Battery monomer, battery device and electric device

Abstract

The utility model provides a battery monomer, a battery device and a power utilization device, a shell of the battery monomer comprises a wall part, a tab is arranged on one side, facing the wall part, of an electrode assembly, an electrode terminal is arranged on the wall part, the tab comprises an extension structure and a bending structure which are connected with each other, the extension structure extends towards the wall part along the thickness direction of the wall part, and the bending structure is arranged on the wall part. The bending structure is bent relative to the thickness direction and is welded with the electrode terminal to form a welding part, and the welding part forms a welding surface on one side, deviating from the bending structure, of the electrode terminal. Due to the fact that the bending structures of the tabs and the electrode terminals are directly welded to form the welding parts, and the welding parts form the welding faces on the sides, deviating from the bending structures, of the electrode terminals, using of adapters is reduced, manufacturing procedures are reduced compared with a scheme using the adapters, manufacturing convenience is improved, and the manufacturing cost is reduced. And the occupation of the adapter on the internal space of the shell is reduced, and the volume of the electrode assembly is increased, so that the energy density of the single battery is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a battery monomer, a battery device and a power utilization device. BACKGROUND

[0002] The battery device has the advantages of high specific energy and high power density, and is widely used in electronic devices and vehicles, such as mobile phones, notebook computers, electric vehicles, electric cars, electric planes, electric ships and electric tools.

[0003] With the continuous expansion of the application range of the battery device, people's requirements for various performances of the battery device are also getting higher and higher. How to improve the energy density of the battery device is increasingly concerned by the technical personnel in the field. CONTENT OF THE INVENTION

[0004] In view of the above problems, the present application provides a battery monomer, a battery device and a power utilization device, which has a higher energy density, which is beneficial to improve the capacity of the battery device.

[0005] In the first aspect, some embodiments of the present application provide a battery monomer, which comprises a shell, an electrode assembly and an electrode terminal, the shell comprises a wall portion, the electrode assembly is arranged in the shell, the electrode assembly is provided with a tab on the side facing the wall portion, and the electrode terminal is arranged on the wall portion. The tab comprises a protruding structure and a bent structure connected to each other, the protruding structure extends along the thickness direction of the wall portion to the wall portion, the bent structure is bent relative to the thickness direction and abuts against the electrode terminal, the bent structure and the electrode terminal are welded to form a welding portion, and the welding portion forms a welding surface on the side of the electrode terminal away from the bent structure.

[0006] In the above structure, since the bent structure of the tab is directly welded with the electrode terminal to form the welding portion, and the welding portion forms the welding surface on the side of the electrode terminal away from the bent structure, not only the use of the adapter is reduced, but also the manufacturing process is reduced compared with the scheme using the adapter, the manufacturing convenience is improved, the occupation of the internal space of the shell by the adapter is further reduced, the volume of the electrode assembly is increased, and the energy density of the battery monomer is improved.

[0007] According to the battery monomer provided by some embodiments of the present application, the tab comprises a plurality of tab layers, the tab layer comprises a protruding portion and a bent portion connected to each other, the protruding portions of the plurality of tab layers are stacked to form the protruding structure, and the bent portions of adjacent tab layers are stacked in the thickness direction to form the bent structure. In the bent structure, the number of layers of the bent portions stacked in the thickness direction is D, and D≥3, so that the bent structure has a sufficient number of layers of the bent portions, the tab has sufficient structural strength and thickness, and the tab is not easy to be welded through when the electrode terminal is welded with the tab, which is beneficial to improve the welding quality of the electrode terminal and the tab.

[0008] According to the battery cell provided by some embodiments of the present application, the projection of the electrode terminal along the thickness direction falls within the projection range of the bending structure, so that the electrode terminal can be connected with the tab through the connection with the bending structure.

[0009] According to the battery cell provided by some embodiments of the present application, the projection of the bending structure along the thickness direction exceeds the projection range of the electrode terminal. By making the projection of the bending structure along the thickness direction exceed the projection range of the electrode terminal along the thickness direction, the bending structure has a larger area to adapt to the relative position fluctuation of the tab and the electrode terminal caused by the manufacturing tolerance and the assembly tolerance.

[0010] According to the battery cell provided by some embodiments of the present application, the size of the projection of the bending structure along the thickness direction in the first direction is B, the size of the projection of the electrode terminal along the thickness direction in the first direction is C, 5%≤(B-C) / C≤20%, and the first direction is perpendicular to the thickness direction, so that the projection of the bending structure along the thickness direction in the first direction can exceed the appropriate size of the projection of the electrode terminal along the thickness direction, not only making the bending structure have sufficient excess size to adapt to the relative position fluctuation of the tab and the electrode terminal caused by the manufacturing tolerance and the assembly tolerance, but also making the bending structure not cause the waste of the size of the tab in the first direction due to excessive size.

[0011] According to the battery cell provided by some embodiments of the present application, the size of the extension structure extending along the thickness direction is E, 1.5mm≤E≤8mm, so that the tab has a suitable size in the thickness direction, not only making the size of the tab in the thickness direction not too large to occupy more space, but also making the tab be able to extend a sufficient size from the electrode body to be connected with the electrode terminal.

[0012] According to the battery cell provided by some embodiments of the present application, 2mm≤E≤6mm.

[0013] According to the battery cell provided by some embodiments of the present application, in the thickness direction, the ratio of the maximum number of layers of the bending part to the total number of layers of the tab layer is A, 15%≤A≤30%, not only making the maximum number of layers of the bending part in the thickness direction sufficient to make the bending structure of the tab have a certain structural strength and thickness to reduce the possibility of welding through, but also making the maximum number of layers of the bending part in the thickness direction not too much to make the bending structure occupy too much space in the thickness direction.

[0014] According to the battery cell provided by some embodiments of the present application, the bending part is configured in a zigzag shape, so that the bending part can be bent more easily relative to the extension part, which is conducive to reducing the difficulty of bending the multi-layer tab layer to form the bending structure.

[0015] According to the battery cell provided by some embodiments of the present application, the battery cell further comprises a terminal cover plate connected to the electrode terminal, at least part of the terminal cover plate is located on the side of the electrode terminal away from the tab and covers the welding surface, which not only reduces the possibility of the welding part contacting rainwater, but also reduces the possibility of the welding part being corroded, and the terminal cover plate can be used as a part in contact with the charging and discharging device, thereby reducing the wear of the electrode terminal.

[0016] According to the battery cell provided by some embodiments of the present application, the side of the electrode terminal away from the tab is provided with a first recess, and the bottom wall of the first recess is welded to the bending structure, so that the thickness of the area of the electrode terminal corresponding to the first recess is thinned, which facilitates the melting of the material on the bottom wall of the first recess during welding, and saves the energy consumption during welding.

[0017] According to the battery cell provided by some embodiments of the present application, at least part of the terminal cover plate is located in the first recess, so that at least part of the terminal cover plate is inserted into the first recess, thereby improving the connection firmness of the terminal cover plate and the first recess.

[0018] According to the battery cell provided by some embodiments of the present application, a step protruding into the first recess is arranged on the side wall of the first recess, and the terminal cover plate located in the first recess abuts against the step, so that the terminal cover plate can be positioned by abutting against the step in the first recess during insertion into the first recess.

[0019] According to the battery cell provided by some embodiments of the present application, the wall portion is provided with a through hole penetrating in the thickness direction, the electrode terminal comprises a main body structure and a protruding structure connected in the thickness direction, in the radial direction of the through hole, the main body structure protrudes from the protruding structure, the main body structure covers the through hole and is located on the side of the wall portion away from the electrode assembly, and the protruding structure penetrates through the through hole, and part of the protruding structure is located on the side of the wall portion facing the electrode assembly and abuts against the bending structure. By making the protruding structure penetrate through the through hole and part of the protruding structure located on the side of the wall portion facing the electrode assembly and abutting against the bending structure, part of the protruding structure protrudes to the side of the wall portion facing the electrode assembly, which facilitates abutting against the bending structure and connecting the bending structure and the protruding structure.

[0020] According to the battery cell provided by some embodiments of the present application, the battery cell further comprises a first insulating member connected to the wall portion, the first insulating member isolates the wall portion from the electrode terminal, which not only enables the first insulating member to seal the gap between the electrode terminal and the wall portion, but also isolates the wall portion from the electrode terminal, so that the wall portion is not electrified and is less likely to be electrically connected to external devices.

[0021] According to the battery cell provided by some embodiments of the present application, the wall portion is recessed inwardly from the surface of the electrode assembly to form a second recess, the second recess is communicated with the through hole, the reinforcing structure is protruded from the outer circumferential surface of the extending structure, the reinforcing structure is located in the second recess and spaced from the main body structure in the thickness direction, and the first insulating member covers the reinforcing structure. Since the reinforcing structure protruded from the outer circumferential surface of the extending structure increases the contact area between the electrode terminal and the first insulating member, the sealing effect of the first insulating member on the space between the electrode terminal and the inner wall of the through hole is improved.

[0022] According to the battery cell provided by some embodiments of the present application, the reinforcing structure is provided in plurality, the plurality of reinforcing structures are arranged in the circumferential direction of the extending structure, so that the first insulating member can uniformly improve the sealing effect on the space between the electrode terminal and the inner wall of the through hole under the action of the plurality of reinforcing structures.

[0023] According to the battery cell provided by some embodiments of the present application, the electrode assembly is provided in plurality, the plurality of electrode assemblies are arranged in the first direction, the tabs of the plurality of electrode assemblies are arranged in the first direction, the electrode terminal is welded with the bent structure of the plurality of tabs, and the first direction is perpendicular to the thickness direction. By arranging the tabs of the plurality of electrode assemblies in the second direction, the electrode terminal can be conveniently connected with the tabs of the plurality of electrode assemblies. By welding the electrode terminal with the bent structure of the plurality of tabs, the plurality of electrode assemblies can be stably connected with the electrode terminal.

[0024] According to the battery cell provided by some embodiments of the present application, the projection of the tab in the thickness direction is rectangular. By setting the projection of the tab in the thickness direction as rectangular, the electrode assembly in the battery cell can be a laminated structure. Each layer of the laminated structure of the electrode assembly extends a tab layer.

[0025] According to the battery cell provided by some embodiments of the present application, the shell is configured as a cuboid structure, so that the battery cell is a cuboid battery cell.

[0026] According to the battery cell provided by some embodiments of the present application, the shell includes a shell body and a cover body, the shell body forms a cavity with an opening, the electrode assembly is located in the cavity, and the cover body covers the opening and is configured as a wall portion.

[0027] In a second aspect, some embodiments of the present application further provide a battery device, which includes the battery cell provided by any of the technical solutions.

[0028] In a third aspect, some embodiments of the present application further provide a power consumption device, which includes the battery device provided by the technical solutions, and the battery device is used for providing electric energy.

[0029] The technical solutions provided by the embodiments of the present application at least have the following beneficial effects:

[0030] The embodiment of the present application provides a battery monomer, which comprises a shell, an electrode assembly and an electrode terminal, the shell comprises a wall part, the electrode assembly is arranged in the shell, a tab is arranged on the side of the electrode assembly facing the wall part, the electrode terminal is arranged on the wall part, the tab comprises a protruding structure and a bending structure connected with each other, the protruding structure extends to the wall part along the thickness direction of the wall part, the bending structure is bent relative to the thickness direction and abuts against the electrode terminal, the bending structure is welded with the electrode terminal to form a welding part, and the welding part forms a welding surface on the side of the electrode terminal away from the bending structure. In the above structure, since the bending structure of the tab is directly welded with the electrode terminal to form the welding part, and the welding part forms the welding surface on the side of the electrode terminal away from the bending structure, not only the use of the adapter is reduced, but also the manufacturing process is reduced compared with the scheme using the adapter, the manufacturing convenience is improved, the occupation of the internal space of the shell by the adapter is further reduced, the volume of the electrode assembly is increased, and therefore the energy density of the battery monomer is improved. BRIEF DESCRIPTION OF DRAWINGS

[0031] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of the preferred embodiments and are not intended to limit the scope of the present application. Furthermore, the same reference numerals are used throughout the several views of the drawings to refer to same or like parts.

[0032] Figure 1 A schematic view of a vehicle provided by some embodiments of the present application;

[0033] Figure 2 A split structure schematic view of a battery device provided by some embodiments of the present application;

[0034] Figure 3 A structure schematic view of a battery monomer provided by some embodiments of the present application;

[0035] Figure 4 A structure schematic view of an electrode assembly provided by some embodiments of the present application;

[0036] Figure 5 A structure schematic view of a tab in a battery monomer provided by some embodiments of the present application;

[0037] Figure 6 A structure schematic view of an electrode terminal in a battery monomer provided by some embodiments of the present application;

[0038] Figure 7 A sectional view of an electrode terminal and a terminal cover plate in a battery monomer provided by some embodiments of the present application;

[0039] Figure 8A schematic view of a partial wall in a battery cell according to some embodiments of the present application;

[0040] Figure 9 A front view of a cover in a battery cell according to some embodiments of the present application;

[0041] Figure 10 A structural schematic view of a cover in a battery cell according to some embodiments of the present application from one perspective;

[0042] Figure 11 A structural schematic view of a cover in a battery cell according to some embodiments of the present application from another perspective.

[0043] In the drawings: 1, vehicle; 2, battery device; 3, controller; 4, motor; 5, box body; 5a, first box body part; 5b, second box body part; 5c, containing space; 7, battery cell; 8, electrode assembly; 81, electrode main body; 82, tab; 822, protruding structure; 823, bending structure; 821, tab layer; 8211, protruding part; 8212, bending part; 9, shell; 90, wall; 91, shell body; 92, cover; 921, through hole; 922, second recess; 93, containing cavity; 10, electrode terminal; 111, first recess; 112, welding surface; 113, step; 114, main body structure; 115, protruding structure; 1151, reinforcing structure; 116, welding part; 12, first insulation piece; 13, second insulation piece; 14, terminal cover plate; 15, pressure relief structure; 16, third insulation piece; 161, discharge channel; X, thickness direction; Y, 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] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in the embodiments of the present application should be understood as the usual meaning understood by the skilled person in the field to which the embodiments of the present application belong.

[0046] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "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 shown in the 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 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 present application.

[0047] In addition, the technical terms "first", "second" and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0048] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0049] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0050] At present, from the development of market situation, the application of battery device is more and more widely. The battery device is not only applied to the energy storage power supply system of water power, fire power, wind power and solar power station, but also widely applied to the battery monomer of energy storage container or energy storage cabinet. With the continuous expansion of the application field of battery device, the reliability of battery device is also continuously improved.

[0051] 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.

[0052] In some embodiments, the battery cell assembly is generally formed by arranging a plurality of battery cells.

[0053] The battery cell can be a secondary battery cell, which refers to a battery cell that can be activated by charging after discharging the battery cell.

[0054] The battery cell can be a lithium ion battery cell, a sodium ion battery cell, a sodium lithium ion battery cell, a lithium metal battery cell, a sodium metal battery cell, a lithium sulfur battery cell, a magnesium ion battery cell, a nickel hydrogen battery cell, a nickel cadmium battery cell, a lead-acid battery cell, etc.

[0055] The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of the battery cell, active ions (e.g., lithium ions) are inserted and extracted 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 the active ions to pass through.

[0056] The electrode assembly can be a wound structure, a stacked structure, or a hybrid structure of winding and stacking.

[0057] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell, or a battery cell of other shapes, and the prismatic battery cell includes a square cell, a blade cell, a multi-prismatic battery cell, such as a hexagonal prismatic battery cell, etc.

[0058] As an example, the battery cell assembly can be a battery module, which is formed by arranging and fixing a plurality of battery cells into an independent module. As an example, the battery module can be formed by bundling a plurality of battery cells with a cable tie.

[0059] In some embodiments, the battery apparatus can include one or more battery packs, and the battery pack can include one or more battery cell assemblies. As an example, the battery pack includes a box and one or more battery cell assemblies, and the battery cell assemblies are accommodated in the box, for example, by a fixing manner. As another example, the battery apparatus includes a plurality of battery packs, and the plurality of battery packs can be connected in series, in parallel, or in a mixed connection.

[0060] As an example, the box can include a first box and a second box. The first box and the second box are buckled so that the inside of the box forms a closed space to accommodate the battery monomer assembly. The closed here means covered or closed, which can be sealed or unsealed. The first box can be a top cover or a bottom plate.

[0061] As an example, the box can include a top cover, a frame and a bottom plate. The top cover and the bottom plate are connected with the frame respectively, so that the inside of the box forms a closed space to accommodate the battery monomer assembly.

[0062] In some embodiments, the box can be part of the chassis structure of the vehicle. For example, part of the box can be at least part of the floor of the vehicle, or part of the box can be at least part of the cross beam and the longitudinal beam of the vehicle.

[0063] In some embodiments, the battery device can be an energy storage device. The energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0064] At present, in the battery monomer, in order to facilitate the electrical connection between the electrode assembly and the electrode terminal, a switching piece is usually arranged in the space between the electrode terminal and part of the electrode assembly. The switching piece is welded with the tab of the electrode assembly and the electrode terminal. This not only makes the manufacturing process complex, but also occupies a large space inside the battery monomer, which is not conducive to the improvement of the energy density of the battery monomer.

[0065] In order to improve the energy density of the battery monomer, the embodiments of the present application provide a battery monomer, which comprises a shell, an electrode assembly and an electrode terminal. The shell comprises a wall portion. The electrode assembly is arranged in the shell. The electrode assembly is provided with a tab on the side facing the wall portion. The electrode terminal is arranged on the wall portion. The tab comprises a protruding structure and a bending structure connected with each other. The protruding structure extends to the wall portion along the thickness direction of the wall portion. The bending structure is bent relative to the thickness direction and abuts against the electrode terminal. The bending structure is welded with the electrode terminal to form a welding portion. The welding portion forms a welding surface on the side of the electrode terminal away from the bending structure. In the above structure, since the bending structure of the tab is directly welded with the electrode terminal to form the welding portion, and the welding portion forms the welding surface on the side of the electrode terminal away from the bending structure, the use of the switching piece is reduced, the manufacturing process is reduced compared with the scheme using the switching piece, the manufacturing convenience is improved, the occupation of the switching piece to the internal space of the shell is reduced, which is conducive to increasing the volume of the electrode assembly, thereby being conducive to improving the energy density of the battery monomer.

[0066] The battery monomer described in the embodiments of the present application is suitable for a battery device and a power utilization device using the battery device.

[0067] The electric device can be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy, and an electric tool, etc. The vehicle 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 electric automobile, or a range extended automobile, etc. The spacecraft includes an airplane, a rocket, a space shuttle, and a spacecraft, etc. The electric toy includes a fixed or mobile electric toy, such as a game machine, an electric automobile toy, an electric ship toy, and an electric airplane toy, etc. The electric tool includes a metal cutting electric tool, a grinding electric tool, an assembling electric tool, and a railway electric tool, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact electric drill, a concrete vibrator, and an electric planer, etc.

[0068] The following embodiments are described by taking a vehicle as an example for convenience of description.

[0069] Figure 1 A schematic diagram of the vehicle provided by some embodiments of the present application.

[0070] As shown in Figure 1 , the vehicle 1 is internally provided with a battery device 2, which can be arranged at the bottom, the head, or the tail of the vehicle 1. The battery device 2 can be used for power supply of the vehicle 1, for example, the battery device 2 can be used as an operating power supply of the vehicle 1.

[0071] The vehicle 1 can further include a controller 3 and a motor 4, and the controller 3 is used to control the battery device 2 to supply power to the motor 4, for example, to meet the power demand of the vehicle 1 during starting, navigation, and driving.

[0072] In some embodiments of the present application, the battery device 2 can not only be used as an operating power supply of the vehicle 1, but also be used as a driving power supply of the vehicle 1, to replace or partially replace fuel or natural gas to provide driving power for the vehicle 1.

[0073] Figure 2 A split structure schematic diagram of the battery device provided by some embodiments of the present application. As shown in Figure 2 , the battery device 2 includes a box body 5 and a battery monomer 7, and the battery monomer 7 is contained in the box body 5. The battery monomer 7 can be the smallest unit constituting a battery.

[0074] The box 5 is used to accommodate the battery cell 7, and the box 5 can be of various structures. In some embodiments, the box 5 can include a first box part 5a and a second box part 5b, the first box part 5a and the second box part 5b are mutually covered, and the first box part 5a and the second box part 5b jointly define an accommodation space 5c for accommodating the battery cell 7. The second box part 5b can be a hollow structure with one end open, and the first box part 5a is a plate-shaped structure, which covers the open side of the second box part 5b to form the box 5 with the accommodation space 5c; or the first box part 5a and the second box part 5b can both be hollow structures with one side open, and the open side of the first box part 5a covers the open side of the second box part 5b to form the box 5 with the accommodation space 5c. Of course, the first box part 5a and the second box part 5b can be of various shapes, such as a cylinder, a cuboid, etc.

[0075] To improve the sealing performance of the first box part 5a and the second box part 5b after being connected, a sealing member such as sealing glue, a sealing ring, etc. can be arranged between the first box part 5a and the second box part 5b.

[0076] Suppose that the first box part 5a covers the top of the second box part 5b, the first box part 5a can also be referred to as an upper box cover, and the second box part 5b can also be referred to as a lower box.

[0077] In the battery device 2, the battery cell 7 can be one or multiple. If the battery cell 7 is multiple, the multiple battery cells 7 can be connected in series, in parallel, or in a mixed manner, and the mixed manner means that the multiple battery cells 7 are connected in series and in parallel. The multiple battery cells 7 can be directly connected in series, in parallel, or in a mixed manner, and then the whole of the multiple battery cells 7 is accommodated in the box 5; of course, the multiple battery cells 7 can be first connected in series, in parallel, or in a mixed manner to form a battery module, and then the multiple battery modules are connected in series, in parallel, or in a mixed manner to form a whole, which is accommodated in the box 5.

[0078] Some embodiments of the present application provide a battery cell 7, which refers to Figure 3 includes a shell 9, an electrode assembly 8, and an electrode terminal 10, the shell 9 includes a wall part 90; the electrode assembly 8 is arranged in the shell 9, which refers to Figure 4 , the electrode assembly 8 is provided with a tab 82 on the side facing the wall part 90; the electrode terminal 10 is arranged on the wall part 90, which refers to Figure 5 , the tab 82 includes an extension structure 822 and a bending structure 823 connected to each other, the extension structure 822 extends to the wall part 90 along the thickness direction X of the wall part 90, and the bending structure 823 is bent relative to the thickness direction X and abuts against the electrode terminal 10, which refers to Figure 6The bending structure 823 is welded with the electrode terminal 10 to form a welding portion 116, and the welding portion 116 forms a welding surface 112 on the side of the electrode terminal 10 away from the bending structure 823.

[0079] The shell 9 can be a component in the battery monomer 7 for enclosing a sealed space, which is used to accommodate other components in the battery monomer 7. The wall portion 90 is a partial wall structure in the shell 9, which is used to enclose a sealed space in the shell 9.

[0080] The electrode assembly 8 is a component in the battery monomer 7 where electrochemical reactions occur. One or more electrode assemblies 8 can be contained in the shell 9. The side of the electrode assembly 8 facing the wall portion 90 is provided with a tab 82. The electrode assembly 8 includes an electrode body 81 and a tab 82, the tab 82 extends from the side of the electrode body 81 facing the wall portion 90, and the tab 82 is used to connect with the electrode terminal 10.

[0081] The electrode assembly 8 can include a positive electrode sheet, a negative electrode sheet, and a separator. The positive electrode sheet and the negative electrode sheet can be used as positive and negative electrodes, respectively. During the charging and discharging process of the battery monomer 7, active ions (such as lithium ions) are inserted and extracted between the positive and negative electrodes. The separator is arranged between the positive and negative electrode sheets, which is used to isolate the positive and negative electrode sheets, and can also allow active ions to pass through while preventing short circuiting between the positive and negative electrodes.

[0082] The electrode terminal 10 is a component arranged on the wall portion 90, which can be used to electrically connect with a power consumption device or a charging device outside the battery monomer 7, so that the battery monomer 7 can be charged and discharged. The electrode terminal 10 can include but is not limited to a cylindrical structure, an elliptical cylindrical structure, etc., which can be set according to actual conditions by those skilled in the art.

[0083] The protruding structure 822 and the bending structure 823 can be two different parts of the tab 82 connected to each other, wherein the protruding structure 822 extends along the thickness direction X of the wall portion 90 and extends from the electrode body 81 to the wall portion 90, and the bending structure 823 bends relative to the thickness direction X to approach the electrode terminal 10 so as to abut against the electrode terminal 10.

[0084] The welding portion 116 can refer to the structure formed by welding the bending structure 823 with the electrode terminal 10, which is the structure formed by solidification of the molten material after welding.

[0085] The welding surface 112 refers to the surface of the electrode terminal 10 on which welding is performed. By setting the side of the electrode terminal 10 away from the bent structure 823 as the welding surface 112, welding can be performed from the side of the electrode terminal 10 away from the bent structure 823, so that the material of the electrode terminal 10 can be mixed with the bent structure 823 after melting, and a welding portion 116 can be formed at the connection between the electrode terminal 10 and the bent structure 823 after the molten material solidifies, so that the side of the electrode terminal 10 away from the bent structure 823 is the welding surface 112 with the welding portion 116.

[0086] In the above structure, since the bent structure 823 of the tab 82 is directly welded with the electrode terminal 10 to form the welding portion 116, and the welding portion 116 forms the welding surface 112 on the side of the electrode terminal 10 away from the bent structure 823, not only the use of the adapter is reduced, but also the manufacturing process is reduced compared to the scheme using the adapter, the manufacturing convenience is improved, and the internal space of the shell 9 is further reduced. The adapter is occupied, which is beneficial to increase the volume of the electrode assembly 8, thereby being beneficial to improve the energy density of the battery monomer 7.

[0087] In some embodiments, the tab 82 includes a plurality of tab layers 821, the tab layers 821 include mutually connected protruding portions 8211 and bent portions 8212, the protruding portions 8211 of the plurality of tab layers 821 are stacked to form the protruding structure 822, and the bent portions 8212 of adjacent tab layers 821 are stacked in the thickness direction X to form the bent structure 823; in the bent structure 823, the number of layers of the bent portions 8212 stacked in the thickness direction X is D, and D≥3.

[0088] The tab layer 821 can be a portion of the electrode tab extending from the electrode body 81, and a plurality of tab layers 821 are connected to form the tab 82 to be connected to the electrode terminal 10. The protruding portion 8211 and the bent portion 8212 can be two different portions of the tab layer 821 connected to each other, wherein the protruding portion 8211 extends from the electrode body 81 along the thickness direction X, and the bent portion 8212 is bent relative to the thickness direction X to approach the electrode terminal 10.

[0089] The bent portions 8212 of adjacent tab layers 821 are stacked in the thickness direction X to form the bent structure 823, which can mean that the bent portions 8212 of adjacent tab layers 821 are stacked along the thickness direction X, so that adjacent tab layers 821 are connected and formed by the stacking of the bent portions 8212 to form the bent structure 823 for connecting to the electrode terminal 10, facilitating the connection of the overall tab 82 formed by a plurality of tab layers 821 to the electrode terminal 10.

[0090] By setting the range of the number of layers D of the bending portion 8212 in the bending structure 823 stacked in the thickness direction X to D≥3, the bending portion 8212 in the bending structure 823 has a sufficient number of layers, so that the tab 82 has sufficient structural strength and thickness, so that the tab 82 is not easily welded through when the electrode terminal 10 is welded with the tab 82, and the welding quality of the electrode terminal 10 and the tab 82 is improved.

[0091] In some embodiments, the projection of the electrode terminal 10 falls within the projection range of the bending structure 823 along the thickness direction X.

[0092] By making the projection of the electrode terminal 10 along the thickness direction X fall within the projection range of the bending structure 823 along the thickness direction X, the electrode terminal 10 can be connected to the tab 82 by connecting with the bending structure 823. Since the bending structure 823 is bent relative to the thickness direction X, the electrode terminal 10 is connected to the tab 82 by connecting with the bending structure 823, which is advantageous for increasing the connection area of the electrode terminal 10 and the tab 82, and for reducing the internal resistance of the battery cell 7.

[0093] In some embodiments, the projection of the bending structure 823 along the thickness direction X exceeds the projection range of the electrode terminal 10.

[0094] By making the projection of the bending structure 823 along the thickness direction X exceed the range of the projection of the electrode terminal 10 along the thickness direction X, the bending structure 823 has a larger area to accommodate the relative position fluctuations of the tab 82 and the electrode terminal 10 due to manufacturing and assembly tolerances.

[0095] In some embodiments, the size of the projection of the bending structure 823 along the thickness direction X in the first direction Y is B, and the size of the projection of the electrode terminal 10 along the thickness direction X in the first direction Y is C, 5%≤(B-C) / C≤20%, and the first direction Y is perpendicular to the thickness direction X.

[0096] The first direction Y can be a direction perpendicular to the thickness direction X, which is the extension direction of the bending structure 823 after bending, and is parallel to the surface of the electrode terminal 10 facing the tab 82.

[0097] By setting the size of the projection of the bending structure 823 along the thickness direction X on the first direction Y as B, the size of the projection of the electrode terminal 10 along the thickness direction X on the first direction Y as C, and the relationship between B and C as 5%≤(B-C) / C≤20%, the projection of the bending structure 823 along the thickness direction X on the first direction Y can exceed the appropriate size of the projection of the electrode terminal 10 along the thickness direction X, not only making the bending structure 823 have sufficient excess size to adapt to the relative position fluctuation of the tab 82 and the electrode terminal 10 caused by manufacturing and assembly tolerances, but also making the bending structure 823 not cause the waste of the size of the tab 82 in the first direction Y due to excessive size.

[0098] In some embodiments, the size of the extension structure 822 extending along the thickness direction X is E, and 1.5mm≤E≤8mm.

[0099] By setting the range of the size E of the extension structure 822 extending along the thickness direction X as 1.5mm≤E≤8mm, the size of the tab 82 in the thickness direction X is appropriate, not only making the size of the tab 82 in the thickness direction X not too large to occupy more space, but also making the tab 82 be able to extend from the electrode body 81 to a sufficient size to connect with the electrode terminal 10.

[0100] In some embodiments, 2mm≤E≤6mm.

[0101] By setting the range of the size E of the extension structure 822 extending along the thickness direction X as 2mm≤E≤6mm, for example, the size of the extension structure 822 extending along the thickness direction X can be 2mm, 4mm, 5mm or 6mm, not only making the size of the tab 82 in the thickness direction X not too large to occupy more space, but also making the tab 82 be able to extend from the electrode body 81 to a sufficient size to connect with the electrode terminal 10.

[0102] In some embodiments, the ratio of the maximum number of layers of the bending part 8212 laminated in the thickness direction X to the total number of layers of the tab layer 821 is A, and 15%≤A≤30%.

[0103] By setting the range of the ratio A of the maximum number of layers of the bending part 8212 laminated in the thickness direction X to the total number of layers of the tab layer 821 as 15%≤A≤30%, not only making the maximum number of layers of the bending part 8212 in the thickness direction X sufficient for the bending structure 823 of the tab 82 to have a certain structural strength and thickness to reduce the possibility of welding through, but also making the maximum number of layers of the bending part 8212 in the thickness direction X not too much to make the bending structure 823 occupy too much space in the thickness direction X.

[0104] In some embodiments, the bending part 8212 is configured in a zigzag shape.

[0105] By configuring the bending part 8212 as a zigzag shape, the bending part 8212 can be more easily bent relative to the extending part 8211, which is conducive to reducing the difficulty of bending the multi-layer tab layer 821 to form the bending structure 823.

[0106] In other embodiments, the bending part 8212 can also be configured as a trapezoidal shape, a rectangular shape, or other shapes, and those skilled in the art can set the shape of the bending part 8212 according to actual conditions.

[0107] In some embodiments, referring to Figure 7 The battery cell 7 further includes a terminal cover plate 14 connected to the electrode terminal 10, at least part of the terminal cover plate 14 is located on the side of the electrode terminal 10 away from the tab 82 and covers the welding surface 112.

[0108] The terminal cover plate 14 can be a component for covering the welding part 116 on the welding surface 112, which not only can reduce the possibility of the welding part 116 contacting rainwater from the outside, thereby reducing the possibility of the welding part 116 being corroded, but also can serve as a component for contacting the charging and discharging device, thereby reducing the wear of the electrode terminal 10.

[0109] The terminal cover plate 14 is connected to the electrode terminal 10, which can be that the terminal cover plate 14 is connected to the electrode terminal 10 by welding, or the terminal cover plate 14 is connected to the electrode terminal 10 by conductive glue, so that current can flow between the terminal cover plate 14 and the electrode terminal 10.

[0110] In some embodiments, the terminal cover plate 14 is welded to the electrode terminal 10.

[0111] Since welding can cause the material of the terminal cover plate 14 to be fused with the material of the electrode terminal 10, it is conducive to improving the connection strength between the terminal cover plate 14 and the electrode terminal 10, so that the terminal cover plate 14 can withstand greater force.

[0112] In some embodiments, the side of the electrode terminal 10 away from the tab 82 is provided with a first recess 111, and the bottom wall of the first recess 111 is welded to the bending structure 823.

[0113] The first recess 111 can be a structure formed by recessing inwardly from the surface of the electrode terminal 10 away from the tab 82. By providing the first recess 111 on the side of the electrode terminal 10 away from the tab 82, not only the weight of the electrode terminal 10 is reduced, but also the thickness of the area of the electrode terminal 10 corresponding to the first recess 111 is thinned, which is beneficial for the material on the bottom wall of the first recess 111 to be more easily melted during welding, thereby saving energy consumption during welding. By welding the bottom wall of the first recess 111 to the bending structure 823, the area of the electrode terminal 10 with a relatively thin thickness is welded together with the bending structure 823, which is beneficial for reducing the difficulty of welding and reducing energy consumption.

[0114] In some embodiments, at least part of the terminal cover plate 14 is located in the first recess 111.

[0115] At least part of the terminal cover plate 14 being located in the first recess 111 can mean that part of the terminal cover plate 14 is located in the first recess 111, or it can also mean that the entire terminal cover plate 14 is located in the first recess 111.

[0116] By locating at least part of the terminal cover plate 14 in the first recess 111, at least part of the terminal cover plate 14 is inserted into the first recess 111, which is beneficial for improving the connection firmness of the terminal cover plate 14 and the first recess 111.

[0117] In some embodiments, a step 113 protruding towards the first recess 111 is provided on the side wall of the first recess 111, and the terminal cover plate 14 located in the first recess 111 abuts against the step 113.

[0118] The step 113 can be a structure for abutting against the terminal cover plate 14, which protrudes inwardly into the first recess 111 on the side wall of the first recess 111, so that the terminal cover plate 14 can come into contact with the step 113 in the first recess 111 when the terminal cover plate 14 extends into the first recess 111. By abutting the terminal cover plate 14 located in the first recess 111 against the step 113, the terminal cover plate 14 can be positioned by abutting against the step 113 in the first recess 111 during insertion into the first recess 111.

[0119] In some embodiments, the wall portion 90 is provided with a through hole 921 penetrating in the thickness direction X, the electrode terminal 10 comprises a main body structure 114 and an extending structure 115 connected in the thickness direction X, in the radial direction of the through hole 921, the main body structure 114 protrudes from the extending structure 115, the main body structure 114 covers the through hole 921 and is located on the side of the wall portion 90 away from the electrode assembly 8, and the extending structure 115 passes through the through hole 921, part of the extending structure 115 is located on the side of the wall portion 90 facing the electrode assembly 8 and abuts against the bending structure 823.

[0120] The through hole 921 can be a hole-like structure provided on the wall portion 90 and penetrating the wall portion 90 along the thickness direction X. The main body structure 114 and the protruding structure 115 can be structural parts in the electrode terminal 10, which are arranged along the thickness direction X and connected.

[0121] In the radial direction of the through hole 921, the main body structure 114 protrudes from the protruding structure 115, which can mean that, in the axial direction of the through hole 921, the projection of the main body structure 114 covers the projection of the protruding structure 115, so that the main body structure 114 can cover the through hole 921 from the side of the wall portion 90 away from the electrode assembly 8 when the protruding structure 115 protrudes into the through hole 921.

[0122] By covering the through hole 921 with the main body structure 114 and locating the main body structure 114 on the side of the wall portion 90 away from the electrode assembly 8, the main body structure 114 can be covered and sealed from the outside. By making the protruding structure 115 pass through the through hole 921 and locating part of the protruding structure 115 on the side of the wall portion 90 facing the electrode assembly 8 and abutting against the bent structure 823, part of the protruding structure 115 protrudes to the side of the wall portion 90 facing the electrode assembly 8, which can facilitate abutting against the bent structure 823 and connecting the bent structure 823 with the protruding structure 115.

[0123] In some embodiments, the battery cell 7 further comprises a first insulating member 12 connected to the wall portion 90, which isolates the wall portion 90 from the electrode terminal 10.

[0124] The first insulating member 12 can be a member with insulating properties. The first insulating member 12 isolates the wall portion 90 from the electrode terminal 10, which can mean that at least part of the first insulating member 12 is arranged in the gap between the electrode terminal 10 and the wall portion 90.

[0125] By connecting the first insulating member 12 to the wall portion 90 at the through hole 921, not only can the first insulating member 12 seal the gap between the electrode terminal 10 and the wall portion 90, but also isolate the wall portion 90 from the electrode terminal 10, so that the electrode terminal 10 and the wall portion 90 are insulated, so that the wall portion 90 is not electrified, so that the wall portion 90 is less likely to be electrically connected to external devices.

[0126] In some embodiments, with reference to Figure 8 , the surface of the wall portion 90 away from the electrode assembly 8 is recessed inward to form a second recess 922, the second recess 922 is communicated with the through hole 921, the outer circumferential surface of the protruding structure 115 is provided with a reinforcing structure 1151, the reinforcing structure 1151 is located in the second recess 922 and is spaced apart from the main body structure 114 in the thickness direction X, and the first insulating member 12 covers the reinforcing structure 1151.

[0127] The second recess 922 can be a structure formed by the surface of the wall portion 90 being recessed inward away from the electrode assembly 8. By communicating the second recess 922 with the through hole 921, the reinforcing structure 1151 protruding on the extension structure 115 can be accommodated in the second recess 922.

[0128] The reinforcing structure 1151 can be a structure for improving the sealing performance between the electrode terminal 10 and the inner wall of the through hole 921. By protruding the reinforcing structure 1151 on the outer peripheral surface of the extension structure 115, the reinforcing structure 1151 extends into the second recess 922 and extends into the first insulating member 12, so that the first insulating member 12 covers the reinforcing structure 1151. Since the reinforcing structure 1151 protruding on the outer peripheral surface of the extension structure 115 increases the contact area between the electrode terminal 10 and the first insulating member 12, it is beneficial to improve the sealing effect of the first insulating member 12 between the electrode terminal 10 and the inner wall of the through hole 921.

[0129] In some embodiments, a plurality of reinforcing structures 1151 are provided, and the plurality of reinforcing structures 1151 are arranged at intervals along the circumference of the extension structure 115.

[0130] By providing a plurality of reinforcing structures 1151, it is beneficial to improve the ability of the reinforcing structure 1151 to increase the contact area between the electrode terminal 10 and the first insulating member 12, and to improve the sealing effect of the first insulating member 12 between the electrode terminal 10 and the inner wall of the through hole 921.

[0131] The plurality of reinforcing structures 1151 arranged at intervals along the circumference of the extension structure 115 can mean that the plurality of reinforcing structures 1151 are arranged at equal intervals along the circumference of the extension structure 115, so that the first insulating member 12 can uniformly improve the sealing effect between the electrode terminal 10 and the inner wall of the through hole 921 under the action of the plurality of reinforcing structures 1151.

[0132] In some embodiments, a plurality of electrode assemblies 8 are provided, and the plurality of electrode assemblies 8 are arranged along a second direction, the lugs 82 of the plurality of electrode assemblies 8 are arranged along the second direction, the electrode terminal 10 is welded with the bent structure 823 of the plurality of lugs 82, and the second direction is perpendicular to the thickness direction X.

[0133] The first direction Y can be a direction perpendicular to the thickness direction X, which is the extension direction after the bent structure 823 is bent, and is parallel to the surface of the electrode terminal 10 facing the lug 82.

[0134] By arranging multiple electrode assemblies 8 along the first direction Y, multiple electrode assemblies 8 can be disposed in the housing 9, which is beneficial to increasing the capacity of the battery cell 7. By arranging the tabs 82 of the multiple electrode assemblies 8 along the second direction, the electrode terminals 10 can be easily connected to the tabs 82 of the multiple electrode assemblies 8. By welding the electrode terminals 10 to the bent structures 823 of the multiple tabs 82, the multiple electrode assemblies 8 can be stably electrically connected to the electrode terminals 10.

[0135] In some embodiments, the projection of the tab 82 along the thickness direction X is rectangular.

[0136] By setting the projection of the tab 82 along the thickness direction X as a rectangle, the electrode assembly 8 in the battery cell 7 can be a stacked structure. Each electrode layer in the stacked electrode assembly 8 extends out a tab layer 821.

[0137] For example, the projection of the tab 82 along the thickness direction X can also be arc-shaped, and the electrode assembly 8 in the battery cell 7 can be a wound structure. Each turn of the electrode assembly 8 in the wound structure has a tab layer 821 extending out.

[0138] In some embodiments, the housing 9 is configured as a cuboid structure.

[0139] By configuring the outer casing 9 into a cuboid structure, the battery cell 7 is a cuboid-shaped battery cell 7.

[0140] In some embodiments, the housing 9 includes a housing 91 and a cover 92, the housing 91 forming a cavity 93 with an opening, the electrode assembly 8 being located in the cavity 93, and the cover 92 covering the opening, the cover 92 being configured as the wall portion 90.

[0141] The housing 91 and the cover 92 are two interconnected parts of the outer casing 9. The housing 91 forms a cavity 93 with one open end, allowing components such as the electrode assembly 8 to be easily inserted into the cavity 93 through the opening. The cover 92 is a part used to seal the opening, and its sealing cover fits onto the housing 91 to form a sealed space in the cavity 93. By configuring the cover 92 as a wall portion 90, the electrode terminal 10 is disposed on the cover 92. Since the cover 92 has a smaller size than the housing 91, the electrode terminal 10 can be disposed on the cover 92 more conveniently.

[0142] For example, the cover 92 and the electrode terminal 10 can be provided as inserts in the injection mold, and the first insulating member 12 is formed by filling the gap between the cover 92 and the electrode terminal 10 in the injection mold. The first insulating member 12 connects the cover 92 and the electrode terminal 10 and seals the gap between the cover 92 and the electrode terminal 10.

[0143] In some embodiments, referring to Figure 9 The battery cell 7 further comprises a second insulation member 13 disposed on the surface of the cover 92 facing the cavity 93, and part of the electrode terminal 10 protrudes from the second insulation member 13 along the thickness direction X.

[0144] The second insulation member 13 can be a component disposed on the surface of the cover 92 facing the cavity 93 for insulating and isolating the cover 92 from the inside of the battery cell 7. For example, the second insulation member 13 can also be formed on the surface of the cover 92 facing the cavity 93 by injection molding. When the cover 92 and the electrode terminal 10 are disposed as inserts in the injection mold, the material of the second insulation member 13 is injected on the surface of the cover 92 facing the cavity 93 by the injection mold to form the second insulation member 13.

[0145] By making part of the electrode terminal 10 protrude from the second insulation member 13 along the thickness direction X, the tab 82 can be conveniently abutted with the part of the electrode terminal 10 protruding from the second insulation member 13 along the thickness direction X, which is conducive to the tab 82 being conveniently connected with the electrode terminal 10.

[0146] In some embodiments, referring to Figure 10 The wall portion 90 is provided with a pressure relief structure 15 for communicating the inside of the shell 9 with the outside when the battery cell 7 experiences thermal runaway.

[0147] For example, the pressure relief structure 15 can be formed by a notch formed on the wall portion 90 for thickness reduction. When the pressure in the shell 9 is greater than a preset pressure, the wall portion 90 is broken at the notch to achieve pressure relief. This form of pressure relief structure 15 can be integrally formed with the wall portion 90 by a stamping process.

[0148] In some embodiments, referring to Figure 11 The battery cell 7 further comprises a third insulation member 16 connected with the second insulation member 13, the third insulation member 16 is disposed on the side of the pressure relief structure 15 facing the electrode assembly 8, and the third insulation member 16 is provided with a discharge channel 161, the discharge channel 161 penetrates the third insulation member 16 along the thickness direction X.

[0149] For example, the third insulation member 16 can be provided in a mesh structure with a plurality of discharge channels 161, so that the cavity 93 in the shell 9 can communicate with the pressure relief structure 15 through the discharge channels 161 in the third insulation member 16.

[0150] In some embodiments, the third insulating member 16 protrudes towards the cavity 93 relative to the second insulating member 13 along the thickness direction X, and the electrode terminal 10 protrudes from or is flush with the third insulating member 16.

[0151] By protruding the third insulating member 16 towards the cavity 93 relative to the second insulating member 13 along the thickness direction X, the third insulating member 16 can resist the electrode assembly 8, a gap can be formed between the second insulating member 13 and the electrode assembly 8, and the gas generated by thermal runaway in the shell 9 can smoothly reach the discharge passage 161 through the gap.

[0152] Some embodiments of the present application also provide a battery device 2 comprising the battery cell 7 provided in the above technical solutions.

[0153] Some embodiments of the present application also provide a power utilization device comprising the battery device 2 provided in the above technical solutions, and the battery device 2 is used to provide electric energy.

[0154] Some embodiments of the present application provide a battery cell 7 comprising a shell 9, an electrode assembly 8, and an electrode terminal 10. The shell 9 comprises a shell body 91 and a cover 92. The shell body 91 forms a cavity 93 with an opening. The electrode assembly 8 is located in the cavity 93. The cover 92 covers the opening. The electrode assembly 8 is arranged in the cavity 93. The electrode assembly 8 is provided with a tab 82 on a side facing the cover 92. The tab 82 is provided with an extending structure 822 extending towards the wall 90 along a thickness direction X of the wall 90. The tab 82 is provided with a bending structure 823 bent relative to the thickness direction X and welded with the electrode terminal 10 to form a welding portion 116. The welding portion 116 forms a welding surface 112 on a side of the electrode terminal 10 away from the bending structure 823. The electrode terminal 10 is connected with the terminal cover plate 14. A main body structure 114 of the electrode terminal 10 covers a through hole 921 in the cover 92 from a side of the cover 92 away from the electrode assembly 8. An extending structure 115 extends through the through hole 921 and extends into the cavity 93 to abut against the tab 82. A first recess 111 is arranged on a side of the electrode terminal 10 away from the tab 82. A bottom wall of the first recess 111 is welded with the tab 82 to form the welding portion 116. The welding portion 116 is located on a side of the bottom wall of the first recess 111 away from the tab 82.

[0155] In the above structure, since the bent structure 823 of the tab 82 is directly welded with the electrode terminal 10 to form the welding portion 116, and the welding portion 116 forms the welding surface 112 on the side of the electrode terminal 10 away from the bent structure 823, not only the use of the adapter is reduced, but also the manufacturing process is reduced compared with the scheme using the adapter, the manufacturing convenience is improved, the internal space of the shell 9 is further reduced, which is beneficial to increase the volume of the electrode assembly 8, thereby being beneficial to improve the energy density of the battery monomer 7.

[0156] In the above structure, since the tab 82 is abutted and welded with the electrode terminal 10 arranged on the wall portion 90, and the welding portion 116 is located on the welding surface 112 on the side of the electrode terminal 10 away from the tab 82, the tab 82 and the electrode terminal 10 can be directly welded on the side of the electrode terminal 10 away from the tab 82, which reduces the use of the adapter, not only reduces the manufacturing process, but also improves the manufacturing convenience, and reduces the space occupation, which is beneficial to improve the energy density of the battery monomer 7.

[0157] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; 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 be covered in the scope of the claims and the specification of the present application. Especially, 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 in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized by, The battery monomer comprises: a shell comprising a wall portion; an electrode assembly arranged in the shell, the electrode assembly being provided with a tab on a side facing the wall portion; an electrode terminal arranged on the wall portion, the tab comprising an extension structure and a bending structure connected to each other, the extension structure extending along a thickness direction of the wall portion, the bending structure being bent relative to the thickness direction and abutting against the electrode terminal, the bending structure being welded with the electrode terminal to form a welding portion, the welding portion forming a welding surface on a side of the electrode terminal away from the bending structure.

2. The battery cell of claim 1, wherein, The tab comprises a plurality of tab layers, the tab layers comprising an extension portion and a bending portion connected to each other, the extension portions of the plurality of tab layers being stacked to form the extension structure, the bending portions of adjacent tab layers being stacked in the thickness direction to form the bending structure; in the bending structure, the number of layers of the bending portions stacked in the thickness direction is D, and D≥3.

3. The battery cell according to claim 1 or 2, characterized in that, Along the thickness direction, a projection of the electrode terminal falls within a projection range of the bending structure.

4. The battery cell of claim 1, wherein, Along the thickness direction, a projection of the bending structure exceeds the projection range of the electrode terminal.

5. The battery cell of claim 1, wherein, A size of the projection of the bending structure along the thickness direction in a first direction is B, a size of the projection of the electrode terminal along the thickness direction in the first direction is C, and 5%≤(B-C) / C≤20%, the first direction being perpendicular to the thickness direction.

6. The battery cell of claim 1, wherein, A size of the extension structure extending along the thickness direction is E, and 1.5mm≤E≤8mm.

7. The battery cell of claim 6, wherein, 2mm≤E≤6mm.

8. The battery cell of claim 2, wherein, A ratio of the maximum number of layers of the bending portions stacked in the thickness direction to the total number of layers of the tab layers is A, and 15%≤A≤30%.

9. The battery cell according to claim 2 or 8, characterized in that, The bending portion is configured in a zigzag shape.

10. The battery cell of claim 1, wherein, The battery monomer further comprises a terminal cover plate connected to the electrode terminal, at least part of the terminal cover plate being located on a side of the electrode terminal away from the tab and covering the welding surface.

11. The battery cell of claim 10, wherein, The electrode terminal is provided with a first recess on a side away from the tab, a bottom wall of the first recess being welded to the bending structure.

12. The battery cell of claim 11, wherein, At least part of the terminal cover plate is located in the first recess.

13. The battery cell of claim 12, wherein, A step protruding into the first recess is arranged on a side wall of the first recess, and the terminal cover plate located in the first recess abuts against the step.

14. The battery cell of claim 1, wherein, The wall portion is provided with a through hole penetrating along the thickness direction, the electrode terminal comprising a main body structure and an extension structure connected along the thickness direction, along a radial direction of the through hole, the main body structure protruding from the extension structure, the main body structure covering the through hole and being located on a side of the wall portion away from the electrode assembly, and the extension structure penetrating through the through hole, part of the extension structure being located on a side of the wall portion facing the electrode assembly and abutting against the bending structure.

15. The battery cell of claim 14, wherein, The battery monomer further comprises a first insulating member connected to the wall portion, the first insulating member isolating the wall portion from the electrode terminal.

16. The battery cell of claim 15, wherein, A surface of the wall portion, which faces away from the electrode assembly, is recessed inward to form a second recess, the second recess being communicated with the through hole, an outer peripheral surface of the protruding structure is provided with a reinforcing structure, the reinforcing structure is located in the second recess and is spaced apart from the main structure in the thickness direction, and the first insulating member covers the reinforcing structure.

17. The battery cell of claim 16, wherein, A plurality of reinforcing structures are provided, and the plurality of reinforcing structures are arranged in a circumferential direction of the protruding structure.

18. The battery cell of claim 1, wherein, A plurality of electrode assemblies are provided, the plurality of electrode assemblies are arranged in a first direction, the lugs of the plurality of electrode assemblies are arranged in the first direction, the electrode terminal is welded to the bent structure of the plurality of lugs, and the first direction is perpendicular to the thickness direction.

19. The battery cell of claim 1, wherein, In the thickness direction, a projection of the lug is rectangular.

20. The battery cell of claim 1, wherein, The shell is configured in a cuboid structure.

21. The battery cell of claim 1, wherein, The shell includes a shell body and a cover body, the shell body forms a cavity with an opening, the electrode assembly is located in the cavity, and the cover body covers the opening, the cover body is configured as the wall portion.

22. A battery device, characterized by The battery cell includes the battery cell as claimed in any one of claims 1-21.

23. An electrical device, comprising: The battery device includes the battery device as claimed in claim 22, and the battery device is used to provide electric energy.

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