Sulfide Based All-Solid-State Batteries Enabled by Bipolar Stacking
20250158113 ยท 2025-05-15
Inventors
Cpc classification
H01M4/525
ELECTRICITY
H01M10/0585
ELECTRICITY
H01M4/1391
ELECTRICITY
H01M2004/021
ELECTRICITY
International classification
H01M4/1391
ELECTRICITY
H01M4/36
ELECTRICITY
H01M4/525
ELECTRICITY
H01M4/62
ELECTRICITY
Abstract
Described herein is an all-solid-state battery comprising two or more mono cells connected in series, wherein: each mono cell comprises a lithium-based cathode, a sulfide solid electrolyte, and an anode; and adjacent mono cells are connected through a single, shared current collector in contact with a cathode and an anode of adjacent mono cells. The all-solid-state battery can be fabricated by stacking freestanding layers of the lithium-based cathode, the sulfide solid electrolyte, the anode, and the current collector in a bipolar design, and pressing the layers together to form the all-solid-state battery. The lithium-ion battery -can be incorporated into portable electronics and electric vehicles.
Claims
1. An all-solid-state battery comprising two or more mono cells connected in series, wherein: each mono cell comprises a lithium-based cathode, a sulfide solid electrolyte, and an anode; and adjacent mono cells are connected through a single, shared current collector in contact with a cathode and an anode of adjacent mono cells.
2. The all-solid-state battery of claim 1, wherein the two or more mono cells are arranged uniaxially.
3. The all-solid-state battery of claim 1, wherein the lithium-based cathode, the sulfide solid electrolyte, the anode, the shared current collector, or any combination thereof, is in the form of a layer.
4. The all-solid-state battery of claim 1, wherein the lithium-based cathode has a thickness of about 50 m to about 200 m, or wherein the lithium-based cathode has a thickness of about 96 m.
5. (canceled)
6. (canceled)
7. The all-solid-state battery of claim 1, wherein the sulfide solid electrolyte has a thickness of about 20 m to about 1 millimeter, or wherein the sulfide solid electrolyte has a thickness of about 47 m.
8. (canceled)
9. (canceled)
10. The all-solid-state battery of claim 1, wherein the anode has a thickness of about 20 m to about 100 m, or wherein the anode has a thickness of about 50 m.
11. (canceled)
12. (canceled)
13. The all-solid-state battery of claim 1, wherein the shared current collector has a thickness of about 10 m to about 50 m, or wherein the shared current collector has a thickness of about 15 m.
14. (canceled)
15. The all-solid-state battery of claim 1, wherein lateral size of the sulfide solid electrolyte is greater than lateral size of the lithium-based cathode and lateral size of the anode.
16. The all-solid-state battery of claim 1, wherein the shared current collector is carbon paper or stainless steel.
17. (canceled)
18. The all-solid-state battery of claim 1, wherein: (a) the lithium-based cathode comprises single-crystal LiNi.sub.0.8Mn.sub.0.1 Co.sub.0.1O.sub.2 coated with Li.sub.2SiO.sub.x, wherein x is about 1 to about 3, (b) the sulfide solid electrolyte comprises Li.sub.6PS.sub.5Cl, (c) the anode comprises a mixture of nano-silicon (Si), Li.sub.6PS.sub.5Cl, and carbon black, or (d) any combination thereof.
19. The all-solid-state battery of claim 1, wherein the lithium-based cathode, the sulfide solid electrolyte, the anode, or any combination thereof, further comprises an amphipathic binder.
20. (canceled)
21. (canceled)
22. (canceled)
23. The all-solid-state battery of claim 1, wherein the anode comprises a mixture of nano-silicon (Si), Li.sub.6PS.sub.5Cl, and carbon black having a weight ratio of about 6:3:1.
24. (canceled)
25. The all-solid-state battery of claim 19, wherein the amphipathic binder is alkyl cellulose or ethyl cellulose.
26. (canceled)
27. The all-solid-state battery of claim 1, further comprising an anode current collector in contact with an anode of a first mono cell in series, and a cathode current collector in contact with a cathode of a last mono cell in series.
28. A mono cell all-solid-state battery comprising first and second stainless steel current collectors, a cathode comprising single-crystal LiNi.sub.0.8Mn.sub.0.1Co.sub.0.1O.sub.2 coated with Li.sub.2SiO.sub.x, wherein x is about 1 to about 3, a sulfide solid electrolyte, and an anode, wherein the first stainless steel current collector is in contact with the cathode, the cathode is in contact with the sulfide solid electrolyte, the sulfide solid electrode is in contact with the anode, and the anode is in contact with the second stainless steel current collector.
29. A system comprising an all-solid-state battery of claim 1 connected to an energy source or an electrical device.
30. A method of fabricating a lithium-based cathode, comprising: a) providing a dispersion of an amphipathic binder, Li.sub.6PS.sub.5Cl, single-crystal LiNi.sub.0.8Mn.sub.0.1Co.sub.0.1O.sub.2 coated with Li.sub.2SiO.sub.x wherein x is about 1 to about 3 in a solvent; and b) vacuum filtering the dispersion through a filter, thereby forming a layer of lithium-based cathode.
31. The method of claim 30, wherein the solvent is an organic solvent, wherein the amphipathic binder is ethyl cellulose, or wherein the solvent is an organic solvent and the amphipathic binder is ethyl cellulose.
32. (canceled)
33. The method of claim 30, wherein the amphipathic binder is about 1.0 weight percent (wt. %) to about 3.0 wt. % of the dispersion or wherein the amphipathic binder is about 1.0 wt. % of the dispersion.
34. (canceled)
35. The method of claim 30, further comprising; (a) removing the layer of lithium-based cathode from the filter to form a freestanding layer of lithium-based cathode, (b) evaporating the solvent from the layer of lithium-based cathode or freestanding layer of lithium-based cathode, or (c) both (a) and (b).
36. (canceled)
37. A method of fabricating an anode, comprising: a) providing a dispersion of an amphipathic binder, Si, Li.sub.6PS.sub.5Cl, and carbon black in a solvent; and b) vacuum filtering the dispersion through a filter, thereby forming a layer of anode.
38. The method of claim 37, wherein the solvent is an organic solvent, wherein the amphipathic binder is ethyl cellulose, or wherein the solvent is an organic solvent and the amphipathic binder is ethyl cellulose.
39. (canceled)
40. The method of claim 37, wherein the ethyl cellulose is about 1.0 wt. % to about 5.0 wt. % of the dispersion, or wherein the ethyl cellulose is about 1.0 wt. % of the dispersion.
41. (canceled)
42. The method of claim 37, further comprising: (a) removing the layer of anode from the filter to form a freestanding layer of anode, (b) evaporating the solvent from the layer of anode or freestanding layer of anode or (c) both (a) and (b).
43. (canceled)
44. A method of fabricating the all-solid-state battery of claim 1, the method comprising stacking freestanding layers of the lithium-based cathode, the sulfide solid electrolyte, the anode, and the current collector in a bipolar design, and pressing the layers together to form the all-solid-state battery.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] 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.
[0019] The foregoing will be apparent from the following more particular description of example embodiments, as illustrated in the drawings included in the attached manuscript. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating embodiments.
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DETAILED DESCRIPTION
[0075] A description of example embodiments follows.
[0076] High voltage ASLBs with a bipolar design based on sulfide SE have been fabricated successfully and described herein. Benefiting from the amphipathic property, high binding capability, excellent compatibility with sulfide SE, and high thermal stability, the ethyl cellulose binder enables the successful fabrication of freestanding, robust, and thickness-controllable cathode, SE, and anode layers through vacuum filtration. An interface stabilized high voltage single-crystal LiNi.sub.0.8Mn.sub.0.1Co.sub.0.1O.sub.2 (S-NMC) and nano Si were utilized separately as cathode and anode active material. The corresponding electrochemical performances of the obtained electrode layers have been investigated. Then the mono cell and bipolar-stacked double-layer cell were fabricated, and the electrochemical performances were evaluated. This could enlighten the research interest in investigating bipolar-stacked ASLBs and accelerates the development of ASLBs from lab scale to industrial manufacturing.
[0077] As used herein, singular articles such as a, an and the, and similar referents are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. For example, reference to an all-solid-state battery may refer to one or more all-solid-state batteries. When a referent refers to the plural, the members of the plural can be the same as or different from one another.
[0078] About means within an acceptable error range for the particular value, as determined by one of ordinary skill in the art. Typically, an acceptable error range for a particular value depends, at least in part, on how the value is measured or determined, e.g., the limitations of the measurement system. For example, about can mean within an acceptable standard deviation, per the practice in the art. Alternatively, about can mean a range of 20%, e.g., 10%, 5% or 1% of a given value. It is to be understood that the term about can precede any particular value specified herein, except for particular values used in the Exemplification.
Bipolar Stacked All-Solid-State Batteries
[0079] Described herein is an all-solid-state battery comprising two or more mono cells connected in series, wherein: each mono cell comprises a cathode (e.g., a lithium-based cathode), a sulfide solid electrolyte, and an anode; and adjacent mono cells are connected through a single, shared current collector in contact with a cathode and an anode of adjacent mono cells.
[0080] As used herein, the term all-solid-state battery refers to a battery in which the cathode, electrolyte, and anode are all in solid forms.
[0081] As used herein, the term mono cell or single cell refers to a single cathode in contact with an electrolyte which in turn is in contact with a single anode. A mono cell may also further comprise current collectors that are in contact with the cathode and anode. Mono cells may be connected to one another in series or in parallel to form a larger battery.
[0082] As used herein, the phrase in series refers to mono cells connected in series, wherein the negative terminal or electrode of one battery or mono cell is connected to the positive terminal or electrode of another and so on. There may be a shared current collector between the mono cells, as described above.
[0083] In some aspects, the two or more mono cells are arranged uniaxially, as depicted, for example, in
[0084] In some aspects, the all-solid-state battery further comprises an anode current collector in contact with an anode of a first mono cell in series, and a cathode current collector in contact with a cathode of a last mono cell in series.
[0085] As used herein, the term cathode refers to the battery electrode in which the reduction half-reaction occurs. Examples of cathode materials include: sulfur, Li metal oxides, polyanion oxides, stainless steel, LiNixMnyCozO2 where x+y+z is about 1 such as LiNi.sub.0.8Mn.sub.0.1Co.sub.0.1O.sub.2 (NMC811), LiNi.sub.0.06Mn.sub.0.2Co.sub.0.2O.sub.2 (NMC622), LiNi.sub.0.333Mn.sub.0.333Co.sub.0.33302 (NMC111), and LiFePO.sub.4. In some aspects, the cathode comprises, consists of or consists essentially of (e.g., comprises) sulfur, Li metal oxides, polyanion oxides, stainless steel, LiNi.sub.xMn.sub.yCo.sub.zO.sub.2 where x+y+z is about 1 such as LiNi.sub.0.8Mn.sub.0.1Co.sub.0.1O.sub.2 (NMC811), LiNi.sub.0.06Mn.sub.0.2Co.sub.0.2O.sub.2 (NMC622), LiNi.sub.0.333Mn.sub.0.333Co.sub.0.33302 (NMC111), or LiFePO.sub.4, or any combination thereof. In some aspects, the cathode is a lithium-based cathode. In some aspects, the lithium-based cathode comprises LiNi.sub.0.8Mn.sub.0.1Co.sub.0.1O.sub.2 (e.g., single-crystal LiNi.sub.0.8Mn.sub.0.1Co.sub.0.1O.sub.2).
[0086] Surface coating a cathode, such as a lithium-based cathode, can improve the stability of a battery in accordance with the instant disclosure as, for example, by protecting the solid electrolyte from degradation resulting from contact of the solid electrolyte with the lithium-based cathode. Accordingly, in some aspects, the cathode has a surface coating. Examples of cathode surface coatings can include: LiNbO3, metal oxides that are Li-containing or Li-ion conducting, or Li.sub.2SiO.sub.x wherein x is about 1 to about 5 (e.g., about 1 to about 3). In some aspects, the cathode surface coating comprises, consists of or consists essentially of (e.g., comprises) LiNbO3 or Li.sub.2SiO.sub.x wherein x is about 1 to about 5 (and, in preferred aspects, about 1 to about 3). In some aspects, the cathode surface coating comprises, consists of or consists essentially of (e.g., comprises) Li.sub.2SiO.sub.x wherein x is about 1 to about 5 (and, in preferred aspects, about 1 to about 3).
[0087] In some aspects, the cathode (e.g., the lithium-based cathode) comprises LiNi.sub.0.8Mn.sub.0.1Co.sub.0.1O.sub.2 (e.g., single-crystal of LiNi.sub.0.8Mn.sub.0.1Co.sub.0.1O.sub.2) coated with Li.sub.2SiO.sub.x, wherein x is about 1 to about 3. In some aspects, the cathode (e.g., the lithium-based cathode) comprises LiNi.sub.0.8Mn.sub.0.1Co.sub.0.1O.sub.2 (e.g., single-crystal of LiNi.sub.0.8Mn.sub.0.1Co.sub.0.1O.sub.2) coated with Li.sub.2SiO.sub.x, wherein x is an integer from 1 to 3. In some aspects, the cathode (e.g., the lithium-based cathode) further comprises an amphipathic binder. In some aspects, the amphipathic binder is an alkyl cellulose, such as ethyl cellulose or methyl cellulose. In some aspects, the cathode (e.g., the lithium-based cathode) further comprises ethyl cellulose.
[0088] In some aspects, the cathode (e.g., lithium-based cathode) is in the form of a layer. In some aspects, the cathode (e.g., layer of cathode) has a thickness of about 50 m to about 200 m. In some aspects, the cathode (e.g., layer of cathode) has a thickness of about 50 m to about 150 m. In some aspects, the cathode (e.g., layer of cathode) has a thickness of about 50 m to about 100 m. In some aspects, the cathode (e.g., layer of cathode) has a thickness of about 75 m to about 100 m. In some aspects, the cathode (e.g., layer of cathode) has a thickness of about 96 m.
[0089] As used herein, the term electrolyte refers to a material that transfers ions or charge carrying particles between a battery's electrodes. The electrolyte can be a solid or liquid. Examples of electrolytes include: Li.sub.6PS5Cl, Li.sub.7La.sub.3Zr.sub.2O.sub.12 (LLZO), Li.sub.6.4La.sub.3Zr.sub.1.4Ta.sub.0.6O.sub.12 (LLZTO), Li.sub.3InCl.sub.6, metal hydroxides, LiPF.sub.6, sodium chloride, nitric acid, sulfuric acid, sodium acetate, chloric acid, ion-conducting polymers, and Al.sub.2O.sub.3containing materials. In some aspects, the electrolyte is a sulfide solid electrolyte. Examples of sulfide solid electrolytes include: mixtures comprising Li.sub.2S and sulfides (such as P.sub.2S.sub.5, SiS.sub.2, P.sub.2S.sub.5, GeS.sub.2), Li.sub.10GeP.sub.2Si.sub.2, and Li.sub.6PSSXwhere X=Cl, Br or I. In some aspects, the sulfide solid electrolyte comprises Li.sub.6PSsXwhere X=Cl, Br or I, e.g., Li.sub.6PSSCl.
[0090] In some aspects, the solid electrolyte further comprises an amphipathic binder. In some aspects, the amphipathic binder is an alkyl cellulose, such as ethyl cellulose or methyl cellulose. In some aspects, the solid electrolyte further comprises ethyl cellulose.
[0091] In some aspects, the sulfide solid electrolyte is in the form of a layer. In some aspects, the sulfide solid electrolyte (e.g., layer of sulfide solid electrolyte) has a thickness of about 20 m to about 1 millimeter, e.g., about 20 m to about 500 m, about 20 m to about 400 m, about 20 m to about 250 m, about 20 m to about 100 gm, or about 35 m to about 75 gm. In some aspects, the sulfide solid electrolyte (e.g., layer of sulfide solid electrolyte) has a thickness of about 20 m to about 55 gm. In some aspects, the sulfide solid electrolyte (e.g., layer of sulfide solid electrolyte) has a thickness of about 47 m.
[0092] In some aspects, the sulfide solid electrolyte is configured to inhibit edge shorting of the battery. For example, in some aspects, lateral size of the sulfide solid electrolyte is greater than lateral size of the lithium-based cathode and lateral size of the anode. Such a configuration is depicted, for example, in
[0093] As used herein, the term anode refers to the battery electrode in which the oxidation half-reaction occurs. Examples of anode materials includes: silicon (Si), graphite, alloys comprising tin, cobalt, magnesium, silver, aluminum, and/or antimony, Li.sub.4TisO.sub.12, amorphous carbon, silicon/carbon alloy, lithium oxalates, Li.sub.2CO.sub.3, lithium (Li) metal or foil, or a mixture comprising Si, carbon (C) containing material, and an electrolyte. It will be appreciated by a person skilled in the art that when sulfur is used as the cathode material, the anode material should be lithium-based, such as lithium metal or foil or a pre-lithiated material. In some aspects, the anode comprises, consists of or consists essentially of silicon (Si), graphite, alloys comprising tin, cobalt, magnesium, silver, aluminum, and/or antimony, Li.sub.4TisO.sub.12, amorphous carbon, silicon/carbon alloy, lithium oxalates, Li.sub.2CO.sub.3, lithium (Li) metal or foil, or a mixture comprising Si, carbon (C) containing material, and an electrolyte, or any combination of the foregoing. In some aspects, the anode comprises Si (e.g., nano-silicon, micro-silicon), Li.sub.6PS.sub.5Cl, and carbon black. In some aspects, the anode is a mixture of nano-silicon (Si), Li.sub.6PS.sub.5Cl, and carbon black. In some aspects, the anode is a mixture of micro-silicon (Si), Li.sub.6PS.sub.5Cl, and carbon black. In some aspects, the anode mixture of nano-silicon (Si), Li.sub.6PS.sub.5Cl, and carbon black has a weight ratio of about 6:3:1.
[0094] In some aspects, the anode further comprises an amphipathic binder. In some aspects, the amphipathic binder is an alkyl cellulose, such as ethyl cellulose or methyl cellulose. In some aspects, the anode further comprises ethyl cellulose.
[0095] In some aspects, the anode is in the form of a layer. In some aspects, the anode (e.g., layer of anode) has a thickness of about 40 m to about 100 m. In some aspects, the anode (e.g., layer of anode) has a thickness of about 40 m to about 75 m. In some aspects, the anode (e.g., layer of anode) has a thickness of about 50 m.
[0096] As used herein, the term current collector refers to a material used to conduct electrons between an electrode active material (such as an anode or cathode) and the battery terminals, or the anode of one mono cell to the cathode of another. A current collector can be individually an anode current collector, a cathode current collector, or a shared current collector. Examples of current collectors can include: aluminum (Al, typically used for cathode current collectors), copper (Cu, typically used for anode current collectors), or stainless steel, carbon paper, or carbon black. In some aspects, the shared current collector is carbon (e.g., carbon paper, carbon black) or stainless steel. In some aspects, the shared current collector is stainless steel.
[0097] In some aspects, the shared current collector is in the form of a layer. In some aspects, the shared current collector (e.g., layer of shared current collector) has a thickness of about 10 m to about 50 m. In some aspects, the shared current collector (e.g., layer of shared current collector) has a thickness of about 10 m to about 25 m. In some aspects, the shared current collector (e.g., layer of shared current collector) has a thickness of about 15 m.
[0098] Also described herein is a mono cell all-solid-state battery comprising first and second stainless steel current collectors, a cathode comprising single-crystal LiNi.sub.0.8Mn.sub.0.1Co.sub.0.1O.sub.2 coated with Li.sub.2SiO.sub.x, wherein x is about 1 to about 3, a sulfide solid electrolyte, and an anode, wherein the first stainless steel current collector is in contact with the cathode, the cathode is in contact with the sulfide solid electrolyte, the sulfide solid electrode is in contact with the anode, and the anode is in contact with the second stainless steel current collector.
[0099] Also described herein is an all-solid-state battery that delivers a laboratory scale output voltage of at least about 4.1 V per mono cell.
[0100] Energy density refers to the measure of how much energy a battery contains with respect to its mass or weight. In some aspects, the all-solid-state battery delivers a laboratory scale cell level energy density of at least about 180 Wh kg.sup.1 to about 300 Wh kg.sup.1 per mono cell.
[0101] Also described herein is a system comprising an all-solid-state battery of any one of the all-solid-state batteries described herein connected to an energy source or an electrical device.
[0102] Electric vehicles and portable electronics are example uses for embodiments of the high-voltage, sulfide-based, all solid-state batteries disclosed herein. Methods
[0103] Also described herein is a method of fabricating a cathode (e.g., a lithium-based cathode), comprising: providing a dispersion of an amphipathic binder, Li.sub.6PS.sub.5Cl, single-crystal LiNi.sub.0.8Mn.sub.0.1Co.sub.0.1O.sub.2 coated with Li.sub.2SiO.sub.x wherein x is about 1 to about 3 in a solvent; and vacuum filtering the dispersion through a filter, thereby forming a layer of lithium-based cathode.
[0104] In some aspects, the method further comprises removing the layer of cathode (e.g., lithium-based cathode) from the filter to form a freestanding layer of cathode (e.g., lithium-based cathode). In some aspects, the method further comprises evaporating the solvent from the layer of cathode (e.g., lithium-based cathode) or freestanding layer of cathode (e.g., lithium-based cathode).
[0105] Examples of organic solvents include: alkyl solvents (such as hexanes, cyclohexane, pentanes, and the like), aromatic solvents (such as xylene, benzene, toluene, and the like), alcohols (such as acidic methanol, ethanol, and the like), esters, ethers, and ketones (such as diethyl ether, acetone, and the like), amines (such as dimethyl amine and the like), and nitrated and halogenated hydrocarbons (such as dichloromethane, acetonitrile, and the like), and polar aprotic solvents (such as 1-methyl-2-pyrrolidone (sometimes referred to herein as N-methylpyrrolidone, NMP), dimethylsulfoxide (DMSO), dimethylformamide (DMF) and the like). In some aspects, the organic solvent comprises a polar aprotic solvent (such as NMP, DMSO, DMF, and the like). In some aspects, the organic solvent comprises an aromatic solvent, such as an aromatic hydrocarbon solvent. In some aspects, the organic solvent comprises xylene or toluene, or a combination thereof.
[0106] In some aspects, the amphipathic binder is an alkyl cellulose, such as methyl cellulose or ethyl cellulose. In some aspects, the amphipathic binder is ethyl cellulose.
[0107] In some aspects, the amphipathic binder is about 1.0 weight percent (wt. %) to about 3.0 wt. % of the dispersion. In some aspects, the amphipathic binder is about 1.0 weight percent (wt. %) to about 2.0 wt. % of the dispersion. In some aspects, the amphipathic binder is about 1.0 weight percent (wt. %) to about 1.5 wt. % of the dispersion. In some aspects, the amphipathic binder is about 1.0 wt. % of the dispersion.
[0108] Also described herein is a method of fabricating an anode, comprising: providing a dispersion of an amphipathic binder, Si, Li.sub.6PS.sub.5Cl, and carbon black in a solvent; and vacuum filtering the dispersion through a filter, thereby forming a layer of anode.
[0109] In some aspects, the method further comprises removing the layer of anode from the filter to form a freestanding layer of anode.
[0110] In some aspects, the method further comprises evaporating the solvent from the layer of anode or freestanding layer of anode. In some aspects, the solvent is an organic solvent as described above.
[0111] In some aspects, the amphipathic binder is a binder as described above. In some aspects, the amphipathic binder is ethyl cellulose. In some aspects, the amphipathic binder is about 1.0 wt. % to about 5.0 wt. % of the dispersion. In some aspects, the amphipathic binder is about 2.0 wt. % to about 5.0 wt. % of the dispersion. In some aspects, the amphipathic binder is about 3.0 wt. % to about 5.0 wt. % of the dispersion. In some aspects, the amphipathic binder is about 3.5 wt. % to about 4.5 wt. % of the dispersion. In some aspects, the amphipathic binder is about 4.0 wt. % of the dispersion.
[0112] Without wishing to be bound by any particular theory, it is believed that the vacuum filtration approach to fabricating electrodes described herein enabled the formation of dense, freestanding electrodes, and minimized pores, such as solvent pores resulting from evaporation of solvent from electrodes produced by traditional cast and coat techniques.
[0113] Also described herein is a method of fabricating the all-solid-state battery described herein, the method comprising stacking freestanding layers of the cathode (e.g., the lithium-based cathode), the sulfide solid electrolyte, the anode, and the current collector in a bipolar design, and pressing the layers together to form the all-solid-state battery. The method of fabricating an all-solid-state battery can further comprise any of the methods described herein for fabricating a cathode and/or anode described herein.
[0114] In some aspects, pressing the layers together comprises applying a pressure of about 3 MPa to about 100 MPa to the layers. In some aspects, pressing the layers together comprises applying a pressure of about 50 MPa to the layers.
[0115] As used herein, the term bipolar design or bipolar stacking refers to a configuration for a battery pack or an all-solid-state battery where the mono cells are connected in series through one current collector contacting two electrodes without external connections.
EXEMPLIFICATION
[0116] Compared to the lithium-ion batteries using organic liquid electrolyte, all solid-state lithium batteries (ASLBs) have the advantages of improved safety and higher energy density. Multilayered bipolar stacking in ASLBs can further improve the energy density by minimizing the use of inactive materials. However, it is highly challenging to fabricate bipolar stacked ASLBs because of lacking vigorous laminated electrodes and electrolyte, especially for sulfide solid electrolytes. This work successfully assembled bipolar stacked ASLBs with high voltage by facilely stacking freestanding and robust cathode, electrolyte, and anode sheets. More specifically, interface stabilized single-crystal LiNi.sub.0.8Mn.sub.0.1Co.sub.0.1O.sub.2, Li.sub.6PS.sub.5Cl, and nano Si act as cathode, electrolyte, and anode individually. Amphipathic ethyl cellulose plays a role as disperser during ink preparation and further as binder in the freestanding membrane. The doubly stacked ASLBs deliver a high voltage of 8.2 V and cell-level energy density of 204 Wh kg.sup.1 higher than the 189 Wh kg.sup.1 of the mono cell. In practical application, the energy density can be further effectively boosted by stacking multiple cells.
[0117] The following data has been published in Cao, D.; Sun, X.; Wang, Y.; Zhu, H., Bipolar stackings high voltage and high cell level energy density sulfide based all-solid-state batteries, Energy Storage Materials 2022, 48, 458-465, the entire content of which is incorporated herein by reference.
Example 1: Design of Bipolar Stacked ASLBs
[0118] Robust electrodes and SE layers play important roles in bipolar stacked ASLBs fabrication. The electrodes and SE layers used for bipolar stacked ASLBs should have high integrity, well-controlled layer thickness/mass, and high robustness to benefit the stacking of many cells. However, in most studies on sulfide SEs, cold pressing is used to make thick pallets of electrode and SE, which have several limitations, including: difficulty obtaining a thin and uniform membrane resulting in an easy internal short circuit when stacking multiple cells; cold-pressed SE layers have high thickness/mass causing a limited cell-level energy density; size limitations; and any inconsistencies in each cell in bipolar stacked ASLBs highly determines the cycling stability and life. Meanwhile, it is challenging to accurately control each cell's consistency through cold pressing.
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Example 2: Characterization of Cathode Layer
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[0122] The electrochemical performance of the cathode layer was evaluated in a half cell with In-Li as the anode.
[0123] Then the rate performance of the cathode layer was investigated, as shown in
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Example 3: Characterization of Anode Layer
[0125] The anode layer was also investigated.
[0126] The electrochemical performance of the anode layer was investigated in the half-cell.
Example 4: Characterization of the Mono Cell
[0127] Then the mono cell was assembled by facilely stacking the SS current collector, cathode layer, SE layer, and anode layer one by one, as illustrated in
[0128] The mono cell was cycled at C/10 in the voltage range from 2.25 to 4.1 V. The n/p ratio was 1.45, calculated based on the half-cell performance.
TABLE-US-00001 TABLE 1 Parameters for the gravimetric energy density calculation of the mono cell. Cathode (mg) 31.5 Cathode active material (mg) 25 Anode (mg) 5 Anode active material (mg) 3 Solid state electrolyte layer (mg) 10 Cell area (cm.sup.2) 1.26 Specific capacity.sub.CAM (mAh g.sup.1) 150 Average voltage (V) 3.28 Stainless steel current collector (mg) 9.5 Gravimetric energy density (without current 266 collector) (Wh kg.sup.1) Gravimetric energy density (with current collector) 189 (Wh kg.sup.1)
[0129] Example 5: Characterization of Bipolar Stacked ASLB
[0130] The freestanding electrodes and SE layers enabled the successful assembly of batteries series with a bipolar design. As shown in
[0131]
[0132] The rate performance was also evaluated. As shown in
[0133] The advance of the bipolar cell was evident when increasing the number of stacked cells. The cell level gravimetric energy densities of the ASLBs with bipolar stacking and conventional stacking were evaluated in
TABLE-US-00002 TABLE 2 Gravimetric energy density evaluation of ASLBs with the bipolar stacking and conventional stacking. Cell number Bipolar stacking Conventional stacking 1 189.173 189.173 2 203.9546 189.173 3 209.4089 189.173 4 212.2469 189.173 5 213.9869 189.173 6 215.1628 189.173 7 216.0108 189.173 8 216.6511 189.173 9 217.1518 189.173 10 217.554 189.173
TABLE-US-00003 TABLE 3 Performance comparison with reported serially bipolar stacked ASLBs using sulfide SEs. Mono cell Energy Cathode Anode Cell Cycle voltage density active active No. numbers life (V) (Wh kg.sup.1) SE material material Ref. 1 2 30 4.1 204 Li.sub.6PS.sub.5Cl- NMC 811 Si This Ethyl work cellulose 2 2 1 3 44 Li.sub.3PS.sub.4 LCO LTO 28 3 3 1 4.2 N/A -Li.sub.3PS.sub.4 NMC 622 Li 29
Example 6: Summary
[0134] In summary, higher energy density all solid-state batteries based on sulfide electrolyte were developed by employing high energy electrodes and unique bipolar stacking. In contrast to the conventional LiBs sealed separately and then packed together, the solid electrolyte (SE) enabled ASLBs to be directly connected without extra packing materials. The bipolar stacking design minimized the amount of inactive material in the batteries resulting in a significantly increased energy density. Moreover, since the batteries were connected in series, the high voltage output was obtained. Also, the shortened electron conduction paths between cells benefit lower resistance and increased power density.
[0135] Freestanding cathode, SE, and anode layers were fabricated through a facile vacuum filtration method based on an ethyl cellulose-toluene system. The cathode and anode layers showed considerable tensile strengths of 347 and 562 kPa, respectively, benefiting the fabrication of bipolar stacked ASLBs through facilely pressing the uniaxially stacked electrodes, SE, and current collector layers. A Li.sub.2SiO.sub.x coated single-crystal LiNi.sub.0.8Mn.sub.0.1Co.sub.0.1O.sub.2 and nano Si worked as the cathode and anode active material, respectively. Both cathode and anode delivered remarkable capacities. When coupled the cathode and anode layers in a mono cell, a cell-level high energy density of 189 Wh kg.sup.1 (including current collectors) was obtained. In the bipolar-stacked double cell, the energy density was enhanced to 204 Wh kg.sup.1. This work sheds light on the significance of the bipolar design for ASLBs and accelerates the commercialization of ASLBs.
Example 7. Preparation of LiPSsCl
[0136] As synthesized Li.sub.6PS.sub.5C1 was dispersed in toluene and ball milled for 5 hours at 400 rpm. The toluene was removed in vacuum. After that, a 200 C. heat treatment was applied to totally remove the toluene. The fine Li.sub.6PS.sub.5Cl powders were successfully prepared.
Example 8: Li.SUB.2.SiO.@S-NMC
[0137] The Li.sub.2SiO.sub.x@S-NMC was prepared through a sol gel method. Tetraethyl orthosilicate (TEOS, Sigma-Aldrich, 99.0%), Lithium (Li, Sigma-Aldrich, 99.9%), anhydrous ethanol (Sigma-Aldrich), and single-crystal NMC 811 (Nanoramic Inc.) were utilized as received. 3.1 mg of Li was added in 1.2 mL ethanol. After all Li was consumed, 50 L of TEOS was added with stirring for 10 min at 300 rpm. Then 1 g of S-NMC powder was added in the solutions with stirring for 1 hour at 300 rpm. The ethanol was removed in a vacuum, and a bath sonication was applied to avoid the aggregation of S-NMC. The dried sample was then heated at 350 C. for 2 hours in a muffle furnace with ambient air. The Li.sub.2SiO.sub.x@S-NMC was collected and stored in the glovebox for further use.
Example 9: Preparation of Cathode Layer
[0138] The cathode layer was prepared through a vacuum filtration method in the glovebox. 3 mg of ethyl cellulose (Sigma-Aldrich) was dissolved in 2 mL of toluene at 50 C. Then 60 mg Li.sub.6PS.sub.5C1 powders were added with stirring for 1 hour at 300 rpm. After the Li.sub.6PS.sub.5C1 was well dispersed, 237 mg of Li.sub.2SiO.sub.x@S-NMC was added with stirring for 1 hour at 300 rpm. The dispersion was then cast in the vacuum filtration system with a diameter of 47 mm. After the visible solvent was removed, a freestanding thin membrane could then be peeled off from the filter paper. The membrane was then heated at 150 C. for 12 hours to totally remove the residual toluene. The cathode layer was obtained.
Example 10: Preparation of Anode Layer
[0139] The anode layer was fabricated with similar method as the cathode layer preparation. 180 mg of Si powder, 90 mg of Li.sub.6PS.sub.5Cl, and 30 mg of carbon black were mixed in an Argon-filled milling jar (50 mL) at 300 rpm for 5 hours. 2 g of ZrO2 milling balls (4 mm in diameter) were utilized. The Si-SE-CB was obtained. 3 mg of ethyl cellulose was first dissolved in 2 mL of toluene at 50 C. Then 72 mg of Si-SE-CB was added with continuous stirring for 1 hour at 300 rpm. The dispersion was then cast on the vacuum filtration system. The freestanding anode layer was finally obtained after peeling off from the filter paper and heated at 150 C. for 12 hours.
Example 11: Materials Characterization
[0140] The XRD was performed on PANalytical/Philips X'Pert Pro (PANalytical, Netherlands) with Cu Ka radiation. A Kapton tape was used to seal the sample. The SEM and EDX mapping were conducted on SEM JEOL JSM 7000F (JEOL Ltd., Japan). The tensile strength was measured on a HR 30 Discovery Hybrid Rheometer-dynamic mechanical analysis (DMA) (TA Instruments, USA). The cathode and anode layers were cut into strips with lengths of 3 cm and widths of 5 mm. The displacement speed was 0.01 mm s.sup.1.
Example 12: Fabrication of Half-Cell
[0141] All the cells were fabricated in a homemade pressurized cell. For the half cell, 200 mg Li.sub.6PS.sub.5Cl was placed in a PEEK-made mold and applied a pressure of 300 MPa. Then one piece of electrode (cathode or anode) layer was placed on one side, and a piece of In-Li foil was attached in the other side. The cell was then pressed at the pressure of 100 MPa. Cu foil was used as the current collector for both sides. An external pressure of 50 MPa was applied to the cell during cycling.
Example 13: Fabrication of Full Cell
[0142] The full cell was assembled in a similar method with half-cell. For the mono cell, stainless steel foil, cathode layer, SE layer, anode layer and stainless steel foil were stacked in sequence in a PEEK-made mold. Then an axial pressure of 300 MPa was applied to the cell for 10 min. An external pressure of 50 MPa was applied in the cell during cycling. For the doubly stacked cells, stainless steel foil, cathode layer, SE layer, anode layer, stainless steel foil, cathode layer, SE layer, anode layer, and stainless steel foil were stacked in the mold in sequence. After a pressure of 300 MPa was applied, the bipolar stacked ASLBs were successfully assembled.
Example 14: Electrochemical Measurement
[0143] The anode half-cell was measured in a galvanostatic charge/discharge at current density of 0.1, 0.2, 0.5, 1, and 2 mA cm.sup.2 in the voltage range between 0.6 to 0.9 V (vs. In-Li). The mass loading was around 4 mg cm.sup.2. The cathode half-cell was measured in a protocol that the cell was charged at constant current to 3.8 V (vs. In-Li), held at 3.8 V for 1 h, then discharged to 2.0 V (vs. In-Li). The current was set based on the theoretical capacity of NMC for 200 mAh g.sup.1. The mono cell was measured in a similar way in that the cell was charged at constant current to 4.1 V, held at 4.1 V for 1 h, then discharged to 2.25 V. The current was set based on the theoretical capacity of NMC for 200 mAh g.sup.1. The bipolar stacked double-layer cell was charged at constant current to 8.2 V, held at 8.2 V for 1 h, then discharged to 4.5 V. The current was set based on the theoretical capacity of NMC for 200 mAh g.sup.1.
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[0173] The teachings of all patents, published applications, and references cited herein are incorporated by reference in their entirety.
[0174] While example embodiments have been particularly shown and described, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the embodiments encompassed by the appended claims.