Battery cell, battery device, and electric device

Abstract

The application provides a battery monomer, a battery device and a power utilization device. The electrode assembly in a winding structure is accommodated in a shell. The electrode assembly includes an electrode body and a tab. The electrode body includes a plurality of laminated pole pieces. An adapter is arranged between a wall portion and the electrode body and connected with an electrode terminal. An extension portion in the adapter extends from a main body portion in a first direction. The first direction, a second direction and a laminating direction of the plurality of pole pieces are perpendicular to each other. A plurality of tab layers are welded with the adapter to form a welding portion. The welding portion includes a first portion and a second portion arranged in the first direction. When the plurality of laminated tab layers are misaligned in the first direction, the welding portion formed by the first portion and the second portion can still cover the plurality of laminated tab layers. Each tab layer can still be connected with the adapter through the welding portion. The connection performance of the tab and the adapter is improved, and the reliability of the battery monomer is improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell, a battery device, and an electrical device. Background Technology

[0002] Battery devices have advantages such as high specific energy and high power density, and are widely used in electronic devices and transportation vehicles, such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships and power tools.

[0003] As the application scope of battery devices continues to expand, the requirements for their reliability are also increasing. How to improve the reliability of battery devices has always been a key focus for those skilled in the art. Utility Model Content

[0004] In view of the above problems, this application provides a battery cell, a battery device, and an electrical device, wherein the battery cell has good reliability.

[0005] In a first aspect, some embodiments of this application provide a battery cell, which includes a casing, electrode terminals, an electrode assembly, and an adapter. The casing includes a wall portion, the electrode terminals are disposed in the wall portion, the electrode assembly is housed in the casing, the electrode assembly includes an electrode body and tabs, the electrode body includes a plurality of stacked electrode sheets, and tab layers extend from the ends of the electrode sheets in a second direction, the second direction being perpendicular to the stacking direction of the plurality of electrode sheets, the plurality of tab layers being stacked to form tabs; the adapter is disposed between the wall portion and the electrode body and connected to the electrode terminals, the adapter includes a main body portion and an extension portion, the extension portion extending from the main body portion along a first direction, the first direction, the second direction, and the stacking direction of the plurality of electrode sheets being perpendicular to each other, the plurality of tab layers being welded to the adapter to form a welded portion, the welded portion including a first part and a second part, the first part being located in the main body portion, and at least a portion of the second part being located in the extension portion.

[0006] In the above structure, since the adapter includes an extension extending from the main body in a first direction, at least a second part of the welded portion formed by welding multiple tab layers to the adapter is disposed on the extension. This allows multiple stacked tab layers to still be connected by the welded portion composed of the first and second parts even when they are misaligned in the first direction. This ensures that each tab layer can still be connected to the adapter through the welded portion even when the multiple tab layers are misaligned in the first direction, enabling the tabs to be reliably connected to the adapter. This improves the connection performance between the tabs and the adapter and helps to improve the reliability of the battery cell.

[0007] According to some embodiments of this application, the battery cell has a second direction pointing from the electrode body to the wall. The wall has an injection hole that penetrates the wall along the second direction, and the injection hole and the electrode terminals are arranged along a first direction. A flow guiding structure is connected to the wall, and the flow guiding structure is located on one side of the injection hole in the second direction. The adapter has a clearance hole that penetrates the second direction, and at least a portion of the flow guiding structure extends into the clearance hole. By allowing at least a portion of the flow guiding structure to extend into the clearance hole, the adapter can avoid the flow guiding structure through the clearance hole, allowing the adapter to extend to a larger area without interfering with the flow guiding structure. This facilitates the adapter to have a larger area for welding with multiple tab layers, and helps to improve the current-carrying capacity at the connection between the adapter and the tab.

[0008] According to some embodiments of the present application, the battery cell has an extension portion disposed on one side of the clearance hole in the stacking direction of multiple electrode sheets, so that the welding portion can make full use of the space on the adapter through the second part on the extension portion, which is beneficial to improving the utilization rate of the adapter and thus reducing the area of ​​the adapter.

[0009] According to some embodiments of the present application, a clearance hole is provided on the main body, and the clearance hole communicates with the end face of the extension portion of the main body. By providing the clearance hole on the adapter portion, the arrangement of the clearance hole is less likely to affect the connection between the connector portion and the electrode terminal, which helps to improve the firmness of the connection between the adapter and the motor terminal.

[0010] According to some embodiments of this application, the battery cell has two extensions, which are disposed opposite to each other on both sides of the clearance hole along the stacking direction of the plurality of electrode sheets, so that the gap between the two extensions can serve as a clearance hole.

[0011] According to some embodiments of the present application, in the stacking direction of multiple electrode sheets, the maximum size of the first part is larger than the maximum size of the second part, so that a larger first part can be provided on the main body, which is beneficial to increase the area of ​​the welding part and improve the reliability of the connection between the electrode tab and the adapter.

[0012] According to some embodiments of the present application, the size of the second part of the battery cell is set to L along the first direction, where 10mm≤L≤20mm, so that the second part can not only increase the size of the welding part in the first direction, but also does not occupy too much space inside the battery cell.

[0013] According to some embodiments of the present application, in the tab region welded to the welding part, the number of tab layers is set to D, where D≥3, so that the tab layer in the tab region welded to the welding part has a sufficient number of layers, so that the tab has sufficient structural strength and thickness, so that the tab is not easily welded through when the adapter is welded to the tab, which is beneficial to improving the welding quality of the adapter and the tab.

[0014] According to some embodiments of the present application, the area of ​​the tab layer is set to A, and the area of ​​the tab layer connected to the welding part is set to B, 0.5≤B / A≤0.8. This not only ensures that each tab layer has sufficient area to connect with the welding part 10, which is beneficial to improving the connection strength and current carrying capacity between the tab and the adapter, but also reduces the process difficulty caused by excessively increasing the area of ​​the welding part.

[0015] According to some embodiments of this application, the battery cell has a second part connected to the first part, which enables the welded part to form an integral structure. This not only improves the overall structural strength of the welded part, but also enables the welded part with the first part and the second part to be formed by a single welding head, which improves the welding efficiency of the adapter and the tab.

[0016] According to some embodiments of this application, the battery cell includes an interconnected protruding structure and a bent structure. The protruding structure extends from the electrode body along a second direction, and the bent structure is bent relative to the second direction and abuts against the surface of the adapter facing the electrode body. By bending relative to the second direction, the bent structure increases the area abutting against the adapter, thereby enhancing the current-carrying capacity between the adapter and the electrode terminal.

[0017] According to some embodiments of this application, the battery cell has a pressure relief mechanism on its wall, and the pressure relief mechanism and the electrode terminals are arranged along a first direction; in a second direction, the projection of the pressure relief mechanism is separate from the projection of the adapter. By ensuring that the orthographic projection of the pressure relief mechanism in the second direction does not overlap with the orthographic projection of the adapter in the second direction, the adapter is less likely to affect the operation of the pressure relief mechanism, thus providing the pressure relief mechanism with sufficient discharge area and improving the reliability of the battery cell.

[0018] According to some embodiments of the present application, the battery cell has an electrode assembly configured as a wound structure. The electrode body includes two bent regions disposed opposite each other along a first direction and a straight region connected between the two bent regions. A tab is connected to the end of the straight region in a second direction. The tab is connected to the end of the straight region in the second direction such that the tab extends from the end of the electrode body in the second direction.

[0019] According to some embodiments of this application, the adapter further includes a connecting portion connected to the side of the main body away from the extension portion along a first direction, and the connecting portion is connected to the electrode terminal.

[0020] According to some embodiments of this application, the battery cell further includes a first insulating member connected to the wall portion. At least a portion of the first insulating member is disposed between the wall portion and the adapter. The electrode terminals pass through the first insulating member and are connected to the connecting portion, so that the electrode terminals can pass through the first insulating member used for insulation and isolation and be connected to the adapter.

[0021] According to some embodiments of this application, the battery cell has a second direction pointing from the electrode body to the wall portion. The wall portion is provided with a liquid injection hole, which penetrates the wall portion along the second direction. The liquid injection hole and the electrode terminal are arranged along the first direction. The adapter is provided with a clearance hole penetrating along the second direction. The first insulating member is provided with a flow guiding structure, which is disposed opposite to the liquid injection hole along the second direction. At least a portion of the flow guiding structure extends into the clearance hole, thereby reducing the possibility of interference between the flow guiding structure and the adapter.

[0022] According to some embodiments of the present application, in a battery cell, in a second direction, a portion of the electrode terminals protrudes from the first insulating member. The adapter further includes a bent portion connecting the connecting portion and the main body portion. The bent portion bends towards the connecting portion relative to the main body portion. The connecting portion is closer to the electrode body than the main body portion, and the connecting portion is located on the side of the electrode terminal closer to the electrode body. By making the connecting portion closer to the electrode body than the adapter portion, the connecting portion can be located on the side of the electrode terminal closer to the electrode body, facilitating the connection of the connecting portion to the surface of the electrode terminal closer to the electrode body.

[0023] Secondly, some embodiments of this application also provide a battery device, which includes the battery cell provided by any of the above-described technical solutions.

[0024] Thirdly, some embodiments of this application also provide an electrical device, which includes the battery device provided by the above-described technical solution, and the battery device is used to provide electrical energy.

[0025] The technical solutions provided by the embodiments of this disclosure bring at least the following beneficial effects: An embodiment of this application provides a battery cell, which includes a casing, electrode terminals, an electrode assembly, and an adapter. The casing includes a wall portion, the electrode terminals are disposed in the wall portion, the electrode assembly is housed in the casing, and the electrode assembly includes an electrode body and tabs. The electrode body includes multiple stacked electrode sheets, and tab layers extend from the ends of the electrode sheets in a second direction, which is perpendicular to the stacking direction of the multiple electrode sheets. The multiple tab layers are stacked to form tabs. The adapter is disposed between the wall portion and the electrode body and is connected to the electrode terminals. The adapter includes a main body portion and an extension portion, the extension portion extending from the main body portion in a first direction, the first direction, the second direction, and the stacking direction of the multiple electrode sheets are perpendicular to each other, and the multiple tab layers are welded to the adapter to form a welded portion. The welded portion includes a first part and a second part, the first part being located in the main body portion, and at least a portion of the second part being located in the extension portion. In the above structure, since the adapter includes an extension extending from the main body in a first direction, at least a second part of the welded portion formed by welding multiple tab layers to the adapter is disposed on the extension. This allows multiple stacked tab layers to still be connected by the welded portion composed of the first and second parts even when they are misaligned in the first direction. This ensures that each tab layer can still be connected to the adapter through the welded portion even when the multiple tab layers are misaligned in the first direction, enabling the tabs to be reliably connected to the adapter. This improves the connection performance between the tabs and the adapter and helps to improve the reliability of the battery cell. Attached Figure Description

[0026] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings.

[0027] Figure 1 These are schematic diagrams of the vehicle structure provided in some embodiments of this application; Figure 2 This is a schematic diagram showing the disassembled structure of a battery device provided in some embodiments of this application; Figure 3 This is a schematic diagram showing the disassembled battery cell provided in some embodiments of this application; Figure 4 Cross-sectional views of a battery cell provided in some embodiments of this application; Figure 5 This is a bottom view of the adapter in a battery cell provided in some embodiments of this application; Figure 6 This is a schematic diagram of the stacking of the tab layer in a battery cell provided in some embodiments of this application.

[0028] In the diagram: 1. Vehicle; 2. Battery unit; 3. Controller; 4. Motor; 5. Housing; 5a. First housing section; 5b. Second housing section; 5c. Receiving space; 7. Battery cell; 71. Shell; 711. Wall; 712. Injection hole; 713. Flow guiding structure; 714. Pressure relief mechanism; 72. Electrode terminal; 8. Electrode assembly; 81. Electrode body; 811. Bending area; 812. Straight area; 82. Tab; 821. Tab layer; 822. Protrusion structure; 823. Bending structure; 9. Adapter; 91. Connecting part; 92. Main body; 93. Bending part; 94. Extension part; 921. Clearance hole; 10. Welding part; 101. First part; 102. Second part; 11. First insulating element; X. First direction; Y. Second direction; Z. Stacking direction of multiple electrode sheets. Detailed Implementation

[0029] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0030] It should be noted that, unless otherwise stated, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by those skilled in the art to which the embodiments of this application pertain.

[0031] In the description of the embodiments of this 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", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0032] Furthermore, technical terms such as "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of the embodiments of this application, "a plurality of" means two or more, unless otherwise explicitly defined.

[0033] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0034] In the description of the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0035] Currently, judging from market trends, the application of battery devices is becoming increasingly widespread. Battery devices are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power plants, but also widely used in individual battery cells such as energy storage containers or energy storage cabinets. As the application fields of battery devices continue to expand, the requirements for the reliability of battery devices are also constantly increasing.

[0036] The battery apparatus mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells connected in series, parallel, or mixed connections via a busbar.

[0037] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0038] A battery cell can be a rechargeable battery cell, which refers to a battery cell that can be recharged after being discharged to activate the active materials and continue to be used.

[0039] Battery cells can be lithium-ion cells, sodium-ion cells, sodium-lithium-ion cells, lithium metal cells, sodium metal cells, lithium-sulfur cells, magnesium-ion cells, nickel-metal hydride cells, nickel-cadmium cells, lead-acid cells, etc.

[0040] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, prevents short circuits while allowing active ions to pass through.

[0041] The electrode assembly can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0042] As an example, a battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries.

[0043] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form an independent module. As another example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0044] In some embodiments, the battery device may include one or more battery packs, and each battery pack may include one or more individual battery cells. As an example, a battery pack includes a housing and one or more individual battery cells, the individual cells being housed within the housing, for example, by a fixed arrangement. As yet another example, the battery device may include multiple battery packs, which may be connected in series, parallel, or in a mixed configuration.

[0045] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0046] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0047] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0048] In some embodiments, the battery device may be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0049] Typically, the electrode assembly in a battery cell includes stacked positive electrode sheets, negative electrode sheets, and separators. During the process of forming the electrode assembly from these stacked sheets, the electrodes cannot be perfectly aligned, leading to misalignment between multiple tab layers. For example, in battery cells with a wound electrode assembly structure, due to unavoidable errors and variations in electrode tension during the winding process, adjacent tab layers are prone to misalignment after the electrode assembly is formed, preventing multiple tab layers from being perfectly aligned. In some cases, to ensure a good connection between the multiple tab layers and the adapter, the stacked tab layers are typically welded to the adapter. However, when the tab layer is misaligned, some of the tab layer is prone to leaving the welding position, resulting in a smaller welding area on the tab layer. This reduces the connection performance between the tab layer and the adapter, which not only reduces the overcurrent between the tab and the adapter, but also easily leads to an increase in the internal resistance of the battery cell. Furthermore, it makes the connection between the tab and the adapter prone to failure, which is not conducive to improving the reliability of the battery cell.

[0050] To improve the reliability of a single battery cell, some embodiments of this application provide a single battery cell including a casing, electrode terminals, an electrode assembly, and an adapter. The casing includes a wall portion, the electrode terminals are disposed in the wall portion, and the electrode assembly is housed in the casing. The electrode assembly includes an electrode body and tabs. The electrode body includes multiple stacked electrode sheets, and tab layers extend from the ends of the electrode sheets in a second direction, which is perpendicular to the stacking direction of the multiple electrode sheets. The multiple tab layers are stacked to form tabs. The adapter is disposed between the wall portion and the electrode body and connected to the electrode terminals. The adapter includes a main body portion and an extension portion, the extension portion extending from the main body portion along a first direction, the first direction, the second direction, and the stacking direction of the multiple electrode sheets being perpendicular to each other. The multiple tab layers are welded to the adapter to form a welded portion, the welded portion including a first part and a second part, the first part being located in the main body portion, and at least a portion of the second part being located in the extension portion. In the above structure, since the adapter includes an extension extending from the main body in a first direction, at least a second part of the welded portion formed by welding multiple tab layers to the adapter is disposed on the extension. This allows multiple stacked tab layers to still be connected to the welded portion consisting of the first and second parts even when they are misaligned in the first direction. This ensures that each tab layer can still be connected to the adapter through the welded portion even when the multiple tab layers are misaligned in the first direction, enabling the tabs to be reliably connected to the adapter. This improves the connection performance between the tabs and the adapter and helps to improve the reliability of the battery cell.

[0051] The battery cells described in the embodiments of this application are applicable to battery devices and electrical devices that use battery devices.

[0052] Electrical devices can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, among others. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc.

[0053] For ease of explanation, the following embodiments will be described using a vehicle as an example of an electrical device according to an embodiment of this application.

[0054] Figure 1 The diagram shows the structural features of a vehicle provided in some embodiments of this application.

[0055] like Figure 1 As shown, a battery device 2 is installed inside the vehicle 1. The battery device 2 can be located at the bottom, front, or rear of the vehicle 1. The battery device 2 can be used to power the vehicle 1; for example, the battery device 2 can serve as the operating power source for the vehicle 1.

[0056] The vehicle 1 may also include a controller 3 and a motor 4. The controller 3 is used to control the battery device 2 to supply power to the motor 4, for example, for the power needs of the vehicle 1 during starting, navigation and driving.

[0057] In some embodiments of this application, the battery device 2 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0058] Figure 2 This is a schematic diagram showing the disassembled structure of the battery device 2 provided in some embodiments of this application. For example... Figure 2 As shown, the battery device 2 includes a housing 5 and battery cells 7, with the battery cells 7 housed within the housing 5. The battery cell 7 can be the smallest unit that makes up a battery.

[0059] The housing 5 is used to house the battery cell 7, and the housing 5 can have various structures. In some embodiments, the housing 5 may include a first housing portion 5a and a second housing portion 5b, which overlap each other, and together define a housing space 5c for housing the battery cell 7. The second housing portion 5b may be a hollow structure with one end open, and the first housing portion 5a may be a plate-like structure, with the first housing portion 5a covering the open side of the second housing portion 5b to form a housing 5 with the housing space 5c; alternatively, both the first housing portion 5a and the second housing portion 5b may be hollow structures with one side open, with the open side of the first housing portion 5a covering the open side of the second housing portion 5b to form a housing 5 with the housing space 5c. Of course, the first housing portion 5a and the second housing portion 5b can be various shapes, such as cylinders, cuboids, etc.

[0060] To improve the sealing performance after the first housing part 5a and the second housing part 5b are connected, a sealing element, such as sealant or sealing ring, can also be provided between the first housing part 5a and the second housing part 5b.

[0061] Assuming that the first box part 5a covers the top of the second box part 5b, the first box part 5a can also be called the upper box cover, and the second box part 5b can also be called the lower box 5.

[0062] In the battery device 2, there can be one or more battery cells 7. If there are multiple battery cells 7, they can be connected in series, in parallel, or in a mixed manner. A mixed connection means that multiple battery cells 7 are connected in both series and parallel. Multiple battery cells 7 can be directly connected in series, in parallel, or in a mixed manner, and then the whole assembly of multiple battery cells 7 is housed in the housing 5. Alternatively, multiple battery cells 7 can first be connected in series, in parallel, or in a mixed manner to form a battery module, and then multiple battery modules can be connected in series, in parallel, or in a mixed manner to form a whole assembly, which is then housed in the housing 5.

[0063] Some embodiments of this application provide a single battery cell, see reference. Figure 3 and Figure 4The battery cell 7 includes a housing 71, electrode terminals 72, an electrode assembly 8, and an adapter 9. The housing 71 includes a wall 711, and the electrode terminals 72 are disposed in the wall 711. The electrode assembly 8 is housed in the housing 71 and includes an electrode body 81 and tabs 82. The electrode body 81 includes multiple stacked electrode sheets, and tab layers 821 extend from the ends of the electrode sheets in a second direction Y. The second direction Y is perpendicular to the stacking direction Z of the multiple electrode sheets. The multiple tab layers 821 are stacked to form tabs. The adapter 9 is provided with... The adapter 9 is placed between the wall portion 711 and the electrode body 81 and connected to the electrode terminal 72. The adapter 9 includes a main body portion 92 and an extension portion 94. The extension portion 94 extends from the main body portion 92 along a first direction X. The first direction X, the second direction Y, and the stacking direction Z of the multiple electrode sheets are perpendicular to each other. Multiple electrode tab layers 821 are welded to the adapter 9 to form a welding portion 10. The welding portion 10 includes a first part 101 and a second part 102. The first part 101 is located in the main body portion 92, and at least part of the second part 102 is located in the extension portion 94.

[0064] The outer casing 71 may be a component in the battery cell 7 that forms a sealed space to accommodate other components in the battery cell 7. The wall portion 711 may be a portion of the wall in the outer casing 71, which may be provided with components such as electrode terminals 72. Exemplarily, the outer casing 71 may include a housing and a cover, the housing forming a first cavity with an opening, and the cover sealingly sealing the opening, wherein the cover may serve as the wall portion 711.

[0065] The electrode terminal 72 can be a structure for connecting the battery cell 7 to an external electrical device or a charging device, so that the battery cell 7 can provide electrical energy to the external electrical device or the charging device can charge the battery cell 7. The electrode terminal 72 is provided on the wall portion 711. It can be that there is one electrode terminal 72 on the wall portion 711, or there can be two electrode terminals 72 with opposite polarities spaced apart on the wall portion 711.

[0066] Electrode assembly 8 is the component in the battery cell 7 where the electrochemical reaction takes place. The housing 71 can accommodate one or more electrode assemblies 8. Electrode body 81 can be the main part of the electrode assembly 8, and tabs 82 extend from the electrode body 81 for electrical connection with electrode terminals 72 to draw current from the electrode assembly 8.

[0067] The electrode assembly 8 is configured as a wound structure, which means that the electrode body 81 in the electrode assembly 8 is formed by winding a stacked positive electrode sheet, a separator and a negative electrode sheet.

[0068] The electrode body 81 includes a plurality of stacked electrode sheets, meaning that the electrode body 81 can be formed by alternating stacking of positive and negative electrode sheets. Exemplarily, the electrode body 81 can be a stacked structure or a wound structure. A tab layer 821 extends from the end of the electrode sheet in the second direction Y, and the plurality of tab layers 821 are stacked along the stacking direction Z of the plurality of electrode sheets to form tabs 82.

[0069] The second direction Y is set to be perpendicular to the stacking direction Z of the multiple electrodes.

[0070] The adapter 9 can refer to a component used to connect the tab 82 and the electrode terminal 72. It is made of conductive material. By connecting the tab 82 and the electrode terminal 72, the electrode assembly 8 can be electrically connected to the electrode terminal 72, which facilitates the battery cell 7 to output current or input current.

[0071] By providing the adapter 9 between the wall portion 711 and the electrode body 81, the adapter 9 can be connected to the electrode terminal 72 provided on the wall portion 711 and the tab 82 extending from the electrode body 81.

[0072] The adapter 9 is connected to the electrode terminal 72. This can be done by bonding the adapter 9 to the electrode terminal 72 with conductive adhesive or by welding the adapter 9 to the electrode terminal 72. Those skilled in the art can choose the connection method between the adapter 9 and the electrode terminal 72 according to the actual situation so that the adapter 9 and the electrode terminal 72 are electrically connected.

[0073] The main body 92 and the extension 94 are structural parts of the adapter 9. The extension 94 extends from the main body 92 along the first direction X, allowing the adapter to extend in the first direction X, so that the welding part 10 on it can also extend in the first direction X. The first direction X is perpendicular to both the second direction Y and the stacking direction Z of the multiple electrodes, so that the extension of the welding part 10 in the first direction X can accommodate the misalignment of the multiple stacked electrodes in the first direction X.

[0074] Multiple tab layers 821 are welded to the adapter 9 to form a welded portion 10. This can mean that multiple tab layers 821 are stacked and welded together to form an integral structure, while simultaneously being welded to the adapter 9, forming the welded portion 10 on the adapter 9. The first part 101 and the second part 102 are two parts of the welded portion 10. The first part 101 and the second part 102 can be connected to each other or spaced apart, depending on the actual situation. The first part 101 is disposed on the main body 92, and at least a portion of the second part 102 is disposed on the extension 94. At least a portion of the second part 102 being located on the extension 94 can mean that the entire second part 102 is disposed on the extension 94, or it can mean that a portion of the second part 102 is disposed on the extension 94, and another portion of the second part 102 is disposed on the main body 92.

[0075] By providing the first part 101 on the main body 92 and at least a portion of the second part 102 on the extension 94, the first part 101 and the second part 102 are arranged along the first direction X, allowing the welding part 10 to extend to a certain extent along the first direction X. By arranging the first part 101 and the second part 102 along the first direction X, the welding part 10 can extend in the first direction X, ensuring that even if the tab layers 821 are misaligned in the first direction X, each tab layer 821 still has a welding part 10, enabling connection with the adapter 9 via the welding part 10.

[0076] In the above structure, since the adapter 9 includes an extension 94 extending from the main body 92 along the first direction X, at least a second part 102 of the welding part 10 formed by welding multiple tab layers 821 to the adapter 9 is disposed on the extension 94. This allows the multiple stacked tab layers 821 to still be connected by the welding part 10 composed of the first part 101 and the second part 102 even when they are misaligned in the first direction X. This ensures that even if the multiple tab layers 821 are misaligned in the first direction X, each tab layer 821 can still be connected to the adapter 9 through the welding part 10. This allows the tabs 82 to be reliably connected to the adapter 9, improving the connection performance between the tabs 82 and the adapter 9, and thus improving the reliability of the battery cell 7.

[0077] In some embodiments, the second direction Y extends from the electrode body 81 to the wall portion 711, the wall portion 711 is provided with an injection hole 712, the injection hole 712 penetrates the wall portion 711 along the second direction Y, and the injection hole 712 and the electrode terminal 72 are arranged along the first direction X; the adapter 9 is provided with a clearance hole 921 that penetrates along the second direction Y, and in the second direction Y, the orthographic projection of the injection hole 712 is located within the range of the orthographic projection of the clearance hole 921.

[0078] By setting the second direction Y to point from the electrode body 81 to the wall portion 711, the tab 82 extending from the end of the straight region 812 in the second direction Y extends toward the wall portion 711, so that the tab 82 can be easily connected to the electrode terminal 72 on the wall portion 711.

[0079] The injection hole 712 can be a perforated structure for injecting electrolyte into the housing 71. The injection hole 712 is a perforated structure provided on the wall portion 711. By making the injection hole 712 penetrate the wall portion 711 along the second direction Y, the electrolyte located outside the housing 71 can be injected into the housing 71 through the injection hole 712 of the wall portion 711.

[0080] By arranging the injection hole 712 and the electrode terminal 72 along the first direction X, the injection hole 712 and the electrode terminal 72 can be conveniently arranged on the wall portion 711.

[0081] The clearance hole 921 can be a hole-like structure provided on the adapter 9, which is used to allow the electrolyte injected into the housing 71 from the injection hole 712 to flow smoothly to the electrode body 81. This not only speeds up the efficiency of electrolyte injection, but also allows the electrolyte to fully wet the electrode body 712.

[0082] In the second direction Y, the orthographic projection of the injection hole 712 is located within the range of the orthographic projection of the clearance hole 921. This means that along the second direction Y, the injection hole 712 and the clearance hole 921 are directly opposite each other, and the orthographic projection of the injection hole 712 falls within the range of the orthographic projection of the clearance hole 921, so that the adapter 9 is less likely to affect the smooth flow of electrolyte injected from the injection hole 712.

[0083] In some embodiments, reference Figure 5 The extension 94 is disposed on one side of the clearance hole 921 in the stacking direction of the multiple electrodes.

[0084] The extension 94 is disposed on one side of the clearance hole 921 in the stacking direction of the multiple electrodes. This means that the extension 94 is located on one side of the clearance hole 921 in the stacking direction of the multiple electrodes, so that the welding part 10 can make full use of the space on the adapter 9 through the second part 102, which is beneficial to improving the utilization rate of the adapter 9 and thus reducing the area of ​​the adapter 9. For example, the second part 102 may be provided on one side of the clearance hole 921 in the stacking direction of the multiple electrodes, or the second part 102 may be provided on both sides of the clearance hole 921 in the stacking direction of the multiple electrodes.

[0085] In some embodiments, a clearance hole 921 is provided on the main body portion 92, and the clearance hole 921 communicates with the end face of the extension portion 94 extending from the main body portion 92.

[0086] By providing the clearance hole 921 on the main body 92, the clearance hole 921 is less likely to affect the connection between the adapter 9 and the electrode terminal 72, which helps to improve the firmness of the connection between the adapter 9 and the motor terminal.

[0087] The clearance hole 921 is connected to the end face of the extension 94 of the main body 92. This means that the clearance hole 921 can extend along the first direction X to the end face of the extension 94 and communicate with the end face of the extension 94 of the main body 92. This allows the clearance hole 921 to provide a larger clearance space, which not only allows the clearance hole 921 to better avoid the flow guiding structure 713, but also makes it easier to install the main body 92 in the battery cell 7.

[0088] In some embodiments, two extensions 94 are provided, and the two extensions 94 are disposed opposite each other on both sides of the clearance hole 921 along the stacking direction Z of the plurality of electrodes.

[0089] By providing two extensions 94 extending from the main body 92 along the first direction X, and by positioning the two extensions 94 at relative intervals on both sides of the clearance hole 921 along the stacking direction Z of the plurality of electrodes, the gap between the two extensions 94 can serve as the clearance hole 921.

[0090] In some embodiments, in the stacking direction Z of the plurality of electrodes, the maximum size of the first part 101 is greater than the maximum size of the second part 102.

[0091] Since the extension 94 is a structural part that extends from the main body 92 along the first direction X, the dimension of the extension 94 in the stacking direction Z of the multiple electrodes is smaller than the dimension of the main body 92 in the stacking direction Z of the multiple electrodes. By setting the maximum dimension of the first part 101 in the stacking direction Z of the multiple electrodes to be greater than the maximum dimension of the second part 102 in the stacking direction Z of the multiple electrodes, a larger first part 101 can be provided on the main body 92, which is beneficial to increase the area of ​​the welding part 10 and improve the reliability of the connection between the electrode tab 82 and the adapter 9.

[0092] In some embodiments, the size of the second part 102 along the first direction X is set to L, where 10mm≤L≤20mm.

[0093] By setting the size L of the second part 102 along the first direction X to 10mm≤L≤20mm, not only can the second part 102 be increased to a sufficient size for the welding part 10 in the first direction X, so that the multiple stacked tab layers 821 can still be connected to the welding part 10 when they are misaligned in the first direction X, but the size of the second part 102 in the first direction X does not have to be too large and occupy too much space inside the battery cell 7.

[0094] The size L of the second part 102 along the first direction X is set to 13mm≤L≤18mm. For example, the size L of the second part 102 along the first direction X can be set to 13mm, 15mm or 18mm, so that the second part 102 can not only increase the size of the welding part 10 in the first direction X, but also will not occupy too much space inside the battery cell 7.

[0095] In some embodiments, in the tab 82 welded to the welding part 10, the number of layers of the tab layer 821 is set to D, where D≥3.

[0096] By setting the range of the number of layers D of the electrode layer 821 in the electrode tab 82 welded to the welding part 10 to D≥3, the electrode layer 821 in the electrode tab 82 welded to the welding part 10 has a sufficient number of layers, so that the electrode tab 82 here has sufficient structural strength and thickness, so that the electrode tab 82 is not easily welded through when the adapter 9 is welded to the electrode tab 82, which is beneficial to improving the welding quality of the adapter 9 and the electrode tab 82.

[0097] In some embodiments, the area of ​​the tab layer 821 is set to A, and the area of ​​the tab layer 821 connected to the welding part 10 is set to B, where 0.5 ≤ B / A ≤ 0.8.

[0098] By setting the area of ​​the tab layer 821 to A, setting the area of ​​the tab layer 821 connected to the welding part 10 to B, and setting the relationship between the two to 0.5≤B / A≤0.8, not only is sufficient area on each tab layer 821 to connect with the welding part 10, which is beneficial to improving the connection strength and current carrying capacity between the tab 82 and the adapter 9, but also the process difficulty caused by excessively increasing the area of ​​the welding part 10 can be reduced.

[0099] In some embodiments, the relationship between the area A of the tab layer 821 and the area B of the weld portion 10 on the tab layer 821 can be set to 0.5 ≤ B / A ≤ 0.7. For example, B / A can be 0.5, 0.6, or 0.7, so that each tab layer 821 has a sufficient area of ​​weld portion 10 while reducing the process difficulty caused by excessively increasing the area of ​​the weld portion 10.

[0100] In some embodiments, the second part 102 is connected to the first part 101.

[0101] The second part 102 is connected to the first part 101. This means that the second part 102 and the first part 101 are integrally formed, so that the welding part 10 can form an integral structure. This not only helps to improve the overall structural strength of the welding part 10, but also enables the welding part 10 with the first part 101 and the second part 102 to be formed by a welding head, which helps to improve the welding efficiency between the adapter 9 and the electrode 82.

[0102] In some embodiments, reference Figure 6 The tab 82 includes an extension structure 822 and a bending structure 823 connected to each other. The extension structure 822 extends from the electrode body 81 along the second direction Y, and the bending structure 823 bends relative to the second direction Y and abuts against the surface of the adapter 9 facing the electrode body 81.

[0103] The protruding structure 822 and the bending structure 823 can be two different parts that are connected to each other in the tab 82. The protruding structure 822 is the part of the tab 82 that extends from the electrode body 81 along the second direction Y, and the bending structure 823 is the part of the tab 82 that is bent relative to the second direction Y and abuts against the surface of the adapter 9 facing the electrode body 81.

[0104] The protruding structure 822 extends from the electrode body 81 along the second direction Y. Specifically, the protruding structure 822 extends from the electrode body 81 toward the wall portion 711, allowing the tab 82 to approach the electrode terminal 72 disposed on the wall portion 711. The bending structure 823, by bending relative to the second direction Y, increases the area abutting against the adapter 9, thereby enhancing the current-carrying capacity between the adapter 9 and the electrode terminal 72.

[0105] In some embodiments, the wall portion 711 is provided with a pressure relief mechanism 714, which is arranged with the electrode terminal 72 along a first direction X; in the second direction Y, the orthographic projection of the pressure relief mechanism 714 does not overlap with the orthographic projection of the adapter 9.

[0106] The pressure relief mechanism 714 can be a mechanism for releasing internal gas from the battery cell 7. As an example, it is actuated to release internal pressure or temperature when the internal pressure or temperature of the battery cell 7 reaches a predetermined threshold. When the internal pressure or temperature of the battery cell 7 reaches the predetermined threshold, the pressure relief mechanism 714 performs an action or a weak structure provided in the pressure relief mechanism 714 is broken, thereby forming an opening or channel for releasing internal pressure or temperature. This threshold design varies depending on design requirements. Exemplarily, the pressure relief mechanism 714 can be integrally formed with the wall portion 711. In some embodiments, the pressure relief mechanism 714 can also be separately provided and connected to the wall portion 711.

[0107] The pressure relief mechanism 714 and the electrode terminal 72 are arranged along the first direction X, meaning that the pressure relief mechanism 714 is disposed on one side of the electrode terminal 72 in the first direction X. For example, two electrode terminals 72 may be provided on the wall portion 711 along the first direction X, and the pressure relief mechanism 714 may be disposed between the two electrode terminals 72. By arranging the pressure relief mechanism 714 and the electrode terminal 72 along the first direction X, the various components on the wall portion 711 can be arranged in an orderly manner.

[0108] By ensuring that the orthographic projection of the pressure relief mechanism 714 in the second direction Y does not overlap with the orthographic projection of the adapter 9 in the second direction Y, the adapter 9 is less likely to affect the operation of the pressure relief mechanism 714, thus ensuring that the pressure relief mechanism 714 has sufficient discharge area, which is beneficial to improving the reliability of the battery cell 7.

[0109] In some embodiments, the electrode assembly 8 is configured as a wound structure, the electrode body includes two bent regions 811 disposed opposite each other along a first direction X and a straight region 812 connected between the two bent regions 811, and the tab 82 is connected to the end of the straight region 812 in a second direction Y.

[0110] The bending region 811 and the straight region 812 are different areas within the electrode body 81. The straight region 812 can refer to the area where the electrode sheet extends straight within the electrode body 81, while the bending region 811 can refer to the area where the electrode sheet extends bent within the electrode body 81. By including two bending regions 811 arranged opposite each other along a first direction X in the electrode body 81, and connecting the straight region 812 between the two bending regions 811, the bending regions 811 and the straight region 812 can form an electrode body 81 with a wound structure. Here, the first direction X is the winding direction of the electrode sheet in the straight region 812.

[0111] The tab 82 is connected to the end of the flat region 812 in the second direction Y. This can mean that the tab 82 extends outward from the flat region 812 of the electrode body 81 and extends from the end of the electrode body 81 in the second direction Y.

[0112] By setting the second direction Y to be perpendicular to the first direction X, the tab 82 does not extend from the bending area 811 located at the end of the electrode body 81 in the first direction X, so that the tab 82 can extend from the appropriate position (straight area 812) of the electrode body 81.

[0113] The tabs 82 formed by multiple tab layers 821 extend out of the flat region 812, and the winding direction of the electrode sheet in the flat region 812 is the first direction X, so that the misalignment of the tab layer 821 caused by winding is also in the first direction X.

[0114] In some embodiments, the adapter 9 further includes a connecting portion 91 connected to the side of the main body 92 away from the extension 94 along the first direction X, and the connecting portion 91 is connected to the electrode terminal 72.

[0115] The connecting part 91 is connected to the side of the main body 92 away from the extension 94 along the first direction X, so that the connecting part 91, the main body 92 and the extension 94 are connected in sequence in the first direction X.

[0116] The connection part 91 is connected to the electrode terminal 72. This means that the connection part 91 is connected to the surface of the electrode terminal 72 facing the electrode body 81, so that the adapter 9 can be easily connected to the electrode terminal 72.

[0117] For example, the connecting part 91, the main body 92, and the extension 94 can be an integrally formed structure. The connecting part, the main body 92, and the extension 94 can be manufactured by integral forming processing methods such as stamping, so that the adapter 9 can be manufactured as a whole and synchronously. This not only makes the processing and manufacturing of the adapter 9 convenient, but also gives the overall structure of the adapter 9 good strength. The connecting part 91, the main body 92, and the extension 94 can be manufactured by machining methods such as milling, by processing a whole blank, so that the adapter 9 has low processing difficulty and low processing cost.

[0118] In some embodiments, the battery cell 7 further includes a first insulating member 11 connected to the wall portion 711, at least a portion of the first insulating member 11 being disposed between the wall portion 711 and the adapter 9, and the electrode terminal 72 passing through the first insulating member 11 and connected to the connecting portion 91.

[0119] The first insulating member 11 is a component with insulating properties, used to insulate and isolate the wall portion 711 from the electrode assembly 8, thereby reducing the possibility of the wall portion 711 becoming charged. The first insulating member 11 is connected to the wall portion 711, meaning that the first insulating member 11 is connected to the surface of the wall portion 711 facing the electrode body 81. Exemplarily, the first insulating member 11 can be injection molded onto the surface of the wall portion 711 facing the electrode body 81. At least a portion of the first insulating member 11 is disposed between the wall portion 711 and the adapter 9, meaning that at least a portion of the first insulating member 11 is located between the wall portion 711 and the adapter 9, such that the first insulating member 11 can insulate and isolate the wall portion 711 from the adapter 9.

[0120] By connecting the electrode terminal 72 to the connection portion 91 through the first insulating member 11, the electrode terminal 72 can be connected to the connection portion 91 through the first insulating member 11 used for insulation isolation.

[0121] In some embodiments, the second direction Y extends from the electrode body 81 to the wall portion 711. The wall portion 711 is provided with an injection hole 712, which penetrates the wall portion 711 along the second direction Y. The injection hole 712 and the electrode terminal 72 are arranged along the first direction X. The adapter 9 is provided with a clearance hole 921 that penetrates along the second direction Y. The first insulating member 11 is provided with a flow guiding structure 713, which is disposed opposite to the injection hole 712 along the second direction Y. At least a portion of the flow guiding structure 713 extends into the clearance hole 921.

[0122] The flow guiding structure 713 can be a structure for guiding the electrolyte injected from the injection hole 712, which enables the electrolyte to diffuse better in the housing 71, allowing the electrolyte to better wet the electrode assembly 8. By arranging the flow guiding structure 713 opposite to the injection hole 712 along the second direction Y, the flow guiding structure 713 has a better guiding effect on the electrolyte injected from the injection hole 712.

[0123] Since the first insulating member 11 is connected to the wall portion 711 facing the electrode body 81, and the injection hole 712 is opposite to the clearance hole 921 along the second direction Y, by arranging the flow guiding structure 713 opposite to the injection hole 712, such that the flow guiding structure 713 is located on one side of the injection hole 712 in the second direction Y, and the flow guiding structure 713 is connected to the side of the wall portion 711 facing the electrode body 81, and at least a portion of the flow guiding structure 713 is opposite to the injection hole 712 along the second direction Y and extends into the clearance hole 921, the possibility of interference between the flow guiding structure 713 and the adapter 9 can be reduced. By passing through the adapter 9 along the second direction Y, the clearance hole 921 can better avoid the flow guiding structure 713 located on the second direction Y side of the injection hole 712.

[0124] At least a portion of the flow guiding structure 713 extends into the clearance hole 921. This can mean that a portion of the flow guiding structure 713 extends into the clearance hole 921, or that the entire flow guiding structure 713 extends into the clearance hole 921. By having at least a portion of the flow guiding structure 713 extend into the clearance hole 921, the adapter 9 can avoid the flow guiding structure 713 through the clearance hole 921. This allows the adapter 9 to extend over a larger area without interfering with the flow guiding structure 713. This facilitates the provision of a larger area for welding the adapter 9 to multiple tab layers 821, and helps improve the current flow capacity at the connection between the adapter 9 and the tab 82.

[0125] In some embodiments, in the second direction Y, a portion of the electrode terminal 72 protrudes from the first insulating member 11. The adapter 9 also includes a bent portion 93 connecting the connecting portion 91 and the main body portion 92. The bent portion 93 bends toward the connecting portion 91 relative to the main body portion 92. The connecting portion 91 is closer to the electrode body 81 than the main body portion 92. The connecting portion 91 is located on the side of the electrode terminal 72 that is closer to the electrode body 81.

[0126] The fact that some electrode terminals 72 protrude from the first insulating member 11 means that some electrode terminals 72 extend outside the first insulating member 11, so that the electrode terminals 72 can be easily connected to the connecting part 91.

[0127] The bending portion 93 can be a partial structure used to connect the connecting portion 91 and the main body portion 92. By bending the bending portion 93 relative to the main body portion 92 toward the connecting portion 91, the bending portion 93 can connect the connecting portion 91 and the main body portion 92 located on different planes.

[0128] By positioning the connecting portion 91 closer to the electrode body 81 than the main body portion 92, the connecting portion 91 can be located on the side of the electrode terminal 72 that is closer to the electrode body 81, making it easier to connect the connecting portion 91 to the surface of the electrode terminal 72 that is closer to the electrode body 81.

[0129] Some embodiments of this application also provide a battery device 2, which includes the battery cell 7 provided by the above-described technical solution.

[0130] Some embodiments of this application also provide an electrical device, which includes the battery device 2 provided by the above-described technical solution, the battery device 2 being used to provide electrical energy.

[0131] Some embodiments of this application provide a battery cell 7, which includes a housing 71, electrode terminals 72, an electrode assembly 8, and an adapter 9. The housing 71 includes a wall portion 711, and the electrode terminals 72 are disposed on the wall portion 711. The electrode assembly 8, configured as a wound structure, is housed in the housing 71. The electrode assembly 8 includes an electrode body 81 and tabs 82. The electrode body 81 includes two bending regions 811 disposed opposite each other along a first direction X and a straight region 812 connecting the two bending regions 811. The tabs 82 are disposed from the straight region 812. The straight section 812 extends out from the end in the second direction Y, which is perpendicular to the first direction X. The adapter 9 is disposed between the wall portion 711 and the electrode body 81. The adapter 9 is connected to the electrode terminal 72. Multiple stacked tab layers 821 in the tab 82 are welded to the adapter 9 to form a welding portion 10. The adapter includes a main body portion 92 and an extension portion 94 extending from the main body portion 92 along the first direction X. The first part 101 and the second part 102, which are interconnected in the welding portion 10, are respectively disposed in the main body portion 92 and the extension portion 94. The wall portion 711 is provided with a liquid injection hole 712 that extends through the wall portion 711 along the second direction Y. The liquid injection hole 712 and the electrode terminal 72 are arranged along the first direction X. The wall portion 711 is connected to a flow guiding structure 713, which is located on one side of the liquid injection hole 712 in the second direction Y. The adapter 9 is provided with a clearance hole 921 that extends through the second direction Y. At least part of the flow guiding structure 713 extends into the clearance hole 921. The second part 102 is provided on both sides of the clearance hole 921 in the stacking direction of the multiple electrodes. The stacking direction of the multiple electrodes, the second direction Y, and the first direction X are perpendicular to each other.

[0132] In the above structure, since the adapter 9 includes an extension 94 extending from the main body 92 along the first direction X, at least a second part 102 of the welding part 10 formed by welding multiple tab layers 821 to the adapter 9 is disposed on the extension 94. This allows the multiple stacked tab layers 821 to still be connected by the welding part 10 composed of the first part 101 and the second part 102 even when they are misaligned in the first direction X. This ensures that even if the multiple tab layers 821 are misaligned in the first direction X, each tab layer 821 can still be connected to the adapter 9 through the welding part 10. This allows the tabs 82 to be reliably connected to the adapter 9, improving the connection performance between the tabs 82 and the adapter 9, and thus improving the reliability of the battery cell 7.

[0133] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: The outer casing, including the walls; Electrode terminals are disposed on the wall portion; An electrode assembly is housed in the housing. The electrode assembly includes an electrode body and tabs. The electrode body includes a plurality of stacked electrode plates. Each electrode plate has a tab layer extending from its end in a second direction, which is perpendicular to the stacking direction of the plurality of electrode plates. The plurality of tab layers are stacked to form the tabs. An adapter is disposed between the wall portion and the electrode body. The adapter is connected to the electrode terminal. The adapter includes a main body portion and an extension portion. The extension portion extends from the main body portion along a first direction. The first direction, the second direction, and the stacking direction of the plurality of electrode sheets are perpendicular to each other. The plurality of electrode tab layers are welded to the adapter to form a welded portion. The welded portion includes a first part and a second part. The first part is located in the main body portion, and at least a portion of the second part is located in the extension portion.

2. The battery cell according to claim 1, characterized in that, The second direction extends from the electrode body to the wall portion, the wall portion is provided with an injection hole, the injection hole penetrates the wall portion along the second direction, and the injection hole and the electrode terminal are arranged along the first direction; the adapter is provided with a clearance hole penetrating along the second direction, and in the second direction, the orthographic projection of the injection hole is located within the range of the orthographic projection of the clearance hole.

3. The battery cell according to claim 2, characterized in that, The extension is disposed on one side of the clearance hole in the stacking direction of the plurality of electrodes.

4. The battery cell according to claim 2, characterized in that, The clearance hole is provided on the main body and communicates with the end face of the main body that extends out of the extension.

5. The battery cell according to claim 2, characterized in that, The extension portion is provided in two parts, and the two extension portions are arranged opposite each other on both sides of the clearance hole along the stacking direction of the plurality of electrodes.

6. The battery cell according to any one of claims 1-5, characterized in that, In the stacking direction of the plurality of electrodes, the maximum size of the first part is greater than the maximum size of the second part.

7. The battery cell according to any one of claims 1-5, characterized in that, Along the first direction, the size of the second part is set to L, where 10mm≤L≤20mm.

8. The battery cell according to any one of claims 1-7, characterized in that, In the electrode region welded to the welding part, the number of electrode layers is set to D, where D≥3.

9. The battery cell according to any one of claims 1-8, characterized in that, The area of ​​the tab layer is set to A, and the area where the tab layer is connected to the welding part is set to B, where 0.5≤B / A≤0.

8.

10. The battery cell according to any one of claims 1-9, characterized in that, The second part is connected to the first part.

11. The battery cell according to any one of claims 1-10, characterized in that, The tab includes an extended structure and a bent structure connected to each other. The extended structure extends from the electrode body along the second direction, and the bent structure bends relative to the second direction and abuts against the surface of the adapter facing the electrode body.

12. The battery cell according to any one of claims 1-11, characterized in that, The wall portion is provided with a pressure relief mechanism, which is arranged along the first direction with the electrode terminal; in the second direction, the orthographic projection of the pressure relief mechanism does not overlap with the orthographic projection of the adapter.

13. The battery cell according to any one of claims 1-12, characterized in that, The electrode assembly is configured as a wound structure, and the electrode body includes two bent regions arranged opposite each other along the first direction and a straight region connected between the two bent regions. The tab is connected to the end of the straight region in the second direction.

14. The battery cell according to any one of claims 1-13, characterized in that, The adapter further includes a connecting portion connected to the side of the main body away from the extension portion along the first direction, and the connecting portion is connected to the electrode terminal.

15. The battery cell according to claim 14, characterized in that, The battery cell further includes a first insulating member connected to the wall portion, at least a portion of the first insulating member being disposed between the wall portion and the adapter, and the electrode terminal passing through the first insulating member and connected to the connecting portion.

16. The battery cell according to claim 15, characterized in that, The second direction extends from the electrode body to the wall portion, the wall portion is provided with a liquid injection hole, the liquid injection hole penetrates the wall portion along the second direction, the liquid injection hole and the electrode terminal are arranged along the first direction, the adapter is provided with a clearance hole penetrating along the second direction, the first insulating member is provided with a flow guiding structure, along the second direction, the flow guiding structure is arranged opposite to the liquid injection hole, and at least part of the flow guiding structure extends into the clearance hole.

17. The battery cell according to claim 15, characterized in that, In the second direction, a portion of the electrode terminal protrudes from the first insulating member, and the adapter further includes a bent portion connecting the connecting portion and the main body portion. The bent portion bends toward the connecting portion relative to the main body portion. The connecting portion is closer to the electrode body than the main body portion, and the connecting portion is located on the side of the electrode terminal closer to the electrode body portion.

18. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-17.

19. An electrical appliance, characterized in that, Includes the battery device as described in claim 18, the battery device being used to provide electrical energy.

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