Battery cell, battery device , and electric device

Abstract

Provided in the present application are a battery cell, a battery device, and an electric device. The battery cell comprises a housing and an electrode assembly. The electrode assembly is accommodated in the housing, and comprises a first electrode sheet, a solid electrolyte layer, and a second electrode sheet that are sequentially stacked. The first electrode sheet and the second electrode sheet have opposite polarities. The first electrode sheet comprises a first current collector and a first active material layer, the first active material layer being disposed on the side of the first current collector facing the solid electrolyte layer. The electrode assembly further includes a first hybrid layer disposed between the first active material layer and the solid electrolyte layer. The first hybrid layer comprises a first portion made of the same material as the first active material layer and a second portion made of the same material as the solid electrolyte layer. The first portion is connected to the first active material layer, the second portion is connected to the solid electrolyte layer, and the first portion and the second portion are interlocked with each other. The first hybrid layer can improve the charging and discharging capability of the battery cell.

Description

Battery cells, battery packs and electrical devices Cross-references to related applications

[0001] This application claims priority to Chinese patent application 202422611297.7, filed on October 28, 2024, entitled “Battery cell, battery device and power consumption device”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery technology, and in particular to a battery cell, battery device, and power supply device. Background Technology

[0003] Energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. For electric vehicles, battery technology is a crucial factor in their development.

[0004] Battery devices are widely used in portable electronic devices, electric vehicles, power tools, drones, energy storage devices, and other fields. A battery device consists of individual battery cells, and the charge / discharge capacity of these cells affects the battery's performance. Therefore, improving the charge / discharge capacity of batteries is a critical technical problem that needs to be solved in battery technology. Summary of the Invention

[0005] This application provides a battery cell, a battery device, and an electrical device that can improve the charging and discharging capability of the battery cell.

[0006] In a first aspect, embodiments of this application provide a battery cell, including a casing and an electrode assembly; the electrode assembly is housed within the casing, and includes a first electrode, a solid electrolyte layer, and a second electrode stacked together, the first electrode and the second electrode having opposite polarities, the solid electrolyte layer being disposed between the first electrode and the second electrode, the first electrode including a first current collector and a first active material layer, the first active material layer being disposed on the side of the first current collector facing the solid electrolyte layer; wherein, the electrode assembly further includes a first mixing layer, the first mixing layer being disposed between the first active material layer and the solid electrolyte layer, the first mixing layer including a first portion of the same material as the first active material layer and a second portion of the same material as the solid electrolyte layer, the first portion being connected to the first active material layer, the second portion being connected to the solid electrolyte layer, and the first portion and the second portion being interlocked with each other.

[0007] In the above technical solution, by setting the first active material layer to be of the same material as the first part and connecting the first active material layer and the first part, the first active material layer can transport ions through the outer surface of the first part. By setting the solid electrolyte layer to be of the same material as the second part and connecting the solid electrolyte layer and the second part, the solid electrolyte layer can transport ions through the outer surface of the second part. By setting the first part and the second part to be interlocked, the outer surfaces of the first part and the second part are in contact, so as to form more ion channels between the outer surfaces of the first part and the second part. This allows more ions to be inserted or extracted between the solid electrolyte layer and the first active material layer, improving the charge and discharge performance of the electrode assembly, thereby improving the charge and discharge capability of the battery cell.

[0008] In some embodiments, the thickness of the first mixing layer is 0.5 μm-10 μm. When the thickness of the first mixing layer is greater than or equal to 0.5 μm, the first mixing layer can provide more ion channels to the first active material layer and the solid electrolyte layer, which is beneficial to improving the charge and discharge capability of the battery cell. When the thickness of the first mixing layer is less than or equal to 10 μm, the space occupied by the first mixing layer in the electrode assembly can be reduced, which is beneficial to reducing the impact of the first mixing layer on the energy density of the electrode assembly. Therefore, when the thickness of the first mixing layer is 0.5 μm-10 μm, it is possible to balance increasing the ion channels between the first active material layer and the solid electrolyte layer and reducing the impact of the first mixing layer on the energy density of the electrode assembly.

[0009] In some embodiments, the first portion is connected to the solid electrolyte layer. Thus, the first portion connects the solid electrolyte layer and the first active material layer, providing a stable ion channel to both the first active material layer and the solid electrolyte layer, thereby making the charge and discharge capabilities of the battery cell more stable.

[0010] In some embodiments, the second portion is connected to the first active material layer. Thus, the second portion connects the first active material layer and the solid electrolyte layer, providing a stable ion channel to both the solid electrolyte layer and the first active material layer, thereby making the charge and discharge capabilities of the battery cell more stable.

[0011] In some embodiments, the first portion is connected to the solid electrolyte layer; the second portion is connected to the first active material layer. Thus, both the first and second portions are connected to the solid electrolyte layer and the first active material layer, and both can form stable ion channels between them. Furthermore, the first and second portions are interlocked, and the contact area between them can also form ion channels, thereby facilitating the insertion and extraction of ions between the solid electrolyte layer and the first active material layer, and improving the charge and discharge capability of the battery cell.

[0012] In some embodiments, along the thickness direction of the solid electrolyte layer, the second portion has a first surface and a second surface disposed opposite to each other; the second portion is provided with a first through hole, the two ends of the first through hole extending to the first surface and the second surface respectively, and the first portion includes a first fitting portion, at least a portion of the first fitting portion being fitted into the first through hole. On the one hand, by providing a first through hole in the second portion, the mutual fitting of the second portion and the first portion is made more convenient, reducing the processing cost of the first hybrid layer; on the other hand, by providing a first through hole in the second portion and fitting at least a portion of the first fitting portion into the first through hole, the amount of the first portion of the first active material layer can be increased, thereby improving the energy density of the battery cell.

[0013] In some embodiments, the first fitting portion is entirely fitted within the first through hole. This first through hole restricts the position of the first fitting portion, making the placement of the first portion more stable.

[0014] In some embodiments, there are multiple first through holes, which are spaced apart; there are multiple first fitting portions, each corresponding to a first through hole. By providing multiple first through holes and embedding a first fitting portion in each first through hole, the ion channels between the first active material layer and the solid electrolyte layer can be increased, thereby enabling more ions to be inserted or extracted between the solid electrolyte layer and the first active material layer, improving the charge and discharge performance of the electrode assembly, and thus improving the charge and discharge capability of the battery cell.

[0015] In some embodiments, within the same first mixed layer, the cross-sectional area of ​​the first portion is S1, the cross-sectional area of ​​the second portion is S2, and 0.05≤S1 / (S1+S2)≤0.95, the cross-section of the first mixed layer is perpendicular to the thickness direction of the solid electrolyte layer. When S1 / (S1+S2)≥0.05, the first mixed layer can have a sufficient first portion, thereby increasing the material used in the first active material layer of the electrode assembly and improving the energy density of the electrode assembly; when S1 / (S1+S2)≤0.95, the first mixed layer can have a sufficient second portion, thereby enhancing the ion-conducting ability of the first mixed layer; therefore, when 0.05≤S1 / (S1+S2)≤0.95, both the energy density of the electrode assembly and the ion-conducting ability of the first mixed layer can be balanced, enhancing the performance of the first mixed layer.

[0016] In some embodiments, 0.2 ≤ S1 / (S1+S2) ≤ 0.6. When S1 / (S1+S2) ≥ 0.2, the first mixed layer can have more of the first portion, thereby further increasing the use of material in the first active material layer of the electrode assembly and improving the energy density of the electrode assembly; when S1 / (S1+S2) ≤ 0.6, the first mixed layer can have more of the second portion, thereby further enhancing the ion-conducting ability of the first mixed layer; therefore, when 0.05 ≤ S1 / (S1+S2) ≤ 0.95, the energy density of the electrode assembly and the ion-conducting ability of the first mixed layer can be further balanced, enhancing the performance of the first mixed layer.

[0017] In some embodiments, the first portion is integrally formed with the first active material layer. This makes the processing of the first portion and the first active material layer easier, and the connection between the first portion and the first active material layer is tighter, which is beneficial for electron transport between the first portion and the first active material layer.

[0018] In some embodiments, the second portion and the solid electrolyte layer are integrally formed. This makes the processing of the first portion and the solid electrolyte layer easier; on the other hand, the connection between the second portion and the solid electrolyte layer is more stable, which is beneficial for ion conduction between the solid electrolyte layer and the first active material layer.

[0019] In some embodiments, the first portion is integrally formed with the first active material layer, and the second portion is integrally formed with the solid electrolyte layer. This makes the electrode assembly easier to process; furthermore, it enhances the conductivity between the first mixed layer and the first active material layer, as well as the ion conductivity between the first mixed layer and the solid electrolyte layer, and increases the ion channels between the solid electrolyte layer and the first active material layer, thereby improving the charge / discharge capability of the battery cell.

[0020] In some embodiments, the thickness of the solid electrolyte layer is greater than or equal to the thickness of the first hybrid layer. This results in a thicker solid electrolyte layer, enhancing the structural strength of the electrode assembly and reducing the risk of the solid electrolyte layer being punctured.

[0021] In some embodiments, a first active material layer is disposed on both opposite sides of the first current collector. A first mixed layer is disposed between the first active material layer on one side of the first current collector and a solid electrolyte layer, and a first mixed layer is disposed between the first active material layer on the other side of the first current collector and another solid electrolyte layer. By disposing a first active material layer on both opposite sides of the first current collector, and by disposing a first mixed layer between each of the two active material layers and its corresponding solid electrolyte layer, the ion channels between the first active material layer and the solid electrolyte layer are increased, thereby further enhancing the charge and discharge capability of the electrode assembly.

[0022] In some embodiments, the second electrode includes a second current collector and a second active material layer, with the second active material layer disposed on the side of the second current collector facing the solid electrolyte layer. The electrode assembly also includes a second mixing layer disposed between the second active material layer and the solid electrolyte layer. The second mixing layer includes a third portion of the same material as the second active material layer and a fourth portion of the same material as the solid electrolyte layer. The third portion is connected to the second active material layer, and the fourth portion is connected to the solid electrolyte layer, with the third and fourth portions interlocked. By making the second active material layer and the third portion of the same material and connecting them, the second active material layer can transport ions through the outer surface of the third portion. By making the solid electrolyte layer and the fourth portion of the same material and connecting them, the solid electrolyte layer can transport ions through the outer surface of the fourth portion. By interlocking the third and fourth portions, the outer surfaces of the third and fourth portions are in contact, forming more ion channels between them. This allows more ions to be inserted or extracted between the solid electrolyte layer and the second active material layer, improving the charge-discharge performance of the electrode assembly and thus enhancing the charge-discharge capability of the battery cell.

[0023] In some embodiments, the thickness of the second mixing layer is 0.5 μm-10 μm. When the thickness of the second mixing layer is greater than or equal to 0.5 μm, the second mixing layer can provide more ion channels to the second active material layer and the solid electrolyte layer, which is beneficial to improving the charge and discharge capability of the battery cell. When the thickness of the second mixing layer is less than or equal to 10 μm, the space occupied by the second mixing layer in the electrode assembly can be reduced, which is beneficial to reducing the impact of the second mixing layer on the energy density of the electrode assembly. Therefore, when the thickness of the second mixing layer is 0.5 μm-10 μm, it is possible to balance increasing the ion channels between the second active material layer and the solid electrolyte layer and reducing the impact of the second mixing layer on the energy density of the electrode assembly.

[0024] In some embodiments, the third portion is connected to the solid electrolyte layer. Thus, the third portion connects the solid electrolyte layer and the second active material layer, providing a stable ion channel to both the second active material layer and the solid electrolyte layer, resulting in more stable charge and discharge capabilities of the battery cell.

[0025] In some embodiments, the fourth portion is connected to the second active material layer. Thus, the fourth portion connects the second active material layer and the solid electrolyte layer, providing a stable ion channel to both the solid electrolyte layer and the second active material layer, thereby making the charge and discharge capabilities of the battery cell more stable.

[0026] In some embodiments, the third portion is connected to the solid electrolyte layer, and the fourth portion is connected to the second active material layer. Thus, both the third and fourth portions are connected to the solid electrolyte layer and the second active material layer, and both can form stable ion channels between them. Furthermore, the third and fourth portions are interlocked, and the contact area between them can also form ion channels, thereby facilitating the insertion and extraction of ions between the solid electrolyte layer and the second active material layer, and improving the charge and discharge capability of the battery cell.

[0027] In some embodiments, along the thickness direction of the solid electrolyte layer, the fourth portion has a third surface and a fourth surface disposed opposite to each other; the fourth portion is provided with a second through hole, the two ends of the second through hole extending to the third surface and the fourth surface respectively, and the third portion includes a second fitting portion, at least a portion of which is fitted into the second through hole. On the one hand, by providing a second through hole in the fourth portion, the mutual fitting of the fourth portion and the third portion is made more convenient, reducing the processing cost of the second hybrid layer; on the other hand, by providing a second through hole in the fourth portion and fitting at least a portion of the second fitting portion into the second through hole, the amount of the third portion of the second active material layer can be increased, thereby improving the energy density of the battery cell.

[0028] In some embodiments, the second fitting portion is entirely fitted within the second through hole. This second through hole restricts the placement position of the third portion, making its placement more stable.

[0029] In some embodiments, there are multiple second through holes, which are spaced apart; there are multiple second fitting portions, each corresponding to a second through hole. By providing multiple second through holes and embedding a second fitting portion in each second through hole, the ion channels between the second active material layer and the solid electrolyte layer can be increased, thereby enabling more ions to be inserted or extracted between the solid electrolyte layer and the second active material layer, improving the charge and discharge performance of the electrode assembly, and thus enhancing the charge and discharge capability of the battery cell.

[0030] In some embodiments, within the same cross-section of the second mixed layer, the cross-sectional area of ​​the third portion is S3, the cross-sectional area of ​​the fourth portion is S4, and 0.05≤S3 / (S3+S4)≤0.95, the cross-section of the second mixed layer is perpendicular to the thickness direction of the solid electrolyte layer. When S3 / (S3+S4)≥0.05, the second mixed layer can have a sufficient third portion, thereby increasing the material used in the second active material layer of the electrode assembly and improving the energy density of the electrode assembly; when S3 / (S3+S4)≤0.95, the second mixed layer can have a sufficient fourth portion, thereby enhancing the ion-conducting ability of the second mixed layer; therefore, when 0.05≤S3 / (S3+S4)≤0.95, the energy density of the electrode assembly and the ion-conducting ability of the second mixed layer can be balanced, enhancing the performance of the second mixed layer.

[0031] In some embodiments, 0.2 ≤ S3 / (S3+S4) ≤ 0.6. When S3 / (S3+S4) ≥ 0.2, the second mixed layer can have more third portions, thereby further increasing the use of material in the second active material layer of the electrode assembly and improving the energy density of the electrode assembly; when S3 / (S3+S4) ≤ 0.6, the second mixed layer can have more fourth portions, thereby further enhancing the ion-conducting ability of the second mixed layer; therefore, when 0.05 ≤ S3 / (S3+S4) ≤ 0.95, the energy density of the electrode assembly and the ion-conducting ability of the second mixed layer can be further balanced, enhancing the performance of the second mixed layer.

[0032] In some embodiments, the third portion is integrally formed with the second active material layer. This makes the processing of the third portion and the second active material layer easier, and the connection between the third portion and the second active material layer is tighter, which is beneficial for electron transport between the third portion and the second active material layer.

[0033] In some embodiments, the fourth part and the solid electrolyte layer are integrally formed. This makes the processing of the third part and the solid electrolyte layer easier; on the other hand, the connection between the fourth part and the solid electrolyte layer is more stable, which is beneficial for ion conduction between the solid electrolyte layer and the second active material layer.

[0034] In some embodiments, the third portion is integrally formed with the second active material layer, and the fourth portion is integrally formed with the solid electrolyte layer. This makes the electrode assembly easier to process; furthermore, it enhances the conductivity between the second mixed layer and the second active material layer, as well as the ion conductivity between the second mixed layer and the solid electrolyte layer, and increases the ion channels between the solid electrolyte layer and the second active material layer, thereby improving the charge / discharge capacity of the battery cell.

[0035] In some embodiments, the thickness of the solid electrolyte layer is greater than or equal to the thickness of the second hybrid layer. This results in a thicker solid electrolyte layer, enhancing the structural strength of the electrode assembly and reducing the risk of the solid electrolyte layer being punctured.

[0036] Secondly, embodiments of this application provide a battery device, including the battery cell provided in any one of the embodiments of the first aspect.

[0037] Thirdly, embodiments of this application provide an electrical device, including a battery cell provided in any one of the embodiments of the first aspect or a battery device provided in any one of the embodiments of the second aspect, wherein the battery cell is used to provide electrical energy to the electrical device.

[0038] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0039] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0040] Figure 1 is a structural schematic diagram of a vehicle provided in some embodiments of this application;

[0041] Figure 2 is an exploded view of a battery device provided in some embodiments of this application;

[0042] Figure 3 is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0043] Figure 4 is a magnified view of a portion of region A in Figure 3;

[0044] Figure 5 is a partial structural diagram of the first and second parts provided in some embodiments of this application;

[0045] Figure 6 is a partial structural diagram of the first and second parts provided in some other embodiments of this application;

[0046] Figure 7 is a schematic diagram of the structure of the first hybrid layer provided in some embodiments of this application;

[0047] Figure 8 is a schematic diagram of the structure of an electrode assembly provided in some embodiments of this application;

[0048] Figure 9 is a BB cross-sectional view of Figure 8;

[0049] Figure 10 is a schematic diagram of the structure of an electrode assembly provided in some embodiments of this application;

[0050] Figure 11 is a magnified view of region C in Figure 3;

[0051] Figure 12 is a DD cross-sectional view of Figure 8. Labeling: 1-Electrode assembly; 11-First electrode; 111-First current collector; 112-First active material layer; 12-Solid electrolyte layer; 13-Second electrode; 131-Second current collector; 132-Second active material layer; 14-First mixing layer; 141-First part; 1411-First mating part; 142-Second part; 1421-First surface; 1422-Second surface; 1423-First through hole; 15-Second mixing layer; 151-Third part; 1511-Second mating part; 152-Fourth part; 1521-Third surface; 1522-Fourth surface; 1523-Second through hole; 2-Outer casing; 10-Battery cell; 20-Casing; 201-First casing; 202-Second casing; 100-Battery device; 200-Controller; 300-Motor; 1000-Vehicle. Detailed Implementation

[0052] The embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of this application by way of example, but should not be used to limit the scope of this application, that is, this application is not limited to the described embodiments.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0054] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly indicating the number, specific order, or primary and secondary relationship of the indicated technical features.

[0055] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0056] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces), unless otherwise explicitly specified.

[0057] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0058] In this application, "multiple" refers to two or more (including two), and similarly, "multiple groups" refers to two or more (including two), and "multiple pieces" refers to two or more (including two).

[0059] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0060] Battery cells include, but are not limited to, lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc.

[0061] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, reduces the risk of short circuits while allowing active ions to pass through.

[0062] In some embodiments, the positive electrode can be a positive electrode sheet, which may include a positive current collector and a positive active material disposed on at least one surface of the positive current collector.

[0063] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0064] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0065] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials in battery cells may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium manganese iron phosphate, and lithium manganese iron phosphate and carbon composites. Examples of lithium transition metal oxides may include, but are not limited to, at least one of lithium cobalt oxides (such as LiCoO2), lithium nickel oxides (such as LiNiO2), lithium manganese oxides (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxides, lithium manganese cobalt oxides, lithium nickel manganese oxides, lithium nickel cobalt manganese oxides (such as LiNi1 / 3Co1 / 3Mn1 / 3O2 (also abbreviated as NCM333), LiNi0.5Co0.2Mn0.3O2 (also abbreviated as NCM523), LiNi0.5Co0.25Mn0.25O2 (also abbreviated as NCM211), LiNi0.6Co0.2Mn0.2O2 (also abbreviated as NCM622), LiNi0.8Co0.1Mn0.1O2 (also abbreviated as NCM811), lithium nickel cobalt aluminum oxides (such as LiNi0.85Co0.15Al0.05O2)) and their modified compounds.

[0066] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloys, etc. When foamed metal is used as the positive electrode, the surface of the foamed metal may or may not contain a positive electrode active material. As an example, lithium source material, potassium metal, or sodium metal can also be filled and / or deposited within the foamed metal, where the lithium source material is lithium metal and / or a lithium-rich material.

[0067] In some embodiments, the negative electrode can be a negative electrode sheet, and the negative electrode sheet can include a negative current collector.

[0068] As an example, the negative electrode current collector can be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium, etc. Foamed metal can be nickel foam, copper foam, aluminum foam, foam alloy, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0069] As an example, the negative electrode sheet may include a negative current collector and a negative active material disposed on at least one surface of the negative current collector.

[0070] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0071] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials in battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0072] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0073] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0074] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0075] As an example, polymer solid electrolytes can be polyether (polyoxyethylene), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids-lithium salts, cellulose, etc.

[0076] As an example, inorganic solid electrolytes may include one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphate sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0077] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0078]

[0079] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing may be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0080] As an example, a battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic battery cells, such as hexagonal prismatic battery cells.

[0081] The battery apparatus mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0082] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module, which is formed by arranging multiple battery cells and fixing them together to form an independent module.

[0083] As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0084] In some embodiments, the battery device may be a battery pack, which may include a housing and one or more individual battery cells housed within the housing.

[0085] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0086] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0087] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0088] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0089] As an example, the housing can be part of the vehicle's chassis structure. For instance, the housing's roof can be at least part of the vehicle's floor, or the housing's frame can be at least part of the vehicle's crossbeams and longitudinal beams.

[0090] In some embodiments, the battery device refers to an energy storage device, which includes a housing with a door on at least one side. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0091] For a typical battery cell, the battery cell may include a casing and an electrode assembly. The electrode assembly is housed within the casing and may include a first electrode, a separator, and a second electrode. The first electrode and the second electrode have opposite polarities. The separator is disposed between the first electrode and the second electrode to separate them. The first electrode includes a first current collector and a first active material layer. Ion exchange between the first active material layer and the separator is achieved through the interface between them.

[0092] In a solid-state battery cell, the solid electrolyte layer serves as a separator between the first and second electrodes. Ion exchange between the solid electrolyte layer and the first active material layer occurs through the solid-solid interface between them. The contact area of ​​this interface directly affects ion transport between the solid electrolyte layer and the first active material layer, thus influencing the charge-discharge capability of the battery cell. However, the solid-solid interface between the solid electrolyte layer and the first active material layer suffers from a small interface area, resulting in a small contact area and consequently impacting the charge-discharge capability of the battery cell.

[0093] In view of this, this application provides a battery cell, which includes a casing and an electrode assembly. The electrode assembly is housed within the casing and includes a first electrode, a solid electrolyte layer, and a second electrode stacked together. The first electrode and the second electrode have opposite polarities. The solid electrolyte layer is disposed between the first electrode and the second electrode. The first electrode includes a first current collector and a first active material layer. The first active material layer is disposed on the side of the first current collector facing the solid electrolyte layer. The electrode assembly also includes a first mixing layer, which is disposed between the first active material layer and the solid electrolyte layer. The first mixing layer includes a first portion of the same material as the first active material layer and a second portion of the same material as the solid electrolyte layer. The first portion is connected to the first active material layer, and the second portion is connected to the solid electrolyte layer. The first portion and the second portion are interlocked.

[0094] In such a battery cell, by interlocking a first part made of the same material as the first active material layer and a second part made of the same material as the solid electrolyte layer, an ion channel can be formed between the solid electrolyte layer and the first active material layer at the contact interface between the first part and the second part, thereby improving the charge and discharge capability of the battery cell.

[0095] For ease of explanation, the following embodiments will use a vehicle 1000 as an example of electrical equipment.

[0096] Please refer to Figure 1, which is a structural schematic diagram of a vehicle 1000 provided in some embodiments of this application. A battery device 100 is disposed inside the vehicle 1000, and the battery device 100 may be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000.

[0097] The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, for the power needs of the vehicle 1000 during startup, navigation and driving.

[0098] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0099] Please refer to Figure 2, which is an exploded view of a battery device 100 provided in some embodiments of this application. The battery device 100 may include a housing 20 and battery cells 10, with the housing 20 used to house the battery cells 10.

[0100] The housing 20 has an enclosed space inside for accommodating the battery cells 10. The housing 20 can have various structures. In some embodiments, the housing 20 may include a first housing 201 and a second housing 202, which are interlocked. The first housing 201 and the second housing 202 can have various shapes, such as cuboids or cylinders. The first housing 201 can be a hollow structure open on one side, and the second housing 202 can also be a hollow structure open on one side. The open side of the second housing 202 interlocks with the open side of the first housing 201, thus forming a housing 20 with an enclosed space. Alternatively, the first housing 201 can be a hollow structure open on one side, and the second housing 202 can be a plate-like structure, with the second housing 202 interlocked with the open side of the first housing 201, thus forming a housing 20 with an accommodating space.

[0101] In the battery device 100, there can be one or more battery cells 10. If there are multiple battery cells 10, they can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 10 are connected in both series and parallel. Alternatively, multiple battery cells 10 can be first connected in series, parallel, or in a mixed manner to form a battery module, and then multiple battery modules can be connected in series, parallel, or in a mixed manner to form a whole, which is then housed within the housing 20. Another option is that all battery cells 10 can be directly connected in series, parallel, or in a mixed manner, and then the whole consisting of all battery cells 10 is housed within the housing 20.

[0102] Please refer to Figures 3 and 4. Figure 3 is a structural schematic diagram of a battery cell 10 provided in some embodiments of this application; Figure 4 is a partial enlarged view of region A in Figure 3. This application provides a battery cell 10, including a housing 2 and an electrode assembly 1. The electrode assembly 1 is housed within the housing 2. The electrode assembly 1 includes a first electrode 11, a solid electrolyte layer 12, and a second electrode 13 stacked together. The first electrode 11 and the second electrode 13 have opposite polarities. The solid electrolyte layer 12 is disposed between the first electrode 11 and the second electrode 13. The first electrode 11 includes a first current collector 111 and a first active material layer 112. The first active material layer 112 is disposed on the side of the first current collector 111 facing the solid electrolyte layer 12. The electrode assembly 1 further includes a first mixing layer 14, which is disposed between the first active material layer 112 and the solid electrolyte layer 12. The first mixing layer 14 includes a first part 141 made of the same material as the first active material layer 112 and a second part 142 made of the same material as the solid electrolyte layer 12. The first part 141 is connected to the first active material layer 112, and the second part 142 is connected to the solid electrolyte layer 12. The first part 141 and the second part 142 are interlocked with each other.

[0103] The first electrode 11 can be the positive electrode, the second electrode 13 can be the negative electrode, and the first active material layer 112 can be the positive active material; or the first electrode 11 can be the negative electrode, the second electrode 13 can be the positive electrode, and the first active material layer 112 can be the negative active material.

[0104] It is possible that only a portion of the solid electrolyte layer 12 is disposed between the first electrode 11 and the second electrode 13; or it is possible that the entire solid electrolyte layer 12 is disposed between the first electrode 11 and the second electrode 13.

[0105] The first active material layer 112 may be provided on only one side of the first current collector 111, and a solid electrolyte layer 12 may be provided on the side of the first active material layer 112 facing away from the first current collector 111; or the first active material layer 112 may be provided on both opposite sides of the first current collector 111, and a solid electrolyte layer 12 may be provided on the side of one first active material layer 112 facing away from the first current collector 111; and a solid electrolyte layer 12 may also be provided on the side of the other first active material layer 112 facing away from the first current collector 111.

[0106] The first mixing layer 14 is disposed between the first active material layer 112 and the solid electrolyte layer 12 to connect the first active material layer 112 and the solid electrolyte layer 12. The first mixing layer 14, the first active material layer 112, and the solid electrolyte layer 12 can be separately arranged and connected, wherein the first part 141 and the second part 142 are interlocked to form the first mixing layer 14; or the first active material layer 112 and the first part 141 can be integrally formed, and the solid electrolyte layer 12 and the second part 142 can be separately arranged and connected, with the first part 141 and the second part 142 interlocked to form the first mixing layer 14; or the first active material layer 112 and the first part 141 can be separately arranged and connected, and the solid electrolyte layer 12 and the second part 142 can be integrally formed, with the first part 141 and the second part 142 interlocked to form the first mixing layer 14; or the first active material layer 112 and the first part 141 can be integrally formed, and the solid electrolyte layer 12 and the second part 142 can be integrally formed, with the first part 141 and the second part 142 interlocked to form the first mixing layer 14.

[0107] The first active material layer 112 and the first part 141 are made of the same material, and the solid electrolyte layer 12 and the second part 142 are made of the same material.

[0108] The first part 141 and the second part 142 can be fitted together, where at least a portion of the first part 141 is embedded in the second part 142; at least a portion of the second part 142 is embedded in the first part 141; or at least a portion of the first part 141 is embedded in the second part 142, and at least a portion of the second part 142 is embedded in the first part 141. For example, the first part 141 has a groove structure on the side facing the solid electrolyte layer 12, and at least a portion of the second part 142 is embedded in the groove structure, so that the surface of the groove structure of the first part 141 is in contact with the surface of the portion of the second part 142 embedded in the groove structure; or, for another example, the first part 141 has a hole structure on the side facing the solid electrolyte layer 12, and at least a portion of the second part 142 is embedded in the hole structure, so that the surface of the hole structure of the first part 141 is in contact with the surface of the portion of the second part 142 embedded in the hole structure.

[0109] In this embodiment, by setting the first active material layer 112 to be made of the same material as the first portion 141, and connecting the first active material layer 112 and the first portion 141, the first active material layer 112 can transport ions through the outer surface of the first portion 141. By setting the solid electrolyte layer 12 to be made of the same material as the second portion 142, and connecting the solid electrolyte layer 12 and the second portion 142, the solid electrolyte layer 12 can transport ions through the outer surface of the second portion 142. By setting the first portion 141 and the second portion 142 to be interlocked, the outer surfaces of the first portion 141 and the second portion 142 are in contact, thereby forming more ion channels between the outer surfaces of the first portion 141 and the second portion 142. This allows more ions to be inserted or extracted between the solid electrolyte layer 12 and the first active material layer 112, improving the charge and discharge performance of the electrode assembly 1, and thus improving the charge and discharge capability of the battery cell 10. Furthermore, the first part 141 and the second part 142 are interlocked with each other, which on the one hand increases the contact area between the active material and the solid electrolyte, and increases the ion channel between the first active material layer 112 and the solid electrolyte layer 12; on the other hand, the connection between the first part 141 and the second part 142 is more stable, making the structure of the ion channel more stable, thereby enabling a stable improvement in the charging and discharging capacity of the battery cell 10.

[0110] In some embodiments, please refer to Figures 3 and 4. The thickness of the first hybrid layer 14 is 0.5 μm-10 μm.

[0111] The first active material layer 112, the first mixing layer 14, and the solid electrolyte layer 12 are stacked along the thickness direction of the solid electrolyte layer 12. The thickness of the first mixing layer 14 is the dimension of the first mixing layer 14 in the thickness direction of the solid electrolyte layer 12. The thickness of the first mixing layer 14 can be any one of 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm, 1μm, 15μm, 2μm, 2.5μm, 3μm, 3.5μm, 4μm, 4.5μm, 5μm, 5.5μm, 6μm, 6.5μm, 7μm, 7.5μm, 8μm, 8.5μm, 9μm, 9.5μm, and 1μm, or a range between any two.

[0112] When the thickness of the first mixing layer 14 is greater than or equal to 0.5 μm, the first mixing layer 14 can provide more ion channels to the first active material layer 112 and the solid electrolyte layer 12, which is beneficial to improving the charge and discharge capability of the battery cell 10. When the thickness of the first mixing layer 14 is less than or equal to 10 μm, the space occupied by the first mixing layer 14 in the electrode assembly 1 can be reduced, which is beneficial to reducing the impact of the first mixing layer 14 on the energy density of the electrode assembly 1. Therefore, when the thickness of the first mixing layer 14 is 0.5 μm-10 μm, it is possible to balance increasing the ion channels between the first active material layer 112 and the solid electrolyte layer 12 and reducing the impact of the first mixing layer 14 on the energy density of the electrode assembly 1.

[0113] In some embodiments, please refer to Figures 4-6. Figure 5 is a partial structural schematic diagram of the first part 141 and the second part 142 provided in some embodiments of this application; Figure 6 is a partial structural schematic diagram of the first part 141 and the second part 142 provided in other embodiments of this application. The first part 141 is connected to the solid electrolyte layer 12.

[0114] The first part 141 may abut against the solid electrolyte layer 12, thereby connecting the first part 141 to the solid electrolyte layer 12; or the first part 141 may be bonded to the solid electrolyte layer 12, thereby connecting the first part 141 to the solid electrolyte layer 12.

[0115] The second part 142 can be directly connected to the first active material layer 112; or the second part 142 can be indirectly connected to the first active material layer 112, for example, the second part 142 is connected to the first active material layer 112 through the first part 141.

[0116] In this embodiment, the first part 141 connects the solid electrolyte layer 12 and the first active material layer 112. The first part 141 can provide a stable ion channel to the first active material layer 112 and the solid electrolyte layer 12, making the charge and discharge capability of the battery cell 10 more stable.

[0117] In some embodiments, please continue to refer to Figures 4 and 6. The second portion 142 is connected to the first active material layer 112.

[0118] The second part 142 may abut against the first active material layer 112, so that the second part 142 is connected to the first active material layer 112; or the second part 142 may be bonded to the first active material layer 112, so that the second part 142 is connected to the first active material layer 112.

[0119] The first part 141 can be directly connected to the solid electrolyte layer 12; or the first part 141 can be indirectly connected to the solid electrolyte layer 12, for example, the first part 141 can be connected to the first active material layer through the second part 142.

[0120] In this embodiment, the second part 142 connects the first active material layer 112 and the solid electrolyte layer 12. The second part 142 can provide a stable ion channel to the solid electrolyte layer 12 and the first active material layer 112, making the charge and discharge capability of the battery cell 10 more stable.

[0121] In some embodiments, please continue to refer to Figure 4. The first portion 141 is connected to the solid electrolyte layer 12, and the second portion 142 is connected to the first active material layer 112.

[0122] The region where the first part 141 is connected to the solid electrolyte layer 12, the region where the second part 142 is connected to the first active material layer 112, and the contact region between the first part 141 and the second part 142 can all form ion channels between the solid electrolyte layer 12 and the first active material layer 112.

[0123] In this embodiment, both the first part 141 and the second part 142 are connected to the solid electrolyte layer 12 and the first active material layer 112. Both the first part 141 and the second part 142 can form a stable ion channel between the solid electrolyte layer 12 and the first active material layer 112. Furthermore, the first part 141 and the second part 142 are interlocked, and the area where the first part 141 and the second part 142 are in contact can also form an ion channel. This facilitates the insertion or extraction of ions between the solid electrolyte layer 12 and the first active material layer 112, thereby improving the charge and discharge capability of the battery cell 10.

[0124] In some embodiments, please refer to Figures 4 and 7. Figure 7 is a schematic diagram of the structure of the first mixing layer 14 provided in some embodiments of this application. Along the thickness direction of the solid electrolyte layer 12, the second portion 142 has a first surface 1421 and a second surface 1422 disposed opposite to each other. The second portion 142 is provided with a first through hole 1423, the two ends of the first through hole 1423 extending to the first surface 1421 and the second surface 1422 respectively. The first portion 141 includes a first fitting portion 1411, at least a portion of the first fitting portion 1411 being fitted into the first through hole 1423.

[0125] Both the first surface 1421 and the second surface 1422 can be planar or curved. The extension of both ends of the first through hole 1423 to the first surface 1421 and the second surface 1422 means that the first through hole 1423 penetrates the second part 142.

[0126] The first through hole 1423 can be one or more. In an embodiment where there is one first through hole 1423, the entire first fitting part 1411 can be fitted into the first through hole 1423; or only a portion of the first fitting part 1411 can be fitted into the first through hole 1423. In an embodiment where there are multiple first through holes 1423, only a portion of the multiple first through holes 1423 can have the first fitting part 1411 fitted into them; or each first through hole 1423 can have the first fitting part 1411 fitted into it.

[0127] The first fitting part 1411 may be entirely contained within the first through hole 1423, or only a portion of the first fitting part 1411 may be contained within the first through hole 1423.

[0128] In this embodiment, on the one hand, by providing a first through hole 1423 in the second part 142, the mutual fitting of the second part 142 and the first part 141 is made more convenient, and the processing cost of the first hybrid layer 14 is reduced; on the other hand, by providing a first through hole 1423 in the second part 142 and embedding at least a portion of the first fitting part 1411 in the first through hole 1423, the amount of the first part 141 of the first active material layer 112 can be increased, thereby improving the energy density of the battery cell 10.

[0129] In some embodiments, please continue to refer to Figures 4 and 7. The first fitting portion 1411 is entirely fitted into the first through hole 1423.

[0130] In an embodiment where there is one first through hole 1423, the first fitting part 1411 may be entirely fitted into one first through hole 1423. In an embodiment where there are multiple first through holes 1423, the first fitting part 1411 may be entirely fitted into only a portion of the multiple first through holes 1423; or the first fitting part 1411 may be entirely fitted into each of the multiple first through holes 1423.

[0131] In this embodiment, the first through-hole 1423 restricts the placement of the first fitting portion 1411, making the placement of the first portion 141 more stable. In embodiments where the first portion 141 only includes the first fitting portion 1411, the first fitting portion 1411 is entirely embedded within the first through-hole 1423, allowing the surface of the second portion 142 facing the first active material layer 112 to directly contact the first active material layer 112 to form an ion channel. The portion where the first fitting portion 1411 and the second portion 142 contact can also form an ion channel, thereby increasing the ion channels between the first active material layer 112 and the solid electrolyte layer 12. Such a first mixed layer 14 is easy to process, has low processing cost, and improves the charge and discharge capability of the battery cell 10.

[0132] In some embodiments, please refer to Figure 7. There are multiple first through holes 1423, which are spaced apart; there are multiple first fitting portions 1411, which correspond one-to-one with the first through holes 1423.

[0133] As an example, as shown in Figure 7, the first through holes 1423 are arranged in multiple rows and columns, and each first through hole 1423 is embedded with a first fitting part 1411.

[0134] In this embodiment, by providing multiple first through holes 1423 and embedding a first fitting portion 1411 within each first through hole 1423, the ion channels between the first active material layer 112 and the solid electrolyte layer 12 can be increased. This allows more ions to be inserted or extracted between the solid electrolyte layer 12 and the first active material layer 112, improving the charge-discharge performance of the electrode assembly 1 and thus enhancing the charge-discharge capability of the battery cell 10. It is understood that the more first through holes 1423 there are, the larger the total area of ​​the hole walls of the first through holes 1423. When the first fitting portion 1411 contacts more hole walls of the first through holes 1423, more ion channels can be obtained between the first active material layer 112 and the solid electrolyte layer 12.

[0135] In some embodiments, please refer to Figures 8 and 9. Figure 8 is a structural schematic diagram of the electrode assembly 1 of the battery cell 10 provided in some embodiments of this application; Figure 9 is a BB cross-sectional view of Figure 8. Within the same first mixing layer 14, the cross-sectional area of ​​the first part 141 is S1, the cross-sectional area of ​​the second part 142 is S2, 0.05≤S1 / (S1+S2)≤0.95, and the cross-section of the first mixing layer 14 is perpendicular to the thickness direction of the solid electrolyte layer 12.

[0136] The cross-sectional area of ​​the first portion 141 refers to the total area of ​​the first portion 141 within the cross-section of the first hybrid layer 14. For example, if the first portion 141 includes only one first fitting part 1411, the cross-sectional area of ​​the first portion 141 is the area of ​​the first fitting part 1411 within the cross-section of the first hybrid layer 14; or if the first portion 141 includes multiple first fitting parts 1411, the cross-sectional area of ​​the first portion 141 is the sum of the areas of the multiple first fitting parts 1411 within the cross-section of the first hybrid layer 14. The cross-sectional area of ​​the second portion 142 refers to the area after subtracting the cross-sectional area of ​​the first portion 141 from the total cross-sectional area of ​​the first hybrid layer 14.

[0137] For example, the first part 141 has a plurality of first fitting portions 1411, and the sum of the cross-sectional areas of the plurality of first fitting portions 1411 is the cross-sectional area of ​​the first part 141.

[0138] The value of S1 / (S1+S2) can be any one of the following values: 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, or any value between two of them.

[0139] In this embodiment, when S1 / (S1+S2)≥0.05, the first mixed layer 14 can have a sufficient first portion 141, thereby increasing the material used in the first active material layer 112 in the electrode assembly 1 and improving the energy density of the electrode assembly 1; when S1 / (S1+S2)≤0.95, the first mixed layer 14 can have a sufficient second portion 142, thereby enhancing the ion-conducting ability of the first mixed layer 14; therefore, when 0.05≤S1 / (S1+S2)≤0.95, both the energy density of the electrode assembly 1 and the ion-conducting ability of the first mixed layer 14 can be balanced, enhancing the performance of the first mixed layer 14.

[0140] In some embodiments, 0.2 ≤ S1 / (S1+S2) ≤ 0.6.

[0141] The value of S1 / (S1+S2) can be any one of the following values ​​or any value between two of them: 0.2, 0.22, 0.24, 0.25, 0.26, 0.28, 0.3, 0.32, 0.34, 0.35, 0.36, 0.38, 0.4, 0.42, 0.44, 0.45, 0.46, 0.48, 0.5, 0.52, 0.54, 0.55, 0.56, 0.58, 0.6.

[0142] In this embodiment, when S1 / (S1+S2)≥0.2, the first mixed layer 14 can have more first portions 141, thereby further increasing the use of material in the first active material layer 112 in the electrode assembly 1 and improving the energy density of the electrode assembly 1; when S1 / (S1+S2)≤0.6, the first mixed layer 14 can have more second portions 142, thereby further enhancing the ion-conducting ability of the first mixed layer 14; therefore, when 0.05≤S1 / (S1+S2)≤0.95, the energy density of the electrode assembly 1 and the ion-conducting ability of the first mixed layer 14 can be further balanced, enhancing the performance of the first mixed layer 14.

[0143] In some embodiments, the first portion 141 and the first active material layer 112 are integrally formed. In this embodiment, on the one hand, the processing of the first portion 141 and the first active material layer 112 is more convenient; on the other hand, the connection between the first portion 141 and the first active material layer 112 is tighter, which is beneficial to the electron transport between the first portion 141 and the first active material layer 112.

[0144] In some embodiments, the second portion 142 and the solid electrolyte layer 12 are integrally formed. In this embodiment, on the one hand, the processing of the first portion 141 and the solid electrolyte layer 12 is more convenient; on the other hand, the connection between the second portion 142 and the solid electrolyte layer 12 is more stable, which is beneficial to the ion conduction between the solid electrolyte layer 12 and the first active material layer 112.

[0145] In some embodiments, the first portion 141 is integrally formed with the first active material layer 112, and the second portion 142 is integrally formed with the solid electrolyte layer 12. In this embodiment, on the one hand, the electrode assembly 1 is easier to process; on the other hand, it can improve the conductivity of electrons between the first mixed layer 14 and the first active material layer 112, improve the ion conductivity between the first mixed layer 14 and the solid electrolyte layer 12, and increase the ion channels between the solid electrolyte layer 12 and the first active material layer 112, thereby improving the charge and discharge capacity of the battery cell 10.

[0146] In some embodiments, the thickness of the solid electrolyte layer 12 is greater than or equal to the thickness of the first hybrid layer 14.

[0147] The thickness of the solid electrolyte layer 12 can be equal to or greater than the thickness of the first mixing layer 14. For example, the thickness of the first mixing layer 14 can be 10 μm. The thickness of the solid electrolyte layer 12 can be 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, etc.

[0148] In this embodiment, the solid electrolyte layer 12 has a relatively thick thickness, which improves the structural strength of the electrode assembly 1 and reduces the risk of the solid electrolyte layer 12 being broken down due to lithium plating.

[0149] In some embodiments, please refer to FIG10, which is a schematic diagram of the structure of an electrode assembly 1 provided in some embodiments of the present application. A first active material layer 112 is provided on both opposite sides of the first current collector 111. A first mixing layer 14 is provided between the first active material layer 112 on one side of the first current collector 111 and a solid electrolyte layer 12. A first mixing layer 14 is provided between the first active material layer 112 on the other side of the first current collector 111 and another solid electrolyte layer 12.

[0150] The electrode assembly 1 may have multiple solid electrolyte layers 12, with a first electrode 11 and a second electrode 13 disposed on both sides of each solid electrolyte layer 12. For example, each first electrode 11 has a first active material layer 112 disposed on both sides of its first current collector 111, and the two outermost electrodes of the electrode assembly 1 are the second electrodes 13. The first electrode 11 may be a positive electrode, and the second electrode 13 a negative electrode. Alternatively, the first electrode 11 may be a negative electrode, and the second electrode 13 a positive electrode.

[0151]

[0152] By providing a first active material layer 112 on both sides of the first current collector 111, and providing a first mixing layer 14 between each of the two active material layers and their corresponding solid electrolyte layer 12, the ion channels between the first active material layer 112 and the solid electrolyte layer 12 are increased, thereby further enhancing the charging and discharging capability of the electrode assembly 1.

[0153] In some embodiments, please refer to Figures 3 and 11, where Figure 11 is a partial enlarged view of region C in Figure 3. The second electrode 13 includes a second current collector 131 and a second active material layer 132. The second active material layer 132 is disposed on the side of the second current collector 131 facing the solid electrolyte layer 12. The electrode assembly 1 also includes a second mixing layer 15, which is disposed between the second active material layer 132 and the solid electrolyte layer 12. The second mixing layer 15 includes a third portion 151 made of the same material as the second active material layer 132 and a fourth portion 152 made of the same material as the solid electrolyte layer 12. The third portion 151 is connected to the second active material layer 132, and the fourth portion 152 is connected to the solid electrolyte layer 12. The third portion 151 and the fourth portion 152 are interlocked with each other.

[0154] The second active material layer 132 may be provided on only one side of the second current collector 131, and a solid electrolyte layer 12 may be provided on the side of the second active material layer 132 facing away from the second current collector 131; or the second active material layer 132 may be provided on both opposite sides of the second current collector 131, and a solid electrolyte layer 12 may be provided on the side of one second active material layer 132 facing away from the second current collector 131; a solid electrolyte layer 12 may also be provided on the side of the other second active material layer 132 facing away from the second current collector 131.

[0155] The second mixing layer 15 is disposed between the second active material layer 132 and the solid electrolyte layer 12 to connect the second active material layer 132 and the solid electrolyte layer 12. Alternatively, the second mixing layer 15, the second active material layer 132, and the solid electrolyte layer 12 can be separately arranged and connected, wherein the third part 151 and the fourth part 152 are interlocked to form the second mixing layer 15; or the second active material layer 132 and the third part 151 can be integrally formed, while the solid electrolyte layer 12 and the fourth part 152 can be separately arranged and connected, with the third part 151 and the fourth part 152 interlocked to form the second mixing layer 15; or the second active material layer 132 and the third part 151 can be integrally formed, while the solid electrolyte layer 12 and the fourth part 152 can be integrally formed, with the third part 151 and the fourth part 152 interlocked to form the second mixing layer 15; or the second active material layer 132 and the third part 151 can be integrally formed, while the solid electrolyte layer 12 and the fourth part 152 can be integrally formed, with the third part 151 and the fourth part 152 interlocked to form the second mixing layer 15.

[0156] The second active material layer 132 and the third part 151 are made of the same material, and the solid electrolyte layer 12 and the fourth part 152 are made of the same material.

[0157] The interlocking of the third part 151 and the fourth part 152 means that, along the thickness direction of the second mixing layer 15, at least a portion of the third part 151 is embedded in the fourth part 152, and at least a portion of the fourth part 152 is embedded in the third part 151, to form an interlocking structure. For example, the third part 151 has a groove structure on the side facing the solid electrolyte layer 12, and at least a portion of the fourth part 152 is embedded in the groove structure, so that the surface of the groove structure of the third part 151 is in contact with the surface of the portion of the fourth part 152 embedded in the groove structure; or, for example, the third part 151 has a hole structure on the side facing the solid electrolyte layer 12, and at least a portion of the fourth part 152 is embedded in the hole structure, so that the surface of the hole structure of the third part 151 is in contact with the surface of the portion of the fourth part 152 embedded in the hole structure.

[0158] By setting the second active material layer 132 and the third part 151 to be made of the same material and connecting them, the second active material layer 132 can transport ions through the outer surface of the third part 151. By setting the solid electrolyte layer 12 and the fourth part 152 to be made of the same material and connecting them, the solid electrolyte layer 12 can transport ions through the outer surface of the fourth part 152. By setting the third part 151 and the fourth part 152 to be interlocked, the outer surfaces of the third part 151 and the fourth part 152 are in contact, so as to form more ion channels between the outer surfaces of the third part 151 and the fourth part 152. This allows more ions to be inserted or extracted between the solid electrolyte layer 12 and the second active material layer 132, improving the charge and discharge performance of the electrode assembly 1, thereby improving the charge and discharge capability of the battery cell 10. The first mixing layer 14 can increase the ion channels between the first active material layer 112 and the solid electrolyte layer 12, and the second mixing layer 15 can increase the ion channels between the second active material layer 132 and the solid electrolyte layer 12, thereby enhancing the ion exchange capacity between the first electrode 11 and the second electrode 13 and the solid electrolyte layer 12, and thus improving the charge and discharge capacity of the battery cell 10.

[0159] In some embodiments, the thickness of the second hybrid layer 15 is 0.5 μm-10 μm.

[0160] The second active material layer 132, the second mixing layer 15, and the solid electrolyte layer 12 are stacked along the thickness direction of the solid electrolyte layer 12. The thickness of the second mixing layer 15 is the dimension of the second mixing layer 15 in the thickness direction of the solid electrolyte layer 12. The thickness of the second mixing layer 15 can be any one of 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm, 1μm, 15μm, 2μm, 2.5μm, 3μm, 3.5μm, 4μm, 4.5μm, 5μm, 5.5μm, 6μm, 6.5μm, 7μm, 7.5μm, 8μm, 8.5μm, 9μm, 9.5μm, and 1μm, or a range between any two.

[0161] The thickness of the first mixing layer 14 and the thickness of the second mixing layer 15 may be equal or unequal.

[0162] When the thickness of the second mixing layer 15 is greater than or equal to 0.5 μm, the second mixing layer 15 can provide more ion channels to the second active material layer 132 and the solid electrolyte layer 12, which is beneficial to improving the charge and discharge capacity of the battery cell 10. When the thickness of the second mixing layer 15 is less than or equal to 10 μm, the space occupied by the second mixing layer 15 in the electrode assembly 1 can be reduced, which is beneficial to reducing the impact of the second mixing layer 15 on the energy density of the electrode assembly 1. Therefore, when the thickness of the second mixing layer 15 is 0.5 μm-10 μm, it is possible to balance increasing the ion channels between the second active material layer 132 and the solid electrolyte layer 12 and reducing the impact of the second mixing layer 15 on the energy density of the electrode assembly 1.

[0163] In some embodiments, the third portion 151 is connected to the solid electrolyte layer 12.

[0164] The third part 151 may abut against the solid electrolyte layer 12, thereby connecting the third part 151 to the solid electrolyte layer 12; or the third part 151 may be bonded to the solid electrolyte layer 12, thereby connecting the third part 151 to the solid electrolyte layer 12. The fourth part 152 may be directly connected to the second active material layer 132; or the fourth part 152 may be indirectly connected to the second active material layer 132, for example, the fourth part 152 may be connected to the second active material layer 132 through the third part 151.

[0165] In this embodiment, the third part 151 connects the solid electrolyte layer 12 and the second active material layer 132. The third part 151 can provide a stable ion channel to the second active material layer 132 and the solid electrolyte layer 12, making the charge and discharge capability of the battery cell 10 more stable.

[0166] In some embodiments, the fourth portion 152 is connected to the second active material layer 132.

[0167] The fourth part 152 may abut against the second active material layer 132, so that the fourth part 152 and the second active material layer 132 are connected; or the fourth part 152 may be bonded to the second active material layer 132, so that the fourth part 152 and the second active material layer 132 are connected.

[0168] The third part 151 can be directly connected to the solid electrolyte layer 12; or the third part 151 can be indirectly connected to the solid electrolyte layer 12, for example, the third part 151 can be connected to the second active material layer 132 through the fourth part 152.

[0169] In this embodiment, the fourth part 152 connects the second active material layer 132 and the solid electrolyte layer 12. The fourth part 152 can provide a stable ion channel to the solid electrolyte layer 12 and the second active material layer 132, making the charge and discharge capability of the battery cell 10 more stable.

[0170] In some embodiments, the third portion 151 is connected to the solid electrolyte layer 12; the fourth portion 152 is connected to the second active material layer 132.

[0171] In this embodiment, both the third part 151 and the fourth part 152 are connected to the solid electrolyte layer 12 and the second active material layer 132. Both the third part 151 and the fourth part 152 can form a stable ion channel between the solid electrolyte layer 12 and the second active material layer 132. Furthermore, the third part 151 and the fourth part 152 are interlocked, and the area where the third part 151 and the fourth part 152 are in contact can also form an ion channel. This facilitates the insertion or extraction of ions between the solid electrolyte layer 12 and the second active material layer 132, thereby improving the charge and discharge capability of the battery cell 10.

[0172] In some embodiments, please continue to refer to Figures 3 and 11. Along the thickness direction of the solid electrolyte layer 12, the fourth portion 152 has a third surface 1521 and a fourth surface 1522 disposed opposite to each other; the fourth portion 152 is provided with a second through hole 1523, the two ends of the second through hole 1523 extending to the third surface 1521 and the fourth surface 1522 respectively; the third portion 151 includes a second fitting portion 1511, at least a portion of the second fitting portion 1511 being fitted into the second through hole 1523.

[0173] Both the third surface 1521 and the fourth surface 1522 can be planar or curved. The extension of both ends of the second through hole 1523 to the third surface 1521 and the fourth surface 1522 means that the second through hole 1523 penetrates the fourth part 152.

[0174] The second through hole 1523 can be one or more. In an embodiment where there is one second through hole 1523, the entire second fitting part 1511 can be fitted into the second through hole 1523; or only a portion of the second fitting part 1511 can be fitted into the second through hole 1523. In an embodiment where there are multiple second through holes 1523, only a portion of the multiple second through holes 1523 can have the second fitting part 1511 fitted into them; or each second through hole 1523 can have the second fitting part 1511 fitted into it.

[0175] The second fitting portion 1511 may be entirely contained within the second through hole 1523, or only a portion of the second fitting portion 1511 may be contained within the second through hole 1523.

[0176] In this embodiment, on the one hand, by providing a second through hole 1523 in the fourth part 152, the mutual fitting of the fourth part 152 and the third part 151 is made more convenient, reducing the processing cost of the second hybrid layer 15; on the other hand, by providing a second through hole 1523 in the fourth part 152 and embedding at least a portion of the second fitting part 1511 in the second through hole 1523, the amount of the third part 151 of the second active material layer 132 can be increased, thereby improving the energy density of the battery cell 10.

[0177] In some embodiments, the second fitting portion 1511 is entirely fitted into the second through hole 1523.

[0178] In an embodiment where there is one second through hole 1523, the second fitting portion 1511 may be entirely fitted into one second through hole 1523. In an embodiment where there are multiple second through holes 1523, the second fitting portion 1511 may be entirely fitted into only a portion of the multiple second through holes 1523; or the second fitting portion 1511 may be entirely fitted into each of the multiple second through holes 1523.

[0179] In this embodiment, the second through hole 1523 restricts the setting position of the third part 151, making the setting of the third part 151 more stable.

[0180] In some embodiments, please refer to Figures 8 and 12, where Figure 12 is a DD cross-sectional view of Figure 8. There are multiple second through holes 1523, which are spaced apart. There are multiple second fitting portions 1511, each corresponding to a second through hole 1523.

[0181] As an example, as shown in Figure 12, the second through holes 1523 are arranged in multiple rows and columns, and each second through hole 1523 is embedded with a second fitting part 1511.

[0182] In this embodiment, by providing a plurality of second through holes 1523 and embedding a second fitting part 1511 in each second through hole 1523, the ion channels between the second active material layer 132 and the solid electrolyte layer 12 can be increased, thereby enabling more ions to be inserted or extracted between the solid electrolyte layer 12 and the second active material layer 132, improving the charge and discharge performance of the electrode assembly 1, and thus improving the charge and discharge capability of the battery cell 10.

[0183] In some embodiments, please continue to refer to Figure 12. Within the cross-section of the same second mixing layer 15, the cross-sectional area of ​​the third portion 151 is S3, the cross-sectional area of ​​the fourth portion 152 is S4, 0.05≤S3 / (S3+S4)≤0.95, and the cross-section of the second mixing layer 15 is perpendicular to the thickness direction of the solid electrolyte layer 12.

[0184] The cross-sectional area of ​​the third part 151 refers to the total area of ​​the third part 151 within the cross-section of the second hybrid layer 15. For example, if the third part 151 includes only one second fitting portion 1511, the cross-sectional area of ​​the third part 151 is the area of ​​the second fitting portion 1511 within the cross-section of the second hybrid layer 15; or if the third part 151 includes multiple second fitting portions 1511, the cross-sectional area of ​​the third part 151 is the sum of the areas of the multiple second fitting portions 1511 within the cross-section of the second hybrid layer 15. The cross-sectional area of ​​the fourth part 152 refers to the area obtained by subtracting the cross-sectional area of ​​the third part 151 from the total cross-sectional area of ​​the second hybrid layer 15.

[0185] For example, the third part 151 has a plurality of second fitting portions 1511, and the sum of the cross-sectional areas of the plurality of second fitting portions 1511 is the cross-sectional area of ​​the third part 151.

[0186] The cross-sectional area of ​​the third part 151 can be the same as or different from the cross-sectional area of ​​the first part 141.

[0187] The value of S3 / (S3+S4) can be any one of the following values: 0.05, 01, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, or any value between two of them.

[0188] In this embodiment, when S3 / (S3+S4)≥0.05, the second mixed layer 15 can have a sufficient third portion 151, thereby increasing the material used in the second active material layer 132 in the electrode assembly 1 and improving the energy density of the electrode assembly 1; when S3 / (S3+S4)≤0.95, the second mixed layer 15 can have a sufficient fourth portion 152, thereby enhancing the ion-conducting ability of the second mixed layer 15; therefore, when 0.05≤S3 / (S3+S4)≤0.95, the energy density of the electrode assembly 1 and the ion-conducting ability of the second mixed layer 15 can be balanced, enhancing the performance of the second mixed layer 15.

[0189] In some embodiments, 0.2 ≤ S3 / (S3+S4) ≤ 0.6.

[0190] The value of S3 / (S3+S4) can be any one of the following values ​​or any value between two of them: 0.2, 0.22, 0.24, 0.25, 0.26, 0.28, 0.3, 0.32, 0.34, 0.35, 0.36, 0.38, 0.4, 0.42, 0.44, 0.45, 0.46, 0.48, 0.5, 0.52, 0.54, 0.55, 0.56, 0.58, and 0.6.

[0191] In this embodiment, when S3 / (S3+S4)≥0.2, the second mixed layer 15 can have more third portions 151, thereby further increasing the use of material in the second active material layer 132 in the electrode assembly 1 and improving the energy density of the electrode assembly 1; when S3 / (S3+S4)≤0.6, the second mixed layer 15 can have more fourth portions 152, thereby further enhancing the ion-conducting ability of the second mixed layer 15; therefore, when 0.05≤S3 / (S3+S4)≤0.95, the energy density of the electrode assembly 1 and the ion-conducting ability of the second mixed layer 15 can be further balanced, enhancing the performance of the second mixed layer 15.

[0192] In some embodiments, the third portion 151 is integrally formed with the second active material layer 132. In this embodiment, on the one hand, the processing of the third portion 151 and the second active material layer 132 is more convenient; on the other hand, the connection between the third portion 151 and the second active material layer 132 is tighter, which is beneficial to the electron transport between the third portion 151 and the second active material layer 132.

[0193] In some embodiments, the fourth portion 152 and the solid electrolyte layer 12 are integrally formed. In this embodiment, on the one hand, the processing of the third portion 151 and the solid electrolyte layer 12 is more convenient; on the other hand, the connection between the fourth portion 152 and the solid electrolyte layer 12 is more stable, which is beneficial to the ion conduction between the solid electrolyte layer 12 and the second active material layer 132.

[0194] In some embodiments, the third portion 151 is integrally formed with the second active material layer 132, and the fourth portion 152 is integrally formed with the solid electrolyte layer 12. In this embodiment, on the one hand, the electrode assembly 1 is easier to process; on the other hand, it can improve the conductivity of electrons between the second mixed layer 15 and the second active material layer 132, improve the conductivity of ions between the second mixed layer 15 and the solid electrolyte layer 12, and increase the ion channels between the solid electrolyte layer 12 and the second active material layer 132, thereby improving the charge and discharge capacity of the battery cell 10.

[0195] In some embodiments, the thickness of the solid electrolyte layer 12 is greater than or equal to the thickness of the second hybrid layer 15.

[0196] The thickness of the solid electrolyte layer 12 can be equal to the thickness of the second mixing layer 15, or the thickness of the solid electrolyte layer 12 can be greater than the thickness of the second mixing layer 15. The thickness of the solid electrolyte layer 12 also needs to be greater than or equal to the thickness of the first mixing layer 14.

[0197] For example, the thickness of the first mixing layer 14 is 9 μm, and the thickness of the second mixing layer 15 is 10 μm. The thickness of the solid electrolyte layer 12 can be 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, or 40 μm. μ m, 45μm, 50μm, 55μm, 60μm, etc.

[0198] In this embodiment, the solid electrolyte layer 12 has a relatively thick thickness, which improves the structural strength of the electrode assembly 1, thereby reducing the risk of the solid electrolyte layer 12 being broken down due to lithium plating. The thickness of the solid electrolyte layer 12 is greater than or equal to either the first mixed layer 14 or the second mixed layer 15, further reducing the risk of the solid electrolyte layer 12 being broken down due to lithium plating.

[0199] This application provides a battery device 100, which includes a battery cell 10 provided in any of the above embodiments.

[0200] This application provides an electrical device, including a battery cell 10 or a battery device 100 provided in any of the above embodiments, wherein the battery cell 10 is used to provide electrical energy to the electrical device.

[0201] Please refer to Figures 3, 4, and 7-12. This application provides a battery cell 10, which includes a housing 2 and an electrode assembly 1. The electrode assembly 1 is housed within the housing 2 and includes a first electrode 11, a solid electrolyte layer 12, and a second electrode 13 stacked together. The first electrode 11 and the second electrode 13 have opposite polarities. The solid electrolyte layer 12 is disposed between the first electrode 11 and the second electrode 13. The first electrode 11 includes a first current collector 111 and a first active material layer 112, with the first active material layer 112 disposed on the side of the first current collector 111 facing the solid electrolyte layer 12. The second electrode 13 includes a second current collector 131 and a second active material layer 132, with the second active material layer 132 disposed on the side of the second current collector 131 facing the solid electrolyte layer 12. The electrode assembly 1 further includes a first mixing layer 14 and a second mixing layer 15. The first mixing layer 14 is disposed between the first active material layer 112 and the solid electrolyte layer 12. The first mixing layer 14 includes a first part 141 made of the same material as the first active material layer 112 and a second part 142 made of the same material as the solid electrolyte layer 12. The first part 141 is connected to the first active material layer 112, and the second part 142 is connected to the solid electrolyte layer 12. The first part 141 and the second part 142 are interlocked with each other. The second mixing layer 15 is disposed between the second active material layer 132 and the solid electrolyte layer 12. The second mixing layer 15 includes a third part 151 made of the same material as the second active material layer 132 and a fourth part 152 made of the same material as the solid electrolyte layer 12. The third part 151 is connected to the second active material layer 132, and the fourth part 152 is connected to the solid electrolyte layer 12. The third part 151 and the fourth part 152 are interlocked with each other.

[0202] By setting the first active material layer 112 to be of the same material as the first portion 141, and connecting the first active material layer 112 and the first portion 141, ions can be transported through the outer surface of the first portion 141 by the first active material layer 112. By setting the solid electrolyte layer 12 to be of the same material as the second portion 142, and connecting the solid electrolyte layer 12 and the second portion 142, ions can be transported through the outer surface of the second portion 142 by the solid electrolyte layer 12. By setting the first portion 141 and the second portion 142 to be interlocked, the outer surfaces of the first portion 141 and the second portion 142 are in contact, thereby forming more ion channels between the outer surfaces of the first portion 141 and the second portion 142. By setting the second active material layer 132 to be of the same material as the third portion 151, and connecting the second active material layer 132 and the third portion 151, ions can be transported through the outer surface of the third portion 151 by the second active material layer 132. By making the solid electrolyte layer 12 and the fourth part 152 the same material, and connecting the solid electrolyte layer 12 and the fourth part 152, the solid electrolyte layer 12 can transport ions through the outer surface of the fourth part 152. By making the third part 151 and the fourth part 152 interlocked, the outer surfaces of the third part 151 and the fourth part 152 are in contact, thereby forming more ion channels between the outer surfaces of the third part 151 and the fourth part 152. In this way, more ions can be inserted or extracted between the first electrode 11 and the solid electrolyte layer 12, as well as between the second electrode 13 and the solid electrolyte layer 12, improving the charge and discharge performance of the electrode assembly 1, thereby increasing the charge and discharge capability of the battery cell 10.

[0203] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A single battery cell, comprising: shell; An electrode assembly is housed within the housing. The electrode assembly includes a first electrode, a solid electrolyte layer, and a second electrode stacked together. The first electrode and the second electrode have opposite polarities. At least a portion of the solid electrolyte layer is disposed between the first electrode and the second electrode. The first electrode includes a first current collector and a first active material layer. The first active material layer is disposed on the side of the first current collector facing the solid electrolyte layer. The electrode assembly further includes a first mixing layer disposed between the first active material layer and the solid electrolyte layer. The first mixing layer includes a first part made of the same material as the first active material layer and a second part made of the same material as the solid electrolyte layer. The first part is connected to the first active material layer, and the second part is connected to the solid electrolyte layer. The first part and the second part are interlocked with each other.

2. The battery cell as described in claim 1, wherein, The thickness of the first hybrid layer is 0.5μm-10μm.

3. The battery cell as described in claim 1 or 2, wherein, The first portion is connected to the solid electrolyte layer; and / or, the second portion is connected to the first active material layer.

4. The battery cell according to any one of claims 1-3, wherein, Along the thickness direction of the solid electrolyte layer, the second portion has a first surface and a second surface disposed opposite to each other; The second part is provided with a first through hole, the two ends of the first through hole extending to the first surface and the second surface respectively, and the first part includes a first fitting part, at least a portion of the first fitting part being fitted into the first through hole.

5. The battery cell as described in claim 4, wherein, The first fitting part is completely embedded in the first through hole.

6. The battery cell as described in claim 4 or 5, wherein, There are multiple first through holes, and the multiple first through holes are spaced apart; There are multiple first fitting parts, and each first fitting part corresponds to a first through hole.

7. The battery cell according to any one of claims 1-6, wherein, Within the same first hybrid layer, the cross-sectional area of ​​the first part is S1, the cross-sectional area of ​​the second part is S2, 0.05≤S1 / (S1+S2)≤0.95, and the cross-section of the first hybrid layer is perpendicular to the thickness direction of the solid electrolyte layer.

8. The battery cell as described in claim 7, wherein, 0.2≤S1 / (S1+S2)≤0.

6.

9. The battery cell according to any one of claims 1-8, wherein, The first portion is integrally formed with the first active material layer; and / or, the second portion is integrally formed with the solid electrolyte layer.

10. The battery cell according to any one of claims 1-9, wherein, The thickness of the solid electrolyte layer is greater than or equal to the thickness of the first hybrid layer.

11. The battery cell according to any one of claims 1-10, wherein, The first active material layer is provided on both sides of the first current collector. The first active material layer on one side of the first current collector is provided with a first mixing layer between it and one of the solid electrolyte layers. The first active material layer on the other side of the first current collector is provided with a first mixing layer between it and another solid electrolyte layer.

12. The battery cell according to any one of claims 1-11, wherein, The second electrode includes a second current collector and a second active material layer, wherein the second active material layer is disposed on the side of the second current collector facing the solid electrolyte layer; The electrode assembly further includes a second mixing layer disposed between the second active material layer and the solid electrolyte layer. The second mixing layer includes a third part made of the same material as the second active material layer and a fourth part made of the same material as the solid electrolyte layer. The third part is connected to the second active material layer, and the fourth part is connected to the solid electrolyte layer. The third part and the fourth part are interlocked with each other.

13. The battery cell as described in claim 12, wherein, The thickness of the second hybrid layer is 0.5μm-10μm.

14. The battery cell as described in claim 12 or 13, wherein, The third part is connected to the solid electrolyte layer; and / or, the fourth part is connected to the second active material layer.

15. The battery cell according to any one of claims 12-14, wherein, Along the thickness direction of the solid electrolyte layer, the fourth portion has a third surface and a fourth surface disposed opposite to each other; The fourth part is provided with a second through hole, the two ends of which extend to the third surface and the fourth surface respectively. The third part includes a second fitting portion, at least part of which is fitted into the second through hole.

16. The battery cell as described in claim 15, wherein, The second fitting part is completely embedded in the second through hole.

17. The battery cell as described in claim 15 or 16, wherein, There are multiple second through holes, which are spaced apart. There are multiple second fitting parts, and each second fitting part corresponds to a second through hole.

18. The battery cell according to any one of claims 12-17, wherein, Within the same cross-section of the second hybrid layer, the cross-sectional area of ​​the third part is S3, the cross-sectional area of ​​the fourth part is S4, 0.05≤S3 / (S3+S4)≤0.95, and the cross-section of the second hybrid layer is perpendicular to the thickness direction of the solid electrolyte layer.

19. The battery cell as claimed in claim 18, wherein, 0.2≤S3 / (S3+S4)≤0.

6.

20. The battery cell according to any one of claims 12-19, wherein, The third part and the second active material layer are integrally formed; and / or, the fourth part and the solid electrolyte layer are integrally formed.

21. The battery cell according to any one of claims 12-20, wherein, The thickness of the solid electrolyte layer is greater than or equal to the thickness of the second hybrid layer.

22. A battery device comprising a battery cell as described in any one of claims 1-21.

23. An electrical device comprising a battery cell as described in any one of claims 1-21 or a battery device as described in claim 22, wherein the battery cell is used to provide electrical energy to the electrical device.

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