Battery cell, method and device for manufacturing same, battery, and electrical device

Abstract

A battery cell (100), a manufacturing method and device thereof, a battery (200), and an electrical device. The battery cell (100) includes: a housing (101); an end cap assembly (102) including an end cap body (1021) and electrode terminals (1022) insulatedly connected to the end cap body (1021); and an electrode assembly (10) disposed in the housing (101) and including: a first electrode plate (1) and a second electrode plate (2) with opposite polarities. The first electrode plate (1) includes a first main body portion (11) and a first tab (12) protruding from the first main body portion (11). The second electrode plate (2) includes a second main body portion (21) and a second tab (22) protruding from the second main body portion (21). The first electrode plate (1) and the second electrode plate (2) are configured to be wound around a winding axis (K) such that the first main body portion (11) and the second main body portion (21) are superimposed to form a wound body (S). One end of the wound body (S) includes a first conductive region (112) and a second conductive region (113). The first tab (12) is led out from the first conductive region (112), and the second tab (22) is led out from the second conductive region (113). The adjacent first conductive region (112) and second conductive region (113) are spaced apart along the radial direction of the wound body (S). Among them, the first tab (12) is electrically connected to the terminal (1022), and the second tab (22) is electrically connected to the end cap body (1021).

Description

Technical Field

[0001] This application relates to the technical field of batteries, and particularly to a battery cell, a manufacturing method and device thereof, a battery, and an electrical device. Background Art

[0002] Due to the advantages of high energy density, high power density, many cycle usage times, long storage time, etc. of lithium-ion and other batteries, they have been widely used in electric vehicles.

[0003] However, improving the working performance of the batteries of electric vehicles has always been a difficult problem in the industry. Summary of the Invention

[0004] The purpose of this application is to improve the performance of the battery.

[0005] According to the first aspect of this application, a battery cell is provided, including:

[0006] A housing having an opening;

[0007] An end cap assembly for closing the opening, the end cap assembly including an end cap body and electrode terminals provided on the end cap body; and

[0008] An electrode assembly provided in the housing and including: a first pole piece and a second pole piece with opposite polarities. The first pole piece includes a first main body portion and a first pole tab protruding from the first main body portion, and the second pole piece includes a second main body portion and a second pole tab protruding from the second main body portion. The first pole piece and the second pole piece are configured to be wound around a winding axis so that the first main body portion and the second main body portion are superposed to form a wound body; one end of the wound body includes a first conductive region and a second conductive region. The first pole tab is led out in the first conductive region, and the second pole tab is led out in the second conductive region. The adjacent first conductive region and second conductive region are arranged at intervals along the radial direction of the wound body;

[0009] Wherein, the first pole tab is electrically connected to the electrode terminal, and the second pole tab is electrically connected to the end cap body.

[0010] In this embodiment, the first pole tab and the second pole tab are led out from the same end of the wound body, only the electrical connection space needs to be reserved at one end of the electrode assembly, and it also saves the setting of electrode terminals at both ends of the battery cell respectively, which can effectively improve the overall energy density of the battery cell. When the capacity of the battery cell is certain, the volume of the battery cell can be reduced, making it easier to layout the battery in the electrical device.

[0011] Moreover, only one electrode terminal is provided for such a battery cell. The first tab is electrically connected to the electrode terminal, and the second tab is directly electrically connected to the end cap body, which can simplify the structure and assembly process of the battery cell. By eliminating one electrode terminal, a larger space can be left on the end cap body, which is conducive to arranging the liquid injection component and the pressure relief component on the end cap body, and also leaves sufficient space for arranging the temperature acquisition component, the bus bar between battery cells, and various wires. It is also beneficial to increase the cross-sectional area of the electrode terminal to increase the overcurrent capacity of the battery cell. This design has greater advantages when the area of the end cap body is small.

[0012] In addition, the first tab and the second tab are arranged at a radial interval, which is conducive to increasing the circumferential extension dimension of the first tab and the second tab along the winding body, improving the connection strength between the tab and the winding body, enabling the root of the tab to have a good self-supporting effect, reducing the wrinkling phenomenon of the tab during the process of applying a circumferential force to flatten the tab, making the shape of the flattened area stable, optimizing the electrical connection effect between the first tab and the electrode terminal, and between the second tab and the end cap body, ensuring reliable power transmission from the electrode assembly to the outside, and improving the overcurrent capacity.

[0013] In some embodiments, the first conductive region is located radially inside the second conductive region.

[0014] This embodiment enables the first tab to be led out from the middle area of the winding body, so that the electrode terminal is located at a position on the end cap body close to the middle area, leaving the surrounding area for arranging the liquid injection component and the pressure relief component, and also leaving sufficient space for arranging the temperature acquisition component, the bus bar between battery cells, and various wires. It is also beneficial to increase the cross-sectional area of the electrode terminal to increase the overcurrent capacity of the battery cell. Optionally, the first conductive region is located radially outside the second conductive region.

[0015] In some embodiments, a first groove is provided on the surface of the electrode terminal away from the electrode assembly. The first groove is recessed in the direction close to the electrode assembly. A first welding portion is formed between the bottom surface of the first groove and the surface of the electrode terminal close to the electrode assembly. The first tab is welded to the first welding portion.

[0016] In this embodiment, by providing the first groove on the electrode terminal, the thickness of the electrode terminal in the welding area is reduced, and after the end cap assembly is installed on the housing, welding can be directly performed from the outside of the electrode terminal, which simplifies the assembly process and can improve the firmness of welding to reliably achieve the electrical connection between the electrode terminal and the first tab.

[0017] In some embodiments, a second groove is provided on the surface of the end cap body away from the electrode assembly. The second groove is recessed in the direction close to the electrode assembly. A second welding portion is formed between the bottom surface of the second groove and the surface of the end cap body close to the electrode assembly. The second tab is welded to the second welding portion.

[0018] In this embodiment, by providing a second groove on the end cap body, the thickness of the end cap body in the welding area is thinned, enabling direct welding from the outside of the end cap body after the end cap assembly is installed on the housing, simplifying the assembly process, and improving the welding firmness to reliably achieve the electrical connection between the end cap body and the second tab.

[0019] In some embodiments, there are multiple second grooves, and the multiple second grooves are arranged at intervals along the circumferential direction of the winding body.

[0020] In this embodiment, multiple second grooves are arranged at intervals along the circumferential direction on the end cap body, which can not only improve the reliability of the electrical connection between the second tab and the end cap body. For example, when welding is used to achieve electrical connection, setting multiple welding positions can ensure the welding strength and prevent the welding positions from loosening when the battery is vibrated and impacted during use. Moreover, other components such as a liquid injection component and a pressure relief component can be arranged between two adjacent second grooves, making full use of the space on the end cap body.

[0021] In some embodiments, the battery cell further includes an adapter. The first tab is electrically connected to the electrode terminal through the adapter, and / or the second tab is electrically connected to the end cap body through the adapter.

[0022] In this embodiment, by providing the adapter, the requirements for the positional relationship between the first tab and the electrode terminal, and between the second tab and the end cap body can be reduced, thereby reducing the process difficulty of electrical connection. Moreover, since multiple tabs are relatively fluffy, it is easier to improve the connection reliability through the adapter to increase the current-carrying capacity of the inner and outer ring tabs. For example, when welding is used for electrical connection, the welding trajectory between the adapter and the tab can be controlled to improve the welding firmness. In addition, damage to the tab or the winding body during electrical connection can be prevented. For example, when welding, it can prevent the welding energy from burning the tab, deforming the winding body, or causing the coating layer on the first main body part and the second main body part to fall off.

[0023] In some embodiments, the first tab winds at least one full turn, and / or the second tab winds at least one full turn.

[0024] In this embodiment, the tab continuously extends and winds at least one turn, having good connection strength with the winding body in the circumferential direction, enabling the tab root to have good self-supporting effect. During the process of applying a circumferential force to flatten the tab, it can prevent the tab from wrinkling, making the shape of the flattened area stable, optimizing the welding effect between the first tab and the electrode terminal and between the second tab and the end cap body, ensuring that the electrode assembly reliably transmits electrical energy outward, and improving the current-carrying capacity. In addition, the particles generated during tab welding are not easily dropped along the circumferential direction between the first electrode plate and the second electrode plate in the liquid guide area, which can improve the reliability of the electrode assembly operation and prevent problems such as short circuit or electrode plate scratching.

[0025] In addition, by providing continuous first tab ears on a partial winding length of the first main body portion and continuous second tab ears on a partial winding length of the second main body portion, the current-carrying capacities of the first tab ears and the second tab ears can be satisfied, and there is no need to provide discrete tab ears on the entire winding length of the main body portion, which can simplify the process of die-cutting the tabbed pole pieces. At the same time, when the first tabbed pole piece and the second tabbed pole piece are wound to form a wound main body, there is no need to perform tab ear alignment, which can simplify the process and improve the production efficiency of the electrode assembly.

[0026] In some embodiments, the first tab ears wind multiple turns in the first conductive region, and / or the second tab ears wind multiple turns in the second conductive region.

[0027] In this embodiment, by winding the tab ears multiple turns in the conductive region, after being flattened, the bent portions of adjacent tab ear layers in the tab ears overlap each other, further strengthening the supporting effect on the tab ears, preventing the tab ears from being flattened and wrinkled, stabilizing the shape of the bent portions, and optimizing the welding effect between the first tab ears and the electrode terminals and between the second tab ears and the end cap body. Moreover, the welding area between the tab ears and the electrode terminals or the end cap body after being flattened can be increased, making the welding between the first tab ears and the electrode terminals and between the second tab ears and the end cap body more firm, ensuring that the electrode assembly reliably transmits electric energy outward, and improving the current-carrying capacity.

[0028] In some embodiments, a plurality of first tab ears are arranged at intervals along the winding direction on the first tabbed pole piece, and the plurality of first tab ears form at least one first tab ear group. At least one first tab ear group is provided in the first conductive region, and the first tab ear group is correspondingly arranged with the first conductive region. The first tab ear group extends along a partial circumference of the wound main body and includes a plurality of first tab ears stacked along the radial direction; and / or a plurality of second tab ears are arranged at intervals along the winding direction on the second tabbed pole piece, and the plurality of second tab ears form at least one second tab ear group. At least one second tab ear group is provided in the second conductive region, and the second tab ear group is correspondingly arranged with the second conductive region. The second tab ear group extends along a partial circumference of the wound main body and includes a plurality of second tab ears stacked along the radial direction.

[0029] The tab ear lead-out method of this embodiment can reduce the weight of the electrode assembly on the basis of ensuring the current transmission capacity, thereby reducing the weight of the battery cell.

[0030] In some embodiments, the end portion of the wound main body further includes at least one liquid guiding region, and one of the liquid guiding regions is located between the adjacent first conductive region and the second conductive region along the radial direction of the wound main body for guiding the electrolyte to flow into the inside of the wound main body.

[0031] In this embodiment, a liquid guiding area is arranged between adjacent first conductive areas and second conductive areas, which can not only separate the first tab and the second tab spatially to play an insulating role, but also enable the electrolyte to infiltrate into the interior of the winding body from the liquid guiding area, ensuring the infiltration performance of the electrode assembly, improving the liquid absorption effect, so that during the charging and discharging process of the battery, the electrolyte can fully react with the active substances on the first electrode sheet and the second electrode sheet, thereby optimizing the performance of the battery cell.

[0032] In some embodiments, there are multiple liquid guiding areas. The end of the winding body has multiple first conductive areas arranged at intervals in the radial direction, and a liquid guiding area is arranged between adjacent first conductive areas; and / or the end of the winding body has multiple second conductive areas arranged at intervals in the radial direction, and a liquid guiding area is arranged between adjacent second conductive areas.

[0033] In this embodiment, by arranging multiple first conductive areas and / or second conductive areas at intervals in the radial direction, on the basis of ensuring the current-carrying capacity of the tabs, it is more conducive to improving the infiltration performance of the electrolyte. The electrolyte can enter the interior of the winding body through the liquid guiding areas between adjacent first conductive areas and second conductive areas, the liquid guiding areas between adjacent first conductive areas, and the liquid guiding areas between adjacent second conductive areas at the same time. During the charging and discharging process of the battery, the distribution of the electrolyte in the interior of the winding body along the radial direction is more uniform, so that the electrolyte can fully react with the active substances on the first electrode sheet and the second electrode sheet, thereby optimizing the performance of the battery cell.

[0034] In some embodiments, the electrode assembly further includes a separator for isolating the first electrode sheet and the second electrode sheet. The separator, the first main body part and the second main body part are wound to form a winding body; in the extending direction of the winding axis, the part of the separator located in the liquid guiding area extends beyond the sides of the first main body part and the second main body part.

[0035] In this embodiment, the separator is widened in the liquid guiding area, which can make the sides of the separator extend outwards between the first electrode sheet and the second electrode sheet in the liquid guiding area and be immersed in the electrolyte, so that the separator can more easily absorb the electrolyte under capillary action, improving the infiltration performance of the electrode assembly and further enhancing the performance of the battery cell.

[0036] In some embodiments, the battery cell further includes a first insulating member, and at least part of the first insulating member is arranged between adjacent first conductive areas and second conductive areas along the radial direction of the winding body.

[0037] This embodiment can separate the first tab and the second tab through the first insulating member to prevent the first tab and the second tab from contacting and short-circuiting when subjected to vibration or impact, improving the working reliability of the battery cell.

[0038] According to the second aspect of the present application, a battery is provided, including: the battery cell of the above embodiment and a box body for accommodating the battery cell.

[0039] According to a third aspect of the present application, there is provided an electrical device, including the battery of the above embodiment, and the battery is used to provide electrical energy for the electrical device.

[0040] According to a fourth aspect of the present application, there is provided a method for manufacturing a battery cell, including:

[0041] Component providing step: providing a housing, an end cap assembly, and first and second pole pieces with opposite polarities; wherein, the housing has an opening, the end cap assembly includes an end cap body and an electrode terminal provided on the end cap body, the first pole piece includes a first main body portion and a first pole tab protruding from the first main body portion, and the second pole piece includes a second main body portion and a second pole tab protruding from the second main body portion;

[0042] Pole piece winding step: winding the first and second pole pieces around a winding axis so that the first and second main body portions are superimposed to form a winding body, and one end of the winding body includes a first conductive region and a second conductive region; the first pole tab is led out in the first conductive region, the second pole tab is led out in the second conductive region, and the adjacent first and second conductive regions are spaced apart along the radial direction of the winding body;

[0043] End cap mounting step: closing the opening with the end cap assembly, and electrically connecting the first pole tab to the electrode terminal and the second pole tab to the end cap body.

[0044] According to a fifth aspect of the present application, there is provided a manufacturing device for a battery cell, including:

[0045] Component providing device, configured to provide a housing, an end cap assembly, and first and second pole pieces with opposite polarities; wherein, the housing has an opening, the end cap assembly includes an end cap body and an electrode terminal provided on the end cap body, the first pole piece includes a first main body portion and a first pole tab protruding from the first main body portion, and the second pole piece includes a second main body portion and a second pole tab protruding from the second main body portion;

[0046] Pole piece winding device, configured to wind the first and second pole pieces around a winding axis so that the first and second main body portions are superimposed to form a winding body, and one end of the winding body includes a first conductive region and a second conductive region; the first pole tab is led out in the first conductive region, the second pole tab is led out in the second conductive region, and the adjacent first and second conductive regions are spaced apart along the radial direction of the winding body; and an end cap mounting device, configured to close the opening with the end cap assembly, and electrically connect the first pole tab to the electrode terminal and the second pole tab to the end cap body. Description of the Drawings

[0047] To more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments of the present application. Obviously, the following described drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the drawings.

[0048] Figure 1 It is a schematic structural diagram of some embodiments of installing a battery in a vehicle in the present application.

[0049] Figure 2 It is an exploded view of some embodiments of the battery in the present application.

[0050] Figure 3 It is a schematic structural diagram of some embodiments of a battery cell in the present application.

[0051] Figure 4 It is an exploded view of some embodiments of the battery cell in the present application.

[0052] Figure 5 It is a schematic diagram of the end structure of some embodiments of an electrode assembly.

[0053] Figure 6 It is Figure 5 The developed view of the electrode assembly shown above.

[0054] Figure 7 It is a top view of some embodiments of the battery cell in the present application.

[0055] Figure 8 It is Figure 7 The A-A cross-sectional view of the first embodiment of the battery cell shown above.

[0056] Figure 9 It is Figure 7 The A-A cross-sectional view of the second embodiment of the battery cell shown above.

[0057] Figure 10 It is Figure 7 The A-A cross-sectional view of the third embodiment of the battery cell shown above.

[0058] Figure 11 It is Figure 7 The A-A cross-sectional view of the fourth embodiment of the battery cell shown above.

[0059] Figure 12 It is Figure 7 The A-A cross-sectional view of the fifth embodiment of the battery cell shown above.

[0060] Figure 13 It is a schematic diagram of the end structure of some other embodiments of an electrode assembly.

[0061] Figure 14Schematic flow diagram of some embodiments of the method for manufacturing battery cells of the present application.

[0062] Figure 15 Schematic diagram of the module composition of some embodiments of the battery cell manufacturing apparatus of the present application.

[0063] In the drawings, the drawings are not drawn to actual scale.

[0064] Marking description:

[0065] 10. Electrode assembly; 1. First electrode tab; 11. First main body portion; 12. First tab; 12'. First tab group; 2. Second electrode tab; 21. Second main body portion; 22. Second tab; 22'. Second tab group; 3. Separator; 111. Liquid conduction region; 112. First conductive region; 113. Second conductive region;

[0066] 100. Battery cell; 101. Housing; 1011. Opening; 1012. Recessed portion; 1013. Bent portion; 102. End cap assembly; 1021. End cap body; 1021'. Second groove; 1021A. Main body plate; 1021B. Protruding portion; 1021C. Through hole; 1022. Electrode terminal; 1022'. First groove; 1022A. First terminal portion; 1022B. Second terminal portion; 1022C. Second insulating member; 1023. Cover body; 1024. Pressure relief component; 103. Insulating film; 104. Adapter; 1041. First connection portion; 1042. Second connection portion; 105; First insulating ring; 106. Second insulating ring; 107. First insulating member; 108. Central tube; 109. Sealing member;

[0067] 200. Battery; 201. Box body; 201A. Accommodating portion; 201B. First cover body; 201C. Second cover body;

[0068] 300. Vehicle; 301. Axle; 302. Wheel; 303. Motor; 304. Controller;

[0069] 400. Manufacturing apparatus; 410. Component providing device; 420. Electrode tab winding device; 430. End cap mounting device;

[0070] ]>S. Winding main body; K. Winding axis; W1. First welding portion; W2. Second welding portion. Detailed implementation manners

[0071] The following further describes in detail the implementation manners of the present application in conjunction with the drawings and embodiments. The detailed description and drawings of the following embodiments are used to exemplarily illustrate the principle of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0072] In the description of the present application, it should be noted that unless otherwise specified, the meaning of "a plurality of" is more than two; the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "inner", "outer", etc. is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation on the present application.

[0073] In addition, terms such as "first", "second", "third", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. "Vertical" is not strictly vertical, but within the allowable error range. "Parallel" is not strictly parallel, but within the allowable error range. The orientation terms appearing in the following description are all the directions shown in the figures and do not limit the specific structure of the present application.

[0074] In the description of the present application, it should also be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0075] Referring to "embodiments" herein means that the specific features, structures, or characteristics described in connection with the embodiments can be included in at least some embodiments of the present application. The phrase appearing in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0076] In the description of the embodiments of the present application, the term "a plurality of" means more than two (including two). Similarly, "a plurality of groups" means more than two groups (including two groups), and "a plurality of pieces" means more than two pieces (including two pieces).

[0077] The present application uses the description of the orientation or positional relationship indicated by terms such as "upper", "lower", "top", "bottom", "front", "rear", "inner", and "outer", which is only for the convenience of describing the present application, rather than indicating or implying that the device referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation on the protection scope of the present application.

[0078] The battery cell may include a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery, a magnesium-ion battery, etc., and the embodiments of the present application are not limited thereto. The battery cell may be in a cylindrical shape, a flat shape, a cuboid shape or other shapes, etc., and the embodiments of the present application are also not limited thereto. Generally, the battery cells are divided into three types according to the encapsulation method: cylindrical battery cells, square battery cells and soft-pack battery cells, and the embodiments of the present application are also not limited thereto.

[0079] The current battery cell generally includes a housing and an electrode assembly accommodated in the housing, and an electrolyte is filled in the housing. The electrode assembly is mainly formed by laminating or winding a first pole piece and a second pole piece with opposite polarities, and a separator is usually provided between the first pole piece and the second pole piece. The parts of the first pole piece and the second pole piece coated with the active material constitute the main body of the electrode assembly, and the parts of the first pole piece and the second pole piece not coated with the active material respectively constitute a first pole ear and a second pole ear. In a lithium-ion battery, the first pole piece may be a positive electrode pole piece, including a positive electrode current collector and positive electrode active material layers provided on both sides of the positive electrode current collector. The material of the positive electrode current collector may be aluminum, for example, and the positive electrode active material may be lithium cobaltate, lithium iron phosphate, ternary lithium or lithium manganate, etc.; the second pole piece may be a negative electrode pole piece, including a negative electrode current collector and negative electrode active material layers provided on both sides of the negative electrode current collector. The material of the negative electrode current collector may be copper, for example, and the negative electrode active material may be graphite or silicon, etc. The first pole ear and the second pole ear may be located at one end of the main body together or at both ends of the main body respectively. During the charging and discharging process of the battery cell, the positive electrode active material and the negative electrode active material react with the electrolyte, and the pole ears are connected to the terminals to form a current loop.

[0080] The current battery cell is usually provided with a first electrode terminal and a second electrode terminal with opposite polarities for accessing an electrical circuit for power supply. The first pole ear is electrically connected to the first electrode terminal, and the second pole ear is electrically connected to the second electrode terminal. For example, for a cylindrical battery cell, since the area of the end of the battery cell is small, the second pole ear and the second electrode terminal are respectively provided at both ends of the battery cell. Correspondingly, the first pole ear and the second pole ear are respectively led out from both ends of the electrode assembly. The inventor found in practice that the pole ears and electrode terminals at each end will occupy a certain space for electrical connection, which requires more space in the height direction of the battery cell, resulting in an increase in the overall volume of the battery cell and affecting the overall energy density of the battery cell.

[0081] In order to improve the energy density of the battery cell, the inventor thought of arranging the first electrode terminal and the second electrode terminal on the same end of the battery cell. Correspondingly, the first pole ear and the second pole ear are led out from the same end of the electrode assembly. However, this setting method faces the following two problems.

[0082] 1. Space layout problem: When two electrode terminals are arranged on the end cap simultaneously, it will be rather crowded, and the insulation problem between the two electrode terminals also needs to be considered. In addition, a liquid injection hole and a pressure relief component need to be arranged on the end cap, and components such as a temperature acquisition component, a bus bar between battery cells, and various wires need to be arranged. It is difficult to carry out space layout when the area of the end cap is small.

[0083] 2. Insulation problem: The first electrode terminal and the second electrode terminal are arranged at the same end of the battery cell, and reliable insulation needs to be carried out. Moreover, when the first tab and the second tab are led out from the same end of the electrode assembly, the insulation problem also needs to be considered to improve the working reliability of the battery cell.

[0084] Based on the discovery of the above problems, the inventor of the present application improved the way of outputting electrical energy of the battery cell starting from the idea of improving the energy density of the battery cell and improving the space layout on the end cap.

[0085] The end cap assembly includes an end cap body and an electrode terminal, and the electrode terminal is insulated and connected to the end cap body; the end of the winding body of the electrode assembly includes a first conductive area and a second conductive area, the first tab is led out from the first conductive area, the second tab is led out from the second conductive area, and the adjacent first conductive area and second conductive area are arranged at intervals along the radial direction of the winding body; wherein, the first tab is electrically connected to the terminal, and the second tab is electrically connected to the end cap body. Such a battery cell can improve the overall energy density, simplify the structure and assembly process of the battery cell by eliminating one electrode terminal, and leave a large space on the end cap body, leaving sufficient space for arranging various components on the end cap.

[0086] The battery cell of the embodiment of the present application is applicable to batteries and electrical devices using the batteries.

[0087] The electrical device can be a mobile phone, a portable device, a laptop computer, a battery car, an electric vehicle, a ship, a spacecraft, an electric toy, an electric tool, etc. For example, the spacecraft includes an airplane, a rocket, a space shuttle, a spaceship, etc., the electric toy includes a fixed or mobile electric toy, for example, a game console, an electric vehicle toy, an electric ship toy, an electric airplane toy, etc., and the electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and a railway electric tool, for example, an electric drill, an electric grinding wheel, an electric wrench, an electric screwdriver, a hammer drill, an impact electric drill, a concrete vibrator, and a planer.

[0088] Such as Figure 1As shown, the electrical device may be a vehicle 300, such as a new energy vehicle, which can be a pure electric vehicle, a hybrid vehicle, an extended-range vehicle, etc.; or the electrical device may also be a drone or a ship, etc. Specifically, the vehicle 300 may include an axle 301, wheels 302 connected to the axle 301, a motor 303, a controller 304, and a battery 200. The motor 303 is used to drive the axle 301 to rotate, the controller 304 is used to control the operation of the motor 303, and the battery 200 can be arranged at the bottom, head, or tail of the vehicle 300 to provide electrical energy for the operation of the motor 303 and other components in the vehicle.

[0089] As Figure 2 shown, the battery 200 includes a box body 201 and battery cells 100. In the battery 200, the number of battery cells 100 can be one or more. If there are multiple battery cells 100, the multiple battery cells 100 can be connected in series, parallel, or in a combination of series and parallel. A combination of series and parallel means that there are both series and parallel connections among the multiple battery cells 100. It can be that multiple battery cells 100 are first connected in series, parallel, or in a combination of series and parallel to form battery modules, and then multiple battery modules are connected in series, parallel, or in a combination of series and parallel to form a whole and are accommodated in the box body 201. It can also be that all the battery cells 100 are directly connected in series, parallel, or in a combination of series and parallel together, and then the whole formed by all the battery cells 100 is accommodated in the box body 201.

[0090] The interior of the box body 201 is hollow and is used to accommodate one or more battery cells 100. According to the shape, quantity, combination method, and other requirements of the accommodated battery cells 100, the box body 201 can also have different shapes and sizes. For example, the box body 201 may include: a receiving portion 201A, a first cover body 201B, and a second cover body 201C. Both ends of the receiving portion 201A opposite to each other have openings, and the first cover body 201B and the second cover body 201C are respectively used to close the openings at both ends of the receiving portion 201A. Figure 2 Among them, according to the arrangement of the multiple battery cells 100, the receiving portion 201A has a rectangular cylindrical structure.

[0091] The battery cell 100 can be, for example, a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, or a magnesium-ion battery, etc.

[0092] In some embodiments, as Figure 3 and Figure 4 shown, the battery cell 100 includes: a housing 101, an end cap assembly 102, and an electrode assembly 10.

[0093] The housing 101 has an opening 1011, and the end cap assembly 102 is used to close the opening 1011. The end cap assembly 102 includes an end cap body 1021 and electrode terminals 1022 insulatedly connected to the end cap body 1021.

[0094] The electrode assembly 10 is disposed within the housing 101, as Figure 5 and Figure 6 shown. The electrode assembly 10 includes: a first pole piece 1 and a second pole piece 2 with opposite polarities. The first pole piece 1 includes a first main body portion 11 and a first pole tab 12 protruding from the first main body portion 11. The second pole piece 2 includes a second main body portion 21 and a second pole tab 22 protruding from the second main body portion 21. The first pole piece 1 and the second pole piece 2 are configured to be wound around a winding axis K such that the first main body portion 11 and the second main body portion 21 are superposed to form a wound body S. One end of the wound body S includes a first conductive region 112 and a second conductive region 113. The first pole tab 12 is led out at the first conductive region 112, and the second pole tab 22 is led out at the second conductive region 113. The adjacent first conductive region 112 and second conductive region 113 are spaced apart along the radial direction of the wound body S. Wherein, the first pole tab 12 is electrically connected to the electrode terminal 1022, and the second pole tab 22 is electrically connected to the end cap body 1021.

[0095] Wherein, the housing 101 has a hollow structure for accommodating the electrode assembly 10, and the housing 101 has an opening 1011. The end cap body 1021 is used to cover the opening 1011. For the cuboid battery cell 100, the end cap body 1021 has a rectangular plate-like structure; for the cylindrical battery cell 100, the end cap body 1021 has a disc-like structure.

[0096] There are two implementation forms for the insulating connection of the electrode terminal 1022 to the end cap body 1021. For example, an insulating layer is coated on the portion where the electrode terminal 1022 is connected to the end cap body 1021, or the electrode terminal 1022 includes a conductive portion and a second insulating member 1022C, and the second insulating member 1022C is disposed between the conductive portion and the end cap body 1021 to play an insulating role. Since the first pole tab 12 is electrically connected to the electrode terminal 1022 and the second pole tab 22 is electrically connected to the end cap body 1021, and the end cap body 1021 acts as an electrode terminal, insulatingly connecting the electrode terminal 1022 to the end cap body 1021 can achieve insulation of the positive and negative electrode terminals and improve the reliability of the operation of the battery cell 100. The "electrical connection" here includes both direct connection and indirect connection cases.

[0097] The electrode assembly 10 is formed by winding a first pole piece 1 and a second pole piece 2 with opposite polarities. The shapes of the first pole piece 1 and the second pole piece 2 are basically the same, and they can be strip-shaped belt structures. The wound body S formed can be a cylinder, a flat body, a cuboid or other shapes. Different active materials can be coated on the first main body portion 11 and the second main body portion 21. One first pole tab 12 can be provided, or multiple first pole tabs 12 can be provided at intervals along the winding direction. One second pole tab 22 can be provided, or multiple second pole tabs 22 can be provided along the winding direction. For example, the first pole piece 1 is a positive electrode piece and the second pole piece 2 is a negative electrode piece; or the first pole piece 1 is a negative electrode piece and the second pole piece 2 is a positive electrode piece.

[0098] At the end of the wound body S, the adjacent first conductive region 112 and the second conductive region 113 are arranged at intervals along the radial direction of the wound body S, so that the first pole tab 12 and the second pole tab 22 can be separated in space to avoid short circuit. Moreover, since no pole tab is provided in the radially spaced region, it can be used as a liquid guide region, and the electrolyte can infiltrate into the inside of the wound body S from the liquid guide region, so that the electrolyte can fully react with the active materials on the first pole piece 1 and the second pole piece 2 during the charge and discharge process of the battery.

[0099] To insulate the electrode assembly 10, an insulating film 103 can be provided between the wound body S and the housing 101; a first insulating ring 105 can be sleeved outside the second pole tab 22, and its height can be the same as the lead-out length of the second pole tab 22; a second insulating ring 106 can be provided between the end cap assembly 102 and the electrode assembly 10, and the second insulating ring 106 can be made of plastic.

[0100] In this embodiment, the first pole tab 12 and the second pole tab 22 are led out from the same end of the wound body S. Only an electrical connection space needs to be reserved at one end of the electrode assembly 10, and it also saves the need to provide electrode terminals 1022 at both ends of the battery cell 100, which can effectively improve the overall energy density of the battery cell 100. When the capacity of the battery cell 100 is certain, the volume of the battery cell 100 can be reduced, making it easier to layout the battery 200 in the electrical device.

[0101] Moreover, only one electrode terminal 1022 is provided for such a battery cell 100. The first pole tab 12 is electrically connected to the electrode terminal 1022, and the second pole tab 22 is directly electrically connected to the end cap body 1021, which can simplify the structure and assembly process of the battery cell 100. By omitting one electrode terminal, a larger space can be left on the end cap body 1021, which is easy to layout the liquid injection component and the pressure relief component on the end cap body 1021, and also leaves sufficient space for arranging the temperature acquisition component, the bus bar between battery cells 100 and various wires. It is also beneficial to increase the cross-sectional area of the electrode terminal 1022 to increase the over-current capacity of the battery cell 100. This design has greater advantages when the area of the end cap body 1021 is small.

[0102] In addition, the first tab 12 and the second tab 22 are arranged at a radial interval, which is beneficial to increasing the circumferential extension dimension of the first tab 12 and the second tab 22 along the winding body S, improving the connection strength between the tabs and the winding body S, enabling the tab roots to have a better self-supporting effect, reducing the wrinkling phenomenon of the tabs during the process of applying a circumferential force to flatten the tabs, making the shape of the flattened area stable, optimizing the electrical connection effect between the first tab 12 and the electrode terminal 1022, and between the second tab 22 and the end cap body 1021, ensuring that the electrode assembly 10 reliably transmits electrical energy outward, and improving the overcurrent capacity. Moreover, the radial interval area can not only separate the first tab 12 and the second tab 22 spatially to play an insulating role, but also enable the electrolyte to infiltrate into the interior of the winding body S from the radial interval area, ensuring the infiltration performance of the electrode assembly 13, improving the liquid absorption effect, so that during the charging and discharging process of the battery, the electrolyte can fully react with the active material, thereby optimizing the performance of the battery cell 100.

[0103] In some embodiments, as Figure 6 shown, the first conductive region 112 is located radially inside the second conductive region 113.

[0104] This embodiment enables the first tab 12 to be led out from the middle region of the winding body S, so that the electrode terminal 1022 is located at a position of the end cap body 1021 close to the middle region, leaving the surrounding area for arranging the liquid injection component and the pressure relief component, and also leaving sufficient space for arranging the temperature acquisition component, the bus bar between the battery cells 100, and various wires. It is also beneficial to increase the cross-sectional area of the electrode terminal 1022 to increase the overcurrent capacity of the battery cell 100. Optionally, the first conductive region 112 is located radially outside the second conductive region 113.

[0105] In some embodiments, the end of the winding body S further includes at least one liquid guiding region 111, and one of the liquid guiding regions 111 is located radially between the adjacent first conductive region 112 and the second conductive region 113 along the winding body S for guiding the electrolyte to flow into the interior of the winding body S.

[0106] No tab is provided in the liquid guiding region 111, and the gap between the first electrode sheet 1 or the second electrode sheet 2 and the separator 3 is communicated with the outside of the electrode assembly 10, so that the electrolyte can more easily enter the gap between the first electrode sheet 1 or the second electrode sheet 2 and the separator 3 and flow into the interior of the winding body S, and the separator 3 can also fully play the role of liquid absorption, so that during the charging and discharging process of the battery, the electrolyte can fully react with the active materials on the first electrode sheet 1 and the second electrode sheet 2.

[0107] In this embodiment, by providing a liquid guide area 111 between adjacent first conductive areas 112 and second conductive areas 113, it can not only spatially separate the first tab 12 and the second tab 22 to play an insulating role, but also enable the electrolyte to infiltrate into the interior of the winding body S from the liquid guide area 111, ensuring the infiltration performance of the electrode assembly 10 and improving the liquid absorption effect, so that during the charging and discharging process of the battery, the electrolyte can fully react with the active substances on the first electrode sheet 1 and the second electrode sheet 2, thereby optimizing the performance of the battery cell 100.

[0108] In some embodiments, there are multiple liquid guide areas 111. The end of the winding body S has multiple first conductive areas 112 arranged at intervals in the radial direction, and a liquid guide area 111 is provided between adjacent first conductive areas 112; and / or the end of the winding body S has multiple second conductive areas 113 arranged at intervals in the radial direction, and a liquid guide area 111 is provided between adjacent second conductive areas 113.

[0109] In this embodiment, by arranging multiple first conductive areas 112 and / or second conductive areas 113 at intervals in the radial direction, on the basis of ensuring the current-carrying capacity of the tabs, it is more conducive to improving the infiltration performance of the electrolyte. The electrolyte can enter the interior of the winding body S through the liquid guide area 111 between adjacent first conductive areas 112 and second conductive areas 113, the liquid guide area 111 between adjacent first conductive areas 112, and the liquid guide area 111 between adjacent second conductive areas 113 at the same time. During the charging and discharging process of the battery, the distribution of the electrolyte in the interior of the winding body S in the radial direction is more uniform, so that the electrolyte can fully react with the active substances on the first electrode sheet 1 and the second electrode sheet 2, thereby optimizing the performance of the battery cell 100.

[0110] In some embodiments, as Figure 6 shown, the electrode assembly 10 further includes a separator 3. The separator 3 is used to isolate the first electrode sheet 1 and the second electrode sheet 2. The separator 3, the first main body part 11 and the second main body part 21 are wound to form a winding body S; in the extending direction of the winding axis K, the part of the separator 3 located in the liquid guide area 111 extends beyond the sides of the first main body part 11 and the second main body part 21.

[0111] Among them, the separator 3 can be in a long strip-like structure in the unfolded state. The separator 3 can be made of PP (polypropylene) material or PE (polyethylene) material, and has micron-level or nano-level micropores inside, which are used for metal ions to pass through during the charging and discharging process of the battery.

[0112] Optionally, in the extending direction of the winding axis K, the part of one side of the separator 3 located in the liquid guide area 111 extends beyond the sides of the first main body part 11 and the second main body part 21; or the parts of both sides of the separator 3 located in the liquid guide area 111 extend beyond the sides of the first main body part 11 and the second main body part 21.

[0113] This embodiment widens the diaphragm 3 in the liquid-conducting area 111, so that the side of the diaphragm 3 can extend outward between the first electrode 1 and the second electrode 2 in the liquid-conducting area 111 and be immersed in the electrolyte, thereby making it easier for the diaphragm 3 to absorb the electrolyte under capillary action, thereby improving the wetting performance of the electrode assembly 10 and further improving the performance of the battery cell 100.

[0114] In some embodiments, as Figure 8 As shown, a first groove 1022' is provided on the surface of the electrode terminal 1022 away from the electrode assembly 10. The first groove 1022' is recessed toward the direction close to the electrode assembly 10. A first welding portion W1 is formed between the bottom surface of the first groove 1022' and the surface of the electrode terminal 1022 close to the electrode assembly 10. The first electrode tab 12 is welded to the first welding portion W1.

[0115] The shape and size of the first groove 1022' can be set according to the welding area. For example, the first tab 12 and the electrode terminal 1022 can be laser welded. The thickness of the first welding portion W1 should ensure that the welding energy can penetrate to achieve reliable fixation.

[0116] This embodiment reduces the thickness of the electrode terminal 1022 in the welding area by providing a first groove 1022' on the electrode terminal 1022. After the end cover assembly 102 is installed in the shell 101, welding can be performed directly from the outside of the electrode terminal 1022, thereby simplifying the assembly process and improving the firmness of the welding, so as to reliably achieve electrical connection between the electrode terminal 1022 and the first tab 12.

[0117] In some embodiments, as Figure 7 and Figure 8 As shown, a second groove 1021 ′ is provided on the side of the end cap body 1021 away from the electrode assembly 10 . The second groove 1021 ′ is radially located outside the electrode terminal 1022 . The second tab 22 is connected to a position on the end cap body 1021 corresponding to the second groove 1021 ′.

[0118] A second weld portion W2 is formed between the bottom surface of the second groove 1021' and the surface of the end cap body 1021 proximal to the electrode assembly 10. The second electrode tab 22 is welded to the second weld portion W2. The shape and size of the second groove 1021' can be customized to the welding area. For example, the second electrode tab 22 and the end cap body 1021 can be laser welded. The thickness of the second weld portion W2 should ensure that the welding energy can penetrate, ensuring reliable fixation.

[0119] Optionally, the end cap body 1021 includes a main body plate 1021A and a protruding portion 1021B. The protruding portion 1021B is connected to the side of the main body plate 1021A close to the electrode assembly 10, and the second groove 1021' extends into the protruding portion 1021B. The protruding portion 1021B locally thickens the main body plate 1021A on the side close to the electrode assembly 10, making the second welding portion W2 closer to the second tab 22 in the direction of the winding axis K, facilitating the direct single connection of the second tab 22 to the end cap body 1021 and eliminating the need for an adapter, simplifying the structure and reducing the lead-out length of the second tab 22. Moreover, when the main body plate 1021A is locally thickened, by extending the second groove 1021' into the protruding portion 1021B, the second welding portion W2 can also be maintained at an appropriate welding thickness, improving the reliability of the electrical connection.

[0120] In this embodiment, by providing the second groove 1021' on the end cap body 1021, the thickness of the end cap body 1021 in the welding area is reduced, enabling welding directly from the outside of the end cap body 1021 after the end cap assembly 102 is installed on the housing 101, simplifying the assembly process and improving the firmness of the welding to reliably achieve the electrical connection between the end cap body 1021 and the second tab 22.

[0121] Moreover, for the structure where the first conductive region 112 is located radially inside the second conductive region 113, the second groove 1021' is located radially outside the electrode terminal 1022, providing sufficient space to set the second groove 1021'. When the circumferential extension length of the second conductive region 113 is relatively long, it is beneficial to improve the reliability of the electrical connection between the second tab 22 and the end cap body 1021 by increasing the number or circumferential dimension of the second groove 1021'.

[0122] In some embodiments, as Figure 7 shown, a plurality of second grooves 1021' are provided, and the plurality of second grooves 1021' are circumferentially spaced along the circumference of the winding body S, and each second groove 1021' extends circumferentially.

[0123] For example, two second grooves 1021' are provided, and the two second grooves 1021' can be symmetrically arranged with respect to the winding axis K. The end cap assembly 102 may further include a liquid injection component and a pressure relief component 1024 provided on the end cap body 1021. The liquid injection component is provided between the first ends of the two second grooves 1021', and the pressure relief component 1024 is provided between the second ends of the two second grooves 1021'. Specifically, the liquid injection component may include a through hole 1021C provided on the end cap body 1021 and a cover body 1023. The through hole 1021C is used for injecting electrolyte, and after injecting the electrolyte, the cover body 1023 closes the through hole 1021C, and liquid injection can be performed after removing the cover body 1023. The pressure relief component 1024 is used for relieving pressure when the internal pressure of the housing 101 exceeds a preset threshold.

[0124] In this embodiment, a plurality of second grooves 1021' are circumferentially and spacedly arranged on the end cap body 1021, which can not only improve the reliability of the electrical connection between the second tab 22 and the end cap body 1021. For example, when welding is used to achieve the electrical connection, setting a plurality of welding positions can ensure the welding strength and prevent the welding positions from loosening when the battery 200 is vibrated and impacted during use. Moreover, other components such as a liquid injection component and a pressure relief component 1024 can be arranged between two adjacent second grooves 1021', making full use of the space on the end cap body 1021.

[0125] In some embodiments, as Figure 9 shown, the battery cell 100 further includes an adapter 104. The first tab 12 is electrically connected to the electrode terminal 1022 through the adapter 104, and / or the second tab 22 is electrically connected to the end cap body 1021 through the adapter 104. For example, welding or riveting can be used to achieve the electrical connection.

[0126] For example, when using the welding method, the first tab 12 and / or the second tab 22 can be welded to the adapter 104 first. After installing the end cap assembly 102, the electrode terminal 1022 is electrically connected to the adapter 104 from the outside of the end cap assembly 102, and the end cap body 1021 is electrically connected to the adapter 104.

[0127] For example, the adapter 104 includes a first connecting portion 1041 and a second connecting portion 1042 that are connected to each other. The dimension of the first connecting portion 1041 in the radial direction is larger than that of the second connecting portion 1042. For the adapter 104 connected between the first tab 12 and the electrode terminal 1022, the first connecting portion 1041 is electrically connected to the first tab 12, and the second connecting portion 1042 is electrically connected to the electrode terminal 1022; and / or for the adapter 104 connected between the second tab 22 and the end cap body 1021, the first connecting portion 1041 is electrically connected to the second tab 22, and the second connecting portion 1042 is connected to the end cap body 1021.

[0128] For example, the first connecting portion 1041 can adopt a disc-shaped structure, which can increase the connection area with the first tab 12 or the second tab 22 to improve the connection reliability. It is particularly suitable for the structure where the first tab 12 is wound at least one week, and the first tab 12 can be connected to the first connecting portion 1041 throughout the entire circumference. The second connecting portion 1042 can have a cylindrical structure. One end of the cylindrical structure can be connected to the first connecting portion 1041, for example, at the center position of the first connecting portion 1044, and the other end is connected to the electrode terminal 1022. Considering the small size of the electrode terminal 1022, the electrical connection between the first tab 12 and the electrode terminal 1022 through the adapter 104 can improve the reliability of power transmission.

[0129] By making the radial dimension of the first connecting portion 1041 larger than that of the second connecting portion 1042, the first connecting portion 1041 can cover more tab layers in the first tab 12 or the second tab 22 in the radial direction, increasing the connection length between the first connecting portion 1041 and the first tab 12 or the second tab 22 in the radial direction, and improving the electrical connection reliability. For example, when performing electrical connection by welding, the welding track can pass through more tab layers, making the connection between the first connecting portion 1041 and the tab more firm. Moreover, by reducing the radial dimension of the second connecting portion 1042, it can be adapted to the connection area with the electrode terminal 1022 or the end cap body 1021, so as to adapt to the smaller cross-sectional area of the electrode terminal 1022 and reduce the electrical connection area on the end cap body 1021, in order to leave space for arranging other components.

[0130] Optionally, the first tab 12 can also be directly electrically connected to the electrode terminal 1022, and the second tab 22 can also be directly electrically connected to the end cap body 1021. Whether the first tab 12 and the second tab 22 need to be provided with the adapter 104 can be determined according to the connection requirements.

[0131] In this embodiment, by providing the adapter 104, the requirements for the positional relationship between the first tab 12 and the electrode terminal 1022, and between the second tab 22 and the end cap body 1021 can be reduced, thereby reducing the process difficulty of electrical connection; moreover, since multiple tabs are relatively fluffy, it is easier to improve the connection reliability through the adapter 104 to increase the current-carrying capacity of the inner and outer ring tabs. For example, when performing electrical connection by welding, the welding track between the adapter 104 and the tab can be controlled to improve the firmness of welding; in addition, damage to the tab or the winding body S during electrical connection can also be prevented. For example, when welding, it can prevent the welding energy from burning the tab, deforming the winding body S, or causing the coating layer on the first main body portion 11 and the second main body portion 21 to fall off, etc.

[0132] In some embodiments, the first tab 12 winds at least one full turn, and / or the second tab 22 winds at least one full turn.

[0133] In this embodiment, the tab continuously extends and winds at least one turn, having better connection strength with the winding body S in the circumferential direction, enabling the tab root to have better self-supporting effect. During the process of applying a circumferential force to smooth the tab, it can prevent the tab from wrinkling, making the shape of the smoothed area stable, optimizing the welding effect between the first tab 12 and the electrode terminal 1022 and between the second tab 22 and the end cap body 1021, ensuring that the electrode assembly 10 reliably transmits electrical energy outward, and improving the current-carrying capacity. In addition, the particles generated during tab welding are not easily dropped between the first electrode plate 1 and the second electrode plate 2 in the liquid guide area 111 in the circumferential direction, which can improve the working reliability of the electrode assembly 10 and prevent problems such as short circuit or electrode plate scratching.

[0134] In addition, by providing continuous first tabs 12 on a partial winding length of the first main body portion 11 and continuous second tabs 22 on a partial winding length of the second main body portion 21, the current-carrying capacities of the first tabs 12 and the second tabs 22 can be satisfied. There is no need to provide discrete tabs over the entire winding length of the main body portion, which can simplify the process of die-cutting the tabbed electrode, and at the same time, when the first tabbed electrode 1 and the second tabbed electrode are wound to form a wound body S, there is no need to perform tab alignment either, which can simplify the process and improve the production efficiency of the electrode assembly 10.

[0135] In some embodiments, the first tab 12 winds multiple turns in the first conductive region 112, and / or the second tab 22 winds multiple turns in the second conductive region 113. The first tab 12 or the second tab 22 can wind at least two turns. For example, in order to achieve a better self-supporting effect of the first tab 12 or the second tab 22, the number of winding turns is at least 5 turns, and the number of winding turns can be designed according to the current-carrying capacity and polarization of the electrode assembly 10.

[0136] In this embodiment, by winding the tabs multiple turns in the conductive region, after being flattened, the bent portions of two adjacent tab layers in the tab overlap each other, further strengthening the supporting effect on the tabs, preventing the tabs from being flattened and wrinkled, making the shape of the bent portion stable, and optimizing the welding effect between the first tab 12 and the electrode terminal 1022 and between the second tab 22 and the end cap body 1021. Moreover, it can also increase the welding area between the flattened tab and the electrode terminal 1022 or the end cap body 1021, making the welding between the first tab 12 and the electrode terminal 1022 and between the second tab 22 and the end cap body 1021 more firm, ensuring that the electrode assembly 10 reliably transmits electrical energy outward and improving the current-carrying capacity.

[0137] In some embodiments, as Figure 10 shown, the battery cell 100 further includes a first insulating member 107, and at least a part of the first insulating member 107 is disposed radially along the wound body S between the adjacent first conductive region 112 and the second conductive region 113.

[0138] For example, the cross-section of the first insulating member 107 can be in an L-shaped structure. The horizontal portion of the L-shaped structure is connected to the end cap body 1021, and the vertical portion extends into the region between the first tab 12 and the second tab 22.

[0139] This embodiment can separate the first tab 12 and the second tab 22 through the first insulating member 107 to prevent the first tab 12 and the second tab 22 from contacting and short-circuiting due to vibration or impact, and improve the working reliability of the battery cell 100.

[0140] In some embodiments, as Figure 13As shown, a plurality of first tab ears 12 are arranged at intervals along the winding direction on the first pole piece 1. The plurality of first tab ears 12 form at least one first tab ear group 12'. There is at least one provided in the first conductive region 112. The first tab ear group 12' is arranged corresponding to the first conductive region 112. The first tab ear group 12' extends along a partial circumferential direction of the winding body S and includes a plurality of first tab ears 12 stacked in the radial direction. And / or a plurality of second tab ears 22 are arranged at intervals along the winding direction on the second pole piece 2. The plurality of second tab ears 22 form at least one second tab ear group 22'. There is at least one provided in the second conductive region 113. The second tab ear group 22' is arranged corresponding to the second conductive region 113. The second tab ear group 22' extends along a partial circumferential direction of the winding body S and includes a plurality of second tab ears 22 stacked in the radial direction.

[0141] For example, there are two first conductive regions 112. One first tab ear group 12' is led out from each of the two first conductive regions 112, and the two first conductive regions 112 are symmetrically arranged with respect to the winding axis K; there are two second conductive regions 113. One second tab ear group 22' is led out from each of the two second conductive regions 113, and the two second tab ear groups 22' are symmetrically arranged with respect to the winding axis K. The second conductive region 113 can be located radially outside the first conductive region 112.

[0142] The widths of the plurality of first tab ears 12 in the first tab ear group 12' are equal along the winding direction; and / or the widths of the plurality of second tab ears 22 in the second tab ear group 13' are equal along the winding direction. The tab ear group has a structure similar to a rectangle, except that the two opposite sides in the radial direction of the rectangle are arc-shaped. The same side ends of the plurality of tab ears in the tab ear group are aligned to increase the effective contact area when the tab ear group is electrically connected to the electrode terminal 1022 or the end cap body 1021, and improve the overcurrent capacity. This structure makes the widths of the plurality of tab ears in the tab ear group equal, which can reduce the difficulty of die-cutting the tab ears, is easy to ensure the size of the tab ears, and is easy to ensure the alignment degree of the plurality of tab ears during winding, thereby reducing the process difficulty of manufacturing the electrode assembly 10.

[0143] Optionally, the first tab ear group 12' and the second tab ear group 22' can also be in a fan-shaped structure.

[0144] Based on ensuring the current transmission capacity, the tab ear leading-out method in this embodiment can reduce the weight of the electrode assembly 10, thereby reducing the weight of the battery cell 100.

[0145] Figures 3 to 8 It is a schematic structural diagram of the first embodiment of the battery cell 100 of this application. As Figure 3 and Figure 4, the battery cell 100 includes a housing 101, an end cap assembly 102, and an electrode assembly 10. The housing 101 has an opening 1011, and the end cap assembly 102 is used to close the opening 1011. The end cap assembly 102 includes an end cap body 1021 and an electrode terminal 1022 insulatingly connected to the end cap body 1021. The end cap body 1021 is used to cover the opening 1011. For example, the battery cell 100 can be cylindrical.

[0146] The electrode assembly 10 is disposed within the housing 101, as Figure 5 shown, the electrode assembly 10 has a wound structure and includes a wound body S, a first tab 12 and a second tab 22 with opposite polarities. A ring-shaped liquid guiding area 111, a first conductive area 112, and a second conductive area 113 are concentrically provided at one end of the wound body S. The liquid guiding area 111 is radially located between the first conductive area 112 and the second conductive area 113. The first tab 12 extends from the first conductive area 112 and winds around at least one turn, and the second tab 22 extends from the second conductive area 113 and winds around at least one turn, for example, winds around 5 turns.

[0147] As Figure 6 shown, the first electrode tab 1 includes a first main body portion 11 and a first tab 12 protruding from the first main body portion 11. The second electrode tab 2 includes a second main body portion 21 and a second tab 22 protruding from the second main body portion 21. The first electrode tab 1, the second electrode tab 2, and the separator 3 are configured to be wound around a winding axis K so that the first main body portion 11, the second main body portion 21, and the separator 3 are stacked to form the wound body S. The first tab 12 and the second tab 22 are located at the same end of the wound body S along the winding axis, and the first tab 12 and the second tab 22 are located at the inner end and the outer end respectively along the winding direction. At least one side of the separator 3 located in the liquid guiding area 111 can extend beyond the first main body portion 11 and the second main body portion 21.

[0148] As Figure 7 and Figure 8 shown, the first tab 12 is electrically connected to the electrode terminal 1022, and the center line of the electrode terminal 1022 coincides with the winding axis K. The second tab 22 is electrically connected to the end cap body 1021.

[0149] The electrode terminal 1022 can be designed as a composite electrode terminal, which includes a first terminal portion 1022A, a second terminal portion 1022B, and a second insulating member 1022C. The first terminal portion 1022A and the second terminal portion 1022B are connected along the direction of the winding axis K. The second terminal portion 1022B is located between the first terminal portion 1022A and the electrode assembly 10. The second insulating member 1022C is sleeved outside the first terminal portion 1022A and the second terminal portion 1022B.

[0150] For example, the electrode terminal 1022 is a negative terminal. The first terminal portion 1022A is made of aluminum material and is used to connect to the external circuit of the battery cell 100. The second terminal portion 1022B is made of copper material and can be designed as a disc-shaped structure. The second terminal portion 1022B is directly electrically connected to the first tab 12, for example, by welding or other means. A through hole extending along the winding axis K is provided on the first terminal portion 1022A to form a first groove 1022' on the surface of the electrode terminal 1022 away from the electrode assembly 10, and a portion of the second terminal portion 1022B corresponding to the through hole is used as a first welding portion W1 to weld to the first tab 12.

[0151] A second groove 1021' is provided on the surface of the end cap body 1021 away from the electrode assembly 10. The second groove 1021' is recessed in the direction close to the electrode assembly 10. A second welding portion W2 is formed between the bottom surface of the second groove 1021' and the surface of the end cap body 1021 close to the electrode assembly 10. The second tab 22 is welded to the second welding portion W2. The end cap body 1021 includes a main body plate 1021A and a protruding portion 1021B. The protruding portion 1021B is connected to the side of the main body plate 1021A close to the electrode assembly 10. The second groove 1021' extends into the protruding portion 1021B. The protruding portion 1021B protrudes to abut against the second tab group 13, and the second welding portion W2 is directly welded to the second tab 22 through the second groove 1021', without the need to provide an adapter 104.

[0152] Since the distance between the electrode terminal 1022 and the end face of the winding body S is greater than the distance between the protruding portion 1021B and the end face of the winding body S, the extension length of the first tab 12 is greater than the extension length of the second tab 22.

[0153] The housing 101 has a recessed portion 1012. The recessed portion 1012 is recessed inward as a whole relative to the outer wall of the housing 11 in the circumferential direction. The housing 101 forms a bent portion 1013 at one end of the recessed portion 1012 close to the opening 1011. The bent portion 1013 has a receiving cavity. The outer end of the end cap body 1021 in the radial direction is embedded in the receiving cavity. The battery cell 100 further includes a seal 109, and the seal 109 is provided between the bent portion 1013 and the end cap body 1021.

[0154] Among them, the recessed portion 1012 can extend along the entire circumference of the housing 101, or a plurality of recessed portions 1012 can be arranged at intervals in the circumferential direction of the housing 101. The seal 109 can be an O-ring, and the cross-section of the O-ring can be in a C-shaped structure. The O-ring is sleeved on the outer end of the end cap body 1021 to insulate the end cap body 1021 from the housing 101. Optionally, an extension portion can be provided at one end of the C-shaped structure close to the electrode assembly 10, and the extension portion extends along the direction towards the electrode assembly 10 to insulate the recessed portion 1012 from the internal structure of the battery cell 10. For example, the seal 109 can be made of materials such as rubber.

[0155] Among them, when fixing the end cap assembly 102, first sleeve the seal 109 on the outer end of the end cap assembly 102 in the radial direction, and place the end cap assembly 102 into the housing 101 from the opening 1011. The end cap assembly 102 abuts against the recessed portion 1012, and then the housing 101 is bent at one end of the recessed portion 1012 close to the opening 1011 to form a bent portion 1013, and the bent portion 1013 wraps outside the seal 109. By adopting the caulking method to realize the fixation between the end cap assembly 102 and the housing 101 and setting the seal 109, the insulation between the end cap body 1021 and the housing 101 can be realized. In this way, when the end cap body 1021 is used as an electrode terminal, the housing 101 can be made non-electrified, improving the safety of the operation of the battery cell 100.

[0156] Figure 9 Schematic diagram of the second embodiment of the battery cell 100 of the present application, different from Figure 8 the first embodiment shown in that the lead-out lengths of the first tab 12 and the second tab 22 are the same, and the first tab 12 is electrically connected to the electrode terminal 1022 through an adapter 104. The adapter 104 includes: a first connecting portion 1041 and a second connecting portion 1042 connected to each other, and the dimension of the first connecting portion 1041 in the radial direction is larger than that of the second connecting portion 1042. For the adapter 104 connected between the first tab 12 and the electrode terminal 1022, the first connecting portion 1041 is electrically connected to the first tab 12, and the second connecting portion 1042 is electrically connected to the electrode terminal 1022.

[0157] Figure 10 Schematic diagram of the third embodiment of the battery cell 100 of the present application, different from Figure 9The difference of the second embodiment shown is that the battery cell 100 further includes a first insulating member 107 . At least a portion of the first insulating member 107 is disposed between the adjacent first conductive region 112 and second conductive region 113 along the radial direction of the wound body S, and a predetermined distance H is maintained between the first insulating member 107 and the end surface of the wound body S. For example, the first insulating member 107 may have an L-shaped cross-section, with the horizontal portion of the L-shaped structure connected to the end cap body 1021 and the vertical portion extending into the region between the first electrode tab 12 and the second electrode tab 22 and maintaining a predetermined distance H between the first insulating member 107 and the end surface of the wound body S.

[0158] Figure 11 This is a schematic diagram of a fourth embodiment of a battery cell 100 of the present application, and Figure 8 The difference from the first embodiment is that the second terminal portion 1022B is designed so that a local area of the plate-like structure protrudes toward the electrode assembly 10 to be connected to the first electrode tab 12 , thereby eliminating the need for the adapter 104 .

[0159] Figure 12 This is a schematic diagram of a fifth embodiment of a battery cell 100 of the present application, and Figure 9 The difference of the second embodiment shown is that a central tube 108 is provided in the hollow area of the winding body S located at the center of the winding, and one end of the central tube 108 is flush with the first tab 12 so that the central tube 108 can provide support when the adapter 104 is placed and welded to the first tab 12.

[0160] Secondly, the present application also provides a method for manufacturing a battery cell 100. In some embodiments, as Figure 14 As shown, the manufacturing method includes:

[0161] S110, component providing step: providing a housing 101, an end cap assembly 102, and a first electrode piece 1 and a second electrode piece 2 with opposite polarities; wherein the housing 101 has an opening 1011, the end cap assembly 102 includes an end cap body 1021 and an electrode terminal 1022 provided on the end cap body 1021, the first electrode piece 1 includes a first main body portion 11 and a first electrode tab 12 protruding from the first main body portion 11, and the second electrode piece 2 includes a second main body portion 21 and a second electrode tab 22 protruding from the second main body portion 21;

[0162] S120, pole piece winding step: winding the first pole piece 1 and the second pole piece 2 around the winding axis K so that the first main body portion 11 and the second main body portion 21 overlap to form a winding body S, wherein one end of the winding body S includes a first conductive area 112 and a second conductive area 113; the first pole tab 12 is led out of the first conductive area 112, and the second pole tab 22 is led out of the second conductive area 113, and adjacent first conductive areas 112 and second conductive areas 113 are spaced apart in the radial direction of the winding body S;

[0163] S130, End - cap installation step: Close the opening 1011 with the end - cap assembly 102, electrically connect the first tab 12 to the electrode terminal 1022, and electrically connect the second tab 22 to the end - cap body 1021.

[0164] Among them, S110 - S130 are executed in sequence.

[0165] In this embodiment, the first tab 12 and the second tab 22 are led out from the same end of the winding body S. Only the electrical connection space needs to be reserved at one end of the electrode assembly 10, and it also eliminates the need to separately arrange the electrode terminals 1022 at both ends of the battery cell 100. It can effectively improve the overall energy density of the battery cell 100. When the capacity of the battery cell 100 is certain, it can reduce the volume of the battery cell 100, making it easier to layout the battery 200 in the electrical device.

[0166] Moreover, this kind of battery cell 100 is only provided with one electrode terminal 1022, which can simplify the structure and assembly process of the battery cell 100. By eliminating one electrode terminal, a larger space can be left on the end - cap body 1021, which is conducive to arranging the liquid - injection component and the pressure - relief component 1024 on the end - cap body 1021, and also leaves sufficient space for arranging the temperature - acquisition component, the bus - bar between battery cells 100, and various wires. It is also beneficial to increase the cross - sectional area of the electrode terminal 1022 to increase the over - current capacity of the battery cell 100.

[0167] In addition, the first tab 12 and the second tab 22 are arranged at a radial interval, which is beneficial to increasing the circumferential extension dimension of the first tab 12 and the second tab 22 along the winding body S, improving the connection strength between the tab and the winding body S, enabling the root of the tab to have a better self - supporting effect, reducing the wrinkling phenomenon of the tab during the process of applying a circumferential force to flatten the tab, making the shape of the flattened area stable, optimizing the electrical connection effect between the first tab 12 and the electrode terminal 1022, and between the second tab 22 and the end - cap body 1021, ensuring that the electrode assembly 10 reliably transmits electrical energy outward, and improving the over - current capacity.

[0168] Finally, the present application also provides a manufacturing device 400 for the battery cell 100. In some embodiments, as Figure 15 shown, the manufacturing device 400 includes: a component - providing device 410, a pole - piece winding device 420, and an end - cap installation device 430.

[0169] The component providing device 410 is configured to provide a housing 101, an end cover assembly 102, and a first pole piece 1 and a second pole piece 2 with opposite polarities; wherein, the housing 101 has an opening 1011, the end cover assembly 102 includes an end cover body 1021 and an electrode terminal 1022 provided on the end cover body 1021, the first pole piece 1 includes a first main body portion 11 and a first pole tab 12 protruding from the first main body portion 11, and the second pole piece 2 includes a second main body portion 21 and a second pole tab 22 protruding from the second main body portion 21.

[0170] The pole piece winding device 420 is configured to wind the first pole piece 1 and the second pole piece 2 around a winding axis K so that the first main body portion 11 and the second main body portion 21 are superimposed to form a winding body S, and one end of the winding body S includes a first conductive region 112 and a second conductive region 113; the first pole tab 12 is led out in the first conductive region 112, the second pole tab 22 is led out in the second conductive region 113, and the adjacent first conductive region 112 and second conductive region 113 are arranged at intervals along the radial direction of the winding body S.

[0171] The end cover mounting device 430 is configured to close the opening 1011 with the end cover assembly 102, and electrically connect the first pole tab 12 with the electrode terminal 1022 and the second pole tab 22 with the end cover body 1021.

[0172] Although the present application has been described with reference to the preferred embodiments, various improvements can be made to it and components therein can be replaced with equivalents without departing from the scope of the present application. In particular, as long as there is no structural conflict, the technical features 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 (100), comprising: A housing (101) having an opening (1011); An end cap assembly (102) for closing the opening (1011), the end cap assembly (102) including an end cap body (1021) and an electrode terminal (1022) provided on the end cap body (1021); And An electrode assembly (10) provided in the housing (101) and including: a first pole piece (1) and a second pole piece (2) with opposite polarities, the first pole piece (1) including a first main body portion (11) and a first pole tab (12) protruding from the first main body portion (11), the second pole piece (2) including a second main body portion (21) and a second pole tab (22) protruding from the second main body portion (21), the first pole piece (1) and the second pole piece (2) being configured to be wound around a winding axis (K) such that the first main body portion (11) and the second main body portion (21) are superposed to form a wound body (S); one end of the wound body (S) includes a first conductive region (112) and a second conductive region (113), the first pole tab (12) is led out in the first conductive region (112), the second pole tab (22) is led out in the second conductive region (113), and the adjacent first conductive region (112) and second conductive region (113) are arranged at intervals in the radial direction of the wound body (S); Wherein, the first pole tab (12) is electrically connected to the electrode terminal (1022), and the second pole tab (22) is electrically connected to the end cap body (1021).

2. The battery cell (100) according to claim 1, wherein, The first conductive region (112) is located radially inside the second conductive region (113).

3. The battery cell (100) according to claim 1, wherein, A first groove (1022') is provided on the surface of the electrode terminal (1022) away from the electrode assembly (10), the first groove (1022') is recessed in the direction close to the electrode assembly (10), and a first welding portion (W1) is formed between the bottom surface of the first groove (1022') and the surface of the electrode terminal (1022) close to the electrode assembly (10), and the first pole tab (12) is welded to the first welding portion (W1).

4. The battery cell (100) according to claim 1, wherein, A second groove (1021') is provided on the surface of the end cap body (1021) away from the electrode assembly (10), the second groove (1021') is recessed in the direction close to the electrode assembly (10), and a second welding portion (W2) is formed between the bottom surface of the second groove (1021') and the surface of the end cap body (1021) close to the electrode assembly (10), and the second pole tab (22) is welded to the second welding portion (W2).

5. The battery cell (100) according to claim 4, wherein, There are a plurality of the second grooves (1021'), and the plurality of second grooves (1021') are arranged at intervals in the circumferential direction of the wound body (S).

6. The battery cell (100) according to claim 1 further includes an adapter (104), the first tab (12) is electrically connected to the electrode terminal (1022) through the adapter (104), and / or the second tab (22) is electrically connected to the end cap body (1021) through the adapter (104).

7. The battery cell (100) according to claim 1, wherein, The first tab (12) winds at least one full turn, and / or the second tab (22) winds at least one full turn.

8. The battery cell (100) according to claim 1, wherein, The first tab (12) winds multiple turns in the first conductive region (112), and / or the second tab (22) winds multiple turns in the second conductive region (113).

9. The battery cell (100) according to claim 1, wherein, A plurality of the first tabs (12) are arranged at intervals along the winding direction on the first electrode sheet (1), and the plurality of first tabs (12) form at least one first tab group (12'), at least one of the first tab groups (12') is provided in the first conductive region (112), the first tab group (12') is arranged corresponding to the first conductive region (112), the first tab group (12') extends along a partial circumference of the winding body (S), and includes a plurality of the first tabs (12) stacked in the radial direction; and / or A plurality of the second tabs (22) are arranged at intervals along the winding direction on the second electrode sheet (2), and the plurality of second tabs (22) form at least one second tab group (22'), at least one of the second tab groups (22') is provided in the second conductive region (113), the second tab group (22') is arranged corresponding to the second conductive region (113), the second tab group (22') extends along a partial circumference of the winding body (S), and includes a plurality of the second tabs (22) stacked in the radial direction.

10. The battery cell (100) according to claim 1, wherein, An end of the winding body (S) further includes at least one liquid guiding region (111), and one of the liquid guiding regions (111) is located between the adjacent first conductive region (112) and the second conductive region (113) along the radial direction of the winding body (S) for guiding electrolyte to flow into the interior of the winding body (S).

11. The battery cell (100) according to claim 10, wherein, A plurality of the liquid guiding regions (111) are provided. The end of the winding body (S) has a plurality of the first conductive regions (112) arranged at intervals in the radial direction, and the liquid guiding region (111) is provided between adjacent first conductive regions (112); and / or The end of the winding body (S) has a plurality of the second conductive regions (113) arranged at intervals in the radial direction, and the liquid guiding region (111) is provided between adjacent second conductive regions (113).

12. The battery cell (100) according to claim 10, wherein, The electrode assembly (10) further includes a separator (3), the separator (3) is used to isolate the first electrode sheet (1) and the second electrode sheet (2), and the separator (3), the first main body portion (11) and the second main body portion (21) are wound to form the winding body (S); In the extending direction of the winding axis (K), a portion of the separator (3) located in the liquid guiding region (111) extends beyond the sides of the first main body portion (11) and the second main body portion (21).

13. The battery cell (100) according to any one of claims 1 to 12 further includes a first insulating member (107), and at least a part of the first insulating member (107) is disposed in the radial direction of the winding body (S) between the adjacent first conductive region (112) and second conductive region (113).

14. A battery (200) includes: The battery cell (100) according to any one of claims 1 to 13; and a housing (201) for accommodating the battery cell (100).

15. An electrical device includes the battery (200) according to claim 14, and the battery (200) is configured to supply electrical energy to the electrical device.

16. A method for manufacturing a battery cell (100) includes: Component providing step: providing a housing (101), an end cap assembly (102), and first and second pole pieces (1) and (2) with opposite polarities; wherein, the housing (101) has an opening (1011), the end cap assembly (102) includes an end cap body (1021) and an electrode terminal (1022) disposed on the end cap body (1021), the first pole piece (1) includes a first main body portion (11) and a first pole tab (12) protruding from the first main body portion (11), and the second pole piece (2) includes a second main body portion (21) and a second pole tab (22) protruding from the second main body portion (21); Pole piece winding step: winding the first pole piece (1) and the second pole piece (2) around a winding axis (K) so that the first main body portion (11) and the second main body portion (21) are superposed to form a winding body (S), one end of the winding body (S) includes a first conductive region (112) and a second conductive region (113); the first pole tab (12) is led out in the first conductive region (112), the second pole tab (22) is led out in the second conductive region (113), and the adjacent first conductive region (112) and second conductive region (113) are spaced apart in the radial direction of the winding body (S); End cap mounting step: closing the opening (1011) with the end cap assembly (102), and electrically connecting the first pole tab (12) to the electrode terminal (1022) and the second pole tab (22) to the end cap body (1021).

17. A manufacturing apparatus (400) for a battery cell (100) includes: Component providing device (410), configured to provide a housing (101), an end cap assembly (102), and first and second pole pieces (1) and (2) with opposite polarities; wherein, the housing (101) has an opening (1011), the end cap assembly (102) includes an end cap body (1021) and an electrode terminal (1022) provided on the end cap body (1021), the first pole piece (1) includes a first main body portion (11) and a first pole tab (12) protruding from the first main body portion (11), and the second pole piece (2) includes a second main body portion (21) and a second pole tab (22) protruding from the second main body portion (21); Pole piece winding device (420), configured to wind the first pole piece (1) and the second pole piece (2) around a winding axis (K) such that the first main body portion (11) and the second main body portion (21) are superimposed to form a winding body (S), one end of the winding body (S) includes a first conductive region (112) and a second conductive region (113); the first pole tab (12) is led out in the first conductive region (112), the second pole tab (22) is led out in the second conductive region (113), and the adjacent first conductive region (112) and second conductive region (113) are arranged at intervals along the radial direction of the winding body (S); and End cap mounting device (430), configured to close the opening (1011) with the end cap assembly (102), and electrically connect the first pole tab (12) to the electrode terminal (1022), and electrically connect the second pole tab (22) to the end cap body (1021).

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