Additives for electrolyte and cathode material in Li-ion batteries comprising metal-based cathode material which produces M.SUP.2+ .metal ions
12015147 ยท 2024-06-18
Assignee
Inventors
- Charlotte Mallet (Montr?al, CA)
- Jean-Christophe Daigle (St-Bruno-de-Montarville, CA)
- Sylviane Rochon (Saint-Ad?lphe, CA)
- Karim Zaghib (Longueuil, CA)
Cpc classification
C08F2810/50
CHEMISTRY; METALLURGY
C08F2438/01
CHEMISTRY; METALLURGY
Y02E60/10
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
H01M10/0525
ELECTRICITY
International classification
C08F212/14
CHEMISTRY; METALLURGY
H01M10/0525
ELECTRICITY
Abstract
Method of improving the performance of a Li-ion battery comprising metal-based cathode material which produces M.sup.2+ metal ions. The method comprises using a small organic compound in association with the electrolyte of the battery or using a polymer compound in association with the cathode active material of the battery. The small organic compound and the polymer compound comprise at least one chemical group suitable for forming complexes with the M.sup.2+ metal ions thereby preventing dissolution thereof.
Claims
1. A polymer compound having a general formula VI outlined below ##STR00015## wherein: Q and Q are each independently a 5 to 12-member ring or bicycle ring, optionally either ring comprises one or more heteroatom which are the same or different; L is a linker comprising alkyl groups; Ri and Ri are each independently selected from H, alkyl, cycloalkyl, alkene, alkyne, aryl and alkylaryl, alkoxy, thioalkoxy, OH, SH, NH.sub.2, a halogen atom, a halogeno alkyl, a halogeno alkoxy, a halogeno thioalkoxy, a cyano alkyl, a cyano alkene, a cyano alkyne, CN, NO.sub.2, SO.sub.2, COOH and acyloxycarbonyl, with the proviso that at least one of Ri comprises a heteroatom and at least one of Ri is different from H; n and m are each independently an integer from 0 to 11 with the proviso that they are not both 0 at the same time; and the one or more heteroatom of Q or Q is selected from O, S and N.
2. The polymer according to claim 1, wherein at least two of Ri comprise a heteroatom, and the at least two of Ri are attached to consecutive carbon atoms of the ring; or when Q is a bicycle ring the at least two of Ri are spatially close to each other.
3. The polymer according to claim 1, wherein the at least one Ri is a halogen atom, optionally F.
4. The polymer compound according to claim 1 having a general formula VII outlined below ##STR00016## wherein: at least two of Ri comprise a heteroatom, and the at least two of Ri are attached to consecutive carbon atoms of the ring; or when Q is a bicycle ring the at least two of Ri are spatially close to each other; and the at least one Ri is a halogen atom, optionally F.
5. The polymer compound according to claim 1 having a general formula VIII outlined below ##STR00017## wherein: both R.sub.1 and R.sub.2 comprise a heteroatom, optionally both R.sub.1 and R.sub.2 comprise a heteroatom, and are attached to consecutive carbon atoms of the ring; and R.sub.1-5 are each a halogen atom, optionally F.
6. The polymer compound according to claim 1 having a general formula IX outlined below ##STR00018## wherein: R.sub.3, R.sub.4 and R.sub.6-9 are each independently H or a C.sub.1-6 alkyl; R.sub.1-5 are each a halogen atom, optionally F; L is constituted of repeating units of CR.sub.6R.sub.7 and CR.sub.8R.sub.9; and X.sub.1 and X.sub.2 are each independently a heteroatom, optionally the X.sub.1 or X.sub.2 heteroatom is O, S or N.
7. The polymer compound according to claim 6 having a formula P outlined below ##STR00019##
8. The polymer compound according to claim 6 having a formula P outlined below ##STR00020##
9. The polymer according to claim 7, which is selected from the group consisting of: polymer of formula P, which comprises 48 mol % of dimethoxystyrene moities (Polymer dimethoxy-1); polymer of formula P, which comprises 70 mol % of dimethoxystyrene moities (Polymer dimethoxy-2); and polymer of formula P, which comprises 100 mol % of dimethoxystyrene moities (Polymer dimethoxy-3).
10. The polymer according to claim 8, which is: polymer of formula P, which comprises 50 mol % of dihydroxystyrene moities (Polymer difydroxy-1).
11. A method of preventing metal ions dissolution in a Li-ion battery comprising metal-based cathode material which produces M.sup.2+ metal ions, the method comprising using adding a polymer compound in association with to the cathode material of the battery, wherein the polymer compound is as defined in claim 1.
12. A cathode material comprising the polymer compound as defined in claim 1.
13. A battery comprising the cathode material as defined in claim 12.
14. A method for preparing the polymer compound as defined in claim 1, comprising submitting a dialkyloxystyrene compound and a pentahalogenostyrene compound to a random copolymerization to obtain an alkyoxystyrene polymer; and optionally submitting the alkyoxystyrene polymer to a dealkylation process to obtain a hydroxy polymer compound.
15. The method according to claim 14, wherein the dialkyloxystyrene compound is dimethoxystyrene, and the pentahalogenostyrene compound is pentafluorostyrene.
16. A method for preparing the polymer compound of formula P as defined in claim 7, comprising submitting dimethoxystyrene and pentafluorostyrene to a random copolymerization.
17. A method for preparing the polymer compound of formula P as defined in claim 8, comprising submitting a polymer compound of formula P to a demethylation process: ##STR00021##
18. A method for preparing the polymer compound as defined in claim 1, comprising submitting a dialkyloxystyrene compound and a pentahalogenostyrene compound to a polymerization process which is atom transfer radical polymerization (ATRP), atom transfer radical addition polymerization (ATRAP), retarded anionic polymerization (RAP), or cationic polymerization.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
(2) In the Appended Drawings:
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DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
(25) Before the present invention is further described, it is to be understood that the invention is not limited to the particular embodiments described below, as variations of these embodiments may be made and still fall within the scope of the appended claims. It is also to be understood that the terminology employed is for the purpose of describing particular embodiments; and is not intended to be limiting. Instead, the scope of the present invention will be established by the appended claims.
(26) In order to provide a clear and consistent understanding of the terms used in the present specification, a number of definitions are provided below. Moreover, unless defined otherwise, all technical and scientific terms as used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this disclosure pertains.
(27) The use of the word a or an when used in conjunction with the term comprising in the claims and/or the specification may mean one, but it is also consistent with the meaning of one or more, at least one, and one or more than one. Similarly, the word another may mean at least a second or more.
(28) As used in this specification and claim(s), the words comprising (and any form of comprising, such as comprise and comprises), having (and any form of having, such as have and has), including (and any form of including, such as include and includes) or containing (and any form of containing, such as contain and contains), are inclusive or open-ended and do not exclude additional, unrecited elements or process steps.
(29) As used herein when referring to numerical values or percentages, the term about includes variations due to the methods used to determine the values or percentages, statistical variance and human error. Moreover, each numerical parameter in this application should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.
(30) Term alkyl or alk as used herein, represents a monovalent group derived from a straight or branched chain saturated hydrocarbon comprising, unless otherwise specified, from 1 to 15 carbon atoms and is exemplified by methyl, ethyl, n- and iso-propyl, n-, sec-, iso- and tert-butyl, neopentyl and the like and may be optionally substituted with one, two, three or, in the case of alkyl groups comprising two carbons or more, four substituents.
(31) The term alkoxy or alkyloxy as used interchangeably herein, represents an alkyl group attached to the parent molecular group through an oxygen atom.
(32) The term alkylthio or thioalkoxy as used interchangeably herein, represents an alkyl group attached to the parent molecular group through a sulfur atom.
(33) The term alkylene as used herein, represents a saturated divalent hydrocarbon group derived from a straight or branched chain saturated hydrocarbon by the removal of two hydrogen atoms, and is exemplified by methylene, ethylene, isopropylene and the like.
(34) The term alkenyl as used herein, represents monovalent straight or branched chain groups of, unless otherwise specified, from 2 to 15 carbons, such as, for example, 2 to 6 carbon atoms or 2 to 4 carbon atoms, containing one or more carbon-carbon double bonds and is exemplified by ethenyl, 1-propenyl, 2-propenyl, 2-methyl-1-propenyl, 1-butenyl, 2-butenyl and the like and may be optionally substituted with one, two, three or four substituents.
(35) The term alkynyl as used herein, represents monovalent straight or branched chain groups of from two to six carbon atoms comprising a carbon-carbon triple bond and is exemplified by ethynyl, 1-propynyl, and the like and may be optionally substituted with one, two, three or four substituents.
(36) The term cycloalkyl as used herein, represents a monovalent saturated or unsaturated non-aromatic cyclic hydrocarbon group of three to eight carbon atoms, unless otherwise specified, and is exemplified by cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, bicyclo[2.2.1]heptyl and the like.
(37) The term halogen or halo as used interchangeably herein, represents F, Cl, Br and I.
(38) The term heteroatom, as used herein, is understood as being oxygen, sulfur or nitrogen.
(39) The inventors have designed and prepared an additive for use in association with the electrolyte in a Li-ion battery comprising a metal-based cathode material capable of producing M.sup.2+ metal ions. The additive of the invention is added to the electrolyte; and allows for the prevention of the M.sup.2+ ions dissolution.
(40) More specifically, the additive of the invention for use in association with the electrolyte is a small organic molecule as described herein and having general formulae I-V. Such small organic compounds are exemplified by Compounds A-D. The small organic compound comprises at least one chemical group suitable for forming complexes with the M.sup.2+ metal ions. Such chemical group are apparent to a skilled person. Also, the small organic compound is compatible with the electrolyte as well as other components of the battery.
(41) Also, the inventors have designed and prepared an additive (binder) for use in association with the cathode material in a Li-ion battery comprising a metal-based cathode material capable of producing M.sup.2+ metal ions. The additive according to this aspect of the invention is a binder. The binder is mixed with the cathode material; and allows for the prevention of the M.sup.2+ ions dissolution.
(42) More specifically, the additive or binder of the invention for use in association with the cathode material is a polymer compound as described below and having general formulae VI-IX. Such polymer compounds are exemplified by Polymer P and Polymer P. The polymer compound comprises at least one chemical group suitable for forming complexes with the M.sup.2+ metal ions. Such chemical group are apparent to a skilled person. Also, the polymer compound is compatible with the cathode active material as well as other components of the battery.
(43) The present invention is illustrated in further details by the following non-limiting examples.
Small Organic Molecule for Use as Additive in Association with the Electrolyte
(44) Example 1 Preparation of Compound A: 3,4-dimethoxybenzaldehyde (1 equivalent) and malanonitrile (1.5 equivalent) were solubilized in chloroform. Under stirring, 3 drops of trimethylamine were added. After 1 night at 60? C., the solvent was evaporated. The crude was washed with water 3 times and extracted by dichloromethane. The organic phases were dried with MgSO.sub.4 and the solvent evaporated. The orange solid was purified by gel chromatography (eluent: hexanes:dichloromethane (80:20)) to give light yellow solid (70%).
(45) Compound B, Compound C and Compound D are commercially available and were used as received.
Polymer Compound for Use as Additive (Binder) in Association with the Cathode Material
(46) The polymer compound according to the invention is obtained from pentafluorostyrene and dimethoxystyrene as outlined in Scheme 1 below. Pentafluorostyrene allows for a good compatibility with PVDF and a good electrochemical stability. The level of incorporation of dimethoxystyrene in the polymer according to the invention is around 40 mol % or higher. In this regard, Polymer dimethoxy-1 (polymer comprising 48 mol % of dimethoxystyrene moities), Polymer dimethoxy-2 (polymer comprising 70 mol % of dimethoxystyrene moities) and Polymer dimethoxy-3 (polymer comprising 100 mol % of dimethoxystyrene moities) were prepared as outlined at Example 2 below. The preparation is generally based on a random copolymerization of dimethoxystyrene (DMSt) and pentafluorostyrene (PFS). Dimethoxystyrene forms a complex with the metals ions including Mn.sup.2+ ions, therefore limiting their diffusion throughout the electrolyte, and thus their deposition on the anode side.
(47) ##STR00013##
(48) The polymer compound of the invention with free hydroxy groups (polymer comprising dihydroxystyrene moieties) is obtained as outlined in Scheme 2. In this regard, Polymer dihydroxy-1 (polymer comprising 50 mol % of dihydroxystyrene moities) was prepared.
(49) ##STR00014##
(50) Example 2 Preparation of Polymer dimethoxy-1: DMSt and PFS were first passed through basic aluminum oxide (alumina, Al.sub.2O.sub.3). Polymerization was achieved by introducing 50 mL of dioxane, 3.2 g of DMSt and 3.7 g of PFS into a 100 mL round bottom flask. The solution was then stirred with a magnetic bar for 30 minutes and bubbled with nitrogen (N.sub.2). 80 mg of AIBN was then added to the obtained solution. A condenser was then attached to the round bottom flask and the reaction mixture was heated at 80? C. for 12 hours under N.sub.2. The resulting solution was then cooled down to room temperature and poured in 10 volumes of methanol. The supernatant was separated from the precipitated polymer, which was then dried under vacuum at 60? C. for 12 hours. Yield=4.1 g, 48 mol % in DMSt, M.sub.n=26 000 g/mol, PDI=1.7.
(51) As will be understood by a skilled person, Polymer dimethoxy-2 and Polymer dimethoxy-3 are prepared by the same procedure described in Example 2.
(52) Example 3 Preparation of a polymer comprising dihydroxystyrene moieties (Polymer dihydroxy-1): Polymer dimethoxy-2 or 3 obtained in Example 2 was subjected to hydrolysis according to a method described by Westwood et al. [6], 0.50 g of Polymer dimethoxy-2 or 3 and 4.3 mL of BBr 3 in DCM 1.0M were used.
(53) Example 4 Preparation of the cathode material according to the invention: the hybrid cathode pastes were prepared by mechanically mixing (thinky Mixer SR-500) of additives if present, active material, acetylene black (Denka HS-100L), carbon fiber (VGCF-SDH-HC) and PVDF (130 mg/mol) in NMP. The resulting viscous slurry was cast by the doctor Blade method uniformly onto an aluminum foil serving as a current collector, dried at 80? C. under vacuum and roll-pressed with Rolling Machine (MSK-2150) at 63 ?m to achieve an electrode active layer density 8.5 mg/cm 2. Electrodes were further dried under vacuum at 150? C. before use.
(54) As will be understood by a skilled person, the polymer according to the invention may be prepared by different polymerization processes, such processes include but are not limited to atom transfer radical polymerization (ATRP), atom transfer radical addition polymerization (ATRAP), retarded anionic polymerization (RAP), cationic polymerization or the like.
(55) Referring to the figures,
(56) As can be seen in
(57) Compound B was also used as additive in the electrolyte. The results obtained are outlined in
(58) As can be seen in
(59) Compound C and Compound D were also used as additive in the electrolyte. The results obtained are outlined in
(60) Referring to
(61) Referring to
(62) As will be understood by a skilled person, the additive for use in association with the electrolyte and the additive (binder) for use in association the cathode active material are adapted to be compatible with the components of the battery including the electrolyte and the cathode active material.
(63) The scope of the claims should not be limited by the preferred embodiments set forth in the examples; but should be given the broadest interpretation consistent with the description as a whole.
(64) The present description refers to a number of documents, the content of which is herein incorporated by reference in their entirety.
REFERENCES
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