Battery cell, battery and electric device

Abstract

The utility model discloses a battery monomer, a battery and a power utilization device. The battery cell includes a case, a first electrode assembly, and a second electrode assembly. The first electrode assembly is arranged in the shell and comprises a plurality of first pole pieces which are arranged in a stacked mode. The second electrode assembly is arranged in the shell; the second electrode assembly comprises a wound second pole piece; wherein the first electrode assembly is arranged between the shell and the second electrode assembly. The laminated first electrode assembly and the wound second electrode assembly are simultaneously arranged in the shell, the internal space of the shell is fully utilized to improve the energy density of the battery monomer, the first electrode assembly is arranged between the second electrode assembly and the shell, and a gap is formed between the second electrode assembly and the shell, so that the energy density of the battery monomer is improved. The risk of cracking of the winding pole piece caused by friction between the second electrode assembly and the shell is reduced, and the operation stability of the battery monomer is improved.

Description

Technical Field

[0001] The present application relates to the field of batteries, and in particular to a battery cell, a battery and an electrical device. Background Art

[0002] As natural resources are depleted, various fields have conducted in-depth research on devices that can store energy and effectively utilize the stored energy. Battery cells are widely used in renewable energy systems, battery systems, and existing power systems, and various resources are combined to transmit energy.

[0003] At present, in battery cell technology, how to improve the stability of the battery cell operation process is also one of the research issues in this field. Utility Model Content

[0004] In view of the above problems, the present application provides a battery cell, a battery and an electrical device, which can reduce the risk of cracking of the electrode assembly in the battery cell and improve the stability of the operation of the battery cell.

[0005] In a first aspect, the present application provides a battery cell, comprising a housing, a first electrode assembly, and a second electrode assembly. The first electrode assembly is disposed in the housing, and the first electrode assembly comprises a plurality of first electrode sheets stacked in layers. The second electrode assembly is disposed in the housing, and the second electrode assembly comprises a second electrode sheet wound in a winding manner. The first electrode assembly is disposed between the housing and the second electrode assembly.

[0006] In the technical solution of the embodiment of the present application, a stacked first electrode assembly and a wound second electrode assembly are simultaneously arranged in the shell, making full use of the internal space of the shell to improve the energy density of the battery cell, and the first electrode assembly is arranged between the second electrode assembly and the shell to form a gap between the second electrode assembly and the shell, thereby reducing the risk of cracking of the wound pole piece due to friction between the second electrode assembly and the shell, and improving the stability of the operation of the battery cell.

[0007] In some embodiments, the plurality of second pole pieces include a plurality of straight sections and bent sections that are alternately connected and formed by winding, the plurality of straight sections are stacked in sequence along a first direction, and the first electrode assembly is disposed on one side of the second electrode assembly along the first direction. In the above technical solution, the first electrode assembly is disposed on one side of the second electrode assembly in a radial direction, so that a gap can be formed between the housing and the bent section, reducing the risk of cracking of the bent section and improving the stability of the battery cell operation.

[0008] In some embodiments, a plurality of first pole pieces are stacked in sequence along a first direction. In the above technical solution, the stacking direction of the plurality of first pole pieces is the same as the stacking direction of the plurality of straight segments, which can facilitate welding connection between the pole lug of the first electrode assembly and the pole lug of the second electrode assembly, thereby improving the efficiency and convenience of battery cell assembly.

[0009] In some embodiments, the number of first electrode assemblies is two, and the two first electrode assemblies are arranged opposite to each other along the first direction. The two first electrode assemblies can form sufficient deformation space between the second assembly and the shell, reduce the risk of cracking of the bent section of the second electrode assembly, improve the stability of the battery cell operation, and improve the energy density of the battery cell.

[0010] In some embodiments, along the first direction, the orthographic projections of the plurality of first pole pieces on the second pole piece completely fall within the range of the straight section. In the above structure, the space occupied by the first pole piece is reduced, the space between the bent section of the second electrode assembly and the shell is increased, the risk of cracking caused by friction and collision between the bent section and the shell is reduced, and the stability of the battery cell operation is improved.

[0011] In some embodiments, the width of the first pole piece along the second direction is equal to the width of the straight section along the second direction, and the second direction intersects the first direction. In the above structure, the width of the second pole piece along the second direction is increased, the area of ​​the electrode assembly is increased, and the energy density of the battery cell is improved.

[0012] In some embodiments, the first electrode assembly includes a first main body and a first pole ear extending from the first main body along a third direction, and the third direction intersects with the plane where the first direction and the second direction are located. The second electrode assembly includes a second main body and a second pole ear extending from the second main body along the third direction, and the second pole ear is stacked with the first pole ear. The battery cell also includes a connector, which is connected to the first main body and the second main body along the third direction away from the first pole ear and the second pole ear.

[0013] In the above technical solution, a connector is provided at one end of the first electrode assembly and the second electrode assembly away from the pole ear, which can improve the stability of the connection between the first electrode assembly and the second electrode assembly, and can guide the first electrode assembly and the second electrode assembly into the shell, thereby improving the assembly efficiency of the battery cell.

[0014] In some embodiments, along the first direction, the thickness L1 of the first electrode assembly is: 0.5 mm ≤ L1 ≤ 10.0 mm. Along the first direction, the thickness L2 of the straight section of the second electrode assembly is: 10.0 mm ≤ L2 ≤ 50.0 mm. In the above structure, the thickness of the first electrode assembly is lower than the thickness of the second electrode assembly, which can increase the number of windings of the wound electrode assembly, reasonably utilize the internal space of the shell, and improve the energy density of the battery cell.

[0015] In a second aspect, the present application provides a battery, which includes the battery cell in the above embodiment.

[0016] In a third aspect, the present application provides an electrical device, which includes the battery in the above embodiment, and the battery is used to provide electrical energy.

[0017] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The features, advantages and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

[0019] Figure 1 A schematic diagram of the structure of a vehicle according to an embodiment of the present application;

[0020] Figure 2 This is a schematic diagram of the exploded structure of a battery according to an embodiment of the present application;

[0021] Figure 3 A schematic diagram of the structure of a battery cell according to an embodiment of the present application;

[0022] Figure 4 A schematic diagram of the structure of a battery cell according to another embodiment of the present application;

[0023] Figure 5 This is a schematic structural diagram of a battery cell according to another embodiment of the present application;

[0024] Figure 6 This is a schematic structural diagram of a battery cell according to another embodiment of the present application.

[0025] DETAILED DESCRIPTION OF REFERENCE NUMERALS

[0026] 1. Vehicle; X, first direction; Y, second direction; Z, third direction; 2. Battery; 10. Electrode assembly; 101. First electrode assembly; 102. Second electrode assembly; 103. Straight section; 104. Bend section; 105. First pole piece; 106. Second pole piece; 107. First main body; 108. First pole ear; 109. Second main body; 110. Second pole ear; 20. Shell; 30. End cover; 40. Outer shell; 3. Controller; 4. Motor; 5. Box; 51. First part; 52. Second part; 53. Accommodation space; 6. Connector; 601. First connecting part; 602. Second connecting part; 603. Third connecting part; 7. Battery cell. DETAILED DESCRIPTION

[0027] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0029] 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 "multiple" is more than two, unless otherwise clearly and specifically defined.

[0030] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0031] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0032] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0033] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0034] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0035] Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of a vehicle provided for some embodiments of the present application. Vehicle 1 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 2 is provided inside the vehicle 1, and the battery 2 may be provided at the bottom, the head or the tail of the vehicle 1. The battery 2 may be used to power the vehicle 1, for example, the battery 2 may be used as an operating power source for the vehicle 1. The vehicle 1 may also include a controller 3 and a motor 4, and the controller 3 is used to control the battery 2 to power the motor 4, for example, for the starting, navigation and working power requirements of the vehicle 1 during driving.

[0036] In some embodiments of the present application, the battery 2 can be used not only as an operating power source for the vehicle 1, but also as a driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0037] In some embodiments, the battery 2 may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0038] Please refer to Figure 2 , Figure 2This is an exploded view of a battery provided in one embodiment of the present application. The battery 2 includes a box body 5 and a battery cell 7, and the battery cell 7 is accommodated in the box body 5. The box body 5 is used to provide a storage space for the battery cell 7, and the box body 5 can adopt a variety of structures.

[0039] In some optional embodiments, the box body 5 includes a first part 51 and a second part 52, the first part 51 and the second part 52 cover each other, and the first part 51 and the second part 52 jointly define a storage space 53 for accommodating the battery cell 7. The second part 52 can be a hollow structure with one end open, and the first part 51 can be a plate-like structure, and the first part 51 covers the open side of the second part 52, so that the first part 51 and the second part 52 jointly define the storage space 53; the first part 51 and the second part 52 can also be hollow structures with one side open, and the open side of the first part 51 covers the open side of the second part 52. Of course, the box body 5 formed by the first part 51 and the second part 52 can be a variety of shapes, such as a cylinder, a cuboid, etc.

[0040] In some embodiments, the box 5 can be used as part of the chassis structure of the vehicle 1. For example, part of the box 5 can become at least a part of the floor of the vehicle 1, or part of the box 5 can become at least a part of the cross beam and longitudinal beam of the vehicle 1.

[0041] In the battery 2, there can be multiple battery cells 7, and the multiple battery cells 7 can be connected in series, in parallel, or in mixed connection. Mixed connection means that the multiple battery cells 7 are both connected in series and in parallel. The multiple battery cells 7 can be directly connected in series, in parallel, or in mixed connection, and then the whole formed by the multiple battery cells 7 is accommodated in the box 5. Of course, the battery 2 can also be a battery module formed by connecting multiple battery cells 7 in series, in parallel, or in mixed connection, and then the multiple battery modules are connected in series, in parallel, or in mixed connection to form a whole, and accommodated in the box 5. The battery 2 can also include other structures, for example, the battery 2 can also include a converging component for realizing the electrical connection between the multiple battery cells 7.

[0042] Each battery cell 7 may be a secondary battery or a primary battery, or a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited thereto. The battery cell 7 may be cylindrical, flat, rectangular or in other shapes.

[0043] Please refer to Figure 3 , Figure 3 The schematic diagram of the structure of a battery cell 7 provided in one embodiment of the present application. The battery cell 7 refers to the smallest unit constituting the battery 2. Figure 3 The battery cell 7 includes a housing 40, an electrode assembly 10 and other functional components.

[0044] The housing 40 is provided with a housing cavity, and the electrode assembly 10 is accommodated in the housing cavity. The electrode assembly 10 includes a main body and a tab extending from the main body. The main body 11 may include a portion of the positive electrode sheet coated with an active material layer, a component of the negative electrode sheet coated with an active material layer, and a separator, and the active material in the active material layer is used to react with the electrolyte to achieve charging and discharging.

[0045] The housing 40 is a component for accommodating the electrode assembly 10. The housing 40 can be made of various materials, such as copper, iron, aluminum, steel, and aluminum alloy. The housing 40 can be in various shapes, such as a cylinder, a cuboid, etc. The housing 40 in the exemplary figure is a cylinder.

[0046] The outer shell 40 may include an end cap 30 and a shell 20. The end cap 30 refers to a component that covers the opening 22 of the shell 20 to isolate the internal environment of the battery cell 7 from the external environment. Without limitation, the shape of the end cap 30 may be adapted to the shape of the shell 20 to match the shell 20. Optionally, the end cap 30 may be made of a material with a certain hardness and strength (such as an aluminum alloy), so that the end cap 30 is not easily deformed when squeezed or collided, so that the battery cell 7 can have a higher structural strength and the safety performance can also be improved. Functional components such as a pressure relief mechanism, an electrode lead-out piece, etc. may be provided on the end cap 30. The electrode lead-out piece can be used to be electrically connected to the electrode assembly 10 for outputting or inputting electrical energy of the battery cell 7.

[0047] In some embodiments, the end cap 30 may also be provided with a pressure relief mechanism for releasing the internal pressure when the internal pressure or temperature of the battery cell 7 reaches a threshold value. The material of the end cap 30 may also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not impose any special restrictions on this. In some embodiments, an insulating component may also be provided on the inner side of the end cap 30, and the insulating component may be used to isolate the electrical connection components in the housing 20 from the end cap 30 to reduce the risk of short circuit. Exemplarily, the insulating component may be plastic, rubber, etc.

[0048] The housing 20 is a component used to cooperate with the end cap 30 to form the internal environment of the battery cell 7. The formed internal environment can be used to accommodate the electrode assembly 10, the electrolyte and other components. The housing 20 and the end cap 30 can be independent components, and an opening can be set on the housing 20, and the internal environment of the battery cell 7 is formed by covering the opening with the end cap 30.

[0049] In some optional embodiments, the end cap 30 and the shell 20 can also be integrated. Specifically, the end cap 30 and the shell 20 can form a common connection surface before other components are put into the shell. When the interior of the shell 20 needs to be encapsulated, the end cap 30 is covered with the shell 20. The shell 20 can be of various shapes and sizes, such as a rectangular parallelepiped, a cube, a hexagonal prism, etc. Specifically, the shape of the shell 20 can be determined according to the specific shape and size of the electrode assembly 10. The material of the shell 20 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not impose any special restrictions on this.

[0050] The electrode assembly 10 is a component in the battery cell 7 where electrochemical reactions occur. One or more electrode assemblies 10 may be included in the housing 20. The electrode assembly 10 includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell 7, active ions (such as lithium ions) are embedded and removed back and forth between the positive electrode and the negative electrode. The separator is arranged between the positive electrode and the negative electrode, which can prevent the positive and negative electrodes from short-circuiting, and at the same time allow active ions to pass through.

[0051] In some embodiments, the separator is a separator. The present application has no particular restrictions on the type of separator, and any known porous separator with good chemical stability and mechanical stability can be selected. As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic.

[0052] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transmit ions and isolate the positive and negative electrodes.

[0053] In some embodiments, the battery cell 7 further includes an electrolyte, which plays a role in conducting ions between the positive and negative electrodes. The present application has no specific restrictions on the type of electrolyte, which can be selected according to needs. The electrolyte can be liquid, gel or solid.

[0054] The tab protrudes from the separator of the main body, so as to facilitate welding connection with the tabs stacked. Exemplarily, the electrode assembly includes a positive tab and a negative tab, the positive tab may be a portion of the positive electrode sheet not coated with the active material layer, the negative tab may be a portion of the negative electrode sheet not coated with the active material layer, and the positive tab and the negative tab conduct the electric energy generated by the main body.

[0055] The positive electrode tab and the negative electrode tab can be led out from the same end of the main body, or from opposite ends of the main body. At least part of the electrode lead-out member is exposed to the outside of the battery cell 7 to facilitate connection with other components (such as a busbar) to lead out the electrical energy generated by the electrode assembly 10.

[0056] With the development of battery technology, people have put forward higher requirements for the operating stability of battery cells. In related technologies, in the electrode assembly of the battery cell, the electrode assembly formed by winding the pole piece is set in the shell. The wound electrode assembly is in direct contact with the shell and is prone to friction and collision, resulting in cracking of the bent part of the electrode assembly. The cracking of the electrode assembly leads to the operation failure of the battery cell and reduces the stability of the battery cell operation.

[0057] Based on the above situation, an embodiment of the present application provides a battery cell, in which a first electrode assembly arranged in a stacked manner and a second electrode assembly formed by winding are simultaneously arranged in a shell, so as to make full use of the internal space of the shell to improve the energy density of the battery cell, and the first electrode assembly is arranged between the second electrode assembly and the shell to form a gap between the second electrode assembly and the shell, thereby reducing the risk of the second electrode assembly contacting the shell and causing cracking of the wound pole piece, thereby improving the stability of the operation of the battery cell.

[0058] The following is a detailed description of the battery cell provided in the embodiment of the present application in conjunction with the accompanying drawings. Figures 3 to 6 , Figure 3 This is a schematic diagram of the structure of a battery cell according to an embodiment of the present application. Figure 4 This is a schematic diagram of the structure of a battery cell according to another embodiment of the present application. Figure 5 This is a schematic diagram of the structure of a battery cell according to another embodiment of the present application. Figure 6 This is a schematic structural diagram of a battery cell according to another embodiment of the present application.

[0059] As shown in the figure, the embodiment of the present application provides a battery cell 7, including a housing 20, a first electrode assembly 101 and a second electrode assembly 102. The first electrode assembly 101 is disposed in the housing 20, and the first electrode assembly 101 includes a plurality of stacked first pole pieces 105. The second electrode assembly 102 is disposed in the housing 20, and the second electrode assembly 102 includes a wound second pole piece 106. The first electrode assembly 101 is disposed between the housing 20 and the second electrode assembly 102.

[0060] In the technical solution of the embodiment of the present application, a stacked first electrode assembly 101 and a wound second electrode assembly 102 are simultaneously arranged in the shell 20, so as to make full use of the internal space of the shell 20 to improve the energy density of the battery cell 7, and the first electrode assembly 101 is arranged between the second electrode assembly 102 and the shell 20 to form a gap between the second electrode assembly 102 and the shell 20, thereby reducing the risk of the second electrode assembly 102 contacting the shell 20 and causing the wound pole piece to crack, thereby improving the stability of the operation of the battery cell 7.

[0061] In some embodiments of the present application, the plurality of second pole pieces 106 include a plurality of straight segments 103 and bent segments 104 formed by winding and connected alternately, the plurality of straight segments 103 are stacked in sequence along the first direction X, and the first electrode assembly 101 is disposed on one side of the second electrode assembly 102 along the first direction X. In the above technical solution, the first electrode assembly 101 is disposed on one side of the second electrode assembly 102 in the radial direction, so that a gap can be formed between the housing 20 and the bent segment 104, providing space for deformation of the bent segment 104, reducing the risk of cracking of the bent segment 104, and improving the stability of operation of the battery cell 7.

[0062] In some optional embodiments, the first electrode assembly 101 includes N layers of first cathode plates, and the second electrode assembly 102 includes M layers of second cathode plates, wherein N / 20≤M≤N / 5. The above technical solution sets an appropriate thickness, which can increase the thickness of the second electrode assembly 102 and improve the utilization rate of the internal space of the shell 20. At the same time, the appropriate thickness of the first electrode assembly 101 can reduce the risk of the bent section 104 of the second electrode assembly 102 contacting the shell 20, thereby causing the risk of cracking the wound plate, thereby improving the stability of the operation of the battery cell 7.

[0063] In some embodiments of the present application, a plurality of first pole pieces 105 are stacked in sequence along the first direction X. In the above technical solution, the stacking direction of the plurality of first pole pieces 105 is the same as the stacking direction of the plurality of straight sections 103, which can facilitate the connection between the pole lug of the first electrode assembly 101 and the pole lug of the second electrode assembly 102, thereby improving the efficiency and convenience of assembling the battery cell 7.

[0064] like Figure 5 As shown, in some embodiments of the present application, the number of the first electrode assemblies 101 is two, and the two first electrode assemblies 101 are arranged opposite to each other along the first direction X. The two first electrode assemblies 101 can form a sufficient space between the second assembly and the shell 20, reduce the probability of friction between the bending section 104 and the shell 20, reduce the risk of cracking of the bending section 104 of the second electrode assembly 102, improve the stability of the operation of the battery cell 7, and improve the energy density of the battery cell 7.

[0065] In some embodiments of the present application, along the first direction X, the orthographic projections of the plurality of first pole pieces 105 on the second pole piece 106 completely fall within the range of the straight section 103. In the above structure, the space between the bent section 104 of the second electrode assembly 102 and the housing 20 is increased, the risk of collision and cracking caused by pressure between the bent section 104 and the housing 20 is reduced, and the stability of the operation of the battery cell 7 is improved.

[0066] In some embodiments of the present application, the width W1 of the first pole piece 105 along the second direction Y is equal to the width W2 of the straight section 103 along the second direction Y, and the second direction Y intersects the first direction X. In the above structure, the width of the second pole piece 106 along the second direction Y is increased, the area of ​​the electrode assembly 10 is increased, and the energy density of the battery cell 7 is improved.

[0067] like Figure 6 As shown, in some embodiments of the present application, the first electrode assembly 101 includes a first main body 107 and a first pole tab 108 extending from the first main body 107 along a third direction Z, and the third direction Z intersects with the plane where the first direction X and the second direction Y are located. The second electrode assembly 102 includes a second main body 109 and a second pole tab 110 extending from the second main body 109 along the third direction Z, and the second pole tab 110 is stacked with the first pole tab 108. The battery cell 7 also includes a connector 6, which is connected to one end of the first main body 107 and the second main body 109 along the third direction Z away from the first pole tab 108 and the second pole tab 110.

[0068] In the above technical solution, a connector 6 is provided at one end of the first electrode assembly 101 and the second electrode assembly 102 away from the pole ear, which can improve the stability of the connection between the first electrode assembly 101 and the second electrode assembly 102, and can guide the first electrode assembly 101 and the second electrode assembly 102 into the shell, thereby improving the assembly efficiency of the battery cell 7.

[0069] In some optional embodiments, the connector 6 is connected to the adjacent first electrode assembly 101 and the second electrode assembly 102. The above structure can connect the first electrode assembly 101 and the second electrode assembly 102 in advance and then install them into the housing 20 at the same time, thereby improving the structural strength of the connection and improving the assembly efficiency.

[0070] In some optional embodiments, the first connection part 601 attached to the first electrode assembly 101, the second connection part 602 attached to the straight section 103, and the third connection part 603 connected between the first connection part 601 and the second connection part 602. The connection member 6 may include an adhesive tape, and the second connection part 602 is arranged on the straight section 103, which can avoid the risk of the adhesive tape being connected to the bent section 104 and causing the adhesive tape to fall off due to poor adhesion, thereby improving the connection strength.

[0071] In some embodiments of the present application, along the first direction X, the thickness L1 of the first electrode assembly 101 is: 0.5 mm ≤ L1 ≤ 10.0 mm. Along the first direction X, the thickness L2 of the straight section 103 of the second electrode assembly 102 is: 10.0 mm ≤ L2 ≤ 50.0 mm.

[0072] In the above structure, the thickness of the first electrode assembly 101 is lower than that of the second electrode assembly 102, which can increase the number of windings of the wound electrode assembly 10, reasonably utilize the internal space of the shell 20, and improve the energy density of the battery cell 7. At the same time, a proper interval is formed between the second electrode assembly 102 and the shell 20, reducing the risk of cracking caused by friction between the second electrode assembly 102 and the shell 20, and improving the stability of the operation of the battery cell 7.

[0073] The embodiment of the present application provides a battery 2, which includes the battery cell 7 in the above embodiment. The embodiment of the present application also provides an electrical device, which includes the battery 2 in the above embodiment, and the battery 2 is used to provide electrical energy.

[0074] The battery 2 and the electrical device in the embodiment of the present application are provided with a stacked first electrode assembly 101 and a wound second electrode assembly 102 in the shell 20, so as to make full use of the internal space of the shell 20 to improve the energy density of the battery cell 7, and the first electrode assembly 101 is arranged between the second electrode assembly 102 and the shell 20 to form a gap between the second electrode assembly 102 and the shell 20, thereby reducing the risk of the second electrode assembly 102 contacting the shell 20 and causing the wound pole piece to crack, thereby improving the stability of the operation of the battery cell 7.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell (7), characterized in that: include: Housing (20); A first electrode assembly (101) is disposed in the housing (20), wherein the first electrode assembly (101) comprises a plurality of first electrode sheets (105) stacked in layers; A second electrode assembly (102) is disposed in the housing (20), wherein the second electrode assembly (102) comprises a second electrode sheet (106) that is wound; Wherein, the first electrode assembly (101) is arranged between the shell (20) and the second electrode assembly (102).

2. The battery cell (7) according to claim 1, characterized in that: The plurality of second electrode sheets (106) include a plurality of alternately connected straight sections (103) and bent sections (104) formed by winding, the plurality of straight sections (103) are stacked in sequence along a first direction (X), and the first electrode assembly (101) is arranged on one side of the second electrode assembly (102) along the first direction (X).

3. The battery cell (7) according to claim 2, characterized in that: A plurality of the first pole pieces (105) are stacked in sequence along the first direction (X).

4. The battery cell (7) according to claim 2, characterized in that: The number of the first electrode assemblies (101) is two, and the two first electrode assemblies (101) are arranged opposite to each other along the first direction (X).

5. The battery cell (7) according to claim 2, characterized in that: Along the first direction (X), the orthographic projections of the plurality of first pole pieces (105) on the second pole piece (106) completely fall within the range of the straight section (103).

6. The battery cell (7) according to claim 5, characterized in that: The width of the first pole piece (105) along the second direction (Y) is equal to the width of the straight section (103) along the second direction (Y), and the second direction (Y) intersects with the first direction (X).

7. The battery cell (7) according to claim 6, characterized in that: The first electrode assembly (101) comprises a first main body (107) and a first electrode tab (108) extending from the first main body (107) along a third direction (Z), wherein the third direction (Z) intersects with a plane where the first direction (X) and the second direction (Y) are located. The second electrode assembly (102) comprises a second main body (109) and a second electrode tab (110) extending from the second main body (109) along the third direction (Z), wherein the second electrode tab (110) and the first electrode tab (108) are stacked. The battery cell (7) further comprises a connecting member (6), wherein the connecting member (6) is connected to one end of the first main body (107) and the second main body (109) away from the first pole lug (108) and the second pole lug (110) along the third direction (Z).

8. The battery cell (7) according to claim 7, characterized in that: Along the first direction (X), the thickness L1 of the first electrode assembly (101) is: 0.5 mm ≤ L1 ≤ 10.0 mm; Along the first direction (X), the thickness L2 of the straight section (103) of the second electrode assembly (102) is: 10.0 mm≤L2≤50.0 mm.

9. A battery (2), characterized in that: The invention comprises a battery cell (7) as claimed in any one of claims 1 to 8.

10. An electrical device, characterized in that: The electrical device comprises the battery (2) as claimed in claim 9, and the battery (2) is used to provide electrical energy.

Images