Solid-state battery cell, battery device, electric device and positive electrode

Abstract

The present disclosure provides a solid-state battery cell, a battery device, an electric device and a positive electrode. The solid-state battery cell comprises a positive electrode, an electrolyte layer and a negative electrode, wherein the electrolyte layer is located between the positive electrode and the negative electrode; the positive electrode comprises a positive electrode film layer; the positive electrode film layer comprises a positive electrode active material and a solid-state electrolyte; the positive electrode active material comprises Cu2S and one or more of CuI and a cuprous ion conductor, i.e., Cu6+a+cP1-aAaS5-b+cBbX1-c, where 0≤a<1, 0≤b<1, -1<c<1, A comprises one or more elements selected from Ge, Si, Sn, Al, Zr and Sb, B comprises one or more elements selected from O, Se and Te, and X comprises one or more elements selected from Cl, Br and I; and the solid-state electrolyte comprises one or more of a sulfide electrolyte and a halide electrolyte. The solid-state battery cell has a high energy density, good cycle performance and good rate performance.

Description

Solid - state battery cell, battery device, electrical device, positive electrode

[0001] Cross - reference to related applications

[0002] This application claims the priority of Chinese Patent Application No. 202510129957.4, entitled "Solid - state battery cell, battery device, electrical device, positive electrode", filed on February 5, 2025, the entire content of which is incorporated herein by reference. Technical field

[0003] [[ID=ll]]The present disclosure relates to a solid - state battery cell, a battery device, an electrical device, and a positive electrode. Background art

[0004] Compared with battery cells using liquid electrolytes, solid - state battery cells are less likely to catch fire or explode, and have high reliability and high energy density. Currently, between traditional positive - electrode active materials, such as lithium transition metal oxides, and solid electrolytes, such as sulfide electrolytes, there is a solid - solid contact, which often leads to interface problems, affecting the capacity and performance of solid - state battery cells. Summary of the invention

[0005] The present disclosure provides a solid - state battery cell, a battery device, an electrical device, and a positive electrode, and the solid - state battery cell has both high energy density, good cycle performance, and good rate performance.

[0006] In a first aspect, the present disclosure provides a solid - state battery cell, including a positive electrode, an electrolyte layer, and a negative electrode. The electrolyte layer is located between the positive electrode and the negative electrode. The positive electrode includes a positive - electrode film layer, and the positive - electrode film layer includes a positive - electrode active material and a solid electrolyte. The positive - electrode active material includes Cu2S, and one or more of CuI, cuprous - ion conductor Cu 6+a+c P 1- a A a S 5-b+c B b X 1-c where 0≤a<1, 0≤b<1, - 1<c<1, A includes one or more elements selected from Ge, Si, Sn, Al, Zr, and Sb, B includes one or more elements selected from O, Se, and Te, and X includes one or more elements selected from Cl, Br, and I; the solid electrolyte includes one or more of sulfide electrolytes and halide electrolytes.

[0007] The positive - electrode active material of the present disclosure includes Cu2S, and one or more of CuI, cuprous - ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X1-c One or more of these. CuI can catalyze the conversion reaction between Cu₂S and S (0 valence), enhancing the kinetics of this conversion reaction. Cu(II) is a cuprous ion conductor. 6+a+c P 1-a A a S 5-b+c B b X 1-c It has high ionic conductivity and can accelerate the reaction of Cu sub-cuprous ions in the positive electrode. + The transport of Cu2S ions enhances the transport of Cu2S ions. + The ion transport kinetics of this invention are excellent. Therefore, the cathode of this invention exhibits superior ion transport kinetics, resulting in high discharge capacity even at high current densities, thus enabling good rate performance. Furthermore, the superior ion transport kinetics reduce capacity decay during cycling, improving cycle stability. Finally, the superior ion transport kinetics also reduce the mass percentage of solid electrolyte and increase the mass percentage of Cu₂S in the cathode, leading to high energy density. Therefore, the solid-state battery cell of this invention combines high energy density, good cycle performance, and good rate performance.

[0008] In some embodiments, the copper ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X 1-c Including Cu6PS5Cl, Cu6PS5Br, Cu6PS5I, Cu6PS5Cl 0.5 Br 0.5 Cu 5.5 PS 4.5 Cl 1.5 Cu 5.5 PS 4.5 Br 1.5 One or more of them.

[0009] In some embodiments, the positive electrode active material includes Cu2S and CuI, wherein the mass percentage of CuI in the positive electrode active material is 1%-5%, optionally 3%-5%.

[0010] In some embodiments, the positive electrode active material comprises Cu2S and CuI, and the Cu2S and CuI in the positive electrode film are fused. After Cu2S and CuI are fused, they can better catalyze the conversion reaction between Cu2S and S (0 valence), further improving the kinetics of the conversion reaction.

[0011] In some embodiments, the positive electrode active material includes Cu₂S and the cuprous ion conductor Cu. 6+a+c P 1-a A a S 5- b+c B b X 1-c The copper ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X 1-c The mass percentage of the positive electrode active material is 1%-10%, optionally 5%-10%.

[0012] In some embodiments, the positive electrode active material includes Cu₂S and the cuprous ion conductor Cu. 6+a+c P 1-a A a S 5- b+c B b X 1-c The Cu2S in the positive electrode film and the cuprous ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X 1-c Fusion. Cu₂S and the cuprous ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X 1-c After fusion, the wettability of the solid-solid interface between Cu2S and the solid electrolyte in the cathode can be better improved, and the reduction of cuprous ions (Cu) can be reduced. + The energy barrier between Cu2S and the solid electrolyte allows solid-state battery cells to better combine high energy density, good cycle performance, and good rate performance.

[0013] In some embodiments, the positive electrode active material includes Cu₂S, CuI, and the cuprous ion conductor Cu. 6+a+c P 1-a A a S 5- b+c B b X 1-c CuI and the cuprous ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X 1-cThe total mass percentage of the positive electrode active material is 1%-15%, optionally 8%-15%.

[0014] In some embodiments, the positive electrode active material includes Cu₂S, CuI, and the cuprous ion conductor Cu. 6+a+c P 1-a A a S 5- b+c B b X 1-c The positive electrode film contains Cu₂S, CuI, and the cuprous ion conductor Cu. 6+a+c P 1-a A a S 5-b+c B b X 1-c Fusion. Cu₂S, CuI, and the cuprous ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X 1-c After fusion, it can better catalyze the conversion reaction between Cu2S and S (0 valence), further improving the kinetics of this conversion reaction; it can also better improve the solid-solid interface wettability between Cu2S and the solid electrolyte in the cathode, reducing the Cu content of cuprous ions. + The energy barrier between Cu2S and the solid electrolyte allows solid-state battery cells to better combine high energy density, good cycle performance, and good rate performance.

[0015] In some embodiments, Cu₂S accounts for more than 60% of the mass of the positive electrode film. This allows the solid-state battery cell to have a high energy density.

[0016] In some embodiments, the solid electrolyte accounts for 5%-28% of the mass of the positive electrode film.

[0017] In some embodiments, the sulfide electrolyte comprises Li 6+m+l P 1-m M m S 5-n+l N n Y 1-l The material, with the molecular formula Li 10±δ Ge 1-g G g P 2-q Q q S 12-w W w Materials, Li 4-v Ge 1-v P vOne or more of S4, Li2S-P2S5-based materials, Li2S-SiS2-based materials, Li2S-MeS-P2S5-based materials, LiGeGaS-based materials, where 0 ≤ m < 1, 0 ≤ n < 1, -1 < l < 1, M includes one or more elements selected from Ge, Si, Sn, Al, Zr, and Sb, N includes one or more elements selected from O, Se, and Te, Y includes one or more elements selected from Cl, Br, and I, 0 ≤ δ < 1, 0 ≤ g ≤ 1, 0 ≤ q ≤ 2, 0 ≤ w < 1, G includes one or two elements selected from Si and Sn, Q includes Sb, W includes one or more elements selected from O, Se, Te, Cl, Br, and I, 0 < l < 1, and Me includes one or more elements selected from Si, Ge, Sn, and Al.

[0018] In some embodiments, the halide electrolyte includes one or more of Li3InZ6, Li3YZ6, Li3ErZ6, where Z includes one or more elements selected from Cl, Br, and I.

[0019] In some embodiments, the solid electrolyte includes Li6PS5Cl, Li6PS5Br, Li6PS5I, Li6PS5Cl 0.5 Br 0.5 、Li 5.5 PS 4.5 Cl 1.5 、Li 5.5 PS 4.5 Br 1.5 、Li 10 GeP2S 12 、Li3PS4, Li7P3S 11 、Li 3.25 Ge 0.25 P 0.75 S4, Li6GaGe2S 10 、Li3InCl6, Li3InBr6, Li3YCl6, Li3YBr6, Li3ErCl6, or one or more of them.

[0020] In some embodiments, the electrolyte layer includes one or more of a sulfide electrolyte and a halide electrolyte.

[0021] In some embodiments, the negative electrode includes one or more of lithium, a lithium alloy, natural graphite, artificial graphite, mesocarbon microbeads, soft carbon, hard carbon, a silicon-based material, a tin-based material, lithium titanate, and a metal oxide.

[0022] In a second aspect, the present disclosure provides a battery device, which includes a plurality of solid-state battery monomers of the first aspect.

[0023] In a third aspect, the present disclosure provides an electrical device including the solid-state battery cell of the first aspect or the battery device of the second aspect.

[0024] In a fourth aspect, the present disclosure provides a positive electrode including a positive electrode film layer. The positive electrode film layer includes a positive electrode active material and a solid electrolyte. The positive electrode active material includes Cu2S, as well as one or more of CuI, cuprous ion conductor Cu 6+a+c P 1- a A a S 5-b+c B b X 1-c where 0 ≤ a < 1, 0 ≤ b < 1, -1 < c < 1, A includes one or more elements selected from Ge, Si, Sn, Al, Zr, and Sb, B includes one or more elements selected from O, Se, and Te, and X includes one or more elements selected from Cl, Br, and I; the solid electrolyte includes one or more of sulfide electrolytes and halide electrolytes. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] To more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following will briefly introduce the drawings required for use in the embodiments of the present disclosure. Obviously, the following described drawings are only some embodiments of the present disclosure. For those of ordinary skill in the art, other drawings can be obtained according to the drawings without creative efforts.

[0026] FIG. 1 shows a schematic diagram of a solid-state battery cell provided by some embodiments of the present disclosure.

[0027] FIG. 2 shows a schematic diagram of an electrical device provided by some embodiments of the present disclosure.

[0028] In the drawings, the drawings are not necessarily drawn to actual scale. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] Hereinafter, embodiments of the solid-state battery cell, battery device, electrical device, and positive electrode of the present disclosure will be specifically disclosed in detail with appropriate reference to the drawings. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there may be cases where detailed descriptions of well-known matters and repeated descriptions of actually identical structures are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the drawings and the following description are provided for those skilled in the art to fully understand the present disclosure and are not intended to limit the subject matter described in the claims.

[0030] The "range" disclosed in this disclosure is defined by a lower limit and an upper limit, whereby a given range is defined by selecting a lower limit and an upper limit, which define the boundaries of the particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also expected. Furthermore, if minimum range values ​​1 and 2 are listed, and if maximum range values ​​3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this disclosure, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0031] Unless otherwise specified, all embodiments and optional embodiments of this disclosure may be combined with each other to form new technical solutions, and such technical solutions should be considered as included in the disclosure of this disclosure.

[0032] Unless otherwise specified, all technical features and optional technical features of this disclosure can be combined to form new technical solutions, and such technical solutions should be considered as included in the disclosure of this disclosure.

[0033] Unless otherwise specified, all steps in this disclosure may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order; for example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0034] Unless otherwise specified, in this disclosure, the terms "first," "second," etc., are used to distinguish different objects, rather than to describe a specific order or primary / secondary relationship.

[0035] In this disclosure, the terms "multiple" or "a variety" refer to two or more kinds.

[0036] In the description of the embodiments of this disclosure, unless otherwise specified, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0037] Unless otherwise stated, the test temperature for all parameters mentioned in this disclosure is 25°C.

[0038] The solid-state battery cells mentioned in the embodiments of this disclosure can independently perform charging and discharging functions. Solid-state battery cells can be cylindrical, cuboid, or other shapes, and the embodiments of this disclosure are not limited in this respect. Figure 1 shows a cuboid solid-state battery cell 5 as an example.

[0039] The battery apparatus mentioned in the embodiments of this disclosure may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include multiple solid-state battery cells, which are connected in series, parallel, or mixed connections via busbars.

[0040] In some embodiments, a battery cell assembly is typically formed by arranging multiple solid-state battery cells.

[0041] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple solid-state battery cells together to form an independent module. As another example, a battery module can be formed by bundling multiple solid-state battery cells together with cable ties.

[0042] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cells housed within the housing.

[0043] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0044] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple solid-state battery cells to the housing.

[0045] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0046] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0047] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0048] The technical solutions described in this disclosure are applicable to various electrical devices that use solid-state battery cells or battery devices, such as, but not limited to, mobile devices (e.g., mobile phones, tablets, laptops, etc.), electric vehicles (e.g., pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc. Solid-state battery cells and battery devices are used to store or provide electrical energy.

[0049] Figure 2 is a schematic diagram of an example electrical device. This electrical device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc.

[0050] The solid-state battery cells disclosed herein may include coin cells, molded cells, hard-case cells, pouch cells, etc.

[0051] Solid-state battery cells using Cu₂S as the positive electrode active material are a relatively novel type of solid-state battery cell, which contains lithium ions (Li₂S). + Cuprous ions Cu + The phenomenon of co-migration, accompanied by the transfer of four electrons, results in high reversibility. The Cu₂S redox reaction has two stages: Stage 1, the redox reaction is Cu₂S = S + Cu + +2e - Cu₂S can reversibly convert to S (0 valence). This stage involves a change in the valence of S, accompanied by the transfer of two electrons, resulting in the cuprous ion Cu. + Lithium ions (Li) are transported to the solid electrolyte anion framework in the positive electrode. + The ion transport is completed at the negative electrode; in stage two, the redox reaction is Cu₂S + Li. + +2e -= Li2S + Cu, Cu2S is reversibly converted into Li2S and Cu. The valence change of Cu element occurs in this stage, accompanied by the transfer of two electrons. This stage can be completed only through the transport of lithium ions Li + transport.

[0052] In this solid-state battery monomer, since the valence change of S element is activated and the valence change of Cu element is retained, a four-electron conversion reaction can be achieved and it has a high theoretical capacity. However, the conversion reaction energy barrier from Cu2S to S(0 valence) is relatively high, resulting in poor kinetics of this conversion reaction; in addition, neither Cu2S nor S(0 valence) itself has the ionic conductivity characteristics of cuprous ion Cu + resulting in poor ionic transport kinetics of cuprous ion Cu + in Cu2S. Therefore, the solid-state battery monomer using Cu2S as the positive electrode active material has problems of insufficient cycle performance and rate performance. In addition, a high content of solid electrolyte is usually added to the positive electrode of this solid-state battery monomer, thereby reducing the mass ratio of Cu2S and reducing the energy density of the solid-state battery monomer.

[0053] In view of this, the embodiments of the present disclosure provide a positive electrode and a solid-state battery monomer including the same, and the solid-state battery monomer has both high energy density, good cycle performance and good rate performance.

[0054] The solid-state battery monomer provided by the embodiments of the present disclosure includes a positive electrode, an electrolyte layer and a negative electrode, and the electrolyte layer is located between the positive electrode and the negative electrode.

[0055] The positive electrode provided by the embodiments of the present disclosure includes a positive electrode film layer, and the positive electrode film layer includes a positive electrode active material and a solid electrolyte. The positive electrode active material includes Cu2S, and one or more of CuI, cuprous ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X 1-c where 0 ≤ a < 1, 0 ≤ b < 1, -1 < c < 1, A includes one or more elements of Ge, Si, Sn, Al, Zr and Sb, B includes one or more elements of O, Se and Te, and X includes one or more elements of Cl, Br and I. The solid electrolyte includes one or more of sulfide electrolytes and halide electrolytes.

[0056] The positive electrode active material of the present disclosure includes Cu2S, and one or more of CuI, cuprous ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X 1-cOne or more of these. CuI can catalyze the conversion reaction between Cu₂S and S (0 valence), enhancing the kinetics of this conversion reaction. Cu(II) is a cuprous ion conductor. 6+a+c P 1-a A a S 5-b+c B b X 1-c It has high ionic conductivity and can accelerate the reaction of Cu sub-cuprous ions in the positive electrode. + The transport of Cu2S ions enhances the transport of Cu2S ions. + Ion transport dynamics.

[0057] Therefore, the cathode disclosed herein possesses excellent ion transport kinetics. Good cathode ion transport kinetics allows the solid-state battery cell to maintain a high discharge capacity even at high current densities, thereby enabling the solid-state battery cell to exhibit good rate performance. Furthermore, good cathode ion transport kinetics can reduce capacity decay during cycling and improve the cycle stability of the solid-state battery cell. Finally, good cathode ion transport kinetics can reduce the mass proportion of solid electrolyte in the cathode and increase the mass proportion of Cu2S in the cathode, thereby enabling the solid-state battery cell to have high energy density.

[0058] Therefore, the solid-state battery cell disclosed herein can possess high energy density, good cycle performance, and good rate performance.

[0059] In some embodiments, the positive electrode active material includes Cu2S and CuI, and Cu2S and CuI in the positive electrode film are mixed or fused.

[0060] Optionally, the positive electrode active material includes Cu2S and CuI, and the Cu2S and CuI in the positive electrode film are fused together.

[0061] Mixing refers to different materials being dispersed but not fused together, while fusion refers to different materials being at least partially fused together.

[0062] The fusion of Cu2S and CuI can better catalyze the conversion reaction between Cu2S and S (0 valence), further improving the kinetics of the conversion reaction.

[0063] Optionally, the preparation method of the positive electrode active material includes the following steps: grinding and mixing Cu2S and CuI in a certain proportion, and annealing them under a protective gas atmosphere to obtain the positive electrode active material, wherein Cu2S and CuI are fused together.

[0064] Annealing is a heat treatment process in which the temperature is heated to a set temperature at a certain rate, held at that temperature for a period of time, and then cooled down at a certain rate.

[0065] Optionally, the heating rate of the annealing treatment can be 1℃ / min to 10℃ / min.

[0066] Optionally, the cooling rate of the annealing treatment can be 1℃ / min-10℃ / min, or the cooling process of the annealing treatment can be a furnace cooling process.

[0067] Optionally, the annealing temperature can be between 400℃ and 1000℃, for example, 400℃, 450℃, 500℃, 550℃, 600℃, 650℃, 700℃, 750℃, 800℃, 850℃, 900℃, 950℃, 1000℃, or any combination of the above values. More preferably, the annealing temperature can be 450℃-800℃, 450℃-700℃, or 450℃-600℃.

[0068] Optionally, the annealing time can be greater than or equal to 2 hours. Optionally, the annealing time can be between 2 hours and 48 hours, for example, it can be 2 hours, 4 hours, 6 hours, 8 hours, 10 hours, 12 hours, 14 hours, 16 hours, 18 hours, 20 hours, 22 hours, 24 hours, 26 hours, 28 hours, 30 hours, 32 hours, 34 hours, 36 hours, 38 hours, 40 hours, 42 hours, 44 hours, 46 hours, 48 ​​hours, or any range of the above values. Alternatively, the annealing time can be 6h-48h, 6h-42h, 6h-36h, 6h-30h, 6h-24h, 6h-18h, 8h-48h, 8h-42h, 8h-36h, 8h-30h, 8h-24h, 8h-18h, 10h-48h, 10h-42h, 10h-36h, 10h-30h, 10h-24h, or 10h-18h.

[0069] Annealing time refers to the time spent holding the temperature after heating to the set temperature, excluding the time for the heating and cooling stages.

[0070] Optionally, the protective gas may include one or more of argon, helium, and nitrogen.

[0071] In some embodiments, the positive electrode active material may include Cu2S and CuI, and the mass percentage of CuI in the positive electrode active material may be 1%-5%, for example, it may be 1%, 1.2%, 1.4%, 1.6%, 1.8%, 2%, 2.2%, 2.4%, 2.6%, 2.8%, 3%, 3.2%, 3.4%, 3.6%, 3.8%, 4%, 4.2%, 4.4%, 4.6%, 4.8%, 5%, or any range of the above values.

[0072] Increasing the mass percentage of CuI can further catalyze the conversion reaction between Cu₂S and S (0 valence), thereby improving the kinetics of this conversion reaction. However, if the mass percentage of CuI is too high, it will reduce the energy density of the solid-state battery cell. Therefore, by setting the mass percentage of CuI in the positive electrode active material to 1%-5%, solid-state battery cells can better combine high energy density, good cycle performance, and good rate performance.

[0073] Optionally, the mass percentage of CuI in the positive electrode active material can be 2%-5%, 3%-5%, or 4%-5%. This allows solid-state battery cells to better combine high energy density, good cycle performance, and good rate performance.

[0074] In some embodiments, the positive electrode active material includes Cu₂S and the cuprous ion conductor Cu. 6+a+c P 1-a A a S 5-b+c B b X 1-c Cu2S and cuprous ion conductor Cu in the positive electrode film 6+a+c P 1-a A a S 5-b+c B b X 1-c Mix or blend.

[0075] Optionally, the positive electrode active material includes Cu₂S and the cuprous ion conductor Cu. 6+a+c P 1-a A a S 5-b+c B b X 1-c Cu2S and cuprous ion conductor Cu in the positive electrode film 6+a+c P 1-a A a S 5-b+c B b X 1-c Integration.

[0076] Mixing refers to different materials being dispersed but not fused together, while fusion refers to different materials being at least partially fused together.

[0077] Cu₂S and the cuprous ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X 1-c After fusion, the wettability of the solid-solid interface between Cu2S and the solid electrolyte in the cathode can be better improved, and the reduction of cuprous ions (Cu) can be reduced. +The energy barrier between Cu2S and the solid electrolyte allows solid-state battery cells to better combine high energy density, good cycle performance, and good rate performance.

[0078] Optionally, the preparation method of the positive electrode active material includes the following steps: mixing Cu₂S and the cuprous ion conductor Cu 6+a+c P 1- a A a S 5-b+c B b X 1-c The materials are ground and mixed in a specific ratio, and then annealed under a protective gas atmosphere to obtain the positive electrode active material, in which Cu₂S and the cuprous ion conductor Cu are present. 6+a+c P 1-a A a S 5-b+c B b X 1-c Integration.

[0079] Annealing is a heat treatment process in which the temperature is heated to a set temperature at a certain rate, held at that temperature for a period of time, and then cooled down at a certain rate.

[0080] Optionally, the heating rate of the annealing treatment can be 1℃ / min to 10℃ / min.

[0081] Optionally, the cooling rate of the annealing treatment can be 1℃ / min-10℃ / min, or the cooling process of the annealing treatment can be a furnace cooling process.

[0082] Optionally, the annealing temperature can be between 400℃ and 1000℃, for example, 400℃, 450℃, 500℃, 550℃, 600℃, 650℃, 700℃, 750℃, 800℃, 850℃, 900℃, 950℃, 1000℃, or any combination of the above values. More preferably, the annealing temperature can be 450℃-800℃, 450℃-700℃, or 450℃-600℃.

[0083] Optionally, the annealing time can be greater than or equal to 2 hours. Optionally, the annealing time can be between 2 hours and 48 hours, for example, it can be 2 hours, 4 hours, 6 hours, 8 hours, 10 hours, 12 hours, 14 hours, 16 hours, 18 hours, 20 hours, 22 hours, 24 hours, 26 hours, 28 hours, 30 hours, 32 hours, 34 hours, 36 hours, 38 hours, 40 hours, 42 hours, 44 hours, 46 hours, 48 ​​hours, or any range of the above values. Alternatively, the annealing time can be 6h-48h, 6h-42h, 6h-36h, 6h-30h, 6h-24h, 6h-18h, 8h-48h, 8h-42h, 8h-36h, 8h-30h, 8h-24h, 8h-18h, 10h-48h, 10h-42h, 10h-36h, 10h-30h, 10h-24h, or 10h-18h.

[0084] Annealing time refers to the time spent holding the temperature after heating to the set temperature, excluding the time for the heating and cooling stages.

[0085] Optionally, the protective gas may include one or more of argon, helium, and nitrogen.

[0086] In some embodiments, the positive electrode active material may include Cu₂S and the cuprous ion conductor Cu. 6+a+c P 1-a A a S 5- b+c B b X 1-c Cu, a copper ion conductor 6+a+c P 1-a A a S 5-b+c B b X 1-c The mass percentage of the positive electrode active material can be 1%-10%, for example, it can be 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, or any combination of the above values.

[0087] Cuprous ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X 1-c The increased mass percentage of Cu2S can further enhance the concentration of copper subions (Cu). + The ion transport kinetics; however, the cuprous ion conductor Cu 6+a+c P 1-a A aS 5-b+c B b X 1-c When the mass ratio of Cu is too high, it will reduce the energy density of solid-state battery cells. Therefore, by making the copper ion conductor Cu... 6+a+c P 1-a A a S 5-b+c B b X 1- c A mass percentage of 1%-10% in the positive electrode active material can enable solid-state battery cells to better combine high energy density, good cycle performance, and good rate performance.

[0088] Optionally, the cuprous ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X 1-c The mass percentage of the positive electrode active material can be 2%-10%, 3%-10%, 4%-10%, 5%-10%, 6%-10%, 7%-10%, or 8%-10%. This allows solid-state battery cells to better combine high energy density, good cycle performance, and good rate performance.

[0089] In some embodiments, the positive electrode active material includes Cu₂S, CuI, and the cuprous ion conductor Cu. 6+a+c P 1-a A a S 5- b+c B b X 1-c The positive electrode film contains Cu₂S, CuI, and the cuprous ion conductor Cu. 6+a+c P 1-a A a S 5-b+c B b X 1-c Mix or blend.

[0090] Optionally, the positive electrode active material includes Cu₂S, CuI, and the cuprous ion conductor Cu. 6+a+c P 1-a A a S 5-b+c B b X 1-c The positive electrode film contains Cu₂S, CuI, and the cuprous ion conductor Cu. 6+a+c P 1-a A a S 5-b+c B b X 1-c Integration.

[0091] Mixing refers to different materials being dispersed but not fused together, while fusion refers to different materials being at least partially fused together.

[0092] Cu2S, CuI, and the cuprous ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X 1-c After fusion, it can better catalyze the conversion reaction between Cu2S and S (0 valence), further improving the kinetics of this conversion reaction; it can also better improve the solid-solid interface wettability between Cu2S and the solid electrolyte in the cathode, reducing the Cu content of cuprous ions. + The energy barrier between Cu2S and the solid electrolyte allows solid-state battery cells to better combine high energy density, good cycle performance, and good rate performance.

[0093] Optionally, the preparation method of the positive electrode active material includes the following steps: mixing Cu₂S, CuI, and the cuprous ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X 1-c The materials are ground and mixed in a specific ratio, and then annealed under a protective gas atmosphere to obtain the positive electrode active material, in which Cu₂S, CuI, and the cuprous ion conductor Cu are present. 6+a+c P 1-a A a S 5-b+c B b X 1-c Integration.

[0094] Annealing is a heat treatment process in which the temperature is heated to a set temperature at a certain rate, held at that temperature for a period of time, and then cooled down at a certain rate.

[0095] Optionally, the heating rate of the annealing treatment can be 1℃ / min to 10℃ / min.

[0096] Optionally, the cooling rate of the annealing treatment can be 1℃ / min-10℃ / min, or the cooling process of the annealing treatment can be a furnace cooling process.

[0097] Optionally, the annealing temperature can be between 400℃ and 1000℃, for example, 400℃, 450℃, 500℃, 550℃, 600℃, 650℃, 700℃, 750℃, 800℃, 850℃, 900℃, 950℃, 1000℃, or any combination of the above values. More preferably, the annealing temperature can be 450℃-800℃, 450℃-700℃, or 450℃-600℃.

[0098] Optionally, the annealing time can be greater than or equal to 2 hours. Optionally, the annealing time can be between 2 hours and 48 hours, for example, it can be 2 hours, 4 hours, 6 hours, 8 hours, 10 hours, 12 hours, 14 hours, 16 hours, 18 hours, 20 hours, 22 hours, 24 hours, 26 hours, 28 hours, 30 hours, 32 hours, 34 hours, 36 hours, 38 hours, 40 hours, 42 hours, 44 hours, 46 hours, 48 ​​hours, or any range of the above values. Alternatively, the annealing time can be 6h-48h, 6h-42h, 6h-36h, 6h-30h, 6h-24h, 6h-18h, 8h-48h, 8h-42h, 8h-36h, 8h-30h, 8h-24h, 8h-18h, 10h-48h, 10h-42h, 10h-36h, 10h-30h, 10h-24h, or 10h-18h.

[0099] Annealing time refers to the time spent holding the temperature after heating to the set temperature, excluding the time for the heating and cooling stages.

[0100] Optionally, the protective gas may include one or more of argon, helium, and nitrogen.

[0101] In some embodiments, the positive electrode active material may include Cu₂S, CuI, and the cuprous ion conductor Cu. 6+a+c P 1-a A a S 5- b+c B b X 1-c CuI and cuprous ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X 1-c The total mass percentage of the positive electrode active material can be 1%-15%, for example, it can be 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, 10.5%, 11%, 11.5%, 12%, 12.5%, 13%, 13.5%, 14%, 14.5%, 15%, or any combination of the above values.

[0102] CuI and the cuprous ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X 1-cThe increased mass percentage of Cu2S can further catalyze the conversion reaction between Cu2S and S (0 valence), further enhancing the kinetics of this conversion reaction, and further increasing the concentration of Cu(II) ions in Cu2S. + The ion transport kinetics of CuI and the cuprous ion conductor Cu; however, CuI and the cuprous ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X 1-c When the mass ratio of CuI is too high, it will reduce the energy density of solid-state battery cells. Therefore, by making CuI and the cuprous ion conductor Cu... 6+a+c P 1-a A a S 5-b+c B b X 1-c A total mass percentage of 1%-15% in the positive electrode active material can enable solid-state battery cells to better combine high energy density, good cycle performance, and good rate performance.

[0103] Optionally, CuI and the cuprous ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X 1-c The total mass percentage of the positive electrode active material can be 2%-15%, 3%-15%, 4%-15%, 5%-15%, 6%-15%, 7%-15%, 8%-15%, 9%-15%, 10%-15%, 11%-15%, or 12%-15%. This allows solid-state battery cells to better combine high energy density, good cycle performance, and good rate performance.

[0104] In some embodiments, the positive electrode active material may include Cu₂S, CuI, and the cuprous ion conductor Cu. 6+a+c P 1-a A a S 5- b+c B b X 1-c CuI and cuprous ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X 1-c The total mass percentage of CuI in the positive electrode active material can be 1%-15%, and the total mass percentage of CuI in the positive electrode active material can be greater than 0 and less than or equal to 5%. The cuprous ion conductor Cu... 6+a+c P 1-a A a S 5-b+c Bb X 1-c The total mass percentage of the positive electrode active material can be greater than 0 and less than or equal to 10%.

[0105] Optionally, CuI and the cuprous ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X 1-c The total mass percentage of CuI in the positive electrode active material can be 2%-15%, and the total mass percentage of CuI in the positive electrode active material can be 1%-5%. The cuprous ion conductor Cu... 6+a+c P 1-a A a S 5-b+c B b X 1-c The total mass percentage of the positive electrode active material can be 1%-10%.

[0106] Optionally, CuI and the cuprous ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X 1-c The total mass percentage of CuI in the positive electrode active material can be 8%-15%, and the total mass percentage of CuI in the positive electrode active material can be 3%-5%. The cuprous ion conductor Cu... 6+a+c P 1-a A a S 5-b+c B b X 1-c The total mass percentage of the positive electrode active material can be 5%-10%.

[0107] Optionally, CuI and the cuprous ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X 1-c The total mass percentage of CuI in the positive electrode active material can be 12%-15%, and the total mass percentage of CuI in the positive electrode active material can be 4%-5%. The cuprous ion conductor Cu... 6+a+c P 1-a A a S 5-b+c B b X 1-c The total mass percentage of the positive electrode active material can be 8%-10%.

[0108] This allows solid-state battery cells to better combine high energy density, good cycle performance, and good rate performance.

[0109] In some embodiments, the copper ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X 1-c It can be Cu 6+c PS 5+c X 1-c .

[0110] In some embodiments, the copper ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X 1-c It can include Cu6PS5Cl, Cu6PS5Br, Cu6PS5I, Cu6PS5Cl 0.5 Br 0.5 Cu 5.5 PS 4.5 Cl 1.5 Cu 5.5 PS 4.5 Br 1.5 One or more of them.

[0111] The cathode disclosed herein has good ion transport kinetics. Good ion transport kinetics can reduce the mass ratio of solid electrolyte in the cathode and increase the mass ratio of Cu2S in the cathode, thereby enabling solid-state battery cells to have high energy density.

[0112] In some embodiments, the mass percentage of Cu2S in the positive electrode film layer can be greater than 60%. Optionally, the mass percentage of Cu2S in the positive electrode film layer can be greater than or equal to 62% or greater than or equal to 65%.

[0113] The positive electrode film layer includes a solid electrolyte. In some embodiments, the mass percentage of the solid electrolyte in the positive electrode film layer can be 5%-28%, for example, it can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, or any combination of the above values.

[0114] Optionally, the mass percentage of the solid electrolyte in the positive electrode film can be 6%-28%, 8%-28%, 10%-28%, 12%-28%, 14%-28%, 16%-28%, 6%-25%, 8%-25%, 10%-25%, 12%-25%, 14%-25%, or 16%-25%.

[0115] The positive electrode film layer includes a solid electrolyte, and the solid electrolyte includes one or more of sulfide electrolytes and halide electrolytes. In some embodiments, the sulfide electrolyte may include a material with the molecular formula Li 6+m+l P 1-m M m S 5-n+l N n Y 1-l -type materials, materials with the molecular formula Li 10±δ Ge<{0000421}>G g P 2-q Q q S 12-w W w -type materials, Li 4-v [[]]Ge 1-v P v S4, Li2S-P2S5-based materials, Li2S-SiS2-based materials, Li2S-MeS-P2S5-based materials, LiGeGaS-based materials, etc., where 0 ≤ m < ¹, 0 ≤ n < ¹, -¹ < l < ¹, M includes one or more elements of Ge, Si, Sn, Al, Zr, and Sb, N includes one or more elements of O, Se, and Te, Y includes one or more elements of Cl, Br, and I, 0 ≤ δ < ¹, 0 ≤ g ≤ ¹, 0 ≤ q ≤ ², 0 ≤ w < ¹, G includes one or two elements of Si and Sn, Q includes Sb, W includes one or more elements of O, Se, Te, Cl, Br, and I, 0 < l < ¹, and Me includes one or more of Si, Ge, Sn, and Al. In some embodiments, the halide electrolyte may include one or more of Li3InZ6, Li3YZ6, and Li3ErZ6, where Z includes one or more elements of Cl, Br, and I.

[0116] Optionally, the solid electrolyte may include a material with the molecular formula Li 6+m+l P 1-m M m S 5-n+l N n Y [[ID=4q]] 1-l -type materials, materials with the molecular formula Li 10±δ Ge<00{00437}> G g P 2-q Q q S [[ID=5q]] 12-w W w -type materials. <00008s4> As an example, the solid electrolyte may include Li6PS5Cl, Li6PS5Br, Li6PS5I, Li6PS5Cl 0.5 Br 0.5 -, Li 5.5 PS4.5 Cl 1.5 Li 5.5 PS 4.5 Br 1.5 Li 10 GeP2S 12 Li3PS4, Li7P3S 11 Li 3.25 Ge 0.25 P 0.75 S4, Li6GaGe2S 10 The electrolyte may be one or more of the following: Li3InCl6, Li3InBr6, Li3YCl6, Li3YBr6, and Li3ErCl6. Optionally, the solid electrolyte may include Li6PS5Cl, Li6PS5Br, Li6PS5I, and Li6PS5Cl. 0.5 Br 0.5 Li 5.5 PS 4.5 Cl 1.5 Li 5.5 PS 4.5 Br 1.5 Li 10 GeP2S 12 One or more of them.

[0118] In some embodiments, the positive electrode film layer further includes a positive electrode conductive agent.

[0119] Optionally, the positive electrode conductive agent may be one or more of the following, including but not limited to superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes (CNTs), graphene, carbon nanofibers, and vapor-grown carbon fibers (VGCF).

[0120] In some embodiments, the positive electrode film layer may or may not include a positive electrode binder, and can be adjusted according to the positive electrode composition and the preparation process of the solid-state battery cell.

[0121] Optionally, the positive electrode binder may include, but is not limited to, one or more of the following: polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene-propylene terpolymer, ethylene-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, methyl vinyl silicone rubber, nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), thermoplastic styrene-butadiene rubber (SBS), isoprene rubber, cis-butadiene rubber (BR), ethyl cellulose, fluororubber, and acrylate rubber.

[0122] In some embodiments, the positive electrode further includes a positive current collector, and the positive electrode film layer is located on at least one surface of the positive current collector. The positive current collector has two surfaces opposite each other in its thickness direction, and the positive electrode film layer is disposed on either or both of the two opposite surfaces of the positive current collector.

[0123] In some embodiments, the positive current collector may be a metal foil or a composite current collector. The metal foil may be a pure metal, an alloy, or a surface-treated metal, such as, but not limited to, stainless steel foil, carbon-coated aluminum foil, or aluminum foil. The composite current collector may include a polymer substrate and a metal layer formed on at least one surface of the polymer substrate. As an example, the metal layer may include, but is not limited to, one or more of aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. As an example, the polymer substrate may include, but is not limited to, one or more of polypropylene, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene.

[0124] In some embodiments, the positive electrode may not require an additional positive current collector; for example, the stainless steel sheet of the mold battery can be directly used as the positive current collector.

[0125] The positive electrode can be prepared by either a dry process or a wet process.

[0126] [Electrolyte layer]

[0127] In some embodiments, the electrolyte layer may include one or more of a sulfide electrolyte and a halide electrolyte.

[0128] Optionally, the sulfide electrolyte may include Li 6+m+l P 1-m M m S 5-n+l N n Y 1-l The material, with the molecular formula Li 10±δ Ge 1-g G g P 2-q Q q S 12-w W w Materials, Li 4-v Ge 1-v P vOne or more of S4, Li2S-P2S5-based materials, Li2S-SiS2-based materials, Li2S-MeS-P2S5-based materials, LiGeGaS-based materials, where 0 ≤ m < 1, 0 ≤ n < 1, -1 < l < 1, M includes one or more elements among Ge, Si, Sn, Al, Zr, and Sb, N includes one or more elements among O, Se, and Te, Y includes one or more elements among Cl, Br, and I, 0 ≤ δ < 1, 0 ≤ g ≤ 1, 0 ≤ q ≤ 2, 0 ≤ w < 1, G includes one or two elements among Si and Sn, Q includes Sb, W includes one or more elements among O, Se, Te, Cl, Br, and I, 0 < l < 1, and Me includes one or more elements among Si, Ge, Sn, and Al.

[0129] Optionally, the halide electrolyte may include one or more of Li3InZ6, Li3YZ6, Li3ErZ6, where Z includes one or more elements among Cl, Br, and I.

[0130] Optionally, the electrolyte layer may include a material with the formula Li 6+m+l P 1-m M m S 5-n+l N n Y 1-l and a material with the formula Li 10±δ Ge 1-g G g P 2-q Q q S 12-w W w or one or more of such materials.

[0131] As an example, the electrolyte layer may include Li6PS5Cl, Li6PS5Br, Li6PS5I, Li6PS5Cl 0.5 Br 0.5 , Li 5.5 PS 4.5 Cl 1.5 , Li 5.5 PS 4.5 Br 1.5 , Li 10 GeP2S 12 , Li3PS4, Li7P3S 11 , Li 3.25 Ge 0.25 P 0.75 S4, Li6GaGe2S 10The electrolyte layer may be one or more of the following: Li3InCl6, Li3InBr6, Li3YCl6, Li3YBr6, and Li3ErCl6. Optionally, the electrolyte layer may include Li6PS5Cl, Li6PS5Br, Li6PS5I, and Li6PS5Cl. 0.5 Br 0.5 Li 5.5 PS 4.5 Cl 1.5 Li 5.5 PS 4.5 Br 1.5 Li 10 GeP2S 12 One or more of them.

[0132] In some embodiments, the electrolyte layer may or may not include a binder, depending on the manufacturing process of the solid-state battery cell. Optionally, the binder may include, but is not limited to, one or more of the following: polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene-propylene terpolymer, ethylene-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, methyl vinyl silicone rubber, nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), thermoplastic styrene-butadiene rubber (SBS), isoprene rubber, butadiene rubber (BR), ethyl cellulose, fluororubber, and acrylate rubber.

[0133] The electrolyte layer can be prepared by a dry process or a wet process.

[0134] [negative electrode]

[0135] In some embodiments, the negative electrode may include one or more of lithium, lithium alloy, natural graphite, artificial graphite, mesophase micro carbon spheres, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, and metal oxides.

[0136] In some embodiments, the negative electrode can be a metal sheet, such as a lithium sheet or a lithium alloy sheet.

[0137] Optionally, the mass fraction of lithium in the lithium alloy sheet can be above 90%.

[0138] Optionally, other elements in the lithium alloy sheet may include, but are not limited to, one or more of In, Mg, Al, Zn, Sn, Ag, Au, Ga, Pt, and Fe.

[0139] Alternatively, the lithium alloy sheet may include, but is not limited to, InLi alloy sheet, Li-Mg alloy sheet, Li-Al alloy sheet, Li-Zn alloy sheet, Li-Fe alloy sheet, etc.

[0140] In some embodiments, the negative electrode may include a negative electrode current collector and a lithium-based metal layer located on at least one surface of the negative electrode current collector. The lithium-based metal layer may be metallic lithium or a lithium alloy. The negative electrode current collector has two surfaces opposite each other in its thickness direction, and the lithium-based metal layer is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0141] Optionally, the mass fraction of lithium in the lithium alloy can be above 90%.

[0142] Optionally, other elements in the lithium alloy may include, but are not limited to, one or more of In, Mg, Al, Zn, Sn, Ag, Au, Ga, Pt, and Fe.

[0143] Alternatively, the lithium alloy may include, but is not limited to, InLi alloy, Li-Mg alloy, Li-Al alloy, Li-Zn alloy, Li-Fe alloy, etc.

[0144] In some embodiments, the negative electrode may include a negative electrode current collector and a negative electrode film layer located on at least one surface of the negative electrode current collector, the negative electrode film layer including a negative electrode active material. The negative electrode current collector has two surfaces opposite to each other in its thickness direction, and the negative electrode film layer is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0145] In some embodiments, the negative electrode active material may include, but is not limited to, one or more of natural graphite, artificial graphite, mesophase micro carbon spheres, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, and metal oxides.

[0146] Optionally, the silicon-based material may include, but is not limited to, one or more of elemental silicon, silicon oxide, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Optionally, the tin-based material may include, but is not limited to, one or more of elemental tin, tin oxide, and tin alloys. Optionally, the metal oxide may include, but is not limited to, one or more of TiO2, MoO2, In2O3, Al2O3, Cu2O, VO2, Ga2O3, Sb2O5, and Bi2O5.

[0147] In some embodiments, the negative electrode film layer may also include a negative electrode binder, or it may not include a negative electrode binder, which can be adjusted according to the negative electrode composition and the preparation process of the solid-state battery cell.

[0148] Optionally, the negative electrode binder may include, but is not limited to, one or more of the following: styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, polyacrylic acid, polymethacrylic acid, sodium polyacrylate, polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA) and carboxymethyl chitosan (CMCS), methyl vinyl silicone rubber, nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), thermoplastic styrene-butadiene rubber (SBS), isoprene rubber, cis-butadiene rubber (BR), ethyl cellulose, fluororubber, and acrylate rubber.

[0149] In some embodiments, the negative electrode film layer may or may not include a negative electrode conductive agent.

[0150] Optionally, the negative electrode conductive agent may be one or more of the following, including but not limited to superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes (CNTs), graphene, carbon nanofibers, and vapor-grown carbon fibers (VGCF).

[0151] In some embodiments, the negative electrode film layer may or may not include a solid electrolyte. Optionally, the solid electrolyte may include one or more of a sulfide electrolyte and a halide electrolyte.

[0152] Optionally, the sulfide electrolyte may include Li 6+m+l P 1-m M m S 5-n+l N n Y 1-l The material, with the molecular formula Li 10±δ Ge 1-g G g P 2-q Q q S 12-w W w Materials, Li 4-v Ge 1-v P vOne or more of S4, Li2S-P2S5-based materials, Li2S-SiS2-based materials, Li2S-MeS-P2S5-based materials, LiGeGaS-based materials, where 0 ≤ m < 1, 0 ≤ n < 1, -1 < l < 1, M includes one or more elements among Ge, Si, Sn, Al, Zr, and Sb, N includes one or more elements among O, Se, and Te, Y includes one or more elements among Cl, Br, and I, 0 ≤ δ < 1, 0 ≤ g ≤ 1, 0 ≤ q ≤ 2, 0 ≤ w < 1, G includes one or two elements among Si and Sn, Q includes Sb, W includes one or more elements among O, Se, Te, Cl, Br, and I, 0 < l < 1, and Me includes one or more elements among Si, Ge, Sn, and Al. Optionally, the halide electrolyte may include one or more of Li3InZ6, Li3YZ6, Li3ErZ6, where Z includes one or more elements among Cl, Br, and I.

[0153] Optionally, the solid electrolyte may include a material with the molecular formula Li 6+m+l P 1-m M m S 5-n+l N n Y 1-l and a material with the molecular formula Li 10±δ Ge 1-g G g P 2-q Q q S 12-w W w or more.

[0154] As an example, the solid electrolyte may include Li6PS5Cl, Li6PS5Br, Li6PS5I, Li6PS5Cl 0.5 Br 0.5 Li 5.5 PS 4.5 Cl 1.5 Li 5.5 PS 4.5 Br 1.5 Li 10 GeP2S 12 Li3PS4, Li7P3S 11 Li 3.25 Ge 0.25 P 0.75 S4, Li6GaGe2S 10 Li3InCl6, Li3InBr6, Li3YCl6, Li3YBr6, Li3ErCl6, or more. Optionally, the solid electrolyte may include Li6PS5Cl, Li6PS5Br, Li6PS5I, Li6PS5Cl0.5 Br 0.5 Li 5.5 PS 4.5 Cl 1.5 Li 5.5 PS 4.5 Br 1.5 Li 10 GeP2S 12 One or more of them.

[0155] In some embodiments, the negative electrode current collector may be a metal foil or a composite current collector. The metal foil may be a pure metal, an alloy, or a surface-treated metal, such as, but not limited to, stainless steel foil, copper foil, and nickel foil. The composite current collector may include a polymer substrate and a metal layer formed on at least one surface of the polymer substrate. As an example, the metal layer may include, but is not limited to, one or more of copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. As an example, the polymer substrate may include, but is not limited to, one or more of polypropylene, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene, and polyethylene.

[0156] The negative electrode does not require an additional negative current collector; for example, the stainless steel sheet of a mold battery can be used directly as the negative current collector.

[0157] The negative electrode can be prepared by either a dry process or a wet process.

[0158] In some embodiments, the solid-state battery cell may further include an outer packaging for accommodating the electrode assembly formed by assembling the negative electrode, electrolyte layer, and positive electrode. The outer packaging may be a rigid shell, such as a hard plastic shell, aluminum shell, or steel shell. The outer packaging may also be a flexible package, such as a pouch. The material of the flexible package may be plastic, such as one or more of aluminum-plastic film, polypropylene, polybutylene terephthalate (PBT), and polybutylene succinate (PBS).

[0159] [Preparation Method]

[0160] The methods for preparing solid-state battery cells are well known. For example, the assembly methods of solid-state battery cells include, but are not limited to, coin cells, mold cells, hard-case cells, and pouch cells.

[0161] Example

[0162] The following embodiments describe the disclosure of this disclosure in more detail. These embodiments are merely illustrative, as various modifications and variations will be apparent to those skilled in the art within the scope of this disclosure. Unless otherwise stated, all parts, percentages, and ratios reported in the following embodiments are based on mass, and all reagents used in the embodiments are commercially available or synthesized by conventional methods and can be used directly without further processing, and the instruments used in the embodiments are commercially available.

[0163] Comparative Example 1

[0164] Composite cathode powder was obtained by grinding and mixing Cu2S, a positive electrode active material, Li6PS5Cl, a sulfide electrolyte, and vapor-grown carbon fiber (VGCF), a positive electrode conductive agent, at a mass ratio of 75:20:5.

[0165] Solid-state battery cells are assembled using a 10mm diameter solid-state battery mold: 100mg of sulfide electrolyte Li6PS5Cl is added to the solid-state battery mold and pressed into an electrolyte layer; then 100mg of Li6PS5Cl-indium powder mixture is added to one side of the electrolyte layer, pressed into a sheet, and then a 50μm thick lithium foil is applied and pressed together; then 5mg of the above composite cathode powder is added to the other side of the electrolyte layer, pressed into a sheet, and finally the solid-state battery mold is pressurized to obtain a solid-state battery cell.

[0166] Example 1

[0167] Cu2S, P2S5, and CuCl were ground and mixed in a certain proportion, and then annealed at 550℃ for 12 hours under Ar atmosphere protection to obtain Cu6PS5Cl.

[0168] Cu2S, Cu6PS5Cl, and CuI were ground and mixed in a mass ratio of 85:10:5 and annealed at 550℃ for 12 hours under Ar atmosphere protection to obtain the positive electrode active material. Cu2S, Cu6PS5Cl, and CuI were fused to form the positive electrode active material, and the total mass ratio of Cu6PS5Cl and CuI in the positive electrode active material was 15%.

[0169] The above-prepared positive electrode active material, sulfide electrolyte Li6PS5Cl, and positive electrode conductive agent vapor-grown carbon fiber (VGCF) were ground and mixed at a mass ratio of 75:20:5 to obtain composite positive electrode powder.

[0170] Solid-state battery cells are assembled using a 10mm diameter solid-state battery mold: 100mg of sulfide electrolyte Li6PS5Cl is added to the solid-state battery mold and pressed into an electrolyte layer; then 100mg of Li6PS5Cl-indium powder mixture is added to one side of the electrolyte layer, pressed into a sheet, and then a 50μm thick lithium foil is applied and pressed together; then 5mg of the above composite cathode powder is added to the other side of the electrolyte layer, pressed into a sheet, and finally the solid-state battery mold is pressurized to obtain a solid-state battery cell.

[0171] Example 2

[0172] Cu2S, P2S5, and CuCl were ground and mixed in a certain proportion, and then annealed at 550℃ for 12 hours under Ar atmosphere protection to obtain Cu6PS5Cl.

[0173] Cu2S and Cu6PS5Cl were ground and mixed at a mass ratio of 90:10, and annealed at 550℃ for 12 hours under Ar atmosphere protection to obtain the positive electrode active material. Cu2S and Cu6PS5Cl were fused to form the positive electrode active material, and the mass ratio of Cu6PS5Cl in the positive electrode active material was 10%.

[0174] The above-prepared positive electrode active material, sulfide electrolyte Li6PS5Cl, and positive electrode conductive agent vapor-grown carbon fiber (VGCF) were ground and mixed at a mass ratio of 75:20:5 to obtain composite positive electrode powder.

[0175] Solid-state battery cells are assembled using a 10mm diameter solid-state battery mold: 100mg of sulfide electrolyte Li6PS5Cl is added to the solid-state battery mold and pressed into an electrolyte layer; then 100mg of Li6PS5Cl-indium powder mixture is added to one side of the electrolyte layer, pressed into a sheet, and then a 50μm thick lithium foil is applied and pressed together; then 5mg of the above composite cathode powder is added to the other side of the electrolyte layer, pressed into a sheet, and finally the solid-state battery mold is pressurized to obtain a solid-state battery cell.

[0176] Example 3

[0177] Cu2S, P2S5, and CuCl were ground and mixed in a certain proportion, and then annealed at 550℃ for 12 hours under Ar atmosphere protection to obtain Cu6PS5Cl.

[0178] A composite cathode powder was obtained by grinding and mixing a mixture of positive electrode active materials Cu2S and Cu6PS5Cl with sulfide electrolyte Li6PS5Cl and positive electrode conductive agent vapor-grown carbon fiber (VGCF) at a mass ratio of 67.5:7.5:20:5. The mass percentage of Cu6PS5Cl in the positive electrode active materials was 10%.

[0179] Solid-state battery cells are assembled using a 10mm diameter solid-state battery mold: 100mg of sulfide electrolyte Li6PS5Cl is added to the solid-state battery mold and pressed into an electrolyte layer; then 100mg of Li6PS5Cl-indium powder mixture is added to one side of the electrolyte layer, pressed into a sheet, and then a 50μm thick lithium foil is applied and pressed together; then 5mg of the above composite cathode powder is added to the other side of the electrolyte layer, pressed into a sheet, and finally the solid-state battery mold is pressurized to obtain a solid-state battery cell.

[0180] Example 4

[0181] A composite cathode powder was obtained by grinding and mixing a mixture of positive electrode active materials Cu2S and CuI with a sulfide electrolyte Li6PS5Cl and a positive electrode conductive agent vapor-grown carbon fiber (VGCF) at a mass ratio of 71.25:3.75:20:5. The mass percentage of CuI in the positive electrode active materials was 5%.

[0182] Solid-state battery cells are assembled using a 10mm diameter solid-state battery mold: 100mg of sulfide electrolyte Li6PS5Cl is added to the solid-state battery mold and pressed into an electrolyte layer; then 100mg of Li6PS5Cl-indium powder mixture is added to one side of the electrolyte layer, pressed into a sheet, and then a 50μm thick lithium foil is applied and pressed together; then 5mg of the above composite cathode powder is added to the other side of the electrolyte layer, pressed into a sheet, and finally the solid-state battery mold is pressurized to obtain a solid-state battery cell.

[0183] Performance testing

[0184] (1) Cyclic performance test of solid-state battery cells

[0185] At 25°C, solid-state battery cells were charged to 3.0V at a current density of 0.5C (vs. Li). + / Li), let stand for 10 minutes, then discharge to 1.0V at a current density of 0.5C (vs. Li). + The discharge capacity at this point is denoted as C1. Following the above charge-discharge process, the solid-state battery cell is cycled 500 times at a current density of 0.5C. The discharge capacity at this point is denoted as C2. The capacity retention rate of the solid-state battery cell after 500 cycles is calculated as C2 / C1 × 100%. The larger this value, the better the cycle performance of the solid-state battery cell.

[0186] (2) Rate performance test of solid-state battery cells

[0187] At 25°C, solid-state battery cells were charged to 3.0V (vs. Li) at a current density of 0.1C. + / Li), let stand for 10 minutes, then discharge to 1.0V at a current density of 0.1C (vs. Li). + / Li), and 5 charge-discharge cycles were performed to obtain the discharge capacity at a 0.1C rate; subsequently, the solid-state battery cells were charged to 3.0V (vs. Li) at a current density of 0.2C. + / Li), let stand for 10 minutes, then discharge to 1.0V at a current density of 0.2C (vs. Li). + The solid-state battery cells were cycled 5 times (Li) to obtain the discharge capacity at a rate of 0.2C; subsequently, the solid-state battery cells were charged to 3.0V (vs. Li) at a current density of 0.5C. + / Li), let stand for 10 minutes, then discharge to 1.0V at a current density of 0.5C (vs. Li). + / Li), and 5 charge-discharge cycles were performed to obtain the discharge capacity at a 0.5C rate; then the solid-state battery cells were charged to 3.0V (vs. Li) at a 1C current density. + / Li), let stand for 10 minutes, then discharge at a current density of 1C to 1.0V (vs. Li). + / Li), and 5 charge-discharge cycles were performed to obtain the discharge capacity at a 1C rate; then the solid-state battery cells were charged to 3.0V (vs. Li) at a 2C current density. + / Li), let stand for 10 minutes, then discharge to 1.0V at a current density of 2C (vs. Li). + / Li), and the discharge capacity at 2C rate was obtained by 5 cycles of charge and discharge.

[0188] The rate performance of a solid-state battery cell is characterized by the ratio of its discharge capacity at 2C to its discharge capacity at 0.1C. The larger this value, the better the rate performance of the solid-state battery cell.

[0189] Table 1

[0190] The test results from Examples 1 to 4 and Comparative Example 1 show that by including Cu2S, CuI, and the cuprous ion conductor Cu in the positive electrode active material, 6+a+c P 1-a A a S 5-b+c B b X 1-c One or more of these can improve the cycle performance and rate performance of solid-state battery cells. CuI can catalyze the conversion reaction between Cu₂S and S (0 valence), improving the kinetics of this conversion reaction; the cuprous ion conductor Cu 6+a+c P 1-a A a S5-b+c B b X 1-c It has high ionic conductivity and can accelerate the reaction of Cu sub-cuprous ions in the positive electrode. + The transport of Cu2S ions enhances the transport of Cu2S ions. + Ion transport dynamics.

[0191] The test results from Examples 1 to 4 show that by making CuI and / or the cuprous ion conductor Cu 6+a+c P 1-a A a S 5- b+c B b X 1-c When fused with Cu2S to form a positive electrode active material, it can further improve the cycle performance and rate performance of solid-state battery cells.

[0192] The test results from Examples 1 and 2 show that by making CuI and the cuprous ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X 1-c The fusion of Cu₂S with Cu₂S to form a positive electrode active material can further improve the cycle performance and rate performance of solid-state battery cells. This not only enhances the conversion reaction kinetics between Cu₂S and S (0 valence), but also improves the interfacial wettability between Cu₂S and Li₆PS₅Cl, accelerating the reaction of cuprous ions (Cu₂S, Cu ... + The transmission.

[0193] Example 2-1

[0194] Cu2S, P2S5, and CuCl were ground and mixed in a certain proportion, and then annealed at 550℃ for 12 hours under Ar atmosphere protection to obtain Cu6PS5Cl.

[0195] Cu2S and Cu6PS5Cl were ground and mixed at a mass ratio of 92:8, and annealed at 550℃ for 12 hours under Ar atmosphere protection to obtain the positive electrode active material. Cu2S and Cu6PS5Cl were fused to form the positive electrode active material, and the mass ratio of Cu6PS5Cl in the positive electrode active material was 8%.

[0196] The above-prepared positive electrode active material, sulfide electrolyte Li6PS5Cl, and positive electrode conductive agent vapor-grown carbon fiber (VGCF) were ground and mixed at a mass ratio of 75:20:5 to obtain composite positive electrode powder.

[0197] Solid-state battery cells are assembled using a 10mm diameter solid-state battery mold: 100mg of sulfide electrolyte Li6PS5Cl is added to the solid-state battery mold and pressed into an electrolyte layer; then 100mg of Li6PS5Cl-indium powder mixture is added to one side of the electrolyte layer, pressed into a sheet, and then a 50μm thick lithium foil is applied and pressed together; then 5mg of the above composite cathode powder is added to the other side of the electrolyte layer, pressed into a sheet, and finally the solid-state battery mold is pressurized to obtain a solid-state battery cell.

[0198] Example 2-2

[0199] Cu2S, P2S5, and CuCl were ground and mixed in a certain proportion, and then annealed at 550℃ for 12 hours under Ar atmosphere protection to obtain Cu6PS5Cl.

[0200] Cu2S and Cu6PS5Cl were ground and mixed at a mass ratio of 95:5, and annealed at 550℃ for 12 hours under Ar atmosphere protection to obtain the positive electrode active material. Cu2S and Cu6PS5Cl were fused to form the positive electrode active material, and the mass percentage of Cu6PS5Cl in the positive electrode active material was 5%.

[0201] The above-prepared positive electrode active material, sulfide electrolyte Li6PS5Cl, and positive electrode conductive agent vapor-grown carbon fiber (VGCF) were ground and mixed at a mass ratio of 75:20:5 to obtain composite positive electrode powder.

[0202] Solid-state battery cells are assembled using a 10mm diameter solid-state battery mold: 100mg of sulfide electrolyte Li6PS5Cl is added to the solid-state battery mold and pressed into an electrolyte layer; then 100mg of Li6PS5Cl-indium powder mixture is added to one side of the electrolyte layer, pressed into a sheet, and then a 50μm thick lithium foil is applied and pressed together; then 5mg of the above composite cathode powder is added to the other side of the electrolyte layer, pressed into a sheet, and finally the solid-state battery mold is pressurized to obtain a solid-state battery cell.

[0203] Example 2-3

[0204] Cu2S, P2S5, and CuCl were ground and mixed in a certain proportion, and then annealed at 550℃ for 12 hours under Ar atmosphere protection to obtain Cu6PS5Cl.

[0205] Cu2S and Cu6PS5Cl were ground and mixed at a mass ratio of 98:2, and annealed at 550℃ for 12 hours under Ar atmosphere protection to obtain the positive electrode active material. Cu2S and Cu6PS5Cl were fused to form the positive electrode active material, and the mass ratio of Cu6PS5Cl in the positive electrode active material was 2%.

[0206] The above-prepared positive electrode active material, sulfide electrolyte Li6PS5Cl, and positive electrode conductive agent vapor-grown carbon fiber (VGCF) were ground and mixed at a mass ratio of 75:20:5 to obtain composite positive electrode powder.

[0207] Solid-state battery cells are assembled using a 10mm diameter solid-state battery mold: 100mg of sulfide electrolyte Li6PS5Cl is added to the solid-state battery mold and pressed into an electrolyte layer; then 100mg of Li6PS5Cl-indium powder mixture is added to one side of the electrolyte layer, pressed into a sheet, and then a 50μm thick lithium foil is applied and pressed together; then 5mg of the above composite cathode powder is added to the other side of the electrolyte layer, pressed into a sheet, and finally the solid-state battery mold is pressurized to obtain a solid-state battery cell.

[0208] Examples 2-4

[0209] Cu2S, P2S5, and CuCl were ground and mixed in a certain proportion, and then annealed at 550℃ for 12 hours under Ar atmosphere protection to obtain Cu6PS5Cl.

[0210] Cu2S and Cu6PS5Cl were ground and mixed at a mass ratio of 99:1, and annealed at 550℃ for 12 hours under Ar atmosphere protection to obtain the positive electrode active material. Cu2S and Cu6PS5Cl were fused to form the positive electrode active material, and the mass percentage of Cu6PS5Cl in the positive electrode active material was 1%.

[0211] The above-prepared positive electrode active material, sulfide electrolyte Li6PS5Cl, and positive electrode conductive agent vapor-grown carbon fiber (VGCF) were ground and mixed at a mass ratio of 75:20:5 to obtain composite positive electrode powder.

[0212] Solid-state battery cells are assembled using a 10mm diameter solid-state battery mold: 100mg of sulfide electrolyte Li6PS5Cl is added to the solid-state battery mold and pressed into an electrolyte layer; then 100mg of Li6PS5Cl-indium powder mixture is added to one side of the electrolyte layer, pressed into a sheet, and then a 50μm thick lithium foil is applied and pressed together; then 5mg of the above composite cathode powder is added to the other side of the electrolyte layer, pressed into a sheet, and finally the solid-state battery mold is pressurized to obtain a solid-state battery cell.

[0213] Examples 2-5

[0214] Cu2S, P2S5, and CuCl were ground and mixed in a certain proportion, and then annealed at 550℃ for 12 hours under Ar atmosphere protection to obtain Cu6PS5Cl.

[0215] Cu2S and Cu6PS5Cl were ground and mixed at a mass ratio of 88:12, and annealed at 550℃ for 12 hours under Ar atmosphere protection to obtain the positive electrode active material. Cu2S and Cu6PS5Cl were fused to form the positive electrode active material, and the mass ratio of Cu6PS5Cl in the positive electrode active material was 12%.

[0216] The above-prepared positive electrode active material, sulfide electrolyte Li6PS5Cl, and positive electrode conductive agent vapor-grown carbon fiber (VGCF) were ground and mixed at a mass ratio of 75:20:5 to obtain composite positive electrode powder.

[0217] Solid-state battery cells are assembled using a 10mm diameter solid-state battery mold: 100mg of sulfide electrolyte Li6PS5Cl is added to the solid-state battery mold and pressed into an electrolyte layer; then 100mg of Li6PS5Cl-indium powder mixture is added to one side of the electrolyte layer, pressed into a sheet, and then a 50μm thick lithium foil is applied and pressed together; then 5mg of the above composite cathode powder is added to the other side of the electrolyte layer, pressed into a sheet, and finally the solid-state battery mold is pressurized to obtain a solid-state battery cell.

[0218] Table 2

[0219] As shown in Table 2, increasing the mass percentage of Cu6PS5Cl in the positive electrode active material can improve the cycle performance and rate performance of solid-state battery cells. However, once the mass percentage of Cu6PS5Cl in the positive electrode active material reaches 10%, further increasing the mass percentage of Cu6PS5Cl in the positive electrode active material will not significantly improve the cycle performance and rate performance of solid-state battery cells, and will also reduce the energy density of solid-state battery cells.

[0220] Example 3-1

[0221] Cu2S, P2S5, and CuCl were ground and mixed in a certain proportion, and then annealed at 550℃ for 12 hours under Ar atmosphere protection to obtain Cu6PS5Cl.

[0222] A composite cathode powder was obtained by grinding and mixing a mixture of positive electrode active materials Cu2S and Cu6PS5Cl with sulfide electrolyte Li6PS5Cl and positive electrode conductive agent vapor-grown carbon fiber (VGCF) at a mass ratio of 69:6:20:5. The mass percentage of Cu6PS5Cl in the positive electrode active materials was 8%.

[0223] Solid-state battery cells are assembled using a 10mm diameter solid-state battery mold: 100mg of sulfide electrolyte Li6PS5Cl is added to the solid-state battery mold and pressed into an electrolyte layer; then 100mg of Li6PS5Cl-indium powder mixture is added to one side of the electrolyte layer, pressed into a sheet, and then a 50μm thick lithium foil is applied and pressed together; then 5mg of the above composite cathode powder is added to the other side of the electrolyte layer, pressed into a sheet, and finally the solid-state battery mold is pressurized to obtain a solid-state battery cell.

[0224] Example 3-2

[0225] Cu2S, P2S5, and CuCl were ground and mixed in a certain proportion, and then annealed at 550℃ for 12 hours under Ar atmosphere protection to obtain Cu6PS5Cl.

[0226] A composite cathode powder was obtained by grinding and mixing a mixture of positive electrode active materials Cu2S and Cu6PS5Cl with sulfide electrolyte Li6PS5Cl and positive electrode conductive agent vapor-grown carbon fiber (VGCF) at a mass ratio of 71.25:3.75:20:5. The mass percentage of Cu6PS5Cl in the positive electrode active materials was 5%.

[0227] Solid-state battery cells are assembled using a 10mm diameter solid-state battery mold: 100mg of sulfide electrolyte Li6PS5Cl is added to the solid-state battery mold and pressed into an electrolyte layer; then 100mg of Li6PS5Cl-indium powder mixture is added to one side of the electrolyte layer, pressed into a sheet, and then a 50μm thick lithium foil is applied and pressed together; then 5mg of the above composite cathode powder is added to the other side of the electrolyte layer, pressed into a sheet, and finally the solid-state battery mold is pressurized to obtain a solid-state battery cell.

[0228] Example 3-3

[0229] Cu2S, P2S5, and CuCl were ground and mixed in a certain proportion, and then annealed at 550℃ for 12 hours under Ar atmosphere protection to obtain Cu6PS5Cl.

[0230] A composite cathode powder was obtained by grinding and mixing a mixture of positive electrode active materials Cu2S and Cu6PS5Cl with sulfide electrolyte Li6PS5Cl and positive electrode conductive agent vapor-grown carbon fiber (VGCF) at a mass ratio of 73.5:1.5:20:5. The mass percentage of Cu6PS5Cl in the positive electrode active materials was 2%.

[0231] Solid-state battery cells are assembled using a 10mm diameter solid-state battery mold: 100mg of sulfide electrolyte Li6PS5Cl is added to the solid-state battery mold and pressed into an electrolyte layer; then 100mg of Li6PS5Cl-indium powder mixture is added to one side of the electrolyte layer, pressed into a sheet, and then a 50μm thick lithium foil is applied and pressed together; then 5mg of the above composite cathode powder is added to the other side of the electrolyte layer, pressed into a sheet, and finally the solid-state battery mold is pressurized to obtain a solid-state battery cell.

[0232] Examples 3-4

[0233] Cu2S, P2S5, and CuCl were ground and mixed in a certain proportion, and then annealed at 550℃ for 12 hours under Ar atmosphere protection to obtain Cu6PS5Cl.

[0234] A composite cathode powder was obtained by grinding and mixing a mixture of positive electrode active materials Cu2S and Cu6PS5Cl with sulfide electrolyte Li6PS5Cl and positive electrode conductive agent vapor-grown carbon fiber (VGCF) at a mass ratio of 74.25:0.75:20:5. The mass percentage of Cu6PS5Cl in the positive electrode active materials was 1%.

[0235] Solid-state battery cells are assembled using a 10mm diameter solid-state battery mold: 100mg of sulfide electrolyte Li6PS5Cl is added to the solid-state battery mold and pressed into an electrolyte layer; then 100mg of Li6PS5Cl-indium powder mixture is added to one side of the electrolyte layer, pressed into a sheet, and then a 50μm thick lithium foil is applied and pressed together; then 5mg of the above composite cathode powder is added to the other side of the electrolyte layer, pressed into a sheet, and finally the solid-state battery mold is pressurized to obtain a solid-state battery cell.

[0236] Examples 3-5

[0237] Cu2S, P2S5, and CuCl were ground and mixed in a certain proportion, and then annealed at 550℃ for 12 hours under Ar atmosphere protection to obtain Cu6PS5Cl.

[0238] A composite cathode powder was obtained by grinding and mixing a mixture of positive electrode active materials Cu2S and Cu6PS5Cl with sulfide electrolyte Li6PS5Cl and positive electrode conductive agent vapor-grown carbon fiber (VGCF) at a mass ratio of 66:9:20:5. The mass percentage of Cu6PS5Cl in the positive electrode active materials was 12%.

[0239] Solid-state battery cells are assembled using a 10mm diameter solid-state battery mold: 100mg of sulfide electrolyte Li6PS5Cl is added to the solid-state battery mold and pressed into an electrolyte layer; then 100mg of Li6PS5Cl-indium powder mixture is added to one side of the electrolyte layer, pressed into a sheet, and then a 50μm thick lithium foil is applied and pressed together; then 5mg of the above composite cathode powder is added to the other side of the electrolyte layer, pressed into a sheet, and finally the solid-state battery mold is pressurized to obtain a solid-state battery cell.

[0240] Table 3

[0241] As shown in Table 3, increasing the mass percentage of Cu6PS5Cl in the positive electrode active material can improve the cycle performance and rate performance of solid-state battery cells. However, once the mass percentage of Cu6PS5Cl in the positive electrode active material reaches 10%, further increasing the mass percentage of Cu6PS5Cl in the positive electrode active material will not significantly improve the cycle performance and rate performance of solid-state battery cells, and will also reduce the energy density of solid-state battery cells.

[0242] Example 4-1

[0243] A composite cathode powder was obtained by grinding and mixing a mixture of positive electrode active materials Cu2S and CuI with a sulfide electrolyte Li6PS5Cl and a positive electrode conductive agent vapor-grown carbon fiber (VGCF) at a mass ratio of 72:3:20:5. The mass percentage of CuI in the positive electrode active materials was 4%.

[0244] Solid-state battery cells are assembled using a 10mm diameter solid-state battery mold: 100mg of sulfide electrolyte Li6PS5Cl is added to the solid-state battery mold and pressed into an electrolyte layer; then 100mg of Li6PS5Cl-indium powder mixture is added to one side of the electrolyte layer, pressed into a sheet, and then a 50μm thick lithium foil is applied and pressed together; then 5mg of the above composite cathode powder is added to the other side of the electrolyte layer, pressed into a sheet, and finally the solid-state battery mold is pressurized to obtain a solid-state battery cell.

[0245] Example 4-2

[0246] A composite cathode powder was obtained by grinding and mixing a mixture of positive electrode active materials Cu2S and CuI with a sulfide electrolyte Li6PS5Cl and a positive electrode conductive agent vapor-grown carbon fiber (VGCF) at a mass ratio of 72.75:2.25:20:5. The mass percentage of CuI in the positive electrode active materials was 3%.

[0247] Solid-state battery cells are assembled using a 10mm diameter solid-state battery mold: 100mg of sulfide electrolyte Li6PS5Cl is added to the solid-state battery mold and pressed into an electrolyte layer; then 100mg of Li6PS5Cl-indium powder mixture is added to one side of the electrolyte layer, pressed into a sheet, and then a 50μm thick lithium foil is applied and pressed together; then 5mg of the above composite cathode powder is added to the other side of the electrolyte layer, pressed into a sheet, and finally the solid-state battery mold is pressurized to obtain a solid-state battery cell.

[0248] Example 4-3

[0249] A composite cathode powder was obtained by grinding and mixing a mixture of positive electrode active materials Cu2S and CuI with a sulfide electrolyte Li6PS5Cl and a positive electrode conductive agent vapor-grown carbon fiber (VGCF) at a mass ratio of 73.5:1.5:20:5. The mass percentage of CuI in the positive electrode active materials was 2%.

[0250] Solid-state battery cells are assembled using a 10mm diameter solid-state battery mold: 100mg of sulfide electrolyte Li6PS5Cl is added to the solid-state battery mold and pressed into an electrolyte layer; then 100mg of Li6PS5Cl-indium powder mixture is added to one side of the electrolyte layer, pressed into a sheet, and then a 50μm thick lithium foil is applied and pressed together; then 5mg of the above composite cathode powder is added to the other side of the electrolyte layer, pressed into a sheet, and finally the solid-state battery mold is pressurized to obtain a solid-state battery cell.

[0251] Example 4-4

[0252] A composite cathode powder was obtained by grinding and mixing a mixture of positive electrode active materials Cu2S and CuI with a sulfide electrolyte Li6PS5Cl and a positive electrode conductive agent vapor-grown carbon fiber (VGCF) at a mass ratio of 74.25:0.75:20:5. The mass percentage of CuI in the positive electrode active materials was 1%.

[0253] Solid-state battery cells are assembled using a 10mm diameter solid-state battery mold: 100mg of sulfide electrolyte Li6PS5Cl is added to the solid-state battery mold and pressed into an electrolyte layer; then 100mg of Li6PS5Cl-indium powder mixture is added to one side of the electrolyte layer, pressed into a sheet, and then a 50μm thick lithium foil is applied and pressed together; then 5mg of the above composite cathode powder is added to the other side of the electrolyte layer, pressed into a sheet, and finally the solid-state battery mold is pressurized to obtain a solid-state battery cell.

[0254] Examples 4-5

[0255] A composite cathode powder was obtained by grinding and mixing a mixture of positive electrode active materials Cu2S and CuI with a sulfide electrolyte Li6PS5Cl and a positive electrode conductive agent vapor-grown carbon fiber (VGCF) at a mass ratio of 69:6:20:5. The mass percentage of CuI in the positive electrode active materials was 8%.

[0256] Solid-state battery cells are assembled using a 10mm diameter solid-state battery mold: 100mg of sulfide electrolyte Li6PS5Cl is added to the solid-state battery mold and pressed into an electrolyte layer; then 100mg of Li6PS5Cl-indium powder mixture is added to one side of the electrolyte layer, pressed into a sheet, and then a 50μm thick lithium foil is applied and pressed together; then 5mg of the above composite cathode powder is added to the other side of the electrolyte layer, pressed into a sheet, and finally the solid-state battery mold is pressurized to obtain a solid-state battery cell.

[0257] Table 4

[0258] As shown in Table 4, increasing the mass percentage of CuI in the positive electrode active material can improve the cycle performance and rate performance of solid-state battery cells. However, once the mass percentage of CuI in the positive electrode active material reaches 5%, further increasing the mass percentage of CuI in the positive electrode active material will not have a significant effect on improving the cycle performance and rate performance of solid-state battery cells, and will also reduce the energy density of solid-state battery cells.

[0259] It should be noted that this disclosure is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this disclosure are included within the technical scope of this disclosure. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, are also included within the scope of this disclosure without departing from the spirit of this disclosure.

Claims

1. A solid-state battery cell, comprising a positive electrode, an electrolyte layer, and a negative electrode, wherein the electrolyte layer is located between the positive electrode and the negative electrode, wherein, The positive electrode includes a positive electrode film layer, the positive electrode film layer includes a positive electrode active material and a solid electrolyte, the positive electrode active material includes Cu2S, and one or more of CuI, cuprous ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X 1-c or more, 0 ≤ a < 1, 0 ≤ b < 1, -1 < c < 1, A includes one or more elements selected from Ge, Si, Sn, Al, Zr, and Sb, B includes one or more elements selected from O, Se, and Te, and X includes one or more elements selected from Cl, Br, and I; The solid electrolyte includes one or more of sulfide electrolytes and halide electrolytes.

2. The solid-state battery cell according to claim 1, wherein, The copper ion conductor Cu 6+a+c P 1-a A a S 5- b+c B b X 1-c Including Cu6PS5Cl, Cu6PS5Br, Cu6PS5I, Cu6PS5Cl 0.5 Br 0.5 Cu 5.5 PS 4.5 Cl 1.5 Cu 5.5 PS 4.5 Br 1.5 One or more of them.

3. The solid-state battery cell according to any one of claims 1-2, wherein, The positive electrode active material includes Cu2S and CuI, with CuI accounting for 1%-5% of the total mass of the positive electrode active material.

4. The solid-state battery cell according to claim 3, wherein, The mass percentage of CuI in the positive electrode active material is 3%-5%.

5. The solid-state battery cell according to any one of claims 1-4, wherein, The positive electrode active material includes Cu2S and CuI, and the Cu2S and CuI in the positive electrode film are fused together.

6. The solid-state battery cell according to any one of claims 1-2, wherein, The positive electrode active material includes Cu₂S and the cuprous ion conductor Cu. 6+a+c P 1-a A a S 5-b+c B b X 1-c The copper ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X 1-c The mass percentage of the positive electrode active material is 1%-10%.

7. The solid-state battery cell according to claim 6, wherein, The copper ion conductor Cu 6+a+c P 1-a A a S 5- b+c B b X 1-c The mass percentage of the positive electrode active material is 5%-10%.

8. The solid-state battery cell according to any one of claims 1-2 and 6-7, wherein, The positive electrode active material includes Cu₂S and the cuprous ion conductor Cu. 6+a+c P 1-a A a S 5-b+c B b X 1-c The Cu2S in the positive electrode film and the cuprous ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X 1-c Integration.

9. The solid-state battery cell according to any one of claims 1-2, wherein, The positive electrode active material includes Cu₂S, CuI, and the cuprous ion conductor Cu. 6+a+c P 1-a A a S 5-b+c B b X 1-c CuI and the cuprous ion conductor Cu 6+a+c P 1- a A a S 5-b+c B b X 1-c The total mass percentage of the positive electrode active material is 1%-15%.

10. The solid-state battery cell according to claim 9, wherein, CuI and the cuprous ion conductor Cu 6+a+c P 1- a A a S 5-b+c B b X 1-c The total mass percentage of the positive electrode active material is 8%-15%.

11. The solid-state battery cell according to any one of claims 1-2 and 9-10, wherein, The positive electrode active material includes Cu₂S, CuI, and the cuprous ion conductor Cu. 6+a+c P 1-a A a S 5-b+c B b X 1-c The positive electrode film contains Cu₂S, CuI, and the cuprous ion conductor Cu. 6+a+c P 1-a A a S 5-b+c B b X 1-c Integration.

12. The solid-state battery cell according to any one of claims 1-11, wherein, Cu2S accounts for more than 60% of the mass of the positive electrode film; and / or, The solid electrolyte accounts for 5%-28% of the mass of the positive electrode film.

13. The solid-state battery cell according to any one of claims 1-12, wherein, The sulfide electrolyte includes a material with the molecular formula Li 6+m+l P 1-m M m S 5-n+l N n Y 1-l a material with the molecular formula Li 10±δ Ge 1- g G g P 2-q Q q S 12-w W w Li 4-v Ge 1-v P v S4, Li2S - P2S5 - type materials, Li2S - SiS2 - type materials, Li2S - MeS - P2S5 - type materials, LiGeGaS - type materials, or one or more of them, where 0 ≤ m < 1, 0 ≤ n < 1, - 1 < l < 1, M includes one or more elements selected from Ge, Si, Sn, Al, Zr, and Sb, N includes one or more elements selected from O, Se, and Te, Y includes one or more elements selected from Cl, Br, and I, 0 ≤ δ < ⒈ 0 ≤ g ≤ 1, 0 ≤ q ≤ 2, 0 ≤ w < 1, G includes one or two elements selected from Si and Sn, Q includes Sb, W includes one or more elements selected from O, Se, Te, Cl, Br, and I, 0 < l < 1, Me includes one or more elements selected from Si, Ge, Sn, and Al; and / or, The halide electrolyte includes one or more of Li3InZ6, Li3YZ6, and Li3ErZ6, where Z includes one or more of Cl, Br, and I.

14. The solid-state battery cell according to any one of claims 1-13, wherein, The solid electrolyte includes Li6PS5Cl, Li6PS5Br, Li6PS5I, and Li6PS5Cl. 0.5 Br 0.5 Li 5.5 PS 4.5 Cl 1.5 Li 5.5 PS 4.5 Br 1.5 Li 10 GeP2S 12 Li3PS4, Li7P3S 11 Li 3.25 Ge 0.25 P 0.75 S4, Li6GaGe2S 10 One or more of Li3InCl6, Li3InBr6, Li3YCl6, Li3YBr6, and Li3ErCl6.

15. The solid-state battery cell according to any one of claims 1-14, wherein, The electrolyte layer includes one or more of sulfide electrolytes and halide electrolytes; and / or, The negative electrode includes one or more of lithium, lithium alloy, natural graphite, artificial graphite, mesophase micro carbon spheres, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, and metal oxides.

16. A battery device comprising a plurality of solid-state battery cells as described in any one of claims 1-15.

17. An electrical device comprising a solid-state battery cell as described in any one of claims 1-15 or a battery device as described in claim 16.

18. A positive electrode, wherein, The positive electrode includes a positive electrode film layer, the positive electrode film layer includes a positive electrode active material and a solid electrolyte, the positive electrode active material includes Cu2S, and one or more of CuI, cuprous ion conductor Cu 6+a+c P 1-a A a S 5-b+c B b X 1-c or more of them, 0 ≤ a < 1, 0 ≤ b < 1, -1 < c < 1, A includes one or more elements of Ge, Si, Sn, Al, Zr, and Sb, B includes one or more elements of O, Se, and Te, and X includes one or more elements of Cl, Br, and I; The solid electrolyte includes one or more of sulfide electrolytes and halide electrolytes.

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