub.3 96.93 0.5 LiFePO.sub.4 + 0.5 CoF.sub.3 .fwdarw. 0.167 FePO.sub.4 + 0.167 Li.sub.3FeF.sub.6 + 0.167 −0.137 Co.sub.3(PO.sub.4).sub.2 + 0.167 FeF.sub.3 NiF.sub.2 96.69 0.444 LiFePO.sub.4 + 0.556 NiF.sub.2 .fwdarw. 0.222 Fe.sub.2PO.sub.4F + 0.111 Ni.sub.3(PO.sub.4).sub.2 + −0.010 0.222 Li.sub.2NiF.sub.4 NiF.sub.3 115.69 0.1 LiFePO.sub.4 + 0.9 NiF.sub.3 .fwdarw. 0.1 LiPF.sub.6 + 0.1 FeF.sub.3 + 0.9 NiF.sub.2 + 0.2 O.sub.2 −0.330 CuF.sub.2 101.54 0.382 LiFePO.sub.4 + 0.618 CuF.sub.2 .fwdarw. 0.265 Cu.sub.2PO.sub.4 + 0.029 −0.073 Fe.sub.2Cu(P.sub.2O.sub.7).sub.2 + 0.118 LiFe.sub.2F.sub.6 + 0.088 Li.sub.3FeF.sub.6 + 0.059 CuO ZnF.sub.2 103.39 0.5 ZnF.sub.2 + 0.5 LiFePO.sub.4 .fwdarw. 0.5 LiZnPO.sub.4 + 0.5 FeF.sub.2 −0.048 GaF.sub.3 126.72 0.571 GaF.sub.3 + 0.429 LiFePO4 .fwdarw. 0.143 Li.sub.3GaF.sub.6 + 0.429 GaPO.sub.4 + −0.063 0.429 FeF.sub.2 GeF.sub.2 110.64 0.636 GeF.sub.2 + 0.364 LiFePO.sub.4 .fwdarw. 0.182 Fe.sub.2PO.sub.4F + 0.023 Ge.sub.5P.sub.6O.sub.25 + −0.010 0.023 GeP.sub.2O.sub.7 + 0.182 Li.sub.2GeF.sub.6 + 0.318 Ge Ge.sub.3F.sub.8 369.91 0.556 Ge.sub.3F.sub.8 + 0.444 LiFePO.sub.4 .fwdarw. 0.444 FeF.sub.2 + 0.056 Ge.sub.5P.sub.6O.sub.25 + 1.111 −0.044 GeF.sub.2 + 0.056 GeP.sub.2O.sub.7 + 0.222 Li.sub.2GeF.sub.6 GeF.sub.4 148.63 0.556 GeF.sub.4 + 0.444 LiFePO.sub.4 .fwdarw. 0.444 FeF.sub.2 + 0.056 Ge.sub.5P.sub.6O.sub.25 + 0.056 −0.088 GeP.sub.2O.sub.7 + 0.222 Li.sub.2GeF.sub.6 Ge.sub.5F.sub.12 591.18 0.467 Ge.sub.5F.sub.12 + 0.533 LiFePO.sub.4 .fwdarw. 0.267 Fe.sub.2PO.sub.4F + 0.033 Ge.sub.5P.sub.6O.sub.25 + −0.027 1.867 GeF.sub.2 + 0.033 GeP.sub.2O.sub.7 + 0.267 Li.sub.2GeF.sub.6 RbF 104.47 0.2 LiFePO.sub.4 + 0.8 RbF .fwdarw. 0.133 Rb.sub.3PO.sub.4 + 0.067 Li.sub.3PO.sub.4 + 0.2 −0.007 Rb.sub.2FeF.sub.4 RbF.sub.3 142.46 0.261 LiFePO.sub.4 + 0.739 RbF.sub.3 .fwdarw. 0.043 Rb.sub.2FeF.sub.5 + 0.217 Rb.sub.2LiFeF.sub.6 + −0.495 0.043 LiPF.sub.6 + 0.217 RbP(OF).sub.2 + 0.304 O.sub.2 SrF.sub.2 125.62 Stable 0.000 SrF.sub.3 144.62 0.1 LiFePO.sub.4 + 0.9 SrF.sub.3 .fwdarw. 0.1 SrFeF.sub.5 + 0.1 LiPF.sub.6 + 0.8 SrF.sub.2 + 0.2 O.sub.2 −0.382 YF.sub.3 145.9 0.6 YF.sub.3 + 0.4 LiFePO.sub.4 .fwdarw. 0.2 Fe.sub.2PO.sub.4F + 0.2 YPO.sub.4 + 0.4 LiYF.sub.4 −0.018 ZrF.sub.4 167.22 0.333 LiFePO.sub.4 + 0.667 ZrF.sub.4 .fwdarw. 0.333 ZrFeF.sub.6 + 0.111 LiZr.sub.2(PO.sub.4).sub.3 + −0.041 0.111 Li.sub.2ZrF.sub.6 Nb.sub.2F.sub.5 280.8 0.587 Nb.sub.2F.sub.5 + 0.413 LiFePO.sub.4 .fwdarw. 0.413 FeP + 0.462 NbO.sub.2F + 0.412 −0.167 LiNbF.sub.6 + 0.025 Nb.sub.12O.sub.29 NbF.sub.5 187.9 0.609 NbF.sub.5 + 0.391 LiFePO.sub.4 .fwdarw. 0.043 Nb.sub.2(PO.sub.4).sub.3 + 0.043 −0.078 Nb.sub.3Fe(PO.sub.4).sub.6 + 0.391 LiNbF.sub.6 + 0.348 FeF.sub.2 MoF.sub.3 152.94 0.75 LiFePO.sub.4 + 0.25 MoF.sub.3 .fwdarw. 0.125 Li.sub.3Mo.sub.2(PO.sub.4).sub.3 + 0.375 Fe.sub.2PO.sub.4F + −0.016 0.375 LiF MoF.sub.5 190.93 0.444 LiFePO.sub.4 + 0.556 MoF.sub.5 .fwdarw. 0.148 Mo.sub.2(PO.sub.4).sub.3 + 0.222 Li.sub.2MoF.sub.6 + −0.109 0.444 FeF.sub.3 + 0.037 MoF.sub.3 MoF.sub.6 209.93 0.6 LiFePO.sub.4 + 0.4 MoF.sub.6 .fwdarw. 0.2 Mo.sub.2(PO.sub.4).sub.3 + 0.2 Li.sub.3FeF.sub.6 + 0.4 FeF.sub.3 −0.119 InF.sub.3 171.81 0.5 LiFePO.sub.4 + 0.5 InF.sub.3 .fwdarw. 0.5 InPO.sub.4 + 0.5 LiF + 0.5 FeF.sub.2 −0.022 SnF.sub.2 156.71 0.571 LiFePO.sub.4 + 0.429 SnF.sub.2 .fwdarw. 0.286 Fe.sub.2PO.sub.4F + 0.143 Sn.sub.3(PO.sub.4).sub.2 + −0.013 0.571 LiF SnF.sub.3 175.71 0.438 LiFePO.sub.4 + 0.562 SnF.sub.3 .fwdarw. 0.219 Fe.sub.2PO.sub.4F + 0.094 Sn.sub.3PO.sub.4F.sub.3 + −0.024 0.042 LiSn.sub.2(PO.sub.4).sub.3 + 0.198 Li.sub.2SnF.sub.6 SnF.sub.4 194.7 0.4 LiFePO.sub.4 + 0.6 SnF.sub.4 .fwdarw. 0.4 FeF.sub.2 + 0.4 SnPO.sub.4F + 0.2 Li.sub.2SnF.sub.6 −0.101 Sn.sub.3F.sub.8 508.12 0.64 LiFePO.sub.4 + 0.36 Sn.sub.3F.sub.8 .fwdarw. 0.32 Fe.sub.2PO.sub.4F + 0.24 Sn.sub.3PO.sub.4F.sub.3 + 0.027 −0.020 LiSn.sub.2(PO.sub.4).sub.3 + 0.307 Li.sub.2SnF.sub.6 Sb.sub.2F.sub.13 490.5 0.5 LiFePO.sub.4 + 0.5 Sb.sub.2F.sub.13 .fwdarw. 0.167 SbPO.sub.5 + 0.333 SbP(OF.sub.3).sub.2 + 0.5 −0.335 FeF.sub.3 + 0.5 LiSbF.sub.6 + 0.25 O.sub.2 Sb.sub.2F.sub.7 376.51 0.333 LiFePO.sub.4 + 0.667 Sb.sub.2F.sub.7 .fwdarw. 0.333 SbPO.sub.4 + 0.333 FeF.sub.2 + 0.333 −0.030 LiSbF.sub.6 + 0.667 SbF.sub.3 SbF.sub.4 197.75 0.261 LiFePO.sub.4 + 0.739 SbF.sub.4 .fwdarw. 0.022 Fe(SbO.sub.3).sub.2 + 0.065 Fe.sub.3(P.sub.2O.sub.7).sub.2 + −0.055 0.043 FeF.sub.2 + 0.261 LiSbF.sub.6 + 0.435 SbF.sub.3 SbF.sub.6 235.75 0.333 LiFePO.sub.4 + 0.667 SbF.sub.6 .fwdarw. 0.167 SbPO.sub.5 + 0.167 SbP(OF.sub.3).sub.2 + −0.323 0.333 FeF.sub.3 + 0.333 LiSbF.sub.6 + 0.083 O.sub.2 SbF.sub.3 178.76 0.667 LiFePO.sub.4 + 0.333 SbF.sub.3 .fwdarw. 0.333 SbPO.sub.4 + 0.333 Fe.sub.2PO.sub.4F + −0.014 0.667 LiF Sb.sub.7F.sub.29 1403.27 0.727 LiFePO.sub.4 + 0.273 Sb.sub.7F.sub.29 .fwdarw. 0.061 Fe(SbO.sub.3).sub.2 + 0.182 −0.066 Fe.sub.3(P.sub.2O.sub.7).sub.2 + 0.121 FeF.sub.3 + 0.727 LiSbF.sub.6 + 1.061 SbF.sub.3 Sb.sub.11F.sub.43 2156.29 0.779 LiFePO.sub.4 + 0.221 Sb.sub.11F.sub.43 .fwdarw. 0.065 Fe(SbO.sub.3).sub.2 + 0.195 −0.052 Fe.sub.3(P.sub.2O.sub.7).sub.2 + 0.13 FeF.sub.2 + 0.779 LiSbF.sub.6 + 1.519 SbF.sub.3 CsF 151.9 0.211 LiFePO.sub.4 + 0.789 CsF .fwdarw. 0.07 Li.sub.3PO.sub.4 + 0.053 Cs.sub.7Fe.sub.4F.sub.15 + 0.14 −0.003 Cs.sub.3PO.sub.4 BaF.sub.2 175.32 Stable 0.000 BaF.sub.3 194.32 0.1 LiFePO.sub.4 + 0.9 BaF.sub.3 .fwdarw. 0.1 LiPF.sub.6 + 0.8 BaF.sub.2 + 0.1 BaFeF.sub.5 + 0.2 −0.356 O.sub.2 LaF.sub.3 195.9 Stable 0.000 CeF.sub.3 197.11 0.333 CeF.sub.3 + 0.667 LiFePO.sub.4 .fwdarw. 0.333 Fe.sub.2PO.sub.4F + 0.333 CePO.sub.4 + −0.004 0.667 LiF CeF.sub.4 216.11 0.579 CeF.sub.4 + 0.421 LiFePO.sub.4 .fwdarw. 0.421 LiCeF.sub.5 + 0.211 Fe.sub.2PO.sub.4F + −0.010 0.053 CeO.sub.2 + 0.105 CeP.sub.2O.sub.7 NdF.sub.3 201.24 Stable 0.000 HfF.sub.4 254.48 0.571 LiFePO.sub.4 + 0.429 HfF.sub.4 .fwdarw. 0.571 FeF.sub.2 + 0.143 HfP.sub.2O.sub.7 + 0.143 −0.025 Hf.sub.2P.sub.2O.sub.9 + 0.571 LiF TaF.sub.5 275.94 0.4 LiFePO.sub.4 + 0.6 TaF.sub.5 .fwdarw. 0.1 Fe(PO.sub.3).sub.2 + 0.2 TaPO.sub.5 + 0.4 LiTaF.sub.6 + −0.089 0.3 FeF.sub.2 WF.sub.4 259.83 0.5 WF.sub.4 + 0.5 LiFePO.sub.4 .fwdarw. 0.5 PWO.sub.4F + 0.5 FeF.sub.2 + 0.5 LiF −0.118 WF.sub.6 297.83 0.333 WF.sub.6 + 0.667 LiFePO.sub.4 .fwdarw. 0.111 FeP.sub.6(WO.sub.8).sub.3 + 0.222 Li.sub.3FeF.sub.6 + −0.066 0.333 FeF.sub.2 BiF.sub.3 265.98 0.4 LiFePO.sub.4 + 0.6 BiF.sub.3 .fwdarw. 0.2 BiPO.sub.4 + 0.4 LiBiF.sub.4 + 0.2 Fe.sub.2PO.sub.4F −0.019 BiF.sub.5 303.97 0.182 LiFePO.sub.4 + 0.818 BiF.sub.5 .fwdarw. 0.182 LiPF.sub.6 + 0.818 BiF.sub.3 + 0.182 −0.296 FeF.sub.3 + 0.364 O.sub.2

    [0063] Each MF.sub.x compound was further evaluated in comparison with AlF.sub.3 for stability when in contact with LiFePO.sub.4, as illustrated in Table 2. It is desirable for a new metal fluoride coating to have a more stable interface with LiFePO.sub.4 cathode materials. For example, AlF.sub.3:LiFePO.sub.4 is 0.455:0.545=0.83. It is beneficial when the “Ratio” between the metal fluorides to LiFePO.sub.4 is low—for example, VF.sub.2:LiFePO.sub.4=0.33 which is lower than the AlF.sub.3 to LiFePO.sub.4 ratio (0.83). LiF, MgF.sub.2, CaF.sub.2, ScF.sub.3, SrF.sub.2, BaF.sub.2, LaF.sub.3, and NdF.sub.3 do not react at all with LiFePO.sub.4 cathode materials; this means that when these compounds are in contact with LiFePO.sub.4, neither the compound nor the LiFePO.sub.4 cathode material will undergo decomposition reactions. All other metal fluoride materials vs. AlF.sub.3 (“Ratio vs. AlF.sub.3”) are shown in the next column in Table 2, where it is beneficial when this value is less than 1 (i.e., less reactive against LiFePO.sub.4). For example, ratio score for VF.sub.2 is 0.33/0.83=0.40. Another key criterion is the reaction enthalpy (“E.sub.rxn”), where for the AlF.sub.3 reaction with LiFePO.sub.4 the E.sub.rxn=−0.017 eV/atom. All metal fluoride materials are compared vs. AlF.sub.3 in the “E.sub.rxn vs. AlF.sub.3,” where it is beneficial when this value is less than 1 (i.e., interfacial reaction between LiFePO.sub.4 and metal fluoride is rather unfavorable and less favorable than for AlF.sub.3). For example, NaF has E.sub.rxn value of −0.009 eV/atom and therefore “E.sub.rxn vs. AlF.sub.3,” for NaF is −0.009/−0.017=0.53. The next column, “Sum” adds the two values that are referenced to AlF.sub.3 for molar ratio and reaction enthalpy. Since these values are evaluated based on the molar fraction, these values are converted to by dividing my molecular weight in the “per mg” column: e.g., 2.00/83.98×1,000=23.8 for AlF.sub.3. Lastly, the “LiFePO.sub.4 stability score” provides the percentage improvement vs. AlF.sub.3 for all materials (e.g., 23.8/21.8×100=109.5% for MnF.sub.2).

    [0064] Using the above-described assessment better or comparable coating materials for a LiFePO.sub.4 cathode can be determined as compared with AlF.sub.3. As illustrated in Table 2, LiF, MgF.sub.2, CaF.sub.2, ScF.sub.3, SrF.sub.2, BaF.sub.2, LaF.sub.3, and NdF.sub.3 do not react at all with LiFePO.sub.4 cathode materials, i.e., ideal for a coating material. In addition, Ge.sub.3F.sub.8, Ge.sub.5F.sub.12, MoF.sub.3, InF.sub.3, SnF.sub.2, SnF.sub.3, Sn.sub.3F.sub.8, Sb.sub.2F.sub.7, SbF.sub.3, Sb.sub.7F.sub.29, Sb.sub.11F.sub.43, CeF.sub.3, CeF.sub.4, HfF.sub.4, WF.sub.6, and BiF.sub.3 are better coating candidates than AlF.sub.3 (i.e., at least 25% more protective per the “LiFePO.sub.4 stability score”), and MnF.sub.2, FeF.sub.2, NiF.sub.2, and YF.sub.3 are comparable to AlF.sub.3, i.e., greater than 100% but less than 125% per the “LiFePO.sub.4 stability score”).

    TABLE-US-00002 TABLE 2 LiFePO.sub.4 stability LiFePO.sub.4 Ratio Ratio vs. E.sub.rxn E.sub.rxn vs. stability score MF.sub.X (MF.sub.X:LiFePO.sub.4) AIF.sub.3 (eV/atom) AIF.sub.3 Sum per mg (%) LiF 0.00 0.00 0.000 0.00 0.00 0.0 Best (Does not react) (Infinite) NaF 2.00 2.40 −0.009 0.53 2.93 69.7 34.2 MgF.sub.2 0.00 0.00 0.000 0.00 0.00 0.0 Best (Does not react) (Infinite) AlF.sub.3 0.83 1.00 −0.017 1.00 2.00 23.8 100.0 SiF.sub.4 0.83 1.00 −0.044 2.59 3.59 34.5 69.1 KF 1.00 1.20 −0.022 1.29 2.49 42.9 55.5 KF.sub.2 9.00 10.78 −0.442 26.00 36.78 477.0 5.0 KF.sub.3 4.49 5.38 −0.655 38.53 43.91 457.0 5.2 CaF.sub.2 0.00 0.00 0.000 0.00 0.00 0.0 Best (Does not react) (Infinite) ScF.sub.3 0.00 0.00 0.000 0.00 0.00 0.0 Best (Does not react) (Infinite) TiF.sub.3 1.27 1.52 −0.061 3.59 5.11 48.8 48.8 TiF.sub.4 1.16 1.39 −0.058 3.41 4.81 38.8 61.4 VF.sub.2 0.33 0.40 −0.097 5.71 6.11 68.6 34.7 VF.sub.3 0.33 0.40 −0.098 5.76 6.16 57.1 41.7 VF.sub.4 0.67 0.80 −0.122 7.18 7.98 62.8 37.9 VF.sub.5 0.50 0.60 −0.156 9.18 9.78 67.0 35.6 CrF.sub.2 0.25 0.30 −0.502 29.53 29.83 331.5 7.2 CrF.sub.3 0.25 0.30 −0.481 28.29 28.59 262.4 9.1 CrF.sub.4 0.33 0.40 −0.551 32.41 32.81 256.3 9.3 CrF.sub.5 0.50 0.60 −0.638 37.53 38.13 259.4 9.2 CrF.sub.6 0.33 0.40 −0.692 40.71 41.11 247.6 9.6 MnF.sub.2 1.00 1.20 −0.014 0.82 2.02 21.8 109.5 MnF.sub.3 1.00 1.20 −0.083 4.88 6.08 54.3 43.8 MnF.sub.4 1.50 1.80 −0.198 11.65 13.44 102.7 23.2 FeF.sub.2 1.00 1.20 −0.012 0.71 1.90 20.3 117.4 FeF.sub.3 1.50 1.80 −0.025 1.47 3.27 29.0 82.2 FeF.sub.6 0.33 0.40 −0.557 32.76 33.16 195.3 12.2 CoF.sub.2 1.00 1.20 −0.022 1.29 2.49 25.7 92.6 CoF.sub.3 1.00 1.20 −0.137 8.06 9.26 95.5 24.9 NiF.sub.2 1.25 1.50 −0.010 0.59 2.09 21.6 110.3 NiF.sub.3 9.00 10.78 −0.330 19.41 30.19 261.0 9.1 CuF.sub.2 1.62 1.94 −0.073 4.29 6.23 61.4 38.8 ZnF.sub.2 1.00 1.20 −0.048 2.82 4.02 38.9 61.2 GaF.sub.3 1.33 1.59 −0.063 3.71 5.30 41.8 56.9 GeF.sub.2 1.75 2.09 −0.010 0.59 2.68 24.2 98.3 Ge.sub.3F.sub.8 0.80 0.96 −0.044 2.59 3.54 9.6 248.5 GeF.sub.4 0.80 0.96 −0.088 5.18 6.13 41.3 57.7 Ge.sub.5F.sub.12 0.88 1.05 −0.027 1.59 2.64 4.5 533.8 RbF 4.00 4.79 −0.007 0.41 5.20 49.8 47.8 RbF.sub.3 2.83 3.39 −0.495 29.12 32.51 228.2 10.4 SrF.sub.2 0.00 0.00 0.000 0.00 0.00 0.0 Best (Does not react) (Infinite) SrF.sub.3 9.00 10.78 −0.382 22.47 33.25 229.9 10.4 YF.sub.3 1.50 1.80 −0.018 1.06 2.86 19.6 121.7 ZrF.sub.4 2.00 2.40 −0.041 2.41 4.81 28.8 82.8 Nb.sub.2F.sub.5 1.42 1.70 −0.167 9.82 11.53 41.0 58.0 NbF.sub.5 1.56 1.87 −0.078 4.59 6.45 34.3 69.3 MoF.sub.3 0.33 0.40 −0.016 0.94 1.34 8.8 271.7 MoF.sub.5 1.25 1.50 −0.109 6.41 7.91 41.4 57.5 MoF.sub.6 0.67 0.80 −0.119 7.00 7.80 37.1 64.1 InF.sub.3 1.00 1.20 −0.022 1.29 2.49 14.5 164.2 SnF.sub.2 0.75 0.90 −0.013 0.76 1.66 10.6 224.2 SnF.sub.3 1.28 1.54 −0.024 1.41 2.95 16.8 141.9 SnF.sub.4 1.50 1.80 −0.101 5.94 7.74 39.7 59.9 Sn.sub.3F.sub.8 0.56 0.67 −0.020 1.18 1.85 3.6 654.0 Sb.sub.2F.sub.13 1.00 1.20 −0.335 19.71 20.90 42.6 55.9 Sb.sub.2F.sub.7 2.00 2.40 −0.030 1.76 4.16 11.0 215.5 SbF.sub.4 2.83 3.39 −0.055 3.24 6.63 33.5 71.1 SbF.sub.6 2.00 2.40 −0.323 19.00 21.40 90.8 26.2 SbF.sub.3 0.50 0.60 −0.014 0.82 1.42 8.0 299.3 Sb.sub.7F.sub.29 0.38 0.45 −0.066 3.88 4.33 3.1 771.4 Sb.sub.11F.sub.43 0.28 0.34 −0.052 3.06 3.40 1.6 1511.0 CsF 3.74 4.48 −0.003 0.18 4.66 30.6 77.7 BaF.sub.2 0.00 0.00 0.000 0.00 0.00 0.0 Best (Does not react) (Infinite) BaF.sub.3 9.00 10.78 −0.356 20.94 31.72 163.2 14.6 LaF.sub.3 0.00 0.00 0.000 0.00 0.00 0.0 Best (Does not react) (Infinite) CeF.sub.3 0.50 0.60 −0.004 0.24 0.83 4.2 563.3 CeF.sub.4 0.73 0.87 −0.010 0.59 1.46 6.8 352.7 NdF.sub.3 0.00 0.00 0.000 0.00 0.00 0.0 Best (Does not react) (Infinite) HfF.sub.4 0.75 0.90 −0.025 1.47 2.37 9.3 255.7 TaF.sub.5 1.50 1.80 −0.089 5.24 7.03 25.5 93.5 WF.sub.4 1.00 1.20 −0.118 6.94 8.14 31.3 76.0 WF.sub.6 0.50 0.60 −0.066 3.88 4.48 15.0 158.3 BiF.sub.3 1.50 1.80 −0.019 1.12 2.91 11.0 217.4 BiF.sub.5 4.49 5.38 −0.296 17.41 22.80 75.0 31.8

    [0065] In a similar fashion as described for LiFePO.sub.4, reactivity between the MF.sub.x and H.sub.2O was assessed. The results are illustrated in Table 3, thus identifying metal fluorides that are more protective against H.sub.2O: LiF, MgF.sub.2, AlF.sub.3, CaF.sub.2, ScF.sub.3, MnF.sub.2, FeF.sub.2, NiF.sub.2, SrF.sub.2, YF.sub.3, MoF.sub.3, InF.sub.3, SnF.sub.2, SnF.sub.3, Sn.sub.3F.sub.8, SbF.sub.3, BaF.sub.2, LaF.sub.3, CeF.sub.3, CeF.sub.4, NdF.sub.3, and BiF.sub.3 do not react with H.sub.2O; Ge.sub.3F.sub.8, Ge.sub.5F.sub.12, Sb.sub.2F.sub.7, Sb.sub.7F.sub.29, Sb.sub.11F.sub.43, HfF.sub.4, and WF.sub.6 have a decomposition reaction with H.sub.2O.

    TABLE-US-00003 TABLE 3 H.sub.2O stability MF.sub.x H.sub.2O Stability LiF Stable (does not react with H.sub.2O) MgF.sub.2 AlF.sub.3 CaF.sub.2 ScF.sub.3 MnF.sub.2 FeF.sub.2 NiF.sub.2 SrF.sub.2 YF.sub.3 MoF.sub.3 InF.sub.3 SnF.sub.2 SnF.sub.3 Sn.sub.3F.sub.8 SbF.sub.3 BaF.sub.2 LaF.sub.3 CeF.sub.3 CeF.sub.4 NdF.sub.3 BiF.sub.3 Ge.sub.3F.sub.8 0.25 Ge.sub.3F.sub.8 + 0.75 H.sub.2O .fwdarw. 0.125 Ge.sub.5F.sub.12 + 0.5 H.sub.3OF + 0.125 GeO.sub.2 Ge.sub.5F.sub.12 0.143 Ge.sub.5F.sub.12 + 0.857 H.sub.2O .fwdarw. 0.571 GeF.sub.2 + 0.571 H.sub.3OF + 0.143 GeO.sub.2 Sb.sub.2F.sub.7 0.526 H.sub.2O + 0.474 Sb.sub.2F.sub.7 .fwdarw. 0.211 SbH.sub.5(OF.sub.3).sub.2 + 0.684 SbF.sub.3 + 0.053 SbO.sub.2 Sb.sub.7F.sub.29 0.899 H.sub.2O + 0.101 Sb.sub.7F.sub.29 .fwdarw. 0.36 SbH.sub.5(OF.sub.3).sub.2 + 0.258 SbF.sub.3 + 0.09 SbO.sub.2 Sb.sub.11F.sub.43 0.917 H.sub.2O + 0.083 Sb.sub.11F.sub.43 .fwdarw. 0.367 SbH.sub.5(OF.sub.3).sub.2 + 0.45 SbF.sub.3 + 0.092 SbO.sub.2 HfF.sub.4 0.75 H.sub.2O + 0.25 HfF.sub.4 .fwdarw. 0.25 HfH.sub.6O.sub.3F.sub.4 WF.sub.6 0.1 WF.sub.6 + 0.9 H.sub.2O .fwdarw. 0.1 WO.sub.3 + 0.6 H.sub.3OF

    [0066] HF can form in the liquid electrolyte when residual water/moisture is present to react with LiPF.sub.6 salt in the battery cell: LiPF.sub.6+H.sub.2O.Math.POF.sub.3+2HF+LiF. HF is an acid that can degrade subcomponents in battery cell. In particular, LiFePO.sub.4 can react with HF in the reactions illustrated in Table 4. Table 4 illustrates that in all ratios between HF and LiFePO.sub.4, LiFePO.sub.4 cathode material will decompose to another species; therefore, cathode materials will be lost along with their capacity to (de-)insert Li.sup.+ ions.

    TABLE-US-00004 TABLE 4 HF-mediated decomposition reactions of LiFePO.sub.4. Molar fraction E.sub.rxn HF Chemical reactions (eV/atom) 0.000 HF .fwdarw. HF 0.000 0.040 0.04 LiFePO.sub.4 + 0.96 HF .fwdarw. 0.04 LiPF.sub.6 + 0.16 H.sub.6OF.sub.4 + 0.04 −0.138 FeF.sub.2 0.059 0.059 LiFePO.sub.4 + 0.941 HF .fwdarw. 0.235 H.sub.4OF.sub.2 + 0.059 LiPF.sub.6 + −0.149 0.059 FeF.sub.2 0.077 0.077 LiFePO.sub.4 + 0.923 HF .fwdarw. 0.308 H.sub.3OF + 0.077 LiPF.sub.6 + −0.156 0.077 FeF.sub.2 0.200 0.2 LiFePO.sub.4 + 0.8 HF .fwdarw. 0.2 LiHF.sub.2 + 0.2 PH.sub.3O.sub.4 + 0.2 FeF.sub.2 −0.137 0.333 0.333 LiFePO.sub.4 + 0.667 HF .fwdarw. 0.333 LiP(HO.sub.2).sub.2 + 0.333 FeF.sub.2 −0.109 0.500 0.5 LiFePO.sub.4 + 0.5 HF .fwdarw. 0.25 LiP(HO.sub.2).sub.2 + 0.25 Fe.sub.2PO.sub.4F + −0.074 0.25 LiF 1.000 LiFePO.sub.4 .fwdarw. LiFePO.sub.4 0.000

    [0067] Typically, oxide or PO.sub.4-based coatings will be chemically converted to a fluoride-containing compound by scavenging HF where such converted materials may form a stable cathode solid electrolyte interface (“c-SEI”). However, for hydrophobic coating materials for cathode materials such as LiFePO.sub.4, materials that are stable against HF (i.e., providing a physical barrier by use as a coating) are more desirable than chemical scavengers. The HF reactivity was therefore determined for identified MF.sub.x compounds and the results shown in Table 5. LiF, CaF.sub.2, SnF.sub.2, Sn.sub.3F.sub.8, SbF.sub.3, and BaF.sub.2 were found to be reactive with HF.

    TABLE-US-00005 TABLE 5 HF stability. MF.sub.x HF Reaction Ratio E.sub.rxn LiF 0.5 HF + 0.5 LiF .fwdarw. 0.5 LiHF.sub.2 1.00 −0.110 MgF.sub.2 Stable 0.00 0.000 AlF.sub.3 Stable 0.00 0.000 CaF.sub.2 0.333 CaF.sub.2 + 0.667 HF .fwdarw. 0.333 CaH.sub.2F.sub.4 2.00 −0.099 ScF.sub.3 Stable 0.00 0.000 MnF.sub.2 Stable 0.00 0.000 FeF.sub.2 Stable 0.00 0.000 NiF.sub.2 Stable 0.00 0.000 SrF.sub.2 Stable 0.00 0.000 YF.sub.3 Stable 0.00 0.000 MoF.sub.3 Stable 0.00 0.000 InF.sub.3 Stable 0.00 0.000 SnF.sub.2 0.25 SnF.sub.2 + 0.75 HF .fwdarw. 0.25 SnF.sub.3 + 0.25 H.sub.3F.sub.2 3.00 −0.021 SnF.sub.3 Stable 0.00 0.000 Sn.sub.3F.sub.8 0.25 Sn.sub.3F.sub.8 + 0.75 HF .fwdarw. 0.75 SnF.sub.3 + 0.25 3.00 −0.008 H.sub.3F.sub.2 SbF.sub.3 0.929 HF + 0.071 SbF.sub.3 .fwdarw. 0.071 SbH.sub.7F.sub.12 + 0.08 −0.005 0.143 H.sub.3F.sub.2 BaF.sub.2 0.143 BaF.sub.2 + 0.857 HF .fwdarw. 0.143 BaH.sub.6F.sub.8 5.99 −0.142 LaF.sub.3 Stable 0.00 0.000 CeF.sub.3 Stable 0.00 0.000 CeF.sub.4 Stable 0.00 0.000 NdF.sub.3 Stable 0.00 0.000 BiF.sub.3 Stable 0.00 0.000

    [0068] PF.sub.5.sup.− is a species that forms from LiPF.sub.6 salt decomposition: LiPF.sub.6.Math.LiF+PF.sub.5.sup.−. Similar to HF, PF.sub.5.sup.− will decompose battery subcomponents such as LiFePO.sub.4 (see Table 6). Thus, similar to the determination of HF reactivity, the PF.sub.5.sup.− reactivity for MO(OH) candidates was determined, where an ideal MF.sub.x coating should act as a physical barrier against PF.sub.5.sup.−. As illustrated in Table 7, all MF.sub.x compounds that were stable against HF were found to be stable against PF.sub.5.

    TABLE-US-00006 TABLE 6 PF.sub.5.sup.− decomposition reactions of LiFePO.sub.4. Molar Fraction E.sub.rxn LiFePO.sub.4 PF.sub.5.sup.− reactions [eV/atom] 0.000 PF.sub.5 .fwdarw. PF.sub.5 0.000 0.429 0.429 LiFePO.sub.4 + 0.571 PF.sub.5 .fwdarw. 0.286 Fe(PO.sub.3).sub.2 + 0.143 FeF.sub.2 + 0.429 −0.067 LiPF.sub.6 0.750 0.75 LiFePO.sub.4 + 0.25 PF.sub.5 .fwdarw. 0.5 Fe(PO.sub.3).sub.2 + 0.25 FeF.sub.2 + 0.75 LiF −0.061 0.800 0.8 LiFePO.sub.4 + 0.2 PF.sub.5 .fwdarw. 0.4 Fe(PO.sub.3).sub.2 + 0.2 Fe.sub.2PO.sub.4F + 0.8 LiF −0.052 0.857 0.857 LiFePO.sub.4 + 0.143 PF.sub.5 .fwdarw. 0.429 Fe.sub.2PO.sub.4F + 0.571 LiPO.sub.3 + 0.286 −0.041 LiF 0.909 0.909 LiFePO.sub.4 + 0.091 PF.sub.5 .fwdarw. 0.273 Fe.sub.2PO.sub.4F + 0.364 Li.sub.2FeP.sub.2O.sub.7 + −0.028 0.182 LiF 1.000 LiFePO.sub.4 .fwdarw. LiFePO.sub.4 0.000

    TABLE-US-00007 TABLE 7 PF.sub.5 reactions with MF.sub.x coating candidates. PF.sub.5 MF.sub.x Stability MgF.sub.2, AlF.sub.3, ScF.sub.3, MnF.sub.2, Stable FeF.sub.2, NiF.sub.2, SrF.sub.2, YF.sub.3, MoF.sub.3, InF.sub.3, SnF.sub.3, LaF.sub.3, CeF.sub.3, CeF.sub.4, NdF.sub.3, BiF.sub.3

    [0069] Electrolyte decomposition leads to the formation of the desirable solid electrolyte interface (SEI). The SEI is primarily composed of LiF, Li.sub.2O, Li.sub.2CO.sub.3 and other insoluble products. Enriching the SEI with LiF has recently gained popularity to improve Li cyclability. Here, it is desirable that the coatings not to consume LiF, so that it remains available for the SEI formation. Similar to the determination of HF reactivity and PF.sub.5.sup.− reactivity discussed above, the LiF reactivity for MF.sub.x compounds was determined and the results are provided in Table 8. As illustrated in Table 8, 0.25 AlF.sub.3 reacts with 0.75 LiF to form 0.25 Li.sub.3AlF.sub.6 whereas MgF.sub.2, MnF.sub.2, FeF.sub.2, SrF.sub.2, MoF.sub.3, LaF.sub.3, CeF.sub.3, and NdF.sub.3 are stable when in contact with LiF. Thus, as used herein and in the claims, MgF.sub.2, MnF.sub.2, FeF.sub.2, SrF.sub.2, MoF.sub.3, LaF.sub.3, CeF.sub.3, and NdF.sub.3 have a greater “LiF score” than AlF.sub.3.

    TABLE-US-00008 TABLE 8 LiF reactions with MF.sub.x compounds. MF.sub.x LiF Reaction MgF.sub.2 Stable AlF.sub.3 0.75 LiF + 0.25 AlF.sub.3 .fwdarw. 0.25 Li.sub.3AlF.sub.6 ScF.sub.3 0.25 ScF.sub.3 + 0.75 LiF .fwdarw. 0.25 Li.sub.3ScF.sub.6 MnF.sub.2 Stable FeF.sub.2 Stable NiF.sub.2 0.667 LiF + 0.333 NiF.sub.2 .fwdarw. 0.333 Li.sub.2NiF.sub.4 SrF.sub.2 Stable YF.sub.3 0.5 YF.sub.3 + 0.5 LiF .fwdarw. 0.5 LiYF.sub.4 MoF.sub.3 Stable InF.sub.3 0.5 LiF + 0.5 InF.sub.3 .fwdarw. 0.5 LiInF.sub.4 SnF.sub.3 0.5 SnF.sub.3 + 0.5 LiF .fwdarw. 0.25 Li.sub.2SnF.sub.6 + 0.25 SnF.sub.2 LaF.sub.3 Stable CeF.sub.3 Stable CeF.sub.4 0.5 CeF.sub.4 + 0.5 LiF .fwdarw. 0.5 LiCeF.sub.5 NdF.sub.3 Stable BiF.sub.3 0.5 BiF.sub.3 + 0.5 LiF .fwdarw. 0.5 LiBiF.sub.4

    [0070] LiOH may also be present at the surface of cathode materials, depending on the choice of Li salt precursors. The presence of LiOH leads to the formation of H.sub.2O within the cell, and this can subsequently form HF. For most LiFePO.sub.4, LiOH may be included as a Li.sup.+ salt because Li.sub.2CO.sub.3 typically does not fully decompose in the temperature range in which LiFePO.sub.4 is synthesized. For example, LiFePO.sub.4 reacts with LiOH according to following reaction with a E.sub.rxn of −0.054 eV/atom: 0.333 LiFePO.sub.4+0.667 LiOH.fwdarw.0.333 FeO+0.333 Li.sub.3PO.sub.4+0.333 H.sub.2O. Similar to LiF, it is desirable that the LiOH reaction not take place when in contact with the MF.sub.x compounds in order to avoid H.sub.2O formation. Thus, similar to the determination of LiFePO.sub.4 stability, FH reactivity, and PF.sub.5.sup.− reactivity discussed above, the LiOH reactivity for MF.sub.x compounds was determined then normalized to the case of FeF.sub.2 (as AlF.sub.3 was determined to not be stable to LiF, as discussed above) to ultimately provide a “LiOH score,” as indicated in Table 9. As shown in Table 9, SrF.sub.2 is stable against LiOH, LaF.sub.3 and NdF.sub.3 are each significantly more stable than FeF.sub.2, and MgF.sub.2, MnF.sub.2, and MoF.sub.3 have comparable LiOH stability as FeF.sub.2 (89.5 to 106.8% vs. FeF.sub.2); CeF.sub.3 was determined to release H.sub.2 gas as byproduct.

    TABLE-US-00009 TABLE 9 LiOH stability for certain MF.sub.x compounds. Ratio vs. E.sub.rxn vs. per LiOH MF.sub.x LiOH Reaction Ratio FeF.sub.2 E.sub.rxn FeF.sub.2 Sum mg score MgF.sub.2 0.333 MgF.sub.2 + 0.667 LiHO .fwdarw. 0.333 2.00 1.00 −0.050 0.49 1.49 23.84 89.4 Mg(HO).sub.2 + 0.667 LiF MnF.sub.2 0.667 LiHO + 0.333 MnF.sub.2 .fwdarw. 0.333 2.00 1.00 −0.088 0.85 1.85 19.95 106.8 MnO + 0.333 H.sub.2O + 0.667 LiF FeF.sub.2 0.333 FeF.sub.2 + 0.667 LiHO .fwdarw. 0.333 2.00 1.00 −0.103 1.00 2.00 21.31 100.0 FeO + 0.333 H.sub.2O + 0.667 LiF SrF.sub.2 Stable 0.00 0.00 0.000 0.00 0.00 0.00 Best (Infinite) MoF.sub.3 0.75 LiHO + 0.25 MoF.sub.3 .fwdarw. 0.187 3.00 1.50 −0.161 1.56 3.06 20.03 106.4 MoO.sub.2 + 0.375 H.sub.2O + 0.75 LiF + 0.063 Mo LaF.sub.3 0.667 LiHO + 0.333 LaF.sub.3 .fwdarw. 0.333 0.50 0.25 −0.054 0.52 0.77 3.95 539.2 H.sub.2O + 0.333 LaOF + 0.667 LiF CeF.sub.3 0.25 CeF.sub.3 + 0.75 LiHO .fwdarw. 0.3 H.sub.2O + 3.00 1.50 −0.097 0.94 2.44 12.39 172.0 0.75 LiF + 0.05 Ce.sub.5O.sub.9 + 0.075 H.sub.2 NdF.sub.3 0.75 LiHO + 0.25 NdF.sub.3 .fwdarw. 0.25 3.00 1.5 −0.029 0.28 1.78 8.85 240.7 Nd(HO).sub.3 + 0.75 LiF

    [0071] Preliminarily identified ternary Li-M-F compounds are shown in Table 10 below along with the associated molecular weight and bandgap (“E.sub.g”), where several are from Table 8 (where certain MF.sub.x compounds reacted with LiF to form a ternary Li-M-F compounds) and others are based on compositional search extending binary metal fluorides that are found to be top candidates.

    TABLE-US-00010 TABLE 10 Li—M—F compounds for further screening as LiFePO.sub.4 coating candidates. Li—M—F E.sub.g Compound MW (eV) Li.sub.3AlF.sub.6 161.79 7.690 Li.sub.3ScF.sub.6 179.77 6.616 Li.sub.2NiF.sub.4 148.57 5.086 LiYF.sub.4 171.84 7.837 LiInF.sub.4 197.75 4.023 Li.sub.2SnF.sub.6 246.58 5.009 LiCeF.sub.5 242.05 2.276 LiBiF.sub.4 291.92 4.877 LiMnF.sub.4 137.87 1.852 LiMnF.sub.6 175.87 0.000 Li.sub.2MnF.sub.5 163.81 1.843 Li.sub.2MnF.sub.6 182.81 2.684 Li.sub.2FeF.sub.6 183.72 0.313 LiFe.sub.2F.sub.6 232.62 1.887 LiFeF.sub.6 176.78 1.257 Li.sub.3FeF.sub.6 190.66 3.984 Li.sub.2MoF.sub.6 223.81 2.274

    [0072] Similar to the assessment for MF.sub.x compounds, each Li-M-F compound was further evaluated in comparison with AlF.sub.3 for stability when in contact with LiFePO.sub.4, as illustrated in Table 11. As illustrated by the “LiFePO.sub.4 stability score” in Table 11, 11 out of 17 Li-M-F compounds had a greater “LiFePO.sub.4 stability score” than AlF.sub.3. These 11 Li-M-F compounds were further assessed for reactivity with H.sub.2O and found not to react with H.sub.2O.

    TABLE-US-00011 TABLE 11 LiFePO.sub.4 stability with certain Li—M—F compounds. LiFePO.sub.4 Li—M—F Ratio Ratio vs. E.sub.rxn E.sub.rxn vs. per stability score Compound LiFePO.sub.4 Reaction (Li—M—F:LiFePO4) AlF.sub.3 (eV/atom) AlF.sub.3 Sum mg (%) Li.sub.3AlF.sub.6 Stable 0.00 0.00 0.000 0.00 0.00 0.00 Best (Infinite) Li.sub.3ScF.sub.6 Stable 0.00 0.00 0.000 0.00 0.00 0.00 Best (Infinite) Li.sub.2NiF.sub.4 0.333 Li.sub.2NiF.sub.4 + 0.667 0.50 0.60 −0.004 0.24 0.83 5.61 424.1 LiFePO.sub.4 .fwdarw. 0.333 LiNiPO.sub.4 + 0.333 Fe.sub.2PO.sub.4F + LiF LiYF.sub.4 Stable 0.00 0.00 0.000 0.00 0.00 0.00 Best (Infinite) LiInF.sub.4 0.667 LiFePO.sub.4 + 0.333 0.50 0.60 −0.014 0.82 1.42 7.19 331.1 LiInF.sub.4 .fwdarw. 0.333 Fe.sub.2PO.sub.4F + 0.333 InPO.sub.4 + LiF Li.sub.2SnF.sub.6 0.75 LiFePO.sub.4 + 0.25 0.33 0.40 −0.010 0.59 0.99 4.00 594.7 Li.sub.2SnF.sub.6 .fwdarw. 0.375 Fe.sub.2PO.sub.4F + 0.125 LiSn.sub.2(PO.sub.4).sub.3 + 1.125 LiF LiCeF.sub.5 0.727 LiFePO.sub.4 + 0.273 0.38 0.45 −0.004 0.24 0.69 2.83 841.4 LiCeF.sub.5 .fwdarw. 0.364 Fe.sub.4PO.sub.4F + 0.091 CeO.sub.2 + 0.182 CeP.sub.2O.sub.7 + LiF LiBiF.sub.4 0.333 LiBiF.sub.4 + 0.667 0.50 0.60 −0.005 0.29 0.89 3.06 778.5 LiFePO.sub.4 .fwdarw. 0.333 BiPO.sub.4 + 0.333 Fe.sub.2PO.sub.4F + LiF LiMnF.sub.4 0.5 LiFePO.sub.4 + 0.5 1.00 1.20 −0.059 3.47 4.67 33.86 70.3 LiMnF.sub.4 .fwdarw.0.25 Mn.sub.2PO.sub.4F + 0.25 Li.sub.3FeF.sub.6 + 0.25 LiFePO.sub.4F LiMnF.sub.6 0.182 LiFePO.sub.4 + 0.818 4.49 5.38 −0.271 15.94 21.32 121.25 19.6 LiMnF.sub.6 .fwdarw. 0.818 LiMnF.sub.4 + 0.182 LiPF.sub.6 + 0.182 FeF.sub.3 + 0.364 O.sub.2 Li.sub.2MnF.sub.5 0.5 LiFePO.sub.4 + 0.5 1.00 1.20 −0.048 2.82 4.02 24.55 97.0 Li.sub.2MnF.sub.5 .fwdarw. 0.25 Mn.sub.2PO.sub.4F + 0.25 Li.sub.3FeF.sub.6 + 0.25 LiFePO.sub.4F + 0.5 LiF Li.sub.2MnF.sub.6 0.6 LiFePO.sub.4 + 0.4 0.67 0.80 −0.085 5.00 5.80 31.72 75.1 Li.sub.2MnF.sub.6 .fwdarw. 0.2 LiMnPO.sub.4F + 0.1 Mn.sub.2PO.sub.4F + 0.3 Li.sub.3FeF.sub.6 + 0.3 LiFePO.sub.4F Li.sub.2FeF.sub.6 0.25 LiFePO.sub.4 + 0.75 3.00 3.59 −0.180 10.59 14.18 77.19 30.9 Li.sub.2FeF.sub.6 .fwdarw. 0.083 Fe.sub.2P.sub.3(O.sub.3F).sub.3 + 0.25 FeF.sub.3 + 0.583 Li.sub.3FeF.sub.6 + 0.125 O.sub.2 LiFe.sub.2F.sub.6 0.6 LiFePO.sub.4 + 0.4 0.67 0.80 −0.016 0.94 1.74 7.48 318.4 LiFe.sub.2F.sub.6 .fwdarw. 0.5 Fe.sub.2PO.sub.4F + 0.1 LiFePO.sub.4F + 0.3 Li.sub.3FeF.sub.6 LiFeF.sub.6 0.182 LiFePO.sub.4 + 0.818 4.49 5.38 −0.357 21.00 26.38 149.24 16.0 LiFeF.sub.6 .fwdarw. 0.182 LiPF.sub.6 + 0.727 FeF.sub.3 + 0.273 Li.sub.3FeF.sub.6 + 0.364 O.sub.2 Li.sub.3FeF.sub.6 0.667 LiFePO.sub.4 + 0.333 0.50 0.60 −0.003 0.18 0.78 4.07 585.6 Li.sub.3FeF.sub.6 .fwdarw. 0.333 Fe.sub.2PO.sub.4F + 0.333 LiFePO.sub.4F + 1.333 LiF Li.sub.2MoF.sub.6 0.4 Li.sub.2MoF.sub.6 + 0.6 0.67 0.80 −0.020 1.18 1.98 8.82 269.9 LiFePO.sub.4 .fwdarw. 0.2 LiMo.sub.2(PO.sub.4).sub.3 + 0.6 FeF.sub.2 + 1.2 LiF

    [0073] The 11 Li-M-F compounds with a greater “LiFePO.sub.4 stability score” than AlF.sub.3 were further assessed for reactivity with H.sub.2O and found not to react with H.sub.2O. The HF reactivity was also determined for the 11 Li-M-F compounds where, because AlF.sub.3 is stable against HF, Li.sub.2NiF.sub.4 was used as the reference material to provide an “HF score” and the results shown in Table 12.

    TABLE-US-00012 TABLE 12 HF stability with Li—M—F candidate compounds. Ratio Ratio vs. E.sub.rxn E.sub.rxn vs. per HF Li—M—F HF Reaction (Li—M—F:HF) Li.sub.2NiF.sub.4 (eV/atom) Li.sub.2NiF.sub.4 Sum mg score Li.sub.3AlF.sub.6 0.25 Li.sub.3AlF.sub.6 + 0.75 HF .fwdarw. 0.33 0.67 −0.061 0.81 1.48 9.15 147.2 0.75 LiHF.sub.2 + 0.25 AlF.sub.3 Li.sub.3ScF.sub.6 0.25 Li.sub.3ScF.sub.6 + 0.75 HF .fwdarw. 0.33 0.67 −0.080 1.07 1.73 9.64 139.6 0.75 LiHF.sub.2+ 0.25 ScF.sub.3 Li.sub.2NiF.sub.4 0.333 Li.sub.2NiF.sub.4 + 0.667 HF .fwdarw. 0.50 1.00 −0.075 1.00 2.00 13.46 100.0 0.667 LiHF.sub.2 + 0.333 NiF.sub.2 LiYF.sub.4 0.5 HF + 0.5 LiYF.sub.4 .fwdarw. 0.5 1.00 2.00 −0.030 0.40 2.40 13.97 96.4 LiHF.sub.2 + 0.5 YF.sub.3 LiInF.sub.4 0.5 HF + 0.5 LiInF.sub.4 .fwdarw. 0.5 1.00 2.00 −0.045 0.60 2.60 13.15 102.4 InF.sub.3 + 0.5 LiHF.sub.2 Li.sub.2SnF.sub.6 Stable 0.00 0.00 0.000 0.00 0.00 0.00 Best (Infinite) LiCeF.sub.5 0.5 HF + 0.5 LiCeF.sub.5 .fwdarw. 0.5 1.00 2.00 −0.041 0.55 2.55 10.52 127.9 CeF.sub.4 + 0.5 LiHF.sub.2 LiBiF.sub.4 0.5 LiBiF.sub.4 + 0.5 HF .fwdarw. 0.5 1.00 2.00 −0.038 0.51 2.51 8.59 156.8 BiF.sub.3 + 0.5 LiHF.sub.2 LiFe.sub.2F.sub.6 0.5 HF + 0.5 LiFe.sub.2F.sub.6 .fwdarw. 0.5 1.00 2.00 −0.028 0.37 2.37 10.20 131.9 FeF.sub.2 + 0.5 LiHF.sub.2 + 0.5 FeF.sub.3 Li.sub.3FeF.sub.6 0.75 HF + 0.25 Li.sub.3FeF.sub.6 .fwdarw. 0.33 0.67 −0.064 0.85 1.52 7.97 168.9 0.75 LiHF.sub.2 + 0.25 FeF.sub.3 Li.sub.2MoF.sub.6 0.333 Li.sub.2MoF.sub.6 + 0.667 HF .fwdarw. 2.00 4.00 −0.016 0.21 4.21 18.83 71.5 0.167 MoF.sub.5 + 0.167 MoF.sub.3 + 0.667 LiHF.sub.2

    [0074] For the 10 Li-M-F compounds with an HF score of 100% or greater, the LiF reactivity was determined and it was found that LiFe.sub.2F.sub.6 reacts with LiF. For the 9 Li-M-F compounds stable to LiF, the PF.sub.5.sup.− reactivity for these Li-M-F candidates was determined as compared to Li.sub.2NiF.sub.4 to provide a “PF.sub.5.sup.− score” (similar to the determination of HF score) as illustrated in Table 13. Further, similar to the determination of LiFePO.sub.4 stability, HF reactivity, and PF.sub.5.sup.− reactivity, the LiOH reactivity for the 9 Li-M-F compounds was determined then normalized to the case of Li.sub.2NiF.sub.4 to provide a “LiOH score,” as indicated in Table 14.

    TABLE-US-00013 TABLE 13 PF.sub.5 stability of Li—M—F candidate compounds. Ratio vs. E.sub.rxn E.sub.rxn vs. per PF.sub.5.sup.− Li—M—F PF.sub.5 Reaction Ratio Li.sub.2NiF.sub.4 (eV/atom) Li.sub.2NiF.sub.4 Sum mg score Li.sub.3AlF.sub.6 0.25 Li.sub.3AlF.sub.6 + 0.75 PF.sub.5 .fwdarw. 0.75 0.33 0.67 −0.038 0.83 1.49 9.23 145.9 LiPF.sub.6 + 0.25 AlF.sub.3 Li.sub.3ScF.sub.6 0.25 Li.sub.3ScF.sub.6 + 0.75 PF.sub.5 .fwdarw. 0.75 0.33 0.67 −0.048 1.04 1.71 9.51 141.5 LiPF.sub.6 + 0.25 ScF.sub.3 Li.sub.2NiF.sub.4 0.333 Li.sub.2NiF.sub.4 + 0.667 PF.sub.5 .fwdarw. 0.50 1.00 −0.046 1.00 2.00 13.46 100.0 0.667 LiPF.sub.6 + 0.333 NiF.sub.2 LiYF.sub.4 0.5 PF.sub.5 + 0.5 LiYF.sub.4 .fwdarw. 0.5 1.00 2.00 −0.022 0.48 2.48 14.42 93.3 LiPF.sub.6 + 0.5 YF.sub.3 LiInF.sub.4 0.5 PF.sub.5 + 0.5 LiInF4 .fwdarw. 0.5 1.00 2.00 −0.032 0.70 2.70 13.63 98.8 LiPF.sub.6 + 0.5 InF.sub.3 Li.sub.2SnF.sub.6 Stable 0.00 0.00 0.000 0.00 0.00 0.00 Best (Infinite) LiCeF.sub.5 0.5 PF.sub.5 + 0.5 LiCeF.sub.5 .fwdarw. 0.5 1.00 2.00 −0.030 0.65 2.65 10.96 122.9 CeF.sub.4 + 0.5 LiPF.sub.6 LiBiF.sub.4 0.5 LiBiF.sub.4 + 0.5 PF.sub.5 .fwdarw. 0.5 BiF.sub.3 + 1.00 2.00 −0.027 0.59 2.59 8.86 151.9 0.5 LiPF.sub.6 Li.sub.3FeF.sub.6 0.5 PF.sub.5 + 0.5 LiFe.sub.2F.sub.6 .fwdarw. 0.5 0.33 0.67 −0.022 0.48 1.14 6.01 224.2 LiPF.sub.6 + 0.5 FeF.sub.2 + 0.5 FeF.sub.3

    TABLE-US-00014 TABLE 14 LiOH stability of Li—M—F candidate compounds Ratio vs. E.sub.rxn E.sub.rxn vs. per LiOH Li—M—F LiOH Reaction Ratio Li.sub.2NiF.sub.4 (eV/atom) Li.sub.2NiF.sub.4 Sum mg score Li.sub.3AlF.sub.6 0.25 Li.sub.3AlF.sub.6 + 0.75 LiHO .fwdarw. 0.25 0.33 0.17 −0.076 0.85 1.02 6.31 213.4 H.sub.2O + 0.25 AlHO.sub.2 + 1.5 LiF Li.sub.3ScF.sub.6 0.25 Li.sub.3ScF.sub.6 + 0.75 LiHO .fwdarw. 0.25 0.33 0.17 −0.068 0.76 0.93 5.18 260.0 H.sub.2O + 0.25 ScHO.sub.2 + 1.5 LiF Li.sub.2NiF.sub.4 0.333 Li.sub.2NiF.sub.4 + 0.667 LiHO .fwdarw. 2.00 1.00 −0.089 1.00 2.00 13.46 100.0 0.333 NiO + 0.333 H.sub.2O + 1.333 LiF LiYF.sub.4 0.75 LiHO + 0.25 LiYF.sub.4 .fwdarw. 0.25 3.00 1.50 −0.045 0.51 2.01 11.67 115.3 YHO.sub.2 + 0.25 H.sub.2O + LiF LiInF.sub.4 0.75 LiHO + 0.25 LiInF.sub.4 .fwdarw. 0.25 3.00 1.50 −0.151 1.70 3.20 16.17 83.3 In(HO).sub.3 + LiF Li.sub.2SnF.sub.6 0.8 LiHO + 0.2 Li.sub.2SnF.sub.6 .fwdarw. 0.4 H.sub.2O + 4.00 2.00 −0.152 1.71 3.71 15.04 89.5 1.2 LiF + 0.2 SnO.sub.2 LiCeF.sub.5 0.2 LiCeF.sub.5 + 0.8 LiHO .fwdarw. 0.2 4.00 2.00 −0.152 1.71 3.71 15.32 87.9 CeO.sub.2 + 0.4 H.sub.2O + LiF LiBiF.sub.4 0.25 LiBiF.sub.4 + 0.75 LiHO .fwdarw. 0.375 3.00 1.50 −0.097 1.09 2.59 8.87 151.7 H.sub.2O + LiF + 0.125 Bi.sub.2O.sub.3 Li.sub.3FeF.sub.6 0.75 LiHO + 0.25 Li.sub.3FeF.sub.6 .fwdarw. 0.25 3.00 1.50 −0.107 1.20 2.70 14.17 95.0 H.sub.2O + 1.5 LiF + 0.25 FeHO.sub.2

    [0075] While certain embodiments have been illustrated and described, it should be understood that changes and modifications can be made therein in accordance with ordinary skill in the art without departing from the technology in its broader aspects as defined in the following claims.

    [0076] The embodiments, illustratively described herein may suitably be practiced in the absence of any element or elements, limitation or limitations, not specifically disclosed herein. Thus, for example, the terms “comprising,” “including,” “containing,” etc. shall be read expansively and without limitation. Additionally, the terms and expressions employed herein have been used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the claimed technology. Additionally, the phrase “consisting essentially of” will be understood to include those elements specifically recited and those additional elements that do not materially affect the basic and novel characteristics of the claimed technology. The phrase “consisting of” excludes any element not specified.

    [0077] The present disclosure is not to be limited in terms of the particular embodiments described in this application. Many modifications and variations can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. Functionally equivalent methods and compositions within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is to be understood that this disclosure is not limited to particular methods, reagents, compounds, compositions, or devices, which can of course vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

    [0078] In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

    [0079] As will be understood by one skilled in the art, for any and all purposes, particularly in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as “up to,” “at least,” “greater than,” “less than,” and the like, include the number recited and refer to ranges which can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member.

    [0080] All publications, patent applications, issued patents, and other documents referred to in this specification are herein incorporated by reference as if each individual publication, patent application, issued patent, or other document was specifically and individually indicated to be incorporated by reference in its entirety. Definitions that are contained in text incorporated by reference are excluded to the extent that they contradict definitions in this disclosure.

    [0081] Other embodiments are set forth in the following claims.