Positive electrode active layer composition, positive electrode active coated particle, positive electrode film, solid-state battery, electric device, and use

Abstract

The present application relates to a positive electrode active layer composition, a positive electrode active coated particle, a positive electrode film, a solid-state battery, an electric device, and a use. The positive electrode active layer composition comprises positive electrode active coated particles and positive electrode electrolyte particles. Each positive electrode active coated particle comprises a positive electrode active core, and a first coating sub-layer and a second coating sub-layer that coat at least a part of the surface of the positive electrode active core, and the first coating sub-layer is located between the positive electrode active core and the second coating sub-layer. The positive electrode active core comprises an oxide positive electrode active material. The first coating sub-layer comprises a non-carbon conductive material. The second coating sub-layer comprises a solid electrolyte material. At least one of the positive electrode electrolyte particles and the second coating sub-layers comprises a sulfide electrolyte.

Description

Positive electrode active layer composition, positive electrode active coated particles, positive electrode film, solid-state battery, electrical device and application

[0001] Related applications

[0002] This application claims priority to Chinese patent application number CN2024102696321, filed on March 8, 2024, entitled “Positive electrode active layer composition, positive electrode active coated particles, positive electrode film, solid-state battery, electrical device and application,” the entire text of which is hereby incorporated by reference. Technical Field

[0003] The present application relates to the technical field of solid-state batteries, and further to a positive electrode active layer composition, positive electrode active coated particles, a positive electrode film, a solid-state battery, an electrical device and applications. Background Art

[0004] The statements herein merely provide background information related to the present application and do not necessarily constitute prior art.

[0005] Solid-state batteries use non-flammable solid electrolytes instead of the organic electrolytes found in traditional liquid secondary batteries, significantly improving battery safety and are considered the next generation of batteries closest to industrialization. However, poor interfacial contact and side reactions are among the pain points that limit solid-state batteries' performance, resulting in suboptimal discharge capacity, rate capability, and cycle performance.

[0006] Summary of the Invention

[0007] According to various embodiments and examples of the present application, the present application provides a positive electrode active layer composition, positive electrode active coated particles, a positive electrode film, a solid-state battery, an electrical device, and applications. The positive electrode active layer composition can be used to form a positive electrode active material layer in a positive electrode layer included in a positive electrode film or a solid-state battery. A solid-state battery prepared using the positive electrode active layer composition can have good discharge capacity, rate performance, and cycle performance.

[0008] In a first aspect of the present application, a positive electrode active layer composition is provided.

[0009] In some embodiments, a positive electrode active layer composition is provided, which includes positive electrode active coating particles and positive electrode electrolyte particles; the positive electrode active coating particles include a positive electrode active body and a first coating sublayer and a second coating sublayer coated on at least a portion of the surface of the positive electrode active body, and the first coating sublayer is located between the positive electrode active body and the second coating sublayer; the positive electrode active body includes an oxide positive electrode active material; the first coating sublayer includes a non-carbon conductive material; the second coating sublayer includes an electrolyte solid; at least one of the positive electrode electrolyte particles and the second coating sublayer contains a sulfide electrolyte.

[0010] In some embodiments, a positive electrode active layer composition is provided, which includes positive electrode active coating particles and positive electrode electrolyte particles;

[0011] The positive electrode active coated particles include a positive electrode active body and a coating layer coated on at least a portion of the surface of the positive electrode active body, the coating layer includes a first coating sublayer and a second coating sublayer, and the second coating sublayer is located on a side of the first coating sublayer away from the positive electrode active body;

[0012] The positive electrode active body includes a positive electrode active material, and the positive electrode active material includes an oxide positive electrode active material;

[0013] The first coating sublayer includes a non-carbon conductive material, and the non-carbon conductive material includes at least one of a Se element, a Te element, and a Se / Te complex, wherein the chemical formula of the Se / Te complex is Se x Te 1-x , 0 <x<1;

[0014] The second coating sublayer includes an electrolyte solid;

[0015] At least one of the positive electrode electrolyte particles and the second coating sublayer includes a sulfide electrolyte.

[0016] The positive electrode active layer composition includes positive electrode active coated particles having a multi-layer coating structure and positive electrode electrolyte particles, wherein the inner core of the positive electrode active coated particles is a positive electrode active body containing an oxide positive electrode active material (such as a lithium transition metal oxide), and a first coating sublayer containing a non-carbon conductive material and a second coating sublayer containing an electrolyte solid are sequentially arranged on the surface of the positive electrode active body, and at least one of the positive electrode electrolyte particles and the second coating sublayer contains a sulfide electrolyte component, that is, the oxide positive electrode active material (such as a lithium transition metal oxide) in the positive electrode active coated particles is separated from the sulfide electrolyte contained in the positive electrode active layer composition by at least the first coating sublayer, and the sulfide electrolyte contained in the positive electrode active layer composition can be located in the positive electrode electrolyte particles or in the second coating sublayer of the positive electrode active coated particles.

[0017] The non-carbon conductive material in the first coating sublayer includes a first conductive material, which is at least one of a single substance of Se, a single substance of Te, and a Se / Te complex, and is composed of one or both of selenium (Se) and tellurium (Te). Se and Te both have high electronic conductivity, with the electronic conductivity of Se being approximately 10 mS / cm and that of Te being approximately 2000 mS / cm. This allows the non-carbon conductive material to provide good electronic conductivity and can be used in the positive electrode film or the positive electrode layer of a solid-state battery. Within the electrochemical operating window of the oxide positive electrode active material (such as a lithium transition metal oxide) (e.g., 2.8 V to 4.3 V), selenium (Se) and tellurium (Te) have almost no electrochemical activity, contribute little to the capacity, and can basically not participate in the electrochemical reaction, thereby maintaining stable electronic conductivity. In addition, Se and Te are elements in the same main group as sulfur (S), and have good compatibility with sulfide electrolytes.

[0018] By utilizing the isolation effect of the first conductive material in the first coating sublayer on the oxide positive electrode active material (such as lithium transition metal oxide) and the sulfide electrolyte, the direct contact and interface side reactions between the oxide positive electrode active material (such as lithium transition metal oxide) and the sulfide electrolyte can be reduced or blocked. The superoxide ions (O2 2- ) or oxygen radicals can react with Se and / or Te in non-carbon conductive materials to generate SeO3 2- and / or TeO3 2- This reaction can inhibit the release of oxygen from oxide positive electrode active materials (such as lithium transition metal oxides), reduce the oxidative decomposition of sulfide electrolytes, improve the structural stability of positive electrode active particles and the electrochemical performance of the battery, and the prepared solid-state battery can have high discharge capacity, high rate performance and good cycle performance at the same time.

[0019] A second coating sublayer is further provided in the positive electrode active particles provided with the first coating sublayer. The ion conductivity provided by the electrolyte solid in the second coating sublayer can be utilized to enhance the interface contact between the positive electrode active material and the positive electrode electrolyte particles, thereby enhancing the ion conduction between the positive electrode active coating particles and the positive electrode electrolyte particles, reducing the interface impedance, and improving the battery performance.

[0020] The first coating sublayer can provide higher electronic conductivity, and the electrolyte solid in the second coating sublayer can improve interfacial ion transport, so that the positive electrode active layer composition has both higher electronic conductivity and good ion conductivity. This structural design can also simultaneously inhibit the release of oxygen by the oxide positive electrode active material (such as lithium transition metal oxide), which can give the corresponding solid-state battery higher discharge capacity and rate performance, and can improve the cycle performance of the solid-state battery.

[0021] By utilizing the multiple synergistic effects between solid-state positive electrode coating particles and positive electrode electrolyte particles, a good and stable electrical contact network can be formed in the positive electrode active material layer, reducing the interfacial impedance, promoting the charge transfer efficiency between the positive electrode active material and the outside world and the full release of its capacity, and can be used to prepare solid-state batteries with high discharge capacity, high rate performance and good cycle performance.

[0022] In some embodiments, the electronic conductivity of the non-carbon conductive material at at least one temperature between 20° C. and 100° C. or at least a portion of the temperature range is greater than or equal to that of Se elemental substance.

[0023] In some embodiments, the weight percentage of Te element in the non-carbon conductive material is 50 wt % to 100 wt %, and can be optionally 60 wt % to 100 wt %.

[0024] Te has a high electronic conductivity (approximately 2000mS / cm), which is roughly the same order of magnitude as that of traditional carbon black materials (for example, carbon black has an electronic conductivity of approximately 10S / cm to 100S / cm), providing excellent electronic conductivity. By adding a higher proportion of Te to non-carbon conductive materials, it is beneficial to prepare solid-state batteries with higher discharge capacity, higher rate performance, and better cycle performance.

[0025] The first conductive material is "at least one of a Se element, a Te element, and a Se / Te complex". In some embodiments, the weight percentage of the first conductive material in the non-carbon conductive material is 80 wt% to 100 wt%, and optionally 90 wt% to 100 wt%.

[0026] By controlling the weight percentage of the first conductive material in the non-carbon conductive material within the aforementioned range, the first conductive material can better play the role of inhibiting the release of oxygen from the oxide positive electrode active material (such as lithium transition metal oxide), which is conducive to preparing a solid-state battery with higher discharge capacity, higher rate performance and better cycle performance.

[0027] In some embodiments, the positive electrode active coated particles meet one or more of the following characteristics:

[0028] The weight percentage of the first coating sublayer in the positive electrode active coating particles is 0.1wt% to 10wt%, and can be optionally 0.5wt% to 5wt%;

[0029] The weight percentage of the non-carbon conductive material in the first coating sublayer is 80wt% to 100wt%, and can be optionally 90wt% to 100wt%;

[0030] The thickness of the first cladding sublayer is 0.1 nm to 50 nm, and can be optionally 0.5 nm to 10 nm.

[0031] By adjusting at least one of the parameters of the weight percentage of the first coating sublayer in the positive electrode active coating particles, the weight percentage of the non-carbon conductive material in the first coating sublayer and the thickness of the first coating sublayer within the aforementioned range, it is more conducive to forming a good and stable electrical contact network and reducing the interface impedance while also improving the structural stability of the positive electrode active material, which is more conducive to enabling solid-state batteries to achieve higher discharge capacity, higher rate performance and better cycle performance.

[0032] In some embodiments, the sulfide electrolyte includes one or more of an argyrodite-type sulfide electrolyte, an LGPS-type sulfide electrolyte, and a lithium sulfide pentasulfide diphosphorus complex-type sulfide electrolyte.

[0033] In some embodiments, the sulfide electrolyte satisfies one or more of the following characteristics:

[0034] The argyrodite-type sulfide electrolyte includes a chemical formula of Li 6±s P 1-j A j S 5±s-t B t X 1±s A sulfide electrolyte, wherein 0≤j<1, 0≤t<1, 0≤s<1, A is selected from one or more elements of Ge, Si, Sn and Sb, B is selected from one or more elements of O, Se and Te, and X is selected from one or more elements of Cl, Br, I and F;

[0035] The LGPS sulfide electrolyte includes a chemical formula of Li 10±δ5 Ge 1-g G g P 2-q Q q S 12-w W w A sulfide electrolyte, wherein 0≤δ5<1, 0≤g≤1, 0≤q≤2, 0≤w<1, G is one or two elements of Si and Sn, Q is Sb, and W is one or more elements selected from O, Se, Te, Cl, Br, I and F;

[0036] The lithium sulfide pentasulfide phosphorus sulfide composite sulfide electrolyte includes a chemical formula of (100-uv)Li2S·uP2S5·vM m N nA sulfide electrolyte, where 0 < u < 100, 0 ≤ v < 100, 0 ≤ u + v < 100, 0 ≤ m < 4, 0 ≤ n < 6, M is selected from one or more elements of Li, B, Ge, Si, Sn, and Sb, and N is selected from one or more elements of S, Se, Te, O, Cl, Br, I, and F.

[0037] For the case where at least one of the positive electrode electrolyte particles in the positive electrode layer of the solid-state battery and the second coating sub-layer includes the various sulfide electrolytes described above, the oxidation decomposition of the sulfide electrolyte at the positive electrode under high voltage can be suppressed through the multi-layer coating structure design of the positive electrode active coating particles, thereby improving the discharge capacity, rate performance, and cycle performance of the solid-state battery. In addition, the first Coulomb efficiency of the solid-state battery can also be increased.

[0038] In some embodiments, the positive electrode active coating particles satisfy one or more of the following characteristics:

[0039] The weight percentage of the second coating sub-layer in the positive electrode active coating particles is 0.1 wt% to 10 wt%, optionally 0.5 wt% to 5 wt%;

[0040] The weight percentage of the electrolyte solid in the second coating sub-layer is 50 wt% to 100 wt%, optionally 80 wt% to 100 wt%, and further optionally 90 wt% to 100 wt%;

[0041] The electrolyte solid includes a sulfide-based electrolyte, and the weight percentage of the sulfide-based electrolyte in the electrolyte solid is 50 wt% to 100 wt%, optionally 80 wt% to 100 wt%, and further optionally 90 wt% to 100 wt%;

[0042] The thickness of the second coating sub-layer is 0.1 nm to 50 nm, optionally 0.5 nm to 10 nm.

[0043] By adjusting at least one parameter of the weight percentage of the second coating sub-layer in the positive electrode active coating particles, the weight percentage of the electrolyte solid in the second coating sub-layer, and the thickness of the second coating sub-layer within the above ranges, it is more conducive to forming a good and stable electrical contact network while better reducing the interfacial impedance, and is more conducive to enabling the solid-state battery to achieve a higher discharge capacity, a higher rate performance, and a better cycle performance.

[0044] In some embodiments, the positive electrode active layer composition satisfies any one of the following situations:

[0045] Both the positive electrode electrolyte particles and the second coating sub-layer contain sulfide electrolytes;

[0046] One of the positive electrode electrolyte particles and the second coating sublayer comprises a sulfide electrolyte, and the other is an optional solid electrolyte.

[0047] In some embodiments, one of the cathode electrolyte particle and the second coating sublayer comprises a sulfide electrolyte, and the other comprises one or more of a sulfide electrolyte, a halide electrolyte, an oxide electrolyte, and a polymer electrolyte.

[0048] The sulfide electrolyte can be provided in the second coating sublayer of the positive electrode active coating particles, in the positive electrode electrolyte particles, or in both locations. When a sulfide electrolyte is provided in one of the two locations, the type of solid electrolyte contained in the other location is not particularly limited and can be flexibly selected based on needs.

[0049] In some embodiments, the second coating sublayer comprises a sulfide electrolyte.

[0050] By providing a sulfide electrolyte in the second coating sublayer of the positive electrode active coating particles, the positive electrode active particles can be endowed with high ion conductivity, which can greatly improve the interface ion conduction, thereby improving the electrochemical performance of the battery.

[0051] In some embodiments, the positive electrode active layer composition satisfies one or more of the following characteristics:

[0052] The second coating sublayer includes a sulfide-based electrolyte, and the weight percentage of the sulfide-based electrolyte in the second coating sublayer is 80wt% to 100wt%, and optionally 90wt% to 100wt%;

[0053] The positive electrode electrolyte particles include a sulfide-based electrolyte, and the weight percentage of the sulfide-based electrolyte in the positive electrode electrolyte particles is 80 wt % to 100 wt %, and can be optionally 90 wt % to 100 wt %.

[0054] By controlling at least one of the weight percentage of the sulfide-based electrolyte in the second coating sublayer and the weight percentage of the sulfide-based electrolyte in the positive electrode electrolyte particles within the aforementioned range, it is beneficial to better improve the ion transport of the positive electrode active material layer and to reduce the interfacial impedance within the positive electrode active material layer.

[0055] In some embodiments, the mass ratio of the positive electrode electrolyte particles to the positive electrode active coating particles is 1% to 67%, optionally 1% to 45%, or optionally 5% to 25%.

[0056] The mass ratio of the positive electrode electrolyte particles to the positive electrode active coating particles can be controlled within the aforementioned range, which is beneficial for better providing overall electron and ion conductivity while taking into account high energy.

[0057] In some embodiments, the oxide cathode active material includes a lithium transition metal oxide;

[0058] Optionally, the lithium transition metal oxide includes one or more of a lithium cobalt oxide type cathode active material, a high-nickel cathode active material, a lithium-rich manganese-based cathode active material, and a modified form of any one of the foregoing cathode active materials; the modified form includes one or more of doping modification and coating modification;

[0059] Among them,

[0060] The lithium cobalt oxide type cathode active material contains Li element, Co element and O element. Among them, the atomic molar ratio of Co element and O element is x2:2, and 0.9 ≤ x2 ≤ 1; optionally, the lithium cobalt oxide type cathode active material contains Li element, Co element and O element with an atomic molar ratio of 1:x2:2, and 0.9 ≤ x2 ≤ 1;

[0061] The high-nickel cathode active material contains Li element, Ni element and O element. Among them, the atomic molar ratio of Ni element and O element is y2:2, and 0.6 ≤ y2 ≤ 1; optionally, the high-nickel cathode active material contains Li element, Ni element and O element with an atomic molar ratio of 1:y2:2, and 0.6 ≤ y2 ≤ 1. Optionally, 0.8 ≤ y2 ≤ 1;

[0062] The lithium-rich manganese-based cathode active material contains Li element, Mn element and O element with an atomic molar ratio of (1 + p):(p + r(1 - p):(2 + p)), and 0 < p ≤ 1, 0 ≤ r ≤ 1; optionally, 0.2 ≤ p ≤ 1.

[0063] In some embodiments, the lithium transition metal oxide satisfies one or more of the following characteristics:

[0064] The lithium cobalt oxide type cathode active material includes a lithium transition metal oxide with the chemical formula LiCo x2 R 1-x2 O2, and R is selected from one or more elements of Ni, Mg, Ti, Al, Cr, Fe, Nb and Ta;

[0065] The high-nickel cathode active material includes a lithium transition metal oxide with the chemical formula LiNi y2 Co z2 D 1-y2-z2 O2, 0 ≤ z2 ≤ 0.4, 0.6 ≤ (y2 + z2) ≤ 1, and D is selected from one or more elements of Mn, Al, Zr, La, Ce, Ti, Mg, Nb, Ta, Mo and W; optionally, D includes Mn element;

[0066] The lithium-rich manganese-based cathode active material includes a lithium transition metal oxide with the chemical formula pLi2MnO3·(1-p)LiZO2, where Z is selected from one or more elements of Ni, Co, Mn, Cr, Fe, Al, Nb, Mo, and Ru.

[0067] As a non-limiting example of the oxide cathode active material, lithium transition metal oxides such as lithium cobalt oxide-type cathode active material, high-nickel cathode active material, and lithium-rich manganese-based cathode active material are prone to releasing oxygen at high working voltages. When these lithium transition metal oxides are used as the cathode active material in the cathode active particles, by arranging the aforementioned cathode active layer composition in the cathode active material layer, it is beneficial to achieve both high energy density and long cycle performance of the sulfide solid-state battery under the condition of possible oxygen release at the cathode.

[0068] When the cathode active material layer includes the aforementioned cathode active coated particles, further, it is also beneficial to inhibit the oxygen release of the cathode material, improve the crystal structure stability of the cathode active particles during battery cycling, inhibit the formation of the surface rock salt phase, and is beneficial to fully exert the cathode capacity and improve the long cycle performance of the battery.

[0069] In some embodiments, the oxide cathode active material includes one or more of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium-rich manganese cathode active material, and modified forms of any of the aforementioned lithium transition metal oxides; wherein, the chemical formula of the lithium-rich manganese cathode active material is pLi2MnO3·(1-p)LiZO2, Z is selected from one or more elements of Ni, Co, Mn, Cr, Fe, Al, Nb, Mo, and Ru, and 0 < p ≤ 1; the modified forms include one or more of doping modification and coating modification.

[0070] The structural design of introducing cathode active coated particles can be adopted in the cathode active particles containing the aforementioned different types of oxide cathode active materials (such as lithium transition metal oxides), which can play the role of improving the discharge capacity, rate performance, and cycle performance of the solid-state battery as described above.

[0071] In some embodiments, the D v 50 of the cathode electrolyte particles or the particle size is 1 nm to 20 μm, and can be selected as 50 nm to 5 μm; wherein, D v 50 represents the particle size corresponding to when the cumulative volume distribution percentage of the multi-particle mixture reaches 50%, and the particle size refers to the maximum diameter among the diameters in all directions of the particles.

[0072] By adjusting the D v50 or particle size within the aforementioned range is beneficial to better improve the interface contact between the positive electrode layer and the battery layer while taking into account the overall ion conductivity of the positive electrode electrolyte particles, better improve the electrochemical performance of the battery, and take into account the manufacturing cost. The relatively small particle size of the positive electrode electrolyte particles is beneficial to improve the electrical contact between the positive electrode active materials in the positive electrode active particles, thereby promoting the capacity and rate performance of the solid-state battery. The relatively moderate D of the positive electrode electrolyte particles v 50 or more particle size is easier to manufacture.

[0073] In some embodiments, the D of the positive electrode active coating particles v 50 or particle size is 0.1μm~20μm, optionally 1μm~10μm; wherein, D v 50 represents the particle size corresponding to when the cumulative volume distribution percentage of the multi-particle mixture reaches 50%.

[0074] By controlling the D v 50 or particle size within the above range is beneficial to improving the discharge capacity of the positive electrode active material and maintaining good contact between the positive electrode active material and the sulfide electrolyte in the composite positive electrode. Smaller-sized positive electrode active materials have shorter lithium ion transmission channels, which is beneficial to improving the discharge capacity of the positive electrode active material itself; larger-sized positive electrode active materials can be better wrapped by the sulfide electrolyte, and have better interfacial contact with the sulfide solid electrolyte, which is beneficial to the battery's cycling performance. Relatively moderate-sized positive electrode materials can enable solid-state batteries to have both high discharge capacity and excellent cycling performance.

[0075] In a second aspect of the present application, a positive electrode active coated particle is provided, which is the positive electrode active coated particle included in the positive electrode active layer composition described in the first aspect of the present application, and the second coating sublayer contains a sulfide electrolyte.

[0076] The positive electrode active coated particles can be applied to the positive electrode active material layer of a solid-state battery, so that the corresponding sulfide solid-state battery can have good discharge capacity, rate performance and cycle performance.

[0077] In a third aspect of the present application, a positive electrode film is provided.

[0078] In some embodiments, a positive electrode film is provided, comprising a positive electrode current collector and a positive electrode active material layer located on at least one side of the positive electrode current collector, wherein the positive electrode active material layer comprises the positive electrode active layer composition described in the first aspect of the present application.

[0079] In some embodiments, a positive electrode film is provided, which includes a positive electrode current collector and a positive electrode active material layer located on at least one side of the positive electrode current collector, wherein the positive electrode active material layer includes the positive electrode active coated particles described in the second aspect of the present application.

[0080] In some embodiments, the positive electrode active material layer satisfies one or more of the following characteristics:

[0081] The weight percentage of the positive electrode active coating particles in the positive electrode active material layer is 70wt% to 99wt%, and can be optionally 80wt% to 95wt%;

[0082] The weight percentage of the positive electrode electrolyte particles in the positive electrode active material layer is 0.1 wt% to 30 wt%, and can be optionally 5 wt% to 20 wt%.

[0083] By controlling the weight percentage of the positive electrode active coating particles in the positive electrode active material layer within the above range, it is advantageous to achieve both high energy density and cycle stability.

[0084] The weight percentage of the positive electrode electrolyte particles in the positive electrode active material layer can be controlled within the aforementioned range, which is beneficial for better providing overall ion conductivity.

[0085] In some embodiments, the positive electrode active material layer further comprises one or more of a binder and a conductive agent;

[0086] Optionally, the cathode film satisfies one or more of the following characteristics:

[0087] The weight percentage of the binder in the positive electrode active material layer is 0.1 wt% to 5 wt%;

[0088] The weight percentage of the conductive agent in the positive electrode active material layer is 0.1 wt % to 5 wt %.

[0089] In a fourth aspect of the present application, there is provided a solid-state battery comprising a positive electrode layer, a solid electrolyte layer and a negative electrode layer;

[0090] The positive electrode layer includes at least one of the positive electrode active layer composition described in the first aspect of the present application, the positive electrode active coated particles described in the second aspect of the present application, and the positive electrode film described in the third aspect of the present application.

[0091] In some embodiments, the solid-state battery is a sulfide solid-state battery.

[0092] In some embodiments, the solid-state battery is a sulfide all-solid-state battery.

[0093] In the fifth aspect of the present application, an electrical device comprises at least one of the positive electrode film described in the third aspect of the present application and the solid-state battery described in the fourth aspect of the present application.

[0094] Use of the positive electrode active layer composition described in the first aspect of the present application, or the positive electrode active coated particles described in the second aspect of the present application, or the positive electrode film described in the third aspect of the present application in the preparation of a solid-state battery;

[0095] Optionally, the solid-state battery is a sulfide solid-state battery;

[0096] Further optionally, the solid-state battery is a sulfide all-solid-state battery.

[0097] The details of one or more embodiments of the present application are set forth in the following drawings and description. Other features, objects, and advantages of the present application will become apparent from the description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0098] In order to better describe and illustrate the embodiments or examples provided in this application, reference may be made to one or more of the accompanying drawings. The additional details or examples used to describe the accompanying drawings should not be considered as limiting the scope of the disclosed application, the embodiments or examples currently described, and any of the best modes currently understood for these applications. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the accompanying drawings:

[0099] Figure 1 is a schematic structural diagram of the positive electrode active coated particles in an embodiment of the present application, wherein the positive electrode active coated particles include a positive electrode active body and a first coating sublayer and a second coating sublayer located on the surface of the positive electrode active body, wherein the second coating sublayer is located on the side surface of the first coating sublayer away from the positive electrode active body (that is, the first coating sublayer is located between the positive electrode active body and the second coating sublayer).

[0100] Figure 2 is a schematic structural diagram of the positive electrode active coated particles in an embodiment of the present application, wherein the positive electrode active coated particles include a positive electrode active body and a first coating sublayer and a second coating sublayer located on the surface of the positive electrode active body, the first coating sublayer is located between the positive electrode active body and the second coating sublayer, the positive electrode active body includes an oxide positive electrode active material, the first coating sublayer includes a non-carbon conductive material, and the second coating sublayer includes an electrolyte solid.

[0101] Figure 3 is a schematic diagram of the composition of a positive electrode active layer composition that can be used to prepare a positive electrode active material layer in one embodiment of the present application. The positive electrode active layer composition includes positive electrode active coating particles and positive electrode electrolyte particles, wherein the second coating sublayer of the positive electrode active coating particles contains sulfide electrolyte.

[0102] FIG4 is a schematic diagram of the composition of a positive electrode active layer composition that can be used to prepare a positive electrode active material layer in one embodiment of the present application. The positive electrode active layer composition includes positive electrode active coated particles and a sulfide-based electrolyte.

[0103] Figure 5 is a schematic diagram of the composition of a positive electrode active layer composition that can be used to prepare a positive electrode active material layer in one embodiment of the present application. The positive electrode active layer composition includes positive electrode active coated particles and a sulfide-based electrolyte, wherein the second coating sublayer of the positive electrode active coated particles contains a sulfide electrolyte, and the sulfide-based electrolyte also contains a sulfide electrolyte.

[0104] FIG6 is a schematic diagram of the composition of a positive electrode active layer composition that can be used to prepare a positive electrode active material layer in one embodiment of the present application. The positive electrode active layer composition includes positive electrode active coated particles, wherein the second coating sublayer of the positive electrode active coated particles contains a sulfide electrolyte.

[0105] Figure 7 is a structural schematic diagram of a "positive electrode active coated particle whose second coating sublayer comprises a sulfide electrolyte" in one embodiment of the present application, in which the second coating sublayer of the positive electrode active coated particle comprises a sulfide electrolyte (that is, the second coating sublayer comprises a sulfide-based electrolyte), the positive electrode active body comprises an oxide positive electrode active material, and the first coating sublayer comprises a non-carbon conductive material.

[0106] FIG8 is a schematic structural diagram of a positive electrode film according to an embodiment of the present application, wherein the positive electrode film includes a positive electrode current collector and a positive electrode active material layer located on one side of the positive electrode current collector.

[0107] FIG9 is a schematic structural diagram of a positive electrode film according to an embodiment of the present application, wherein the positive electrode film includes a positive electrode current collector and positive electrode active material layers located on both sides of the positive electrode current collector.

[0108] FIG10 is a schematic structural diagram of a solid-state battery cell according to an embodiment of the present application, wherein the solid-state battery cell includes a positive electrode layer, a solid electrolyte layer, and a negative electrode layer stacked in sequence.

[0109] Figure 11 is a structural schematic diagram of an embodiment of the solid-state battery cell shown in Figure 10, which includes a positive electrode layer, a solid electrolyte layer and a negative electrode layer stacked in sequence, wherein the positive electrode layer includes a positive electrode film according to an embodiment of the present application, the positive electrode film includes a positive electrode current collector and a positive electrode active material layer located on both sides of the positive electrode current collector, and a positive electrode active material layer is arranged between the positive electrode current collector and the solid electrolyte layer.

[0110] FIG12 is a schematic diagram of a solid-state battery cell according to an embodiment of the present application.

[0111] FIG13 is an exploded view of the solid-state battery cell according to one embodiment of the present application shown in FIG12 .

[0112] FIG14 is a schematic diagram of a battery module according to an embodiment of the present application.

[0113] FIG15 is a schematic diagram of a battery pack according to an embodiment of the present application.

[0114] FIG16 is an exploded view of the battery pack shown in FIG15 according to an embodiment of the present application.

[0115] FIG17 is a schematic diagram of an electrical device using a solid-state battery as a power source according to an embodiment of the present application.

[0116] Figure 18 is a transmission electron microscope (TEM) image of the positive electrode active coated particles prepared by the method of the present application. The positive electrode active coated particles shown in the figure include two coating sublayers. The first coating sublayer is composed of Se element and has a thickness of about 2 nm. The second coating sublayer is composed of LPSCl and has a thickness of about 4 nm. The positive electrode active coated particles are also recorded as "double-layer coated NCM811@Se@LPSCl".

[0117] Figure 19 is the EDS energy spectrum data of the positive electrode active coated particles (double-layer coated NCM811@Se@LPSCl) shown in Figure 18, showing the high-angle annular dark field (HAADF) image and the corresponding energy spectrum scanning results of Ni, S and Se elements.

[0118] Description of reference numerals:

[0119] 80, positive electrode active coated particles; 82, positive electrode active body; 84, first coating sublayer; 86, second coating sublayer; 802, oxide positive electrode active material; 804, non-carbon conductive material; 806, electrolyte solid; 662, sulfide-based electrolyte; 80a, positive electrode active coated particles containing sulfide electrolyte in the second coating sublayer; 200, positive electrode layer; 20, positive electrode film; 210, positive electrode current collector; 220, positive electrode active material layer; 66, positive electrode electrolyte particles; 100, solid electrolyte layer; 300, negative electrode layer; 1, battery pack; 2, upper case; 3, lower case; 4, battery module; 5, solid-state battery cell; 51, shell; 52, solid-state battery cell; 53, cover plate; 6, electrical device.

[0120] It can be understood that in the various drawings, the drawn sizes of structures such as the solid-state battery cell 52, the positive electrode film 20, the positive electrode current collector 210, the positive electrode active material layer 220, the positive electrode layer 200, the positive electrode active material layer 220, the solid electrolyte layer 100, and the negative electrode layer 300 do not represent the actual sizes; the shapes and sizes of the positive electrode active coated particles 80, the positive electrode active coated particles 80a whose second coating sublayer contains a sulfide electrolyte, the positive electrode active body 82, the first coating sublayer 84, the second coating sublayer 86, the oxide positive electrode active material 802, the non-carbon conductive material 804, the electrolyte solid 806, the positive electrode electrolyte particles 66, the sulfide-based electrolyte 662 and other substances or local structures of the substances involved in the various drawings do not represent or are not used to limit the shapes and sizes of the actual substances, and the numbers shown in the drawings do not represent or are not used to limit the actual numbers and quantity ratios. DETAILED DESCRIPTION

[0121] Below, some embodiments of the positive electrode active layer composition, positive electrode active coated particles, positive electrode film, solid-state battery, electrical device and application of the present application are described in detail with appropriate reference to the drawings. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there are cases where detailed descriptions of well-known matters and repeated descriptions of actually the same 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 application and are not intended to limit the subject matter described in the claims.

[0122] " scope " disclosed in the present application can be limited in the form of lower limit and upper limit, and given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of special range. The scope limited in this way can be to include end value or not include end value, and any end value can be included or not included independently, and can be arbitrarily combined, that is, any lower limit can form a scope with any upper limit combination. For example, if the scope of 60-120 and 80-110 is listed for specific parameters, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if minimum range values ​​1 and 2 are listed, and if maximum range values ​​3,4 and 5 are also listed, then the following scope can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present application, unless otherwise specified, numerical range " ab " represents the abbreviation of any real number combination between a and b, wherein a and b are all real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" are listed herein, and "0-5" is merely an abbreviation for these numerical combinations. Furthermore, when a parameter is expressed as an integer ≥ 2, this is equivalent to listing the parameter as, for example, the integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, and so on. For example, when a parameter is expressed as an integer selected from "2-10", this is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0123] In this application, unless otherwise specified, "about" means within a reasonable range above or below the number. The fluctuation range may vary depending on the type and value of the number. For example, a range of ±10%, ±5%, ±2%, ±1%, etc. may be allowed. For example, taking "about 20°C" and its approximate value of ±1°C as an example, approximate values ​​such as 19°C and 19.5°C within the approximate range of "about 20°C" should also be included in the range indicated by "about 20°C".

[0124] In this application, references to "multiple," "multiple," "multiple," "several," and the like, unless otherwise specified, refer to a quantity greater than or equal to two. For example, "one or more" means one or ≥ (greater than or equal to) two. It is understood that references to "any number" of items refer to any suitable combination of multiple items, i.e., any combination of "any number" of items that is not in conflict and that enables the implementation of this application.

[0125] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0126] References to "embodiments" herein mean that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment or implementation of the present application. The appearance of such phrases in various locations in the specification does not necessarily refer to the same embodiment, nor does it necessarily refer to independent or alternative embodiments that are mutually exclusive with other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments. References to "implementations" herein have a similar understanding.

[0127] Those skilled in the art will appreciate that, in the methods of each embodiment or embodiment, the order in which each step is written does not mean a strict order of execution and constitutes any limitation to the implementation process, and the detailed order of execution of each step should be determined by its function and possible inherent logic. Unless otherwise specified, all steps of the present application can be performed in sequence, or can be performed randomly, or can preferably be performed in sequence. For example, method M includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed in sequence, or steps (b) and (a) performed in sequence. For example, method M may also include step (c), indicating that step (c) can be added to method M in any order, for example, method M may include steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0128] In this application, in open technical features or technical solutions described with words such as "contain," "include," and "include," unless otherwise specified, additional members other than the listed members are not excluded, and it can be regarded as providing both closed features or solutions consisting of the listed members and open features or solutions including additional members in addition to the listed members. For example, A includes a1, a2, and a3. Unless otherwise specified, it may also include other members or not. It can be regarded as providing both the feature or solution of "A consists of a1, a2, and a3" or "A is selected from a1, a2, and a3", and the feature or solution of "A includes not only a1, a2, and a3, but also other members."

[0129] In this application, unless otherwise specified, A (such as B) means that B is a non-limiting example of A, and it can be understood that A is not limited to B.

[0130] In this application, "optionally," "optional," and "optional" mean optional, that is, they refer to either option selected from the two parallel options of "yes" or "no." If multiple "options" appear in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "optional" is independent. Unless otherwise specified, the descriptions "optionally include," "optionally include," etc. in this application, using "optionally include" as an example, mean "may include or not include."

[0131] In this application, unless otherwise specified, the features or solutions corresponding to "and / or" include any one of two or more relevant listed items, and also include any and all combinations of the relevant listed items, wherein any and all combinations include any two relevant listed items, any more relevant listed items, or a combination of all relevant listed items. For example, "A and / or B" means a group consisting of A, B, and "a combination of A and B." Among them, "including A and / or B" can mean "including A, including B, and including A and B", and can also mean "including A, including B, or including A and B", which can be appropriately understood according to the sentence in which it is used.

[0132] As used herein, "combination thereof", "any combination thereof", "any combination thereof" and the like include all suitable combinations of any two or more of the listed items.

[0133] Herein, the word “suitable” in “suitable combination”, “suitable method”, “any suitable method”, etc., shall be based on the technical solution that can implement the present application.

[0134] Herein, the terms "preferred," "better," "more preferable," "suitable," "comparatively better," and "preferable" are used solely to describe preferred implementations or examples and should not be construed as limiting the scope of protection of this application. If multiple "preferred" terms appear in a technical solution, each "preferred" term is considered independent unless otherwise specified and there are no contradictions or mutual constraints.

[0135] In this application, "further", "further", "particularly", "for example", "such as", "example", "for example", etc. are used for descriptive purposes to indicate differences in content, but should not be understood as limiting the scope of protection of this application.

[0136] In this application, the terms "first", "second", "third", "fourth", "fifth", etc. in "the first aspect", "the second aspect", "the third aspect", "the fourth aspect", "the fifth aspect", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or quantity, nor should they be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first", "second", "third", "fourth", "fifth", etc. only serve the purpose of non-exhaustive enumeration and description, and should be understood not to constitute a closed limitation on quantity.

[0137] In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may refer to a relative horizontal positional relationship, or may simply refer to an attachment relationship without limiting the relative horizontal positional relationship.

[0138] In this application, the term "room temperature" generally refers to 4°C to 35°C, and may refer to 20°C ± 5°C. In some embodiments or examples of this application, room temperature refers to 20°C to 30°C.

[0139] In this application, when referring to a data range, if the unit is followed only by the right endpoint, it means that the units of the left and right endpoints are the same. For example, "3~5h" or "3-5h" both mean that the units of the left endpoint "3" and the right endpoint "5" are both hours, and both have the same meaning as "3h~5h". Similarly, descriptions of other parameters such as temperature and size are to be understood in the same manner.

[0140] The weight or mass of the relevant components mentioned in the embodiments or examples of the present application can not only refer to the content of each component, but also represent the proportional relationship of weight or mass between each component. Therefore, as long as the content of the relevant components in accordance with the embodiments or examples of the present application is proportionally enlarged or reduced, it is within the scope described in the present application. Further, the mass involved in the embodiments or examples of the present application can be mass units known to the chemical industry such as micrograms (μg), milligrams (mg), grams (g), kilograms (kg). Unless otherwise specified, the mass ratio is equal to the corresponding weight ratio, such as the mass of substance A is m1 and the weight is W1, the mass of substance B is m2 and the weight is W2, then the mass ratio m1 / m2 of the two is numerically equal to the corresponding weight ratio W1 / W2.

[0141] In this application, unless otherwise specified, wt% represents weight percentage by weight and is numerically equivalent to the corresponding mass percentage by mass. In this application, when a weight percentage is represented by "0", it has the same meaning as "0wt%" and can be used interchangeably.

[0142] The units of parameters involved in this application, unless otherwise specified, are nm for nanometers, μm for micrometers, S / cm for Siemens per centimeter, V for volts, mPa·S for millipascals per second, and mg / cm 2 Expressed in milligrams per square centimeter, g / cm 2 Indicates grams per square centimeter, g / cm 3 represents grams per cubic centimeter, ℃ represents degrees Celsius, mA / g represents milliampere per gram, and mAh / g represents milliampere-hour per gram.

[0143] In this application, "greater than or equal to", "greater than or equal to", and "≥" have the same meaning and can be used interchangeably; "less than or equal to", "less than or equal to", and "≤" have the same meaning and can be used interchangeably; "greater than" can be equivalently expressed as ">", and "less than" can be equivalently expressed as "<". In this application, unless otherwise specified, "greater than or equal to" and "≥" can be regarded as providing two solutions of "greater than" and "equal to". In this application, unless otherwise specified, "less than or equal to" and "≤" can be regarded as providing two solutions of "less than" and "equal to".

[0144] In this application, exemplary descriptions such as "in some embodiments (or examples)" and "in one embodiment (or example)" may include but are not limited to the following meanings: these solutions can be combined with other solutions in a suitable manner to form new technical solutions.

[0145] In this application, unless otherwise specified, the "solid-state battery" provided in this application refers to a battery in which the electrolyte in the battery includes a solid electrolyte; generally, a solid-state battery includes a positive electrode layer, a solid electrolyte layer and a negative electrode layer. During the charge and discharge process of the battery, active ions are embedded and released back and forth between the positive electrode layer and the negative electrode layer. The solid electrolyte layer plays the role of conducting ions between the positive electrode layer and the negative electrode layer, and can also isolate the positive electrode layer from the negative electrode layer to prevent the positive and negative electrodes from short-circuiting. Therefore, the isolation membrane in the traditional lithium-ion battery can be omitted in the solid-state battery. The solid-state battery uses a non-flammable solid electrolyte to replace the organic electrolyte in the traditional liquid lithium-ion battery, which greatly improves the safety of the battery. In addition to improving safety, solid-state batteries can better adapt to high-energy-density positive and negative electrode materials and reduce the weight of the system, which is conducive to taking into account the improvement of energy density.

[0146] In this application, unless otherwise specified, "solid electrolyte" refers to an electrolyte material or substance that exists in a solid form during the storage and preparation of a solid-state battery and its components, as well as during the operation of the solid-state battery. It is understood that the solid electrolyte exists in a solid form, including but not limited to, at room temperature.

[0147] In the present application, unless otherwise specified, the electrode layer may be a positive electrode layer or a negative electrode layer, and the "active material" in the electrode layer refers to a substance that can reversibly embed and release active ions. Unless otherwise specified, "negative electrode active material" refers to a substance used in the negative electrode layer that can reversibly embed and release active ions; "positive electrode active material" refers to a substance used in the positive electrode layer that can reversibly release and embed active ions. When the solid-state battery is charging, the active ions are released from the positive electrode and embedded in the negative electrode through the solid electrolyte layer; when the solid-state battery is discharging, the active ions are released from the negative electrode and embedded in the positive electrode. There is no special limitation on the active ions. Non-restrictively, the active ions can be lithium ions, which corresponds to a lithium-ion solid-state battery.

[0148] In this application, "electrode active material", "electrode active substance", "active material" and "active substance" have the same meaning and can be used interchangeably; "positive electrode active substance" and "positive electrode active material" have the same meaning and can be used interchangeably; "negative electrode active substance" and "negative electrode active material" have the same meaning and can be used interchangeably. "Positive electrode active substance" and "positive electrode active material" have the same meaning and can be used interchangeably; "negative electrode active substance" and "negative electrode active material" have the same meaning and can be used interchangeably.

[0149] In this application, unless otherwise specified, the term "electrode active material layer" includes at least one of the positive electrode active material layer in the positive electrode layer and the negative electrode active material layer in the negative electrode layer. Depending on the specific circumstances, the electrode active material layer may refer to the positive electrode active material layer or the negative electrode active material layer. It is understood that the positive electrode active material layer contains a positive electrode active substance, and the negative electrode active material layer contains a negative electrode active substance. In this application, the term "electrode active material layer" may also be referred to as the "active material layer."

[0150] In the present application, unless otherwise specified, the positive electrode layer at least includes a positive electrode active material layer.

[0151] In the present application, unless otherwise specified, the positive electrode active material layer includes at least positive electrode active particles and generally also includes positive electrode electrolyte particles.

[0152] In this application, unless otherwise specified, “positive electrode active particles” refer to particles containing positive electrode active materials, which have the ability to reversibly release and embed active ions.

[0153] In this application, unless otherwise specified, "positive electrode electrolyte particles" and "positive electrode solid electrolyte" have the same meaning and can be used interchangeably to refer to solid electrolytes that can be used in positive electrode membranes or positive electrode layers. Positive electrode electrolyte particles can enhance the ion conductivity of the positive electrode membrane or positive electrode layer and reduce interfacial impedance, thereby promoting the charge transfer efficiency between the positive electrode active material and the outside world and fully releasing its capacity.

[0154] In this application, unless otherwise specified, “negative electrode active particles” refer to particles containing negative electrode active materials, which have the ability to reversibly embed and de-embed active ions.

[0155] In solid-state batteries, the interface contact problem is one of the pain points that limits its performance. Poor interface contact will affect the discharge capacity of the battery and will also deteriorate the rate performance and cycle performance of the battery. At present, the common practice for solid-state batteries is to adopt a composite positive electrode mode on the positive electrode side of the solid-state battery, and to set positive electrode active materials and solid electrolytes in the positive electrode at the same time. The solid electrolyte is used to enhance the ion conductivity of the positive electrode side, promote the charge transfer efficiency between the positive electrode active material and the outside world and the full release of its capacity, and reduce the impedance; at the same time, the electronic conductivity of the positive electrode active material itself is used to conduct electrons to improve the cycle stability of the battery. Among the many solid electrolyte materials, sulfide solid electrolytes have an ultra-high ionic conductivity (about 10 -3 ~10 -2 S / cm, almost the same as commercial liquid electrolytes) and good flexibility, giving it excellent ion conductivity and good deformation ability, making it a solid electrolyte material with the most practical and industrial prospects.

[0156] However, due to the "solid-solid contact" characteristics of solid-state batteries, the contact between the positive electrode active material and the solid electrolyte includes a large number of point contacts, which cannot completely wet the positive electrode active material like the electrolyte in liquid batteries. This results in insufficient interfacial ion transport between the positive electrode active material and the solid electrolyte, which in turn leads to suboptimal solid-state battery performance. In sulfide solid-state batteries containing sulfide electrolytes, especially sulfide solid-state batteries containing sulfide electrolytes in the positive electrode active material layer, interfacial ion transport between the positive electrode active material and the sulfide electrolyte is one of the key factors affecting battery performance.

[0157] For sulfide solid-state batteries that include oxide positive active materials in the positive electrode active material layer, the interfacial side reactions between the oxide positive active material and the sulfide electrolyte are also one of the key factors that restrict battery performance. The interfacial side reactions involved include chemical reactions in direct contact between the oxide and the sulfide, as well as electrochemical reactions caused by the oxidation and decomposition of the sulfide electrolyte due to the release of oxygen by the oxide positive active material at high voltage. Lithium transition metal oxides are one of the commonly used positive electrode active materials in traditional lithium-ion secondary batteries and can provide good energy density. When oxide positive electrode active materials (such as lithium transition metal oxides) are used in the positive electrode of all-solid-state batteries, the electrochemical operating window of the positive electrode is usually between 2.8V and 4.8V. For example, the electrochemical operating window of positive electrodes using lithium cobalt oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium-rich manganese positive active materials, etc. as positive electrode active materials is usually within the aforementioned range. However, under high voltage, oxide positive electrode active materials (such as lithium transition metal oxides) easily release oxygen, which affects the stability of the positive electrode active material and deteriorates the battery cycle performance. For a positive electrode comprising a sulfide solid electrolyte, when the positive electrode active material includes an oxide positive electrode active material (such as a lithium transition metal oxide), since the electrochemical operating window has a relatively high voltage, the sulfide solid electrolyte is easily oxidized and decomposed at this high voltage, which can easily cause deterioration of the discharge capacity, rate performance and cycle performance.

[0158] If the surface of the positive electrode active material is coated with electrolyte materials such as LiNbO3, LiTaO3, Li3BO3, Li2ZrO3, etc., it can theoretically play a role in blocking the chemical reaction between the oxide positive electrode active material and the sulfide electrolyte. However, it cannot inhibit the oxygen release of the oxide positive electrode active material. Moreover, this type of coating material has the characteristics of ion conduction and electronic insulation, and the ion conductivity is also low (such as 10 -5 S / cm), which can easily lead to insufficient electron conduction at the positive electrode, and then lead to insufficient interface ion conduction and electron conduction of the solid-state battery, resulting in unsatisfactory discharge capacity, rate performance and cycle performance of the battery at high voltage.

[0159] Based on this, according to various embodiments and examples of the present application, the embodiments and examples of the present application provide at least one positive electrode active layer composition, positive electrode active coated particles, positive electrode film, solid-state battery, electrical device and application.

[0160] In a first aspect of the present application, a positive electrode active layer composition is provided.

[0161] In some embodiments, a positive electrode active layer composition is provided, which includes positive electrode active coating particles and positive electrode electrolyte particles; the positive electrode active coating particles include a positive electrode active body and a first coating sublayer and a second coating sublayer coated on at least a portion of the surface of the positive electrode active body, and the first coating sublayer is located between the positive electrode active body and the second coating sublayer; the positive electrode active body includes an oxide positive electrode active material; the first coating sublayer includes a non-carbon conductive material; the second coating sublayer includes an electrolyte solid; at least one of the positive electrode electrolyte particles and the second coating sublayer contains a sulfide electrolyte.

[0162] In some embodiments, a positive electrode active layer composition is provided, which includes positive electrode active coated particles and positive electrode electrolyte particles; the positive electrode active coated particles include a positive electrode active body and a coating layer coated on at least a portion of the surface of the positive electrode active body, the coating layer includes a first coating sublayer and a second coating sublayer, and the second coating sublayer is located on the surface of the side of the first coating sublayer away from the positive electrode active body (that is, the coating layer includes the second coating sublayer and the first coating sublayer located between the positive electrode active body and the second coating sublayer); the positive electrode active body includes an oxide positive electrode active material; the first coating sublayer includes a non-carbon conductive material (for example, the non-carbon conductive material may include at least one of Se element, Te element and Se / Te complex); the second coating sublayer includes an electrolyte solid; at least one of the positive electrode electrolyte particles and the second coating sublayer contains a sulfide electrolyte.

[0163] The positive electrode active layer composition can be used to form a positive electrode active material layer. A solid-state battery prepared using the positive electrode active layer composition can have good discharge capacity, rate capability, and cycle performance. The positive electrode active material layer can be located in the positive electrode film or in the positive electrode layer included in the solid-state battery.

[0164] In some embodiments, a positive electrode active layer composition is provided, which includes positive electrode active coating particles and positive electrode electrolyte particles;

[0165] The positive electrode active coated particles include a positive electrode active body and a coating layer coated on at least a portion of the surface of the positive electrode active body, the coating layer includes a first coating sublayer and a second coating sublayer, and the second coating sublayer is located on a side of the first coating sublayer away from the positive electrode active body;

[0166] The positive electrode active body includes a positive electrode active material, and the positive electrode active material includes an oxide positive electrode active material;

[0167] The first coating sublayer includes a non-carbon conductive material, wherein the non-carbon conductive material may include at least one of a Se element, a Te element, and a Se / Te complex, wherein the chemical formula of the Se / Te complex is Se x Te 1-x, 0 <x<1;

[0168] The second coating sublayer includes electrolyte solids;

[0169] At least one of the positive electrode electrolyte particles and the second coating sublayer includes a sulfide electrolyte.

[0170] In this application, unless otherwise stated, a "composition" is a mixture of a plurality of different substances.

[0171] In this application, unless otherwise specified, a "positive electrode active layer composition" refers to a mixture that can be used to prepare a positive electrode active material layer. It is understood that because at least one of the positive electrode electrolyte particles and the second coating sublayer of the positive electrode active coating particles contains a sulfide electrolyte, a solid-state battery in which the positive electrode layer includes the positive electrode active layer composition is a sulfide solid-state battery.

[0172] Unless otherwise specified, a "sulfide solid-state battery" refers to a solid-state battery in which the electrolyte involved in the battery includes a sulfide-based solid electrolyte. For example, the sulfide-based solid electrolyte can be located in the cathode layer of the sulfide solid-state battery, or in the solid electrolyte layer. Sulfide solid-state batteries can further be all-solid-state batteries.

[0173] In this application, unless otherwise specified, "all-solid-state battery" refers to a solid-state battery in which the electrolytes in the battery are all solid electrolytes. In this case, the positive electrode layer, the negative electrode layer and the electrolyte part are all made of solid materials, and no liquid electrolyte is provided in the battery, so it can be called an "all-solid-state battery".

[0174] In this application, unless otherwise specified, a "solid-state battery" in any embodiment or example may be, but is not limited to, a sulfide all-solid-state battery. Unless otherwise specified, a "sulfide all-solid-state battery" refers to an all-solid-state battery in which the electrolyte involved in the battery includes a sulfide-based solid electrolyte. The sulfide-based solid electrolyte can be located in the positive electrode layer of the sulfide all-solid-state battery or in the solid electrolyte layer.

[0175] In this application, unless otherwise specified, "sulfide electrolyte", "sulfide electrolyte component" and "sulfide solid electrolyte component" have the same meaning and can be used interchangeably, referring to a solid electrolyte component in the form of a sulfide. The chemical formula of the sulfide electrolyte includes a sulfide composed of the element sulfur (S). The "sulfide electrolyte" involved in the embodiments or examples of this application is not particularly limited in its form. It can be an independent sulfide electrolyte substance or a part of a composite material. For example, it can be a sulfide electrolyte component in the positive electrode electrolyte particles, or it can be a sulfide electrolyte component located in the positive electrode active coating particles (in this case, the second coating sublayer of the positive electrode active coating particles contains a sulfide electrolyte), or it can be a sulfide electrolyte component in the solid electrolyte layer.

[0176] In this application, unless otherwise specified, "sulfide-based electrolyte", "sulfide-based solid electrolyte" and "sulfide-based electrolyte particles" have the same meaning and can be used interchangeably, referring to a solid electrolyte containing a sulfide electrolyte component, which may be the sulfide electrolyte itself, but is not limited to this.

[0177] In this application, unless otherwise specified, the types of sulfide electrolyte components contained in different locations or different materials of the "sulfide solid-state battery" may be the same or different. For example, the types of sulfide electrolyte components contained in the positive electrode layer and the solid electrolyte layer may be the same or different. The types of sulfide electrolyte components in the positive electrode active coating particles and the sulfide electrolyte components in the sulfide-based electrolyte may also be the same or different. For example, the sulfide-based electrolyte component may be located in the positive electrode electrolyte particles or in the solid electrolyte layer, but is not limited thereto.

[0178] In this application, unless otherwise specified, "solid electrolyte" refers to an electrolyte material or substance that exists in a solid form and is a type of solid electrolyte.

[0179] In this application, unless otherwise specified, a "positive electrode active coated particle" includes a positive electrode active body and a coating layer coated on at least a portion of the surface of the positive electrode active body. The coating layer includes a first coating sublayer and a second coating sublayer, that is, includes at least two coating sublayers. Therefore, the positive electrode active coated particle has a multi-layer coating structure. In this application, the "coating layer" or "coating sublayer" in the positive electrode active coated particle, unless otherwise specified, can be located on a portion of the surface of the positive electrode active body, or can completely coat the positive electrode active body.

[0180] In the present application, the positive electrode active body includes positive electrode active materials. Unless otherwise specified, the positive electrode active materials included in the positive electrode active coated particles include oxide positive electrode active materials. In the present application, unless otherwise specified, the "oxide positive electrode active material" has the well-known meaning in the art and refers to the positive electrode active material in the form of an oxide. Non-limiting examples of the oxide positive electrode active material include lithium transition metal oxides.

[0181] In the present application, unless otherwise specified, the "lithium transition metal oxide" has the well-known meaning in the art and refers to the positive electrode active material containing transition metal elements and lithium elements.

[0182] In the present application, unless otherwise specified, the "non-carbon conductive material" refers to a conductive material that is different from the carbon conductive material and has the ability of electron conduction. Unless otherwise specified, the "carbon conductive material" refers to a conductive material composed of carbon elements, such as traditional carbon conductive agents, and further such as one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0183] In the present application, the "non-carbon conductive material" in the positive electrode active layer composition includes a first conductive material; in the present application, the "first conductive material" is at least one of Se单质, Te单质, and Se / Te composite, and the chemical formula of the Se / Te composite is Se x Te 1-x , 0 < x < 1. Non-limitingly, x can be any one of the following values or a range selected from any two of the following values: 0.01, 0.02, 0.04, 0.05, 0.06, 0.08, 0.1, 0.12, 0.14, 0.15, 0.16, 0.18, 0.2, 0.22, 0.24, 0.25, 0.26, 0.28, 0.3, 0.32, 0.35, 0.36, 0.38, 0.4, 0.42, 0.44, 0.45, 0.46, 0.48, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.92, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, etc. Among them, both Se单质 and Te单质 have relatively high electron conductivities. The electron conductivity of Se单质 is about 10 mS / cm, and the electron conductivity of Te单质 is about 2000 mS / cm. In addition, within the electrochemical window of 2.8 V to 4.8 V, for example, within the electrochemical working window of the oxide positive electrode active material (such as lithium transition metal oxide), selenium (Se) and tellurium (Te) have almost no electrochemical activity and can basically not participate in the electrochemical reaction, and can be basically regarded as not contributing capacity. At this time, the capacity is provided by the positive electrode active materials such as the oxide positive electrode active material (such as lithium transition metal oxide).

[0184] In this application, unless otherwise specified, "Se单质" and "单质Se" have the same meaning and can be used interchangeably, both representing Se in elemental form. Unless otherwise specified, "Te单质" and "单质Te" have the same meaning and can be used interchangeably, both representing Te in elemental form.

[0185] In this application, unless otherwise specified, "Se / Te composite" refers to a substance composed of Se element and Te element, with the chemical formula Se x Te 1-x (0 < x < 1), which can also be denoted as "selenium tellurium alloy". Generally, the following method can be used to prepare Se / Te composites with a specific atomic ratio: Weigh Se powder and Te powder according to the stoichiometric ratio, vacuum-seal them in a quartz tube with a vacuum degree of about 10 -5 Torr, then heat to obtain a uniformly mixed melt at 900 °C, and quench the melt in ice water to obtain the Se / Te composite (selenium tellurium alloy).

[0186] In this application, the non-carbon conductive material in the positive electrode active layer composition may include other types of non-carbon conductive materials in addition to the first conductive material, such as non-carbon conductive materials with an electronic conductivity greater than or equal to that of Se单质 under certain temperature conditions. Non-limiting examples of other types of non-carbon conductive materials are non-carbon conductive materials with an electronic conductivity greater than or equal to that of Se单质 at at least one temperature or within at least one temperature range from 20 °C to 一百 °C under the same test conditions.

[0187] For solid-state batteries with a relatively low voltage in the electrochemical window, Se单质 and Te单质 are used as positive electrode active materials in the positive electrode of the solid-state battery. At this time, Se单质 and Te单质 can undergo conversion reactions to store lithium; for example, the electrochemical working window of a lithium-ion solid-state battery using selenium as the positive electrode active material (which can be denoted as a lithium-selenium battery) is approximately between 1.0 V and 3.0 V.

[0188] It should be noted that there is an unclear symbol "一百" in the original text. It might be a mistake. If this is a specific value that needs to be accurately translated, please correct it and let me know for a more accurate translation.The positive electrode active layer composition includes positive electrode active coated particles having a multi-layer coating structure and positive electrode electrolyte particles, wherein the inner core of the positive electrode active coated particles is a positive electrode active body containing an oxide positive electrode active material (such as a lithium transition metal oxide), and a first coating sublayer containing a non-carbon conductive material and a second coating sublayer containing an electrolyte solid are sequentially arranged on the surface of the positive electrode active body, and at least one of the positive electrode electrolyte particles and the second coating sublayer contains a sulfide electrolyte component, that is, the oxide positive electrode active material (such as a lithium transition metal oxide) in the positive electrode active coated particles is separated from the sulfide electrolyte contained in the positive electrode active layer composition by at least the first coating sublayer, and the sulfide electrolyte contained in the positive electrode active layer composition can be located in the positive electrode electrolyte particles or in the second coating sublayer of the positive electrode active coated particles.

[0189] The non-carbon conductive material in the first coating sublayer includes a first conductive material, which is at least one of a single substance of Se, a single substance of Te, and a Se / Te complex, and is composed of one or both of selenium (Se) and tellurium (Te). Se and Te both have high electronic conductivity, with the electronic conductivity of Se being approximately 10 mS / cm and that of Te being approximately 2000 mS / cm. This allows the non-carbon conductive material to provide good electronic conductivity and can be used in the positive electrode film or the positive electrode layer of a solid-state battery. Within the electrochemical operating window (e.g., 2.8 V to 4.8 V) of the oxide positive electrode active material (e.g., lithium transition metal oxide), selenium (Se) and tellurium (Te) have almost no electrochemical activity, contribute little to the capacity, and can basically not participate in the electrochemical reaction, thereby maintaining stable electronic conductivity. In addition, Se and Te are elements in the same main group as sulfur (S), and have good compatibility with sulfide electrolytes.

[0190] By utilizing the isolation effect of the first conductive material in the first coating sublayer on the oxide positive electrode active material (such as lithium transition metal oxide) and the sulfide electrolyte, the direct contact and interface side reactions between the oxide positive electrode active material (such as lithium transition metal oxide) and the sulfide electrolyte can be reduced or blocked. The superoxide ions (O2 2- ) or oxygen radicals can react with Se and / or Te in non-carbon conductive materials to generate SeO3 2- and / or TeO3 2- This reaction can inhibit the release of oxygen from oxide positive electrode active materials (such as lithium transition metal oxides), reduce the oxidative decomposition of sulfide electrolytes, improve the structural stability of positive electrode active particles and the electrochemical performance of the battery, and the prepared solid-state battery can have high discharge capacity, high rate performance and good cycle performance at the same time.

[0191] A second coating sublayer is further provided in the positive electrode active particles provided with the first coating sublayer. The ion conductivity provided by the electrolyte solid in the second coating sublayer can be utilized to enhance the interface contact between the positive electrode active material and the positive electrode electrolyte particles, thereby enhancing the ion conduction between the positive electrode active coating particles and the positive electrode electrolyte particles, reducing the interface impedance, and improving the battery performance.

[0192] The first coating sublayer can provide higher electronic conductivity, and the electrolyte solid in the second coating sublayer can improve the ion transmission capacity, so that the positive electrode active layer composition has both higher electronic conductivity and good ion conductivity. This structural design can also simultaneously inhibit the release of oxygen by the oxide positive electrode active material (such as lithium transition metal oxide), which can give the corresponding solid-state battery higher discharge capacity and rate performance, and can improve the cycle performance of the solid-state battery.

[0193] By utilizing the multiple synergistic effects between solid-state positive electrode coating particles and positive electrode electrolyte particles, a good and stable electrical contact network can be formed in the positive electrode active material layer, reducing the interfacial impedance, promoting the charge transfer efficiency between the positive electrode active material and the outside world and the full release of its capacity, and can be used to prepare solid-state batteries with high discharge capacity, high rate performance and good cycle performance.

[0194] The structure of the positive electrode active coated particles 80 in some embodiments of the present application can be seen in Figures 1 and 2. The positive electrode active coated particles 80 shown in Figure 1 include a positive electrode active body 82 and a first coating sublayer 84 and a second coating sublayer 86 located on the surface of the positive electrode active body 82. The second coating sublayer 86 is located on the side of the first coating sublayer 84 away from the positive electrode active body 82, that is, the first coating sublayer 84 is located between the positive electrode active body 82 and the second coating sublayer 86. The positive electrode active coated particles 80 shown in Figure 2 include a positive electrode active body 82 and a first coating sublayer 84 and a second coating sublayer 86 located on the surface of the positive electrode active body 82. The first coating sublayer 84 is located between the positive electrode active body 82 and the second coating sublayer 86. The positive electrode active body 82 includes an oxide positive electrode active material 802, the first coating sublayer 84 includes a non-carbon conductive material 804, and the second coating sublayer 86 includes an electrolyte solid material 806.

[0195] In some embodiments of the present application, the positive electrode active layer composition includes, but is not limited to, positive electrode active coated particles 80a whose second coating sublayer comprises a sulfide electrolyte, and positive electrode electrolyte particles 66, wherein the second coating sublayer of the positive electrode active coated particles comprises a sulfide electrolyte. See FIG3 for a schematic diagram of the composition of the positive electrode active layer composition that can be used to prepare the positive electrode active material layer 220.

[0196] In some embodiments of the present application, the positive electrode active layer composition includes but is not limited to positive electrode active coating particles 80 and sulfide-based electrolyte 662. A schematic diagram of the composition of the positive electrode active layer composition that can be used to prepare the positive electrode active material layer 220 is shown in FIG4 .

[0197] In some embodiments of the present application, the positive electrode active layer composition includes, but is not limited to, positive electrode active coated particles 80a whose second coating sublayer comprises a sulfide electrolyte, and a sulfide-based electrolyte 662. The second coating sublayer of the positive electrode active coated particles comprises a sulfide electrolyte, and the sulfide-based electrolyte 662 also comprises a sulfide electrolyte. See FIG5 for a schematic diagram of the composition of the positive electrode active layer composition that can be used to prepare the positive electrode active material layer 220.

[0198] In some embodiments of the present application, the positive electrode active layer composition includes, but is not limited to, positive electrode active coated particles 80a having a second coating sublayer comprising a sulfide electrolyte, wherein the second coating sublayer of the positive electrode active coated particles comprises a sulfide electrolyte. See FIG6 for a schematic diagram of the composition of a positive electrode active layer composition that can be used to prepare the positive electrode active material layer 220.

[0199] It can be understood that the components of each positive electrode active material layer shown in FIG. 3 , FIG. 4 , FIG. 5 and FIG. 6 may be independently not limited to those shown in the figures.

[0200] The structure of the positive electrode active coated particle 80 in some embodiments of the present application can be seen in FIG7 . In the positive electrode active coated particle 80a shown in FIG7 , in which the second coating sublayer includes a sulfide electrolyte, the positive electrode active body 82 includes an oxide positive electrode active material 802 , the first coating sublayer 84 includes a non-carbon conductive material 804 , and the second coating sublayer 86 includes a sulfide-based electrolyte 662 (in this case, the electrolyte solid material 806 includes the sulfide-based electrolyte 662 ).

[0201] Those skilled in the art will appreciate that, based on the structure and chemical composition of the positive electrode active coated particles described herein, they can be prepared using, but are not limited to, existing particle coating methods. As a non-limiting example, a physical coating method can be used. A solid coating material can be coated onto at least a portion of the surface of the target particulate matter using an existing physical coating method. Dry coating can be employed, but is not limited thereto. See also the Examples below.

[0202] In one aspect of the present application, a method for preparing positive electrode active coated particles is provided, comprising the following steps:

[0203] S100: providing a first coating sublayer comprising a non-carbon conductive material on at least a portion of the surface of the positive electrode active body to obtain a first coating intermediate; and

[0204] S200: Disposing a second coating sublayer including an electrolyte solid material on at least a portion of the surface of the first coating sublayer away from the positive electrode active body.

[0205] In the positive electrode active coated particles of the embodiment or example of the present application, the second coating sublayer may or may not contain a sulfide electrolyte.

[0206] In some embodiments, a first coating sublayer including a non-carbon conductive material is provided on at least a portion of the surface of the positive electrode active body by dry coating technology (which can be performed using dry coating equipment). In some embodiments, according to the target coating amount of the non-carbon conductive material, the positive electrode active body and the first coating sublayer material including the non-carbon conductive material are mixed in a desired proportion, and heat treated in an inert atmosphere (such as an argon atmosphere) to obtain a first coated intermediate, which includes the positive electrode active body and the first coating sublayer located on at least a portion of the surface of the positive electrode active body, wherein the first coating sublayer includes a non-carbon conductive material. 0.8 Co 0.1 Mn 0.1 Taking O2 as the positive electrode active entity and Se as the first coating sublayer as an example, it can be heat-treated at 300°C in an argon atmosphere for 1 hour, and the corresponding first coating intermediate can be recorded as "NCM811@Se coating body".

[0207] In some embodiments, a second coating sublayer is introduced on the basis of the first coating intermediate by a wet coating technique, and the second coating sublayer including the electrolyte solid is arranged on at least a portion of the surface of the first coating sublayer away from the positive electrode active body. In some embodiments, the second coating sublayer material including the electrolyte solid is mixed with a dispersion solvent (such as uniformly mixed by stirring), added to the first coating intermediate, dispersed (such as dispersed by stirring), and the resulting dispersion is dried under heating conditions to obtain positive electrode active coated particles having both the first coating sublayer and the second coating sublayer. The dispersion solvent can be a non-aqueous solvent, and can further be an anhydrous organic solvent. The first coating intermediate is the "NCM811@Se coating body", and Li 5.5 PS 4.5 Cl 1.5 (which can be recorded as LPSCl) sulfide electrolyte constitutes the second coating sublayer as an example, the dispersion solvent can be anhydrous acetonitrile, 5.5 PS 4.5 Cl 1.5(LPSCl) was stirred and mixed with anhydrous acetonitrile, and a measured amount of NCM811@Se coating was added according to the coating amount of the second coating sublayer, and stirring was continued for 3 hours. The obtained dispersion was vacuum dried at 150°C for 5 hours to remove the liquid phase solvent. Then, positive electrode active coating particles with Se as the first coating sublayer and LPSCl as the second coating sublayer were obtained, which can be recorded as "NCM811@Se@LPSCl coating".

[0208] In this application, particle structure analysis methods such as transmission electron microscopy (TEM) can be used to detect and analyze whether the particles have a coating layer. Elemental analysis methods such as energy dispersive spectrometer (EDS), X-ray diffraction (XRD) technology, and inductively coupled plasma spectrometer (ICP method) can also be combined to detect and identify the element types and chemical composition of the positive electrode active body, coating layer, and each coating sublayer. These methods can also be used to analyze parameters such as the thickness of the coating layer and each coating sublayer, the weight proportion or weight percentage of the coating layer and each coating sublayer in the positive electrode active coated particles.

[0209] It should be noted that the positive electrode active layer composition described in this application can be directly introduced into the preparation process of solid-state batteries, sulfide batteries or sulfide all-solid-state batteries in solid form by a dry method, and can also be introduced into the battery preparation process in the form of a slurry by a wet method, and then the solvent is removed by a subsequent drying process, leaving only the solid material in the slurry in the battery.

[0210] In some embodiments, the positive electrode active layer composition is a solid material, and its constituent materials are all solid.

[0211] In some embodiments, the positive electrode active layer composition is a slurry composed of a solid material and a dispersing solvent. It is understood that the solid material in the slurry includes at least the aforementioned positive electrode active coating particles and positive electrode electrolyte particles. Typically, the dispersing solvent is a non-aqueous solvent. As non-limiting examples, the removable solvent may include one or more of p-xylene, trimethylbenzene, butyl butyrate, heptane, and the like, and may further include p-xylene.

[0212] In some embodiments, the cathode active layer composition is applied to a cathode film or a cathode layer in a solid-state battery.

[0213] In some embodiments, the electronic conductivity of the non-carbon conductive material at at least one temperature between 20°C and 100°C or at least a portion of the temperature range is greater than or equal to that of a single substance of Se. Without limitation, the temperature at which the electronic conductivity is tested may be any of the following temperatures or an interval consisting of any two of the following temperatures: 20°C, 25°C, 26°C, 30°C, 35°C, 40°C, 45°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, etc. As a non-limiting example, the temperature at which the electronic conductivity is tested may also be 20°C to 30°C, 20°C to 40°C, 20°C to 50°C, 20°C to 60°C, 20°C to 80°C, 40°C to 50°C, 40°C to 60°C, etc.

[0214] The non-carbon conductive material in the first coating sublayer may include, in addition to the first conductive agent, other non-carbon conductive materials with good electronic conductivity. For example, the other non-carbon conductive materials may be non-carbon conductive materials whose electronic conductivity is better than that of Se elemental substance or substantially equivalent to that of Se elemental substance under certain temperature conditions.

[0215] In this application, unless otherwise specified, the electronic conductivity of non-carbon conductive materials may be tested using conventional methods for testing powdered conductive agents, such as a four-probe tester.

[0216] In some embodiments, the weight percentage of the Te element in the non-carbon conductive material is ≥0 wt % (i.e., greater than or equal to 0 wt %), optionally ≥50 wt %, further optionally 50 wt % to 100 wt %, and further optionally 60 wt % to 100 wt %. The weight percentage of the Te element in the non-carbon conductive material can also be any of the following percentages, or a range consisting of any two of the following percentages: 0 wt %, 10 wt %, 20 wt %, 30 wt %, 40 wt %, 50 wt %, 60 wt %, 70 wt %, 80 wt %, 90 wt %, 100 wt %, etc.

[0217] Te has a high electronic conductivity (approximately 2000mS / cm), which is roughly the same order of magnitude as that of traditional carbon black materials (for example, carbon black has an electronic conductivity of approximately 10S / cm to 100S / cm), providing excellent electronic conductivity. By adding a higher proportion of Te to non-carbon conductive materials, it is beneficial to prepare solid-state batteries with higher discharge capacity, higher rate performance, and better cycle performance.

[0218] In some embodiments, the weight percentage of the first conductive material in the non-carbon conductive material can be 80wt% to 100wt%, optionally 90wt% to 100wt%, or any of the following percentages or an interval consisting of any two of the following percentages: 80wt%, 85wt%, 90wt%, 95wt%, 96wt%, 98wt%, 99wt%, 99.9wt%, 100wt%, etc.

[0219] In some embodiments, the non-carbon conductive material is the first conductive material, that is, it is composed of the first conductive material. In this case, the weight percentage of the first conductive material in the non-carbon conductive material is 100wt%, and the non-carbon conductive material is at least one of Se elemental substance, Te elemental substance and Se / Te complex, and the chemical formula of the Se / Te complex is Se x Te 1-x , 0 <x<1。

[0220] By controlling the weight percentage of the first conductive material in the non-carbon conductive material within the aforementioned range, the first conductive material can better play the role of inhibiting the release of oxygen from the oxide positive electrode active material (such as lithium transition metal oxide), which is conducive to preparing a solid-state battery with higher discharge capacity, higher rate performance and better cycle performance.

[0221] In some embodiments, the D of the non-carbon conductive material v 50 can be 1nm~1μm, optionally 10nm~1μm, further optionally 10nm~500nm, but not limited thereto; wherein, D v 50 represents the particle size corresponding to the cumulative volume distribution percentage of the multi-particle mixture reaching 50%. v 50 can also be any of the following particle sizes or an interval consisting of any two of the following particle sizes: 1nm, 5nm, 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 80nm, 100nm, 0.1μm, 150nm, 0.15μm, 0.2μm, 0.3μm, 0.4μm, 0.5μm, etc.

[0222] D v The definition and test method of 50 can also be found in the corresponding description in the context.

[0223] By controlling the particle size of the non-carbon conductive material within the above range, it is beneficial to fully utilize the function of the first coating sublayer while taking into account the manufacturing cost. A relatively moderate particle size of the non-carbon conductive material is easier to manufacture.

[0224] In some embodiments, the weight percentage of the first coating sublayer in the positive electrode active coating particles is 0.1 wt % to 10 wt %, and can be optionally 0.5 wt % to 5 wt %. Without limitation, the weight percentage of the first coating sublayer in the positive electrode active coating particles can also be any of the following percentages or an interval consisting of any two of the following percentages: 0.1 wt %, 0.2 wt %, 0.4 wt %, 0.5 wt %, 0.6 wt %, 0.8 wt %, 1 wt %, 1.2 wt %, 1.5 wt %, 1.6 wt %, 1.8 wt %, 2 wt %, 2.5 wt %, 3 wt %, 3.5 wt %, 4 wt %, 5 wt %, 6 wt %, 7 wt %, 7.5 wt %, 8 wt %, 8.5 wt %, 9 wt %, 9.5 wt %, 10 wt %, etc.

[0225] In some embodiments, the weight percentage of the non-carbon conductive material in the first coating sublayer may be, but is not limited to, 80 wt% to 100 wt%, optionally 90 wt% to 100 wt%, or any of the following percentages, or a range consisting of any two of the following percentages: 80 wt%, 85 wt%, 90 wt%, 95 wt%, 96 wt%, 98 wt%, 99 wt%, 99.9 wt%, 100 wt%, etc. Without limitation, the non-carbon conductive material may be the first conductive material.

[0226] In some embodiments, the weight percentage of the non-carbon conductive material in the positive electrode active coating particles can also be any of the following percentages or an interval consisting of any two of the following percentages: 0.1 wt%, 0.2 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.8 wt%, 1 wt%, 1.2 wt%, 1.5 wt%, 1.6 wt%, 1.8 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 7.5 wt%, 8 wt%, 8.5 wt%, 9 wt%, 9.5 wt%, 10 wt%, etc. Without limitation, the non-carbon conductive material can be the first conductive material.

[0227] In some embodiments, the thickness of the first cladding sublayer is 0.1 nm to 50 nm, optionally 0.5 nm to 10 nm. In a non-limiting manner, the thickness of the first cladding sublayer can be any of the following thicknesses or an interval consisting of any two of the following thicknesses: 0.1 nm, 0.2 nm, 0.3 nm, 0.4 nm, 0.5 nm, 0.6 nm, 0.8 nm, 0.9 nm, 1 nm, 1.2 nm, 1.5 nm, 1.6 nm, 1.8 nm, 2 nm, 2.5 nm, 3 nm, 3.5 nm, 4 nm, 5 nm, 6 nm, 7 nm, 7.5 nm, 8 nm, 8.5 nm, 9 nm, 9.5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, etc.

[0228] In some embodiments, the positive electrode active coated particles meet one or more of the following characteristics (any numerical parameter in the following characteristics can also be selected from any appropriate value or range in the context):

[0229] The weight percentage of the first coating sublayer in the positive electrode active coating particles can be 0.1wt% to 10wt%, and can be optionally 0.5wt% to 5wt%;

[0230] The weight percentage of the non-carbon conductive material in the first coating sublayer may be 80 wt% to 100 wt%; optionally 90 wt% to 100 wt%;

[0231] The thickness of the first cladding sublayer may be 0.1 nm to 50 nm, and may be optionally 0.5 nm to 10 nm.

[0232] By adjusting at least one of the parameters of the weight percentage of the first coating sublayer in the positive electrode active coating particles, the weight percentage of the non-carbon conductive material in the first coating sublayer and the thickness of the first coating sublayer within the aforementioned range, it is more conducive to forming a good and stable electrical contact network and reducing the interface impedance while also improving the structural stability of the positive electrode active material, which is more conducive to enabling solid-state batteries to achieve higher discharge capacity, higher rate performance and better cycle performance.

[0233] In some embodiments, in the positive electrode active layer composition, the sulfide electrolyte may include, but is not limited to, one or more of an argyrodite-type sulfide electrolyte, an LGPS-type sulfide electrolyte, and a lithium sulfide pentasulfide diphosphorus complex-type sulfide electrolyte.

[0234] Unless otherwise specified, the argyrodite-type sulfide electrolyte has an argyrodite-type crystal structure. 6±s P 1-j A j S5±s-t B t X 1±s A sulfide electrolyte, where 0 ≤ j < 1, 0 ≤ t < 1, 0 ≤ s < 1, A can be selected from one or more elements including but not limited to Ge, Si, Sn, and Sb, B can be one or more elements among O, Se, and Te, and X can be selected from one or more elements among Cl, Br, I, and F.

[0235] Unless otherwise stated, the LGPS-based sulfide electrolyte has an LGPS-type crystal phase structure. Without limitation, the LGPS-based sulfide electrolyte can include a sulfide electrolyte with the chemical formula Li 10±δ5 Ge 1-g G g P 2-q Q q S 12-w W w A sulfide electrolyte, where 0 ≤ δ5 < 1, 0 ≤ g ≤ 1, 0 ≤ q ≤ 2, 0 ≤ w < 1, G is selected from one or two elements including Si and Sn, Q is Sb, and W is selected from one or more elements among O, Se, Te, Cl, Br, I, and F.

[0236] Without limitation, the lithium sulfide - phosphorus pentasulfide composite-based sulfide electrolyte can include a sulfide electrolyte with the chemical formula (100 - u - v)Li2S·uP2S5·vM m N n A sulfide electrolyte, where 0 < u < 100, 0 ≤ v < 100, 0 ≤ u + v < 100, 0 ≤ m < 4, 0 ≤ n < 6, M can be selected from one or more elements including but not limited to Li, B, Ge, Si, Sn, and Sb, and N can be selected from one or more elements among S, Se, Te, O, Cl, Br, I, and F.

[0237] For the case where at least one of the positive electrode electrolyte particles in the positive electrode layer of the solid-state battery and the second coating sub-layer includes the foregoing various sulfide electrolytes, the oxidation decomposition of the sulfide electrolyte at the positive electrode under high voltage can be suppressed through the multi-layer coating structure design of the positive electrode active coating particles, thereby improving the discharge capacity, rate performance, and cycle performance of the solid-state battery. In addition, the first Coulomb efficiency of the solid-state battery can also be increased.

[0238] In some embodiments, the sulfide electrolyte in the positive electrode active layer composition may include at least one of a binary sulfide solid state system and a ternary sulfide solid state system. Without limitation, the binary sulfide solid state system may include one or more of Li2S-P2S5, Li2S-SiS2, Li2S-GeS2, and Li2S-B2S3. Without limitation, the ternary sulfide solid state system may include one or more of a thiogermanite-type sulfide electrolyte, a Li2S-MeS2-P2S5 ternary sulfide electrolyte, a lithium germanium phosphorus sulfur-type sulfide electrolyte, a Li2S-P2S5-MS ternary sulfide electrolyte, a Li2S-P2S5-MCl ternary sulfide electrolyte and a thio-LISICON-type sulfide electrolyte; wherein Me may include one or more elements of silicon (Si), germanium (Ge), tin (Sn) and aluminum (Al), and may further be selected from one or more elements of Si, Ge, Sn and Al; M may include one or more elements of Ge, Al, Sn, lead (Pb), antimony (Sb), Si and arsenic (As), and may further be selected from one or more elements of Ge, Al, Sn, Pb, Sb, Si and As.

[0239] In some embodiments, the weight percentage of the second coating sublayer in the positive electrode active coating particles may be 0.1 wt % to 10 wt %, optionally 0.5 wt % to 5 wt %. Without limitation, the weight percentage of the second coating sublayer in the positive electrode active coating particles may also be any of the following percentages or an interval consisting of any two of the following percentages: 0.1 wt %, 0.2 wt %, 0.4 wt %, 0.5 wt %, 0.6 wt %, 0.8 wt %, 1 wt %, 1.2 wt %, 1.5 wt %, 1.6 wt %, 1.8 wt %, 2 wt %, 2.5 wt %, 3 wt %, 3.5 wt %, 4 wt %, 5 wt %, 6 wt %, 7 wt %, 7.5 wt %, 8 wt %, 8.5 wt %, 9 wt %, 9.5 wt %, 10 wt %, etc.

[0240] In some embodiments, the weight percentage of the electrolyte solids in the second coating sublayer may be greater than or equal to 50 wt % (i.e., ≥50 wt %), further greater than or equal to 60 wt %, further greater than or equal to 80 wt %, further greater than or equal to 90 wt %, further greater than or equal to 95 wt %, further greater than or equal to 100 wt %. The weight percentage of the electrolyte solids in the second coating sublayer may also be any of the following weight percentages or an interval selected from any two of the following weight percentages: 50 wt %, 55 wt %, 60 wt %, 65 wt %, 70 wt %, 72 wt %, 74 wt %, 75 wt %, 76 wt %, 78 wt %, 80 wt %, 82 wt %, 84 wt %, 85 wt %, 86 wt %, 88 wt %, 90 wt %, 92 wt %, 94 wt %, 95 wt %, 96 wt %, 97 wt %, 98 wt %, 99 wt %, 100 wt %, etc. Without limitation, the weight percentage of the electrolyte solids in the second coating sublayer can also be selected from any of the following ranges: 50wt% to 100wt%, 60wt% to 100wt%, 80wt% to 100wt%, 90wt% to 100wt%, etc.

[0241] In some embodiments, the weight percentage of electrolyte solids in the positive electrode electrolyte particles may be 0.1 wt % to 10 wt %, optionally 0.5 wt % to 5 wt %. Without limitation, the weight percentage of electrolyte solids in the positive electrode electrolyte particles may also be any of the following percentages or an interval consisting of any two of the following percentages: 0.1 wt %, 0.2 wt %, 0.4 wt %, 0.5 wt %, 0.6 wt %, 0.8 wt %, 1 wt %, 1.2 wt %, 1.5 wt %, 1.6 wt %, 1.8 wt %, 2 wt %, 2.5 wt %, 3 wt %, 3.5 wt %, 4 wt %, 5 wt %, 6 wt %, 7 wt %, 7.5 wt %, 8 wt %, 8.5 wt %, 9 wt %, 9.5 wt %, 10 wt %, etc.

[0242] In any relevant embodiment of the various aspects of the present application, the electrolyte solid object may be a sulfide solid electrolyte without a coating layer.

[0243] Without limitation, the weight percentage of the sulfide-based electrolyte in the electrolyte solid can be 0wt% to 100wt%, optionally 50wt% to 100wt%, further optionally 80wt% to 100wt%, further optionally 90wt% to 100wt%, or any of the following percentages or an interval consisting of any two of the following percentages: 0wt%, 1wt%, 2wt%, 4wt%, 5wt%, 6wt%, 8wt%, 10wt%, 15wt%, 20wt%, 2 5wt%, 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, 60wt%, 65wt%, 70wt%, 72wt%, 74wt%, 75wt%, 76wt%, 78wt%, 8 0wt%, 82wt%, 84wt%, 85wt%, 86wt%, 88wt%, 90wt%, 92wt%, 94wt%, 95wt%, 96wt%, 97wt%, 98wt%, 99wt%, 100wt%, etc.

[0244] In some embodiments, the electrolyte solid material includes a sulfide-based electrolyte, and the weight percentage of the sulfide-based electrolyte in the electrolyte solid material may be greater than 0 wt% and less than or equal to 100 wt%. Alternatively, the weight percentage of the sulfide-based electrolyte in the electrolyte solid material is 50 wt% to 100 wt%, further optionally 80 wt% to 100 wt%, and further optionally 90 wt% to 100 wt%.

[0245] In any relevant embodiment of the various aspects of the present application, the sulfide-based electrolyte may be a sulfide solid electrolyte without a coating layer.

[0246] In some embodiments, the thickness of the second cladding sublayer is 0.1 nm to 50 nm, optionally 0.5 nm to 10 nm. In a non-limiting manner, the thickness of the second cladding sublayer can be any of the following thicknesses or an interval consisting of any two of the following thicknesses: 0.1 nm, 0.2 nm, 0.3 nm, 0.4 nm, 0.5 nm, 0.6 nm, 0.8 nm, 0.9 nm, 1 nm, 1.2 nm, 1.5 nm, 1.6 nm, 1.8 nm, 2 nm, 2.5 nm, 3 nm, 3.5 nm, 4 nm, 5 nm, 6 nm, 7 nm, 7.5 nm, 8 nm, 8.5 nm, 9 nm, 9.5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, etc.

[0247] In some embodiments, the positive electrode active coated particles meet one or more of the following characteristics (any numerical parameter in the following characteristics can also be selected from any appropriate value or range in the context):

[0248] The weight percentage of the second coating sublayer in the positive electrode active coating particles is 0.1wt% to 10wt%, and can be optionally 0.5wt% to 5wt%;

[0249] The weight percentage of the electrolyte solid in the second coating sublayer may be 50 wt% to 100 wt%, optionally 80 wt% to 100 wt%, further optionally 90 wt% to 100 wt%;

[0250] The weight percentage of the sulfide-based electrolyte in the electrolyte solid material may be 0 wt% to 100 wt%, optionally 50 wt% to 100 wt%, further optionally 80 wt% to 100 wt%, further optionally 90 wt% to 100 wt%;

[0251] The thickness of the second cladding sublayer is 0.1 nm to 50 nm, and can be optionally 0.5 nm to 10 nm.

[0252] By adjusting at least one of the parameters of the weight percentage of the second coating sublayer in the positive electrode active coating particles, the weight percentage of the electrolyte solids in the second coating sublayer and the thickness of the second coating sublayer within the aforementioned range, it is more conducive to forming a good and stable electrical contact network while better reducing the interface impedance, and is more conducive to enabling the solid-state battery to achieve higher discharge capacity, higher rate performance and better cycle performance.

[0253] In some embodiments, both the positive electrode electrolyte particles and the second coating sublayer comprise a sulfide electrolyte.

[0254] In some embodiments, one of the cathode electrolyte particle and the second coating sublayer comprises a sulfide electrolyte and the other is an optional solid electrolyte.

[0255] In some embodiments, one of the cathode electrolyte particle and the second coating sublayer comprises a sulfide electrolyte, and the other comprises one or more of a sulfide electrolyte, a halide electrolyte, an oxide electrolyte, a polymer electrolyte, and the like.

[0256] The sulfide electrolyte can be provided in the second coating sublayer of the positive electrode active coating particles, in the positive electrode electrolyte particles, or in both locations. When a sulfide electrolyte is provided in one of the two locations, the type of solid electrolyte contained in the other location is not particularly limited and can be flexibly selected based on needs.

[0257] In some embodiments, the positive electrode electrolyte particles comprise a sulfide electrolyte. In this case, the positive electrode electrolyte particles include a sulfide-based electrolyte.

[0258] By providing a sulfide electrolyte in the second coating sublayer of the positive electrode active coating particles, the positive electrode active particles can be endowed with high ion conductivity, which can greatly improve the interface ion conduction, thereby improving the electrochemical performance of the battery.

[0259] In a non-limiting manner, the electrolyte solid may include a sulfide-based electrolyte, in which case the second coating sublayer includes a sulfide-based electrolyte and the electrolyte solid contains the sulfide electrolyte. The weight percentage of the sulfide-based electrolyte in the second coating sublayer may be 0 wt % to 100 wt %. The weight percentage of the sulfide-based electrolyte in the second coating sublayer can be any of the following percentages or an interval consisting of any two of the following percentages: 0wt%, 1wt%, 2wt%, 4wt%, 5wt%, 6wt%, 8wt%, 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, 60wt%, 65wt%, 70wt%, 72wt%, 74wt%, 75wt%, 76wt%, 78wt%, 80wt%, 82wt%, 84wt%, 85wt%, 86wt%, 88wt%, 90wt%, 92wt%, 94wt%, 95wt%, 96wt%, 97wt%, 98wt%, 99wt%, 100wt%, etc. In some embodiments, the second coating sublayer includes a sulfide-based electrolyte, and the weight percentage of the sulfide-based electrolyte in the second coating sublayer may be 80 wt % to 100 wt %, optionally 90 wt % to 100 wt %.

[0260] Without limitation, the positive electrode electrolyte particles may include a sulfide-based electrolyte, and the weight percentage of the sulfide-based electrolyte in the positive electrode electrolyte particles may be 0 wt % to 100 wt %. The weight percentage of the sulfide-based electrolyte in the second coating sublayer can be any of the following percentages or an interval consisting of any two of the following percentages: 0wt%, 1wt%, 2wt%, 4wt%, 5wt%, 6wt%, 8wt%, 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, 60wt%, 65wt%, 70wt%, 72wt%, 74wt%, 75wt%, 76wt%, 78wt%, 80wt%, 82wt%, 84wt%, 85wt%, 86wt%, 88wt%, 90wt%, 92wt%, 94wt%, 95wt%, 96wt%, 97wt%, 98wt%, 99wt%, 100wt%, etc. In some embodiments, the positive electrode electrolyte particles include a sulfide-based electrolyte, and the weight percentage of the sulfide-based electrolyte in the positive electrode electrolyte particles may be 80 wt % to 100 wt %, and optionally 90 wt % to 100 wt %.

[0261] In some embodiments, the positive electrode active layer composition satisfies one or more of the following characteristics (any numerical parameter in the following characteristics can also be selected from any appropriate numerical value or range in the context):

[0262] The second coating sublayer includes a sulfide-based electrolyte, and the weight percentage of the sulfide-based electrolyte in the second coating sublayer is 80wt% to 100wt%, and optionally 90wt% to 100wt%;

[0263] The positive electrode electrolyte particles include a sulfide-based electrolyte, and the weight percentage of the sulfide-based electrolyte in the positive electrode electrolyte particles is 80 wt % to 100 wt %, and can be optionally 90 wt % to 100 wt %.

[0264] By controlling at least one of the weight percentage of the sulfide-based electrolyte in the second coating sublayer and the weight percentage of the sulfide-based electrolyte in the positive electrode electrolyte particles within the aforementioned range, it is beneficial to better improve the ion transport of the positive electrode active material layer and to reduce the interfacial impedance within the positive electrode active material layer.

[0265] In some embodiments, the mass ratio of the positive electrode electrolyte particles to the positive electrode active coating particles is 1% to 67%, optionally 1% to 45%, optionally 5% to 25%. Without limitation, the mass ratio of the positive electrode electrolyte particles to the positive electrode active coating particles can also be any of the following percentages or can be selected from an interval consisting of any two of the following percentages: 1%, 2%, 3%, 4%, 5%, 6%, 8%, 8.5%, 9%, 10%, 12%, 14%, 15%, 16%, 18%, 20%, 25%, 30%, 35%, 36%, 38%, 40%, 45%, etc.

[0266] The mass ratio of the positive electrode electrolyte particles to the positive electrode active coating particles can be controlled within the aforementioned range, which is beneficial for better providing overall electron and ion conductivity while taking into account high energy.

[0267] In some embodiments, the oxide positive electrode active material comprises a lithium transition metal oxide. In some embodiments, the oxide positive electrode active material may include, but is not limited to, a lithium transition metal oxide.

[0268] Without limitation, the weight percentage of the oxide positive electrode active material (such as lithium transition metal oxide) in the positive electrode active body can be greater than or equal to 50wt% (i.e., ≥50wt%), further can be greater than or equal to 60wt%, further can be greater than or equal to 80wt%, further can be greater than or equal to 90wt%, further can be greater than or equal to 95wt%, and further can be 100wt%. The weight percentage of the oxide positive electrode active material (such as lithium transition metal oxide) in the positive electrode active body can also be any of the following weight percentages or an interval consisting of any two of the following weight percentages: 50wt%, 55wt%, 60wt%, 65wt%, 70wt%, 72wt%, 74wt%, 75wt%, 76wt%, 78wt%, 80wt%, 82wt%, 84wt%, 85wt%, 86wt%, 88wt%, 90wt%, 92wt%, 94wt%, 95wt%, 96wt%, 97wt%, 98wt%, 99wt%, 100wt%, etc.

[0269] In some embodiments, the oxide positive electrode active material (such as lithium transition metal oxide) includes one or more of a lithium cobalt oxide-type positive electrode active material, a high nickel positive electrode active material, a lithium manganese-rich positive electrode active material, and a modified form of any of the foregoing positive electrode active materials; the modified form may include one or more of a doping modification and a coating modification.

[0270] It can be understood that the lithium cobalt oxide type positive electrode active material contains Li element, Co element and O element.

[0271] In some embodiments, the atomic molar ratio of the Co element to the O element is x2:2, and satisfies 0.9≤x2≤1. x2 can also be any of the following values ​​or a range consisting of any two of the following values: 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 1.00, etc.

[0272] In some embodiments, the atomic molar ratio of the Co element to the Li element is x2, and satisfies 0.9≤x2≤1. x2 can also be any of the following values ​​or a range consisting of any two of the following values: 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 1.00, etc.

[0273] Without limitation, the lithium cobalt oxide positive electrode active material may include Li, Co, and O in an atomic molar ratio of 1:x2:2, and satisfying 0.9≤x2≤1. x2 may also be any of the following values ​​or an interval consisting of any two of the following values: 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 1.00, etc.

[0274] In some embodiments, the lithium cobalt oxide positive electrode active material includes a chemical formula of LiCo x2 R 1-x2 In the lithium transition metal oxide of O2, R can be selected from one or more elements of Ni, Mg, Ti, Al, Cr, Fe, Nb and Ta.

[0275] Without limitation, the high nickel positive electrode active material may comprise Li, Ni, and O in an atomic molar ratio of 1:y2:2, and satisfying 0.6≤y2≤1. Without limitation, y2 may also be any of the following values ​​or an interval consisting of any two of the following values: 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.90, 0.95, 0.96, etc. Without limitation, y2 may also be selected from any of the following ranges: 0.8≤y2≤1, etc.

[0276] It can be understood that the high nickel positive electrode active material contains Li element, Ni element and O element.

[0277] In some embodiments, the atomic molar ratio of Ni to O is y2:2, and satisfies 0.6≤y2≤1. Without limitation, y2 can also be any of the following values, or a range consisting of any two of the following values: 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.90, 0.95, 0.96, etc. Without limitation, y2 can also be selected from any of the following ranges: 0.8≤y2≤1, etc.

[0278] In some embodiments, the atomic molar ratio of Ni to Li is y2, and satisfies 0.6≤y2≤1. Without limitation, y2 can also be any of the following values ​​or a range consisting of any two of the following values: 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.90, 0.95, 0.96, etc. Without limitation, y2 can also be selected from any of the following ranges: 0.8≤y2≤1, etc.

[0279] In some embodiments, the high-nickel positive electrode active material contains, in addition to nickel (Ni), cobalt (Co) and D, and the D element may be one or both of manganese (Mn) and aluminum (Al). In this case, the atomic number of nickel relative to lithium is y2. In some embodiments, y2 ≥ 0.6; further optionally, y2 ≥ 0.8; further optionally, y2 ≥ 0.9. y2 may also be any of the following values, or ≥ (greater than or equal to) any of the following values ​​and less than 1, or an interval selected from any two of the following values: 0.6, 0.7, 0.8, 0.9, 0.93, etc. y2 can also be selected from any of the following ranges: 0.6≤y2<1, 0.6≤y2≤1, 0.6≤y2≤0.95, 0.6≤y2≤0.94, 0.6≤y2≤0.93, 0.7≤y2<1, 0.7≤y2≤1, 0.7≤y2≤0.95, 0.7≤y2≤0.94, 0.7≤y2≤0.93, 0.8≤y2<1, 0.8≤y2≤1, 0.8≤y2≤0.95, 0.8≤y2≤0.94, 0.8≤y2≤0.93, 0.83≤y2<1, 0.83≤y2≤1, 0.83≤y2≤0.95, 0.83≤y2≤0.94, 0.83≤y2≤0.93, etc.

[0280] In some embodiments, the high nickel positive electrode active material comprises a chemical formula of LiNi y2 Co z2 D 1-y2-z2 Lithium transition metal oxide of O2, 0≤z2≤0.4, 0.6≤(y2+z2)≤1, D can be selected from one or more elements of Mn, Al, Zr, La, Ce, Ti, Mg, Nb, Ta, Mo and W. In some embodiments, D includes one or both of Mn element and Al element, and further, D can be selected from any one of Mn element and Al element. In some embodiments, D includes Mn element, and further, D can be selected from Mn element. Without limitation, z2 can also be any of the following values ​​or an interval consisting of any two of the following values: 0, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.36, 0.38, 0.39, 0.4, etc.

[0281] Non - restrictively, the lithium - rich manganese - based cathode active material contains Li element, Mn element and O element with an atomic molar ratio of (1 + p):(p + r(1 - p)):(2 + p), and 0 < p ≤ 1, 0 ≤ r ≤ 1. Non - restrictively, p can be any one of the following values, or selected from the intervals formed by any two of the following values, or greater than 0 and less than or equal to any one of the following values: 0.01, 0.02, 0.04, 0.05, 0.06, 0.08, 0.1, 0.12, 0.14, 0.15, 0.16, 0.18, 0.2, 0.22, 0.24, 0.25, 0.26, 0.28, 0.3, 0.32, 0.35, 0.36, 0.38, 0.4, 0.42, 0.44, 0.45, 0.46, 0.48, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.92, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, 1, etc. Non - restrictively, r can be any one of the following values or selected from the intervals formed by any two of the following values: 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, etc. p can also be selected from any one of the following ranges: 0.2 ≤ p ≤ 1.

[0282] In some embodiments, the lithium - rich manganese - based cathode active material includes a lithium transition metal oxide with the chemical formula pLi2MnO3·(1 - p)LiZO2, and Z can be selected from, but not limited to, one or more elements among nickel (Ni), cobalt (Co), manganese (Mn), chromium (Cr), iron (Fe), aluminum (Al), niobium (Nb), molybdenum (Mo) and ruthenium (Ru).

[0283] As a non - restrictive example of the oxide cathode active material, lithium transition metal oxides such as lithium cobalt oxide - type cathode active material, high - nickel cathode active material, lithium - rich manganese - based cathode active material, etc. are prone to release oxygen at high working voltages. When these lithium transition metal oxides are used as the cathode active material in the cathode active particles, by arranging the aforementioned cathode active layer composition in the cathode active material layer, it is beneficial to achieve both high energy density and long cycle performance of the sulfide solid - state battery under the possible oxygen release at the cathode.

[0284] When the cathode active material layer includes the aforementioned cathode active coated particles, further, it is also beneficial to inhibit the oxygen release of the cathode material, improve the crystal structure stability of the cathode active particles during battery cycling, inhibit the formation of the surface rock salt phase, and is beneficial to fully exert the cathode capacity and improve the long cycle performance of the battery.

[0285] In some embodiments, the oxide cathode active material includes one or more of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium-rich manganese cathode active material, and modified forms of any one of the foregoing lithium transition metal oxides; wherein, the chemical formula of the lithium-rich manganese cathode active material is pLi2MnO3·(1-p)LiZO2, Z can be selected from one or more elements including but not limited to Ni, Co, Mn, Cr, Fe, Al, Nb, Mo, and Ru, and 0 < p ≤ 1; the modified forms include one or more of doping modification and coating modification.

[0286] The structural design of introducing cathode active coating particles can be adopted in the cathode active particles containing the foregoing different types of oxide cathode active materials (such as lithium transition metal oxides), which can play the role of improving the discharge capacity, rate performance, and cycling performance of the solid-state battery as described above.

[0287] In some embodiments, the D v 50 or the particle size of the cathode electrolyte particles is 1 nm to 20 μm, and can be selected as 50 nm to 5 μm; wherein, D v 50 represents the particle size corresponding to when the cumulative volume distribution percentage of the multi-particle mixture reaches 50%, and the particle size refers to the maximum diameter among the diameters in each direction of the particles. The D v 50 or the particle size of the cathode electrolyte particles can also be any one of the following sizes or a range composed of any two of the following sizes: 1 nm, 5 nm, 10 nm, 20 nm, 50 mn, 60 nm, 80 nm, 100 nm (0.1 μm), 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.8 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, 5.5 μm, 6 μm, 6.5 μm, 7 μm, 7.5 μm, 8 μm, 8.5 μm, 9 μm, 9.5 μm, 10 μm, 10.5 μm, 11 μm, 11.5 μm, 12 μm, 12.5 μm, 13 μm, 13.5 μm, 14 μm, 14.5 μm, 15 μm, 15.5 μm, 16 μm, 16.5 μm, 17 μm, 17.5 μm, 18 μm, 18.5 μm, 19 μm, 19.5 μm, 20 μm, etc.

[0288] In the context of the present application, the volume cumulative distribution particle size D v N (where N represents any value selected from 0 to 100) can be used to characterize the particle size of the material, which refers to the particle size corresponding to when the cumulative volume distribution percentage of the material reaches N%, and the volume ratio of the particles with a particle size less than or equal to D v N is N%. Dv N can be obtained from the volume cumulative distribution curve of the material particle size. If there is no other explanation, the volume cumulative distribution curve starts from zero from the small particle size side. v 50 is used as an example. In this application, if there is no other description, D v 50 refers to the particle size corresponding to when the cumulative volume distribution percentage of the material reaches 50%. This parameter indicates that the particle size of 50% of the material volume is less than or equal to D v 50, and 50% of the volume of the material has a particle size larger than D v 50. Those skilled in the art will understand that v 50, and can be measured using instruments and methods known in the art. For example, it can be conveniently measured using a laser particle size analyzer, such as the Mastersizer 2000E laser particle size analyzer or the LS-909 laser particle size analyzer (Omega), manufactured by Malvern Instruments Ltd., UK, in accordance with GB / T 19077-2016 Particle Size Distribution by Laser Diffraction Method. Furthermore, for equipment such as the Malvern 2000 laser particle size analyzer, testing can be performed according to the standard procedure GB / T 19077-2016 / ISO 13320:2009.

[0289] In this application, unless otherwise specified, the "particle size" of a particle refers to the maximum diameter of the particle in each direction. Non-limiting examples of the particle involved in this application include positive electrode electrolyte particles, positive electrode active particles, positive electrode active coating particles, etc.

[0290] In this application, particle size analysis methods such as transmission electron microscopy (TEM) and laser particle size analyzer can be used to test and analyze the particle size of particles such as positive electrode electrolyte particles, positive electrode active particles, and positive electrode active coating particles. These test methods can also be used to test and analyze the particle size of other particulates involved in this application (such as the raw materials used to provide the particle body, etc.), such as parameters such as particle size and particle size distribution, and the average value of some size parameters.

[0291] By adjusting the D v 50 or particle size within the aforementioned range is beneficial to better improve the interface contact between the positive electrode layer and the battery layer while taking into account the overall ion conductivity of the positive electrode electrolyte particles, better improve the electrochemical performance of the battery, and take into account the manufacturing cost. The relatively small particle size of the positive electrode electrolyte particles is beneficial to improve the electrical contact between the positive electrode active materials in the positive electrode active particles, thereby promoting the capacity and rate performance of the solid-state battery. The relatively moderate D of the positive electrode electrolyte particles v 50 or more particle size is easier to manufacture.

[0292] In some embodiments, the D of the positive electrode active coating particles is v 50 or particle size is 0.1μm~20μm, optionally 1μm~10μm; wherein, D v 50 represents the particle size corresponding to the cumulative volume distribution percentage of the multi-particle mixture reaching 50%. v The particle size can also be any of the following sizes or an interval consisting of any two of the following sizes: 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.8 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, 5.5 μm, 6 μm, 6.5 μm, 7 μm, 7.5 μm, 8μm, 8.5μm, 9μm, 9.5μm, 10μm, 10.5μm, 11μm, 11.5μm, 12μm, 12.5μm, 13μm, 13.5μm, 14μm, 14.5μm, 15μm, 15.5μm, 16μm, 16.5μm, 17μm, 17.5μm, 18μm, 18.5μm, 19μm, 19.5μm, 20μm, etc.

[0293] By controlling the D v 50 or particle size within the above range is beneficial to improving the discharge capacity of the positive electrode active material and maintaining good contact between the positive electrode active material and the sulfide electrolyte in the composite positive electrode. Smaller-sized positive electrode active materials have shorter lithium ion transmission channels, which is beneficial to improving the discharge capacity of the positive electrode active material itself; larger-sized positive electrode active materials can be better wrapped by the sulfide electrolyte, and have better interfacial contact with the sulfide solid electrolyte, which is beneficial to the battery's cycling performance. Relatively moderate-sized positive electrode materials can enable solid-state batteries to have both high discharge capacity and excellent cycling performance.

[0294] In a second aspect of the present application, a positive electrode active coated particle is provided, which is the positive electrode active coated particle included in the positive electrode active layer composition described in the first aspect of the present application, and the second coating sublayer contains a sulfide electrolyte.

[0295] The positive electrode active coated particles can be applied to the positive electrode active material layer of a solid-state battery, so that the corresponding sulfide solid-state battery can have good discharge capacity, rate performance and cycle performance.

[0296] In a third aspect of the present application, a positive electrode film is provided.

[0297] In some embodiments, a positive electrode film is provided, which includes a positive electrode current collector and a positive electrode active material layer located on at least one side of the positive electrode current collector, wherein the positive electrode active material layer includes the positive electrode active layer composition described in the first aspect of the present application.

[0298] In some embodiments, a positive electrode film is provided, which includes a positive electrode current collector and a positive electrode active material layer located on at least one side of the positive electrode current collector, and the positive electrode active material layer includes the positive electrode active coating particles described in the second aspect of the present application.

[0299] Without limitation, the positive electrode film can be a standalone positive electrode film sheet or a positive electrode sheet, which can be used to assemble a solid-state battery. The positive electrode film can also be a positive electrode film layer present in a multi-layer composite structure. For example, the constituent materials of the positive electrode film layer can be pressed into a film on the surface of a solid electrolyte layer. As a non-limiting example, the positive electrode film can be a positive electrode layer or a portion of a positive electrode layer of a solid-state battery.

[0300] In yet another aspect of the present application, a positive electrode active material layer is provided, which is the positive electrode active material layer described in any embodiment of the present application.

[0301] As defined above, the positive electrode active material layer includes at least positive electrode active particles, which contain positive electrode active materials. It is understood that the positive electrode active particles include the positive electrode active coated particles mentioned above.

[0302] Without limitation, the weight percentage of the positive electrode active particles in the positive electrode active material layer may be 70 wt% to 99 wt%, and may be 80 wt% to 95 wt%. Without limitation, the weight percentage of the coated positive electrode active particles in the positive electrode active material layer may be 70 wt% to 99 wt%, and may be 80 wt% to 95 wt%. The weight percentage of the positive electrode active particles or the coated positive electrode active particles in the positive electrode active material layer may also be any of the following weight percentages or a range consisting of any two of the following weight percentages: 70 wt%, 72 wt%, 74 wt%, 75 wt%, 76 wt%, 78 wt%, 80 wt%, 82 wt%, 84 wt%, 85 wt%, 86 wt%, 88 wt%, 90 wt%, 92 wt%, 94 wt%, 95 wt%, 96 wt%, 97 wt%, 98 wt%, 99 wt%, etc.

[0303] In some embodiments, the positive electrode active material layer includes positive electrode electrolyte particles. Without limitation, the weight proportion of the positive electrode electrolyte particles in the positive electrode active material layer can be 0.1wt% to 30wt%, optionally 5wt% to 20wt%, and the weight proportion of the positive electrode electrolyte particles in the positive electrode active material layer can also be any of the following weight percentages or a range selected from any two of the following weight percentages: 0.1wt%, 0.2wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.8wt%, 1wt%, 1 .2wt%, 1.5wt%, 1.6wt%, 1.8wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 12wt%, 14wt%, 15wt%, 16wt%, 18wt%, 20wt%, 22wt%, 24wt%, 25wt%, 26wt%, 28wt%, 30wt%, etc.

[0304] In some embodiments, the positive electrode active material layer includes positive electrode active particles and positive electrode electrolyte particles, wherein the positive electrode active particles include positive electrode active coated particles.

[0305] In some embodiments, the positive electrode active material layer satisfies one or more of the following characteristics (any numerical parameter in the following characteristics can also be selected from any appropriate numerical value or range in the context):

[0306] The weight percentage of the positive electrode active coating particles in the positive electrode active material layer is 70wt% to 99wt%, and can be optionally 80wt% to 95wt%;

[0307] The weight percentage of the positive electrode electrolyte particles in the positive electrode active material layer is 0.1 wt% to 30 wt%, and can be optionally 5 wt% to 20 wt%.

[0308] By controlling the weight percentage of the positive electrode active coating particles in the positive electrode active material layer within the above range, it is advantageous to achieve both high energy density and cycle stability.

[0309] The weight percentage of the positive electrode electrolyte particles in the positive electrode active material layer can be controlled within the aforementioned range, which is beneficial for better providing overall ion conductivity.

[0310] In some embodiments, the positive electrode active material layer further includes one or more of a binder and a conductive agent.

[0311] In some embodiments, the cathode film satisfies one or more of the following characteristics (any numerical parameter in the following characteristics can also be selected from any appropriate value or range in the context):

[0312] The weight percentage of the binder in the positive electrode active material layer is 0.1wt% to 5wt%;

[0313] The weight percentage of the conductive agent in the positive electrode active material layer is 0.1 wt % to 5 wt %.

[0314] In some embodiments, the positive electrode active material layer includes a conductive agent (which may be referred to as a positive electrode conductive agent). As a non-limiting example, the positive electrode conductive agent may be a carbon conductive agent. Non-limitingly, the carbon conductive agent may include one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers. In some embodiments, the positive electrode conductive agent may include but is not limited to one or more of SP, KS-6, acetylene black, Ketjen black ECP with a branched structure, SFG-6, vapor-grown carbon fiber VGCF, carbon nanotubes (CNTs) and graphene. Non-limitingly, the weight percentage of the positive electrode conductive agent in the positive electrode active material layer may be 0 to 10 wt%, further 0 to 8 wt%, further 0 to 5 wt%, further 0.1 wt% to 3 wt%, based on the total weight of the positive electrode active material layer. The weight percentage of the positive electrode conductive agent in the positive electrode active material layer can also be 0.1wt% to 5wt%, 0.2wt% to 5wt%, 0.5wt% to 5wt%, 0.1wt% to 3wt%, etc. When the positive electrode material is prepared into the positive electrode active material layer by a dry method, the positive electrode conductive agent can be provided in the positive electrode material to improve the electron conductivity of the positive electrode active material layer.

[0315] In some embodiments, the positive electrode active material layer optionally includes a binder. As a non-limiting example, the binder may include one or more of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer and fluorine-containing acrylate resin. Typically, the weight percentage of the binder in the positive electrode active material layer may be 0 to 10 wt%, further 0 to 8 wt%, further 0.1 wt% to 5 wt%, further 1 wt% to 5 wt%, based on the total weight of the positive electrode active material layer. When the positive electrode material is formulated into a positive electrode slurry by a wet method and then prepared into a positive electrode active material layer, a binder may be provided in the positive electrode slurry to assist in film formation and to promote the formation of a good electrical contact network between the active particles of the positive electrode active material layer.

[0316] The following are some other descriptions about the positive electrode film.

[0317] In this application, unless otherwise specified, "positive electrode film" refers to a film that can be used as a positive electrode for a solid-state battery, including at least a positive electrode active material layer and usually also a positive electrode current collector. The positive electrode film includes the positive electrode active material layer described in the second aspect of this application.

[0318] In some embodiments, the positive electrode film includes a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector. The definition of the positive electrode active material layer can be found in the above text.

[0319] In some embodiments, referring to FIG. 8 , the positive electrode film 20 includes a positive electrode current collector 210 and a positive electrode active material layer 220 located on one side of the positive electrode current collector 210 .

[0320] In some embodiments, referring to FIG. 9 , the positive electrode film 20 includes a positive electrode current collector 210 and positive electrode active material layers 220 located on both sides of the positive electrode current collector 210 .

[0321] Without limitation, in the positive electrode film or positive electrode layer, the thickness of the positive electrode active material layer is 30μm to 400μm, optionally 60μm to 130μm, and can also be any of the following thicknesses or an interval consisting of any two of the following thicknesses: 30μm, 40μm, 50μm, 60μm, 80μm, 100μm, 120μm, 130μm, 140μm, 150μm, 160μm, 180μm, 200μm, etc. The thickness of the positive electrode active material layer may also be any of the following ranges: 40 μm to 400 μm, 40 μm to 300 μm, 40 μm to 200 μm, 40 μm to 150 μm, 40 μm to 130 μm, 40 μm to 120 μm, 50 μm to 400 μm, 50 μm to 300 μm, 50 μm to 200 μm, 50 μm to 150 μm, 50 μm to 130 μm, 50 μm to 120 μm, μm~120μm, 60μm~400μm, 60μm~300μm, 60μm~200μm, 60μm~150μm, 60μm~120μm, 80μm~400 μm, 80μm~300μm, 80μm~200μm, 80μm~150μm, 80μm~120μm, 100μm~200μm, 120μm~260μm, etc.

[0322] In this application, unless otherwise specified, the "thickness of the positive electrode active material layer" in the positive electrode film refers to the total thickness of the positive electrode film. When the positive electrode active material layer is provided on both sides of the positive electrode current collector, the thickness of the positive electrode active material layer refers to the sum of the thicknesses of both sides.

[0323] As a non-limiting example, the positive electrode current collector has two surfaces facing away from each other in its thickness direction, and the positive electrode active material layer is disposed on either or both of the two facing surfaces of the positive electrode current collector.

[0324] In some embodiments, the positive electrode active material in the positive electrode active particles includes an oxide positive electrode active material. Further, the positive electrode active material includes a lithium transition metal oxide.

[0325] Non-limitingly, the oxide positive electrode active material in the positive electrode active material (such as lithium transition metal oxide) may include lithium transition metal oxides that are well known in the art and can be used as positive electrode active materials in solid-state batteries, but are not limited thereto. Examples of lithium transition metal oxides may include, but are not limited to, one or more of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide and modified compounds thereof. Non-limiting examples of lithium cobalt oxide may include LiCoO2; non-limiting examples of lithium nickel oxide may include LiNiO2; non-limiting examples of lithium manganese oxide may include LiMnO2, LiMn2O4, etc.; non-limiting examples of lithium nickel cobalt manganese oxide may include LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also referred to as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2 (also referred to as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2 (also referred to as NCM 811 ) etc. Non-limiting examples of lithium nickel cobalt aluminum oxide may include LiNi 0.80 Co 0.15 Al 0.05 O2.

[0326] Taking a solid-state battery in which active ions include lithium ions as an example, it is understandable that the solid-state battery will be accompanied by the deintercalation and consumption of lithium (Li) during the charge and discharge process, and the content of Li in the positive electrode layer (including the positive electrode film in the context) is different when the battery is discharged to different states. In the exemplary description of the positive electrode active material in this application, unless otherwise specified, the content of Li can be the initial state of the material or the non-initial state after the charge and discharge cycle. The positive electrode active material is applied to the positive electrode layer in the solid-state battery system. After the charge and discharge cycle, the content of Li in the positive electrode active material contained in the positive electrode layer usually changes. Among them, the content of Li can be measured using atomic molar content, but is not limited to this. Regarding "the content of Li is the initial state of the material", the initial state of the material refers to the state before being placed in the positive electrode layer. It can be understood that new materials or new substances obtained by appropriate modification on the basis of the listed positive electrode active materials are also within the scope of positive electrode active materials. The aforementioned appropriate modification refers to an acceptable modification method for the positive electrode active material, and a non-limiting example is coating modification. In the exemplary descriptions of the positive electrode active material in this application, the oxygen (O) content is generally a theoretical value. Lattice oxygen release will cause the atomic molar content of oxygen to change, and the actual O content will fluctuate. The O content can be measured by atomic molar content, but is not limited to this.

[0327] In some embodiments, in addition to oxide positive electrode active materials (such as lithium transition metal oxides), the positive electrode active material may also include other positive electrode active materials that are well known in the art and can be used for solid-state batteries. As a non-limiting example, other positive electrode active materials that can be used for solid-state batteries may include one or more of the following materials: lithium-containing phosphates with an olivine structure and modified compounds thereof. However, the present application is not limited to these materials, and other existing materials that can be used as positive electrode active materials for solid-state batteries may also be used. These positive electrode active materials can be used alone or in combination of two or more. Non-limiting examples of lithium-containing phosphates with an olivine structure may include, but are not limited to, one or more of lithium iron phosphate, a composite material of lithium iron phosphate and carbon, lithium manganese phosphate, a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon. An example of lithium iron phosphate is LiFePO4 (also referred to as LFP). An example of lithium manganese phosphate is LiMnPO4.

[0328] In some embodiments, the lithium transition metal oxide includes lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium manganese-rich positive electrode active material (definition can be found below) and one or more modified forms of any of the foregoing positive electrode active materials; the modified form can include one or more of doping modification and coating modification.

[0329] Without limitation, the positive electrode active material layer may include positive electrode active particles, positive electrode electrolyte particles, a positive electrode conductive agent, and a binder. The type and content of each component can be found in the context of this application.

[0330] In this application, unless otherwise specified, a positive electrode active material layer sample can be obtained from a solid-state battery in the following manner: the battery can be disassembled to obtain an active material layer sample of the electrode plate, and the active material layer can be further analyzed by the following method: the nano-spatial dynamic resolution and layer-by-layer cutting technology of FIB-SEM are used to reconstruct the three-dimensional structure of the sample, and the distribution and proportion of each element are obtained by combining EDS element energy spectrum analysis, and finally the composition and thickness and other parameters of each structural layer of the active material layer are obtained through software quantitative analysis.

[0331] In this application, unless otherwise specified, the types and contents of components such as the positive electrode active particles (including positive electrode active coated particles) and positive electrode electrolyte particles in the positive electrode active material layer of the solid-state battery can be detected by the following method: the structure and composition analysis of the positive electrode active material layer can be tested and analyzed by focused electron beam (FIB) technology, scanning electron microscope (SEM) and elemental analysis technology, for example, it can be obtained by combining cryo-focused electron beam (FIB) continuous sectioning, cross-section SEM morphology observation, energy dispersive spectroscopy (EDS) element spectrum and three-dimensional reconstruction analysis software analysis. For example, a cryo-focused ion beam (FIB) is used to finely slice the sample layer by layer in the transverse direction at different thickness positions (the minimum scale can reach nanometer-level thin slices), and separate different layers of samples at different thickness positions. It can also be tested by scanning electron microscope (SEM), and the morphology, structure and element distribution of each layer of the cross section are analyzed under FIB continuous sectioning. The three-dimensional structure of the sample can be reconstructed in combination with three-dimensional structure reconstruction software, and the mass and / or volume of different areas of the sample to be tested can be estimated. As a non-limiting example, the above parameters may be tested and analyzed using a FEI Scios 2HiVac device.

[0332] In the present application, unless otherwise specified, the particle size and particle size distribution of each solid particle in the positive electrode active material layer sample of the solid-state battery can be analyzed in the following manner, which may include analyzing the particle size and particle size distribution of particle components such as positive electrode active particles and positive electrode electrolyte particles: In the present application, unless otherwise specified, FIB-SEM combined with EDS testing can be used to obtain a two-dimensional image with different color markings for different components, and particle components such as positive electrode active particles and positive electrode electrolyte particles can be distinguished according to the type of components. The particle size and particle size distribution of particle components such as positive electrode active particles and positive electrode electrolyte particles can be analyzed using the software provided by the EDS instrument.

[0333] In some embodiments, the positive electrode current collector may be a metal foil or a composite current collector. For example, aluminum foil may be used as the metal foil. In the positive electrode current collector, the composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer. In the positive electrode current collector, the composite current collector may be obtained by forming a metal material on a polymer material substrate. In the positive electrode current collector, non-limiting examples of the metal material may include at least one of aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy. In the positive electrode current collector, non-limiting examples of the polymer material substrate may include one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.

[0334] The positive electrode film can be prepared by a dry process or a wet process. For example, a dry process can be used to press the positive electrode film. Alternatively, a wet process can be used to apply the positive electrode film and then dry the positive electrode film.

[0335] In some embodiments, the positive electrode membrane (the positive electrode membrane can be used as the positive electrode sheet) can be prepared in the following manner: the components for preparing the positive electrode membrane, such as positive electrode active particles, positive electrode electrolyte particles, positive electrode conductive agent, binder and any other components are dry-mixed, and then the mixed material is heated and pressurized to form a mass material, which is hot rolled to form a self-supporting positive electrode sheet, and the self-supporting positive electrode sheet is hot-rolled with the positive electrode collector. The self-supporting positive electrode sheet can be compounded on at least one side (one side or two sides) of the positive electrode collector to obtain a positive electrode membrane. Without limitation, a double planetary mixer can be used for dry mixing. Without limitation, an internal mixer can be used for heating, pressurizing and kneading. Without limitation, the temperature for hot rolling can be 75°C to 85°C, and further such as 78°C, 80°C, 82°C, etc. The method of assembling solid-state batteries using positive electrode membranes can be suitable for industrial mass production.

[0336] In some embodiments, a positive electrode membrane can be prepared by dispersing the components used to prepare the positive electrode membrane, such as the positive electrode active particles, positive electrode electrolyte particles, positive electrode conductive agent, binder, and any other components, in an organic solvent to form a positive electrode slurry. Furthermore, the positive electrode slurry is coated on at least one surface of a positive electrode current collector. After drying and cold pressing, the positive electrode membrane can be obtained. The cold pressing can be performed using a cold rolling mill. The organic solvent in the positive electrode slurry can include one or more of p-xylene, trimethylbenzene, butyl butyrate, heptane, and can further be p-xylene. The surface of the positive electrode current collector coated with the positive electrode slurry can be a single surface of the positive electrode current collector or both surfaces of the positive electrode current collector. The solid content of the positive electrode slurry can be 40 wt% to 80 wt%. The viscosity of the positive electrode slurry at room temperature can be adjusted to 5000 mPa·s to 25000 mPa·s. When applying the positive electrode slurry, the coating unit area density based on dry weight (excluding solvent) can be 15 mg / cm 2 ~35mg / cm 2 The compaction density of the positive electrode membrane can be 3.0g / cm 3 ~3.6g / cm 3 , optional 3.3g / cm 3 ~3.5g / cm 3 .

[0337] The “compacted density” used in this application has a meaning well known in the art and is one of the reference indicators of material energy density. In this application, unless otherwise specified, the compacted density of an electrode layer refers to the ratio of the mass of the electrode active material layer to its volume. The compacted density of a positive electrode layer, a positive electrode sheet, a positive electrode film or a positive electrode membrane refers to the ratio of the mass of the positive electrode active material layer to its volume, and the compacted density of a negative electrode layer, a negative electrode sheet, a negative electrode film or a negative electrode membrane refers to the ratio of the mass of the negative electrode active material layer to its volume.

[0338] In another aspect of the present application, a positive electrode membrane is provided, which includes a positive electrode current collector and a positive electrode active material layer located on at least one side of the positive electrode current collector. The positive electrode active material layer is the positive electrode active material layer described in the second aspect of the present application.

[0339] The positive electrode film can be directly used as a positive electrode sheet to assemble a solid-state battery, but is not limited to this.

[0340] In a fourth aspect of the present application, there is provided a solid-state battery comprising a positive electrode layer, a solid electrolyte layer and a negative electrode layer;

[0341] The positive electrode layer includes at least one of the positive electrode active layer composition described in the first aspect of the present application, the positive electrode active coated particles described in the second aspect of the present application, and the positive electrode film described in the third aspect of the present application.

[0342] In a fifth aspect of the present application, an electrical device comprises at least one of the positive electrode film described in the third aspect of the present application and the solid-state battery described in the fourth aspect of the present application.

[0343] The use of the positive electrode active layer composition described in the first aspect of the present application, or the positive electrode active coated particles described in the second aspect of the present application, or the positive electrode film described in the third aspect of the present application in the preparation of solid-state batteries.

[0344] In any related embodiment of the aforementioned aspects, the solid-state battery may be a sulfide solid-state battery. The definition of sulfide solid-state battery can be found above.

[0345] In any related embodiment of the aforementioned aspects, the solid-state battery may be a sulfide all-solid-state battery. The definition of a sulfide all-solid-state battery can be found above.

[0346] In this application, the electrochemical performance of a battery, unless otherwise specified, generally includes comprehensive performance in terms of discharge capacity, rate capability and cycle performance.

[0347] A solid-state battery includes at least one solid-state battery cell. A solid-state battery may include one or more solid-state battery cells.

[0348] In this application, unless otherwise specified, a "solid-state battery cell" refers to a basic unit that can realize the mutual conversion of chemical energy and electrical energy, and its components are all solid. In some embodiments, the solid-state battery cell can be an all-solid-state battery cell.

[0349] Without limitation, a solid-state battery cell (which may be an all-solid-state battery cell) may include a positive electrode layer, a solid electrolyte layer, and a negative electrode layer, wherein the solid electrolyte layer is located between the positive electrode layer and the negative electrode layer. During the charge and discharge process of the battery, active ions are embedded and extracted back and forth between the positive electrode layer and the negative electrode layer. The solid electrolyte layer acts as an ion conductor between the positive electrode layer and the negative electrode layer, and can also isolate the positive electrode layer from the negative electrode layer to prevent short circuits between the positive and negative electrodes.

[0350] Unless otherwise specified, the positive electrode layer in the solid-state battery includes the positive electrode film described in the first aspect of the present application. It can be composed solely of the positive electrode film described in the first aspect of the present application, or it can be combined with other films suitable for the positive electrode to form a positive electrode layer.

[0351] The following is some description about the solid electrolyte layer.

[0352] The solid electrolyte layer plays the role of conducting ions between the positive electrode layer and the negative electrode layer, and can also isolate the positive electrode layer and the negative electrode layer to prevent the positive and negative electrodes from short-circuiting.

[0353] It is understood that the solid electrolyte layer includes a solid electrolyte. The solid electrolyte in the solid electrolyte layer can be a solid electrolyte known in the art that can be used in solid-state batteries.

[0354] The types of solid electrolytes present in different layers of a solid-state battery can be the same or different. For example, the solid electrolytes in the positive electrode electrolyte particles and the solid electrolyte layer can be the same or different.

[0355] As a non-limiting example, the positive electrode electrolyte particles and the solid electrolyte in the solid electrolyte layer can each independently include one or more of the following materials: one or more of a sulfide solid electrolyte, a halide solid electrolyte, an oxide solid electrolyte, a polymer solid electrolyte, etc. The type of sulfide solid electrolyte in the solid electrolyte layer can be the same as or different from the sulfide solid electrolyte in the positive electrode layer (such as the aforementioned positive electrode film). Taking a sulfide solid electrolyte as an example, a sulfide solid electrolyte refers to a solid electrolyte containing a sulfide electrolyte component, that is, a sulfide solid electrolyte is a sulfide-based electrolyte.

[0356] As another non-limiting example, the positive electrode electrolyte particles and the solid electrolyte in the solid electrolyte layer may each independently include but are not limited to one or more of an oxide solid electrolyte, a sulfide solid electrolyte and a halide solid electrolyte. In some of these embodiments, the positive electrode electrolyte particles and the solid electrolyte in the solid electrolyte layer may each independently include but are not limited to one or more of an Argyrodite-type sulfide electrolyte and a halide electrolyte. Among them, non-limiting examples of oxide solid electrolytes may include LISICON-type oxide electrolytes (such as γ-Li3PO4, etc.), NASICON-type oxide electrolytes (such as Li 1+x Al x Ge 2-x (PO4)3,Li 1+x Al x Ti 2-x (PO4)3, etc., 0≤x≤1), Garnet type (such as Li7La3Zr2O12, etc.), Perovskite type oxide electrolyte (such as Li 3x La 2 / 3-x TiO3, etc., 0≤x≤0.5) etc. Non-limiting examples of sulfide-based solid electrolytes may include Li 10 GeP2S 12 , Li2S-P2S5, Argyrodite type (such as Li6PS5Cl, Li 5.5 PS 5.5 Cl 1.5Non-limiting examples of the halide-based solid electrolyte may include one or more of Li3InCl6, Li3YCl6, Li3ScCl6, Li3ErCl6, Li2ZrCl6, etc.

[0357] In some embodiments, the solid electrolyte layer may be pressed from a solid electrolyte material into a solid electrolyte membrane.

[0358] In some embodiments, the thickness of the solid electrolyte layer may be 0.1 μm to 1000 μm, and may be optionally 10 μm to 100 μm, 100 μm to 800 μm, 500 μm to 800 μm, or the like.

[0359] The following is some description about the negative electrode layer.

[0360] The negative electrode layer can be provided by a negative electrode sheet or negative electrode membrane that can be used in solid-state batteries in the art. Alternatively, the negative electrode layer component materials can be directly pressed onto one surface of the solid electrolyte layer to form a negative electrode membrane layer. The negative electrode membrane can be combined with other films suitable for the negative electrode to form a negative electrode sheet or negative electrode layer.

[0361] The negative electrode layer can be prepared by a dry process or a wet process. For example, a dry process can be used to form a film by pressing. Another example is a wet process can be used to form a film by coating.

[0362] The negative electrode layer includes a negative electrode active material layer. The negative electrode active material layer includes negative electrode active particles. The negative electrode active particles contain a negative electrode active material.

[0363] Without limitation, the weight percentage of the negative electrode active particles or the negative electrode active material in the negative electrode active material layer may be ≥80 wt %, and further may be ≥90 wt %.

[0364] In some embodiments, the negative electrode active particles or the negative electrode active material are lithium-indium alloy (InLi alloy).

[0365] In some embodiments, the negative electrode layer is an InLi alloy film.

[0366] In some embodiments, the negative electrode active material may also adopt a negative electrode active material that is well known in the art and can be used for solid-state batteries. As a non-limiting example, the negative electrode active material may include one or more of the following materials: elemental silicon, elemental tin, silicon-carbon negative electrode (silicon-carbon composite material), silicon monoxide, graphite, and one or more of metallic lithium. However, the present application is not limited to these materials or substances, and other traditional materials that can be used as battery negative electrode active materials can also be used. These negative electrode active materials can be used alone or in combination of two or more.

[0367] In some embodiments, the negative electrode sheet or negative electrode film may include a negative electrode current collector and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector, the negative electrode active material layer including a negative electrode active material. As a non-limiting example, the negative electrode current collector has two surfaces that face away from each other in the thickness direction of the negative electrode current collector, and the negative electrode active material layer is disposed on either or both of the two facing surfaces of the negative electrode current collector. In some embodiments, the negative electrode current collector may be a metal foil or a composite current collector. For example, copper foil may be used as the metal foil. In the negative electrode current collector, the composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer. In the negative electrode current collector, the composite current collector may be formed by forming a metal material on a polymer material base layer. Non-limiting examples of the metal material in the negative electrode current collector may include one or more of copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. In the negative electrode current collector, non-limiting examples of the polymer material substrate may include one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), and the like.

[0368] In some embodiments, the negative electrode active material layer optionally includes a negative electrode conductive agent. Without limitation, the negative electrode conductive agent may include one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers. The weight percentage of the negative electrode conductive agent in the negative electrode active material layer may be 0 to 15 wt %, further preferably 0 to 10 wt %, and even more preferably 0 to 5 wt %.

[0369] In some embodiments, the negative electrode active material layer may optionally include a binder (referred to as a negative electrode binder). As non-limiting examples, the negative electrode binder may include one or more of styrene-butadiene rubber (SBR), polyacrylic acids (PAAs), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), and carboxymethyl chitosan (CMCS). Without limitation, the weight percentage of the negative electrode binder in the negative electrode active material layer may be 0-10 wt %, further 0-5 wt %, further 1 wt %-5 wt %, and further optionally 1 wt %-3 wt %.

[0370] In some embodiments, the negative electrode active material layer may optionally include other additives, such as a thickener (e.g., sodium carboxymethyl cellulose (CMC-Na)). The weight percentage of the other additives in the negative electrode active material layer may be 0-15 wt %, further preferably 0-10 wt %, further preferably 0-5 wt %, further preferably 0-3 wt %, and further preferably 0-2 wt %.

[0371] In some embodiments, the negative electrode sheet or negative electrode film can be prepared in the following manner: the components for preparing the negative electrode sheet or negative electrode film, such as negative electrode active particles, negative electrode conductive agent, binder (negative electrode binder) and any other components are dispersed in a solvent (a non-limiting example of the solvent is N-methylpyrrolidone (NMP)) to form a negative electrode slurry. Further, the negative electrode slurry is coated on at least one side of the negative electrode current collector, and after drying, cold pressing and other processes, the negative electrode sheet or negative electrode film can be obtained. The cold pressing can be performed using a cold rolling mill. The surface of the negative electrode current collector coated with the negative electrode slurry can be on a single surface of the negative electrode current collector or on both surfaces of the negative electrode current collector. The solid content of the negative electrode slurry can be 30wt% to 70wt%, and can optionally be 40wt% to 60wt%. The viscosity of the negative electrode slurry at room temperature can be adjusted to 2000mPa·s to 10000mPa·s, and can be optionally 3000mPa·s to 10000mPa·s. When applying the negative electrode slurry, the coating unit area density based on dry weight (excluding solvent) can be 75g / m 2 ~220g / m 2 The compaction density of the negative electrode sheet or negative electrode membrane can be 1.0g / cm 3 ~2.0g / cm 3 , optional 1.0g / cm 3 ~1.8g / cm 3 .

[0372] Without limitation, the positive electrode sheet, the solid electrolyte membrane and the negative electrode sheet may be stacked in sequence, the solid electrolyte membrane may be placed between the positive electrode sheet and the negative electrode sheet, and the solid-state battery cell may be prepared by hot rolling.

[0373] In a non-limiting manner, the positive electrode membrane, the solid electrolyte membrane and the negative electrode membrane may be stacked in sequence, the solid electrolyte membrane may be placed between the positive electrode membrane and the negative electrode membrane, and the solid-state battery cell may be prepared by hot rolling.

[0374] In some embodiments, the solid-state battery cell 5 includes a solid-state battery cell 52 .

[0375] In some embodiments, the solid-state battery cell is an all-solid-state battery cell.

[0376] In some embodiments, the solid-state battery cell 52 (which may be an all-solid-state battery cell) includes a positive electrode layer 200, a solid electrolyte layer 100, and a negative electrode layer 300 stacked in sequence, an example of which can be seen in Figure 10. Unless otherwise specified, the positive electrode layer 200 includes a positive electrode film 20.

[0377] In some embodiments, the solid-state battery cell 52 includes a positive electrode layer 200, a solid electrolyte layer 100, and a negative electrode layer 300 stacked in sequence. The positive electrode layer 200 includes a positive electrode film 20, which includes a positive electrode current collector 210 and positive electrode active material layers 220 located on both sides of the positive electrode current collector. The positive electrode active material layer 220 is disposed between the positive electrode current collector 210 and the solid electrolyte layer 100. An example of this is shown in FIG11 .

[0378] In some embodiments, the solid-state battery may include an outer packaging that can be used to encapsulate the solid-state battery cell.

[0379] In some embodiments, the outer packaging of the solid-state battery can be a hard shell, such as a hard plastic shell, an aluminum shell, a steel shell, etc. The outer packaging of the solid-state battery can also be a soft package, such as a bag-type soft package. The material of the soft package can be plastic. Further, non-limiting examples of plastic can include one or more of polypropylene, polybutylene terephthalate, and polybutylene succinate.

[0380] The present application has no particular limitation on the shape of the solid-state battery cell, which can be cylindrical, square, or any other shape. For example, FIG12 shows a solid-state battery cell 5 with a square structure as an example.

[0381] In some embodiments, referring to FIG13 , the outer packaging may include a shell 51 and a cover plate 53. Specifically, the shell 51 may include a bottom plate and side plates connected to the bottom plate, and the bottom plate and the side plates enclose a receiving cavity. The shell 51 has an opening connected to the receiving cavity, and the cover plate 53 can be covered on the opening to close the receiving cavity. The solid-state battery cell 52 is encapsulated in the receiving cavity. The number of solid-state battery cells 52 contained in the solid-state battery cell 5 can be one or more, and those skilled in the art can select according to actual needs.

[0382] The solid-state battery can be a battery module 4 or a battery pack 1 .

[0383] The battery module includes at least one solid-state battery cell. The number of solid-state battery cells contained in the battery module can be one or more, and those skilled in the art can select an appropriate number based on the application and capacity of the battery module.

[0384] Figure 14 shows an example battery module 4. Referring to Figure 14 , within the battery module 4, multiple solid-state battery cells 5 may be arranged sequentially along the length of the battery module 4. Of course, they may also be arranged in any other manner. Furthermore, the multiple solid-state battery cells 5 may be secured together using fasteners.

[0385] Optionally, the battery module 4 may further include a housing having a receiving space, and the plurality of solid-state battery cells 5 are received in the receiving space.

[0386] In some embodiments, the battery modules may be assembled into a battery pack. The battery pack may contain one or more battery modules. Those skilled in the art may select an appropriate number based on the application and capacity of the battery pack.

[0387] Figures 15 and 16 illustrate an example battery pack 1. Referring to Figures 15 and 16 , the battery pack 1 may include a battery box and multiple battery modules 4 disposed within the battery box. The battery box comprises an upper case 2 and a lower case 3. The upper case 2 can be positioned over the lower case 3 to form an enclosed space for accommodating the battery modules 4. The multiple battery modules 4 can be arranged in any manner within the battery box.

[0388] In some embodiments, the electrical device includes the solid-state battery of any embodiment provided herein.

[0389] Without limitation, solid-state batteries can be used as power sources for electrical devices or as energy storage units for electrical devices. Electrical devices may include, but are not limited to, mobile devices, electric vehicles, electric trains, ships and satellites, energy storage systems, and the like. Examples of mobile devices include, but are not limited to, mobile phones and laptops; examples of electric vehicles include, but are not limited to, pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, electric motorcycles, and electric tools. The electrical device may also be used in fields such as military equipment and aerospace, and in energy storage power systems such as hydropower, thermal power, wind power, and solar power stations.

[0390] As an electrical device, a solid-state battery can be selected according to its usage requirements.

[0391] Figure 17 shows an example of an electric device 6. This device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle. To meet the high power and high energy density requirements of the solid-state battery, a battery pack or battery module can be used.

[0392] Another example device may be a mobile phone, a tablet computer, a laptop computer, etc. Such a device is usually required to be lightweight and thin, and may use a solid-state battery as a power source.

[0393] Hereinafter, some embodiments of the present application will be described. The embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If the techniques or conditions are not specified in the embodiments, they shall be carried out in accordance with the description above, or in accordance with the techniques or conditions described in the literature in this field, or in accordance with the product instructions. The reagents or instruments used, for which the manufacturer is not specified, are conventional products that can be obtained commercially, or can be synthesized in a conventional manner from commercially available products. For example, the Se / Te complex involved is prepared by the following method: Se powder and Te powder are weighed in a stoichiometric ratio, vacuum-sealed in a quartz tube, and the vacuum degree is about 10 -5 Torr, and then heated at 900 ° C to obtain a uniformly mixed melt, and the melt was quenched in ice water to obtain a Se / Te complex (selenium tellurium alloy) with a specific atomic ratio.

[0394] Unless otherwise specified, in the following examples and comparative examples, raw materials with the same chemical formula are from the same synthesis batch or the same product number, or are prepared according to the same stoichiometric ratio and in accordance with the same method.

[0395] In the following examples, room temperature refers to 20°C to 30°C.

[0396] D v 50 tests:

[0397] In the following examples and comparative examples, the D of the positive electrode active material, the sulfide solid electrolyte and the non-carbon conductive material is v 50 The following method was used for testing and confirmation: Equipment model: Malvern 2000 (MasterSizer 2000) laser particle size analyzer, reference standard process: GB / T19077-2016 / ISO 13320:2009, test process: Take an appropriate amount of the sample to be tested (the sample concentration is guaranteed to be 8%-12% (w / v) shading), add 20mL of solvent (such as p-xylene or deionized water), and at the same time, ultraviolet light for 5 minutes (53KHz / 120W) to ensure that the sample is completely dispersed, and then measure the sample according to GB / T19077-2016 / ISO 13320:2009 standard.

[0398] The transmission electron microscope (TEM) is a FEI / Talos F200X instrument with a test accelerating voltage of 200 kV. This instrument integrates high-resolution scanning / transmission electron microscopy (STEM) and TEM imaging capabilities, along with energy-dispersive X-ray spectroscopy (EDS) signal detection and three-dimensional chemical characterization based on compositional mapping.

[0399] The NCM811 involved in the following examples is a high nickel lithium transition metal oxide, LiCoO2 is a lithium cobalt oxide lithium transition metal oxide, Li 1.2 Mn 0.48 Ni 0.16 Co 0.16 O2 is a lithium-rich manganese-based lithium transition metal oxide.

[0400] In the following examples and comparative examples, unless otherwise specified, steps involving sulfide-based electrolyte materials were performed in an argon atmosphere.

[0401] It should be noted that sulfide all-solid-state batteries are used as non-limiting examples of solid-state batteries in the following embodiments and examples.

[0402] Unless otherwise specified, the counting method for "approximate numbers" in micrometers (μm) or nanometers (nm) involved in the following examples is as follows: for values ​​accurate to one decimal place, the fluctuation range is within ±0.02; for values ​​accurate to the unit digit between 1 and 9, the fluctuation range is within ±0.2; for values ​​accurate to the unit digit between 10 and 99, the fluctuation range is within ±2.

[0403] Example 1. Positive electrode active coated particles (double-layer coated LiNi 0.8 Co 0.1 Mn 0.1 Preparation of O2 (NCM811) positive electrode active material

[0404] In this example, the positive electrode active body is NCM811, the first coating sublayer is a non-carbon conductive material with a weight percentage of 100wt%, the second coating sublayer is an electrolyte solid with a weight percentage of 100wt%, the non-carbon conductive material is Se element, and the electrolyte solid is a sulfide electrolyte Li 5.5 PS 4.5 Cl 1.5 (LPSCl).

[0405] LiNi is weighed according to the weight ratio 0.8 Co 0.1 Mn 0.1 O2 positive electrode (D v 50 is about 4μm) and single substance Se powder (D v 50 is about 30 μm), and a dry coating device is used for uniform mixing, and the coating amount is 1 wt%. The obtained mixed material is heat-treated at 300 ° C in an argon atmosphere for 1 h to obtain a 1 wt% Se-coated NCM811 positive electrode material (denoted as NCM811@Se).

[0406] Weigh the amount of Li according to the coating amount 5.5 PS 4.5 Cl1.5 (LPSCl) sulfide electrolyte (D v 50 (1 μm) was added to anhydrous acetonitrile solution and stirred evenly, and then NCM811@Se positive electrode material and LPSCl electrolyte coating amount were added. Stirring was continued for 3 h, and the resulting solution was vacuum dried at 150 ° C for 5 h to obtain a double-layer coated NCM811@Se@LPSCl positive electrode material.

[0407] According to the results of transmission electron microscopy observation, see Figure 18, a double-layer coating structure of positive electrode active coated particles was prepared, wherein the thickness of the Se coating layer (first coating sublayer) was about 2nm, the thickness of the LPSCl electrolyte coating layer (second coating sublayer) was about 4nm, and the total coating thickness was about 6nm. Further, the elemental composition of each coating layer was confirmed by EDS energy spectrum scanning results, and the results can be seen in Figure 19. According to the EDS analysis results, the prepared positive electrode active particles have a double layer of coating material (i.e., positive electrode active coated particles), the inner layer (first coating sublayer) is Se, and the outer layer (second coating sublayer) is LPSCl electrolyte, which is consistent with the design.

[0408] (2) Preparation of solid-state battery positive electrode membrane (all-solid-state battery positive electrode sheet)

[0409] The double-layer coated NCM811 cathode material and LPSCl sulfide electrolyte (D v 50 is 1 μm), VGCF and binder polytetrafluoroethylene (PTFE) are weighed in a weight ratio of 85:13:1:1, and mixed evenly in a double planetary mixer. The mixed powder is then heated and pressurized in an internal mixer to form a mass material, which is then hot-rolled at 80°C to form a self-supporting positive electrode sheet, and finally hot-rolled with a current collector Al foil to obtain a positive electrode membrane.

[0410] (3) Assembly of solid-state batteries (sulfide all-solid-state batteries)

[0411] 100mg of the sulfide electrolyte LPSCl was weighed and added to a battery mold. Pressurization was then performed to form a solid electrolyte membrane. The positive electrode membrane was then placed on one side of the solid electrolyte membrane, and an InLi alloy negative electrode layer was placed on the other side to assemble the all-solid-state battery. The battery's test window was 2.8-4.3V vs. Li.

[0412] Examples 2 to 6: Changing the composition of the non-carbon conductive material in the first coating sublayer.

[0413] A solid-state battery was prepared using a method substantially the same as that in Example 1, with the difference being that the composition of the first conductive material in the first coating sublayer was different.

[0414] In Example 2, Te is used to replace Se in Example 1.

[0415] Example 3: Se 0.4 Te 0.6 The composite replaces the Se element in Example 1.

[0416] Example 4 uses Se 0.6 Te 0.4 The composite replaces the Se element in Example 1.

[0417] In Example 5, a mixture of Se and Te in a weight ratio of 1:1 is used to replace the Se in Example 1.

[0418] In Example 6, a mixture of Se and Te in a weight ratio of 3:7 is used to replace the Se in Example 1.

[0419] Examples 7 to 10: Solid-state batteries are prepared using a method basically the same as that of Example 1, with the difference being that the amount of non-carbon conductive material coated in the first coating sublayer is changed, and at least one parameter of the weight proportion of the first coating sublayer in the positive electrode active coating particles and the thickness of the first coating sublayer is changed.

[0420] Examples 11 to 16: Solid-state batteries were prepared using a method substantially the same as that of Example 1, except that the composition of the second coating sublayer was changed, wherein the chemical composition of the electrolyte solid material included in the second coating sublayer and the raw material D v 50. At least one parameter of the weight ratio of the second coating sublayer in the positive electrode active coating particles and the thickness of the second coating sublayer is different.

[0421] Among them, the electrolyte solid material used in Example 11 is LGPS sulfide electrolyte Li 10 GeP2S 12 The solid electrolyte used in Example 12 is 75Li2S-25P2S5, which is a lithium sulfide pentasulfide diphosphorus complex sulfide electrolyte (75Li2S)·(25P2S5), which can be seen in Table 2. Examples 17 to 21: Solid-state batteries are prepared using a method substantially the same as that of Example 1, except that the positive electrode active body is different, wherein the chemical composition of the positive electrode active material contained in the positive electrode active body and the raw material D v At least one parameter in 50 is different.

[0422] Examples 22 to 26: Solid-state batteries were prepared using a method substantially the same as that of Example 1, except that the composition of the positive electrode active material layer was different, wherein the chemical composition of the electrolyte solid material included in the positive electrode electrolyte particles and the raw material D v50. At least one of the following parameters is different: the weight percentage of the positive electrode electrolyte particles in the positive electrode active material layer, the weight proportion of the positive electrode active coating particles in the positive electrode active material layer, and the mass ratio of the positive electrode electrolyte particles to the positive electrode active coating particles.

[0423] Example 27: A solid-state battery is prepared using a method substantially the same as that of Example 1, except that no sulfide electrolyte is provided in the second coating sublayer.

[0424] Example 28: A solid-state battery is prepared using a method substantially the same as that of Example 1, except that no sulfide electrolyte is provided in the positive electrode electrolyte layer.

[0425] Comparative Example 1: The positive electrode active particles have no coating layer, including no oxygen storage layer.

[0426] A solid-state battery was prepared by a method substantially the same as that in Example 1, except that the positive electrode active particles were different, and NCM811 without any surface coating was used instead of the double-layer coated NCM811@Se@LPSCl positive electrode material in Example 1.

[0427] Comparative Example 2: Only the first cladding sublayer (Se layer) was provided.

[0428] A solid-state battery was prepared using a method substantially the same as that in Example 1, except that the second coating sublayer was omitted.

[0429] Comparative Example 3: Only the second cladding sublayer (LPSC1 layer) is provided.

[0430] A solid-state battery was prepared using a method substantially the same as that in Example 1, except that the first coating sublayer was omitted.

[0431] Comparative Example 4: A solid-state battery was prepared using a method substantially the same as that of Example 1, except that the non-carbon conductive material was replaced with a carbon conductive material.

[0432] The relevant parameters of Examples 1 to 28 and Comparative Examples 1 to 4 can also be found in Tables 1-4.

[0433] Table 1. Related parameters of the first coating sublayer of the positive electrode active coating particles

[0434] Table 2. Related parameters of the second coating sublayer of the positive electrode active coating particles

[0435] Table 3. Related parameters of cathode electrolyte particles

[0436] Table 4. Some parameters of the positive electrode active body and positive electrode active material layer

[0437] Performance testing and analysis:

[0438] The electrochemical performance of the positive electrode and the corresponding all-solid-state battery was tested using a solid-state mold battery, and the battery test window was 2.8V to 4.3V (relative to lithium potential).

[0439] 1. First discharge capacity

[0440] The test process is as follows: the assembled all-solid-state battery is charged to 3.68V (4.3V vs. lithium) at a current density of 0.1C, allowed to rest for 10 minutes, and then discharged to 2.18V (2.8V vs. lithium) at a current density of 0.1C to obtain the battery's initial discharge capacity. The battery is tested at 25±3°C, where 1C = 200mA / g.

[0441] 2. First Coulombic efficiency

[0442] The first coulombic efficiency of the battery can be obtained by dividing the first discharge capacity obtained by the first charge capacity tested at 0.1C.

[0443] 3. Rate performance

[0444] The test process is as follows: the charge rate of the all-solid-state battery is fixed at 0.1C, and then discharged at the rates of 0.1C, 0.33C, 1C, 2C, and 3C, respectively. Each rate is cycled 3 times. The battery voltage test window is 2.8~4.3V vs.Li + / Li, the battery was tested at 25±3°C, where 1C=200mA / g.

[0445] 4. Cycle performance:

[0446] The test process is as follows: the assembled all-solid-state battery is first activated by charging and discharging at 0.1C for 3 cycles, and then the battery is charged and discharged for a long cycle test at 0.33C for 200 cycles, and the battery's cycle capacity retention rate is calculated. The battery's voltage test window is 2.8~4.3Vvs.Li + / Li (for lithium potential, active ions are Li + ), the battery was tested at 25±3°C, where 1C = 200 mA / g. The test results can be found in Table 4, "200-cycle capacity retention, 0.33C".

[0447] Test analysis results:

[0448] The test results can be found in Table 5.

[0449] The sulfide solid-state batteries prepared in Examples 1 to 28 all used the positive electrode active layer composition provided in this application, comprising positive electrode active coating particles and positive electrode electrolyte particles. The positive electrode active coating particles comprised a first coating sublayer comprising a non-carbon conductive material and a second coating sublayer comprising an electrolyte solid material, and at least one of the first coating sublayer and the positive electrode electrolyte particles comprised a sulfide solid electrolyte. The sulfide solid-state batteries prepared in Examples 1 to 28 all exhibited good discharge capacity, rate capability, and cycling performance, as well as good first coulombic efficiency.

[0450] In Example 3-6, the first coating sublayer includes both Se and Te elements. Due to the synergistic effect between Se and Te, Se elements are more likely to combine with peroxide ions to form SeO3 2- , which is more conducive to inhibiting the decomposition of sulfide electrolytes; Te elements can give non-carbon conductive materials higher electronic conductivity and provide more sufficient electronic conduction channels. At this time, the non-carbon conductive material is Se x Te 1-x When Se and Te are mixed and added, solid-state batteries have very good electrochemical performance. x Te 1-x Se and Te in the complex are combined at the atomic scale, and the combined effect of the two elements is very excellent.

[0451] The positive electrode active particles in Comparative Example 1 use positive electrode active materials without any coating layer to replace the positive electrode active coated particles with double coating layers in Examples 1-16. The discharge capacity, rate performance and cycle performance of Comparative Example 1 are significantly deteriorated. In addition, the first coulomb efficiency is also significantly reduced. It can be seen that after the first coating sublayer and the second coating sublayer are introduced at the same time, not only the interface side reactions between the positive electrode active material and the positive electrode electrolyte particles are suppressed, but also the interface electronic and ionic conductivity are improved at the same time. Therefore, the discharge capacity, first coulomb efficiency, rate performance and cycle performance of Examples 1-16 are significantly improved relative to those of Comparative Example 1.

[0452] The positive active particles in Comparative Example 2 were only provided with the first coating sublayer. Compared with Examples 1-6 and 11-16, the discharge capacity, rate performance and cycle performance of Comparative Example 2 deteriorated to varying degrees. In addition, the first coulombic efficiency also decreased.

[0453] In addition, a comparison between Comparative Example 1 and Comparative Example 2 also demonstrates that the introduction of the first coating sublayer can inhibit interfacial side reactions, thereby improving the structural stability of the positive electrode material and further improving the electrochemical performance of the battery.

[0454] The positive active particles in Comparative Example 3 were only provided with a second coating sublayer. Compared with Examples 1-10, the discharge capacity, rate capability, and cycle performance of Comparative Example 3 deteriorated significantly. In addition, the first coulombic efficiency also decreased significantly. Comparative Example 3 omitted the first coating sublayer and directly coated the sulfide electrolyte (LPSCl) on the surface of the positive active material (NCM811). During the heat treatment process, the positive active material directly reacted with the sulfide electrolyte, resulting in structural destruction of the positive active material and the formation of a high interfacial resistance impedance layer, resulting in poor discharge capacity and cycle performance of the battery.

[0455] The positive electrode active particles in Comparative Example 4 use carbon conductive materials instead of the non-carbon conductive materials in the first coating sublayer of Examples 1-6. The discharge capacity, rate performance and cycle performance of Comparative Example 3 deteriorate to varying degrees. In addition, the first coulombic efficiency also decreases significantly.

[0456] Table 5. Electrochemical performance test results

[0457] The description of each embodiment above tends to emphasize the differences between the embodiments, and the same or similar aspects can be referenced to each other. For the sake of brevity, this article will not go into details. The technical features of the embodiments described above can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples. Within the scope of the technical solution of this application, embodiments with essentially the same composition as the technical idea and the same effect are included in the technical scope of this application. The embodiments described above only express several embodiments of the present application, and the description is relatively detailed, but it cannot be understood as a limitation on the scope of the patent. In addition, without departing from the scope of the main purpose of this application, other methods of applying various modifications that can be thought of by those skilled in the art to the embodiments and combining some of the constituent elements in the embodiments are also included in the scope of this application.

Claims

1. A positive electrode active layer composition comprising positive electrode active coating particles and positive electrode electrolyte particles; The positive electrode active coated particles include a positive electrode active body and a coating layer coated on at least a portion of the surface of the positive electrode active body, the coating layer includes a first coating sublayer and a second coating sublayer, and the second coating sublayer is located on a side of the first coating sublayer away from the positive electrode active body; The positive electrode active body includes a positive electrode active material, and the positive electrode active material includes an oxide positive electrode active material; The first coating sublayer includes a non-carbon conductive material, and the non-carbon conductive material includes at least one of a Se element, a Te element, and a Se / Te complex, wherein the chemical formula of the Se / Te complex is Se x Te 1-x , 0 <x<1; The second coating sublayer includes an electrolyte solid; At least one of the positive electrode electrolyte particles and the second coating sublayer includes a sulfide electrolyte.

2. The positive electrode active layer composition according to claim 1, wherein The electronic conductivity of the non-carbon conductive material at at least one temperature between 20° C. and 100° C. or at least a portion of the temperature range is greater than or equal to that of Se elemental substance.

3. The positive electrode active layer composition according to claim 1 or 2, wherein The weight percentage of Te element in the non-carbon conductive material is 50 wt % to 100 wt %.

4. The positive electrode active layer composition according to claim 1 or 2, wherein The weight percentage of Te element in the non-carbon conductive material is 60 wt % to 100 wt %.

5. The positive electrode active layer composition according to any one of claims 1 to 3, wherein At least one of the Se element, Te element and Se / Te complex is recorded as a first conductive material, and the weight percentage of the first conductive material in the non-carbon conductive material is 80wt% to 100wt%, and can be optionally 90wt% to 100wt%.

6. The positive electrode active layer composition according to any one of claims 1 to 5, wherein The positive electrode active coated particles meet one or more of the following characteristics: The weight percentage of the first coating sublayer in the positive electrode active coating particles is 0.1wt% to 10wt%; The weight percentage of the non-carbon conductive material in the first coating sublayer is 80wt% to 100wt%; The thickness of the first cladding sublayer is 0.1 nm to 50 nm.

7. The positive electrode active layer composition according to claim 6, wherein The positive electrode active coated particles meet one or more of the following characteristics: The weight percentage of the first coating sublayer in the positive electrode active coating particles is 0.5wt% to 5wt%; The weight percentage of the non-carbon conductive material in the first coating sublayer is 90wt% to 100wt%; The thickness of the first cladding sublayer is 0.5 nm to 10 nm.

8. The positive electrode active layer composition according to any one of claims 1 to 7, wherein The sulfide electrolyte includes one or more of an argyrodite-type sulfide electrolyte, an LGPS-type sulfide electrolyte, and a lithium sulfide pentasulfide diphosphorus complex-type sulfide electrolyte.

9. The positive electrode active layer composition according to claim 8, wherein The sulfide electrolyte satisfies one or more of the following characteristics: The argyrodite-type sulfide electrolyte includes a chemical formula of Li 6±s P 1-j A j S 5±s-t B t X 1±s A sulfide electrolyte, wherein 0≤j<1, 0≤t<1, 0≤s<1, A is selected from one or more elements of Ge, Si, Sn and Sb, B is selected from one or more elements of O, Se and Te, and X is selected from one or more elements of Cl, Br, I and F; The LGPS sulfide electrolyte includes a chemical formula of Li 10±δ5 Ge 1-g G g P 2-q Q q S 12-w W w A sulfide electrolyte, wherein 0≤δ5<1, 0≤g≤1, 0≤q≤2, 0≤w<1, G is one or two elements of Si and Sn, Q is Sb, and W is one or more elements selected from O, Se, Te, Cl, Br, I and F; The lithium sulfide - phosphorus pentasulfide composite sulfide electrolyte includes a sulfide electrolyte with the chemical formula (100 - u - v)Li2S·uP2S5·vM m N n , where 0 < u < 100, 0 ≤ v < 100, 0 ≤ u + v < 100, 0 ≤ m < 4, 0 ≤ n < 6, M is selected from one or more elements of Li, B, Ge, Si, Sn, and Sb, and N is selected from one or more elements of S, Se, Te, O, Cl, Br, I, and F.

10. The positive electrode active layer composition according to any one of claims 1 to 9, wherein The positive electrode active coated particles meet one or more of the following characteristics: The weight percentage of the second coating sublayer in the positive electrode active coating particles is 0.1wt% to 10wt%; The weight percentage of the electrolyte solid in the second coating sublayer is 50wt% to 100wt%; The electrolyte solid material includes a sulfide-based electrolyte, and the weight percentage of the sulfide-based electrolyte in the electrolyte solid material is 50wt% to 100wt%; The thickness of the second cladding sublayer is 0.1 nm to 50 nm.

11. The positive electrode active layer composition according to claim 10, wherein The positive electrode active coated particles meet one or more of the following characteristics: The weight percentage of the second coating sublayer in the positive electrode active coating particles is 0.5wt% to 5wt%; The weight percentage of the electrolyte solid in the second coating sublayer is 80wt% to 100wt%, and can be optionally 90wt% to 100wt%; The electrolyte solid material includes a sulfide-based electrolyte, and the weight percentage of the sulfide-based electrolyte in the electrolyte solid material is 80wt% to 100wt%, and can further be 90wt% to 100wt%; The thickness of the second cladding sublayer is 0.5 nm to 10 nm.

12. The positive electrode active layer composition according to any one of claims 1 to 11, wherein The positive electrode active layer composition satisfies any of the following conditions: The positive electrode electrolyte particles and the second coating sublayer both contain a sulfide electrolyte; One of the positive electrode electrolyte particles and the second coating sublayer comprises a sulfide electrolyte, and the other is an optional solid electrolyte.

13. The positive electrode active layer composition according to claim 12, wherein One of the positive electrode electrolyte particle and the second coating sublayer comprises a sulfide electrolyte, and the other comprises one or more of a sulfide electrolyte, a halide electrolyte, an oxide electrolyte, and a polymer electrolyte.

14. The positive electrode active layer composition according to any one of claims 13, wherein The second coating sublayer comprises a sulfide electrolyte.

15. The positive electrode active layer composition according to any one of claims 12, wherein The positive electrode active layer composition satisfies one or more of the following characteristics: The second coating sublayer includes a sulfide-based electrolyte, and the weight percentage of the sulfide-based electrolyte in the second coating sublayer is 80wt% to 100wt%, and optionally 90wt% to 100wt%; The positive electrode electrolyte particles include a sulfide-based electrolyte, and the weight percentage of the sulfide-based electrolyte in the positive electrode electrolyte particles is 80 wt % to 100 wt %, and can be optionally 90 wt % to 100 wt %.

16. The positive electrode active layer composition according to any one of claims 1 to 15, wherein The mass ratio of the positive electrode electrolyte particles to the positive electrode active coating particles is 1% to 67%, optionally 1% to 45%, and further optionally 5% to 25%.

17. The positive electrode active layer composition according to any one of claims 1 to 16, wherein The oxide positive electrode active material includes lithium transition metal oxide; Optionally, the lithium transition metal oxide includes one or more of a lithium cobalt oxide-type positive electrode active material, a high nickel positive electrode active material, a lithium-rich manganese-based positive electrode active material, and a modified form of any of the foregoing positive electrode active materials; the modified form includes one or more of doping modification and coating modification; Optionally, The lithium cobalt oxide type positive electrode active material comprises Li, Co and O, wherein the atomic molar ratio of Co to O is x2:2, and satisfies 0.9≤x2≤1; alternatively, the lithium cobalt oxide type positive electrode active material comprises Li, Co and O in an atomic molar ratio of 1:x2:2, and satisfies 0.9≤x2≤1; The high-nickel positive electrode active material comprises Li, Ni and O, wherein the atomic molar ratio of Ni to O is y2:2, and satisfies 0.6≤y2≤1; alternatively, the high-nickel positive electrode active material comprises Li, Ni and O in an atomic molar ratio of 1:y2:2, and satisfies 0.6≤y2≤1, alternatively, 0.8≤y2≤1; The lithium-rich manganese-based cathode active material contains Li element, Mn element and O element with an atomic molar ratio of (1 + p):(p + r(1 - p)):(2 + p), and satisfies 0 < p ≤ 1, 0 ≤ r ≤ 1; optionally, 0.2 ≤ p ≤ 1.

18. The positive electrode active layer composition according to claim 17, wherein The lithium transition metal oxide satisfies one or more of the following characteristics: The lithium cobalt oxide positive electrode active material includes a chemical formula of LiCo x2 R 1-x2 O2 lithium transition metal oxide, R is selected from one or more elements of Ni, Mg, Ti, Al, Cr, Fe, Nb and Ta; The high nickel positive electrode active material includes a chemical formula of LiNi y2 Co z2 D 1-y2-z2 A lithium transition metal oxide of O2, 0≤z2≤0.4, 0.6≤(y2+z2)≤1, D is selected from one or more elements of Mn, Al, Zr, La, Ce, Ti, Mg, Nb, Ta, Mo and W; optionally, D includes Mn; The lithium-rich manganese-based cathode active material includes a lithium transition metal oxide with the chemical formula pLi2MnO3·(1 - p)LiZO2, where Z is selected from one or more elements of Ni, Co, Mn, Cr, Fe, Al, Nb, Mo and Ru.

19. The positive electrode active layer composition according to any one of claims 1 to 16, wherein The oxide cathode active material includes one or more of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium-rich manganese cathode active material and a modified form of any of the foregoing lithium transition metal oxides; wherein, the chemical formula of the lithium-rich manganese cathode active material is pLi2MnO3·(1 - p)LiZO2, Z is selected from one or more elements of Ni, Co, Mn, Cr, Fe, Al, Nb, Mo and Ru, 0 < p ≤ 1; the modified form includes one or more of doping modification and coating modification.

20. The positive electrode active layer composition according to any one of claims 1 to 19, wherein The D of the positive electrode electrolyte particles v 50 or particle size is 1nm~20μm; among them, D v 50 represents the particle size corresponding to when the cumulative volume distribution percentage of the multi-particle mixture reaches 50%, and the particle size refers to the maximum diameter of the particle in all directions.

21. The positive electrode active layer composition according to any one of claims 20, wherein The D of the positive electrode electrolyte particles v 50 is 50nm~5μm.

22. The positive electrode active layer composition according to any one of claims 1 to 21, wherein The D of the positive electrode active coating particles v 50 or particle size is 0.1μm~20μm; among them, D v 50 represents the particle size corresponding to when the cumulative volume distribution percentage of the multi-particle mixture reaches 50%.

23. The positive electrode active layer composition according to claim 22, wherein The D of the positive electrode active coating particles v 50 is 1μm~10μm.

24. A positive electrode active coating particle, which is the positive electrode active coating particle included in the positive electrode active layer composition according to any one of claims 1 to 23, and the second coating sublayer contains a sulfide electrolyte.

25. A positive electrode film, which includes a positive electrode current collector and a positive electrode active material layer located on at least one side of the positive electrode current collector, and the positive electrode active material layer includes the positive electrode active layer composition according to any one of claims 1 to 23.

26. A positive electrode film, which includes a positive electrode current collector and a positive electrode active material layer located on at least one side of the positive electrode current collector, and the positive electrode active material layer includes the positive electrode active coating particle according to claim 24.

27. The positive electrode film according to claim 25 or 26, wherein The positive electrode active material layer satisfies one or more of the following characteristics: The weight percentage of the positive electrode active coating particle in the positive electrode active material layer is 70wt% - 99wt%, optionally 80wt% - 95wt%; The weight percentage of the positive electrode electrolyte particle in the positive electrode active material layer is 0.1wt% - 30wt%, optionally 5wt% - 20wt%.

28. The positive electrode film according to any one of claims 25 to 27, wherein The positive electrode active material layer further includes one or more of a binder and a conductive agent; Optionally, the positive electrode film satisfies one or more of the following characteristics: The weight percentage of the binder in the positive electrode active material layer is 0.1wt% - 5wt%; The weight percentage of the conductive agent in the positive electrode active material layer is 0.1wt% - 5wt%.

29. A solid-state battery, which includes a positive electrode layer, a solid electrolyte layer and a negative electrode layer; The positive electrode layer includes at least one of the positive electrode active layer composition according to any one of claims 1 to 23, the positive electrode active coating particle according to claim 24, and the positive electrode film according to any one of claims 25 to 28.

30. The solid-state battery according to claim 29, wherein The solid-state battery is a sulfide solid-state battery.

31. The solid-state battery according to claim 29 or 30, wherein: The solid-state battery is a sulfide all-solid-state battery.

32. An electrical device comprising at least one of the cathode film according to any one of claims 25 to 28 and the solid-state battery according to any one of claims 29 to 31.

33. Use of the positive electrode active layer composition according to any one of claims 1 to 23, or the positive electrode active coated particles according to claim 24, or the positive electrode film according to any one of claims 25 to 28 in the preparation of a solid-state battery; Optionally, the solid-state battery is a sulfide solid-state battery; Further optionally, the solid-state battery is a sulfide all-solid-state battery.

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