Battery monomer, battery device and power utilization device

Abstract

The embodiment of the invention provides a battery monomer, a battery device and a power utilization device, and belongs to the technical field of batteries. A battery cell includes a housing, a first electrode terminal, and an electrode assembly. The shell is provided with a containing cavity, the first electrode terminal is fixed to the first wall of the shell, the electrode assembly assembly comprises a first electrode assembly located in the containing cavity, the first electrode assembly comprises at least two layers of first pole pieces and at least two layers of first isolation pieces, and the first pole pieces and the first isolation pieces are arranged in a stacked and staggered mode and jointly form a winding structure. The extension direction of a winding shaft of the winding structure is the first direction, the first electrode assembly comprises a first body and a first tab, the length of the first body in the first direction is larger than that of the first body in the direction perpendicular to the first direction, and the first tab protrudes from the first body towards the side close to the first wall in the first direction. The second electrode is electrically connected to the first electrode terminal. The battery monomer provided by the invention is beneficial to reducing the possibility of damage of the electrode assembly.

Description

Technical Field

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

[0002] Batteries are being used more and more widely in daily life and industry. For example, new energy vehicles equipped with batteries are already in widespread use.

[0003] In battery-powered new energy vehicles, the battery can provide all or part of the power. In related technologies, the electrode assembly of the battery cell is located inside the casing, and the electrode assembly may be damaged. Summary of the Invention

[0004] In view of this, embodiments of this application aim to provide a battery cell, a battery device, and an electrical device to reduce the possibility of damage to the electrode assembly of the battery cell.

[0005] To achieve the above objectives, the technical solution of this application embodiment is implemented as follows:

[0006] The first aspect of this application provides a battery cell, comprising:

[0007] A housing having a receiving cavity, the housing including a first wall;

[0008] The first electrode terminal is fixed to the first wall;

[0009] An electrode assembly includes a first electrode assembly housed in the receiving cavity. The first electrode assembly includes at least two layers of first electrode sheets and at least two layers of first spacers. The first electrode sheets and the first spacers are stacked and together form a winding structure. The first electrode sheets and the first spacers are staggered in the stacking direction of the winding structure. The winding axis of the winding structure extends in a first direction. The first electrode assembly includes a first body and a first tab. The length of the first body in the first direction is greater than the length of the first body in the direction perpendicular to the first direction. The first tab protrudes from the first body along the first direction toward a side close to the first wall and is electrically connected to the first electrode terminal.

[0010] In this embodiment, the length of the first body in the first direction is greater than the length of the first body in the direction perpendicular to the first direction, so that the first electrode sheet of this application can be manufactured without cutting the uncut roll of the first electrode sheet along... Figure 2The dashed line cut shown reduces the number of cut edges on the first electrode, and the burrs corresponding to the cut edge on the first electrode are also reduced accordingly. This reduces the possibility that the first separator, which is stacked with the first electrode, may be punctured by the burrs on the cut edge of the first electrode, causing insulation failure, thereby reducing the possibility of damage to the electrode assembly of the battery cell.

[0011] In some embodiments, the length of the first body in the first direction ranges from 225 mm to 1000 mm, and the maximum length of the first body in the perpendicular direction of the first direction ranges from 80 mm to 130 mm.

[0012] In this embodiment, the length of the first body in the first direction ranges from 225mm to 1000mm, and the maximum length of the first body in the vertical direction of the first direction ranges from 80mm to 130mm. On the one hand, the longer size of the first body in the first direction results in fewer first electrode components inside the housing in the first direction, which helps to reduce the space occupied by the first tabs between two adjacent first electrode components, thereby improving the energy density of the battery cell. On the other hand, the larger size of the first body in the first direction than the larger size of the first body in the vertical direction of the first direction eliminates the need to cut the uncut roll of first electrode sheets along the... Figure 2 The dashed line cut shown reduces the number of cut edges on the first electrode, and the burrs corresponding to the cut edge on the first electrode are also reduced accordingly. This reduces the possibility that the first separator, which is stacked with the first electrode, may be punctured by the burrs on the cut edge of the first electrode, causing insulation failure, thereby reducing the possibility of damage to the electrode assembly of the battery cell.

[0013] In some embodiments, the length of the first body in the first direction ranges from 500mm to 900mm, and the length of the first body in the direction perpendicular to the first direction ranges from 90mm to 120mm.

[0014] In this embodiment, the length of the first body in the first direction ranges from 500mm to 900mm, and the maximum length of the first body in the vertical direction of the first direction ranges from 90mm to 120mm. On the one hand, by further limiting the dimensions of the first body in the first direction and the dimensions in the vertical direction of the first direction, the longer dimension of the first body in the first direction results in fewer first electrode components inside the housing in the first direction, which helps to reduce the space occupied by the first tabs between two adjacent first electrode components, thereby helping to improve the energy density of the battery cell. On the other hand, the larger dimension of the first body in the first direction than the larger dimension of the first body in the vertical direction of the first direction eliminates the need to cut the uncut roll of first electrode sheets along the... Figure 2The dashed line cut shown reduces the number of cut edges on the first electrode, and the burrs corresponding to the cut edge on the first electrode are also reduced accordingly. This reduces the possibility that the first separator, which is stacked with the first electrode, may be punctured by the burrs on the cut edge of the first electrode, causing insulation failure, thereby reducing the possibility of damage to the electrode assembly of the battery cell.

[0015] In some embodiments, the ratio of the length of the first body in the first direction to the maximum length of the first body in the direction perpendicular to the first direction ranges from 1.5 to 13.

[0016] In this embodiment, the ratio of the length of the first body in the first direction to the maximum length of the first body in the perpendicular direction of the first direction ranges from 1.5 to 13, such that the size of the first body in the first direction is larger than the size of the first body in the perpendicular direction of the first direction, which eliminates the need to cut the entire roll of the first electrode sheet along the direction. Figure 2 The dashed line cut shown reduces the number of cut edges on the first electrode, and the burrs corresponding to the cut edge on the first electrode are also reduced accordingly. This reduces the possibility that the first separator, which is stacked with the first electrode, may be punctured by the burrs on the cut edge of the first electrode, causing insulation failure, thereby reducing the possibility of damage to the electrode assembly of the battery cell.

[0017] In some embodiments, the ratio of the length of the first body in the first direction to the maximum length of the first body in the direction perpendicular to the first direction ranges from 4 to 10.

[0018] In this embodiment, the ratio of the length of the first body in the first direction to the maximum length of the first body in the perpendicular direction of the first direction ranges from 4 to 10, such that the size of the first body in the first direction is larger than the size of the first body in the perpendicular direction of the first direction, which eliminates the need to cut the entire roll of the first electrode sheet along the direction. Figure 2 The dashed line cut shown reduces the number of cut edges on the first electrode, and the burrs corresponding to the cut edge on the first electrode are also reduced accordingly. This reduces the possibility that the first separator, which is stacked with the first electrode, may be punctured by the burrs on the cut edge of the first electrode, causing insulation failure, thereby reducing the possibility of damage to the electrode assembly of the battery cell.

[0019] In some embodiments, the housing includes a second wall, and the battery cell further includes a second electrode terminal mounted on the second wall. The first wall is located at one end of the housing along the first direction, and the second wall is located at the other end of the housing along the first direction. The electrode assembly further includes a second tab, which is located at one end of the electrode assembly along the first direction away from the first tab and electrically connected to the second electrode terminal. The first tab with positive polarity and the first tab with negative polarity are respectively electrically connected to the corresponding first electrode terminal, and the second tab with positive polarity and the second tab with negative polarity are respectively electrically connected to the corresponding second electrode terminal.

[0020] In this embodiment, the first wall and the second wall are located at opposite ends of the outer casing along a first direction. The first wall is fitted with a first electrode terminal, and the second wall is fitted with a second electrode terminal. A positively polarized first electrode tab and a negatively polarized first electrode tab are electrically connected to their respective first electrode terminals. Similarly, a positively polarized second electrode tab and a negatively polarized second electrode tab are electrically connected to their respective second electrode terminals. This ensures that each end of the battery cell along the first direction can form its own current loop, preventing the current from flowing from one end to the other along the first direction. This promotes more uniform heating of the battery cell in the first direction. The shorter distance the current travels within the battery cell also reduces the heat generated during normal operation, thus improving the safety of the battery cell.

[0021] In some embodiments, the housing includes a second wall, and the battery cell further includes a second electrode terminal mounted on the second wall. The first wall is located at one end of the housing along the first direction, and the second wall is located at the other end of the housing along the first direction. The electrode assembly further includes a second tab, which is located at one end of the electrode assembly along the first direction away from the first tab and electrically connected to the second electrode terminal. The dimension of the housing along the first direction is a first dimension. The maximum dimension of the first electrode terminal protruding from the first wall along the first direction is a second dimension. The maximum dimension of the second electrode terminal protruding from the second wall along the first direction is a third dimension. The ratio of the sum of the second dimension and the third dimension to the first dimension is a first ratio, which is greater than 0 and less than or equal to 0.02.

[0022] In this embodiment, the first ratio is greater than 0, causing the first electrode terminal and the second electrode terminal to protrude from the outer casing along the first direction, which facilitates the connection of the battery cell with adjacent battery cells or electrical devices. When the first ratio is less than or equal to 0.02, and the dimensions of the first electrode terminal and the second electrode terminal remain unchanged in the first direction, it is beneficial to balance the relationship between the energy density and safety of the battery cell, so that the battery cell can have a certain degree of safety while having a high energy density.

[0023] In some embodiments, the first ratio is greater than or equal to 0.008, and the first ratio is less than or equal to 0.015.

[0024] In this embodiment, the first ratio is greater than or equal to 0.008, which causes the first electrode terminal and the second electrode terminal to protrude from the outer casing along the first direction, facilitating the connection of the battery cell with adjacent battery cells or electrical devices. When the first ratio is less than or equal to 0.015, and the dimensions of the first electrode terminal and the second electrode terminal remain unchanged in the first direction, it is beneficial to balance the relationship between the energy density and safety of the battery cell, so that the battery cell can have a certain degree of safety while having a high energy density.

[0025] In some embodiments, the housing includes a second wall, the battery cell further includes a second electrode terminal mounted on the second wall, the first wall is located at one end of the housing along the first direction, the second wall is located at the other end of the housing along the first direction, the electrode assembly further includes a second tab, the second tab is located at one end of the electrode assembly along the first direction away from the first tab and electrically connected to the second electrode terminal, the electrode assembly includes only one first electrode assembly, the dimension of the housing along the first direction is a first dimension, the dimension of the first body along the first direction is a fourth dimension, the ratio of the fourth dimension to the first dimension is a second ratio, the second ratio is greater than or equal to 0.96, and the second ratio is less than or equal to 0.99.

[0026] In this embodiment, the second ratio is greater than or equal to 0.96, which allows the electrode assembly to make full use of the space inside the housing, thereby increasing the space ratio of the electrode assembly inside the housing and thus improving the energy density of the battery cell; the second ratio is less than or equal to 0.99, which allows the housing to have a certain amount of spare space to accommodate the gas inside the housing, thereby improving the safety of the battery cell.

[0027] In some embodiments, the second ratio is greater than or equal to 0.97, and the second ratio is less than or equal to 0.99.

[0028] In this embodiment, the second ratio is greater than or equal to 0.97, which allows the electrode assembly to make full use of the space inside the casing, thereby increasing the space ratio of the electrode assembly inside the casing and thus improving the energy density of the battery cell; the second ratio is less than or equal to 0.99, which allows the casing to have a certain amount of spare space to accommodate the gas inside the casing, thereby improving the safety of the battery cell.

[0029] In some embodiments, the first wall is located at one end of the housing along the first direction, the size of the housing along the first direction is a first dimension, the maximum size of the first electrode terminal protruding from the first wall along the first direction is a second dimension, the ratio of the second dimension to the first dimension is a third ratio, the third ratio is greater than or equal to 0, and the third ratio is less than or equal to 0.01.

[0030] In this embodiment, the third ratio is greater than 0, which causes the first electrode terminal to protrude from the outer casing along the first direction, making it easier for the battery cell to connect with adjacent battery cells or electrical devices. When the third ratio is less than or equal to 0.01, the first electrode terminal remains unchanged in the first direction, which helps to balance the relationship between the energy density and safety of the battery cell, so that the battery cell can have a certain degree of safety while having a high energy density.

[0031] In some embodiments, the first wall is located at one end of the housing along the first direction, the electrode assembly includes only one first electrode assembly, the size of the housing along the first direction is a first dimension, the size of the first body along the first direction is a fourth dimension, the ratio of the fourth dimension to the first dimension is a second ratio, the second ratio is greater than or equal to 0.98, and the second ratio is less than or equal to 0.99.

[0032] In this embodiment, the second ratio is greater than or equal to 0.98, which allows the electrode assembly to make full use of the space inside the housing, thereby increasing the space ratio of the electrode assembly inside the housing and thus improving the energy density of the battery cell; the second ratio is less than or equal to 0.99, which allows the housing to have a certain amount of spare space to accommodate the gas inside the housing, thereby improving the safety of the battery cell.

[0033] In some embodiments, the electrode assembly further includes a second electrode assembly, which includes at least two layers of second electrode sheets and at least two layers of second spacers. The second electrode sheets and the second spacers are stacked and together form a wound structure. The second electrode sheets and the second spacers are staggered in the stacking direction of the wound structure. The second electrode assembly includes a second body and a third electrode tab. The third electrode tab protrudes from the second body along the first direction toward a side close to the first wall. The outer shell includes a second wall arranged opposite to the first wall along the first direction. The first electrode assembly further includes a fourth electrode tab. The fourth electrode tab protrudes from the first body along the first direction toward a side close to the second wall. The first electrode sheet has a first sub-electrode tab. The fourth electrode tab is an electrode tab cluster formed by a plurality of first sub-electrode tabs. The second electrode sheet has a second sub-electrode tab. The third electrode tab is an electrode tab cluster formed by a plurality of second sub-electrode tabs.

[0034] The first electrode assembly and the second electrode assembly are arranged along the first direction, and the third electrode tab and the fourth electrode tab are arranged opposite to each other and electrically connected.

[0035] In this embodiment, the third and fourth tabs are arranged opposite to each other and electrically connected, allowing for direct connection between them without the need for adapter plates. This eliminates some mechanical structural components in the battery cell, resulting in lower costs. Furthermore, the tab clusters between adjacent first and second electrode assemblies are directly connected, and the strength of the tab clusters is essentially the same. This ensures good connection between the first and second electrode assemblies, thus alleviating the connection issues between them.

[0036] In some embodiments, the fourth electrode tab includes a first root portion near the first body and a first connecting portion away from the first body, the first connecting portion being in a constricted state, and located on one side of the winding shaft along a second direction; the third electrode tab includes a second root portion near the second body and a second connecting portion away from the second body, the second connecting portion being in a constricted state, and located on the other side of the winding shaft along a second direction; the first electrode includes a planar region and an arc-shaped corner region connected to each other, the second direction being parallel to the stacking direction of the first electrode in the planar region.

[0037] In this embodiment, the fourth tab includes a first connecting portion in a converged state, and the third tab includes a second connecting portion in a converged state. The convergence of the tab cluster to form the connecting portion increases the local strength of the tab cluster and alleviates deformation. Furthermore, the first connecting portion is located on one side of the first body along the first direction, and the second connecting portion is located on the other side of the second body along the first direction. This allows for a larger contact area between adjacent first and second electrode assemblies, resulting in higher connection strength. Moreover, the first and second electrode assemblies do not require offset or only require a small offset during welding, reducing the positioning difficulty between adjacent first and second electrode assemblies during welding and lowering the processing difficulty of the battery cell.

[0038] In some embodiments, along the second direction, all the first sub-taps of the fourth electrode tab are located on one side of the winding shaft, and all the second sub-taps of the third electrode tab are located on the other side of the winding shaft.

[0039] In this embodiment, all the first sub-tabs in the fourth tab are located on one side of the winding shaft, and all the second sub-tabs in the third tab are located on the other side of the winding shaft. The fourth tab can extend a longer distance toward the second electrode assembly along the first direction, thereby shortening the length occupied by the fourth tab and the third tab after welding, so that the first body and the second body can be arranged with a longer length along the first direction, thereby increasing the energy density of the battery cell.

[0040] In some embodiments, along the second direction, the first root portion and / or the second root portion spans across opposite sides of the corresponding winding shaft.

[0041] In this embodiment, the first root and / or the second root are positioned across the opposite sides of the corresponding winding shaft. The larger size of the electrode root along the second direction can alleviate the situation where the opposite electrode clusters are inserted into the electrode body, thus causing a short circuit.

[0042] In some embodiments, the fourth electrode tab includes a first root portion near the first body and a first connecting portion away from the first body, the first connecting portion being in a constricted state, and along a second direction, the first connecting portion being located on one side of the winding shaft; the third electrode tab includes a second root portion near the second body and a second connecting portion away from the second body, the second connecting portion being in a constricted state, and along a second direction, the first connecting portion and the second connecting portion being located on the same side of the winding shaft; the first electrode includes a planar region and an arc-shaped corner region connected to each other, the second direction being parallel to the stacking direction of the first electrode in the planar region.

[0043] In this embodiment of the application, along the second direction, the first connecting part and the second connecting part are located on the same side of the winding shaft. Both the first connecting part and the second connecting part can alleviate the situation where the opposite electrode tabs are inserted into the electrode body, thereby causing a short circuit.

[0044] In some embodiments, the lengths of the third and fourth electrodes are both less than or equal to the length of the first electrode.

[0045] In this embodiment, the lengths of the fourth and third tabs are both less than or equal to the length of the first tab, so that the tab clusters at both ends of the first electrode assembly have different lengths, which makes it easier to distinguish the direction of the first electrode assembly connected to the first electrode terminal, and the shorter lengths of the fourth and third tabs can alleviate the problem of weak bending strength of the tab clusters.

[0046] In some embodiments, the battery cell further includes a support structure located between the first electrode assembly and the second electrode assembly, with the fourth tab and the third tab passing through the support structure to support the fourth tab and the third tab.

[0047] In this embodiment, the battery cell also includes a support frame located between the first electrode assembly and the second electrode assembly. The fourth and third tabs are inserted through the support frame to support the fourth and third tabs, thereby enabling the support frame to support the tab cluster and reduce the load on the tab cluster during operation. This alleviates the situation where the tab cluster is disconnected due to compression between the first and second electrode assemblies, making the tab cluster more stable.

[0048] In some embodiments, the support includes at least two frames, one of which is mounted on the other, and the fourth and third tabs are clamped between the mutually mounted frames.

[0049] In this embodiment, the support includes at least two frames, with one frame mounted on top of the other. The two frames can be manufactured independently and then assembled together, simplifying the installation process and minimizing interference with the fourth and third tabs.

[0050] In some embodiments, each of the frames is provided with a liquid passage hole for allowing electrolyte to flow between the first electrode assembly and the second electrode assembly, and the fourth tab and the third tab are located between the liquid passage holes of the corresponding two frames.

[0051] In this embodiment, each frame has a liquid-passing hole, which allows the electrolyte to flow between the first electrode assembly and the second electrode assembly. The liquid-passing hole increases the electrolyte's ability to flow between adjacent electrode assemblies, thereby making the battery cell more stable during operation.

[0052] In some embodiments, the electrode assembly further includes a third electrode assembly, the third electrode assembly and the first electrode assembly being arranged along the second direction, the first electrode including a planar region and an arc-shaped corner region connected to each other, the second direction being parallel to the stacking direction of the first electrode in the planar region.

[0053] In this embodiment, the third electrode assembly and the first electrode assembly are arranged along the second direction, which can reduce the size of the third electrode assembly and the first electrode assembly in the second direction. This results in a smaller empty space in the corresponding position of the corner area of ​​the third electrode assembly and the first electrode assembly within the housing, which is beneficial to increasing the proportion of the electrode assembly in the housing space and thus improving the energy density of the battery cell.

[0054] A second aspect of this application provides a battery device comprising at least two battery cells as described in any of the foregoing embodiments.

[0055] A third aspect of this application provides an electrical device, including a battery cell or a battery device as described in any of the foregoing embodiments, wherein the battery cell or the battery device is used to store or provide electrical energy.

[0056] Invention Effects

[0057] The battery cell provided in this application embodiment has a first body whose length in the first direction is greater than its length in the direction perpendicular to the first direction. This allows the first electrode sheet of this application to be manufactured without needing to cut the uncut roll of first electrode sheet along... Figure 2 The dashed line cut shown reduces the number of cut edges on the first electrode, and the burrs corresponding to the cut edge on the first electrode are also reduced accordingly. This reduces the possibility that the first separator, which is stacked with the first electrode, may be punctured by the burrs on the cut edge of the first electrode, causing insulation failure, thereby reducing the possibility of damage to the electrode assembly of the battery cell. Attached Figure Description

[0058] Figure 1 This is a front view schematic diagram of an uncut roll of conductive electrode sheet in related technologies;

[0059] Figure 2 This is a top view of an uncut roll of conductive electrode sheets in related technologies.

[0060] Figure 3This is a schematic diagram of the structure of a battery cell in some embodiments of this application, showing the first electrode assembly;

[0061] Figure 4 This is a schematic diagram of the winding of the first electrode and the first separator in some embodiments of this application;

[0062] Figure 5 This is a schematic diagram of the unfolded structure of the first electrode plate within a single battery cell in some embodiments of this application;

[0063] Figure 6 This is a schematic diagram of the assembly of the housing and the first electrode assembly in some embodiments of this application;

[0064] Figure 7 This is a schematic diagram of the assembly of the housing, the first electrode assembly, and the third electrode assembly in some embodiments of this application;

[0065] Figure 8 This is a schematic diagram of the structure of a battery cell in some embodiments of this application, where the outer casing is not shown;

[0066] Figure 9 This is a schematic diagram of the structure of the first electrode assembly in some embodiments of this application;

[0067] Figure 10 This is a schematic diagram of the structure of the second electrode assembly in some embodiments of this application;

[0068] Figure 11 This is a schematic diagram of the structure of a battery cell in some embodiments of this application, in which the first electrode assembly and the second electrode assembly are connected on opposite sides;

[0069] Figure 12 for Figure 11 A magnified view of a portion at position A in the middle;

[0070] Figure 13 This is a schematic diagram of the connection between the first electrode assembly and the second electrode assembly in one embodiment of this application. The first electrode assembly and the second electrode assembly are connected on the same side.

[0071] Figure 14 This is a schematic diagram of the structure of a battery cell in one embodiment of this application, showing the casing.

[0072] Figure 15 This is a schematic diagram of the structure of the bracket in one embodiment of this application.

[0073] Explanation of reference numerals in the attached figures

[0074] 1. Outer shell; 1a. Receiving cavity; 11. First wall; 12. Second wall; 2. Electrode assembly assembly; 21. First electrode assembly; 211. First electrode plate; 211a. Planar area; 211b. Corner area; 212. First separator; 213. First body; 214. First electrode tab; 215. Fourth electrode tab; 2151. First root; 2152. First connecting part; 22. Second electrode assembly; 223. Second body; 224. Third electrode tab; 2241. Second root; 2242. Second connecting part; 23. Third electrode assembly; 3. First electrode terminal; 4. Second electrode terminal; 5. Second electrode tab; 6. Support; 61. Frame; 61a. Liquid passage hole. Detailed Implementation

[0075] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0076] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0077] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0078] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this application; the terms “comprising” and “having” and any variations thereof in the embodiments of this application are intended to cover non-exclusive inclusion.

[0079] In the description of the embodiments of this application, technical terms such as "first," "second," and "third" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0080] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0081] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects are in an "or" relationship.

[0082] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0083] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical term "contact" should be interpreted broadly, and can be direct contact, contact through an intermediate medium layer, contact between two contacting parties with substantially no interaction force, or contact between two contacting parties with interaction force.

[0084] In related technologies, electrode assemblies include conductive electrode sheets and insulating components. An insulating component is provided between each pair of adjacent conductive electrode sheets with opposite polarities; that is, an insulating component is provided between positively polarized and negatively polarized conductive electrode sheets. The insulating component insulates the positively and negatively polarized conductive electrode sheets from each other, preventing short circuits. The conductive electrode sheets in each electrode assembly are not independent single sheets. During the production process, the entire roll of conductive electrode sheets needs to be die-cut to the required size for each electrode assembly. The cut conductive electrode sheets are then stacked with the insulating components to form different types of electrode assemblies. Specifically, a roll of positively polarized conductive electrode sheets is cut into the sizes required for each electrode assembly, and a roll of negatively polarized conductive electrode sheets is cut into the sizes required for each electrode assembly. The cut positively polarized and negatively polarized conductive electrode sheets, along with spacers, are then stacked and arranged to form different types of electrode assemblies. Please refer to [link to relevant documentation]. Figure 1 and Figure 2The uncut roll of conductive electrode sheet includes a current collector and an active material layer located on one side of the current collector in the thickness direction. The current collector protrudes from both ends of the active material layer along the axial direction of the roll of conductive electrode sheet to form tabs. That is, tabs are formed at both ends of the uncut roll of conductive electrode sheet along the axial direction, or tabs are formed at one end of the uncut roll of conductive electrode sheet along the axial direction. However, in related technologies, the length of the conductive electrode sheet in the electrode assembly in the first direction is similar to its length in the direction perpendicular to the first direction. This necessitates cutting the uncut roll of conductive electrode sheet along... Figure 2 The dotted line indicates where the conductive electrode sheet is cut to form two rolls. Each roll is then cut to the required size for each electrode assembly. Because burrs form on the cutting edges of the conductive electrode sheet during the cutting process, these burrs may puncture adjacent insulating components in the manufactured electrode assembly. This can cause insulation failure in the insulating components, resulting in a short circuit between the positively polarized and negatively polarized conductive electrode sheets, thereby damaging the electrode assembly.

[0085] In the electrode assembly of this application embodiment, the length of the first body in the first direction is greater than the length of the first body in the direction perpendicular to the first direction. Therefore, in the manufacturing process of the electrode assembly of this application embodiment, it is not necessary to cut the uncut roll of first electrode sheet along... Figure 2 As shown by the dashed line cut, the first electrode of the electrode assembly of this application has one less cut edge. Correspondingly, the burrs corresponding to the cut edge of the first electrode in the electrode assembly are reduced, which can reduce the possibility of the first separator being punctured by the burrs of the cut edge of the first electrode and causing insulation failure, thereby reducing the possibility of damage to the electrode assembly of the battery cell.

[0086] The solutions in this application embodiment can be applied to battery devices and electrical devices, but are not limited to them.

[0087] This application provides an electrical device, which includes a battery cell or a battery device for storing or providing electrical energy.

[0088] For example, an electrical device may include a battery cell for storing or providing electrical energy.

[0089] For example, an electrical device may include a battery device for storing or providing electrical energy.

[0090] The electrical device in this application embodiment also includes an electrical main body, and a battery cell or battery device is installed on the electrical main body.

[0091] Electrical devices are devices that use electrical energy as their energy source to perform corresponding functions by consuming electrical energy. Examples include, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, and ships. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc.

[0092] The electrical device refers to the main structure that consumes electrical energy to perform a corresponding function. For example, an electrical device can be a mobile phone, where the electrical device is the part that enables communication and other functions, supplied with power by individual battery cells or battery packs. Similarly, an electrical device can be a car, where the electrical device is the part that provides seating and allows the car to travel on roads, supplied with power by individual battery cells or battery packs.

[0093] The following description will be based on an embodiment of the present application, which uses a vehicle as the electrical device and a battery pack as the battery device.

[0094] One embodiment of this application provides a vehicle that can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle, etc. A battery pack is installed inside the vehicle, and the battery pack can be located at the bottom, front, or rear of the vehicle. The battery pack can be used to power the vehicle; for example, the battery pack can serve as the vehicle's operating power source. The vehicle may also include a controller and a motor, and the controller can be used to control the battery pack to power the motor. For example, the battery pack can be used to meet the vehicle's power needs during starting, navigation, and driving.

[0095] In some embodiments of this application, the battery pack can not only serve as the operating power source for the vehicle, but also as the driving power source for the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0096] The battery device in this application embodiment includes a battery cell, through which electrical energy is stored or provided.

[0097] In some embodiments, the battery device further includes a housing, in which individual battery cells are located.

[0098] The battery cells are protected by a casing.

[0099] For the battery cell in this application embodiment, please refer to [link / reference]. Figures 3-5The battery cell includes a housing 1, a first electrode terminal 3, and an electrode assembly 2. The housing 1 has a receiving cavity 1a and includes a first wall 11. The first electrode terminal 3 is fixed to the first wall 11. The electrode assembly 2 includes a first electrode assembly 21, which is received in the receiving cavity 1a. The first electrode assembly 21 includes at least two layers of first electrode sheets 211 and at least two layers of first separators 212. The first electrode sheets 211 and the first separators 212 are stacked and together form a winding structure. The first electrode sheets 211 and the first separators 212 are staggered in the stacking direction of the winding structure. The extension direction of the winding shaft of the winding structure is a first direction. The first electrode assembly 21 includes a first body 213 and a first tab 214. The length of the first body 213 in the first direction is greater than the length of the first body 213 in the direction perpendicular to the first direction. The first tab 214 protrudes from the first body 213 along the first direction toward the side close to the first wall 11 and is electrically connected to the first electrode terminal 3.

[0100] For example, Figure 3 and Figure 5 The direction shown by R1 is the first direction, which is the extension direction of the winding shaft of the winding structure. Figure 4 The direction shown by R3 is perpendicular to the first direction.

[0101] Please refer to [link / reference needed] for further explanation. Figure 3 The portion of the first electrode 211 excluding the tab and the first spacer 212 constitute the first body 213. The tab may include a first tab 214 and / or a second tab 5. When the first electrode assembly 21 only has the first tab 214, the portion of the first electrode 211 excluding the first tab 214 and the first spacer 212 constitute the first body 213. When the first electrode assembly 21 includes the first tab 214 and the second tab 5, the portion of the first electrode 211 excluding the first tab 214 and the second tab 5, together with the first spacer 212, constitute the first body 213.

[0102] Please refer to [link / reference needed] for further explanation. Figure 4 The length of the first body 213 in the direction perpendicular to the first direction refers to the maximum length in the direction perpendicular to the first direction.

[0103] For example, please refer to Figure 4 When the first electrode assembly 21 is a square winding structure, the length of the first body 213 in the vertical direction of the first direction is the maximum span of the square winding structure.

[0104] For example, Figure 3 and Figure 5 The dimensions shown in S1 are the dimensions of the first body 213 along the first direction. Figure 4The dimension shown in S2 is the dimension of the first body 213 in the direction perpendicular to the first direction, and S1 is greater than S2.

[0105] For example, when the first electrode assembly 21 is a cylindrical structure, the length of the first body 213 in the direction perpendicular to the first direction is the diameter of the cylindrical structure.

[0106] For example, the material of the housing 1 is not limited, and can be steel or aluminum.

[0107] For example, the material of the first spacer 212 can be a material with insulating properties.

[0108] For example, the material of the first tab 214 is not limited, and can be steel or aluminum.

[0109] For example, please refer to Figure 4 The first electrode 211 can be a positive electrode with positive polarity or a negative electrode with negative polarity. A first separator 212 is provided between each layer of positive electrode and the adjacent negative electrode. The positive electrode, separator and negative electrode are stacked and together form a winding structure.

[0110] For example, the dimensions of the positive electrode along the first direction are equal to the dimensions of the negative electrode along the first direction.

[0111] For example, before the first electrode 211 is wound into shape, the size of the positive electrode in the direction perpendicular to the first direction is equal to the size of the negative electrode in the direction perpendicular to the first direction.

[0112] For example, please refer to Figure 3 Along the first direction, the two electrodes located above the first body 213 are the positive electrode and the negative electrode, respectively, and the two electrodes located below the first body 213 are the positive electrode and the negative electrode, respectively.

[0113] For example, please refer to Figure 5 Before the first electrode 211 is wound into shape, the first electrode 211 has cut edges only on opposite sides in the vertical direction of the first direction, so that the first electrode 211 has only two cut edges.

[0114] In this embodiment, the length of the first body 213 in the first direction is greater than the length of the first body 213 in the direction perpendicular to the first direction. This allows the first electrode sheet 211 to be manufactured without needing to cut the uncut roll of the first electrode sheet 211 along the direction of the first body 213. Figure 2The dashed line cut shown reduces the number of cut edges on the first electrode 211, and the burrs corresponding to the cut edge on the first electrode 211 are also reduced accordingly. This reduces the possibility that the first separator 212, which is stacked with the first electrode 211, may be punctured by the burrs on the cut edge of the first electrode 211, causing insulation failure. This reduces the possibility of damage to the electrode assembly 2 of the battery cell.

[0115] In some embodiments, please refer to Figure 3 and Figure 5 The length of the first body 213 in the first direction ranges from 225mm to 1000mm, and the maximum length of the first body 213 in the vertical direction of the first direction ranges from 80mm to 130mm.

[0116] mm is a unit of length.

[0117] The dimensions of the first body 213 in the first direction and in the direction perpendicular to the first direction can be measured with vernier calipers.

[0118] For example, Figure 3 and Figure 5 The dimension shown in S1 is the dimension of the first body 213 in the first direction, 225mm≤S1≤1000mm.

[0119] For example, the dimensions of the first body 213 in the first direction may be 225 mm, 300 mm, 400 mm, 500 mm, 600 mm, 700 mm, 800 mm, 900 mm or 1000 mm.

[0120] For example, Figure 4 The dimension shown in S2 is the dimension of the first body 213 in the direction perpendicular to the first direction, 80mm≤S2≤130mm.

[0121] For example, the dimensions of the first body 213 in the vertical direction of the first direction can be 80 mm, 90 mm, 100 mm, 110 mm, 120 mm or 130 mm.

[0122] In this embodiment, the length of the first body 213 in the first direction ranges from 225mm to 1000mm, and the maximum length of the first body 213 in the vertical direction of the first direction ranges from 80mm to 130mm. On the one hand, the longer size of the first body 213 in the first direction results in fewer first electrode components 21 inside the outer casing 1 in the first direction, which helps to reduce the space occupied by the first tabs 214 between two adjacent first electrode components 21, thereby improving the energy density of the battery cell. On the other hand, the larger size of the first body 213 in the first direction than the larger size of the first body 213 in the vertical direction of the first direction eliminates the need to cut the uncut roll of first electrode sheets 211 along the first direction. Figure 2 The dashed line cut shown reduces the number of cut edges on the first electrode 211, and the burrs corresponding to the cut edge on the first electrode 211 are also reduced accordingly. This reduces the possibility that the first separator 212, which is stacked with the first electrode 211, may be punctured by the burrs on the cut edge of the first electrode 211, causing insulation failure. This reduces the possibility of damage to the electrode assembly 2 of the battery cell.

[0123] In some embodiments, please refer to Figure 3 and Figure 5 The length of the first body 213 in the first direction ranges from 500mm to 900mm, and the length of the first body 213 in the vertical direction of the first direction ranges from 90mm to 120mm.

[0124] For example, Figure 3 and Figure 5 The dimension shown in S1 is the dimension of the first body 213 in the first direction, 500mm≤S1≤900mm.

[0125] For example, the dimensions of the first body 213 in the first direction may be 500 mm, 600 mm, 700 mm, 800 mm or 900 mm.

[0126] For example, Figure 4 The dimension shown in S2 is the dimension of the first body 213 in the direction perpendicular to the first direction, 90mm≤S2≤120mm.

[0127] For example, the dimensions of the first body 213 in the vertical direction of the first direction can be 90 mm, 100 mm, 110 mm or 120 mm.

[0128] In this embodiment, the length of the first body 213 in the first direction ranges from 500mm to 900mm, and the maximum length of the first body 213 in the vertical direction of the first direction ranges from 90mm to 120mm. On the one hand, by further limiting the dimensions of the first body 213 in the first direction and in the vertical direction, the longer dimension of the first body 213 in the first direction results in fewer first electrode components 21 inside the outer casing 1 in the first direction, which helps to reduce the space occupied by the first tabs 214 between two adjacent first electrode components 21, thereby improving the energy density of the battery cell. On the other hand, the larger dimension of the first body 213 in the first direction than in the vertical direction eliminates the need to cut the uncut roll of first electrode sheets 211 along the first direction. Figure 2 The dashed line cut shown reduces the number of cut edges on the first electrode 211, and the burrs corresponding to the cut edge on the first electrode 211 are also reduced accordingly. This reduces the possibility that the first separator 212, which is stacked with the first electrode 211, may be punctured by the burrs on the cut edge of the first electrode 211, causing insulation failure. This reduces the possibility of damage to the electrode assembly 2 of the battery cell.

[0129] In some embodiments, please refer to Figure 3 and Figure 5 The ratio of the length of the first body 213 in the first direction to the maximum length of the first body 213 in the direction perpendicular to the first direction is in the range of 1.5 to 13.

[0130] For example, the ratio of the length of the first body 213 in the first direction to the maximum length of the first body 213 in the direction perpendicular to the first direction can be 1.5, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 or 13.

[0131] In this embodiment, the ratio of the length of the first body 213 in the first direction to the maximum length of the first body 213 in the perpendicular direction of the first direction ranges from 1.5 to 13, such that the dimension of the first body 213 in the first direction is larger than the dimension of the first body 213 in the perpendicular direction of the first direction, which eliminates the need to cut the uncut roll of first electrode sheet 211 along the... Figure 2 The dashed line cut shown reduces the number of cut edges on the first electrode 211, and the burrs corresponding to the cut edge on the first electrode 211 are also reduced accordingly. This reduces the possibility that the first separator 212, which is stacked with the first electrode 211, may be punctured by the burrs on the cut edge of the first electrode 211, causing insulation failure. This reduces the possibility of damage to the electrode assembly 2 of the battery cell.

[0132] In some embodiments, please refer to Figure 3 and Figure 5The ratio of the length of the first body 213 in the first direction to the maximum length of the first body 213 in the direction perpendicular to the first direction is in the range of 4 to 10.

[0133] For example, the ratio of the length of the first body 213 in the first direction to the maximum length of the first body 213 in the direction perpendicular to the first direction can be 4, 5, 6, 7, 8, 9 or 10.

[0134] In this embodiment, the ratio of the length of the first body 213 in the first direction to the maximum length of the first body 213 in the perpendicular direction of the first direction ranges from 4 to 10, such that the dimension of the first body 213 in the first direction is larger than the dimension of the first body 213 in the perpendicular direction of the first direction, which eliminates the need to cut the uncut roll of first electrode sheet 211 along the... Figure 2 The dashed line cut shown reduces the number of cut edges on the first electrode 211, and the burrs corresponding to the cut edge on the first electrode 211 are also reduced accordingly. This reduces the possibility that the first separator 212, which is stacked with the first electrode 211, may be punctured by the burrs on the cut edge of the first electrode 211, causing insulation failure. This reduces the possibility of damage to the electrode assembly 2 of the battery cell.

[0135] In some embodiments, please refer to Figure 3 The outer casing 1 includes a second wall 12, and the battery cell also includes a second electrode terminal 4 mounted on the second wall 12. The first wall 11 is located at one end of the outer casing 1 along a first direction, and the second wall 12 is located at the other end of the outer casing 1 along the first direction. The electrode assembly 2 also includes a second tab 5. The second tab 5 is located at one end of the electrode assembly 2 along the first direction away from the first tab 214 and is electrically connected to the second electrode terminal 4. The first tab 214 with positive polarity and the first tab 214 with negative polarity are respectively electrically connected to the corresponding first electrode terminal 3, and the second tab 5 with positive polarity and the second tab 5 with negative polarity are respectively electrically connected to the corresponding second electrode terminal 4.

[0136] For example, the materials of the first electrode terminal 3 and the second electrode terminal 4 are not limited, and can be, for example, copper or aluminum.

[0137] For example, please refer to Figure 3 When the electrode assembly 2 includes only one first electrode assembly 21, the second electrode tab 5 is formed on the first body 213 and protrudes from the first body 213 along the first direction toward the side close to the second wall 12.

[0138] Exemplarily, the electrode assembly 2 further includes a second electrode assembly 22 arranged along a first direction with the first electrode assembly 21. The second electrode assembly 22 is electrically connected to the first electrode assembly 21 and is located at one end of the first electrode assembly 21 facing the second wall 12 along the first direction. The second electrode assembly 22 includes at least two layers of second electrode sheets and at least two layers of second spacers. The second electrode sheets and second spacers are stacked and together form a wound structure. The second electrode sheets and second spacers are staggered in the stacking direction of the wound structure. The second electrode assembly 22 includes a second body 223. The portion of the second electrode sheet other than the tab and the second spacers constitute the second body 223.

[0139] For example, when the electrode assembly 2 further includes a second electrode assembly 22 arranged along a first direction with the first electrode assembly 21, a second tab 5 is formed on the second body 223, and the second tab 5 protrudes from the second body 223 along the first direction toward the side close to the second wall 12.

[0140] For example, the second electrode assembly 22 may be provided without the second electrode tab 5.

[0141] In this embodiment, the first wall 11 and the second wall 12 are located at opposite ends of the outer casing 1 along the first direction. The first wall 11 is fitted with a first electrode terminal 3, and the second wall 12 is fitted with a second electrode terminal 4. A positively polarized first electrode tab 214 and a negatively polarized first electrode tab 214 are electrically connected to their respective first electrode terminals 3. Similarly, a positively polarized second electrode tab 5 and a negatively polarized second electrode tab 5 are electrically connected to their respective second electrode terminals 4. This design allows each end of the battery cell to form its own current loop along the first direction, preventing the current from flowing from one end to the other along the first direction. This promotes more uniform heating of the battery cell in the first direction. The shorter distance the current travels within the battery cell also reduces the heat generated during normal operation, thus improving the safety of the battery cell.

[0142] It is understood that the number of first electrode terminals 3 installed on the first wall 11 can be one, and the number of second electrode terminals 4 installed on the second wall 12 can be one, so that the current in the battery cell flows from one end of the battery cell to the other end along the first direction.

[0143] In some embodiments, please refer to Figure 3 and Figure 5The outer casing 1 includes a second wall 12, and the battery cell also includes a second electrode terminal 4 mounted on the second wall 12. The first wall 11 is located at one end of the outer casing 1 along the first direction, and the second wall 12 is located at the other end of the outer casing 1 along the first direction. The electrode assembly 2 also includes a second tab 5, which is located at one end of the electrode assembly 2 along the first direction away from the first tab 214 and is electrically connected to the second electrode terminal 4. The dimension of the outer casing 1 along the first direction is the first dimension. The maximum dimension of the first electrode terminal 3 protruding from the first wall 11 along the first direction is the second dimension. The maximum dimension of the second electrode terminal 4 protruding from the second wall 12 along the first direction is the third dimension. The ratio of the sum of the second dimension and the third dimension to the first dimension is the first ratio. The first ratio is greater than 0 and less than or equal to 0.02.

[0144] For example, Figure 3 The dimension shown in S3 is the first dimension. Figure 3 The dimension shown in S4 is the second dimension. Figure 3 The dimension shown in S5 is the third dimension.

[0145] For example, the first ratio can be expressed as (S4+S5) / S3.

[0146] For example, 0 < (S4 + S5) / S3 ≤ 0.02.

[0147] For example, 400 mm ≤ S3 ≤ 1400 mm.

[0148] For example, the second dimension is equal to the third dimension.

[0149] For example, the first ratio can be 0.01 or 0.02.

[0150] It should be noted that, with the sum of the second and third dimensions remaining unchanged, if the first ratio is too small, the size of the portion of the first electrode terminal 3 and the second electrode terminal 4 located inside the housing 1 will be larger, occupying more space inside the housing 1 and reducing the energy density of the battery cell. If the first ratio is too large, the size of the portion of the first electrode terminal 3 and the second electrode terminal 4 located inside the housing 1 will be smaller. Although this can increase the proportion of the electrode assembly 2 inside the housing 1, the empty space inside the housing 1 will be smaller, reducing the safety of the battery cell.

[0151] In this embodiment, the first ratio is greater than 0, so that the first electrode terminal 3 and the second electrode terminal 4 protrude from the outer casing 1 along the first direction, which facilitates the connection of the battery cell with adjacent battery cells or electrical devices. The first ratio is less than or equal to 0.02. When the dimensions of the first electrode terminal 3 and the second electrode terminal 4 in the first direction remain unchanged, it is beneficial to balance the relationship between the energy density and safety of the battery cell, so that the battery cell can have a certain degree of safety while having a high energy density.

[0152] Understandably, the first ratio can also be greater than 0.02.

[0153] In some embodiments, please refer to Figure 3 and Figure 5 The first ratio is greater than or equal to 0.008, and the first ratio is less than or equal to 0.015.

[0154] For example, the first ratio may be 0.008, 0.01, or 0.015.

[0155] In this embodiment, the first ratio is greater than or equal to 0.008, which causes the first electrode terminal 3 and the second electrode terminal 4 to protrude from the outer casing 1 along the first direction, facilitating the connection of the battery cell with adjacent battery cells or electrical devices. When the first ratio is less than or equal to 0.015, the dimensions of the first electrode terminal 3 and the second electrode terminal 4 remain unchanged in the first direction, which helps to balance the relationship between the energy density and safety of the battery cell, so that the battery cell can have a certain degree of safety while having a high energy density.

[0156] In some embodiments, please refer to Figure 3 The outer casing 1 includes a second wall 12, and the battery cell also includes a second electrode terminal 4 mounted on the second wall 12. The first wall 11 is located at one end of the outer casing 1 along the first direction, and the second wall 12 is located at the other end of the outer casing 1 along the first direction. The electrode assembly 2 also includes a second tab 5, which is located at one end of the electrode assembly 2 along the first direction away from the first tab 214 and is electrically connected to the second electrode terminal 4. The electrode assembly 2 includes only one first electrode assembly 21. The dimension of the outer casing 1 along the first direction is a first dimension, and the dimension of the first body 213 along the first direction is a fourth dimension. The ratio of the fourth dimension to the first dimension is a second ratio, which is greater than or equal to 0.96 and less than or equal to 0.99.

[0157] For example, Figure 3 The dimension shown in S1 is the fourth dimension, and the dimension shown in S3 is the first dimension. S3 is larger than S1.

[0158] For example, the second ratio can be expressed as S1 / S3.

[0159] For example, the second ratio can be 0.96, 0.97, 0.98 or 0.99.

[0160] For example, the outer casing 1 along Figure 3 The dimensions in the left-right direction can range from 60 mm to 140 mm, and the outer shell 1 along... Figure 6 or Figure 7 The vertical dimension can range from 15 mm to 35 mm.

[0161] It should be noted that if the size of the outer casing 1 along the first direction remains unchanged, a smaller second ratio results in a smaller proportion of the electrode assembly 2 within the outer casing 1, reducing the energy density of the battery cell. If the second ratio is too large, although it can increase the proportion of the electrode assembly 2 within the outer casing 1, the empty space within the outer casing 1 is smaller, which is not conducive to accommodating the gas within the outer casing 1 and reduces the safety of the battery cell.

[0162] In this embodiment, the second ratio is greater than or equal to 0.96, which allows the electrode assembly 2 to make full use of the space inside the housing 1, thereby increasing the space ratio of the electrode assembly 2 inside the housing 1 and thus improving the energy density of the battery cell; the second ratio is less than or equal to 0.99, which allows the housing 1 to have a certain amount of spare space to accommodate the gas inside the housing 1, thereby improving the safety of the battery cell.

[0163] Understandably, the second ratio could also be less than 0.96.

[0164] In some embodiments, the second ratio is greater than or equal to 0.97, and the second ratio is less than or equal to 0.99.

[0165] For example, the second ratio can be 0.97, 0.98, or 0.99.

[0166] In this embodiment, the second ratio is greater than or equal to 0.97, which allows the electrode assembly 2 to make full use of the space inside the housing 1, thereby increasing the space ratio of the electrode assembly 2 inside the housing 1 and thus improving the energy density of the battery cell; the second ratio is less than or equal to 0.99, which allows the housing 1 to have a certain amount of spare space to accommodate the gas inside the housing 1, thereby improving the safety of the battery cell.

[0167] In some embodiments, the first wall 11 is located at one end of the housing 1 along the first direction, the size of the housing 1 along the first direction is the first dimension, the maximum size of the first electrode terminal 3 protruding from the first wall 11 along the first direction is the second dimension, the ratio of the second dimension to the first dimension is the third ratio, the third ratio is greater than or equal to 0, and the third ratio is less than or equal to 0.01.

[0168] It should be explained that the outer casing 1 includes a second wall 12, which is located at the other end of the outer casing 1 along the first direction. The first wall 11 and the second wall 12 are arranged opposite to each other along the first direction, and there is no second electrode terminal 4 on the second wall 12.

[0169] For example, Figure 3 The dimension shown in S3 is the first dimension. Figure 3 The dimension shown in S4 is the second dimension.

[0170] For example, the third ratio can be expressed as S4 / S3.

[0171] For example, 0 < S4 / S3 ≤ 0.02.

[0172] For example, 400 mm ≤ S3 ≤ 1400 mm.

[0173] For example, the third ratio can be 0.005 or 0.01.

[0174] In this embodiment, the third ratio is greater than 0, so that the first electrode terminal 3 protrudes from the outer casing 1 along the first direction, which facilitates the connection of the battery cell with adjacent battery cells or electrical devices. When the third ratio is less than or equal to 0.01, the first electrode terminal 3 remains unchanged in the first direction, which helps to balance the relationship between the energy density and safety of the battery cell, so that the battery cell can have a certain degree of safety while having a high energy density.

[0175] Understandably, the third ratio can also be greater than 0.01.

[0176] In some embodiments, the first wall 11 is located at one end of the housing 1 along the first direction, the electrode assembly 2 includes only one first electrode assembly 21, the size of the housing 1 along the first direction is the first dimension, the size of the first body 213 along the first direction is the fourth dimension, the ratio of the fourth dimension to the first dimension is the second ratio, the second ratio is greater than or equal to 0.98, and the second ratio is less than or equal to 0.99.

[0177] It should be explained that the outer casing 1 includes a second wall 12, which is located at the other end of the outer casing 1 along the first direction. The first wall 11 and the second wall 12 are arranged opposite to each other along the first direction, and there is no second electrode terminal 4 on the second wall 12.

[0178] For example, the second ratio can be 0.98, 0.985, or 0.99.

[0179] In this embodiment, the second ratio is greater than or equal to 0.98, which allows the electrode assembly 2 to make full use of the space inside the housing 1, thereby increasing the space ratio of the electrode assembly 2 inside the housing 1 and thus improving the energy density of the battery cell; the second ratio is less than or equal to 0.99, which allows the housing 1 to have a certain amount of spare space to accommodate the gas inside the housing 1, thereby improving the safety of the battery cell.

[0180] Understandably, the second ratio can also be less than 0.98.

[0181] In some embodiments, please refer to Figures 8 to 12 The electrode assembly 2 further includes a second electrode assembly 22, which includes at least two layers of second electrode sheets and at least two layers of second spacers. The second electrode sheets and second spacers are stacked and together form a winding structure. The second electrode sheets and second spacers are staggered in the stacking direction of the winding structure. The second electrode assembly 22 includes a second body 223 and a third electrode tab 224. The third electrode tab 224 protrudes from the second body 223 along a first direction toward the side close to the first wall 11. The outer shell 1 includes a second electrode assembly 224 arranged opposite to the first wall 11 along the first direction. The second wall 12 and the first electrode assembly 21 further include a fourth electrode tab 215. The fourth electrode tab 215 protrudes from the first body 213 along the first direction toward the side close to the second wall 12. The first electrode plate 211 has a first sub-electrode tab, and the fourth electrode tab 215 is an electrode tab cluster formed by multiple first sub-electrode tabs. The second electrode plate has a second sub-electrode tab, and the third electrode tab 224 is an electrode tab cluster formed by multiple second sub-electrode tabs. The first electrode assembly 21 and the second electrode assembly 22 are arranged along the first direction. The third electrode tab 224 and the fourth electrode tab 215 are arranged opposite each other and electrically connected.

[0182] It should be explained that the portion of the second electrode plate other than the tab and the second insulating member constitute the second body 223. When the tab of the second electrode assembly 22 only includes the third tab 224, the portion of the second electrode plate other than the third tab 224 and the second insulating member constitute the second body 223. When the tab of the second electrode assembly 22 includes both the second tab 5 and the third tab 224, the portion of the second electrode plate other than the second tab 5 and the third tab 224 and the second insulating member constitute the second body 223.

[0183] It should be noted that the electrical connection between the third tab 224 and the fourth tab 215 refers to a direct connection between the third tab 224 and the fourth tab 215, and not an indirect connection through an adapter or other connection structure.

[0184] In this embodiment, the third tab 224 and the fourth tab 215 are arranged opposite to each other and electrically connected, allowing for direct connection between them without the need for an adapter. This eliminates some mechanical structural components in the battery cell, resulting in lower battery cell cost. Furthermore, the tab clusters between adjacent first electrode assemblies 21 and second electrode assemblies 22 are directly connected, and the strength of the tab clusters is essentially the same. This ensures a good connection between the first electrode assembly 21 and the second electrode group, thereby alleviating the connection integrity issues between the first electrode assembly 21 and the second electrode group.

[0185] In some embodiments, please refer to Figure 4 , Figures 9-12 The fourth electrode tab 215 includes a first root portion 2151 close to the first body 213 and a first connecting portion 2152 away from the first body 213. The first connecting portion 2152 is in a constricted state and is located on one side of the winding shaft along the second direction. The third electrode tab 224 includes a second root portion 2241 close to the second body 223 and a second connecting portion 2242 away from the second body 223. The second connecting portion 2242 is in a constricted state and is located on the other side of the winding shaft along the second direction. The first electrode 211 includes a planar region 211a and an arc-shaped corner region 211b connected to each other. The second direction is parallel to the stacking direction of the first electrode 211 in the planar region 211a.

[0186] For example, the winding shaft of the first electrode assembly 21 is arranged coaxially with the winding shaft of the second electrode assembly 22.

[0187] For example, please refer to Figure 9 and Figure 10 The first and second directions are arranged perpendicularly.

[0188] For example, please refer to Figure 11 and 12 At least the first connecting part 2152 is connected to the third electrode 224.

[0189] For example, please refer to Figure 11 and 12 At least the first connecting part 2152 is welded to the third electrode tab 224.

[0190] For example, please refer to Figure 11 and 12 At least the second connecting part 2242 is connected to the fourth pole piece 215.

[0191] For example, please refer to Figure 11 and 12 At least the second connecting part 2242 is welded to the fourth electrode tab 215.

[0192] For example, please refer to Figures 9-12 The thickness direction of the third tab 224 and the fourth tab 215 are both arranged along the second direction.

[0193] For example, please refer to Figure 11 and 12 The third tab 224 and the fourth tab 215 are arranged along the thickness direction of the fourth tab 215.

[0194] For example, the thickness direction of the fourth electrode 215 is aligned with the thickness direction of the first electrode assembly 21.

[0195] For example, Figures 9-12 The direction shown by R1 is the first direction, and the direction shown by R2 is the second direction.

[0196] In this embodiment, the fourth tab 215 includes a first connecting portion 2152 in a converging state, and the third tab 224 includes a second connecting portion 2242 in a converging state. The converging of the tab cluster to form the connecting portion increases the local strength of the tab cluster and alleviates deformation. Furthermore, the first connecting portion 2152 is located on one side of the first body 213 along the first direction, and the second connecting portion 2242 is located on the other side of the second body 223 along the first direction. This allows for a larger contact area between adjacent first electrode assemblies 21 and second electrode assemblies 22, resulting in higher connection strength. Moreover, the first electrode assemblies 21 and 22 do not require offset or only require a small offset during welding, reducing the positioning difficulty between adjacent first electrode assemblies 21 and 22 during welding and lowering the processing difficulty of the battery cell.

[0197] In some embodiments, please refer to Figures 9-12 Along the second direction, all the first sub-pole tabs in the fourth tab 215 are located on one side of the winding shaft, and all the second sub-pole tabs in the third tab 224 are located on the other side of the winding shaft.

[0198] For example, both the first connecting portion 2152 and the first root portion 2151 are connected to the third electrode tab 224.

[0199] For example, both the first connecting portion 2152 and the first root portion 2151 are welded to the third electrode tab 224.

[0200] In the embodiment of this application, all the first sub-tabs in the fourth tab 215 are located on one side of the winding shaft, and all the second sub-tabs in the third tab 224 are located on the other side of the winding shaft. The fourth tab 215 can extend a longer distance toward the second electrode assembly 22 along the first direction, thereby shortening the length occupied by the fourth tab 215 and the third tab 224 after welding, so that the first body 213 and the second body 223 can be arranged with a longer length along the first direction, thereby increasing the energy density of the battery cell.

[0201] In some embodiments, along the second direction, the first root portion 2151 and / or the second root portion 2241 span across opposite sides of the corresponding winding shaft.

[0202] In this embodiment, the first root portion 2151 and / or the second root portion 2241 are disposed across the opposite sides of the corresponding winding shaft. The larger size of the electrode root portion along the second direction can alleviate the situation where the opposite electrode clusters are inserted into the electrode body, thereby causing a short circuit.

[0203] In some embodiments, please refer to Figure 4 and Figure 13 The fourth electrode tab 215 includes a first root portion 2151 close to the first body 213 and a first connecting portion 2152 away from the first body 213. The first connecting portion 2152 is in a constricted state and is located on one side of the winding shaft along the second direction. The third electrode tab 224 includes a second root portion 2241 close to the second body 223 and a second connecting portion 2242 away from the second body 223. The second connecting portion 2242 is in a constricted state and is located on the same side of the winding shaft along the second direction. The first electrode 211 includes a planar region 211a and an arc-shaped corner region 211b connected to each other. The second direction is parallel to the stacking direction of the first electrode 211 in the planar region 211a.

[0204] In this embodiment of the application, along the second direction, the first connecting part 2152 and the second connecting part 2242 are located on the same side of the winding shaft. Both the first connecting part 2152 and the second connecting part 2242 can alleviate the situation where the opposite tabs are inserted into the electrode body, thereby causing a short circuit.

[0205] In some embodiments, the lengths of the third tab 224 and the fourth tab 215 are both less than or equal to the length of the first tab 214.

[0206] In this embodiment, the lengths of the fourth tab 215 and the third tab 224 are both less than or equal to the length of the first tab 214. This makes it easier to distinguish the direction of the first electrode assembly 21 connected to the first electrode terminal 3 by the inconsistent lengths of the tab clusters at both ends of the first electrode assembly 21. Furthermore, the shorter lengths of the fourth tab 215 and the third tab 224 can alleviate the problem of weak bending strength of the tab clusters.

[0207] It is understood that the embodiments of this application are not limited to the lengths of the third electrode 224 and the fourth electrode 215 being less than or equal to the length of the first electrode 214. Exemplarily, the lengths of the third electrode 224 and the fourth electrode 215 are both greater than the length of the first electrode 214.

[0208] In some embodiments, please refer to Figure 14 The battery cell also includes a support 6, which is located between the first electrode assembly 21 and the second electrode assembly 22. The fourth tab 215 and the third tab 224 are inserted through the support 6 so that the support 6 supports the fourth tab 215 and the third tab 224.

[0209] For example, the support 6 is made of an insulating material.

[0210] For example, the support 6 is made of a material that is difficult to react with the electrolyte.

[0211] In this embodiment, the battery cell further includes a support 6, which is located between the first electrode assembly 21 and the second electrode assembly 22. The fourth tab 215 and the third tab 224 are inserted through the support 6 so that the support 6 supports the fourth tab 215 and the third tab 224, thereby enabling the support 6 to support the tab cluster to reduce the load on the tab cluster during operation, thereby alleviating the situation where the tab cluster is disconnected due to the compression between the first electrode assembly 21 and the second electrode assembly 22, and the tab cluster is more stable.

[0212] It is understood that the embodiments of this application do not limit whether a support 6 is provided between adjacent first electrode assembly 21 and second electrode assembly 22.

[0213] In some embodiments, please refer to Figure 15 The bracket 6 includes at least two frames 61, one of which is mounted on the other, and the fourth tab 215 and the third tab 224 are clamped between the mutually mounted frames 61.

[0214] In this embodiment, the bracket 6 includes at least two frames 61, with one frame 61 mounted on the other frame 61. The two frames 61 of the bracket 6 can be manufactured independently and then assembled together, simplifying the installation process and minimizing interference with the fourth tab 215 and the third tab 224.

[0215] It is understood that the embodiments of this application are not limited to the bracket 6 comprising two frames 61, one frame 61 being mounted on the other frame 61. Exemplarily, the bracket 6 is a one-piece molded structure.

[0216] In some embodiments, please refer to Figure 15 Each frame 61 has a liquid passage hole 61a formed thereon, which is used to allow the electrolyte to flow between the first electrode assembly 21 and the second electrode assembly 22. The fourth tab 215 and the third tab 224 are located between the liquid passage holes 61a of the corresponding two frames 61.

[0217] For example, the number of liquid passage holes 61a is at least two, and the at least two liquid passage holes 61a are arranged at intervals.

[0218] In this embodiment, each frame 61 has a liquid passage hole 61a, which allows the electrolyte to flow between the first electrode assembly 21 and the second electrode assembly 22. The liquid passage hole 61a increases the ability of the electrolyte to flow between adjacent electrode assemblies, thereby making the battery cell more stable during operation.

[0219] It is understood that the embodiments of this application do not limit whether or not a liquid-filled hole 61a is formed on the frame 61.

[0220] In some embodiments, please refer to Figure 7 The electrode assembly 2 also includes a third electrode assembly 23. The third electrode assembly 23 and the first electrode assembly 21 are arranged along a second direction. The first electrode 211 includes a planar region 211a and an arc-shaped corner region 211b that are connected to each other. The second direction is parallel to the stacking direction of the first electrode 211 in the planar region 211a.

[0221] It should be noted that the structure of the third electrode assembly 23 is the same as that of the first electrode assembly 21.

[0222] For example, please refer to Figure 7 The number of first electrode assembly 21 and the number of third electrode assembly 23 are both two, and the first electrode assembly 21 and the third electrode assembly 23 are arranged alternately along the second direction.

[0223] For example, at least one first electrode assembly 21 and at least one third electrode assembly 23 are arranged along a second direction, with adjacent electrode assemblies connected in parallel to reduce the voltage of the battery cell.

[0224] For example, please refer to Figure 4 The outer contour of the planar area 211a can be square, and the outer contour of the corner area 211b can be arc-shaped.

[0225] For example, please refer to Figure 6 and Figure 7 , Figure 6 There is only one first electrode assembly 21 inside the outer casing 1. The first electrode assembly 21 has a larger size in the second direction, so that the space inside the outer casing 1 has a large amount of empty space at the corresponding position of the corner area 211b of the first electrode assembly 21. Figure 7 There are a total of four first electrode components 21 and three electrode components 23. The first electrode components 21 and three electrode components 23 are smaller in size in the second direction, so that the space inside the housing 1 is smaller at the corresponding positions of the corner area 211b of the first electrode components 21 and the third electrode components 23.

[0226] In this embodiment, the third electrode assembly 23 and the first electrode assembly 21 are arranged along the second direction, which can reduce the size of the third electrode assembly 23 and the first electrode assembly 21 in the second direction. This results in a smaller empty space in the corresponding position of the corner area 211b of the third electrode assembly 23 and the first electrode assembly 21 within the housing 1, which is beneficial to increasing the proportion of the electrode assembly in the space within the housing 1, and thus beneficial to increasing the energy density of the battery cell.

[0227] For the battery cells in the embodiments of this application, please refer to [link / reference needed]. Figures 3 to 15 The battery cell includes a casing 1 and an electrode assembly, which includes conductive electrode sheets and a separator. In this application, the conductive electrode sheet has tabs connected to both ends of its electrode body along the axial direction of the separator's winding shaft. That is, the conductive electrode sheet adopts a structure with tabs at both ends, matching the structure of the uncut roll of conductive electrode sheets. Therefore, during the manufacturing process of the electrode assembly in this application, it is not necessary to further process the uncut roll of conductive electrode sheets along... Figure 2 The dashed line cut shown reduces the number of cut edges on the conductive electrode sheet of the electrode assembly, thereby reducing the burrs on the conductive electrode sheet and the cut edge. This reduces the possibility of insulation failure caused by the burrs on the cut edge of the conductive electrode sheet puncturing the insulating component, thus reducing the possibility of damage to the electrode assembly of the battery cell.

[0228] The size of the electrode body along the winding axis ranges from 225 mm to 1000 mm, and further, it can be from 500 mm to 900 mm. When the size of the electrode body along the winding axis corresponds to the width of the electric vehicle, a larger size of the electrode body along the winding axis is beneficial to improving the energy density of the battery device.

[0229] The outer casing 1 of the battery cell is equipped with a first electrode terminal 3 and a second electrode terminal 4 at both ends along the winding shaft, so that the battery cell heats up more evenly along the axial direction of the winding shaft.

[0230] The ratio of the sum of the second and third dimensions of the first electrode terminal 3 protruding from the outer casing 1 along the winding axis to the first dimension of the outer casing 1 along the axial direction of the winding axis is in the range of 0 to 0.02. Further, the range of the first ratio can be 0.008 to 0.015, which is beneficial to balancing the contradiction between the energy density and safety of the battery cell.

[0231] The ratio of the fourth dimension to the first dimension of the electrode body along the winding axis ranges from 0.96 to 0.99. Further, the second ratio can range from 0.97 to 0.99, which is beneficial to balancing the contradiction between the energy density and safety of the battery cell.

[0232] The number of electrode components can be one, which is beneficial to improving the energy density of the battery cell; the number of electrode components can also be multiple, and multiple electrode components can be arranged along the axial direction of the winding shaft, which is convenient for winding and forming the electrode components; multiple electrode components can also be arranged along a second direction, which is beneficial to improving the energy density of the battery cell.

[0233] The above description is merely a preferred embodiment of this application and is not intended to limit the application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A battery cell, characterized in that, include: A housing having a receiving cavity, the housing including a first wall; The first electrode terminal is fixed to the first wall; An electrode assembly includes a first electrode assembly housed in the receiving cavity. The first electrode assembly includes at least two layers of first electrode sheets and at least two layers of first spacers. The first electrode sheets and the first spacers are stacked and together form a winding structure. The first electrode sheets and the first spacers are staggered in the stacking direction of the winding structure. The winding axis of the winding structure extends in a first direction. The first electrode assembly includes a first body and a first tab. The length of the first body in the first direction is greater than the length of the first body in the direction perpendicular to the first direction. The first tab protrudes from the first body along the first direction toward a side close to the first wall and is electrically connected to the first electrode terminal.

2. The battery cell according to claim 1, characterized in that, The length of the first body in the first direction ranges from 225mm to 1000mm, and the maximum length of the first body in the vertical direction of the first direction ranges from 80mm to 130mm.

3. The battery cell according to claim 2, characterized in that, The length of the first body in the first direction ranges from 500mm to 900mm, and the length of the first body in the perpendicular direction of the first direction ranges from 90mm to 120mm.

4. The battery cell according to claim 1, characterized in that, The ratio of the length of the first body in the first direction to the maximum length of the first body in the direction perpendicular to the first direction ranges from 1.5 to 13.

5. The battery cell according to claim 4, characterized in that, The ratio of the length of the first body in the first direction to the maximum length of the first body in the direction perpendicular to the first direction is in the range of 4 to 10.

6. The battery cell according to any one of claims 1 to 5, characterized in that, The housing includes a second wall, and the battery cell further includes a second electrode terminal mounted on the second wall. The first wall is located at one end of the housing along the first direction, and the second wall is located at the other end of the housing along the first direction. The electrode assembly further includes a second tab, which is located at one end of the electrode assembly along the first direction away from the first tab and electrically connected to the second electrode terminal. The first tab with positive polarity and the first tab with negative polarity are respectively electrically connected to the corresponding first electrode terminal, and the second tab with positive polarity and the second tab with negative polarity are respectively electrically connected to the corresponding second electrode terminal.

7. The battery cell according to any one of claims 1 to 5, characterized in that, The housing includes a second wall, and the battery cell further includes a second electrode terminal mounted on the second wall. The first wall is located at one end of the housing along the first direction, and the second wall is located at the other end of the housing along the first direction. The electrode assembly further includes a second tab, which is located at the end of the electrode assembly along the first direction away from the first tab and electrically connected to the second electrode terminal. The dimension of the housing along the first direction is a first dimension. The maximum dimension of the first electrode terminal protruding from the first wall along the first direction is a second dimension. The maximum dimension of the second electrode terminal protruding from the second wall along the first direction is a third dimension. The ratio of the sum of the second dimension and the third dimension to the first dimension is a first ratio. The first ratio is greater than 0 and less than or equal to 0.

02.

8. The battery cell according to claim 7, characterized in that, The first ratio is greater than or equal to 0.008, and the first ratio is less than or equal to 0.

015.

9. The battery cell according to any one of claims 1 to 5, characterized in that, The housing includes a second wall, and the battery cell further includes a second electrode terminal mounted on the second wall. The first wall is located at one end of the housing along the first direction, and the second wall is located at the other end of the housing along the first direction. The electrode assembly further includes a second tab, which is located at the end of the electrode assembly along the first direction away from the first tab and electrically connected to the second electrode terminal. The electrode assembly includes only one first electrode assembly. The dimension of the housing along the first direction is a first dimension, and the dimension of the first body along the first direction is a fourth dimension. The ratio of the fourth dimension to the first dimension is a second ratio, which is greater than or equal to 0.96 and less than or equal to 0.

99.

10. The battery cell according to claim 9, characterized in that, The second ratio is greater than or equal to 0.97, and the second ratio is less than or equal to 0.

99.

11. The battery cell according to any one of claims 1 to 5, characterized in that, The first wall is located at one end of the outer shell along the first direction. The size of the outer shell along the first direction is the first dimension. The maximum size of the first electrode terminal protruding from the first wall along the first direction is the second dimension. The ratio of the second dimension to the first dimension is the third ratio. The third ratio is greater than or equal to 0 and less than or equal to 0.

01.

12. The battery cell according to any one of claims 1 to 5, characterized in that, The first wall is located at one end of the housing along the first direction, the electrode assembly includes only one first electrode assembly, the size of the housing along the first direction is a first dimension, the size of the first body along the first direction is a fourth dimension, the ratio of the fourth dimension to the first dimension is a second ratio, the second ratio is greater than or equal to 0.98, and the second ratio is less than or equal to 0.

99.

13. The battery cell according to any one of claims 1 to 5, characterized in that, The electrode assembly further includes a second electrode assembly, which includes at least two layers of second electrode sheets and at least two layers of second spacers. The second electrode sheets and the second spacers are stacked and together form a wound structure. The second electrode sheets and the second spacers are staggered in the stacking direction of the wound structure. The second electrode assembly includes a second body and a third electrode tab. The third electrode tab protrudes from the second body along the first direction toward a side close to the first wall. The outer shell includes a second wall arranged opposite to the first wall along the first direction. The first electrode assembly further includes a fourth electrode tab. The fourth electrode tab protrudes from the first body along the first direction toward a side close to the second wall. The first electrode sheet has a first sub-electrode tab. The fourth electrode tab is an electrode tab cluster formed by multiple first sub-electrode tabs. The second electrode sheet has a second sub-electrode tab. The third electrode tab is an electrode tab cluster formed by multiple second sub-electrode tabs. The first electrode assembly and the second electrode assembly are arranged along the first direction, and the third electrode tab and the fourth electrode tab are arranged opposite to each other and electrically connected.

14. The battery cell according to claim 13, characterized in that, The fourth electrode tab includes a first root portion close to the first body and a first connecting portion away from the first body. The first connecting portion is in a constricted state and is located on one side of the winding shaft along the second direction. The third electrode tab includes a second root portion close to the second body and a second connecting portion away from the second body. The second connecting portion is in a constricted state and is located on the other side of the winding shaft along the second direction. The first electrode includes a planar region and an arc-shaped corner region connected to each other. The second direction is parallel to the stacking direction of the first electrode in the planar region.

15. The battery cell according to claim 14, characterized in that, Along the second direction, all the first sub-taps in the fourth electrode tab are located on one side of the winding shaft, and all the second sub-taps in the third electrode tab are located on the other side of the winding shaft.

16. The battery cell according to claim 14, characterized in that, Along the second direction, the first root portion and / or the second root portion spans across the opposite sides of the corresponding winding shaft.

17. The battery cell according to claim 13, characterized in that, The fourth electrode tab includes a first root portion close to the first body and a first connecting portion away from the first body. The first connecting portion is in a constricted state and is located on one side of the winding shaft along the second direction. The third electrode tab includes a second root portion close to the second body and a second connecting portion away from the second body. The second connecting portion is in a constricted state and is located on the same side of the winding shaft along the second direction. The first electrode includes a planar region and an arc-shaped corner region connected to each other. The second direction is parallel to the stacking direction of the first electrode in the planar region.

18. The battery cell according to claim 13, characterized in that, The lengths of the third and fourth electrodes are both less than or equal to the length of the first electrode.

19. The battery cell according to claim 13, characterized in that, The battery cell also includes a support frame located between the first electrode assembly and the second electrode assembly. The fourth tab and the third tab are inserted through the support frame so that the support frame supports the fourth tab and the third tab.

20. The battery cell according to claim 19, characterized in that, The support includes at least two frames, one of which is mounted on the other, and the fourth and third pole pieces are clamped between the mutually mounted frames.

21. The battery cell according to claim 20, characterized in that, Each of the frames has a liquid passage hole for allowing electrolyte to flow between the first electrode assembly and the second electrode assembly, and the fourth tab and the third tab are located between the liquid passage holes of the corresponding two frames.

22. The battery cell according to any one of claims 1 to 5, characterized in that, The electrode assembly further includes a third electrode assembly, which and the first electrode assembly are arranged along the second direction. The first electrode includes a planar region and an arc-shaped corner region that are connected to each other. The second direction is parallel to the stacking direction of the first electrode in the planar region.

23. A battery device, characterized in that, It includes at least two battery cells according to any one of claims 1 to 22.

24. An electrical appliance, characterized in that, Includes a battery cell according to any one of claims 1 to 22 or a battery device according to claim 23, wherein the battery cell or the battery device is used to store or provide electrical energy.

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