SOLID-BODY BATTERIES

Abstract

A solid-state battery cell comprises A anode electrodes with an anode active material layer arranged on an anode current collector, and C cathode electrodes with a cathode active material layer arranged on a cathode current collector. The cathode active material layer comprises cathode active material with particles that include an outer layer of a material selected from the group consisting of LiNbO3, Li2ZrO3, Li3PO4, and combinations thereof. A solid electrolyte has a D50 size in the range of 4 µm to 12 µm. S separators are arranged between the A anode electrodes and the C cathode electrodes, where A, C, and S are integers greater than one.

Description

INITIATIONThe information included in this section serves to generally illustrate the context of the disclosure. Work of the present inventors, insofar as described in this section, as well as aspects of the description that may not be prior art at the time of filing, are neither expressly nor silently accepted as prior art against the present disclosure.The present disclosure relates to battery cells, and more particularly to high performance cathode electrodes for solid state batteries.Electric vehicles (EVs), such as battery-powered electric vehicles (BEVs), hybrid vehicles, and / or fuel cell vehicles, include one or more electric machines and a battery system having one or more battery cells, modules, and / or packs. A power control system is employed to control charging and / or discharging of the battery system during charging and / or driving.SUMMARYAn all-solid-state battery cell includes A anode electrodes having an anode active material layer disposed on an anode current collector, C cathode electrodes having a cathode active material layer disposed on a cathode current collector. The cathode active material layer comprises cathode active material having particles comprising an outer layer of a material selected from a group consisting of LiMnO 3, Li 2 ZrO 3, Li 3 PO 4 and combinations thereof. A solid electrolyte has a D 50- size in a range of 4 μm to 12 μm. Between the A anode electrodes and the C cathode electrodes, S separators are disposed, where A, C, and S are integers greater than one.In other cases, the particles comprise lithium nickel cobalt manganese (NMC) particles and the outer layer LiMnO 3. The NMC particles have a diameter of 2 μm<D 50< 5 μm. Nickel comprises 50 to 72 mol % of the NMC particles, manganese comprises 8 to 40 mol % of the NMC particles, and cobalt comprises 10 to 20 mol % of the NMC particles. The outer layer has a thickness between 7 nm and 13 nm. The solid electrolyte in the cathode active material layer has a diameter D 90< 15 μm. The solid electrolyte includes a sulfidic solid electrolyte selected from a group consisting of pseudobinary sulfide, pseudoternar sulfide, and pseudoquaternary sulfide.In other cases, the solid electrolyte is selected from a group consisting of halide-based solid electrolytes and hydride-based solid electrolytes. The cathode active material is selected from a group formed from rock salt layered oxides, spinel, polyanion cathodes, olivine cathodes, other lithium transition metal oxides, surface coated and / or doped cathode materials, and combinations thereof. The cathode active material layer further comprises a conductive additive selected from a group consisting of carbon black, graphite, graphene, graphene oxide, Super P, acetylene black, carbon nanofibers, carbon nanotubes, and combinations thereof. The cathode active material layer further comprises a binder selected from a group consisting of polytetrafluoroethylene (PTFE), sodium carboxymethyl cellulose (CMC), styrene-butadiene rubber (SBR), poly(vinylidene fluoride) (PVDF), nitrile-butadiene rubber (NBR), styrene-ethylene-butylene-styrene copolymer (SEBS), styrene-butadiene-styrene copolymer (SBS), and combinations thereof.A dry method of making a cathode electrode for an all-solid-state battery cell includes mixing cathode active material comprising particles having an outer layer selected from a group consisting of LiMnO 3, Li 2 ZrO 3, Li 3 PO 4 and combinations thereof, and a solid electrolyte comprising particles having a D 50- size in a range from 4 μm to 12 μm. adding a binder and a conductive additive to the cathode active material and the solid electrolyte. coating a substrate with cathode active material, the solid electrolyte, the binder, and the conductive additive.In other features, the cathode active material is selected from a group consisting of rock salt layered oxides, spinel, polyanion cathodes, olivine cathodes, other lithium transition metal oxides, and surface coated and / or doped cathode materials. The solid electrolyte is selected from a group consisting of pseudobinary sulfide, pseudoternar sulfide, pseudoquaternary sulfide, a halide-based solid electrolyte, and a hydride-based solid electrolyte.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 formed from polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP) fibrils, perfluoroalkoxy alkane (PFA) fibrils, and / or ethylene tetrafluoroethylene (ETFE) fibrils.In other features, the cathode active material comprises lithium nickel cobalt manganese (NMC) particles having a diameter of 2 μm<D 50< 5 μm and the outer layer comprises LiMnO 3 having a thickness in the range of 7 nm to 13 nm. Nickel comprises 50 to 72 mol % of the NMC particles, Mn comprises 8 to 40 mol % of the NMC particles, and Co comprises 10 to 20 mol % of the NMC particles.A wet method of manufacturing a cathode electrode for an all-solid-state battery cell, in which a mixture is produced, comprising a cathode active material comprising particles having an outer layer selected from a group consisting of LiMnO 3, Li 2 ZrO 3, Li 3 PO 4 and combinations thereof, a solid electrolyte comprising particles having a D 50- size in a range from 4 μm to 12 μm, a binder, a conductive additive, and a solvent. The method comprises applying the mixture to a substrate.In other features, the cathode active material is selected from a group consisting of rock salt layered oxides, spinel, polyanion cathodes, olivine cathodes, other lithium transition metal oxides, and surface coated and / or doped cathode materials. The solid electrolyte is selected from a group consisting of pseudobinary sulfide, pseudoternar sulfide, pseudoquaternary sulfide, a halide-based solid electrolyte, and a hydride-based solid electrolyte.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 formed of sodium carboxymethyl cellulose (CMC), styrene-butadiene rubber (SBR), poly(vinylidene fluoride) (PVDF), nitrile-butadiene rubber (NBR), styrene-ethylene-butylene-styrene copolymer (SEBS), and styrene-butadiene-styrene copolymer (SBS).In other features, the cathode active material comprises lithium nickel cobalt manganese (NMC) particles having a diameter of 2 μm<D 50< 5 μm and the outer layer comprises LiMnO 3 having a thickness in the range of 7 nm to 13 nm. Nickel comprises 50 to 72 mol % of the NMC particles, manganese comprises 8 to 40 mol % of the NMC particles, and cobalt comprises 10 to 20 mol % of the NMC particles.Further areas of applicability of the present disclosure will become apparent from the detailed description, claims and 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.BRIEF DESCRIPTION OF THE DRAWINGSThe present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein: FIG. 1 is a side cross-sectional view of an example of an all-solid-state battery cell including cathode electrodes, anode electrodes, and separators disposed in a battery cell case according to the present disclosure; FIG. 2 is a more detailed side cross-sectional view of an example of an all-solid-state battery cell having cathode electrodes, anode electrodes, and separators according to the present disclosure; FIG. 3 is a side cross-sectional view of particles of the cathode active material having an outer layer of lithium niobate (LiNobO 3), lithium zirconate (Li 2 ZrO 3) and / or lithium phosphate (Li 3 PO 4) in accordance with the present disclosure; FIG. 4A is a graph depicting voltage as a function of capacitance for various sizes of solid electrolytes; FIG. 4B is a graph illustrating impedance for various sizes of solid electrolytes; FIG. 4C is a graph depicting capacitance as a function of cycles for various sizes of solid electrolytes; FIG. 5 is a flowchart illustrating an example of dry processing of the cathode electrodes according to the present disclosure; FIG. 6 is a flowchart illustrating an example of wet processing of the cathode electrodes according to the present disclosure; FIG. 7 illustrates enlarged views of the solid electrolyte and electrodes for different sizes of the solid electrolyte according to the present disclosure; and FIG. 8 is enlarged views illustrating the dispersion of the solid electrolyte in the cathode electrodes for different sizes of the solid electrolyte according to the present disclosure.In the drawings, reference numerals may be reused to identify similar and / or identical elements.DETAILED DESCRIPTIONWhile high power cathodes for solid state battery cells (SSB) according to the present disclosure are shown in the context of electric vehicles, the high power cathodes for solid state battery cells may be used in stationary applications and / or other applications.A sulfide electrolyte can provide an ionic conductivity comparable to that of carbonate-based electrolytes. However, the performance of a sulfide electrolyte composite cathode electrode is affected by the slow ion transport at the active material-solid electrolyte interface and the unfavourable ion conduction due to the poor percolation of the solid electrolyte within the electrode.A high-power cathode electrode for a pure solid-state battery (ASSB) according to the present disclosure includes single-crystal cathode particles including an outer layer with lithium niobate (LiMnO 3), lithium zirconate (Li 2 ZrO 3) and / or lithium phosphate (Li 3 PO 4) to prevent interfacial side reactions. The cathode particles are used with a solid electrolyte having a predetermined size to allow an efficient ion transport path within the cathode electrode. If the solid electrolyte particles in the cathode are too small, the solid electrolyte will have a strong percolation and a lower ion transport. Larger solid electrolyte particles have a higher porosity and a poorer percolation of the solid electrolyte. The thickness of the coating on the cathode particles is also matched to prevent chemical reactions (which occur without coating) and at the same time to optimize the lithium ion transport.The cathode electrode may include, for example, lithium nickel manganese cobalt (NMC) particles coated with a lithium niobate (LiMnO 3)- coating (e.g., 10 μm thick) to inhibit interfacial side reactions. For example, the size of the sulfide solid electrolyte particles (e.g., D 50= 8 μm) is selected to allow an efficient ion transport path within the cathode electrode. The high-power composite cathode electrode may provide, for example, a 3C discharge capacity of 88 mAh / g and a 5C discharge capacity of 74 mAh / g at 25° C.Referring now to FIG. 1, an all solid state battery cell 10 includes C cathode electrodes 20, A anode electrodes 40, and S separators 32 arranged in a predetermined order in a stack 12 in a case 50, where C, S, and A are integers greater than zero. The C cathode electrodes 20- 1, 20- 2,..., and 20- C include cathode active layers 24 disposed on one or both sides of the cathode current collectors 26. The A anode electrodes 40- 1, 40- 2,..., and 40 include anode active layers 42 disposed on one or both sides of the anode current collectors 46.In some examples, the anode active layers 42 and / or the cathode active layers 24 are free-standing electrodes disposed adjacent (or attached to) the current collectors. In some examples, the anode active layers 42 and / or the cathode active layers 24 comprise coatings having one or more active materials, one or more conductive fillers / additives, and / or one or more binders applied to the current collectors. In some examples, the cathode current collectors 26 and / or the anode current collectors 46 include wire mesh, foil, and / or expanded metal. In some examples, the current collectors are made of one or more materials selected from a group consisting of copper, stainless steel, brass, bronze, zinc, aluminum, and / or alloys thereof. The external tabs 28 and 48 may be connected to the current collectors of the cathode electrodes and anode electrodes on the same or opposite sides of the battery stack.Referring now to FIGS. 2 and 3, a more detailed example of the all solid state battery cell is shown. In FIG. 2, the cathode active material layer 24 includes cathode active material 210 and solid electrolyte 212 (e.g., sulfidic solid electrolyte). The separator 32 includes a solid electrolyte 220 (e.g., a sulfide solid electrolyte). The anode active material layer 40 includes anode active material 230 and solid electrolyte 232 (e.g., sulfidic solid electrolyte).In FIG. 3, the cathode active material 210 includes single crystal particles 250 of the cathode active material and an outer layer 252 deposited or otherwise applied to a radially outer surface of the particles 250. In some examples, the particles comprise 250 NMC or other cathode active material described below. In some examples, the outer layer 252 comprises lithium niobate (LiNbO 3), lithium zirconate (Li 2 ZrO 3) and / or lithium phosphate (Li 3 PO 4), although other materials may also be used. In some examples, the NMC particles 250 comprise 68 wt % to 92 wt % and the outer layer 8 wt % to 32 wt %. In some examples, the weight ratio between the particles 250 and the outer layer 252 is 70:30. in some examples, the coated NMC particles inhibit interfacial side reactions and the solid electrolyte allows efficient ion transport paths in the cathode electrode.In some examples, the particles 250 have a diameter of 2 μm<D 50< 5 μm (e.g., 3.8 μm). In some examples, the Brunauer, Emmett, and Teller (BET) surface area is in a range of 0.2 to 0.8 m 2 / g. In some examples, nickel (Ni) comprises 50 to 72 mol % of the NMC particles, manganese (Mn) comprises 8 to 40 mol %, and cobalt (Co) comprises 10 to 20 mol %. In some examples, the outer layer 252 has a thickness in the range of 7 nm to 13 nm (e.g., 10 nm). In some examples, the sulfide electrolyte 212 has a diameter of 4 μm<D 50< 12 μm (e.g., 8 μm) and D 90< 15 μm (e.g., 14.7 μm). In some examples, the sulfide electrolyte 212 has a diameter of 5 μm<D 50< 10 μm. The ionic conductivity is greater than 1 mS / cm.Referring now to Figures 4A-4C, the performance of the NMC particles with outer layers of different thicknesses is shown. In FIG. 4A, voltage is shown as a function of capacitance (mAh / g) for NMC without the outer layer (at 300), NMC with a 5 nm outer layer (at 305), NMC with a 10 nm outer layer (at 310), and NMC with a 15 nm outer layer (at 315). Some of the coated NMC examples (e.g., 5 nm and 10 nm coatings) exceed the uncoated NMC. In Figure 4B, the impedance of coated and uncoated NMC is shown. Some of the coated NMC examples (e.g., 5 nm and 10 nm coatings) have lower resistance.In Figure 4C, capacitance is shown as a function of cycles. Some of the coated NMC examples (e.g., 5 nm and 10 nm coatings) have a higher capacity than uncoated NMC. As can be seen, an electrochemically / chemically stable NMC / SE interface is made possible by the LiMnO 3- coating. NMC with the 10 nm coating has the lowest interfacial resistance with sulfide electrolyte.Referring now to FIG. 5, a method 400 for manufacturing a cathode electrode in a dry process is shown. At 410, coated cathode active material and solid sulfide electrolyte particles are mixed. At 414, a binder and a conductive additive are added to and mixed with the coated cathode active material and the sulfide solid electrolyte.At 416, the mixture is sheared (e.g., to fibrillate the binder) and pressed and / or rolled to form a free-standing cathode membrane. At 418, the membrane is attached to a cathode current collector. In some examples, one or more sets of rollers may be used to apply pressure and / or heat (or another device may be used). At 426, anode electrodes, the cathode electrodes, and separators are disposed in a battery cell.Referring now to FIG. 6, a method 500 of making a cathode electrode is shown. At 510, the coated cathode active material, the sulfide solid electrolyte, the solvent, the binder, and the conductive additive are mixed. At 514, the mixture is applied to a cathode current collector. At 518, the mixture is pressed and / or heated with a roller or other device to form the cathode electrode. At 522, the anode electrodes, the cathode electrodes, and the separators are disposed in a battery cell.Referring now to FIGS. 7 and 8, the influence of the size of the sulfide solid electrolyte is shown. In FIG. 7, enlarged views of the solid electrolyte and the cathode electrode are seen. When 5 μm and 8 μm are used, the closest packing of the cathode electrode is performed after pressing. Random sizes and larger sizes (e.g., 15 μm) have voids after pressing. In FIG. 8, the distribution of the sulfidic solid electrolyte is more uniform at 5 μm and 8 μm than at random or larger sizes (e.g., 15 μm).In some examples, the solid electrolyte comprises a sulfidic solid electrolyte selected from a group consisting of pseudobinary sulfide, pseudoternary sulfide, and pseudoquaternary sulfide. Examples of pseudobinary sulfides are the Li 2 S-P 2 S 5- system (Li 3 PS 4, Li 7 P 3 S 11 and Li 9,6 P 3 S12), the Li2S-SnS2 system (Li4SnS4), the Li2S-SiS2 system, the Li 2 S-GeS 2- system, the Li 2 S-B 2 S 3- system, the Li 2 S-Ga 2 S 3- system, the Li 2 S-P 2 S3 system, the Li2S-Al2S3 system, and combinations thereof.Examples of pseudoternary sulfides are the Li 2 O-Li 2 S-P 2 S 5- system, the Li 2 S-P 2 S 5- P 2 O 5- system, the Li 2 S-P 2 S 5- GeS 2- system (e.g., Li 3,25 Ge 0,25 P 0,75 S 4 and Li 10 GeP 2 S12), the Li2S-P2S5-LiX(X=F, Cl, Br, I) system (Li6PS5Br, Li 6 PS 5 Cl, L 7 P 2 S 8 I and Li 4 PS 4 I), the Li 2 S-As 2 S 5- SnS2system (Li3,833Sn0,833As0,166S4), the Li2S-P2S5Al2S3system, the Li 2 S-LiX-SiS 2( X=F, Cl, Br, I) system, 0.4Li-0.6Li 4 SnS 4, Li 11 Si 2 PS 12, and combinations thereof.Examples of pseudoquaternary sulfides include the Li 2 O-Li 2 S-P 2 S 5- P 2 O 5- system, Li 9,54 Si 1,74 P 1,44 S 1,7 Cl0,3, Li7P2,9Mn0,1S10,7I0,3, Li 10,35[ Sn 0,27 Si 1,08] P 1,65 S 12, and combinations thereof.In other examples, the solid electrolyte includes a halide-based solid electrolyte, a hydride-based solid electrolyte, or another solid electrolyte that has low grain boundary resistance. Examples of halide-based solid electrolyte, for example, Li 3 YCI 6, Li 3 InCl 6, Li 3 YBr 6, Li, Li 2 CdC 14, Li 2 MgC 14, Li2Cd14, Li2Zn14and Li3OCl. Examples of hydride-based solid electrolyte include LiBH 4, LiBH 4- LiX (X=chlore (Cl), bromine (Br), or iodine (I)), LiNH 2, Li 2 NH, LiBH 4- LiN H 2, Li 3 AlH 6 and combinations thereof.In some examples, the cathode active material is selected from a group consisting of rock salt layered oxides, spinel, polyanion cathodes, olivine cathodes, other lithium transition metal oxides, surface coated and / or doped cathode materials, and low voltage cathode materials.In some examples, the anode active material is selected from a group consisting of carbonaceous material (e.g., graphite, hard carbon, soft carbon, etc.), silicon, silicon mixed with graphite, Li 4 Ti 5 O 12, transition metals (e.g., tin (Sn)), metal oxide / sulfide (e.g., titanium oxide (TiO 2), iron sulfide (FeS), etc.), and other lithium-receiving anode materials.Examples of layered oxides of rock salt (LiCoO 2, LiNiLiNi x Mn y Co 1-x-y O 2, LiNi x Mn y Al 1-x-y O 2, LiNi x Mn1-xO2, Li1+xMO2). Examples of spinel include LiMn 2 O 4, LiNi 0,5 Mn 1,5 O 4. Examples of polyanion cathodes include LiV 2( PO 4)3). Examples of olivine include LiFePO 4 and LiMn x Fe 1-x PO 4.Examples of surface-coated and / or doped cathode materials are mentioned above and further include LiMnO 3- coated LiMn 2 O 4, Li 2 ZrO 3- or Li 3 PO 4- coated LiNi x Mn y Co 1-x-y O_NERmn_and Al-doped LiMn_NERmn_O_NERmn_Beispiele_Beispiele examples of low-voltage cathode material include lithium-containing metal oxide / sulfide (e.g. LiTiS_NERmn_), lithium sulfide and sulfur.In some examples, the conductive additive is selected from a group formed of carbon black, graphite, graphene, graphene oxide, Super P, acetylene black, carbon nanofibers, carbon nanotubes, and other electronically conductive additives.In some examples, the binder is selected from a group consisting of polytetrafluoroethylene (PTFE), sodium carboxymethyl cellulose (CMC), styrene-butadiene rubber (SBR), poly(vinylidene fluoride) (PVDF), nitrile-butadiene rubber (NBR), styrene-ethylene-butylene-styrene copolymer (SEBS), and styrene-butadiene-styrene copolymer (SBS).The foregoing description is for illustrative purposes only and is in no way intended to limit the disclosure, its application, or uses.The broad teachings of the disclosure may be practiced in a variety of forms. While this disclosure includes particular examples, the true scope of the disclosure should not be so limited as other modifications will become apparent upon studying the drawings, specification, and the following claims. It should be appreciated that one or more steps within a method may be performed in different orders (or concurrently) without changing the principles of the present disclosure. Further, although each of the embodiments described above has particular features, one or more of these features described with respect to any embodiment of the disclosure may be implemented in any other embodiment and / or combined with features of any other embodiment, even if this combination is not expressly described. In other words, the described embodiments are not mutually exclusive, and combinations of one or more embodiments with each other remain within the scope of this disclosure.Spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.) are described with various terms including "connected," "engaged," "coupled," "adjacent," "next to," "over," "above," "below," and "arranged.". When a relationship between first and second elements is not expressly described as "direct" in the above disclosure, this relationship may be a direct relationship in which no other intervening elements are present between the first and second elements, but may also be an indirect relationship in which one or more intervening elements (either spatially or functionally) is / are present between the first and second elements. As used herein, the phrase "A, B, and / or C" should be construed using a non-exclusive logical OR operation as a logical (A ORed with B ORed with C) rather than as "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 arrow head, generally indicates the flow of information (e.g., data or instructions) of interest for the mapping. For example, if element A and element B exchange a variety of information, but the information conveyed from element A to element B is relevant for presentation, the arrow may point from element A to element B. This unidirectional arrow does not mean that no other information is transmitted from element B to element A. In the case of information sent from element A to element B, element B may further send requests for the information to element A or confirm the receipt thereof.

Claims

A solid state battery cell comprising: A anode electrodes having an anode active material layer disposed on an anode current collector; C cathode electrodes having a cathode active material layer disposed on a cathode current collector, the cathode active material layer comprising: cathode active material having particles comprising an outer layer of a material selected from a group consisting of LiMnO 3, Li 2 ZrO 3, Li 3 PO 4 and combinations thereof; and a solid state electrolyte having a D 50- size in the range of 4 μm to 12 μm; and S separators disposed between the A anode electrodes and the C cathode electrodes, wherein A, C and S are integers greater than one.The all solid state battery cell of claim 1, wherein the particles comprise lithium nickel cobalt manganese (NMC) particles and the outer layer comprises LiMnO 3.The all solid state battery cell of claim 2, wherein the NMC particles have a diameter of 2 μm < D 50< 5 μm.The all solid state battery cell of claim 2, wherein nickel comprises 50 to 72 mol% of the NMC particles, manganese comprises 8 to 40 mol% of the NMC particles, and cobalt comprises 10 to 20 mol% of the NMC particles.The all solid state battery cell of claim 1, wherein the outer layer has a thickness in the range of 7 nm to 13 nm.The all-solid-state battery cell according to claim 1, wherein the solid electrolyte in the cathode active material layer has a diameter D 90< 15 μm.The solid-state battery cell according to claim 1, wherein the solid electrolyte comprises a sulfidic solid electrolyte selected from a group consisting of pseudobinary sulfide, pseudoternar sulfide, and pseudoquaternary sulfide.The solid-state battery cell according to claim 1, wherein the solid electrolyte is selected from a group consisting of halide-based solid electrolytes and hydride-based solid electrolytes.The all solid state battery cell of claim 1, wherein the cathode active material is selected from a group consisting of rock salt layered oxides, spinel, polyanion cathodes, olivine cathodes, other lithium transition metal oxides, surface coated and / or doped cathode materials, and combinations thereof.The all solid state battery cell of claim 1, wherein the cathode active material layer further comprises a conductive additive selected from a group formed of carbon black, graphite, graphene, graphene oxide, Super P, acetylene black, carbon nanofibers, carbon nanotubes, and combinations thereof.

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