Anode sheet, solid-state battery cell, battery device, electric device, anode active material and method of manufacturing the same.

Abstract

The present disclosure provides an anode sheet, a solid-state battery cell, a battery device, an electric device, an anode active material, and a method for manufacturing the same. The anode sheet comprises an anode active material and a sulfide solid electrolyte material. The anode active material comprises a matrix material, a cobalt-rich material located on the surface of the matrix material, and a coating material located on at least a portion of the surface of the cobalt-rich material. The matrix material comprises a transition metal oxide, and the cobalt-rich material comprises a transition metal oxide containing Co. The molar content of the Co element in the cobalt-rich material is greater than the molar content of the Co element in the matrix material. The coating material comprises an electrolyte salt material. When the anode sheet is applied to a solid-state battery cell, the capacity decay rate at high temperatures of the solid-state battery cell can be reduced and high-temperature cycle performance improved.

Description

Technology Field

[0001] The present disclosure relates to an anode sheet, a solid-state battery cell, a battery device, an electric device, an anode active material, and a method for manufacturing the same.

[0002] [Cross-reference of related applications]

[0003] This application claims priority to Chinese patent application 202411215789.2, filed on August 30, 2024, titled "anode sheet, solid-state battery cell, battery device, electric device, anode active material and method of manufacturing the same," the entire contents of said application are incorporated herein by reference. Background Technology

[0004] Compared to liquid battery cells, solid-state battery cells use solid electrolyte materials, so situations such as combustion or explosion do not easily occur, resulting in higher reliability. However, solid-state battery cells have a problem where their capacity rapidly degrades at high temperatures.

[0005] The present disclosure provides an anode sheet, a solid-state battery cell, a battery device, an electric device, an anode active material, and a method for manufacturing the same. When the anode sheet is applied to a solid-state battery cell, the capacity decay rate at high temperatures of the solid-state battery cell can be reduced and high-temperature cycle performance can be improved.

[0006] In a first embodiment, the present disclosure provides an anode sheet, wherein the anode sheet comprises an anode active material and a sulfide solid electrolyte material, and the anode active material comprises a matrix material, a cobalt-rich material located on the surface of the matrix material, and a coating material located on at least a portion of the surface of the cobalt-rich material; the matrix material comprises a transition metal oxide, and the cobalt-rich material comprises a transition metal oxide containing Co, wherein the molar content of the Co element in the cobalt-rich material is greater than the molar content of the Co element in the matrix material; and the coating material comprises an electrolyte salt material.

[0007] The cathode active material of the present disclosure comprises a cobalt-rich material located on the surface of a matrix material and a coating material located on at least a portion of the surface of the cobalt-rich material. Since the matrix material comprises a transition metal oxide and the cobalt-rich material comprises a transition metal oxide containing Co, the cobalt-rich material and the matrix material have better affinity and structural compatibility, thereby improving the overall structural stability of the cathode active material; furthermore, since the molar content of the Co element in the cobalt-rich material is greater than the molar content of the Co element in the matrix material, the cobalt-rich material located on the surface of the matrix material mitigates the decomposition of the sulfide solid electrolyte material by the matrix material, thereby improving the interfacial stability between the cathode active material and the sulfide solid electrolyte material. The coating material comprises an electrolyte salt material, and since the elastic modulus of the electrolyte salt material is much smaller than the elastic modulus of the matrix material, a coating over a larger area can be realized, thereby further reducing side reactions between the matrix material and the sulfide solid electrolyte material. Accordingly, since the anode sheet of the present disclosure exhibits good high-temperature stability between the anode active material and the sulfide solid electrolyte material, applying the anode sheet to a solid battery cell can reduce the capacity decay rate at high temperatures of the solid battery cell and improve high-temperature cycle performance.

[0008] In some embodiments, the coating material comprises a fluorine-containing electrolyte salt material. The fluorine-containing electrolyte salt material has better high-temperature stability and high-pressure stability, and can decompose before the sulfide solid electrolyte material during the charging process to produce LiF, thereby reducing the decomposition of the sulfide solid electrolyte material, improving the high-temperature stability of the cathode active material and the sulfide solid electrolyte material, reducing the capacity decay rate at high temperatures of the solid-state battery cell, and improving high-temperature cycle performance.

[0009] In some embodiments, the coating material comprises one or more of Li2PO2F2, lithium difluoro(oxalate)borate, lithium difluorodi(oxalate)phosphate, and lithium tetrafluoro(oxalate)phosphate. Within the above range, the coating material can decompose before the sulfide solid electrolyte material to produce LiF and be coated on the surface of the cobalt-rich material, thereby reducing the decomposition of the sulfide solid electrolyte material and improving the high-temperature stability of the cathode active material and the sulfide solid electrolyte material. Additionally, the high-temperature cycle performance of the solid-state battery cell can be further improved by enabling the cathode active material to have high ionic electrical conductivity. Furthermore, since the elastic modulus of this coating material is low, a coating over a larger area can be realized, thereby further reducing side reactions between the matrix material and the sulfide solid electrolyte material.

[0010] In some embodiments, when the total mass of the positive active material is calculated as 100%, the mass fraction of the coating material is 0.1% to 3%. Since the mass fraction of the coating material is within the above range, the positive active material can have high ionic electrical conductivity and high specific capacity.

[0011] In some embodiments, the coating material is located on 90% to 100% of the surface of the cobalt-rich material. Accordingly, side reactions between the matrix material and the sulfide solid electrolyte material can be further reduced, thereby reducing the capacity decay rate of the solid battery cell at high temperatures and improving high-temperature cycle performance.

[0012] In some embodiments, the thickness range of the cobalt-rich material is 0.5 nm to 50 nm. Since the thickness of the cobalt-rich material is within the above range, not only can the high-temperature stability of the cathode active material and the sulfide solid electrolyte material be improved, but the cathode active material can also have a higher specific capacity.

[0013] In some embodiments, the matrix material comprises one or more of lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, and lithium-rich manganese-based materials.

[0014] In some embodiments, the cobalt-rich material comprises one or more of cobalt-rich lithium nickel cobalt manganese oxide, cobalt-rich lithium nickel cobalt aluminum oxide, and cobalt-rich lithium-rich manganese-based materials.

[0015] In some embodiments, the matrix material comprises a transition metal oxide containing Ni, and the cobalt-rich material comprises a transition metal oxide containing Ni and Co, wherein the molar content of the Ni element in the cobalt-rich material is smaller than the molar content of the Ni element in the matrix material. Accordingly, the solid-state battery cell can be designed to accommodate both high energy density and good high-temperature cycling performance.

[0016] In some embodiments, the cobalt-rich material is located on 100% of the surface of the matrix material.

[0017] In some embodiments, there is no interface between the cobalt-rich material and the matrix material. Since there is no interface between the cobalt-rich material and the matrix material, the cobalt-rich material and the matrix material can have better affinity and structural compatibility, which can further improve the overall structural stability of the cathode active material.

[0018] In some embodiments, the positive electrode active material further comprises metal particles located between the cobalt-rich material and the coating material, and the metal particles comprise one or more of cobalt metal particles and cobalt oxide particles.

[0019] In some embodiments, the average particle size of the positive active material is 3 μm to 10 μm.

[0020] In some embodiments, the average particle size of the sulfide solid electrolyte material is 1 nm to 20 μm.

[0021] In some embodiments, the mass ratio of the positive active material to the sulfide solid electrolyte material is 99:1 to 70:30. Since the mass ratio of the positive active material to the sulfide solid electrolyte material is within the above range, the solid battery cell can have high energy density, high ion transport characteristics, and good cycle performance.

[0022] In some embodiments, the anode sheet further comprises an anode conductive agent and / or an anode binder.

[0023] In some embodiments, the anode sheet further comprises an anode current collector, and the anode active material and the sulfide solid electrolyte material are located on at least one surface of the anode current collector.

[0024] In a second embodiment, the present disclosure provides a solid-state battery cell comprising a cathode sheet, a solid electrolyte membrane, and an anode sheet according to a first embodiment, wherein the solid electrolyte membrane is positioned between the cathode sheet and the anode sheet.

[0025] In some embodiments, the cathode sheet comprises one or more of lithium, lithium alloy, natural graphite, artificial graphite, mesocarbon micro beads, soft carbon, hard carbon, silicon-based material, tin-based material, lithium titanate, and metal oxide.

[0026] In some embodiments, the solid electrolyte membrane comprises one or more of a sulfide solid electrolyte material, a halogen solid electrolyte material, and an oxide solid electrolyte material.

[0027] In a third embodiment, the present disclosure provides a battery device comprising a plurality of solid-state battery cells according to a second embodiment.

[0028] In a fourth embodiment, the present disclosure provides an electric device comprising a solid-state battery cell according to a second embodiment or a battery device according to a third embodiment.

[0029] In a fifth embodiment, the present disclosure provides a positive electrode active material, wherein the positive electrode active material comprises a matrix material, a cobalt-rich material located on the surface of the matrix material, and a coating material located on at least a portion of the surface of the cobalt-rich material; the matrix material comprises a transition metal oxide, the cobalt-rich material comprises a transition metal oxide containing Co, and the molar content of the Co element in the cobalt-rich material is greater than the molar content of the Co element in the matrix material; and the coating material comprises an electrolyte salt material.

[0030] In a sixth aspect, the present disclosure provides a method for manufacturing an anode active material comprising the steps of: providing a coating material comprising a matrix material including a transition metal oxide, a cobalt raw material, and an electrolyte salt material; mixing the matrix material and the cobalt raw material and performing a first heat treatment in an oxygen-containing atmosphere to obtain an intermediate material; mixing the obtained intermediate material and the coating material and performing a second heat treatment in an oxygen-containing atmosphere to obtain an anode active material, wherein the anode active material comprises a matrix material, a cobalt-rich material located on the surface of the matrix material, and a coating material located on at least a portion of the surface of the cobalt-rich material, wherein the matrix material comprises a transition metal oxide, the cobalt-rich material comprises a transition metal oxide containing Co, the molar content of the Co element in the cobalt-rich material is greater than the molar content of the Co element in the matrix material, and the coating material comprises an electrolyte salt material.

[0031] In some embodiments, the temperature of the first heat treatment is 500°C to 800°C.

[0032] In some embodiments, the time of the first heat treatment is 0.5h to 10h.

[0033] In some embodiments, the temperature of the secondary heat treatment is 300°C to 400°C.

[0034] In some embodiments, the time for the second heat treatment is 0.5h to 5h.

[0035] In some embodiments, the cobalt raw material includes one or more of cobalt hydroxide and cobalt oxide. Brief explanation of the drawing

[0036] To further clarify the technical methods of the embodiments of the present disclosure, the accompanying drawings used in the embodiments of the present disclosure are briefly introduced below. The accompanying drawings described below are merely some embodiments of the present disclosure, and it will be obvious to a person skilled in the art that other drawings can be obtained from the accompanying drawings without creative effort. FIG. 1 is a schematic diagram of a solid-state battery cell provided in one embodiment of the present disclosure. FIG. 2 is a schematic diagram of an electric device provided in one embodiment of the present disclosure. FIG. 3 is a schematic diagram of the structure of a positive electrode active material provided in one embodiment of the present disclosure. In the drawing, the drawing is not drawn in actual proportions. Specific details for implementing the invention

[0037] Hereinafter, specific embodiments of the anode sheet, solid-state battery cell, battery device, electric device, anode active material, and method of manufacturing the same according to the present disclosure will be described in detail with appropriate reference to the accompanying drawings. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of known matters and repetitive descriptions of structures that are actually identical may be omitted. This is intended to prevent the following description from becoming unnecessarily long and to enable those skilled in the art to understand it easily. Furthermore, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure and are not intended to limit the subject matter described in the claims.

[0038] The “range” disclosed in this disclosure is limited in the form of lower and upper limits, and a given range is limited by selecting one lower limit and one upper limit, and the selected lower limit and upper limit define the boundaries of a specific range. A range limited in this way may or may not include end values ​​and may be arbitrarily combined, that is, any lower limit may be combined with any upper limit to form a range. For example, if ranges of 60 to 120 and 80 to 110 are listed for a specific parameter, it is understood that ranges of 60 to 110 and 80 to 120 are also expected. Additionally, if minimum range values ​​1 and 2 are listed and maximum range values ​​3, 4 and 5 are listed, ranges such as 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4, and 2 to 5 may all be expected. In the present disclosure, unless otherwise described, the numerical range “a to b” represents an abbreviated expression of any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range “0 to 5” indicates that all real numbers between “0 to 5” are listed in the present specification, and “0 to 5” is merely an abbreviated expression of a combination of such numbers. Additionally, if a parameter is represented as an integer ≥ 2, this corresponds to disclosing that the parameter is, for example, an integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0039] Unless otherwise specified, all embodiments of the present disclosure and selectable embodiments may be combined with one another to form new technical solutions, and such technical solutions shall be deemed to be included in the content of the present disclosure.

[0040] Unless otherwise specified, all technical features and selectable technical features of the present disclosure may be combined with one another to form new technical solutions, and such technical solutions shall be deemed to be included in the content of the present disclosure.

[0041] Unless otherwise specified, all steps of the present disclosure may proceed sequentially or randomly, preferably sequentially. For example, “the method comprises steps (a) and (b)” indicates that the method may comprise steps (a) and (b) performed sequentially, or steps (b) and (a) performed sequentially. For example, where it is stated that “the method may further comprise step (c)”, this indicates that step (c) may be added to the method in any order, for example, the method may comprise steps (a), (b), and (c), steps (a), (c), and (b), or steps (c), (a), and (b), etc.

[0042] Unless otherwise specified, terms such as "first," "second," etc. in this disclosure are used to distinguish different objects and are not intended to describe a specific order or priority relationship.

[0043] In this disclosure, the terms "multiple" and "multiple types" mean two or more.

[0044] In the description of the embodiments disclosed herein, unless otherwise specified, a first feature being located "above" or "below" a second feature may mean that the first feature and the second feature are in direct contact, or that the first feature and the second feature are in indirect contact through an intermediate medium. Furthermore, a first feature being located "above," "upper," and "upper surface" of a second feature may include the first feature being located immediately above or obliquely above the second feature, or simply indicate that the horizontal height of the first feature is higher than that of the second feature. A first feature being located "below," "lower," and "lower surface" of a second feature may include the first feature being located immediately below or obliquely below the second feature, or simply indicate that the horizontal height of the first feature is lower than that of the second feature.

[0045] Unless otherwise specified, the test temperature for each parameter mentioned in this disclosure is 25°C.

[0046] The solid-state battery cell mentioned in the embodiments of the present disclosure can independently implement charging and discharging functions and can be continuously used by activating the active material through a method of charging after discharge. The solid-state battery cell may be cylindrical, rectangular, or other shapes, and the embodiments of the present disclosure are not limited thereto. FIG. 1 is a solid-state battery cell (5) with a rectangular structure as an example.

[0047] The battery apparatus mentioned in the embodiments of the present disclosure may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include a plurality of solid-state battery cells connected in series, parallel, or hybridly via a busbar.

[0048] In some embodiments, the battery cell assembly is generally formed by arranging a plurality of solid-state battery cells.

[0049] For example, a battery cell assembly may be a battery module, and a battery module is a single independent module formed by arranging and fixing multiple solid-state battery cells. For example, a battery module may be formed by bundling multiple solid-state battery cells together using cable ties.

[0050] In some embodiments, the battery device may be a battery pack comprising a box and one or more battery cell assemblies accommodated in the box.

[0051] As an example, the battery cell assembly may be a battery module, and the battery cell assembly may be housed in a box so that the battery module is secured in the box.

[0052] As an example, a battery cell assembly can be housed in a box such that multiple solid-state battery cells are directly fixed to the box.

[0053] As an example, the box may include a first box and a second box. The first box and the second box interlock to form a sealed space inside the box to accommodate a battery cell assembly. Here, packaging means covering or closing, and may be sealed or non-sealed. The first box may be a cap or a bottom plate.

[0054] As an example, the box may include a cap, a frame, and a bottom plate. The cap and the bottom plate are each connected to the frame to form a sealed space inside the box, which accommodates a battery cell assembly.

[0055] In some embodiments, the box may be used as part of the chassis structure of the vehicle. For example, part of the box may be at least part of the floor of the vehicle, or part of the box may be at least part of the transverse beams and longitudinal beams of the vehicle.

[0056] The technical solutions described in the embodiments of the present disclosure are applicable to various electric devices using solid-state battery cells and battery devices, and the electric devices may be, for example, 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., but are not limited thereto. Solid-state battery cells and battery devices are used to store or supply electrical energy.

[0057] FIG. 2 is a schematic diagram of an electric device according to one example. The electric device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc.

[0058] The solid display cell provided in the embodiments of the present disclosure comprises an electrode assembly and an outer packaging for packaging the electrode assembly. The outer packaging may be a rigid case, such as, for example, a hard plastic case, an aluminum case, or a steel case. The outer packaging may be a soft pack, for example, a pouch soft pack. The material of the soft pack may be one or more of plastics, for example, an aluminum-plastic film, polypropylene, polybutylene terephthalate (PBT), and polybutylene succinate (PBS).

[0059] The positive electrode of a solid-state battery cell generally uses a high-potential transition metal oxide positive electrode active material. Interfacial side reactions inevitably occur due to the electrochemical potential difference between the transition metal oxide positive electrode active material and the sulfide solid electrolyte material, and the resulting interfacial byproducts increase the resistance of the solid-state battery cell, thereby hindering ion transport. Furthermore, oxygen released from the transition metal oxide positive electrode active material during the charging process oxidizes the sulfide solid electrolyte material, causing even more severe interfacial side reactions.

[0060] Currently, solid-state battery cells can achieve good cycle performance at room temperature by coating the transition metal oxide cathode active material with oxides, such as Li2NbO3 and Li2ZrO3, to reduce interfacial side reactions between the transition metal oxide cathode active material and the sulfide solid electrolyte material. However, when the solid-state battery cell is charged and discharged at high temperatures (e.g., >50°C), interfacial side reactions between the transition metal oxide cathode active material and the sulfide solid electrolyte material become more severe, and conventional oxide coating materials cannot effectively improve the capacity decay of the solid-state battery cell at high temperatures.

[0061] Accordingly, the present disclosure provides a positive electrode active material and a positive electrode sheet comprising the positive electrode active material, and when the positive electrode sheet is applied to a solid-state battery cell, the capacity decay rate at high temperatures of the solid-state battery cell can be reduced and high-temperature cycle performance improved.

[0062] The anode sheet of the present disclosure comprises an anode active material and a sulfide solid electrolyte material.

[0063] As illustrated in FIG. 3, the positive active material of the present disclosure comprises a matrix material (100), a cobalt-rich material (101) located on the surface of the matrix material (100), and a coating material (102) located on at least a portion of the surface of the cobalt-rich material (101). The matrix material (100) comprises a transition metal oxide, and the cobalt-rich material (101) comprises a transition metal oxide containing Co, wherein the molar content of the Co element in the cobalt-rich material is greater than the molar content of the Co element in the matrix material. The coating material (102) comprises an electrolyte salt material.

[0064] The positive electrode active material of the present disclosure comprises a cobalt-rich material located on the surface of a matrix material and a coating material located on at least a portion of the surface of the cobalt-rich material, wherein the matrix material comprises a transition metal oxide and the cobalt-rich material comprises a transition metal oxide containing Co, so the cobalt-rich material and the matrix material have better affinity and structural compatibility, thereby improving the overall structural stability of the positive electrode active material; furthermore, since the molar content of the Co element in the cobalt-rich material is greater than the molar content of the Co element in the matrix material, the cobalt-rich material located on the surface of the matrix material mitigates the decomposition of the sulfide solid electrolyte material by the matrix material, thereby improving the interfacial stability between the positive electrode active material and the sulfide solid electrolyte material.

[0065] The coating material includes an electrolyte salt material, and since the elastic modulus of the electrolyte salt material is much smaller than that of the matrix material, a coating over a larger area can be realized, thereby further reducing side reactions between the matrix material and the sulfide solid electrolyte material.

[0066] Accordingly, since the anode sheet of the present disclosure exhibits good high-temperature stability between the anode active material and the sulfide solid electrolyte material, applying the anode sheet to a solid battery cell can reduce the capacity decay rate at high temperatures of the solid battery cell and improve high-temperature cycle performance.

[0067] In some embodiments, the matrix material may include one or more of lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, and lithium-rich manganese-based materials.

[0068] In some embodiments, the cobalt-rich material may include one or more of cobalt-rich lithium nickel cobalt manganese oxide, cobalt-rich lithium nickel cobalt aluminum oxide, and cobalt-rich lithium-rich manganese-based materials.

[0069] In some embodiments, the matrix material may include lithium nickel cobalt manganese oxide, and the cobalt-rich material may include cobalt-rich lithium nickel cobalt manganese oxide.

[0070] In some embodiments, the matrix material may include lithium nickel cobalt aluminum oxide, and the cobalt-rich material may include cobalt-rich lithium nickel cobalt aluminum oxide.

[0071] In some embodiments, the matrix material may include a lithium-rich manganese-based material, and the cobalt-rich material may include a cobalt-rich lithium-rich manganese-based material.

[0072] In some embodiments, the cobalt-rich material may be located on 100% of the surface of the matrix material.

[0073] In some embodiments, there is no interface between the cobalt-rich material and the matrix material. Since there is no interface between the cobalt-rich material and the matrix material, the cobalt-rich material and the matrix material can have better affinity and structural compatibility, which can further improve the overall structural stability of the cathode active material.

[0074] In some embodiments, the matrix material may include a transition metal oxide containing Ni, and the cobalt-rich material may include a transition metal oxide containing Ni and Co, and the molar content of the Ni element in the cobalt-rich material may be smaller than the molar content of the Ni element in the matrix material.

[0075] The matrix material comprises a transition metal oxide containing Ni, and since the molar content of the Ni element in the matrix material is greater than the molar content of the Ni element in the cobalt-rich material, the cathode active material can be made to have a high specific capacity. Generally, side reactions between transition metal oxides containing a high content of Ni and sulfide solid electrolyte materials are more severe, which affects the capacity decay of solid-state battery cells at high temperatures. The present disclosure involves installing a cobalt-rich material and a coating material on the surface of the matrix material. The cobalt-rich material can mitigate the decomposition of the sulfide solid electrolyte material by the matrix material, thereby improving the interfacial stability between the cathode active material and the sulfide solid electrolyte material; the coating material comprises an electrolyte salt material, and since the elastic modulus of the electrolyte salt material is much lower than that of the matrix material, a coating over a larger area can be realized. Consequently, side reactions between the matrix material and the sulfide solid electrolyte material can be further reduced, and furthermore, the solid-state battery cell can be designed to achieve high energy density and good high-temperature cycle performance.

[0076] In some embodiments, the matrix material has the general formula Li a Ni b Co c M d O e A f The material may include, where 0.8≤a≤1.2, 0<b<1, 0<c<1, 0<d<1, 1≤e≤2, 0≤f≤1, M may include one or more elements among Mn, Al, Zr, Zn, Cu, Cr, Mg, Fe, V, Ti and B, and A may include one or more elements among N, F, S and Cl.

[0077] Optionally, 0.3≤b<1, 0.5≤b<1, 0.6≤b<1, 0.8≤b<1, 0.83≤b<1.

[0078] By increasing the content of Ni elements in the matrix material, the cathode active material can have a higher specific capacity, and the solid-state battery cell can be designed to accommodate both high energy density and good high-temperature cycle performance.

[0079] As an example, the matrix material is LiNi1 / 3Co1 / 3Mn1 / 3O2 (abbreviated as NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O2 (abbreviated as NCM523), LiNi0 . 5Co0 . 25 Mn0 . 25 O2 (abbreviated as NCM211), LiNi 0.6 Co 0.2 Mn 0.2 O2 (abbreviated as NCM622), LiNi0 . 8Co0 . 1Mn0 . 1O2 (abbreviated as NCM811), LiNi 0.83 Mn 0.08 Co 0.07 O2 (abbreviated as Ni83), LiNi0 . 90 Mn0 . 05 Co0 . 05 O2 (abbreviated as Ni90), LiNi 0.94 Mn 0.03 Co 0.03 O2 (abbreviated as Ni94), LiNi0 . 96 Co0 . 02 Mn0 . 02 O2 (abbreviated as Ni96) and LiNi 0.85 Co 0.1 Al 0.05 It may include one or more of O2, but is not limited thereto.

[0080] Optionally, the matrix material is LiNiO . 8Co0 .1Mn0 . 1O2 (abbreviated as NCM811), LiNi 0.83 Mn 0.08 Co 0.07 O2 (abbreviated as Ni83), LiNi0 . 90 Mn0 . 05 Co0 . 05 O2 (abbreviated as Ni90), LiNi 0.94 Mn 0.03 Co 0.03 O2 (abbreviated as Ni94), LiNi0 . 96 Co0 . 02 Mn0 . 02 O2 (abbreviated as Ni96), LiNi 0.85 Co 0.1 Al 0.05 It may include one or more of O2, but is not limited thereto.

[0081] Since solid-state battery cells involve the desorption and consumption of Li during the charging and discharging process, the molar content of Li differs when the solid-state battery cell is discharged in different states. In the examples relating to matrix materials in this disclosure, the molar content of Li is the initial state of the material, i.e., the state before supply, and the molar content of Li changes through charge-discharge cycles after applying the matrix material to the solid-state battery cell. In the examples relating to matrix materials in this disclosure, the molar content of O₂ is merely a theoretical state value, and since lattice oxygen emission causes the molar content of O₂ to change, the molar content of O₂ actually fluctuates.

[0082] In some embodiments, the cobalt-rich material has the general formula Li a1 Ni b1 Co c1 M 1 d1 O e1 A 1 f1The material may include 0, where 0.8≤a1≤1.2, 0<b1<1, 0<c1<1, 0<d1<1, 1≤e1≤2, 0≤f1≤1, M1 may include one or more elements among Mn, Al, Zr, Zn, Cu, Cr, Mg, Fe, V, Ti and B, and A1 may include one or more elements among N, F, S and Cl.

[0083] Optionally, c <c1이다.

[0084] Optionally, b > b1.

[0085] In some embodiments, the thickness range of the cobalt-rich material may be from 0.5 nm to 50 nm, for example, 0.5 nm, 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 8 nm, 10 nm, 12 nm, 14 nm, 16 nm, 18 nm, 20 nm, 22 nm, 24 nm, 26 nm, 28 nm, 30 nm, 32 nm, 34 nm, 36 nm, 38 nm, 40 nm, 42 nm, 44 nm, 46 nm, 48 nm, 50 nm, or a range combined with any of the above values.

[0086] When the thickness of the cobalt-rich material is within the above range, not only can the high-temperature stability of the cathode active material and the sulfide solid electrolyte material be improved, but the cathode active material can also have a higher specific capacity.

[0087] The thickness range of the cobalt-rich material can be obtained by combining EDS (Energy Dispersive Spectroscopy) elemental analysis with TEM (Transmission Electron Microscope) or SEM (Scanning Electron Microscope) surface scanning to obtain a cross-sectional image of the positive active material particle, and then by the Co elemental distribution of the cross-sectional image. During testing, a cross-section of the positive active material particle can be prepared using a cross-section grinder, and said cross-section passes through the core of the positive active material particle.

[0088] In some embodiments, the coating material may include a fluorine-containing electrolyte material.

[0089] Fluorine-containing electrolyte salt materials have better high-temperature and high-pressure stability and can decompose before sulfide solid electrolyte materials during the charging process to generate LiF, thereby reducing the decomposition of sulfide solid electrolyte materials, improving the high-temperature stability of cathode active materials and sulfide solid electrolyte materials, reducing the capacity decay rate at high temperatures of solid-state battery cells, and improving high-temperature cycle performance.

[0090] In some embodiments, the coating material may include one or more of Li2PO2F2, lithium difluoro(oxalate)borate (LiDFOB), lithium difluorodi(oxalate)phosphate (LiDFBOP), and lithium tetrafluoro(oxalate)phosphate (LiOTFP).

[0091] Within the above range, the coating material decomposes before the sulfide solid electrolyte material to generate LiF, which can then be coated onto the surface of the cobalt-rich material. This reduces the decomposition of the sulfide solid electrolyte material, improves the high-temperature stability of the cathode active material and the sulfide solid electrolyte material, and enables the cathode active material to possess high ionic electrical conductivity, thereby further enhancing the high-temperature cycle performance of the solid-state battery cell. Additionally, since the elastic modulus of this coating material is low, a larger coating area can be achieved, which further reduces side reactions between the matrix material and the sulfide solid electrolyte material.

[0092] In some embodiments, when the total mass of the positive active material is calculated as 100%, the mass fraction of the coating material may be 0.1% to 3%, for example, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3%, or a range combined with any of the above values.

[0093] Since the mass fraction of the coating material is within the above range, the positive active material can be made to have high ionic electrical conductivity and high specific capacity.

[0094] In some embodiments, the coating material may be located on 90% to 100% of the surface of the cobalt-rich material. Optionally, the coating material may be located on 100% of the surface of the cobalt-rich material.

[0095] Accordingly, side reactions between the matrix material and the sulfide solid electrolyte material can be further reduced, thereby reducing the capacity decay rate of the solid battery cell at high temperatures and improving high-temperature cycle performance.

[0096] In some embodiments, the positive electrode active material may further include metal particles located between the cobalt-rich material and the coating material, and the metal particles may include one or more of cobalt metal particles and cobalt oxide particles.

[0097] In some embodiments, the average particle size of the positive active material may be 3 μm to 10 μm, and may be, for example, a range of 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm or any combination of the above values.

[0098] In some embodiments, the positive active material may be a single crystal or a polycrystalline material.

[0099] In some embodiments, the sulfide solid electrolyte material may include one or more of Li6PS5X, LGPS-type sulfide solid electrolyte material and multi-component sulfide solid electrolyte material, and X includes one or more elements of F, Cl, Br and I.

[0100] Optionally, the LGPS-type sulfide solid electrolyte material is Li 10 ± δ5 Ge1 - g G g P2 - q Q q S 12 -w W w It may include, where 0≤δ5<1, 0≤g≤1, 0≤q≤2, 0≤w<1, G includes one or more elements among Si and Sn, Q includes Sb, and W includes one or more elements among O, Se, Te, Cl, Br, I and F.

[0101] Optionally, multicomponent sulfide solid electrolyte materials are Li2S-P2S5, Li2S-SiS2, Li2S-GeS2, and (100-uv)Li2S·uP2S5·vM m N n It may include one or more of, where, 0 <u<100, 0<v<100, 0<u+v<100, 0≤m<4, 0≤n<6이고, M은 Li, B, Ge, Si, Sn 및 Sb 중의 하나 이상의 원소를 포함하며, N은 S, Se, Te, O, Cl, Br, I 및 F 중의 하나 이상의 원소를 포함한다.

[0102] In some embodiments, as an example, the sulfide solid electrolyte material is Li6PS5Cl, Li6PS5Br, Li 10 GeP2S 12 , Li3PS4 and Li7P3S 11 It may include one or more of the following.

[0103] In some embodiments, the average particle size of the sulfide solid electrolyte material may be 1 nm to 20 μm, for example, 1 nm, 10 nm, 20 nm, 50 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 8 μm, 10 μm, 12 μm, 14 μm, 16 μm, 18 μm, 20 μm, or a combination of any of the above values. Optionally, the average particle size of the sulfide solid electrolyte material may be 50 nm to 5 μm.

[0104] In some embodiments, the mass ratio of the cathode active material to the sulfide solid electrolyte material may be from 99:1 to 70:30, for example, 99:1, 98:2, 97:3, 96:4, 95:5, 94:6, 93:7, 92:8, 91:9, 90:10, 89:11, 88:12, 87:13, 86:14, 85:15, 84:16, 83:17, 82:18, 81:19, 80:20, 79:21, 78:22, 77:23, 76:24, 75:25, 74:26, 73:27, 72:28, 71:29, 70:30, or a range of any combination of the above values. there is.

[0105] When the mass ratio of the positive electrode active material and the sulfide solid electrolyte material is within the above range, the solid-state battery cell can be made to have high energy density, high ion transfer characteristics, and good cycle performance.

[0106] Optionally, the mass ratio of the positive active material and the sulfide solid electrolyte material may be 95:5 to 70:30, 90:10 to 70:30, 85:15 to 70:30, 95:5 to 72:28, 90:10 to 72:28, and 85:15 to 72:28.

[0107] In some embodiments, the anode sheet may further comprise an anode binder, and the anode binder is polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, fluorinated acrylate resin, water-soluble unsaturated resin SR-1B, methyl vinyl silicone rubber, nitrile butadiene rubber (NBR), hydrogenated nitrile butadiene rubber (HNBR), styrene-butadiene rubber (SBR), thermoplastic styrene-butadiene rubber (SBS), polyisoprene, polybutadiene (BR), ethyl cellulose, polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), It may include one or more of sodium alginate (SA), polymethacrylic acid (PMAA), carboxymethyl chitosan (CMCS), fluororubber, and acrylate rubber, but is not limited thereto.

[0108] In some embodiments, the anode sheet may further comprise an anode conductive agent, and the anode conductive agent may comprise one or more of conductive graphite (e.g., KS-6, SFG-6), superconducting carbon, acetylene black, carbon black (e.g., SP), cotinine black (e.g., ECP), carbon dots, carbon nanotubes, graphene, carbon nanofibers, and vapor-grown carbon fibers (VGCF), but is not limited thereto.

[0109] The positive sheet may or may not include a positive current collector.

[0110] In some embodiments, the anode sheet may include an anode current collector and an anode film layer located on at least one surface of the anode current collector, and the anode film layer includes an anode active material and a sulfide solid electrolyte material.

[0111] The positive current collector has two opposing surfaces in its thickness direction, and the positive film layer is installed on either one or both of the two opposing surfaces of the positive current collector.

[0112] In some embodiments, the anode film layer may further comprise an anode binder, and the anode binder is polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, fluorinated acrylate resin, water-soluble unsaturated resin SR-1B, methyl vinyl silicone rubber, nitrile butadiene rubber (NBR), hydrogenated nitrile butadiene rubber (HNBR), styrene-butadiene rubber (SBR), thermoplastic styrene-butadiene rubber (SBS), polyisoprene, polybutadiene (BR), ethyl cellulose, polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), It may include one or more of sodium alginate (SA), polymethacrylic acid (PMAA), carboxymethyl chitosan (CMCS), fluororubber, and acrylate rubber, but is not limited thereto.

[0113] In some embodiments, the anode film layer may further comprise an anode conductive agent, and the anode conductive agent may comprise one or more of conductive graphite (e.g., KS-6, SFG-6), superconducting carbon, acetylene black, carbon black (e.g., SP), cotinine black (e.g., ECP), carbon dots, carbon nanotubes, graphene, carbon nanofibers, and vapor-grown carbon fibers (VGCF), but is not limited thereto.

[0114] In some embodiments, the positive current collector may be a metal foil sheet or a composite current collector. For example, as the metal foil sheet, stainless steel foil, carbon-coated aluminum foil, aluminum foil, nickel foil, or titanium foil may be used. The composite current collector may include a polymer material base layer and a metal material layer formed on at least one surface of the polymer material base layer. For example, the metal material may include one or more of aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, but is not limited thereto. For example, the polymer material base layer may include one or more of polypropylene, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene, but is not limited thereto.

[0115] The anode sheet can be manufactured through a dry process or a wet process.

[0116] The present disclosure further provides a method for manufacturing a positive active material capable of manufacturing the above positive active material.

[0117] A method for manufacturing a positive electrode active material comprises the steps of: providing a matrix material comprising a transition metal oxide, a cobalt raw material, and a coating material comprising an electrolyte salt material; mixing the matrix material and the cobalt raw material and performing a first heat treatment in an oxygen-containing atmosphere to obtain an intermediate material; and mixing the obtained intermediate material and the coating material and performing a second heat treatment in an oxygen-containing atmosphere to obtain a positive electrode active material. Herein, the positive electrode active material comprises a matrix material, a cobalt-rich material located on the surface of the matrix material, and a coating material located on at least a portion of the surface of the cobalt-rich material, wherein the matrix material comprises a transition metal oxide, the cobalt-rich material comprises a transition metal oxide containing Co, the molar content of the Co element in the cobalt-rich material is greater than the molar content of the Co element in the matrix material, and the coating material comprises an electrolyte salt material.

[0118] By mixing a matrix material and a cobalt raw material and performing a primary heat treatment in an oxygen-containing atmosphere, a cobalt-rich material can be formed in situ through the diffusion of Co elements from the surface of the matrix material. Since there is no interface between the formed cobalt-rich material and the matrix material, and the cobalt-rich material and the matrix material can have better affinity and structural compatibility, the overall structural stability of the cathode active material can be improved. In addition, an in situ coating of the cobalt-rich material can be realized on the entire surface of the matrix material through the diffusion of Co elements from the surface of the matrix material.

[0119] The coating material includes an electrolyte salt material, and since the elastic modulus of the electrolyte salt material is much smaller than that of the matrix material, a coating over a larger area can be realized, thereby further reducing side reactions between the matrix material and the sulfide solid electrolyte material.

[0120] Accordingly, since the positive active material produced by the manufacturing method of the present disclosure has better high-temperature stability, the high-temperature stability between the positive active material and the sulfide solid electrolyte material is good, so when applied to a solid-state battery cell, the capacity decay rate at high temperatures of the solid-state battery cell can be reduced and high-temperature cycle performance can be improved.

[0121] In some embodiments, the primary heat treatment temperature may be 500°C to 800°C, for example, 500°C, 520°C, 540°C, 560°C, 580°C, 600°C, 620°C, 640°C, 660°C, 680°C, 700°C, 720°C, 740°C, 760°C, 780°C, 800°C, or a range combined with any of the above values.

[0122] When the first heat treatment temperature is within the above range, Co elements can be more preferably diffused onto the surface of the matrix material, and an in-situ coating of the cobalt-rich material can be achieved on the entire surface of the matrix material.

[0123] In some embodiments, the time of the first heat treatment may be 0.5h to 10h, and may be, for example, a range of 0.5h, 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h or any combination of the above values.

[0124] When the time of the first heat treatment is within the above range, Co elements can be more preferably diffused onto the surface of the matrix material, and an in-situ coating of the cobalt-rich material can be achieved on the entire surface of the matrix material.

[0125] In some embodiments, the temperature of the secondary heat treatment may be 300°C to 400°C, for example, 300°C, 310°C, 320°C, 330°C, 340°C, 350°C, 360°C, 370°C, 380°C, 390°C, 400°C, or a range combined with any of the above values.

[0126] In some embodiments, the time of the second heat treatment may be 0.5h to 5h, for example, a range of 0.5h, 1h, 2h, 3h, 4h, 5h or any combination of the above values.

[0127] In some embodiments, the volume fraction of oxygen in the oxygen-containing atmosphere may be 50% to 100%. For example, the oxygen-containing atmosphere may be oxygen or a mixture of oxygen and an inert gas. The inert gas may include one or more of nitrogen, argon, and helium, but is not limited thereto.

[0128] In some embodiments, the cobalt raw material may include one or more of cobalt hydroxide and cobalt oxide.

[0129] In some embodiments, when the total mass of the matrix material and the cobalt raw material is calculated as 100%, the mass fraction of the cobalt raw material may be 0.1% to 3%, for example, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3% or a range combined with any of the above values.

[0130] By controlling the amount of cobalt raw material used, the thickness range of the cobalt-rich material can be controlled, and cobalt metal particles and / or cobalt oxide particles can be formed on the surface of a transition metal oxide containing Co.

[0131] In some embodiments, the mixing method of the matrix material and the cobalt raw material may be dry mixing or wet mixing.

[0132] In some embodiments, the mixing method of the intermediate material and the coating material may be dry mixing or wet mixing.

[0133] The present disclosure further provides a solid-state battery cell comprising a negative electrode sheet, a solid electrolyte membrane, and an anode sheet according to the present disclosure, wherein the solid electrolyte membrane is positioned between the negative electrode sheet and the anode sheet.

[0134] [Cathode Sheet]

[0135] The cathode sheet can be manufactured through a dry process or a wet process.

[0136] In some embodiments, the cathode sheet may include one or more of lithium, lithium alloy, natural graphite, artificial graphite, mesocarbon micro beads, soft carbon, hard carbon, silicon-based material, tin-based material, lithium titanate, and metal oxide.

[0137] Optionally, the mass fraction of the lithium element in the lithium alloy can be 90% or more.

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

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

[0140] Optionally, silicon-based materials may include one or more of metallic silicon, silicon oxide, silicon-carbon composite materials, silicon-nitrogen composite materials, and silicon alloys, but are not limited thereto.

[0141] Optionally, tin-based materials may include one or more of metallic tin, tin oxide, and tin alloy materials, but are not limited thereto.

[0142] Optionally, the metal oxide may include one or more of TiO2, MoO2, In2O3, Al2O3, Cu2O, VO2, Ga2O3, Sb2O5 and Bi2O5, but is not limited thereto.

[0143] In some embodiments, the cathode sheet may further comprise a cathode binder, and the cathode binder may comprise, but is not limited to, one or more of styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, polyacrylic acid, polymethacrylic acid, sodium polyacrylate, polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), carboxymethyl chitosan (CMCS), methyl vinyl silicone rubber, nitrile-butadiene rubber (NBR), hydrogenated nitrile-butadiene rubber (HNBR), thermoplastic styrene-butadiene rubber (SBS), polyisoprene rubber, polybutadiene rubber (BR), ethyl cellulose, fluororubber, and acrylate rubber.

[0144] In some embodiments, the cathode sheet may or may not include a cathode conductive agent.

[0145] Optionally, the cathode conductive agent may include, but is not limited to, one or more of conductive graphite (e.g., KS-6, SFG-6), superconducting carbon, acetylene black, carbon black (e.g., SP), cotinine black (e.g., ECP), carbon dots, carbon nanotubes, graphene, carbon nanofibers, and vapor-grown carbon fibers (VGCF).

[0146] In some embodiments, the cathode sheet may or may not further comprise a solid electrolyte material. Optionally, the solid electrolyte material may comprise one or more of a sulfide solid electrolyte material, a halide solid electrolyte material, and an oxide solid electrolyte material, but is not limited thereto.

[0147] Regarding the types of sulfide solid electrolyte materials, you may refer to the sulfide solid electrolyte materials in the anode sheets described above, and further details will not be provided here.

[0148] Optionally, the halogenated solid electrolyte material may include one or more of Li3YCl6, Li3YBr6, Li3ErCl6, Li3InCl6, and Li3InBr6.

[0149] Optionally, the oxide solid electrolyte material may include one or more of an oxide solid electrolyte material having a perovskite structure, an oxide solid electrolyte material having a garnet structure, an oxide solid electrolyte material having a NASICON structure, and an oxide solid electrolyte material having a LISICON structure.

[0150] In some embodiments, the cathode sheet may be a metal sheet, such as a lithium sheet or a lithium alloy sheet.

[0151] The cathode sheet may or may not include a cathode current collector.

[0152] In some embodiments, the cathode sheet may comprise a cathode current collector and a lithium-based metal layer located on at least one surface of the cathode current collector. The cathode current collector has two opposing surfaces in its thickness direction, and the lithium-based metal layer is installed on either one or both of the two opposing surfaces of the cathode current collector.

[0153] In some embodiments, the lithium-based metal layer may be metallic lithium or a lithium alloy.

[0154] In some embodiments, the cathode sheet may comprise a cathode current collector and a cathode film layer located on at least one surface of the cathode current collector, and the cathode film layer comprises a cathode active material. The cathode current collector has two opposing surfaces in its thickness direction, and the cathode film layer is installed on either one or both of the two opposing surfaces of the cathode current collector.

[0155] In some embodiments, the negative electrode active material may include one or more of natural graphite, artificial graphite, mesocarbon micro beads, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, and metal oxides, but is not limited thereto.

[0156] In some embodiments, the cathode film layer may further comprise a cathode binder, and the cathode binder may comprise, but is not limited to, one or more of styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, polyacrylic acid, polymethacrylic acid, sodium polyacrylate, polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), carboxymethyl chitosan (CMCS), methyl vinyl silicone rubber, nitrile-butadiene rubber (NBR), hydrogenated nitrile-butadiene rubber (HNBR), thermoplastic styrene-butadiene rubber (SBS), polyisoprene rubber, polybutadiene rubber (BR), ethyl cellulose, fluororubber, and acrylate rubber.

[0157] In some embodiments, the cathode film layer may or may not include a cathode conductive agent.

[0158] Optionally, the cathode conductive agent may include, but is not limited to, one or more of conductive graphite (e.g., KS-6, SFG-6), superconducting carbon, acetylene black, carbon black (e.g., SP), cotinine black (e.g., ECP), carbon dots, carbon nanotubes, graphene, carbon nanofibers, and vapor-grown carbon fibers (VGCF).

[0159] In some embodiments, the cathode film layer may or may not further comprise a solid electrolyte material. Optionally, the solid electrolyte material may comprise one or more of a sulfide solid electrolyte material, a halide solid electrolyte material, and an oxide solid electrolyte material, but is not limited thereto.

[0160] Regarding the types of sulfide solid electrolyte materials, you may refer to the sulfide solid electrolyte materials in the anode sheets described above, and they will not be explained further here.

[0161] Optionally, the halogenated solid electrolyte material may include one or more of Li3YCl6, Li3YBr6, Li3ErCl6, Li3InCl6, and Li3InBr6.

[0162] Optionally, the oxide solid electrolyte material may include one or more of an oxide solid electrolyte material having a perovskite structure, an oxide solid electrolyte material having a garnet structure, an oxide solid electrolyte material having a NASICON structure, and an oxide solid electrolyte material having a LISICON structure.

[0163] In some embodiments, the negative current collector may be a metal foil sheet, a three-dimensional porous current collector, or a composite current collector. For example, copper foil, copper alloy foil, nickel foil, nickel alloy foil, aluminum foil, or aluminum alloy foil may be used as the metal foil sheet. For example, copper mesh, nickel mesh, aluminum mesh, copper foam, nickel foam, and aluminum foam may be used as the three-dimensional porous current collector. The composite current collector may include a polymer material base layer and a metal material layer formed on at least one surface of the polymer material base layer. For example, the metal material may include one or more of copper, copper alloy, aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, but is not limited thereto. For example, the polymer material base layer may include one or more of polypropylene, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene, and polyethylene, but is not limited thereto.

[0164] [Solid Electrolyte Membrane]

[0165] Solid electrolyte membranes can be manufactured through a dry process or a wet process.

[0166] In some embodiments, the solid electrolyte membrane may comprise a solid electrolyte material. Optionally, the solid electrolyte material may comprise one or more of a sulfide solid electrolyte material, a halide solid electrolyte material, and an oxide solid electrolyte material, but is not limited thereto.

[0167] Regarding the types of sulfide solid electrolyte materials, you may refer to the sulfide solid electrolyte materials in the anode sheets described above, and they will not be explained further here.

[0168] Optionally, the halogenated solid electrolyte material may include one or more of Li3YCl6, Li3YBr6, Li3ErCl6, Li3InCl6, and Li3InBr6.

[0169] Optionally, the oxide solid electrolyte material may include one or more of an oxide solid electrolyte material having a perovskite structure, an oxide solid electrolyte material having a garnet structure, an oxide solid electrolyte material having a NASICON structure, and an oxide solid electrolyte material having a LISICON structure.

[0170] In some embodiments, the solid electrolyte membrane may further include a binder. Optionally, the binder is polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, fluorinated acrylate resin, water-soluble unsaturated resin SR-1B, methyl vinyl silicone rubber, nitrile butadiene rubber (NBR), hydrogenated nitrile butadiene rubber (HNBR), styrene-butadiene rubber (SBR), thermoplastic styrene-butadiene rubber (SBS), polyisoprene, polybutadiene (BR), ethyl cellulose, polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), It may include one or more of carboxymethyl chitosan (CMCS), fluororubber, and acrylate rubber, but is not limited thereto.

[0171] A method for manufacturing a solid-state battery cell is known, and, for example, a method for assembling a solid-state battery cell may include, but is not limited to, button-type batteries, mold-type batteries, rigid-case batteries, soft-pack batteries, etc.

[0172] Examples

[0173] The following examples are intended to explain the contents of the disclosure more specifically; however, these examples are merely descriptive, and those skilled in the art may make various modifications and variations within the scope of the contents of the disclosure. Unless otherwise specified, all fractions, percentages, and ratios described in the examples below are based on mass, all reagents used in the examples can be purchased or synthesized by general methods and can be used directly without further processing, and all equipment used in the examples can be purchased.

[0174] Examples 1

[0175] Preparation of positive electrode active material

[0176] LiNiO with a mass ratio of 99.5:0.5 . 8Co0 . 1Mn0 . 1O2 (abbreviated as NCM811) powder and Co(OH)2 powder were taken and uniformly mixed using a dry coating device; the uniformly mixed material was heat-treated at 600°C for 1 hour in an oxygen atmosphere to obtain an intermediate material; the intermediate material powder and LiPO2F2 (abbreviated as LPF) powder were taken in a mass ratio of 99:1 and uniformly mixed using a dry coating device; the uniformly mixed material was heat-treated at 320°C for 1 hour in an oxygen atmosphere to obtain a positive active material. The positive active material comprises NCM811 as a matrix material, a cobalt-rich material located on the surface of NCM811 (i.e., Co-doped cobalt-rich NCM811), and LiPO2F2 as a coating material located on the surface of the cobalt-rich material, and the thickness range of the cobalt-rich material is 0.5 nm to 50 nm.

[0177] Manufacturing of anode sheets

[0178] The anode active material prepared above, Li6PS5Cl as a sulfide solid electrolyte material, vapor-grown carbon fiber (VGCF) as an anode conductive agent, and polytetrafluoroethylene (PTFE) as an anode binder were uniformly mixed in a dual-planetary mixer in a solid mass ratio of 85:12:2:1. Then, the uniformly mixed material was heated, pressurized, and kneaded in an internal mixer to form a mass, and then hot-roll pressed at 80°C to form a self-supporting electrode sheet. Finally, the electrode sheet was hot-roll laminated onto an aluminum foil as an anode current collector to obtain an anode sheet. The thickness of the anode sheet is 100 μm.

[0179] Manufacturing of solid-state battery cells

[0180] 100 mg of Li6PS5Cl, a sulfide solid electrolyte material, was taken, added to a battery mold, and pressurized to obtain an electrolyte sheet, then an anode sheet was added to one side of the electrolyte sheet and an InLi alloy was added to the other side to form a cathode, and a solid battery cell was obtained by pressing at 500 MPa for 5 min.

[0181] Examples 2

[0182] Except for the following differences, the method of manufacturing the solid-state battery cell is the same as in Example 1.

[0183] Preparation of positive electrode active material

[0184] LiNiO at a mass ratio of 98.5:1.5 . 8Co0 . 1Mn0 .1O2 (abbreviated as NCM811) powder and Co(OH)2 powder were taken and uniformly mixed using a dry coating device; the uniformly mixed material was heat-treated at 600°C for 1 hour in an oxygen atmosphere to obtain an intermediate material; the intermediate material powder and LiPO2F2 (abbreviated as LPF) powder were taken in a mass ratio of 99:1 and uniformly mixed using a dry coating device; the uniformly mixed material was heat-treated at 320°C for 1 hour in an oxygen atmosphere to obtain a positive active material. The positive active material comprises NCM811 as a matrix material, a cobalt-rich material located on the surface of NCM811 (i.e., Co-doped cobalt-rich NCM811), and LiPO2F2 as a coating material located on the surface of the cobalt-rich material, and the thickness range of the cobalt-rich material is 0.5 nm to 50 nm.

[0185] Examples 3

[0186] Except for the following differences, the method of manufacturing the solid-state battery cell is the same as in Example 1.

[0187] Preparation of positive electrode active material

[0188] LiNiO with a mass ratio of 97:3 . 8Co0 . 1Mn0 .1O2 (abbreviated as NCM811) powder and Co(OH)2 powder were taken and uniformly mixed using a dry coating device; the uniformly mixed material was heat-treated at 600°C for 1 hour in an oxygen atmosphere to obtain an intermediate material; the intermediate material powder and LiPO2F2 (abbreviated as LPF) powder were taken in a mass ratio of 99:1 and uniformly mixed using a dry coating device; the uniformly mixed material was heat-treated at 320°C for 1 hour in an oxygen atmosphere to obtain a positive active material. The positive active material comprises NCM811 as a matrix material, a cobalt-rich material located on the surface of NCM811 (i.e., Co-doped cobalt-rich NCM811), and LiPO2F2 as a coating material located on the surface of the cobalt-rich material, and the thickness range of the cobalt-rich material is 0.5 nm to 50 nm.

[0189] Examples 4

[0190] Except for the following differences, the method of manufacturing the solid-state battery cell is the same as in Example 1.

[0191] Preparation of positive electrode active material

[0192] LiNiO with a mass ratio of 99.5:0.5 . 8Co0 . 1Mn0 .1O2 (abbreviated as NCM811) powder and Co(OH)2 powder were taken and uniformly mixed using a dry coating device; the uniformly mixed material was heat-treated at 600°C for 1 hour in an oxygen atmosphere to obtain an intermediate material; the intermediate material powder and LiPO2F2 (abbreviated as LPF) powder were taken in a mass ratio of 97:3 and uniformly mixed using a dry coating device; the uniformly mixed material was heat-treated at 320°C for 1 hour in an oxygen atmosphere to obtain a positive active material. The positive active material comprises NCM811 as a matrix material, a cobalt-rich material located on the surface of NCM811 (i.e., Co-doped cobalt-rich NCM811), and LiPO2F2 as a coating material located on the surface of the cobalt-rich material, and the thickness range of the cobalt-rich material is 0.5 nm to 50 nm.

[0193] Examples 5

[0194] Except for the following differences, the method of manufacturing the solid-state battery cell is the same as in Example 1.

[0195] Preparation of positive electrode active material

[0196] LiNiO with a mass ratio of 99.5:0.5 . 8Co0 . 1Mn0 .1O2 (abbreviated as NCM811) powder and Co(OH)2 powder were taken and uniformly mixed using a dry coating device; the uniformly mixed material was heat-treated at 600°C for 1 hour in an oxygen atmosphere to obtain an intermediate material; the intermediate material powder and LiPO2F2 (abbreviated as LPF) powder were taken in a mass ratio of 99.9:0.1 and uniformly mixed using a dry coating device; the uniformly mixed material was heat-treated at 320°C for 1 hour in an oxygen atmosphere to obtain a positive active material. The positive active material comprises NCM811 as a matrix material, a cobalt-rich material located on the surface of NCM811 (i.e., Co-doped cobalt-rich NCM811), and LiPO2F2 as a coating material located on the surface of the cobalt-rich material, and the thickness range of the cobalt-rich material is 0.5 nm to 50 nm.

[0197] Examples 6

[0198] Except for the following differences, the method of manufacturing the solid-state battery cell is the same as in Example 1.

[0199] Preparation of positive electrode active material

[0200] LiNiO with a mass ratio of 99.5:0.5 . 8Co0 . 1Mn0 .1O2 (abbreviated as NCM811) powder and Co(OH)2 powder were taken and uniformly mixed using a dry coating device; the uniformly mixed material was heat-treated at 600°C for 1 hour in an oxygen atmosphere to obtain an intermediate material; the intermediate material powder and lithium difluoro(oxalate)borate (abbreviated as LiDFOB) powder were taken in a mass ratio of 99:1 and uniformly mixed using a dry coating device; the uniformly mixed material was heat-treated at 320°C for 1 hour in an oxygen atmosphere to obtain a positive active material. The positive active material comprises NCM811 as a matrix material, a cobalt-rich material located on the surface of NCM811 (i.e., Co-doped cobalt-rich NCM811), and LiDFOB as a coating material located on the surface of the cobalt-rich material, and the thickness range of the cobalt-rich material is 0.5 nm to 50 nm.

[0201] Comparative example 1

[0202] Manufacturing of anode sheets

[0203] LiNiO, the positive active material . 8Co0 . 1Mn0 . 1O2 (abbreviated as NCM811), Li6PS5Cl as a sulfide solid electrolyte material, vapor-grown carbon fiber (VGCF) as an anode conductive agent, and polytetrafluoroethylene (PTFE) as an anode binder were uniformly mixed in a dual-planetary mixer in a solid mass ratio of 85:12:2:1, and then the uniformly mixed material was heated, pressurized, and kneaded in an internal mixer to form a mass, and then hot-roll pressed at 80°C to form a self-supporting electrode sheet, and finally, the electrode sheet was hot-roll laminated onto an aluminum foil as an anode current collector to obtain an anode sheet. The thickness of the anode sheet is 100 μm.

[0204] Manufacturing of solid-state battery cells

[0205] 100 mg of Li6PS5Cl, a sulfide solid electrolyte material, was taken, added to a battery mold, and pressurized to obtain an electrolyte sheet, then an anode sheet was added to one side of the electrolyte sheet and an InLi alloy was added to the other side to form a cathode, and a solid battery cell was obtained by pressing at 500 MPa for 5 min.

[0206] Comparative example 2

[0207] Except for the following differences, the method of manufacturing the solid-state battery cell is the same as in Example 1.

[0208] Preparation of positive electrode active material

[0209] LiNiO with a mass ratio of 99.5:0.5 . 8Co0 . 1Mn0 . 1O2 (abbreviated as NCM811) powder and Co(OH)2 powder were taken and uniformly mixed using a dry coating device; the uniformly mixed material was heat-treated at 600°C for 1 hour in an oxygen atmosphere to obtain a positive electrode active material.

[0210] Comparative example 3

[0211] Except for the following differences, the method of manufacturing the solid-state battery cell is the same as in Example 1.

[0212] Preparation of positive electrode active material

[0213] LiNiO with a mass ratio of 99.5:0.5 . 8Co0 . 1Mn0 . 1O2 (abbreviated as NCM811) powder and Li2ZrO3 powder were taken and uniformly mixed using a dry coating device; the uniformly mixed material was heat-treated at 400°C for 1 hour in an oxygen atmosphere to obtain a positive electrode active material.

[0214] Performance test

[0215] (1) First-cycle Coulomb efficiency test

[0216] At 60°C, the solid-state battery cell was charged to 4.3V (Li+ / Li) at a current density of 0.1C, stopped for 10 min, and then discharged to 2.8V (Li+ / Li) at a current density of 0.1C to obtain the first cycle charge specific capacity and the first cycle discharge specific capacity.

[0217] 1st cycle Coulomb efficiency (%) = 1st cycle discharge capacity / 1st cycle charge capacity × 100%.

[0218] (2) Cycle performance test

[0219] At 60°C, the solid-state battery cell is charged to 4.3V (vs. Li+ / Li) at a current density of 0.1C and stopped for 10 minutes, then discharged to 2.8V (vs. Li+ / Li) at a current density of 0.1C to perform the charge-discharge cycle three times; the solid-state battery cell is charged to 4.3V (vs. Li+ / Li) at a current density of 0.33C and stopped for 10 minutes, then discharged to 2.8V (vs. Li+ / Li) at a current density of 0.33C, recording the discharge capacity at this time as C1, and the solid-state battery cell is charged and discharged 200 times at a current density of 0.33C, recording the discharge capacity at this time as C2.

[0220] Capacity retention rate of a solid-state battery cell at 200 cycles = C2 / C1 × 100%.

[0221] turn 0.1C Primary Discharge Capacity (mAh / g) 1st Coulombic Efficiency (%) 0.33C discharge capacity C1 (mAh / g) Capacity retention rate (%) at 200 cycles at 60°C Example 1 210.4 92.5 200.2 94.6 Example 2 208.6 92.7 198.3 95.1 Example 3 206.6 93.1 196.5 95.5 Example 4 207.5 93.5 196.8 96.2 Example 5 212.6 91.3 201.5 92.8 Example 6 211.5 92.4 201.4 94.5 Comparative Example 1 190.2 83.5 176.8 20.3 Comparative Example 2 200.5 86.4 188.5 35.4 Comparative Example 3 206.4 89.7 194.2 38.7

[0222] Based on the above test results, it can be seen that the anode sheet of the present disclosure exhibits good high-temperature stability between the anode active material and the sulfide solid electrolyte material, thereby reducing the capacity decay rate at high temperatures of the solid-state battery cell and improving high-temperature cycle performance.

[0223] It should be noted that the present disclosure is not limited to the embodiments described above. The embodiments described above are merely examples, and all embodiments having substantially the same configuration as the technical concept and producing the same effect within the scope of the technical plan of the present disclosure are included within the technical scope of the present disclosure. Furthermore, other forms formed by implementing various modifications that a person skilled in the art may conceive of regarding the embodiments without departing from the spirit of the present disclosure, and other forms formed by combining some components of the embodiments, are also included within the scope of the present disclosure.

Claims

Claim 1 A positive electrode sheet comprising: a positive electrode active material and a sulfide solid electrolyte material, wherein the positive electrode active material comprises a matrix material, a cobalt-rich material located on the surface of the matrix material, and a coating material located on at least a portion of the surface of the cobalt-rich material; wherein the matrix material comprises a transition metal oxide, the cobalt-rich material comprises a transition metal oxide containing Co, and the molar content of the Co element in the cobalt-rich material is greater than the molar content of the Co element in the matrix material; and wherein the coating material comprises an electrolyte salt material. Claim 2 In claim 1, the anode sheet comprising a coating material containing a fluorine-containing electrolyte material. Claim 3 An anode sheet according to any one of claims 1 to 2, wherein the coating material comprises one or more of Li2PO2F2, lithium difluoro(oxalate)borate, lithium difluorodi(oxalate)phosphate, and lithium tetrafluoro(oxalate)phosphate. Claim 4 An anode sheet according to any one of claims 1 to 3, wherein the mass fraction of the coating material is 0.1% to 3% when the total mass of the anode active material is calculated as 100%. Claim 5 An anode sheet according to any one of claims 1 to 4, wherein the coating material is located on 90% to 100% of the surface of the cobalt-rich material. Claim 6 An anode sheet according to any one of claims 1 to 5, wherein the thickness range of the cobalt-rich material is 0.5 nm to 50 nm. Claim 7 An anode sheet according to any one of claims 1 to 6, wherein the matrix material comprises one or more of lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, and lithium-rich manganese-based material; and / or, the cobalt-rich material comprises one or more of cobalt-rich lithium nickel cobalt manganese oxide, cobalt-rich lithium nickel cobalt aluminum oxide, and cobalt-rich lithium-rich manganese-based material. Claim 8 An anode sheet according to any one of claims 1 to 7, wherein the matrix material comprises a transition metal oxide containing Ni, the cobalt-rich material comprises a transition metal oxide containing Ni and Co, and the molar content of the Ni element in the cobalt-rich material is smaller than the molar content of the Ni element in the matrix material. Claim 9 An anode sheet according to any one of claims 1 to 8, wherein the cobalt-rich material is located on 100% of the surface of the matrix material; and / or, there is no interface between the cobalt-rich material and the matrix material. Claim 10 An anode sheet according to any one of claims 1 to 9, wherein the anode active material further comprises metal particles located between the cobalt-rich material and the coating material, and the metal particles comprise one or more of cobalt metal particles and cobalt oxide particles. Claim 11 An anode sheet according to any one of claims 1 to 10, wherein the average particle size of the anode active material is 3 μm to 10 μm; and / or, the average particle size of the sulfide solid electrolyte material is 1 nm to 20 μm; and / or, the mass ratio of the anode active material to the sulfide solid electrolyte material is 99:1 to 70:

30. Claim 12 An anode sheet according to any one of claims 1 to 11, wherein the anode sheet further comprises an anode conductive agent and / or an anode binder. Claim 13 An anode sheet according to any one of claims 1 to 12, wherein the anode sheet further comprises an anode current collector, and the anode active material and the sulfide solid electrolyte material are located on at least one surface of the anode current collector. Claim 14 A solid battery cell comprising a cathode sheet, a solid electrolyte membrane, and an anode sheet according to any one of claims 1 to 13, wherein the solid electrolyte membrane is located between the cathode sheet and the anode sheet. Claim 15 In claim 14, the cathode sheet comprises one or more of lithium, lithium alloy, natural graphite, artificial graphite, mesocarbon microbeads, soft carbon, hard carbon, silicon-based material, tin-based material, lithium titanate, and metal oxide; and / or, the solid electrolyte membrane comprises one or more of sulfide solid electrolyte material, halide solid electrolyte material, and oxide solid electrolyte material, a solid battery cell. Claim 16 A battery device comprising a solid-state battery cell according to any one of claims 14 to 15. Claim 17 An electric device comprising a solid-state battery cell according to any one of claims 14 to 15 or a battery device according to claim 16. Claim 18 A positive electrode active material, wherein the positive electrode active material comprises a matrix material, a cobalt-rich material located on the surface of the matrix material, and a coating material located on at least a portion of the surface of the cobalt-rich material; wherein the matrix material comprises a transition metal oxide, the cobalt-rich material comprises a transition metal oxide containing Co, and the molar content of the Co element in the cobalt-rich material is greater than the molar content of the Co element in the matrix material; and the coating material comprises an electrolyte salt material. Claim 19 A method for manufacturing an anode active material comprising: a step of providing a coating material comprising a matrix material including a transition metal oxide, a cobalt raw material, and an electrolyte salt material; a step of mixing the matrix material and the cobalt raw material and performing a first heat treatment in an oxygen-containing atmosphere to obtain an intermediate material; a step of mixing the obtained intermediate material and the coating material and performing a second heat treatment in an oxygen-containing atmosphere to obtain an anode active material; wherein the anode active material comprises a matrix material, a cobalt-rich material located on the surface of the matrix material, and a coating material located on at least a portion of the surface of the cobalt-rich material, wherein the matrix material comprises a transition metal oxide, the cobalt-rich material comprises a transition metal oxide containing Co, the molar content of the Co element in the cobalt-rich material is greater than the molar content of the Co element in the matrix material, and the coating material comprises an electrolyte salt material. Claim 20 A method of manufacturing according to claim 19, wherein the temperature of the first heat treatment is 500℃ to 800℃; and / or, the time of the first heat treatment is 0.5h to 10h; and / or, the temperature of the second heat treatment is 300℃ to 400℃; and / or, the time of the second heat treatment is 0.5h to 5h; and / or, the cobalt raw material comprises one or more of cobalt hydroxide and cobalt oxide.

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