This application claims the benefit of Chinese Patent Application No. 202310114228.2, filed on Feb. 14, 2023. The entire disclosure of the application referenced above is incorporated herein by reference.
The information provided in this section is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
The present disclosure relates to battery cells, and more particularly to silicon-based solid-state batteries.
Electric vehicles (EVs) such as battery electric vehicles (BEVs), hybrid vehicles, and/or fuel cell vehicles include one or more electric machines and a battery system including one or more battery cells, modules, and/or packs. A power control system is used to control charging and discharging of the battery system during charging and/or driving. Manufacturers of EVs are pursuing increased energy density to increase the range of the EVs.
Solid-state batteries (SSBs) with solid electrolyte and SSBs with sulfide electrolyte have the potential to be superior to various different types of lithium-ion batteries (LIBs) in terms of abuse tolerance, working temperature range, and system design.
A battery cell including an anode electrode layer including an anode active material. A cathode electrode layer comprises cathode active material. A solid electrolyte layer is arranged between the anode electrode layer and the cathode electrode layer. An elastomeric layer is arranged between the anode electrode layer and the solid electrolyte layer.
In some examples, the elastomeric layer comprises an elastomer matrix and a lithium-ion conducting medium. The elastomer matrix includes one or more materials selected from a group consisting of an acrylic-based elastomer, natural rubber, polyisoprene, butyl rubber, chloroprene, ethylene propylene diene, fluorosilicone, nitrile butadiene, saturated nitrile rubber, silicone rubber, styrene butadiene rubber, and urethane. The lithium-ion conducting medium comprises at least one of a lithium salt and a solid electrolyte.
In other features, the lithium salt comprises a lithium cation and at least one anion selected from a group consisting of hexafluoroarsenate, hexafluorophosphate, perchlorate, tetrafluoroborate, vis(oxalate)borate (BOB), bis(fluorosulfonyl)imide (FSI), bis(trifluoromethanesulfonyl)imide (TFSI), cyclo-difluoromethane-1,1-bis(sulfonyl)imide (DMSI), bis(perfluoroethanesulfonyl)imide (BETI), difluoro(oxalato)borate (DFOB), and bis(fluoromalonato)borate (BFMB).
In other features, the solid electrolyte includes one or more materials selected from a group consisting of oxide-based solid electrolyte, metal-doped or aliovalent-substituted oxide solid electrolyte, sulfide-based solid electrolyte, nitride-based solid electrolyte, hydride-based solid electrolyte, halide-based solid electrolyte, and borate-based solid electrolyte. The elastomeric layer further comprises a plasticizer. The plasticizer is selected from a group consisting of an ether, a nitrile, a carbonate solvent, a lactone, a sulfone, a phosphate, and an ionic liquid.
In other features, the anode electrode layer comprises an anode active material, a solid electrolyte, and a binder comprising an elastomer matrix and a lithium-ion conducting medium. The binder further comprises a plasticizer. The elastomeric layer comprises an elastomer matrix and a lithium-ion conducting medium. The anode electrode layer comprises the anode active material, a solid electrolyte, and a binder comprising an elastomer matrix and a lithium-ion conducting medium.
In other features, the cathode electrode layer comprises a cathode active material, a solid electrolyte, a conductive additive, and a binder. The cathode active material includes one or more materials selected from a group consisting of rock salt layered oxides, spinel, polyanion cathode materials, lithium transition-metal oxides, and lithiated metal oxide/sulfide. The anode active material includes one or more materials selected from a group consisting of silicon, silicon mixed with graphite, Li4Ti5O12, a transition-metal, a Li metal, and a Li alloy.
In other features, the conductive additive is selected from a group consisting of carbon black, graphite, graphene, graphene oxide, Super P, acetylene black, carbon nanofibers, and carbon nanotubes. The binder is selected from a group consisting of poly(vinylidene fluoride) (PVDF), poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP), poly(tetrafluoroethylene) (PTFE), sodium carboxymethyl cellulose (CMC), styrene-butadiene rubber (SBR), nitrile butadiene rubber (NBR), and styrene ethylene butylene styrene copolymer (SEBS).
A battery cell includes an anode electrode layer including anode active material comprising anode active material, a solid electrolyte, and a binder comprising an elastomer matrix and a lithium-ion conducting medium. A cathode electrode layer comprises cathode active material. A solid electrolyte layer is arranged between the anode electrode layer and the cathode electrode layer.
In other features, the binder further comprises a plasticizer. The elastomer matrix includes one or more materials selected from a group consisting of an acrylic-based elastomer, natural rubber, polyisoprene, butyl rubber, chloroprene, ethylene propylene diene, fluorosilicone, nitrile butadiene, saturated nitrile rubber, silicone rubber, styrene butadiene rubber, and urethane. The lithium-ion conducting medium comprises at least one of a lithium salt and a solid electrolyte. The lithium salt comprises a lithium cation and at least one anion selected from a group consisting of hexafluoroarsenate, hexafluorophosphate, perchlorate, tetrafluoroborate, vis(oxalate)borate (BOB), bis(fluorosulfonyl)imide (FSI), bis(trifluoromethanesulfonyl)imide (TFSI), cyclo-difluoromethane-1,1-bis(sulfonyl)imide (DMSI), bis(perfluoroethanesulfonyl)imide (BETI), difluoro(oxalato)borate (DFOB), and bis(fluoromalonato)borate (BFMB). The solid electrolyte includes one or more materials selected from a group consisting of oxide-based solid electrolyte, metal-doped or aliovalent-substituted oxide solid electrolyte, sulfide-based solid electrolyte, nitride-based solid electrolyte, hydride-based solid electrolyte, halide-based solid electrolyte, and borate-based solid electrolyte.
In other features, the plasticizer is selected from a group consisting of an ether, a nitrile, a carbonate solvent, a lactone, a sulfone, a phosphate, and an ionic liquid.
Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims, and the drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.
The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:
In the drawings, reference numbers may be reused to identify similar and/or identical elements.
While the battery cells are described herein in the context of electric vehicles (EVs), the battery cells can be used in stationary applications, non-vehicle applications, and/or in other applications.
Silicon has emerged as a promising alternative to graphite-based anode electrodes for solid-state batteries because it is environmentally benign, has reasonable electrochemical potential (˜0.3 Volts vs Li/Li+), and a high theoretical capacity (4200 milliamp hours per gram (mAh/g) for Li4.4Si). However, Si anode electrodes may suffer from volumetric expansion (e.g., >300%) during charging. The significant volume expansion and shrinkage creates mechanical stresses, which may cause cracking and/or pulverization of Si and may deteriorate ionic interfaces between the solid electrolyte layer and the Si anode electrode layer. As a result, the battery capacity may decay.
An elastomeric layer according to the present disclosure includes an elastomer matrix and a lithium (Li)-ion conducting medium. For example, the elastomer matrix comprises poly-butyl acrylate (PBA) cross-linked by poly(ethylene glycol) diacrylate (PEGDA)) and the Li-ion conducting medium includes LiTFSI (bis(trifluoromethane)solfonimide). The elastomeric layer is arranged between a solid electrolyte layer and a silicon (Si) anode electrode layer in a solid-state battery (SSB).
The mechanical elasticity of the elastomeric layer helps to release stress generated during charging and discharging. In other words, the elastomeric layer accommodates volume change of the Si active material and minimizes possible structural changes in the Si anode electrode layer. Adhesion properties of the elastomeric layer may maintain interfacial ionic contact between the solid electrolyte layer and the Si anode electrode layer.
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In some examples, the elastomer matrix comprises poly(butyl acrylate) (PBA) cross-linked by 1 mol % poly(ethylene glycol) diacrylate (PEGDA). In some examples, an average molecular weight (MW) is in a range from approximately 1000 to approximately 999,000 (e.g., 99,000). In some examples, the elastomer matrix has a density ρ in a range from approximately 0.90 to approximately 1.50 (e.g., 1.09 gras per milliliter (g/mL) at 25° C.). In some examples, the Li-ion conducting medium comprises a lithium salt such as LiTFSI in a range from approximately 0.01 M to approximately 5M (e.g., 0.8M).
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In other examples, the elastomeric layer and/or the elastomeric material in the binder includes plasticizer. Referring now to
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In some examples, the Li-ion conducting medium is compatible and dispersible within an elastomer matrix. In some examples, the Li-ion conducting medium includes at least one of a lithium salt and a solid electrolyte. In some examples, the lithium salt includes a lithium cation and at least one anion selected from a group including or consisting of hexafluoroarsenate, hexafluorophosphate, perchlorate, tetrafluoroborate, vis(oxalate)borate (BOB), bis(fluorosulfonyl)imide (FSI), bis(trifluoromethanesulfonyl)imide (TFSI), cyclo-difluoromethane-1,1-bis(sulfonyl)imide (DMSI), bis(perfluoroethanesulfonyl)imide (BETI), difluoro(oxalato)borate (DFOB), and bis(fluoromalonato)borate (BFMB).
In some examples, the solid electrolyte includes one or more materials selected from a group including or consisting of oxide-based solid electrolyte, metal-doped or aliovalent-substituted oxide solid electrolyte, sulfide-based solid electrolyte, nitride-based solid electrolyte, hydride-based solid electrolyte, halide-based solid electrolyte, and borate-based solid electrolyte.
Examples of oxide-based solid electrolyte include garnet type (e.g., Li7La3Zr2O12). Perovskite type (e.g., Li3xLa2/3−xTiO3), NASICON type (e.g., Li1.4Al0.4Ti1.6(PO4)3and Li1+xAlxGe2−x(PO4)3), and LISICON type (e.g., Li2+2xZn1−xGeO4). Examples of metal-doped or aliovalent-substituted oxide solid electrolyte include Al (or Nb)-doped Li7La3Zr2O12, Sb-doped Li7La3Zr2O12 , Ga-substituted Li7La3Zr2O12, Cr and V-substituted LiSn2P3O12, Al-substituted perovskite, Li1+x+yAlxTi2−xSiyP3−yO12.
In some examples, the sulfide electrolyte is selected from a group including or consisting of pseudobinary sulfide, pseudoternary sulfide, and pseudoquarternary sulfide. Examples of pseudobinary sulfide include Li2S—P2S5 system (Li3PS4, Li7P3S11 and Li9.6P3S12), Li2S—SnS2 system (Li4SnS4), Li2S—SiS2 system, Li2S—GeS2 system, Li2S—B2S3 system, Li2S—Ga2S3 system, Li2S—P2S3 system, Li2S—Al2S3 system. Examples of pseudoternary sulfide. e.g., Li2O—Li2S—P2S5 system, Li2S—P2S5−P2O5 system, Li2S—P2S5—GeS2 system (Li3.25Ge0.25P0.75S4 and Li10GeP2S12), Li2S—P2S5—LiX (X=F, Cl, Br, I) system (Li6PS5Br, Li6PS5Cl, L7P2S8I and Li4PS4I), Li2S—As2S5—SnS2 system (Li3.833Sn0.833As0.166S4), Li2S—P2S5—Al2S3 system, Li2S—LiX—SiS2 (X=F, Cl, Br, I) system, 0.4LiI.0.6Li4SnS4 and Li11Si2PS12. Examples of pseudoquaternary sulfide include Li2O—Li2S—P2S5—P2O5 system, Li9.54Si1.74P1.44S11.7Cl0.3, Li7P2.9Mn0.1S10.7I0.3, and Li10.35[Sn0.27Si1.08]P1.65S12.
Examples of nitride-based solid electrolyte include Li3N, Li7PN4, and LiSi2N3. Examples of hydride-based solid electrolyte include LiBH4, LiBH4—LiX (X=Cl, Br or I), LiNH2, Li2NH, LiBH4—LiNH2, and Li3AlH6. Examples of halide-based solid electrolyte include LiI, Li3InCl6, Li2CdCl4, Li2MgCl4, Li2CdI4, Li2ZnI4, and Li3Ocl. Examples of borate-based solid electrolyte include Li2B4O7 and Li2O—B2O3—P2O5
In some examples, the elastomer matrix disperses the Li-ion conducting medium while maintaining both mechanical elasticity and functionality. In some examples, the elastomer matrix includes one or more materials selected from a group including or consisting of acrylic-based elastomers (e.g., poly(butyl acrylate), poly(n-butyl acrylate)-g-polyacrylonitrile), natural rubber, polyisoprene, butyl rubber, chloroprene, ethylene propylene diene, fluorosilicone, nitrile butadiene, saturated nitrile rubber, silicone rubber, styrene butadiene rubber, and urethane (e.g., polyurethane).
In some examples, the anode and cathode electrodes include electrode active material, solid electrolyte, conductive additive, and binder. In some examples, the anode and cathode electrodes have a thickness in a range from approximately 1 micrometers (μm) to approximately 400 μm. In some examples, the electrode active material includes approximately 30 wt % to 98 wt %, the solid electrolyte includes approximately 0 wt % to 50 wt %, the conductive additive includes approximately 0 wt % to 30 wt %, and the binder includes 0.1 wt % to 20 wt %. In various implementations, a sum of the wt % of the electrode active material, the solid electrolyte, the conductive additive, and the binder may be 100 wt %.
In some examples, the cathode active material includes one or more materials selected from a group including or consisting of rock salt layered oxides, spinel, polyanion cathode materials, lithium transition-metal oxides, and lithiated metal oxide/sulfide. In some examples, surface-coated or doped rock salt layered oxides, spinel, polyanion cathode materials, and lithium transition-metal oxides are used.
Examples of rock salt layered oxides include LiCoO2, LiNixMnyCo1−x−yO2, LiNixMnyAl1−x−yO2, LiNixMn1−xO2, Li1+xMO2. Examples of spinel includes LiMn2O4, and LiNi0.5Mn1.5O4. Examples of polyanion cathode include LiV2(PO4)3. Examples of surface-coated and/or doped cathode materials include LiNbO3-coated LiMn2O4, and Al-doped LiMn2O4. Examples of lithiated metal oxide/sulfide LiTiS2, lithium sulfide, and sulfur.
In some examples, the anode active materials include one or more materials selected from a group consisting of silicon, silicon mixed with graphite, Li4Ti5O12, transition-metal (e.g., Sn), Li metal and Li alloy.
In some examples, the binder is selected from a group consisting of poly(vinylidene fluoride) (PVDF), poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP), poly(tetrafluoroethylene) (PTFE), sodium carboxymethyl cellulose (CMC), styrene-butadiene rubber (SBR), nitrile butadiene rubber (NBR), and styrene ethylene butylene styrene copolymer (SEBS).
In some examples, the conductive additive is selected from a group consisting of carbon black, graphite, graphene, graphene oxide, Super P, acetylene black, carbon nanofibers, carbon nanotubes and other electronically conductive additives.
In some examples, the plasticizer is selected from a group including or consisting of an ether, a nitrile, a carbonate solvent, a lactone, a sulfone, a phosphate, and an ionic liquid.
Examples of ethers include triethylene glycol dimethylether (triglyme, G3), tetraethylene glycol dimethylether (tetraglyme, G4), 1,3-dimethoxy propane and 1,4-dioxane. Examples of nitriles include succinonitrile, glutaronitrile and adiponitrile. Examples of carbonate solvents include ethylene carbonate (EC), propylene carbonate (PC), glycerol carbonate, vinylene carbonate, fluoroethylene carbonate and 1,2-Butylene carbonate. Examples of lactones include γ-butyrolactone and δ-valerolactone. Examples of sulfones include tetramethylene sulfone, ethyl methyl sulfone, vinyl sulfone, phenyl sulfone, 4-fluorophenyl sulfone and benzyl sulfone. Examples of phosphates include triethyl phosphate and trimethyl phosphate.
Examples of ionic liquids include ionic liquid cations and ionic liquid anions. Examples of ionic liquid cations include 1-Ethyl-3-methylimidazolium, 1-Propyl-1-methylpiperidinium, 1-Butyl-1-methylpiperidinium, 1-Methyl-1-ethylpyrrolidinium, 1-Propyl-1-methylpyrrolidinium, 1-Butyl-1-methylpyrrolidinium. Examples of ionic liquid anions include bis(fluorosulfonyl)imide (FSI) and bis(trifluoromethanesulfonyl)imide (TFSI).
The foregoing description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure. Further, although each of the embodiments is described above as having certain features, any one or more of those features described with respect to any embodiment of the disclosure can be implemented in and/or combined with features of any of the other embodiments, even if that combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and permutations of one or more embodiments with one another remain within the scope of this disclosure.
Spatial and functional relationships between elements (for example, between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including “connected,” “engaged,” “coupled,” “adjacent,” “next to,” “on top of,” “above,” “below,” and “disposed.” Unless explicitly described as being “direct,” when a relationship between first and second elements is described in the above disclosure, that relationship can be a direct relationship where no other intervening elements are present between the first and second elements, but can also be an indirect relationship where one or more intervening elements are present (either spatially or functionally) between the first and second elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”
In the figures, the direction of an arrow, as indicated by the arrowhead, generally demonstrates the flow of information (such as data or instructions) that is of interest to the illustration. For example, when element A and element B exchange a variety of information but information transmitted from element A to element B is relevant to the illustration, the arrow may point from element A to element B. This unidirectional arrow does not imply that no other information is transmitted from element B to element A. Further, for information sent from element A to element B, element B may send requests for, or receipt acknowledgements of, the information to element A.
Number | Date | Country | Kind |
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202310114228.2 | Feb 2023 | CN | national |