Spontaneous solid-phase prelithiation of silicon anode electrodes for lithium-ion batteries

Abstract

The invention relates to spontaneous solid-phase prelithiation of silicon anode electrodes for lithium-ion battery. A battery cell includes C cathode electrodes comprising a cathode active material layer disposed on one or both sides of a cathode current collector, A anode electrodes, and S separators disposed between adjacent ones of the C cathode electrodes and the A anode electrodes, wherein C, S, and A are integers greater than 1. Each of the A anode electrodes includes an anode current collector, a lithium silicide layer disposed on the anode current collector, and an artificial solid electrolyte interface disposed in a first region on one side of the lithium silicide layer but not in a second region on the one side of the lithium silicide layer. The artificial solid electrolyte interface includes one or more materials selected from lithium carbonate (Li2CO3), lithium nitride (Li3N), lithium oxide (Li2O), lithium phosphide (Li3P), lithium phosphate (Li3PO4), and combinations thereof.

Description

Technical Field

[0001] This disclosure relates to battery packs, and more specifically to pre-lithiated silicon anode electrodes for lithium-ion battery packs. Background Technology

[0002] The information provided in this section is intended to generally present the background of this disclosure. The work of the currently named inventors, to the extent described in this section, and in aspects of the specification that would not otherwise be considered prior art at the time of filing, neither expressly nor implicitly acknowledges that it is prior art to this disclosure.

[0003] Electric vehicles (EVs), such as battery electric vehicles (BEVs), hybrid electric vehicles, and / or fuel cell vehicles, include one or more motors and battery pack systems, which include one or more battery cells, modules, and / or packs. A power control system is used to control the charging and / or discharging of the battery pack system during charging and / or driving.

[0004] The battery pack includes a cathode electrode, an anode electrode, and a separator. The cathode electrode includes a layer of cathode active material disposed on a cathode current collector. The anode electrode includes a layer of anode active material disposed on an anode current collector. Summary of the Invention

[0005] A battery pack includes C cathode electrodes, A anode electrodes, and S separators. The C cathode electrodes include cathode active material layers disposed on one or both sides of a cathode current collector. The S separators are disposed between adjacent cathode and anode electrodes of the C cathode electrodes and the A anode electrodes, wherein C, S, and A are integers greater than 1. Each of the A anode electrodes includes an anode current collector, a lithium silicide layer disposed on the anode current collector, and an artificial solid electrolyte interface disposed in a first region on one side of the lithium silicide layer but in a second region not disposed on said side of the lithium silicide layer.

[0006] Among other features, the artificial solid electrolyte interface includes one or more materials selected from lithium carbonate (Li2CO3), lithium nitride (Li3N), lithium oxide (Li2O), lithium phosphide (Li3P), lithium phosphate (Li3PO4), and combinations thereof.

[0007] Among other features, the first region occupies 50% to 95% of one side of the lithium silicide layer. Artificial solid electrolyte interfaces include lithium carbonate (Li₂CO₃), lithium nitride (Li₃N), lithium oxide (Li₂O), lithium phosphide (Li₃P), and lithium phosphate (Li₃PO₄). The lithium silicide layer includes Li…x Si, where x is from 0.01 to 3.0.

[0008] Among other features, the cathode active material layer includes cathode active materials selected from layered oxides represented by LiMeO2, olivine-type oxides represented by LiMePO4, monoclinic oxides represented by Li3Me2(PO4)3, spinel-type oxides represented by LiMe2O4, tavorite represented by at least one of LiMeSO4F or LiMePO4F, sulfur, lithium sulfide, and combinations thereof, wherein Me is a transition metal. The cathode active material includes a coating layer comprising LiNbO3 and / or Li3PO4.

[0009] Among other features, the cathode active material layer further includes a solid electrolyte selected from pseudo-binary sulfides, pseudo-ternary sulfides, pseudo-quaternary sulfides, oxide-based solid electrolytes, metal-doped or heterovalent oxides, nitride-based solid electrolytes, halide-based solid electrolytes, hydride-based solid electrolytes, borate-based solid electrolytes, and combinations thereof. The cathode active material layer further includes an adhesive selected from polytetrafluoroethylene (PTFE), sodium carboxymethyl cellulose (CMC), styrene-butadiene rubber (SBR), polyvinylidene fluoride (PVDF), nitrile rubber (NBR), styrene-ethylene-butene-styrene copolymer (SEBS), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), polyethylene oxide (PEO), polyacrylonitrile (PAN), polyacrylic acid (PAA), and styrene-butadiene-styrene copolymer (SBS).

[0010] Among other features, the battery pack cells are solid-state. The S separators include solid electrolytes selected from pseudo-binary sulfides, pseudo-ternary sulfides, pseudo-quaternary sulfides, oxide-based solid electrolytes, metal-doped or heterovalent oxides, nitride-based solid electrolytes, halide-based solid electrolytes, hydride-based solid electrolytes, borate-based solid electrolytes, and combinations thereof.

[0011] Among other features, the liquid electrolyte includes a lithium salt dissolved in at least one organic solvent. The S separators comprise a layer made of a material selected from polyolefins, cellulose, polyvinylidene fluoride (PVDF), porous polyimide, and ceramic coatings.

[0012] A method for manufacturing an anode electrode for a battery pack includes disposing a silicon layer on one side of an anode current collector and depositing a multifunctional solid electrolyte layer in a first region on the opposite side of the silicon layer. A second region on the opposite side of the silicon layer is not covered by the multifunctional solid electrolyte layer. The method includes depositing a lithium metal layer on the multifunctional solid electrolyte layer in the first region and on the silicon layer in the second region.

[0013] Among other features, the multifunctional solid electrolyte layer is deposited with a thickness of 5 nm to 200 nm. The multifunctional solid electrolyte layer is deposited with a thickness of 20 nm to 60 nm. The first region occupies 50% to 95% of one side of the silicon layer. The multifunctional solid electrolyte layer is selected from carbon-incorporated lithium phosphorusoxynitride, lithium phosphorusoxynitride, lithium phosphate, and combinations thereof.

[0014] Among other features, after the pre-lithiation period, the multifunctional solid electrolyte layer decomposes to form an artificial solid electrolyte interface, which includes lithium carbonate (Li2CO3), lithium nitride (Li3N), lithium oxide (Li2O), lithium phosphide (Li3P), and lithium phosphate (Li3PO4).

[0015] Among other features, the multifunctional solid electrolyte layer is selected from lithium phosphooxynitrides incorporated with carbon. The multifunctional solid electrolyte layer decomposes to form an artificial solid electrolyte interface, which includes lithium carbonate (Li2CO3), lithium nitride (Li3N), lithium oxide (Li2O), lithium phosphide (Li3P), and lithium phosphate (Li3PO4).

[0016] Among other features, magnetron sputtering is used to deposit a multifunctional solid electrolyte layer. Vacuum thermal deposition is used to deposit the lithium metal layer.

[0017] Among other features, after the pre-lithiation period, the silicon layer includes Li x Si, where x is from 0.01 to 3.0. After the pre-lithiation period, the silicon layer includes Li. x Si, where x is between 0.8 and 1.2.

[0018] The present invention discloses the following solutions:

[0019] Option 1. A battery pack comprising:

[0020] C cathode electrodes, each comprising a cathode active material layer disposed on one or both sides of the cathode current collector;

[0021] A anode electrode; and

[0022] S isolation elements are arranged between adjacent cathode and anode electrodes of the C cathode electrodes and the A anode electrodes, where C, S, and A are integers greater than 1.

[0023] Each of the A anode electrodes comprises:

[0024] Anode current collector;

[0025] A lithium silicide layer is disposed on the anode current collector; and

[0026] An artificial solid electrolyte interface is disposed in a first region on one side of the lithium silicide layer but not in a second region on the same side of the lithium silicide layer.

[0027] Option 2. The battery pack according to Option 1, wherein the artificial solid electrolyte interface comprises one or more materials selected from lithium carbonate (Li2CO3), lithium nitride (Li3N), lithium oxide (Li2O), lithium phosphide (Li3P), lithium phosphate (Li3PO4), and combinations thereof.

[0028] Option 3. The battery pack according to Option 2, wherein the first region occupies 50% to 95% of one side of the lithium silicide layer.

[0029] Option 4. The battery pack according to Option 1, wherein the artificial solid electrolyte interface includes lithium carbonate (Li2CO3), lithium nitride (Li3N), lithium oxide (Li2O), lithium phosphide (Li3P), and lithium phosphate (Li3PO4).

[0030] Option 5. The battery pack according to Option 1, wherein the lithium silicide layer comprises Li x Si, where x is from 0.01 to 3.0.

[0031] Option 6. The battery pack according to Option 1, wherein the cathode active material layer comprises a cathode active material selected from layered oxides represented by LiMeO2, olivine-type oxides represented by LiMePO4, monoclinic oxides represented by Li3Me2(PO4)3, spinel-type oxides represented by LiMe2O4, lithium hydroxyphosphide, sulfur, lithium sulfide, and combinations thereof represented by at least one of LiMeSO4F or LiMePO4F, wherein Me is a transition metal.

[0032] Option 7. The battery pack according to Option 6, wherein the cathode active material comprises a coating containing LiNbO3 and / or Li3PO4.

[0033] Option 8. The battery pack according to Option 6, wherein:

[0034] The cathode active material layer further includes a solid electrolyte selected from pseudo-binary sulfides, pseudo-ternary sulfides, pseudo-quaternary sulfides, oxide-based solid electrolytes, metal-doped or heterovalent oxides, nitride-based solid electrolytes, halide-based solid electrolytes, hydride-based solid electrolytes, borate-based solid electrolytes, and combinations thereof.

[0035] The cathode active material layer further includes an adhesive selected from polytetrafluoroethylene (PTFE), sodium carboxymethyl cellulose (CMC), styrene-butadiene rubber (SBR), polyvinylidene fluoride (PVDF), nitrile rubber (NBR), styrene-ethylene-butene-styrene copolymer (SEBS), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), polyethylene oxide (PEO), polyacrylonitrile (PAN), polyacrylic acid (PAA), and styrene-butadiene-styrene copolymer (SBS).

[0036] Option 9. The battery pack according to Option 1, wherein:

[0037] The battery pack cells are solid-state, and

[0038] The S isolators include solid electrolytes selected from pseudo-binary sulfides, pseudo-ternary sulfides, pseudo-quaternary sulfides, oxide-based solid electrolytes, metal-doped or heterovalent oxides, nitride-based solid electrolytes, halide-based solid electrolytes, hydride-based solid electrolytes, borate-based solid electrolytes, and combinations thereof.

[0039] Option 10. The battery pack according to Option 1, further comprising:

[0040] A liquid electrolyte comprising a lithium salt dissolved in at least one organic solvent.

[0041] The S separators comprise layers made of materials selected from polyolefins, cellulose, polyvinylidene fluoride (PVDF), porous polyimide, and ceramic coatings.

[0042] Option 11. A method for manufacturing an anode electrode for a battery pack, comprising:

[0043] A silicon layer is arranged on one side of the anode current collector;

[0044] A multifunctional solid electrolyte layer is deposited in a first region on the opposite side of the silicon layer.

[0045] The second region on the opposite side of the silicon layer is not covered by the multifunctional solid electrolyte layer; and

[0046] Lithium metal layers are deposited on the multifunctional solid electrolyte layer in the first region and on the silicon layer in the second region.

[0047] Option 12. The method according to Option 11, wherein the multifunctional solid electrolyte layer is deposited with a thickness of 5 nm to 200 nm.

[0048] Option 13. The method according to Option 11, wherein the multifunctional solid electrolyte layer is deposited with a thickness of 20 nm to 60 nm.

[0049] Option 14. The method according to Option 11, wherein the first region occupies 50% to 95% of one side of the silicon layer.

[0050] Option 15. The method according to Option 11, wherein the multifunctional solid electrolyte layer is selected from lithium phosphorus oxynitrides incorporated with carbon, lithium phosphorus oxynitrides, lithium phosphate, and combinations thereof.

[0051] Option 16. The method according to Option 15, wherein after the pre-lithiation period, the multifunctional solid electrolyte layer is decomposed to form an artificial solid electrolyte interface comprising lithium carbonate (Li2CO3), lithium nitride (Li3N), lithium oxide (Li2O), lithium phosphide (Li3P) and / or lithium phosphate (Li3PO4).

[0052] Option 17. The method according to Option 11, wherein:

[0053] The multifunctional solid electrolyte layer is selected from carbon-incorporated lithium phosphorus oxynitrides, and

[0054] The multifunctional solid electrolyte layer is decomposed to form an artificial solid electrolyte interface comprising lithium carbonate (Li2CO3), lithium nitride (Li3N), lithium oxide (Li2O), lithium phosphide (Li3P), and lithium phosphate (Li3PO4).

[0055] Option 18. The method according to Option 11, wherein:

[0056] The multifunctional solid electrolyte layer was deposited using magnetron sputtering, and

[0057] The lithium metal layer was deposited using vacuum thermal deposition.

[0058] Option 19. The method according to Option 11, wherein after the pre-lithiation period, the silicon layer comprises Li x Si, where x is from 0.01 to 3.0.

[0059] Option 20. The method according to Option 11, wherein after the pre-lithiation period, the silicon layer comprises Li x Si, where x is between 0.8 and 1.2.

[0060] Further applicability of this disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are intended to be illustrative only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0061] This disclosure will be more fully understood from the detailed embodiments and the accompanying drawings, in which:

[0062] Figure 1 This is a side cross-sectional view of an example of a battery pack according to the present disclosure, comprising C cathode electrodes, A anode electrodes, and S separators;

[0063] Figures 2A to 2D This is a side cross-sectional view showing the manufacture of one of the A anode electrodes according to the present disclosure;

[0064] Figure 3 This is a side cross-sectional view of an example of a liquid-based battery pack including one of A anode electrodes according to the present disclosure;

[0065] Figure 4 This is a side cross-sectional view of an example of a solid-state battery pack including one of A anode electrodes according to the present disclosure;

[0066] Figure 5A and 5B These are diagrams illustrating examples of the initial formation and cycling of a liquid-based battery pack according to this disclosure; and

[0067] Figure 6A and 6B This is a diagram illustrating an example of the initial formation and cycling of a solid-state battery pack according to this disclosure.

[0068] In the accompanying drawings, reference numerals may be used repeatedly to identify similar and / or identical elements. Detailed Implementation

[0069] Although the battery pack according to this disclosure is described in the context of a vehicle, the battery pack can be used in other types of mobile and / or stationary applications.

[0070] Silicon (Si) has emerged as a promising alternative to graphite-based anode electrodes because it is environmentally friendly and has a reasonable electrochemical potential (~0.3V vs. Li / Li). + ) and high theoretical capacity (for Li 4.4 (Si has a capacity of 4200 mAh / g). However, the Si anode electrode undergoes significant volume expansion during charging.

[0071] Large volumetric changes in silicon lead to cracking, reformation of the solid electrolyte interface (SEI), and / or electrode fragmentation. Battery packs including Si anode electrodes also exhibit loss of active lithium due to the continuous formation and irreversible reactions of the SEI. Consequently, battery packs including Si anode electrodes have reduced capacity and / or shorter cycle life.

[0072] This disclosure relates to a pre-lithiated silicon anode electrode fabricated using a spontaneous solid-state reaction. A first region 57 of the silicon layer of the anode electrode is coated with a thin, multifunctional solid electrolyte layer (e.g., 5 nm to 200 nm), while a second region 59 of the silicon layer is uncovered. A lithium metal layer is deposited on the first region 57 and the second region 59 of the multifunctional solid electrolyte layer (e.g., directly on the silicon layer).

[0073] A spontaneous solid-state reaction occurs between the lithium metal layer and the silicon layer. This reaction enables pre-lithiation of the silicon anode. A robust artificial solid electrolyte interface (SEI) is created due to the decomposition of the multifunctional solid electrolyte layer. As a result, the anode electrode exhibits improved lithium capacity, enhanced initial coulombic efficiency, and improved battery cycle life.

[0074] Now for reference Figure 1 The battery pack 10 includes C cathode electrodes 20, A anode electrodes 40, and S separators 32 arranged in a predetermined order within the battery pack stack 12, where C, S, and A are integers greater than zero. In some instances, the vehicle 11 includes a battery pack module or pack 13 that includes the battery pack 10. The battery pack stack 12 is arranged within a housing 50. In some instances, the battery pack 10 is liquid-based, and a liquid electrolyte is added to the housing 50. In other instances, the battery pack is solid-state, and a solid electrolyte is used.

[0075] The C cathode electrodes 20-1, 20-2, ..., 20-C include a cathode active material layer 24 disposed on one or both sides of the cathode current collector 26. The A anode electrodes 40-1, 40-2, ..., 40-A include an anode active material layer 42 disposed on one or both sides of the anode current collector 46.

[0076] During charging / discharging, A anode electrodes 40 exchange lithium ions with C cathode electrodes 20. In some instances, the cathode active material layer 24 includes a coating comprising one or more active materials, a solid electrolyte (for solid-state battery packs), one or more conductive additives, and / or one or more binder materials, which are applied to the current collector.

[0077] In some instances, the anode current collector 46 and / or the cathode current collector 26 comprises metal foil, metal mesh, perforated metal, 3D metal foam, and / or expanded metal. External tabs 28 and 48 are connected to the current collectors of the cathode and anode electrodes, respectively, and may be arranged on the same or different sides of the battery pack stack 12. External tabs 28 and 48 are connected to the terminals of the battery cells in the battery pack.

[0078] Now for reference Figures 2A to 2D This illustrates a method for manufacturing one of A anode electrodes. Figure 2A In this process, a silicon layer 52 is formed on one or both sides of the anode current collector 46. Figure 2B In this structure, the first region 57 of the silicon layer 52 is coated with a thin multifunctional solid electrolyte layer 54, while the second region 59 of the silicon layer 52 is not. In other words, not all of the silicon layer 52 is covered by the multifunctional solid electrolyte layer 54.

[0079] In some instances, the multifunctional solid electrolyte layer 54 is selected from carbon-incorporated lithium phosphorus oxynitride (LiCPON (Li 3.32 C 0.27 PO 3.65 N 0.70 ), lithium phosphorus oxynitride (LiPON(Li 3.3 PO 3.9 N 0.17 Lithium phosphate (Li3PO4) and combinations thereof. In some instances, a multifunctional solid electrolyte layer 54 is deposited on the silicon layer 52 using magnetron sputtering, although other methods may be used. In some instances, the multifunctional solid electrolyte layer 54 is deposited in a first region 57 with a thickness of 5 nm to 200 nm. In some instances, the multifunctional solid electrolyte layer 54 is deposited in the first region 57 with a thickness of 20 nm to 60 nm. In some instances, the first region 57 of the silicon layer 52 covers 50% to 95% of the top surface of the silicon layer 52. The second region 59 covers 5% to 50% of the top surface of the silicon layer 52.

[0080] exist Figure 2C In this process, a lithium metal layer 56 is deposited on a multifunctional solid electrolyte layer 54 and a silicon layer 52. In other words, a portion of the lithium metal layer 56 is in contact with the multifunctional solid electrolyte layer 54, while a portion of the lithium metal layer 56 is in contact with the silicon layer 52. In some instances, vacuum thermal deposition is used to deposit the lithium metal layer 56, although other methods can be used. After a predetermined period, a spontaneous solid-phase reaction occurs between the lithium metal layer 56 and the silicon layer 52. In some instances, the predetermined period is 1 to 5 days.

[0081] A spontaneous solid-state reaction enables the pre-lithiation of the silicon layer 52, while simultaneously creating a robust artificial solid electrolyte interface (SEI) due to the decomposition of the multifunctional solid electrolyte layer 54. In some instances, LiCPON decomposes into one or more of lithium carbonate (Li₂CO₃), lithium nitride (Li₃N), lithium oxide (Li₂O), lithium phosphide (Li₃P), and / or lithium phosphate (Li₃PO₄). When lithium phosphorus oxynitride (LiPON(Li 3.3 PO 3.9 N 0.17 When lithium phosphate (Li3PO4) decomposes, the artificial SEI includes lithium nitride (Li3N), lithium oxide (Li2O), and lithium phosphide (Li3P). When lithium phosphate (Li3PO4) decomposes, the artificial SEI includes Li2O and Li3P.

[0082] During the solid-state reaction, lithium ions (Li) are stripped from the lithium metal layer 54. + The electrolyte is transferred to the silicon layer 52 through the first region 57 of the multifunctional solid electrolyte layer 54. For example, the ionic conductivity of LiCPON is 3.06 × 10⁻⁶. -6 S / cm. Electrons required for a spontaneous reaction (e - Conduction occurs through direct contact between the lithium metal layer 56 and the silicon layer 52 in the second region 59 of the silicon layer 52 (the region not covered by the multifunctional solid electrolyte layer 54). Lithium ions (Li) + and electronic e - This enables a spontaneous solid-state reaction to occur between the lithium metal layer 56 and the silicon layer 52, and then effectively pre-lithiates the silicon layer 52 according to the following reaction:

[0083]

[0084] Spontaneously formed Li x Si compensates for irreversible lithium loss caused by SEI formation and improves lithium capacity. When the multifunctional solid electrolyte layer 54 is LiCPON, it decomposes into Li2CO3, Li3N, Li2O, Li3P, and Li3PO4 upon contact with the lithium metal layer 56. Li3N, Li3P, and Li3PO4 have high ionic conductivity, and Li3P has high electronic conductivity. These materials enable the SEI to have good ion and electron transport properties. The artificial SEI effectively isolates the contact between the silicon layer 52 in the first region 57 and the electrolyte, suppresses electrolyte decomposition of the separator, and reduces irreversible lithium loss.

[0085] In some instances, the anodic active material layer comprises 30% to 100% by weight of silicon active material, 0% to 20% by weight of solid electrolyte, 0% to 10% by weight of conductive additives, and 0% to 10% by weight of binder.

[0086] In some instances, a multifunctional solid electrolyte layer 54 is deposited on a silicon layer 52 using magnetron sputtering. In some instances, the multifunctional solid electrolyte layer 54 is deposited in a first region 57 with a thickness of 5 nm to 200 nm. In some instances, the multifunctional solid electrolyte layer 54 is deposited in the first region 57 with a thickness of 20 nm to 60 nm. In some instances, the multifunctional solid electrolyte layer 54 covers 50% to 95% of the silicon layer 52. In some instances, the multifunctional solid electrolyte layer 54 includes a carbon-incorporated lithium phosphorus oxynitride (LiPON). 3.32 C 0.27 PO 3.65 N 0.70 (LiCPON), lithium phosphooxynitride (Li 3.3 PO 3.9 N 0.17 (LiPON), lithium phosphate (Li3PO4) and combinations thereof.

[0087] In some instances, a lithium metal layer 56 is deposited on a multifunctional solid electrolyte layer 54 and a silicon layer 52 using vacuum thermal deposition. In some instances, the lithium metal layer 56 has a target thickness of 1 to 20 μm. In some instances, the lithium metal layer 56 has a target thickness of 2 to 6 μm.

[0088] In some instances, following spontaneous solid-state pre-lithiation, the artificial SEI of the formed anode electrode comprises 8 to 16 wt% Li₂CO₃, 12 to 18 wt% Li₃N, 20 to 30 wt% Li₂O, 18 to 26 wt% Li₃P, and 18 to 26 wt% Li₃PO₄. In some instances, following spontaneous solid-state pre-lithiation, Li₂O... x The "x" value for the Si anode electrode ranges from 0.01 to 3.0. Following spontaneous solid-state pre-lithiation, Li... x The "x" value for the Si anode electrode is 0.8 to 1.2.

[0089] Now for reference Figure 3 The aforementioned pre-lithiated silicon anode electrode can be used in lithium-ion battery packs based on liquid electrolytes to improve the delivered lithium capacity and / or battery cycle capability. In this example, the C cathode electrodes include a cathode active material 62 (e.g., LCO) and a liquid electrolyte 64 (e.g., 1.2M LiPF6 in carbonate (ester)). The separator 32 includes a polymer separator, such as polypropylene (PP) / polyethylene (PE). The anode electrode is as described above.

[0090] More generally, liquid electrolytes comprise lithium salts dissolved in organic solvents or mixtures of organic solvents. In some instances, the lithium salt is selected from lithium hexafluorophosphate, lithium perchlorate, lithium tetrafluoroborate, lithium bis(trifluoromethane)sulfonylimide, and combinations thereof. In some instances, the solvent is selected from carbonates (esters), esters, lactones, chain ethers, cyclic ethers, and combinations thereof.

[0091] Now for reference Figure 4 The aforementioned pre-lithiated silicon anode electrode can be used in solid-state battery packs to improve the delivered lithium capacity and / or battery cycle capability. In this example, the C cathode electrodes include a cathode active material 72 (e.g., NMC721) and a solid electrolyte 74 (e.g., Li6PS5Cl). The separator 32 includes a solid electrolyte (e.g., Li6PS5Cl). The anode electrode is as described above.

[0092] In some instances, the cathode active material layer comprises 30% to 98% by weight of cathode active material, 0% to 30% by weight of solid electrolyte, 0% to 20% by weight of carbon additives, and 0% to 20% by weight of binder.

[0093] In some instances, the cathode active material is selected from layered oxides represented by the formula LiMeO2, olivine-type oxides represented by the formula LiMePO4, monoclinic oxides represented by the formula Li3Me2(PO4)3, spinel-type oxides represented by the formula LiMe2O4, lithium hydroxyphosphorus iron oxides represented by one or both of the following formulas LiMeSO4F or LiMePO4F, or combinations thereof, wherein Me is a transition metal (e.g., Co, Ni, Mn, Fe, Al, V, or combinations thereof). In some instances, the cathode active material comprises sulfur or lithium sulfide (Li2S). In some instances, the cathode active material is coated with a coating comprising lithium niobate (LiNbO3) and / or lithium phosphate (Li3PO4).

[0094] In some instances, conductive additives include carbon black, graphite, graphene, graphene oxide, Super P, acetylene black, carbon nanofibers, carbon nanotubes, and other electronically conductive additives.

[0095] In some instances, the adhesive includes one or more materials selected from polytetrafluoroethylene (PTFE), sodium carboxymethyl cellulose (CMC), styrene-butadiene rubber (SBR), polyvinylidene fluoride (PVDF), nitrile rubber (NBR), styrene-ethylene-butene-styrene copolymer (SEBS), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), polyethylene oxide (PEO), polyacrylonitrile (PAN), polyacrylic acid (PAA), styrene-butadiene-styrene copolymer (SBS), etc.

[0096] In some instances, the solid electrolyte is selected from pseudo-binary sulfides, pseudo-ternary sulfides, pseudo-quaternary sulfides, oxide-based solid electrolytes, metal-doped or heterovalent oxides, nitride-based solid electrolytes, halide-based solid electrolytes, hydride-based solid electrolytes, borate-based solid electrolytes, and combinations thereof.

[0097] Examples of pseudo-binary sulfides include the Li2S-P2S5 system (Li3PS4, Li7P3S) 11 and Li 9.6 P3S 12 The following systems are also mentioned: Li2S-SnS2 (Li4SnS4), Li2S-SiS2, Li2S-GeS2, Li2S-B2S3, Li2S-Ga2S3, Li2S-P2S3, and Li2S-Al2S3.

[0098] Examples of pseudo-ternary sulfides include the Li₂O-Li₂S-P₂S₅ system, the Li₂S-P₂S₅-P₂O₅ system, the Li₂S-P₂S₅-GeS₂ system, and (Li 3.25 Ge 0.25 P 0.75 S4 and Li 10 GeP2S 12 The Li₂S-P₂S₅-LiX system (where X = F, Cl, Br, I), (Li₆PS₅Br, Li₆PS₅Cl, L₇P₂S₈I and Li₄PS₄I), the Li₂S-As₂S₅-SnS₂ system, (Li 3.833 Sn 0.833 As 0.166 The following systems were mentioned: Li₂S-P₂S₅-Al₂S₃, Li₂S-Liₓ-SiS₂ (where X = F, Cl, Br, I), 0.4LiI-0.6Li₄SnS₄, and Li₂S₃. 11 Si2PS 12 Examples of pseudo-quaternary sulfides include the Li₂O-Li₂S-P₂S₅-P₂O₅ system, Li… 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 Li7P 2.9 Mn 0.1 S 10.7 I 0.3 and Li 10.35 [Sn 0.27 Si 1.08 ]P 1.65 S 12 .

[0099] Examples of halide-based sulfide electrolytes include Li3YCl6, Li3InCl6, Li3YBr6, LiI, and Li2CdC. 14 Li2MgC 14 Li2Cd 14 Li2Zn 14 And Li3OCl. Examples of hydride-based sulfide electrolytes include LiBH4, LiBH4-LiX (X = Cl, Br, or I), LiNH2, Li2NH, LiBH4-LiNH2, and Li3AlH6.

[0100] Examples of oxide-based solid electrolytes include garnet-type electrolytes (e.g., Li7La3Zr2O). 12 ), perovskite type (e.g., Li), 3x La 2 / 3-x TiO3), NASICON type (e.g., Li) 1.4 Al 0.4 Ti 1.6 (PO4)3 and Li 1+x Al x Ge 2-x (PO4)3), LISICON type (e.g., Li 2+2x Zn 1-x GeO4).

[0101] Examples of metal-doped or anisovalently substituted oxide solid electrolytes include Al, Nb, or Sb-doped Li7La3Zr2O 12 Ga-substituted Li7La3Zr2O 12 LiSn2P3O substituted with Cr and V 12 Al-substituted perovskites, Li 1+x+ y Al x Ti 2-x Si y P 3-y O 12。 Examples of nitride-based solid electrolytes include Li3N, Li7PN4, and LiSi2N3. Examples of borate-based solid electrolytes include Li2B4O7 and Li2O-B2O3-P2O5.

[0102] In some instances, the separator comprises a solid electrolyte membrane comprising 20% ​​to 100% by weight of a solid electrolyte, 0% to 30% by weight of a filler, and 0% to 20% by weight of a binder. In some instances, the solid electrolyte is selected from the examples listed above.

[0103] In some examples, the filler comprises at least one material selected from oxide particles, polymer backbones, lithium salts, and combinations thereof. In some examples, the oxide particles are selected from silicon oxide (SiO2), aluminum oxide (Al2O3), titanium oxide (TiO2), and zirconium oxide (ZrO2). In some examples, the polymer backbone comprises polypropylene (PP) or polyethylene (PE).

[0104] In some examples, the binders for solid electrolyte membranes include polyvinylidene fluoride (PVDF), poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP), polytetrafluoroethylene (PTFE), sodium carboxymethyl cellulose (CMC), styrene-butadiene rubber (SBR), nitrile rubber (NBR), styrene-ethylene-butene-styrene copolymer (SEBS), polyethylene oxide (PEO), polyvinylpyrrolidone (PVP), polyvinyl alcohol, and polyacrylic acid (PAA). In some examples, the solid electrolyte membrane has a thickness ranging from 5 μm to 200 μm.

[0105] In some instances, the separator layer in Figure 2 has a porosity of 5% to 100% (e.g., 90%). The liquid electrolyte wets the pores of the separator layer. In some instances, the separator layer is made of a material selected from polyolefins, cellulose, polyvinylidene fluoride (PVDF), porous polyimide, ceramic coatings, and high-temperature stable materials.

[0106] In some instances, polyolefin-based spacers are selected from polyacetylene: polypropylene (PP), polyethylene (PE), two-layer type: PP-PE, and three-layer type (PP-PE-PP). In some instances, ceramic-coated spacers include a PE layer coated with silicon dioxide (SiO2).

[0107] In some examples, high-temperature stable materials are selected from nonwovens based on polyimide (PI) nanofibers, nano-sized Al2O3 and poly(lithium 4-styrene sulfonate) coated polyethylene films, SiO2 coated polyethylene (PE) spacers, cepolyimide-coated polyethylene spacers, polyetherimide (PEI) spacers (bisphenol-acetone phthalic anhydride (BPADA) and p-phenylenediamine), expanded polytetrafluoroethylene reinforced polyvinylidene fluoride-hexafluoropropylene spacers, sandwich-structured PVdF / PMIA / PVdF nanofiber spacers, etc.

[0108] Now for reference Figure 5A and 5B , showed Figure 3The initial formation and cycle performance of liquid-based battery packs are shown. At 210, the initial formation of a first battery pack including an anode electrode with a silicon layer is shown. The first battery pack produces a charge capacity of 192 mAh / g, a discharge capacity of 155 mAh / g, and a coulombic efficiency of 81%. At 212, a second battery pack includes an anode electrode with a silicon layer, a multifunctional solid electrolyte layer (50 nm LiCPON), and a lithium layer (6 μm lithium metal). The second battery pack produces a charge capacity of 192 mAh / g, a discharge capacity of 177 mAh / g, and a coulombic efficiency of 92%. At 214, a third battery pack includes an anode electrode with a silicon layer and a lithium metal layer (e.g., 6 μm lithium). The third battery pack produces a charge capacity of 190 mAh / g, a discharge capacity of 175 mAh / g, and a coulombic efficiency of 92%. As can be seen, the pre-lithiated Si film obtained through spontaneous solid-state reaction significantly improves the delivered lithium capacity, initial coulombic efficiency, and battery cycle performance.

[0109] Now for reference Figure 6A and 6B , showed Figure 4 The initial formation and cycle performance of solid-state battery packs are shown. Initial formation of a first battery pack including an anode electrode with a silicon layer is shown at 220. The first battery pack exhibits a charge capacity of 190 mAh / g, a discharge capacity of 145 mAh / g, and a coulombic efficiency of 76%. A second battery pack including an anode electrode with a silicon layer, a multifunctional solid electrolyte layer (50 nm LiCPON), and a lithium layer (6 μm lithium) is shown at 224. The second battery pack exhibits a charge capacity of 191 mAh / g, a discharge capacity of 153 mAh / g, and a coulombic efficiency of 80%. The pre-lithiated Si film obtained through spontaneous solid-state reaction significantly improves the delivered lithium capacity, initial coulombic efficiency, and battery cycle performance.

[0110] The foregoing description is illustrative in nature and is in no way intended to limit this disclosure, its application, or its use. The broad teachings of this disclosure can be implemented in many forms. Therefore, although this disclosure includes specific examples, its true scope should not be so limited, as other modifications will become apparent upon examination of the drawings, description, and appended claims. It should be understood that one or more steps within the method may be performed in a different order (or simultaneously) without altering the principles of this disclosure. Furthermore, although each embodiment is described above as having certain features, any one or more of those features described with respect to any embodiment of this disclosure may be implemented in any other embodiment and / or combined with features in any other embodiment, even if such combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and permutations and combinations of one or more embodiments with each other exist within the scope of this disclosure.

[0111] Spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including “connection,” “joint,” “coupled,” “adjacent,” “closely adjacent,” “above,” “under,” and “set.” Unless explicitly described as “direct,” the relationship between the first and second elements described in the foregoing disclosure can be a direct relationship, where no other intermediary element exists between the first and second elements, or an indirect relationship, where one or more intermediary elements exist between the first and second elements (spatially or functionally). As used herein, the phrase at least one of A, B, and C should be interpreted as meaning the logic of using non-exclusive OR (A OR B OR C), and should not be interpreted as meaning “at least one A, at least one B, and at least one C.”

Claims

1. A battery pack comprising: C cathode electrodes, each comprising a cathode active material layer disposed on one or both sides of the cathode current collector; A anode electrode; and S isolation elements are arranged between adjacent cathode and anode electrodes of the C cathode electrodes and the A anode electrodes, where C, S, and A are integers greater than 1. Each of the A anode electrodes comprises: Anode current collector; A lithium silicide layer is disposed on the anode current collector; and An artificial solid electrolyte interface is disposed in a first region on one side of the lithium silicide layer but not in a second region on the same side of the lithium silicide layer.

2. The battery pack according to claim 1, wherein the artificial solid electrolyte interface comprises one or more materials selected from lithium carbonate (Li2CO3), lithium nitride (Li3N), lithium oxide (Li2O), lithium phosphide (Li3P), lithium phosphate (Li3PO4), and combinations thereof.

3. The battery pack according to claim 2, wherein the first region occupies 50% to 95% of one side of the lithium silicide layer.

4. The battery pack according to claim 1, wherein the artificial solid electrolyte interface comprises lithium carbonate (Li2CO3), lithium nitride (Li3N), lithium oxide (Li2O), lithium phosphide (Li3P), and lithium phosphate (Li3PO4).

5. The battery pack according to claim 1, wherein the lithium silicide layer comprises Li x Si, where x is from 0.01 to 3.

0.

6. The battery pack according to claim 1, wherein the cathode active material layer comprises a cathode active material selected from layered oxides represented by LiMeO2, olivine-type oxides represented by LiMePO4, monoclinic oxides represented by Li3Me2(PO4)3, spinel-type oxides represented by LiMe2O4, lithium hydroxyphosphide, sulfur, lithium sulfide, and combinations thereof represented by at least one of LiMeSO4F or LiMePO4F, wherein Me is a transition metal.

7. The battery pack according to claim 6, wherein the cathode active material comprises a coating containing LiNbO3 and / or Li3PO4.

8. The battery pack according to claim 6, wherein: The cathode active material layer further includes a solid electrolyte selected from pseudo-binary sulfides, pseudo-ternary sulfides, pseudo-quaternary sulfides, oxide-based solid electrolytes, metal-doped or heterovalent oxides, nitride-based solid electrolytes, halide-based solid electrolytes, hydride-based solid electrolytes, borate-based solid electrolytes, and combinations thereof. The cathode active material layer further includes an adhesive selected from polytetrafluoroethylene (PTFE), sodium carboxymethyl cellulose (CMC), styrene-butadiene rubber (SBR), polyvinylidene fluoride (PVDF), nitrile rubber (NBR), styrene-ethylene-butene-styrene copolymer (SEBS), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), polyethylene oxide (PEO), polyacrylonitrile (PAN), polyacrylic acid (PAA), and styrene-butadiene-styrene copolymer (SBS).

9. The battery pack according to claim 1, wherein: The battery pack cells are solid-state, and The S isolators include solid electrolytes selected from pseudo-binary sulfides, pseudo-ternary sulfides, pseudo-quaternary sulfides, oxide-based solid electrolytes, metal-doped or heterovalent oxides, nitride-based solid electrolytes, halide-based solid electrolytes, hydride-based solid electrolytes, borate-based solid electrolytes, and combinations thereof.

10. The battery pack according to claim 1, further comprising: A liquid electrolyte comprising a lithium salt dissolved in at least one organic solvent. The S separators comprise layers made of materials selected from polyolefins, cellulose, polyvinylidene fluoride (PVDF), porous polyimide, and ceramic coatings.

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