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 casing and an electrode assembly accommodated in the casing. The electrode assembly comprises a plurality of first electrode sheets and a plurality of second electrode sheets. The first electrode sheets and the second electrode sheets are alternately stacked in a first direction, the polarities of the first electrode sheets and the second electrode sheets being opposite. Each first electrode sheet comprises a first electrode sheet body and a first tab, the first tab protruding from the edge of the first electrode sheet body, and at least one side of the first electrode sheet body in the first direction being provided with a recess. Each second electrode sheet comprises a second electrode sheet body and a second tab, at least part of the second electrode sheet body being accommodated in the recess, and the orthographic projection of the second electrode sheet body in the first direction being located within the orthographic projection of the recess in the first direction. The present application can improve the reliability of the battery cell.

Description

Battery cell, battery device and electric device

[0001] Cross Reference to Related Applications

[0002] This application claims priority to Chinese Patent Application No. 202411127187.1, filed on August 19, 2024, entitled “Battery cell, battery device and electric device”, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the technical field of battery, in particular to a battery cell, a battery device and an electric device. BACKGROUND

[0004] Battery cells are widely used in electronic devices, such as mobile phones, notebook computers, electric vehicles, electric cars, electric planes, electric ships, electric toy cars, electric toy ships, electric toy planes and electric tools, etc. Battery cells can include cadmium-nickel battery cells, hydrogen-nickel battery cells, lithium-ion battery cells and secondary alkaline zinc-manganese battery cells, etc.

[0005] In the development of battery technology, how to improve the reliability of battery cells has always been a research direction in battery technology. SUMMARY

[0006] In view of the above problems, the present application provides a battery cell, a battery device and an electric device, which can improve the reliability of the battery cell.

[0007] In a first aspect, the present application provides a battery cell, the battery cell comprising a shell and an electrode assembly contained in the shell. The electrode assembly comprises a plurality of first pole pieces and a plurality of second pole pieces. The first pole pieces and the second pole pieces are alternately stacked along a first direction, and the first pole pieces and the second pole pieces have opposite polarities. The first pole piece comprises a first pole piece main body and a first tab, the first tab protruding from an edge of the first pole piece main body, and the first pole piece main body is provided with a recess on at least one side thereof along the first direction. The second pole piece comprises a second pole piece main body and a second tab, at least part of the second pole piece main body is contained in the recess, and the orthographic projection of the second pole piece main body along the first direction is located within the orthographic projection of the recess along the first direction.

[0008] In the above scheme, by providing a recess and containing the second pole piece main body in the recess, the distance between the regions of two adjacent first pole pieces beyond the second pole piece is shortened, thereby reducing the risk of fracture of the pole pieces caused by excessive bending radius of the regions of the adjacent first pole pieces beyond the second pole piece in the preparation process, and improving the reliability of the battery cell.

[0009] In some embodiments, the first tab body includes a first current collector, a first active material layer, and a support structure. The first tab lug is connected to the first current collector, the first active material layer is disposed on a surface of the first current collector, the support structure is connected to the first active material layer and disposed along a circumferential direction of the first tab body, at least part of the support structure protrudes from the first active material layer away from the surface of the first current collector. The support structure and the first active material layer enclose a recess.

[0010] In the above scheme, by providing the support structure, the distance between the overhang regions of two adjacent first tabs is shortened, thereby reducing the risk of breakage of the overhang region of the first tab during the preparation process, and improving the reliability of the battery cell.

[0011] In some embodiments, the support structure includes a first part and a second part, the second part protrudes from the first part along the first direction, the second part forms at least part of the side wall of the recess, and the edge of the second tab body is located within the projection of the first part along the first direction.

[0012] In the above scheme, by the above arrangement, it is beneficial to increase the overall area of the second tab, reduce the risk of ion precipitation of the battery cell, and reduce the risk of short circuit caused by burrs on the edge of the second tab and the lap joint of the first tab.

[0013] In some embodiments, the first active material layer includes a first active material body and a thinned part, the thinned part is disposed along the circumferential direction of the first active material body, and at least part of the first part is located on the side of the thinned part away from the first current collector.

[0014] In the above scheme, by the above arrangement, it is beneficial to increase the connection area of the support structure and the first tab body, thereby reducing the possibility of separation of the support structure and the first tab body, and beneficial to disperse the interaction force when the support structures abut each other to the first tab body, thereby reducing the risk that the abutment of the support structures causes the support structures to break the first tab body.

[0015] In some embodiments, the side surface of the first part away from the first current collector is flush with the side surface of the first active material body away from the first current collector, so as to reduce the possibility that the edge thickness of the first tab and the second tab after lamination is greater than the thickness of the central region of the first tab and the second tab, improve the thickness uniformity of the electrode assembly, and improve the reliability of the battery cell.

[0016] In some embodiments, the number of support structures includes two, and the two support structures are separately arranged on the two sides of the first current collector along the first direction.

[0017] In the above scheme, by arranging the support structures on both sides of the first current collector, when the overhang regions of the two first electrode tabs are relatively close, the support structures on the two first electrode tabs interact to disperse the force to the two electrode tabs, further reducing the possibility of breakage of the overhang regions during preparation, and improving the reliability of the battery cell.

[0018] In some embodiments, the size of the second part in the first direction is equal to half of the size of the second electrode tab in the first direction, so that after the support structures on the two first electrode tabs are buckled, the second electrode tab is accommodated in the recess of the two first electrode tabs, thereby reducing the possibility of misalignment of the first electrode tab and the second electrode tab.

[0019] In some embodiments, the support structure is located on one side of the first current collector in the first direction.

[0020] In the above scheme, by arranging the support structures on one side of the first current collector, the preparation process of the first electrode tab is facilitated, the production efficiency of the first electrode tab is improved, and the manufacturing cost of the battery cell is reduced.

[0021] In some embodiments, the size of the second part in the first direction is equal to the size of the second electrode tab in the first direction, which facilitates reducing the redundant arrangement of the support structure while enabling the support structure on the first electrode tab to support the overhang region of the adjacent first electrode tab body, reducing the possibility of bending of the first electrode tab during preparation, and improving the reliability of the battery cell.

[0022] In some embodiments, the second tab protrudes from the edge of the second electrode tab body, the second part is provided with an opening, and the second tab protrudes from the recess through the opening.

[0023] In the above scheme, the second tab is arranged to protrude from the peripheral side of the second electrode tab body, the second electrode tab body is accommodated in the recess, and the opening provided in the second part forms a gap in the side wall of the recess. The second tab can protrude into the recess through the opening, thereby reducing the possibility of interference between the side wall of the recess and the second tab.

[0024] In some embodiments, the first electrode tab is a positive electrode tab, and the second electrode tab is a negative electrode tab. In combination with the above technical scheme, the positive projection of the edge of the second electrode tab body in the first direction is arranged in the positive projection of the first part in the first direction, which facilitates reducing the risk of ion precipitation of the battery cell and the risk of short circuit of the battery cell caused by the burr of the edge of the second electrode tab body and the lapping of the first electrode tab.

[0025] In some embodiments, the surface of the second electrode tab is provided with a solid-state electrolyte layer, and the solid-state electrolyte layer covers the second electrode tab body and at least part of the second tab.

[0026] In the above scheme, by covering the second pole piece body and at least part of the second pole lug with the solid electrolyte layer, the separation effect of the solid electrolyte layer on the oppositely arranged first active material layer and the second active material layer is improved, the possibility of short circuit of the oppositely arranged first active material layer and the second active material layer is reduced, and the risk of battery monomer short circuit is reduced, thereby improving the reliability of the battery monomer.

[0027] In a second aspect, the embodiments of the present application provide a power utilization device, comprising the battery device in any of the foregoing embodiments, and the battery device is configured to provide electric energy.

[0028] In a third aspect, the embodiments of the present application provide a power utilization device, comprising the battery device in any of the foregoing embodiments, and the battery device is configured to provide electric energy.

[0029] The above description is only a summary of the technical solutions of the present application. In order to more clearly understand the technical means of the present application, the following specific embodiments of the present application can be implemented according to the content of the description, and in order to make the above and other purposes, characteristics and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0031] FIG. 1 is a structural schematic diagram of a vehicle according to an embodiment of the present application;

[0032] FIG. 2 is an exploded structural schematic diagram of a battery according to an embodiment of the present application;

[0033] FIG. 3 is a structural schematic diagram of a battery module according to an embodiment of the present application;

[0034] FIG. 4 is a structural schematic diagram of a battery monomer according to an embodiment of the present application;

[0035] FIG. 5 is a sectional structural schematic diagram of a battery monomer according to an embodiment of the present application;

[0036] FIG. 6 is an exploded sectional schematic diagram of an electrode assembly in a battery monomer according to an embodiment of the present application;

[0037] FIG. 7 is an enlarged structural schematic diagram of P in FIG. 6;

[0038] FIG. 8 is a structural schematic diagram of a first pole piece in a battery monomer according to an embodiment of the present application;

[0039] Fig. 9 is a schematic diagram of an enlarged structure of P in Fig. 6;

[0040] Fig. 10 is a schematic diagram of an exploded view of an electrode assembly in a battery cell according to an embodiment of the present application;

[0041] Fig. 11 is a schematic diagram of an enlarged structure of Q in Fig. 10;

[0042] Fig. 12 is a schematic diagram of a structure of a second tab in a battery cell according to an embodiment of the present application.

[0043] Label Description 1000, vehicle; 100, battery device; 200, controller; 300, motor; 400, case; 410, first case portion; 420, second case portion; 430, accommodation portion; 500, battery module; 110, battery cell; 101, housing; 102, electrode assembly; 10, first tab; 11, first tab body; 111, first current collector; 112, first active material layer; 112a, first active material body; 112b, thinning portion; 113, support structure; 113a, first sub-portion; 113b, second sub-portion; 12, first tab; 13, recess; 20, second tab; 21, second tab body; 211, second current collector; 212, second active material layer; 22, second tab; 23, solid-state electrolyte layer; K1, opening; Z, first direction. DETAILED DESCRIPTION

[0044] The embodiments of the technical solutions of the present application will be described in detail below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0045] 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 belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion.

[0046] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified.

[0047] Reference to“an embodiment” herein means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase“in an embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. It is expressly understood that any of the embodiments described herein can be incorporated into any other embodiment in a manner known to those of ordinary skill in the art.

[0048] In the description of the embodiments of the application, the term“and / or” only means an association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can mean that A exists alone, A and B exist together, and B exists alone. In addition, the character“ / ” herein generally means that the front and rear associated objects are in an“or” relationship.

[0049] In the description of the embodiments of the application, the term“a plurality of” means more than two (including two), and similarly, “a plurality of groups” means more than two groups (including two groups), and “a plurality of pieces” means more than two pieces (including two pieces).

[0050] In the description of the embodiments of the application, the technical terms“center”,“longitudinal”,“transverse”,“length”,“width”,“thickness”,“upper”,“lower”,“front”,“rear”,“left”,“right”,“vertical”,“horizontal”,“top”,“bottom”,“inner”,“outer”,“clockwise”,“counterclockwise”,“axial”,“radial”,“circumferential” and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the embodiments of the application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the application.

[0051] In the description of the embodiments of the application, unless otherwise explicitly specified and limited, the technical terms“mounting”,“connection”,“connection”,“fixing” and the like should be understood broadly, for example, can be fixedly connected, or can be detachably connected, or can be integrated; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium; can be the internal communication of two elements or the interaction relationship of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the application can be understood according to the specific circumstances.

[0052] In the embodiments of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be activated by charging after discharging of the battery cell.

[0053] The battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead-acid battery, etc. The embodiments of the present application are not limited thereto.

[0054] The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator disposed between the negative electrode and the positive electrode. During charging and discharging of the battery cell, active ions (e.g., lithium ions) are intercalated and deintercalated between the positive electrode and the negative electrode. The separator, which is disposed between the positive electrode and the negative electrode, can prevent the positive electrode and the negative electrode from shorting while allowing the active ions to pass through.

[0055] In some embodiments, the positive electrode can be a positive electrode sheet, which can include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0056] As an example, the positive electrode current collector has two surfaces opposite in the thickness direction thereof, and the positive electrode active material is disposed on either one or both of the two opposite surfaces of the positive electrode current collector.

[0057] As an example, the positive electrode current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, a pure metal, an alloy, a surface-treated metal, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver, etc. can be used. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector 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 base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0058] As an example, the positive electrode active material can include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other conventional materials that can be used as battery positive electrode active materials can also be used. These positive electrode active materials can be used alone or in combination with two or more. Among them, examples of lithium-containing phosphates can include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP for short)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon. Examples of lithium transition metal oxides can include, but are not limited to, at least one of lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co1 / 3 Mn 1 / 3 O2(also can be referred to as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2(also can be referred to as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2(also can be referred to as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2(also can be referred to as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2(also can be referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.8 Co 0.15 Al 0.05 O2), and modified compounds thereof. The modified compounds refer to substances obtained by modification means such as doping or coating on the basis of the above-mentioned substances.

[0059] In some embodiments, the positive electrode can adopt a foam metal. The foam metal can be a foam nickel, a foam copper, a foam aluminum, a foam alloy, or a foam carbon, etc. When the foam metal is used as the positive electrode, the surface of the foam metal can not be provided with the positive electrode active material, or of course can be provided with the positive electrode active material. As an example, the positive electrode active material is filled or / and deposited in the foam metal.

[0060] In some embodiments, the negative electrode can be a negative electrode sheet, and the negative electrode sheet can include a negative electrode current collector.

[0061] As an example, the negative electrode current collector can adopt a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as the metal foil, a pure metal, an alloy, a surface-treated metal, including but not limited to stainless steel, copper, aluminum, nickel, nickel alloy, titanium, or silver, etc. can be adopted. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector 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 base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0062] As an example, the negative electrode sheet can include the negative electrode current collector and the negative electrode active material provided on at least one surface of the negative electrode current collector.

[0063] As an example, the negative electrode current collector has two surfaces opposite in the thickness direction thereof, and the negative electrode active material is provided on either one or both of the two surfaces of the negative electrode current collector.

[0064] As an example, the negative electrode active material can employ a negative electrode active material for a battery cell known in the art. As an example, the negative electrode active material can include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, a silicon-based material, a tin-based material, and lithium titanate, etc. The silicon-based material can be selected from at least one of elemental silicon, a silicon oxide compound, a silicon-carbon composite, a silicon-nitrogen composite, and a silicon alloy. The tin-based material can be selected from at least one of elemental tin, a tin oxide compound, and a tin alloy. However, the present application is not limited to these materials, and other conventional materials that can be used as a negative electrode active material for a battery cell can also be used. These negative electrode active materials can be used alone or in combination of two or more.

[0065] In some embodiments, the negative electrode can employ a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. When the foamed metal is used as a negative electrode sheet, the foamed metal surface can not be provided with a negative electrode active material, or can be provided with a negative electrode active material.

[0066] As an example, the negative electrode active material can be filled or / and deposited in the negative electrode current collector.

[0067] In some embodiments, the material of the positive electrode current collector can be aluminum, and the material of the negative electrode current collector can be copper.

[0068] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0069] In some embodiments, the separator is a solid-state electrolyte. The solid-state electrolyte is disposed between the positive electrode and the negative electrode, and functions to transport ions and separate the positive electrode and the negative electrode.

[0070] In some embodiments, the battery cell further includes an electrolyte that functions to conduct ions between the positive electrode and the negative electrode. The type of the electrolyte is not specifically limited in the present application, and can be selected as needed. The electrolyte can be solid.

[0071] The solid-state electrolyte includes a polymer solid-state electrolyte, an inorganic solid-state electrolyte, and a composite solid-state electrolyte.

[0072] As an example, the polymer of the polymer solid-state electrolyte can include polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, a single-ion polymer, a polyionic liquid, cellulose, etc.

[0073] As an example, the inorganic solid-state electrolyte can be one or more of an oxide solid-state electrolyte (crystalline perovskite, sodium superionic conductor, garnet, amorphous LiPON thin film), a sulfide solid-state electrolyte (crystalline lithium superionic conductor (lithium germanium phosphorous sulfide, argyrodite), amorphous sulfide), and a halide solid-state electrolyte, a nitride solid-state electrolyte, and a hydride solid-state electrolyte.

[0074] As an example, the composite solid-state electrolyte is formed by adding an inorganic solid-state electrolyte filler to a polymer solid-state electrolyte.

[0075] In some embodiments, the electrode assembly is a stack structure.

[0076] As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets can be provided, and the plurality of positive electrode sheets and the plurality of negative electrode sheets can be alternately stacked.

[0077] As an example, a plurality of positive electrode sheets can be provided, and a negative electrode sheet can be folded to form a plurality of folded segments that are stacked.

[0078] As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets can be provided, and the plurality of positive electrode sheets and the plurality of negative electrode sheets can be alternately stacked.

[0079] In some embodiments, the electrode assembly can have a cylindrical shape, a flat shape, or a multi-prism shape, etc.

[0080] In some embodiments, the electrode assembly can be provided with a tab, and the tab can guide current out of the electrode assembly. The tab can include a positive tab and a negative tab.

[0081] In some embodiments, the battery cell can include a housing. The housing can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film, etc. In some embodiments, the housing can be a sealed structure or a non-sealed structure. As an example, when the housing is a non-sealed structure, the housing serves to protect the electrode assembly, and a sealing bag is further included between the housing and the electrode assembly, and the sealing bag is used to package the electrode assembly and the electrolyte. Specifically, the sealing bag can be a bag-shaped insulating member or an aluminum-plastic film. When the housing is a sealed structure, the housing is used to package the electrode assembly and the electrolyte, etc.

[0082] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes, and the prismatic battery cell includes a square battery cell, a blade-shaped battery cell, a multi-prismatic battery cell, such as a hexagonal prismatic battery cell, etc., without specific limitation in the present application.

[0083] The battery apparatus mentioned in the embodiments of the present application can include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly can include a plurality of battery cells connected in series, in parallel, or in a mixed connection through a busbar component.

[0084] In some embodiments, the battery cell assembly is generally formed by arranging a plurality of battery cells.

[0085] As an example, the battery cell assembly can be a battery module formed by arranging and fixing a plurality of battery cells into a separate module. As an example, the battery module can be formed by bundling a plurality of battery cells with a cable tie.

[0086] In some embodiments, the battery apparatus can be a battery pack including a case and one or more battery cell assemblies housed in the case.

[0087] As an example, the battery cell assembly can be a battery module, which can be housed in the case by fixing the battery module in the case.

[0088] As an example, the battery cell assembly can also be housed in the case by directly fixing a plurality of battery cells in the case.

[0089] As an example, the case can include a first case and a second case. The first case and the second case are coupled so that an enclosed space is formed inside the case to accommodate the battery cell assembly. Here, enclosed means covered or closed, which can be sealed or unsealed. The first case can be a top cover or a bottom plate.

[0090] As an example, the case can include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame so that an enclosed space is formed inside the case to accommodate the battery cell assembly.

[0091] In some embodiments, the case can be part of the chassis structure of a vehicle. For example, part of the case can be at least part of the floor of the vehicle, or part of the case can be at least part of the cross beam and the longitudinal beam of the vehicle.

[0092] The technical solutions described in the embodiments of the present application are applicable to various electric devices using battery cells, such as mobile phones, portable devices, notebook computers, electric vehicles, electric toys, electric tools, vehicles, ships, and spacecraft, such as aircraft, rockets, space shuttles, and spacecraft.

[0093] The development of battery technology needs to consider various design factors, such as energy density, cycle life, discharge capacity, charge-discharge rate, and other performance parameters, and the reliability of the battery cell.

[0094] The battery cell includes an electrode assembly, which is a component where electrochemical reactions occur in the battery cell and is a core component in the battery cell. In the preparation process, the negative electrode sheet and the positive electrode sheet are usually aligned and stacked with each other. However, due to the limitations of the process capacity, there is a certain deviation between the negative electrode sheet and the positive electrode sheet in the direction perpendicular to the stacking direction, and the two cannot be aligned with each other, resulting in a part of the positive electrode sheet not corresponding to the negative electrode sheet, so that the active ions extracted from the positive electrode sheet cannot be effectively inserted into the negative electrode sheet, causing the problem of ion precipitation between the negative electrode sheet and the positive electrode sheet.

[0095] Therefore, when designing the electrode assembly, the negative electrode sheet is generally designed to be excessive to exceed the positive electrode sheet, and the excess part is called the overhang region. There is no positive electrode sheet as support between the overhang regions of the two adjacent negative electrode sheets, and in some preparation processes (such as isostatic pressing densification process), the overhang region of the negative electrode sheet is easy to bend or even break, causing the reliability of the battery cell to decrease.

[0096] Based on the above technical problems, the present application provides a technical solution, by setting a recess and accommodating the second electrode sheet body in the recess, the distance between the regions of the two adjacent first electrode sheets exceeding the second electrode sheet is shortened, thereby reducing the risk of electrode sheet fracture caused by the excessive bending radius of the regions of the two adjacent first electrode sheets exceeding the second electrode sheet in the preparation process, and improving the reliability of the battery cell.

[0097] The battery cell described in the embodiments of the present application is not only limited to the above-described electric device, but for the sake of brevity, the following embodiments are described with the electric vehicle as an example.

[0098] Please refer to FIG. 1, which is a structural schematic diagram of a vehicle according to an embodiment of the present application. The vehicle 1000 can be a fuel automobile, a gas automobile or a new energy automobile, and the new energy automobile can be a pure electric automobile, a hybrid automobile or a range extended automobile, etc. The vehicle 1000 can be provided with a battery device 100, for example, at the bottom, the front or the rear of the vehicle 1000. The battery device 100 can be used for power supply of the vehicle 1000, for example, as the operating power source of the vehicle 1000. The vehicle 1000 can further include a controller 200 and a motor 300, and the controller 200 can be used to control the power supply of the motor 300 by the battery. The battery can be used for starting and navigation of the vehicle 1000, and of course, the battery device 100 can also be used to drive the vehicle 1000 to run, instead of or partially instead of fuel or natural gas to provide driving for the vehicle 1000.

[0099] FIG. 2 is an exploded structural schematic diagram of a battery according to an embodiment of the present application. As shown in FIG. 2, the battery device 100 includes a box body 400 and a battery cell (not shown in the figure), and the battery cell is accommodated in the box body 400.

[0100] The box body 400 is used to accommodate the battery cell, and the box body 400 can be of various structures. In some embodiments, the box body 400 can include a first box body part 410 and a second box body part 420, the first box body part 410 and the second box body part 420 are mutually covered, and the first box body part 410 and the second box body part 420 jointly define an accommodation part 430 for accommodating the battery cell. The second box body part 420 can be a hollow structure with one end open, and the first box body part 410 is a plate-shaped structure, which is covered on the open side of the second box body part 420 to form the box body with the accommodation part 430; or the first box body part 410 and the second box body part 420 can both be a hollow structure with one side open, and the open side of the first box body part 410 is covered on the open side of the second box body part 420 to form the box body 400 with the accommodation part 430. Of course, the first box body part 410 and the second box body part 420 can be of various shapes, such as a cylinder, a cuboid, etc.

[0101] In the battery device 100, the battery cell can be multiple. The multiple battery cells can be connected in series, in parallel or in a mixed manner, and the mixed manner means that the multiple battery cells are connected in series and in parallel. The multiple battery cells can be directly connected in series, in parallel or in a mixed manner, and then the whole of the multiple battery cells is accommodated in the box body 400; or the multiple battery cells can be first connected in series, in parallel or in a mixed manner to form a battery module 500, and then the multiple battery modules 500 are connected in series, in parallel or in a mixed manner to form a whole, which is accommodated in the box body 400.

[0102] FIG. 3 is a structural schematic diagram of a battery module according to an embodiment of the present application.

[0103] In some embodiments, as shown in FIG. 3, the battery cell 110 is in plurality, and the plurality of battery cells 110 are connected in series or in parallel or in a mixed manner to form a battery module 500. The plurality of battery modules 500 are connected in series or in parallel or in a mixed manner to form an entirety and are accommodated in a box.

[0104] FIG. 4 is a structural schematic diagram of a battery cell according to an embodiment of the present application. FIG. 5 is a sectional structural schematic diagram of a battery cell according to an embodiment of the present application. FIG. 6 is an exploded sectional schematic diagram of an electrode assembly in a battery cell according to an embodiment of the present application. FIG. 7 is an enlarged structural schematic diagram of P in FIG. 6.

[0105] Referring to FIGS. 4-7, the present application provides a battery cell 110, which includes a housing 101 and an electrode assembly 102 accommodated in the housing 101. The electrode assembly 102 includes a plurality of first electrode sheets 10 and a plurality of second electrode sheets 20. The first electrode sheets 10 and the second electrode sheets 20 are alternately stacked along a first direction Z, and the first electrode sheets 10 and the second electrode sheets 20 are opposite in polarity. The first electrode sheet 10 includes a first electrode sheet body 11 and a first electrode tab 12 protruding from an edge of the first electrode sheet body 11, and the first electrode sheet body 11 is provided with a recess 13 on at least one side thereof along the first direction Z. The second electrode sheet 20 includes a second electrode sheet body 21 and a second electrode tab 22, at least a portion of the second electrode sheet body 21 is accommodated in the recess 13, and the second electrode sheet body 21 is located within the projection of the recess 13 along the first direction Z.

[0106] Optionally, one of the first electrode sheet 10 and the second electrode sheet 20 is a positive electrode sheet, and the other is a negative electrode sheet. For example, the first electrode sheet 10 is a positive electrode sheet, and the second electrode sheet 20 is a negative electrode sheet. Alternatively, the first electrode sheet 10 is a negative electrode sheet, and the second electrode sheet 20 is a positive electrode sheet.

[0107] Optionally, the electrode assembly can be a stacked sheet structure, for example, the plurality of first electrode sheets and the plurality of second electrode sheets can be alternately stacked in sequence to form the electrode assembly.

[0108] Optionally, the first electrode tab 12 and the second electrode tab 22 can be located on the same side of the electrode assembly 102, of course, they can also be located on different sides.

[0109] It can be understood that the first electrode sheet body 11 is provided with a recess 13 on at least one side thereof along the first direction Z, and a portion of the structure of the first electrode sheet body 11 protrudes to form a side wall of the recess 13. Optionally, the protruding portion can be an overhang region of the first electrode sheet body 11.

[0110] In some examples, the first tab body 11 is provided with a recess 13 on one side in the first direction Z. In other examples, the first tab body 11 is provided with a recess 13 on both sides in the first direction Z.

[0111] Exemplarily, the recesses 13 on both sides of the first tab body 11 in the first direction Z can have completely coinciding orthographic projections in the first direction Z. Of course, the recesses 13 on opposite sides of the first tab body 11 in the first direction Z can also be arranged in an overlapping manner.

[0112] Optionally, the recesses 13 on both sides of the first tab body 11 in the first direction Z can have the same depth,

[0113] Of course, the recesses 13 on both sides of the first tab body 11 in the first direction Z can also have different depths.

[0114] Optionally, the entire structure of the second tab body 21 in the first direction Z is accommodated in the recess 13, or a part of the structure of the second tab body 21 in the first direction Z is accommodated in the recess 13. In the second direction, the entire structure of the second tab body 21 is located in the recess 13. The second direction is perpendicular to the first direction Z.

[0115] Optionally, the second tab body 21 and the side wall of the recess 13 can be in contact, or the second tab body 21 and the side wall of the recess 13 can have a gap. It can be understood that when the second tab body 21 and the side wall of the recess 13 are in contact, an insulating material is arranged between the second tab body 21 and the side wall of the recess 13.

[0116] In the technical scheme of the embodiment, the recess 13 is arranged, and the second tab body 21 is accommodated in the recess 13, so as to shorten the distance between the regions of the adjacent two first tabs 10 that exceed the second tab 20, thereby reducing the risk of fracture of the tabs caused by excessively large bending radius of the regions of the adjacent first tabs 10 that exceed the second tab 20 in the preparation process, and improving the reliability of the battery monomer 110.

[0117] FIG. 8 is a structural schematic diagram of a first tab in a battery monomer according to an embodiment of the present application.

[0118] In some optional embodiments, referring to FIGS. 7 and 8, the first tab body 11 includes a first current collector 111, a first active material layer 112, and a support structure 113. The first tab 12 is connected to the first current collector 111, the first active material layer 112 is arranged on the surface of the first current collector 111, the support structure 113 is connected to the first active material layer 112 and arranged in the circumferential direction of the first tab body 11, and at least part of the support structure 113 protrudes from the surface of the first active material layer 112 away from the first current collector 111. The support structure 113 and the first active material layer 112 enclose the recess 13.

[0119] In some examples, the first tab body 11 includes a first current collector 111 having two opposite surfaces in a thickness direction thereof, a first active material layer 112 disposed on either or both of the two opposite surfaces of the first current collector 111, and a support structure 113 disposed on either or both of the two opposite surfaces of the first current collector 111.

[0120] The first tab 12 is connected to a peripheral side of the first current collector 111, and the second tab 22 is connected to a peripheral side of the second current collector 211. Optionally, the first tab 12 and the second tab 22 can be located on the same side of the electrode assembly 102, or the first tab 12 and the second tab 22 can be located on different sides of the electrode assembly 102.

[0121] In some examples, the support structure 113 can be located on a side of the first active material layer 112 facing away from the first current collector 111. In other examples, the first current collector 111 has an uncoated region and a coated region, the support structure 113 is disposed on the uncoated region, and the first active material layer 112 is disposed on the coated region. Optionally, a side wall of the support structure 113 and a side wall of the first active material layer 112 can be disposed in abutment with each other, or a gap can be formed between the side wall of the support structure 113 and the side wall of the first active material layer 112.

[0122] The support structure 113 is disposed along a circumferential direction of the first tab body 11. It can be understood that the first tab body 11 has an edge, and the support structure 113 is located on the edge of the first tab body 11 and extends along the edge of the first tab body 11. For example, the first tab body 11 has a rectangular shape, and the support structure 113 forms a rectangular frame around the edge of the rectangular shape. Optionally, the support structure 113 can be a continuous structure, or the support structure 113 can be a plurality of sub-structures disposed at intervals, and the plurality of sub-structures are located on different edges of the rectangular shape.

[0123] In some embodiments, the support structure 113 is protruded from the surface of the first active material layer 112 opposite to the first current collector 111. In other embodiments, a portion of the support structure 113 is protruded from the surface of the first active material layer 112 opposite to the first current collector 111, another portion of the support structure 113 can be flush with the surface of the first active material layer 112 opposite to the first current collector 111, or the surface of the first active material layer 112 opposite to the first current collector 111 is protruded from the other portion of the support structure 113. Of course, the other portion of the support structure 113 can include two sub-portions, one of which is flush with the surface of the first active material layer 112 opposite to the first current collector 111, and the surface of the first active material layer 112 opposite to the first current collector 111 is protruded from the other sub-portion.

[0124] The support structure 113 and the first active material layer 112 enclose the recess 13, which can be understood as that the support structure 113 forms the side wall of the recess 13, and the first active material layer 112 forms the bottom wall of the recess 13. Of course, one portion of the support structure 113 can also form the bottom wall of the recess 13.

[0125] Optionally, the support structure 113 can be made of insulating material.

[0126] Optionally, the support structure 113 can be located at the root of the first tab 12, and the support structure 113 can support the first tab 12, thereby reducing the risk of excessive bending angle of the first tab 12 or even breakage of the first tab 12 in the preparation process; and the support structure 113 can also support the second tab 22, thereby reducing the risk of excessive bending angle of the second tab 22 or even breakage of the second tab 22 in the preparation process.

[0127] In these optional embodiments, by providing the support structure 113, the distance between the overhang regions of two adjacent first tabs 10 is shortened, thereby reducing the risk of breakage of the overhang region of the first tab 10 in the preparation process and improving the reliability of the battery cell 110.

[0128] In some optional embodiments, referring to FIGS. 7 and 8, the support structure 113 includes a first portion 113a and a second portion 113b, the second portion 113b is protruded from the first portion 113a along the first direction Z, the second portion 113b forms at least part of the side wall of the recess 13, and the edge of the second tab body 21 is located within the projection of the first portion 113a along the first direction Z.

[0129] Optionally, the first portion 113a and the second portion 113b can be a laminated structure. Alternatively, the first portion 113a and the second portion 113b can also be an integral structure.

[0130] In some embodiments, the second part 113b protrudes from the first part 113a, and the second part 113b forms a side wall of the recess 13, and the first part 113a and the first active material layer 112 form a bottom wall of the recess 13.

[0131] In some embodiments, the second part 113b can form a side wall of the recess 13. In other embodiments, the second part 113b forms part of a side wall of the recess 13, and the first part 113a can form another part of the side wall of the recess 13. Alternatively, the support structure 113 further comprises a third part located on a side of the second part 113b away from the first part 113a, and the second part 113b and the third part jointly form a side wall of the recess 13, and a step surface is provided between the third part and the second part 113b, and a portion of the second tab body 21 is lapped on the step surface. For example, a side of the second tab body 21 along the thickness direction of the second tab body 21 has the second active material layer 212 located in the recess 13 and close to the first active material layer 112, and a portion of the second current collector 211 and the second active material layer 212 on a side of the second current collector 211 away from the first active material layer 112 are lapped on the step surface, so as to increase the area of the active material layer on the side of the second tab 20. When the first tab 10 is a positive electrode tab and the second tab 20 is a negative electrode tab, the area of the active material layer of the second tab 20 can be greater than the area of the active material layer of the first tab 10, thereby reducing the risk of ion precipitation of the battery monomer 110.

[0132] It can be understood that when the first tab 10 is a positive electrode tab and the second tab 20 is a negative electrode tab, the edge of the second tab body 21 has a positive projection along the first direction Z located in the positive projection of the first part 113a along the first direction Z, which can increase the area of the active material layer of the second tab 20 and reduce the risk of ion precipitation of the battery monomer 110.

[0133] In these optional embodiments, through the above arrangement, the overall area of the second tab 20 can be increased, and the risk of ion precipitation of the battery monomer 110 can be reduced. The risk of short circuit of the battery monomer 110 caused by the burr of the edge of the second tab 20 and the lapping of the first tab 10 can be reduced.

[0134] In some optional embodiments, referring to FIG. 7, the first active material layer 112 comprises a first active material body 112a and a thinned part 112b, the thinned part 112b is arranged along the circumference of the first active material body 112a, and at least part of the first part 113a is located on a side of the thinned part 112b away from the first current collector 111.

[0135] Optionally, the thickness of the first active material body 112a is greater than the thickness of the thinned part 112b.

[0136] Optionally, the thickness of the thinning portion 112b can gradually increase in a direction close to the first active material body 112a.

[0137] Optionally, the orthographic projection of the first sub-portion 113a along the first direction Z and the orthographic projection of the thinning portion 112b along the first direction Z can be arranged to overlap. For example, the orthographic projection of the first sub-portion 113a along the first direction Z and the orthographic projection of the thinning portion 112b along the first direction Z can be arranged to overlap.

[0138] Optionally, a portion of the first sub-portion 113a can be located on a side of the thinning portion 112b facing away from the first current collector 111, and another portion of the first sub-portion 113a can be arranged to abut against a side wall of the thinning portion 112b.

[0139] In these optional embodiments, by the above arrangement, it is beneficial to increase the connection area of the support structure 113 and the first tab body 11, thereby reducing the possibility of separation of the support structure 113 and the first tab body 11, and it is beneficial to disperse the interaction force when the support structures 113 abut against each other to the first tab body 11, thereby reducing the risk that the abutment of the support structures 113 against each other causes the support structures 113 to press and break the first tab body 11.

[0140] In some optional embodiments, referring to FIG. 7, a side surface of the first sub-portion 113a facing away from the first current collector 111 is arranged flush with a side surface of the first active material body facing away from the first current collector 111, so as to reduce the possibility that the edge thickness of the first tab 10 and the second tab 20 after being stacked is greater than the thickness of the central region of the first tab 10 and the second tab 20, improve the thickness uniformity of the electrode assembly 102, and improve the reliability of the battery cell 110.

[0141] In some optional embodiments, referring to FIG. 7, the number of support structures 113 includes two, and the two support structures 113 are arranged on opposite sides of the first current collector 111 along the first direction Z.

[0142] Optionally, the orthographic projection of the two support structures 113 along the first direction Z can be arranged to overlap. Of course, the orthographic projection of the two support structures 113 along the first direction Z can also be arranged to overlap or be spaced apart.

[0143] It can be understood that the plurality of first pole pieces 10 and the plurality of second pole pieces 20 are arranged in an overlapping manner, one second pole piece 20 is arranged between two first pole pieces 10, and the opposite support structures 113 of the two first pole pieces 10 are buckled to form an accommodation space, and the second pole piece 20 can be accommodated in the accommodation space. Alternatively, the two support structures 113 arranged opposite to each other of the two first pole pieces 10 can be arranged abuttingly or can be arranged spacedly. Alternatively, the two support structures 113 arranged opposite to each other of the two first pole pieces 10 can be provided with a fitting structure, for example, one of the support structures 113 is provided with a limiting groove, and the other support structure 113 can be provided with a limiting column, and in the preparation process, the limiting column can be inserted into the limiting groove and moved in the first direction Z in the limiting groove. Alternatively, the limiting column can also play a guiding role to reduce the alignment accuracy of the two opposite support structures 113.

[0144] In the embodiment of the application, the support structure 113 is arranged on both sides of the first current collector 111, so that when the overhang regions of the two first pole pieces 10 are relatively close, the support structures 113 on the two first pole pieces 10 disperse the interaction force to the two pole pieces, further reducing the possibility of fracture of the overhang region in the preparation process, and improving the reliability of the battery monomer 110.

[0145] In some alternative embodiments, please refer to FIG. 5 and FIG. 7, the size of the second part 113b in the first direction Z is equal to half of the size of the second pole piece 20 in the first direction Z, so that after the support structures 113 on the two first pole pieces 10 are buckled, the second pole piece 20 is accommodated in the recess 13 of the two first pole pieces 10, thereby reducing the possibility of misalignment of the first pole piece 10 and the second pole piece 20.

[0146] Exemplarily, the size of the second part 113b in the first direction Z is d, and the size of the second pole piece 20 in the first direction Z is D, and d and D satisfy the relationship d=0.5D.

[0147] FIG. 9 is another enlarged structure schematic view of P in FIG. 6.

[0148] In some alternative embodiments, please refer to FIG. 9, the support structure 113 is located on one side of the first current collector 111 in the first direction Z.

[0149] It can be understood that the plurality of first pole pieces 10 and the plurality of second pole pieces 20 are arranged in an overlapping manner, one second pole piece 20 is arranged between two first pole pieces 10, the support structure 113 of one of the first pole pieces 10 contains the second pole piece 20, and the side of the other first pole piece 10 without the support structure 113 is arranged towards the support structure 113 of one of the first pole pieces 10. Here, the "side without the support structure 113" refers to the side of the other first pole piece 10 opposite to the side where the support structure 113 is arranged. Alternatively, the surface of the side of the other first pole piece 10 without the support structure 113 and the support structure 113 of one of the first pole pieces 10 can be in abutment with each other, or can be arranged with a gap. It should be noted that when the support structure 113 is only arranged on one side of the first current collector 111 along the first direction Z, an insulating film layer needs to be arranged on the side without the support structure 113 in the area abutting the support structure 113, so as to reduce the risk that the active material layer area of the side without the support structure 113 exceeds the active material layer area of the second pole piece 20 and causes ion precipitation.

[0150] The embodiment of the present application is beneficial to reducing the preparation process of the first pole piece 10, improving the production efficiency of the first pole piece 10, and reducing the manufacturing cost of the battery monomer 110 by arranging the support structure 113 on one side of the first current collector 111.

[0151] In some optional embodiments, referring to FIG. 9, the dimension of the second part 113b along the first direction Z is equal to the dimension of the second pole piece 20 along the first direction Z, which is beneficial to reducing the redundant arrangement of the support structure 113, and at the same time, enabling the support structure 113 on the first pole piece 10 to support the overhang area of the adjacent first pole piece body 11, reducing the possibility of bending of the first pole piece 10 in the preparation process, and improving the reliability of the battery monomer 110.

[0152] For example, the dimension of the second part 113b along the first direction Z is d, the dimension of the second pole piece 20 along the first direction Z is D, and d and D satisfy the relationship d=D.

[0153] FIG. 10 is an exploded schematic view of an electrode assembly in a battery monomer according to an embodiment of the present application. FIG. 11 is an enlarged structure schematic view of Q in FIG. 10.

[0154] In some optional embodiments, referring to FIG. 10 and FIG. 11, the second tab 22 protrudes from the edge of the second pole piece body 21, the second part 113b is provided with an opening K1, and the second tab 22 protrudes from the recess 13 through the opening.

[0155] It can be understood that the second tab 20 includes a second tab body 21 and a second lug 22, the second lug is protrudingly arranged at the peripheral side of the second tab body 21, the second tab body 21 is accommodated in the recess 13, the second sub-part 113b is arranged at the opening K1 to form a gap on the side wall of the recess 13, and the second lug 22 can protrude into the recess 13 through the opening K1 to reduce the possibility of interference between the side wall of the recess and the second lug 22.

[0156] Optionally, the shape of the second sub-part 113b in the orthographic projection in the first direction Z can be a continuous structure.

[0157] In some optional embodiments, the first tab 10 is a positive tab, and the second tab 20 is a negative tab. In combination with the above technical solutions, the edge of the second tab body 21 in the orthographic projection in the first direction Z is arranged in the orthographic projection of the first sub-part 113a in the first direction Z, which is beneficial to reduce the risk of ion precipitation of the battery monomer 110 and the risk of short circuit of the battery monomer 110 caused by the burr of the edge of the second tab body 21 and the lap joint of the first tab 10.

[0158] FIG. 12 is a structural schematic diagram of a second tab in a battery monomer according to an embodiment of the present application.

[0159] In some optional embodiments, referring to FIG. 12, the surface of the second tab 20 is provided with a solid-state electrolyte layer 23, and the solid-state electrolyte layer covers the second tab body 21 and at least part of the second lug 22.

[0160] Optionally, the solid-state electrolyte layer 23 covers the second active material layer 212.

[0161] Optionally, the solid-state electrolyte layer 23 can also cover the root of the second lug 22. Optionally, the solid-state electrolyte layer 23 can extend from the root of the second lug 22 to a preset position on the top of the second lug. Here, the "root" refers to the region where the second lug 22 is connected to the second tab body 21, and the "top" refers to the side of the second lug 22 away from the second tab body 21.

[0162] In these optional embodiments, by covering the second tab body 21 and at least part of the second lug 22 with the solid-state electrolyte layer 23, the separation effect of the solid-state electrolyte layer 23 on the oppositely arranged first active material layer 112 and second active material layer 212 is improved, the possibility of short circuit of the oppositely arranged first active material layer 112 and second active material layer 212 is reduced, and the risk of short circuit of the battery monomer 110 is reduced, thereby improving the reliability of the battery monomer.

[0163] In a second aspect, the embodiments of the present application provide a battery device 100, which includes the battery monomer 110 in any of the foregoing embodiments.

[0164] In a third aspect, the embodiments of the present application provide a power utilization device, comprising the battery device 100 in any of the foregoing embodiments, and the battery device is configured to provide electric energy.

[0165] According to some embodiments of the present application, referring to FIGS. 5-8 and 10-12, the battery cell 110 comprises a housing 101 and an electrode assembly 102 accommodated in the housing, the electrode assembly comprises a plurality of first pole pieces 10 and a plurality of second pole pieces 20, the first pole pieces 10 and the second pole pieces 20 are alternately stacked along a first direction Z, and the first pole pieces 10 and the second pole pieces 20 are opposite in polarity; the first pole piece 10 comprises a first pole piece body 11 and a first tab 12, the first tab 12 protrudes from an edge of the first pole piece body 11, and the first pole piece body 11 is provided with a recess 13 on at least one side thereof along the first direction Z; the second pole piece 20 comprises a second pole piece body 21 and a second tab 22, at least part of the second pole piece body 21 is accommodated in the recess 13, and a projection of the second pole piece body 21 along the first direction Z is located within a projection of the recess 13 along the first direction Z. The first pole piece 10 is a positive pole piece.

[0166] The first pole piece body 11 comprises a first current collector 111, a first active material layer 112, and a support structure 113, the first tab 12 is connected to the first current collector 111, the first active material layer 112 is arranged on a surface of the first current collector 111, and the support structure 113 is connected to the first active material layer 112 and arranged along a circumferential direction of the first pole piece body 11. The support structure 113 comprises a first part 113a and a second part 113b, the second part 113b protrudes from the first part 113a along the first direction Z, and the second part 113b forms at least part of a side wall of the recess 13, and a projection of an edge of the second pole piece body 21 along the first direction Z is located within a projection of the first part 113a along the first direction Z.

[0167] The first active material layer 112 comprises a first active material body 112a and a thinned part 112b, the thinned part 112b is arranged along a circumferential direction of the first active material body 112a, and at least part of the first part 113a is located on a side of the thinned part 112b away from the first current collector 111. A side surface of the first part 113a away from the first current collector 111 is arranged flush with a side surface of the first active material body away from the first current collector 111.

[0168] The number of the support structures 113 comprises two, and the two support structures 113 are arranged on opposite sides of the first current collector 111 along the first direction Z. A dimension of the second part 113b along the first direction Z is equal to half of a dimension of the second pole piece 20 along the first direction Z.

[0169] The second tab 22 protrudes from an edge of the second pole piece body 21, the second part 113b is provided with an opening K1, and the second tab 22 protrudes from the recess 13 through the opening.

[0170] The surface of the second tab 20 is provided with a solid-state electrolyte layer 23, which covers the second tab body 21 and at least part of the second lug 22.

[0171] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the same. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for part or all of the technical features. Such modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and the description of the present application. In particular, as long as there is no structural conflict, each technical feature mentioned in each embodiment can be combined in any way. The present 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 battery cell, comprising a housing and an electrode assembly accommodated in the housing, the electrode assembly comprising a plurality of first electrode tabs and a plurality of second electrode tabs, the first electrode tabs and the second electrode tabs being alternately stacked along a first direction, the first electrode tabs and the second electrode tabs being opposite in polarity; the first electrode tab comprising a first electrode tab body and a first electrode lug, the first electrode lug protruding from an edge of the first electrode tab body, the first electrode tab body being provided with a recess at least on one side along the first direction; the second electrode tab comprising a second electrode tab body and a second electrode lug, at least a portion of the second electrode tab body being accommodated in the recess, and a projection of the second electrode tab body along the first direction being located within a projection of the recess along the first direction.

2. The battery cell of claim 1, wherein, the first electrode tab body comprising a first current collector, a first active material layer, and a support structure, the first electrode lug being connected to the first current collector, the first active material layer being disposed on a surface of the first current collector, the support structure being connected to the first active material layer and disposed along a circumferential direction of the first electrode tab body, at least a portion of the support structure protruding from a surface of the first active material layer away from the first current collector; the support structure and the first active material layer enclosing the recess.

3. The battery cell of claim 2, wherein, the support structure comprising a first portion and a second portion, the second portion protruding from the first portion along the first direction, the second portion forming at least a portion of a sidewall of the recess, a projection of an edge of the second electrode tab body along the first direction being located within a projection of the first portion along the first direction.

4. The battery cell of claim 3, wherein, the first active material layer comprising a first active material body and a thinned portion, the thinned portion being disposed along a circumferential direction of the first active material body, at least a portion of the first portion being located on a side of the thinned portion away from the first current collector.

5. The battery cell of claim 4, wherein, a side surface of the first portion away from the first current collector is disposed flush with a side surface of the first active material body away from the first current collector.

6. The battery cell of any one of claims 3-5, wherein, the battery cell comprises two support structures, the two support structures being disposed on opposite sides of the first current collector along the first direction.

7. The battery cell of claim 6, wherein, a dimension of the second portion along the first direction is equal to half of a dimension of the second electrode tab along the first direction.

8. The battery cell of any one of claims 3-5, wherein, the support structure is located on one side of the first current collector along the first direction.

9. The battery cell of claim 8, wherein, a dimension of the second portion along the first direction is equal to a dimension of the second electrode tab along the first direction.

10. The battery cell of any one of claims 3-9, wherein, the second electrode lug protrudes from an edge of the second electrode tab body, the second portion being provided with an opening, the second electrode lug protruding from the recess through the opening.

11. The battery cell of any one of claims 1-10, wherein, the first electrode tab is a positive electrode tab.

12. The battery cell of any one of claims 1-11, wherein, a surface of the second electrode tab is provided with a solid-state electrolyte layer, the solid-state electrolyte layer covering the second electrode tab body and at least a portion of the second electrode lug. 13.A battery device, comprising the battery cell according to any one of claims 1 to 12. 14.An electric device, comprising the battery device according to claim 13, the battery device being configured to provide electric energy.

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