Electrode assemblies, battery cells, batteries, and power consumption devices

Abstract

Embodiments of the present application provide an electrode assembly, a battery cell, a battery, and an electric power consuming device. The electrode assembly includes a first electrode plate including a plurality of first laminated portions and at least one first bending portion. Here, the first bending portion includes a plurality of first scores arranged along a second direction, the second direction being the extending direction of the first bending portion. The plurality of first scores include a first edge score located at both ends of the first electrode plate along the second direction and a first central score located in a central region of the first electrode plate. The length of the first edge score along the second direction is greater than the length of the first central score along the second direction. The electrode assembly, battery cell, battery, and electric power consuming device according to the embodiments of the present application can improve the processing efficiency and the yield of the electrode assembly.

Description

Technical Field

[0001] This application relates to the field of battery technology, and particularly to electrode assemblies, battery cells, batteries, and power-consuming devices.

Background Art

[0002] With the continuous progress of battery technology, various new energy industries using batteries as energy storage devices are developing rapidly. In the development of battery technology, not only improving the performance of batteries, but also improving safety and processing efficiency are issues that cannot be ignored. Therefore, how to improve the processing efficiency and safety of batteries is an issue to be solved in the process of battery technology development.

Summary of the Invention

Problems to be Solved by the Invention

[0003] Embodiments of this application provide an electrode assembly, a battery cell, a battery, and a power-consuming device that can improve the processing efficiency and yield rate of the electrode assembly.

Means for Solving the Problems

[0004] According to a first aspect, an electrode assembly is provided, including a first electrode plate including a plurality of first stacked portions and at least one first bending portion, the plurality of the first stacked portions being stacked and provided along a first direction, the first bending portion being used to connect two of the first stacked portions, the first electrode plate being arranged to be bent at the first bending portion, the first direction being perpendicular to the first stacked portion, wherein the first bending portion includes a plurality of first scores arranged along a second direction, the second direction being the extending direction of the first bending portion, the plurality of the first scores including a first edge score located at both ends of the first electrode plate along the second direction and a first central score located in a central region of the first electrode plate, and the length of the first edge score along the second direction is greater than the length of the first central score along the second direction.

[0005] Accordingly, the electrode assembly of the embodiment of the present application can achieve positioning of the first bent portion by the plurality of first scores, reduce misalignment at the bent portion of the first electrode plate, and the plurality of first scores can also reduce the difficulty of bending, reduce resistance when bending, and improve the processing efficiency of the electrode assembly. Furthermore, considering that when the first bent portion is bent, the resistance at both edge positions along the second direction of the first electrode plate is greater than the resistance at the center position of the first electrode plate, and that the variation of the fold at the edge position of the first electrode plate is greater, by setting the length of the first edge score along the second direction to be greater than the length of the first center score along the second direction, the resistance at the edge position of the first electrode plate can be further reduced, the variation can be reduced, the probability of misalignment when the first electrode plate is bent can be further reduced, and the processing efficiency and yield rate of the electrode assembly can be improved.

[0006] In some embodiments, along the first direction, the plurality of first scores are located in the middle of the first bend, thereby more accurately positioning the first electrode plate when it is bent along the plurality of first scores, minimizing electrode plate displacement and improving the processing efficiency and yield of the electrode assembly.

[0007] In some embodiments, the length of the first edge score along the second direction is three times or more the length of the first central score along the second direction, and / or the length of the first edge score along the second direction is five times or less the length of the first central score along the second direction.

[0008] If the length of the first edge score along the second direction is less than three times the length of the first central score along the second direction, the dimensions of the first edge score are too small, and it is not possible to effectively reduce the resistance of the edge region of the first electrode plate during the bending process, thereby not being able to effectively improve the processing efficiency of the electrode assembly. If the length of the first edge score along the second direction is greater than five times the length of the first central score along the second direction, the dimensions of the first edge score are too large, and it reduces the structural strength of the first electrode plate, affecting the processing yield of the electrode assembly.

[0009] In some embodiments, the plurality of first scores include a plurality of first central scores having equal lengths along the second direction and / or equal spacing along the second direction.

[0010] In this way, the lengths of multiple first central scores are equal, reducing the number of times the dimensional accuracy of different first central scores needs to be adjusted, thereby lowering the difficulty of processing. The spacing between multiple first central scores is equal, and the first central scores are distributed relatively uniformly along the second direction, so that a uniform force is applied to the central region of the first electrode plate along the second direction, making it easy to bend, reducing the difficulty of processing the electrode assembly, and improving the processing efficiency and yield rate of the electrode assembly.

[0011] In some embodiments, the end of the first electrode plate along the second direction includes a tab, and the length of the first edge score near the tab along the second direction is less than the length of the first edge score away from the tab along the second direction.

[0012] In the manufacturing process, considering that the thickness of the edge of the first electrode plate near the tab is generally smaller than the thickness of the edge of the first electrode plate away from the tab, the length of the first edge score near the tab along the second direction is set to be smaller than the length of the first edge score away from the tab along the second direction. This allows the resistance to bending the first electrode plate at the edge away from the tab to be reduced more effectively by the first edge score away from the tab, thereby reducing the difficulty of manufacturing the electrode assembly and improving the manufacturing efficiency and yield rate of the electrode assembly.

[0013] In some embodiments, the range of the ratio between the distance between the first edge score and the corresponding end of the first plate along the second direction and the length of the first plate along the second direction is [0.008, 0.02].

[0014] If the ratio is too small, the distance between the first edge score and the corresponding edge of the first electrode plate along the second direction will be too small, resulting in insufficient strength in the region between the first edge score and the edge of the first electrode plate. This will reduce the structural strength of the first electrode plate, affecting the processing efficiency and performance of the electrode assembly. It will also increase the processing accuracy requirements for the corresponding first edge score, making processing more difficult and disadvantageous to the processing efficiency of the electrode assembly. Therefore, the ratio must not be too small. Conversely, if the ratio is too large, the distance between the first edge score and the corresponding edge of the first electrode plate along the second direction will be relatively too large, affecting the effect of the first edge score in reducing the bending resistance of the first electrode plate edge. This will prevent the difficulty of bending the electrode assembly from being effectively reduced and disadvantageous to the processing efficiency of the electrode assembly. Therefore, the ratio must not be too large.

[0015] In some embodiments, the distance between the first edge score and the adjacent first central score is in the range of [1 mm, 10 mm]. If the distance is too large, i.e., if the distance between the first edge score and the provided first central score is relatively large, the region between the first edge score and the adjacent first central score will still experience relatively high resistance during the bending process, making it difficult to effectively reduce the resistance during the bending process of the electrode assembly and thus detrimental to improving the processing efficiency of the electrode assembly. Conversely, if the distance is too small, i.e., if the distance between the first edge score and the provided first central score is relatively small, the structural strength of the region between the first edge score and the provided first central score will be too low, affecting the structural strength of the first electrode plate and the structural strength of the electrode assembly. Furthermore, the processing accuracy requirements for the first edge score and the adjacent first central score will be relatively high, increasing the difficulty of processing the electrode assembly and affecting the processing efficiency of the electrode assembly.

[0016] In some embodiments, the first score is a through hole, or the first score is a groove. When the first score is a through hole, it is easier to process and significantly reduces resistance during the bending process, improving the processing efficiency of the electrode assembly. When the first score is a groove, it reduces resistance during the bending process and also reduces the loss of structural strength of the first electrode plate of the electrode assembly.

[0017] In some embodiments, the first electrode plate includes a plurality of first bends with different bending directions. By bending in different directions, a stacked electrode assembly is formed, and the structure is simple and easy to implement.

[0018] In some embodiments, the plurality of first bends include two first bends with opposite bending directions, and the dimensions of the first scores provided in the two first bends along the bending direction are equal, which makes the force applied to the plurality of first bends bent along different bending directions more uniform, resulting in a more uniform electrode assembly, reducing misalignment between different first laminates, and improving the processing efficiency and yield of the electrode assembly.

[0019] In some embodiments, the first electrode plate includes a plurality of first bends, the bending direction of the plurality of first bends is the same, and the dimension along the bending direction of the first score provided in the first bends closer to the center of the electrode assembly is smaller than the dimension along the bending direction of the first score provided in the first bends further away from the center of the electrode assembly.

[0020] Considering that the arc length along the bending direction of the first bend located inside the electrode assembly is relatively small, i.e., the radius of curvature is relatively small, while the arc length along the bending direction of the first bend located outside the electrode assembly is relatively large, i.e., the radius of curvature is relatively large, meaning that the arc length along the bending direction of the first bend gradually increases from the inside to the outside of the electrode assembly, by setting accordingly that the dimension along the bending direction of the first score provided in the first bend located closer to the center of the electrode assembly is smaller than the dimension along the bending direction of the first score provided in the first bend located further away from the center of the electrode assembly, the dimension of the first score in the first bend with a relatively small arc length can be made small, and the dimension of the first score in the first bend with a relatively large arc length can be made large, making it easier to process, improving the structural strength of the electrode assembly, and reducing the problem of the local strength of the electrode assembly being too low.

[0021] In some embodiments, the electrode assembly further includes a plurality of second electrodes having opposite polarity to the first electrode, and the plurality of second electrodes and the plurality of first laminates are arranged in an alternating stack along the first direction. In this way, the second electrodes do not need to be bent during the bending process of the electrode assembly, reducing the number of layers to be bent and easing the difficulty of bending the electrode assembly.

[0022] In some embodiments, along a third direction, the first bend corresponds to at least one second electrode plate, along the first direction, the dimension of the first score is less than or equal to the dimension of the corresponding at least one second electrode plate, and the third direction is perpendicular to the first and second directions. By setting the dimension of the first score along the first direction to be less than or equal to the dimension of the corresponding at least one second electrode plate along the first direction, the second electrode plate is not exposed from the first score, the deposition of active material caused by the first score being too large can be reduced, and the impact on the performance of the electrode assembly can also be reduced.

[0023] In some embodiments, the electrode assembly further includes a second electrode plate of opposite polarity to the first electrode plate, and the first and second electrode plates are wound around a winding shaft. This reduces the process of repeatedly cutting the second electrode plate before winding, thereby accelerating the manufacturing process of the electrode assembly.

[0024] In some embodiments, the second electrode plate includes a plurality of second laminates and at least one second bent portion, the second bent portion being used to connect two adjacent second laminates, the second bent portion including a plurality of second scores arranged along the second direction, the plurality of second scores including second edge scores located at both ends of the second electrode plate along the second direction and a second central score located in the central region of the second electrode plate, the length of the second edge scores along the second direction being greater than the length of the second central score along the second direction.

[0025] The second bending portion includes a plurality of second scores arranged along the second direction, and the positioning of the second bending portion is realized by the plurality of second scores, which can reduce the deviation at the bending position of the second pole plate and reduce the deviation between different pole plates of the electrode assembly. Also, the plurality of second scores can reduce the difficulty of bending, reduce the resistance during bending, and improve the processing efficiency of the electrode assembly. Further, when the second bending portion is bent, the resistance at the edge positions of both ends of the second pole plate along the second direction is greater than the resistance at the central position of the second pole plate, and considering that the variation of the fold at the edge position of the second pole plate is greater, by setting the length of the second edge score along the second direction to be greater than the length of the second central score along the second direction, the resistance at the edge position of the second pole plate can be further reduced, the variation can be decreased, the probability of deviation when the second pole plate is bent can be further reduced, the possibility of ineffectiveness of the electrode assembly can be decreased, and the processing efficiency and the yield rate of the electrode assembly can be improved.

[0026] In some embodiments, the dimension along the bending direction of the score provided on the bending portion closer to the center of the electrode assembly among the plurality of the first bending portions and at least one of the second bending portions is smaller than the dimension along the bending direction of the score provided on the bending portion away from the center of the electrode assembly.

[0027] Along the radial direction from the inside to the outside of the electrode assembly, the arc lengths of the first bending portion of the first electrode plate and the second bending portion of the second electrode plate gradually increase, that is, the bending radius gradually increases. Accordingly, by setting the dimensions along the bending direction of the first score and the second score to also gradually increase along the radial direction from the inside to the outside of the electrode assembly, the dimensions of the score provided at the bending portion with a relatively small arc length can also be relatively small, and the dimensions of the score provided at the bending portion with a relatively large arc length can also be large. This makes it easy to process, improves the structural strength of the electrode assembly, and can also reduce the problem that the local strength of the electrode assembly is too low.

[0028] In some embodiments, the second electrode plate is a positive electrode plate, which can also reduce the influence on the performance of the electrode assembly.

[0029] In some embodiments, the positive electrode plate includes a positive electrode active material layer, and the material of the positive electrode active material layer employs at least one of Prussian blue-based sodium ion positive electrode materials, layered oxide sodium ion positive electrode materials, and polyanion sodium materials. The electrode assembly and the battery cell formed by adopting such a positive electrode active material layer have better high-temperature resistance performance and reduce the possibility of explosion of the battery cell at high temperatures.

[0030] In some embodiments, the first electrode plate is a negative electrode plate, which can also reduce the influence on the performance of the electrode assembly.

[0031] In some embodiments, the negative electrode plate includes a negative electrode current collector whose surface is not coated with a negative electrode active material. In this way, the overall thickness of the negative electrode plate is reduced, and the weight of the formed electrode assembly is relatively light and the volume is relatively small. Or when the overall thickness of the negative electrode plate is reduced, the thickness of the positive electrode plate can be increased. For example, the thickness of the positive electrode active material layer of the positive electrode plate can be increased, and the energy density of the battery cell including the electrode assembly can be increased.

[0032] According to a second embodiment, a battery cell is provided that includes the electrode assembly described in the first embodiment.

[0033] According to a third aspect, a battery is provided that includes a plurality of battery cells, each including the electrode assembly described in the first aspect.

[0034] According to a fourth aspect, a power consumption device is provided which includes an electrode assembly as described in the first aspect and a battery for providing power.

[0035] In some embodiments, the power-consuming device is a vehicle, ship, or spacecraft. The present invention provides, for example, the following items: (Item 1) The first electrode plate (31) includes a plurality of first laminated portions (312) and at least one first bent portion (311), wherein the plurality of first laminated portions (312) are arranged in a stack along a first direction, the first bent portion (311) is used to connect two of the first laminated portions (312), the first electrode plate (31) is arranged to be bent at the location of the first bent portion (311), and the first direction is perpendicular to the first laminated portions (312). Hereinafter, the first bent portion (311) includes a plurality of first scores (313) arranged along a second direction, the second direction being the direction of extension of the first bent portion (311), and the plurality of first scores (313) include first edge scores (3131) located at both ends of the first electrode plate (31) along the second direction, and first central scores (3132) located in the central region of the first electrode plate (31), wherein the length of the first edge scores (3131) along the second direction is greater than the length of the first central scores (3132) along the second direction, in an electrode assembly. (Item 2) The electrode assembly according to item 1, wherein, along the first direction, the plurality of first scores (313) are located in the middle of the first bent portion (311). (Item 3) The length of the first edge score (3131) along the second direction is three times or more the length of the first central score (3132) along the second direction, and / or The electrode assembly according to item 1 or 2, wherein the length of the first edge score (3131) along the second direction is no more than five times the length of the first central score (3132) along the second direction. (Item 4) The electrode assembly according to any one of items 1 to 3, wherein the plurality of first scores (313) include a plurality of first central scores (3132) having equal lengths along the second direction and / or equal spacing along the second direction. (Item 5) The electrode assembly according to any one of items 1 to 4, wherein the end of the first electrode plate (31) along the second direction includes a tab (222), and the length of the first edge score (3131) near the tab (222) along the second direction is less than the length of the first edge score (3131) away from the tab (222) along the second direction. (Item 6) The electrode assembly according to any one of items 1 to 5, wherein the range of the ratio between the distance between the first edge score (3131) and the corresponding end of the first electrode plate (31) along the second direction and the length of the first electrode plate (31) along the second direction is [0.008, 0.02]. (Item 7) The electrode assembly according to any one of items 1 to 6, wherein the range of the distance between the first edge score (3131) and the adjacent first central score (3132) is [1 mm, 10 mm]. (Item 8) The first score (313) is a through hole, or, The first score (313) is a groove, as described in any one of items 1 to 7 of the electrode assembly. (Item 9) The electrode assembly according to any one of items 1 to 8, wherein the first electrode plate (31) includes a plurality of first bent portions (311) with different bending directions. (Item 10) The electrode assembly according to item 9, wherein the plurality of first bends (311) include two first bends (311) with opposite bending directions, and the dimensions of the first scores (313) provided on the two first bends (311) along the bending direction are equal. (Item 11) The first electrode plate (31) includes a plurality of first bent portions (311), and the bending direction of the plurality of first bent portions (311) is the same. The electrode assembly according to any one of items 1 to 8, wherein the dimension along the bending direction of the first score (313) provided on the first bent portion (311) closer to the center of the electrode assembly is smaller than the dimension along the bending direction of the first score (313) provided on the first bent portion (311) further away from the center of the electrode assembly. (Item 12) The electrode assembly is The electrode assembly according to any one of items 9 to 11, further comprising a plurality of second plates (32) having opposite polarity to the first plate (31), wherein the plurality of second plates (32) and the plurality of first laminated portions (312) are arranged alternately in a first direction. (Item 13) Along the third direction, the first bent portion (311) corresponds to at least one second electrode plate (32), The electrode assembly according to item 12, wherein, along the first direction, the dimension of the first score (313) is less than or equal to the dimension of the corresponding at least one second electrode plate (32), and the third direction is perpendicular to the first and second directions. (Item 14) The electrode assembly is The electrode assembly according to any one of items 1 to 8, 11, further comprising a second electrode plate (32) of opposite polarity to the first electrode plate (31), wherein the first electrode plate (31) and the second electrode plate (32) are wound around a winding shaft. (Item 15) The second electrode plate (32) includes a plurality of second laminated portions (322) and at least one second bent portion (321), the second bent portion (321) being used to connect two adjacent second laminated portions (322), The electrode assembly according to item 14, wherein the second bent portion (321) includes a plurality of second scores (323) arranged along the second direction, the plurality of second scores (323) including second edge scores located at both ends of the second electrode plate (32) along the second direction and second central scores located in the central region of the second electrode plate (32), the length of the second edge scores along the second direction being greater than the length of the second central scores along the second direction. (Item 16) The electrode assembly according to item 15, wherein the dimension along the bending direction of the score provided in the bending portion of the at least one first bending portion (311) and the at least one second bending portion (321) that is closer to the center of the electrode assembly is smaller than the dimension along the bending direction of the score provided in the bending portion that is further away from the center of the electrode assembly. (Item 17) The electrode assembly according to any one of items 12 to 16, wherein the second electrode plate (32) is a positive electrode plate. (Item 18) The electrode assembly according to item 17, wherein the positive electrode plate includes a positive electrode active material layer (325), and the material of the positive electrode active material layer (325) includes at least one of a Prussian blue sodium ion positive electrode material, a layered oxide sodium ion positive electrode material, and a polyanion sodium material. (Item 19) The electrode assembly described in any one of items 1 to 18, wherein the first electrode plate (31) is a negative electrode plate. (Item 20) The electrode assembly according to item 19, wherein the negative electrode plate includes a negative electrode current collector (314) whose surface is not coated with a negative electrode active material. (Item 21) A battery cell including an electrode assembly as described in any one of items 1 through 20. (Item 22) A battery comprising multiple battery cells, each containing an electrode assembly as described in any one of items 1 through 20. (Item 23) It is a power-consuming device, A power-consuming device including an electrode assembly as described in any one of items 1 to 20, and a battery for supplying power to the power-consuming device. [Brief explanation of the drawing]

[0036] [Figure 1] This is a schematic diagram of the structure of a vehicle disclosed in one embodiment of the present application. [Figure 2] This is a schematic diagram of the disassembled structure of a battery disclosed in one embodiment of the present application. [Figure 3] This is a schematic diagram of the structure of multiple battery cells included in a battery disclosed in one embodiment of the present application. [Figure 4] This is a schematic diagram of the structure of a battery cell disclosed in one embodiment of the present application. [Figure 5] This is a schematic diagram of the exploded structure of a battery cell disclosed in one embodiment of the present application. [Figure 6] This is a schematic cross-sectional view of an electrode assembly disclosed in one embodiment of the present application. [Figure 7] This is a schematic cross-sectional view of another electrode assembly disclosed in one embodiment of the present application. [Figure 8] This is a schematic cross-sectional view of yet another electrode assembly disclosed in one embodiment of the present application. [Figure 9] This is a schematic diagram of the structure of the unfolded first electrode plate disclosed in one embodiment of the present application. [Figure 10] This is a schematic partial cross-sectional view of the first electrode plate disclosed in one embodiment of the present application. [Figure 11] This is a schematic partial cross-sectional view of the second electrode plate disclosed in one embodiment of the present application.

[0037] In drawings, the drawings are not drawn to the actual scale. [Modes for carrying out the invention]

[0038] Embodiments of the present application will be described in more detail below, in conjunction with the drawings and examples. The detailed descriptions and drawings in the following embodiments are used to illustrate the principles of the present application, but are not intended to limit the scope of the present application; that is, the present application is not limited to the embodiments described.

[0039] In the description of this application, unless otherwise specified, "multiple" means two or more, and directions or positional relationships indicated by terms such as "up," "down," "left," "right," "inside," and "outside" are merely for the purpose of easily explaining and simplifying the description of this application, and do not indicate or imply that the referred device or element necessarily has a specific direction or must be configured or operated in a specific direction, and therefore should not be understood as a limitation on this application. Furthermore, terms such as "first," "second," and "third" are used solely for explanatory purposes and should not be understood as indicating or implying relative importance. "Perpendicular" does not mean perpendicular in the strict sense, but perpendicular within a range of acceptable error. "Parallel" does not mean parallel in the strict sense, but parallel within a range of acceptable error.

[0040] The directional terms appearing in the following description all refer to the directions shown in the drawings and do not limit the specific structure of the present application. In the description of the present application, unless otherwise clearly specified and limited, the terms “attach,” “connect,” and “connect” should be understood in a broad sense, for example, they may be fixed connections, removable connections, integral connections, direct connections, or indirect connections through intervening materials. A person skilled in the art will be able to understand the specific meaning of the above terms in the present application depending on the specific situation.

[0041] In the embodiments of this application, the same reference numerals indicate the same component, and for the sake of brevity, detailed descriptions of the same component are omitted in different embodiments. It should be understood that the dimensions such as thickness, length, and width of various components in the embodiments of this application shown in the drawings, and the overall dimensions such as thickness, length, and width of the accumulating device, are for illustrative purposes only and do not constitute any limitation to this application.

[0042] In this application, the battery cell may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, and the embodiments of this application are not limited thereto. The battery cell may be cylindrical, flattened, rectangular, or have other shapes, and the embodiments of this application are not limited thereto. Generally, battery cells are classified into three types according to the packaging method: columnar battery cells, rectangular battery cells, and pouch battery cells, and the embodiments of this application are not limited thereto.

[0043] As referred to in the embodiments of this application, a battery refers to a single physical module containing one or more battery cells to provide higher voltage and capacity. For example, a battery referred to in this application may include a battery module or a battery pack. A battery generally includes a housing for packaging one or more battery cells. The housing can reduce the influence of liquids or other foreign matter on the charging and discharging of the battery cells.

[0044] A battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of the battery cell, active ions (e.g., lithium ions) are inserted and removed by moving back and forth between the positive and negative electrodes. The separator is placed between the positive and negative electrodes and can prevent short circuits between them while allowing active ions to pass through.

[0045] In some embodiments, the positive electrode may be a positive electrode plate, which may include a positive electrode current collector and a positive electrode active material provided on at least one surface of the positive electrode current collector.

[0046] As an example, the positive electrode current collector has two opposing surfaces in the thickness direction of itself, and the positive electrode active material is provided on one or two of the two opposing surfaces of the positive electrode current collector.

[0047] In some embodiments, the negative electrode may be a negative electrode plate, which may include a negative electrode current collector and a negative electrode active material provided on at least one surface of the negative electrode current collector.

[0048] As an example, the negative electrode current collector has two opposing surfaces in the thickness direction of itself, and the negative electrode active material is provided on one or two of the two opposing surfaces of the negative electrode current collector.

[0049] In some embodiments, the negative electrode can be made of foamed metal. The foamed metal may be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon. When foamed metal is used as the negative electrode plate, the surface of the foamed metal does not necessarily have to have negative electrode active material, although it may, of course, have negative electrode active material.

[0050] In some embodiments, the electrode assembly further includes a separator provided between the positive and negative electrodes.

[0051] In some embodiments, the separator is a separation membrane. The present application does not particularly limit the type of separation membrane, and any known porous separation membrane having good chemical and mechanical stability can be selected.

[0052] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is placed between the positive and negative electrodes and serves to transport ions and separate the positive and negative electrodes.

[0053] In some embodiments, the battery cell further includes an electrolyte that plays a role in conducting ions between the positive and negative electrodes. The present application does not specifically limit the type of electrolyte, and it may be selected according to the requirements. The electrolyte may be liquid, gel-like, or solid.

[0054] In some embodiments, the electrode assembly is a wound structure. The positive and negative plates are wound together as a wound structure.

[0055] In some embodiments, the electrode assembly has a stacked structure. In some embodiments, the electrode assembly is provided with tabs that can draw current from the electrode assembly. The tabs include a positive electrode tab and a negative electrode tab.

[0056] During the process of manufacturing electrode assemblies, when it is necessary to bend at least one electrode plate in the electrode assembly, for example, when bending the bending corner region of a wound electrode assembly, the applied force tends to be uneven, which can lead to misalignment between electrode plates of different layers. These misaligned electrode plates are prone to the deposition of active material, affecting the processing efficiency and yield rate of the electrode assembly.

[0057] Accordingly, embodiments of the present application provide an electrode assembly comprising a first electrode plate including a plurality of first laminates and at least one bent portion, wherein the plurality of first laminates are arranged in a first direction, the first direction being perpendicular to the first laminates. The first bent portion is used to connect two first laminates, and the first electrode plate can be bent at the first bent portion. The first bent portion includes a plurality of first scores arranged along a second direction, the second direction being the direction of extension of the first bent portion. The plurality of first scores enable positioning of the first bent portion and reduce misalignment at the bend of the first electrode plate, and the plurality of first scores can also reduce the difficulty of bending, reduce resistance when bending, and improve the processing efficiency of the electrode assembly.

[0058] Furthermore, the plurality of first scores include first edge scores located at both ends along the second direction of the first electrode plate, and further include a first central score located in the central region of the first electrode plate, and the length of the first edge score along the second direction is greater than the length of the first central score along the second direction. When the first bend is folded, the resistance at the edge positions at both ends along the second direction of the first electrode plate is greater than the resistance at the central position of the first electrode plate, and the variation in the fold at the edge positions of the first electrode plate is greater. By setting the length of the first edge score along the second direction to be greater than the length of the first central score along the second direction, the resistance at the edge positions of the first electrode plate can be further reduced, the variation can be reduced, the probability of misalignment when the first electrode plate is folded can be further reduced, the possibility of active material deposition can be reduced, and the processing efficiency and yield rate of the electrode assembly can be improved.

[0059] The technical solutions described in the embodiments of this application are applicable to various power-consuming devices that use batteries.

[0060] Power-consuming devices may include vehicles, mobile phones, portable devices, personal computers, steamships, spacecraft, electric toys, and power tools. Vehicles may be fuel-oil vehicles, gas vehicles, or new energy vehicles. New energy vehicles may be pure electric vehicles, hybrid vehicles, or range-extender vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, electric toys include stationary or mobile electric toys, such as game consoles, electric vehicle toys, electric steamship toys, and electric airplane toys, and power tools include metal cutting power tools, polishing power tools, mounted power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact electric drills, concrete piping, and electric planers. The embodiments of this application are not particularly limited to the above-mentioned power-consuming devices.

[0061] The following examples illustrate a case where the power-consuming device is a vehicle, for the sake of clarity.

[0062] For example, as shown in Figure 1, Figure 1 is a schematic diagram of the structure of a vehicle 1 of one embodiment of the present application, and the vehicle 1 may be a fuel oil vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or a range extender vehicle. A motor 40, a controller 30, and a battery 10 may be provided inside the vehicle 1, and the controller 30 is used to control the battery 10 to supply power to the motor 40. For example, the battery 10 may be provided at the bottom, front, or rear of the vehicle 1. The battery 10 may be used to supply power to the vehicle 1, for example, the battery 10 may be used as an operating power source for the vehicle 1's circuit system, for example, to meet the demands for starting the vehicle 1, navigation, and operating power consumption during driving. In another embodiment of the present application, the battery 10 may not only be an operating power source for the vehicle 1, but also as a driving power source for the vehicle 1, providing driving power to the vehicle 1 in place of or in place of fuel oil or natural gas.

[0063] To meet the demands of various power usages, a battery may contain multiple battery cells, which may be connected in series, in parallel, or in a series-parallel configuration, where series-parallel connection refers to a combination of series and parallel connections. The battery may also be called a battery pack. Selectively, multiple battery cells may first be connected in series, in parallel, or in a series-parallel configuration to form a battery module, and then multiple battery modules may be connected in series, in parallel, or in a series-parallel configuration to form a battery. In other words, multiple battery cells may directly constitute a battery, or they may first constitute a battery module, and then the battery module may constitute a battery.

[0064] For example, Figure 2 shows a schematic diagram of the structure of a battery 10 according to one embodiment of the present application, and the battery 10 may include a plurality of battery cells 20, and Figure 3 shows a schematic diagram of a plurality of battery cells 20 included in the battery 10. As shown in Figures 2 and 3, the battery 10 may further include a housing 11, the inside of which is a hollow structure, and the plurality of battery cells 20 are housed inside the housing 11. Figure 2 shows one possible embodiment of the housing 11 according to an embodiment of the present application, and as shown in Figure 2, the housing 11 may include two parts, which are referred to as a first part 111 and a second part 112, respectively, and the first part 111 and the second part 112 are engaged. The shapes of the first part 111 and the second part 112 may be determined according to the shape of the combination of battery modules 200, and at least one of the first part 111 and the second part 112 has one opening. For example, as shown in Figure 2, both the first portion 111 and the second portion 112 may be hollow rectangular parallelepipeds with only one open surface each, the opening of the first portion 111 and the opening of the second portion 112 facing each other, and the first portion 111 and the second portion 112 engage with each other to form a housing 11 having a closed chamber.

[0065] Furthermore, unlike the one shown in Figure 2, for example, one of the first portion 111 and the second portion 112 may be a hollow rectangular parallelepiped with an opening, while the other is a plate-like structure that caps the opening. For example, if the second portion 112 is a hollow rectangular parallelepiped with only one face being an opening, and the first portion 111 is a plate-like structure, then the first portion 111 is capped over the opening of the second portion 112 to form a housing 11 having a closed chamber for housing multiple battery cells 20. The multiple battery cells 20 are connected in parallel, in series, or in series-parallel and then combined before being placed inside the housing 11 formed by the engagement of the first portion 111 and the second portion 112.

[0066] Selectively, the battery 10 may further include other structures, which will not be described further here. For example, as shown in Figures 2 and 3, the battery 10 may further include busbar members 12 for realizing electrical connections between a plurality of battery cells 20, such as parallel, series, or series-parallel connections. Specifically, the busbar members 12 may realize electrical connections between the battery cells 20 by connecting to the electrode terminals 214 of the battery cells 20. Furthermore, the busbar members 12 may be fixed to the electrode terminals 214 of the battery cells 20 by welding. The power of the plurality of battery cells 20 can further be drawn through the housing 11 by a conductive mechanism.

[0067] Depending on the various power demands, the number of battery cells 20 in the battery 10 may be set to any value. Multiple battery cells 20 can be connected in series, parallel, or series-parallel to achieve a relatively large capacity or power. Since each battery 10 may contain a relatively large number of battery cells 20, the battery cells 20 may be divided into groups for easier installation, and each group of battery cells 20 constitutes a battery module. The number of battery cells 20 included in a battery module is not limited and may be set according to the demand.

[0068] Figure 4 is a schematic diagram of the structure of a battery cell 20 according to one embodiment of the present application, and Figure 5 is a schematic diagram of a partially exploded structure of a battery cell 20 according to one embodiment of the present application. For example, the battery cell 20 shown in Figure 5 may be any one of the battery cells 20 shown in Figures 2 to 4. As shown in Figures 4 and 5, the battery cell 20 according to the embodiment of the present application may include a case 21. Specifically, the case 21 may include a hollow casing 211 having at least one opening, a cover 212 for covering the opening of the casing, and an electrode assembly 22 housed within the case 21.

[0069] It should be understood that the casing 211 in the embodiments of the present application is a component for housing the electrode assembly 22, and the casing 211 may be a hollow structure with openings formed at one or more ends. For example, if the casing 211 is a hollow structure with an opening at one end, one cover 212 may be provided, and if the casing 211 is a hollow structure with openings formed at both opposing ends, two covers 212 may be provided, with each of the two covers 212 fitted over the openings at both ends of the casing 211.

[0070] The casing 211 may have various shapes, such as a cylinder, a rectangular parallelepiped, or other polyhedron. Exemplarily, as shown in Figures 4 and 5, embodiments of the present application primarily describe a case where the casing 211 is a rectangular parallelepiped structure and has a hollow structure with an opening at one end.

[0071] It should be understood that the cover 212 in the embodiment of the present application is a component that is fitted over the opening of the casing 211 to isolate the internal environment of the battery cell 20 from the external environment. The shape of the cover 212 may match the shape of the casing 211, as shown in Figures 4 and 5, the casing 211 has a rectangular parallelepiped structure, and the cover 212 has a rectangular plate-like structure that fits the casing 211.

[0072] In the embodiments of this application, the material of the casing 211 may vary, for example, it may be copper, iron, aluminum, steel, or an aluminum alloy. The material of the cover 212 may also vary, for example, it may be copper, iron, aluminum, steel, or an aluminum alloy. Selectively, the material of the cover 212 and the material of the casing 211 may be the same or different.

[0073] It should be understood that the battery cell 20 further includes electrode terminals 214. The electrode terminals 214 in the embodiments of the present application are electrically connected to an electrode assembly 22 inside the battery cell 20 and used to output power from the battery cell 20. As shown in Figures 4 and 5, the battery cell 20 may include at least two electrode terminals 214, which may include at least one positive electrode terminal 214a and at least one negative electrode terminal 214b, the positive electrode terminal 214a being used to be electrically connected to a positive tab 222a of the electrode assembly 22, and the negative electrode terminal 214b being used to be electrically connected to a negative tab 222b of the electrode assembly 22. The positive electrode terminal 214a and the positive tab 222a may be directly connected or indirectly connected, and the negative electrode terminal 214b and the negative tab 222b may be directly connected or indirectly connected. For example, the positive electrode terminal 214a may be electrically connected to the positive electrode tab 222a by a single connecting material, and the negative electrode terminal 214b may be electrically connected to the negative electrode tab 222b by a single connecting material.

[0074] In the battery cell 20, the electrode assembly 22 is a component that undergoes an electrochemical reaction within the battery cell 20. Depending on the actual usage requirements, one electrode assembly 22 may be provided within the casing 211, or multiple electrode assemblies 22 may be provided. For example, as shown in Figures 4 and 5, two electrode assemblies 22 are provided within the battery cell 20. The electrode assembly 22 may be cylindrical, a rectangular parallelepiped, or the like. If the electrode assembly 22 has a cylindrical structure, the casing 211 may also have a cylindrical structure. If the electrode assembly 22 has a rectangular parallelepiped structure, the casing 211 may also have a rectangular parallelepiped structure.

[0075] It should be understood that, as shown in Figures 4 and 5, the electrode assembly 22 includes tabs 222 and an electrode body portion 221, where the tabs 222 of the electrode assembly 22 may include a positive electrode tab 222a and a negative electrode tab 222b, the positive electrode tab 222a may be formed by laminating portions of the positive electrode plate where the positive electrode active material layer is not coated, the negative electrode tab 222b may be formed by laminating portions of the negative electrode plate where the negative electrode active material layer is not coated, and the electrode body portion 221 may be formed by laminating or winding the positive electrode plate and the negative electrode plate together.

[0076] Figures 6 to 8 show schematic cross-sectional views of electrode assemblies 22 of different embodiments of the present application. Although the electrode assemblies 22 shown in Figures 6 to 8 have different structures, the cross-sections shown are of the same direction of the electrode assembly 22. For example, the cross-sections in Figures 6 to 8 may be parallel to the end face where the tab 222 shown in Figure 5 is located. Figure 9 shows a partially unfolded schematic view of the first electrode plate 31 included in the electrode assembly 22 of an embodiment of the present application. For example, the first electrode plate 31 shown in Figure 9 may be a partially schematic view of any one of the electrode plates of the electrode assembly 22 shown in Figures 6 to 8.

[0077] As shown in Figures 6 to 9, the electrode assembly 22 of the embodiment of the present application includes a first electrode plate 31 comprising a plurality of first laminated portions 312 and at least one first bent portion 311, wherein the plurality of first laminated portions 312 are arranged in a stack along a first direction X, the first bent portion 311 is used to connect two of the first laminated portions 312, the first electrode plate 31 is arranged to be bent at the first bent portion 311, the first direction X is perpendicular to the first laminated portions 312, and here the first bend The portion 311 includes a plurality of first scores 313 arranged along a second direction Y, the second direction Y being the direction of extension of the first bent portion 311, the plurality of first scores 313 including first edge scores 3131 located at both ends of the first electrode plate 31 along the second direction Y, and first central score 3132 located in the central region of the first electrode plate 31, wherein the length L1 of the first edge score 3131 along the second direction Y is greater than the length L2 of the first central score 3132 along the second direction Y.

[0078] It should be understood that the first electrode plate 31 in the embodiment of the present application may be any one electrode plate of the electrode assembly 22, for example, the positive electrode plate or the negative electrode plate of the electrode assembly 22. For the sake of explanation, Figures 6 to 8 illustrate the case where the first electrode plate 31 is the negative electrode plate, but the embodiment of the present application is not limited to this.

[0079] As shown in Figures 6 to 8, in the electrode assembly 22, the first laminated portion 312 in the embodiment of the present application is a relatively flat region of the first electrode plate 31 of the electrode assembly 22, while the first bent portion 311 is a curved region of the first electrode plate 31 of the electrode assembly 22. Specifically, in the unfolded first electrode plate 31 shown in Figure 9, the first laminated portion 312 and the first bent portion 311 are connected to each other and spaced apart, that is, two first bent portions 311 are connected to both ends of each first laminated portion 312, and two first laminated portions 312 are connected to both ends of each first bent portion 311. When assembling the electrode assembly 22, the first electrode plate 31 is bent at the first bending portion 311, and the multiple first stacked portions 312 are stacked along the first direction X to form the electrode assembly 22, where the first direction is the direction perpendicular to the first stacked portions 312.

[0080] It should be understood that the first bent portion 311 of the embodiment of the present application includes a plurality of first scores 313 arranged along a second direction Y. Here, as shown in Figure 9, the second direction Y is the direction of extension of the first bent portion 311, that is, the second direction Y is perpendicular to the side on which the tab 222 of the first electrode plate 31 is located, that is, perpendicular to the end face on which the tab 222 of the electrode assembly 22 is located, that is, the second direction Y is the width direction of the first electrode plate 31. And the second direction Y is perpendicular to the first direction X.

[0081] In the embodiments of the present application, the plurality of first scores 313 include first edge scores 3131 located at both ends of the first electrode plate 31 along the second direction Y. Specifically, the second direction Y in the embodiments of the present application includes the vertically upward and vertically downward directions as shown in Figure 9, and the ends of the first electrode plate 31 along the second direction Y include the upper edge and the lower edge of the first electrode plate 31, and therefore the plurality of first scores 313 include at least one first edge score 3131 located at the upper edge and / or at least one first edge score 3131 located at the lower edge.

[0082] Furthermore, if the plurality of first scores 313 include a plurality of first edge scores 3131, the length L1 of the first edge score 3131 along the second direction Y in the embodiment of the present application may refer to the average, minimum, or maximum value of the lengths of the plurality of first edge scores 3131 along the second direction Y. For example, as shown in Figure 9, if the plurality of first scores 313 include two first edge scores 3131, and the length of the upper first edge score 3131 along the second direction Y is L11, and the length of the lower first edge score 3131 along the second direction Y is L12, then the length L1 of the first edge score 3131 along the second direction Y in the embodiment of the present application may be the minimum value of lengths L11 and L12, but the embodiment of the present application is not limited thereto.

[0083] Similar to the first edge score 3131, the plurality of first scores 313 in the embodiments of the present application may include at least one first central score 3132 located in the central region of the first electrode plate 31. If the plurality of first scores 313 includes a plurality of first central scores 3132, the length L2 of the first central score 3132 along the second direction Y in the embodiments of the present application may refer to the average, minimum, or maximum length of the plurality of first central scores 3132 along the second direction Y. For example, as shown in Figure 9, if the plurality of first scores 313 include five first central scores 3132, and the lengths of the five first central scores 3132 along the second direction Y are L21, L22, L23, L24, and L25 respectively from top to bottom, then the length L2 of the first central score 3132 along the second direction Y in the embodiment of the present application may be the maximum value among lengths L21 to L25, but the embodiment of the present application is not limited thereto.

[0084] Accordingly, in the embodiment of the present application, the first bent portion 311 includes a plurality of first scores 313 arranged along a second direction Y, the plurality of first scores 313 enabling the positioning of the first bent portion 311, reducing misalignment at the bent portion of the first electrode plate 31, and reducing misalignment between different electrode plates of the electrode assembly 22. Furthermore, the plurality of first scores 313 can also reduce the difficulty of bending, reduce resistance when bending, and improve the processing efficiency of the electrode assembly 22. Furthermore, when the first bent portion 311 is bent, the resistance at the edge positions at both ends of the first electrode plate 31 along the second direction Y is greater than the resistance at the center of the first electrode plate 31, and the variation in the fold at the edge positions of the first electrode plate 31 is greater. Therefore, by setting the length L1 of the first edge score 3131 along the second direction Y to be greater than the length L2 of the first center score 3132 along the second direction Y, the resistance at the edge positions of the first electrode plate 31 is further reduced, the variation is reduced, the probability of misalignment when the first electrode plate 31 is bent is further reduced, the possibility of active material deposition or invalidation of the electrode assembly 22 is reduced, and the processing efficiency and yield rate of the electrode assembly 22 can be improved.

[0085] In the embodiments of the present invention, the plurality of first scores 313 are located in the middle of the first bent portion 311 along the first direction X. Specifically, as shown in Figures 6 to 9, the plurality of first scores 313 are located in the middle of the first bent portion 311 along the first direction X, or in the middle of the first bent portion 311 along the bending direction W, so that the positioning when bending the first electrode plate 31 along the plurality of first scores 313 is more accurate, the displacement of the electrode plate is reduced as much as possible, and the processing efficiency and yield rate of the electrode assembly 22 are improved.

[0086] It should be understood that the bending direction W of the embodiments of the present application may include a clockwise direction W1 and a counterclockwise direction W2, and as shown in Figures 6 to 9, the first electrode plate 31 may include a plurality of first bent portions 311 with the same or different bending directions. For example, for different types of electrode assemblies 22, the first electrode plate 31 may include first bent portions 311 all having the same bending direction, or the first electrode plate 31 may include first bent portions 311 with different bending directions, and the embodiments of the present application are not limited thereto.

[0087] It should be understood that the length L1 of the first edge score 3131 along the second direction Y in the embodiments of this application may be flexibly set according to the actual application. Furthermore, if the first bent portion 311 includes a plurality of first edge scores 3131, the lengths of the plurality of first edge scores 313 along the second direction Y may be equal or unequal, and the positions of the plurality of first edge scores 313 along the second direction Y may be flexibly set according to the actual application. Similarly, the length L2 of the first central score 3132 along the second direction Y in the embodiments of this application may also be flexibly set according to the actual application. Furthermore, if the first bent portion 311 includes a plurality of first central scores 3132, the lengths of the plurality of first central scores 3132 along the second direction Y may be equal or unequal, and the positions of the plurality of first central scores 3132 along the second direction Y may also be flexibly set according to the actual application. The following will be explained with examples, along with several specific embodiments.

[0088] Selectively, in one embodiment, the length L1 of the first edge score 3131 along the second direction Y is three times or more the length L2 of the first central score 3132 along the second direction Y, and / or the length L1 of the first edge score 3131 along the second direction Y is five times or less the length L2 of the first central score 3132 along the second direction Y. Specifically, if the length L1 of the first edge score 3131 along the second direction Y is less than three times the length L2 of the first central score 3132 along the second direction Y, the dimensions of the first edge score 3131 are too small, and the resistance of the edge region of the first electrode plate 31 during the bending process cannot be effectively reduced, and the processing efficiency of the electrode assembly 22 cannot be effectively improved. If the length L1 of the first edge score 3131 along the second direction Y is greater than five times the length L2 of the first central score 3132 along the second direction Y, the dimensions of the first edge score 3131 are too large, which reduces the structural strength of the first electrode plate 31 and affects the yield rate of the electrode assembly 22.

[0089] Selectively, in one embodiment, if a plurality of first scores 313 include a plurality of first central scores 3132, the lengths of the plurality of first central scores 3132 along the second direction Y are equal, and / or the spacing of the plurality of first central scores 3132 along the second direction Y is equal. Specifically, as shown in Figures 6 to 9, taking the example of a plurality of first scores 313 including five first central scores 3132, if the lengths of the five first central scores 3132 along the second direction Y are L21, L22, L23, L24, and L25 respectively, then the five first central scores 3132 may be set to satisfy the condition that the lengths L21, L22, L23, L24, and L25 are all equal. Furthermore, if the lengths of the intervals along the second direction Y between the five first central scores 3132 are D12, D23, D34, and D45, respectively, then the five first central scores 3132 may be set such that the lengths D12, D23, D34, and D45 are all equal.

[0090] In this way, by setting the lengths of multiple first central scores 3132 along the second direction Y to be equal, the number of times the dimensional accuracy of different first central scores 3132 needs to be adjusted can be reduced, thereby easing the difficulty of processing. Furthermore, by setting the spacing of multiple first central scores 3132 along the second direction Y to be equal, that is, by arranging the first central scores 3132 to be uniformly distributed along the second direction Y, a uniform force is applied to the central region of the first electrode plate 31 along the second direction Y, making it easier to bend, reducing the difficulty of processing the electrode assembly 22, and improving the processing efficiency and yield rate of the electrode assembly 22.

[0091] Selectively, in one embodiment, the end of the first electrode plate 31 along the second direction Y includes a tab 222, and the length L11 of the first edge score 3131 along the second direction Y near the tab 222 is smaller than the length L12 of the first edge score 3131 along the second direction Y away from the tab 222. Specifically, as shown in Figures 6 to 9, the length of the first edge score 3131 along the second direction Y near the tab 222 is L11, while the length of the first edge score 3131 along the second direction Y away from the tab 222 is L12.

[0092] Selectively, in one embodiment, the range of the ratio between the distance D2 between the first edge score 3131 and the corresponding end of the first electrode plate 31 along the second direction Y and the length D1 of the first electrode plate 31 along the second direction Y is [0.008, 0.02]. This range of value is verified by a large number of experiments. Specifically, as shown in Figures 6 to 9, when the plurality of first scores 313 include a plurality of first edge scores 3131, the distance D2 between the first edge score 3131 and the corresponding end of the first electrode plate 31 along the second direction Y in the embodiment of the present application may refer to the average, minimum, or maximum value of the distance between the plurality of first edge scores 3131 and the corresponding end of the first electrode plate 31 along the second direction Y. For example, as shown in Figure 9, if the plurality of first scores 313 include two first edge scores 3131, and the distance between the upper first edge score 3131 along the second direction Y and the upper edge of the first electrode plate 31 is D21, and the distance between the lower first edge score 3131 along the second direction Y and the lower edge of the first electrode plate 31 is D22, then the distance D2 between the first edge score 3131 in the embodiment of the present application and the corresponding end of the first electrode plate 31 along the second direction Y may be the minimum of D21 and D22, but the embodiment of the present application is not limited thereto.

[0093] If the ratio between distance D2 and length D1 is too small, for example, less than 0.008, the distance D2 between the first edge score 3131 and the corresponding edge of the first electrode plate 31 along the second direction Y will be too small, resulting in insufficient strength in the region between the first edge score 3131 and the edge of the first electrode plate 31. This will reduce the structural strength of the first electrode plate 31, affecting the processing efficiency and performance of the electrode assembly 22. Furthermore, it will increase the processing accuracy requirements for the corresponding first edge score 3131, making processing more difficult and thus unfavorable to the processing efficiency of the electrode assembly 22. Therefore, the ratio between distance D2 and length D1 must not be too small.

[0094] Conversely, if the ratio between distance D2 and length D1 is too large, for example, greater than 0.02, the distance D2 between the first edge score 3131 and the corresponding edge of the first electrode plate 31 along the second direction Y becomes relatively too large. This affects the effect of the first edge score 3131 in reducing the bending resistance of the edge of the first electrode plate 31, preventing the difficulty of bending the electrode assembly 22 from being effectively reduced, and thus being detrimental to the processing efficiency of the electrode assembly 22. Therefore, the ratio between distance D2 and length D1 should not be too large.

[0095] Selectively, the ratio between distance D2 and length D1 may be set according to the actual application. For example, the ratio between distance D2 and length D1 may be set to 0.008, 0.009, 0.01, 0.011, 0.012, 0.013, 0.014, 0.015, 0.016, 0.017, 0.018, 0.019, or 0.02.

[0096] Furthermore, the magnitude of the distance D2 between the first edge score 3131 of the embodiment of the present application and the corresponding end of the first electrode plate 31 along the second direction Y may also be set according to the actual application. For example, the range of the value of the distance D2 may be set to [1 mm, 30 mm], and this range of value has been verified by a large number of experiments so that the distance D2 is not too large or too small. Alternatively, for example, the distance D2 may be set to 1 mm, 3 mm, 5 mm, 8 mm, 10 mm, 13 mm, 15 mm, 18 mm, 20 mm, 23 mm, 25 mm, 28 mm or 30 mm.

[0097] The length D1 of the first electrode plate 31 along the second direction Y in the embodiment of the present application may be set according to the actual application. For example, the range of values ​​for length D1 may be set to [50 mm, 1200 mm], and this range of values ​​may be verified by a large number of experiments. Alternatively, for example, length D1 may be set to 50 mm, 100 mm, 150 mm, 200 mm, 250 mm, 300 mm, 350 mm, 400 mm, 450 mm, 500 mm, 550 mm, 600 mm, 650 mm, 700 mm, 750 mm, 800 mm, 850 mm, 900 mm, 950 mm, 1000 mm, 1100 mm, or 1200 mm.

[0098] Selectively, in one embodiment, the range of the distance D3 between a first edge score 3131 and an adjacent first central score 3132 is [1 mm, 10 mm]. This range of values ​​is verified by a large number of experiments. Specifically, as shown in Figures 6 to 9, if the plurality of first scores 313 include a plurality of first edge scores 3131, the distance D3 between a first edge score 3131 and an adjacent first central score 3132 in the embodiment of the present application may refer to the maximum, minimum, or average value of the distance between each of the plurality of first edge scores 3131 and the corresponding first central score 3132. For example, as shown in Figure 9, if the plurality of first scores 313 include two first edge scores 3131, and the distance between the upper first edge score 3131 along the second direction Y and an adjacent first central score 3132 is D31, and the distance between the lower first edge score 3131 along the second direction Y and an adjacent first central score 3132 is D32, then the distance D3 between the first edge score 3131 and the adjacent first central score 3132 in the embodiment of the present application may be the minimum of D31 and D32, but the embodiment of the present application is not limited thereto.

[0099] If the distance D3 is too large, that is, if the distance between the first edge score 3131 and the first central score 3132 is relatively large, the region between the first edge score 3131 and the adjacent first central score 3132 will still experience relatively high resistance during the bending process. This will prevent a good and effective reduction of the resistance during the bending process of the electrode assembly 22, which is detrimental to improving the processing efficiency of the electrode assembly 22. Therefore, the distance D3 should not be too large. Conversely, if the distance D3 is too small, that is, if the distance between the first edge score 3131 and the first central score 3132 is relatively small, the structural strength of the region between the first edge score 3131 and the first central score 3132 will be too low, affecting the structural strength of the first electrode plate 31 and the structural strength of the electrode assembly 22. Furthermore, the machining precision requirements for the first central score 3132 adjacent to the first edge score 3131 will be relatively high, increasing the difficulty of machining the electrode assembly 22 and affecting the machining efficiency of the electrode assembly 22. Therefore, the distance D3 must not be too small.

[0100] Selectively, the specific value of the distance D3 may be set according to the actual application. For example, the distance D3 may be specifically set to 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, or 10 mm.

[0101] In the embodiments of the present invention, the structure of the first score 313 may be flexibly configured according to the actual application. For example, as shown in Figures 6 to 9, the first score 313 is a through hole, which is easy to process and can greatly reduce resistance during the bending process, thereby improving the processing efficiency of the electrode assembly 22.

[0102] For example, the first score 313 is a groove. In this way, resistance during the bending process can be reduced, and the loss of structural strength of the first electrode plate 31 of the electrode assembly 22 can also be reduced.

[0103] If the first score 313 is a groove, the groove may be realized in various ways. For example, the groove may be realized by thinning a portion of the first electrode plate 31, in which case the thickness of the bottom wall of the groove is smaller than the thickness of the area of ​​the first electrode plate 31 other than the groove. Also, for example, the opening direction of the groove may be flexibly set according to the actual application, for example, the opening of the groove may face toward the center of the electrode assembly 22, or the opening may face away from the center of the electrode assembly 22, and the embodiments of the present application are not limited thereto.

[0104] Selectively, the types of the first edge score 3131 and the first central score 3132 included in the first score 313 of the embodiments of the present application may be the same or different. For example, the first edge score 3131 may be a through hole while the first central score 3132 is a groove, or both the first edge score 3131 and the first central score 3132 may be through holes, and the embodiments of the present application are not limited thereto.

[0105] The above describes the dimensions of the first score 313 of the embodiment of the present application, mainly with reference to the drawings. Below, the first score 313 of different types of electrode assemblies 22 will be described in detail with reference to the drawings.

[0106] In the embodiment of the present application, the first electrode plate 31 includes a plurality of first bent portions 311 with different bending directions W. Specifically, the first electrode plate 31 may be formed by employing the bending method shown in Figure 6, in which case the first electrode plate 31 includes a plurality of first bent portions 311 with different bending directions W. For example, the first electrode plate 31 includes a first bent portion 311 bent along a clockwise direction W1, as well as a first bent portion 311 bent along a counterclockwise direction W2. By bending in different directions, a stacked electrode assembly 22 is formed, and this structure is simple and easy to implement.

[0107] Selectively, the plurality of first bends 311 include two first bends 311 with opposite bending directions W, and the dimensions of the first scores 313 provided on the two first bends 311 along the bending direction W are equal. Specifically, as shown in Figure 6, here, taking as an example any one of the multiple first bent portions 311 that is bent along the clockwise direction W1, the dimension of the first bent portion 311 along the clockwise direction W1 is R1, and taking as an example any one of the multiple first bent portions 311 that is bent along the counterclockwise direction W2, the dimension of the first bent portion 311 along the counterclockwise direction W2 is R2. In this case, by setting the dimension R1 to be equal to R2, the force applied to the multiple first bent portions 311 that are bent along different bending directions W is made more uniform, the formed electrode assembly 22 is more uniform, the misalignment between different first laminated portions 312 is reduced, and the processing efficiency and yield rate of the electrode assembly 22 are improved.

[0108] In the embodiments of the present invention, the first electrode plate 31 includes a plurality of first bent portions 311, and the bending direction W of the plurality of first bent portions 311 is the same, that is, the first electrode plate 31 is always bent along the same bending direction W. For example, as shown in Figure 7 or Figure 8, the plurality of first bent portions 311 included in the first electrode plate 31 are all bent along the clockwise direction W1 to form a wound electrode assembly 22.

[0109] Selectively, the dimension along the bending direction W of the first score 313 provided on the first bending portion 311 close to the center of the electrode assembly 22 among the plurality of first bending portions 311 is smaller than the dimension along the bending direction W of the first score 313 provided on the first bending portion 311 away from the center of the electrode assembly 22. For example, as shown in FIG. 7, taking the right half of the first electrode plate 31 as an example, the first electrode plate 31 includes three first bending portions 311 in order from a position close to the center of the electrode assembly 22 in a direction away from the electrode assembly 22, and the first score 313 is provided on each of the first bending portions 311. In the direction from the inner first bending portion 311 to the outer first bending portion 311, the dimensions along the bending direction W of the first scores 313 of the three bending portions 311 are R11, R12, and R13 in order. The dimensions along the bending direction W of the first scores 313 of the three first bending portions 311 are set to satisfy R11 < R12 < R13.

[0110] The arc length along the bending direction W of the first bending portion 311 located inside the electrode assembly 22 is relatively small, that is, the bending radius is relatively small. On the other hand, the arc length along the bending direction W of the first bending portion 311 located outside the electrode assembly 22 is relatively large, that is, the bending radius is relatively large. That is, considering that the arc length along the bending direction W of the first bending portion 311 gradually increases from the inside to the outside of the electrode assembly 22, correspondingly, the dimension along the bending direction W of the first score 313 provided on the first bending portion 311 close to the center of the electrode assembly 22 among the plurality of first bending portions 311 is smaller than the dimension along the bending direction W of the first score 313 provided on the first bending portion 311 away from the center of the electrode assembly 22. By setting it like this, the dimension of the first score 313 of the first bending portion 311 with a relatively small arc length can also be relatively small, and the dimension of the first score 313 of the first bending portion 311 with a relatively large arc length can also be large. It is easy to process, the structural strength of the electrode assembly 22 can be improved, and the problem that the local strength of the electrode assembly 22 is too low can also be reduced.

[0111] In the embodiment of the present application, the electrode assembly 22 further includes a first electrode plate 31 and a plurality of second electrode plates 32 having opposite polarity, and the plurality of second electrode plates 32 and the plurality of first laminated portions 312 are arranged by alternately stacking them along a first direction X. Specifically, as shown in Figure 6 or Figure 7, although the processing method of the first electrode plate 31 is different, the electrode assembly 22 may include a plurality of second electrode plates 32, and the plurality of second electrode plates 32 may be arranged between the plurality of first laminated portions 312 using a stacking method. In this way, in the process of bending the electrode assembly 22, it is not necessary to bend the second electrode plates 32, reducing the number of layers to be bent and easing the difficulty of bending the electrode assembly 22.

[0112] Selectively, along a third direction Z, the first bend 311 corresponds to at least one second electrode plate 32, along a first direction X, the dimension L3 of the first score 313 is less than or equal to the dimension L4 of the corresponding at least one second electrode plate 32, and the third direction Z is perpendicular to the first direction X and the second direction Y. For example, taking as an example a first score 313 provided on any one first bend 311 in Figure 6, the dimension of the first score 313 along the first direction X is L3, and along the third direction Z, one second electrode plate 32 is provided corresponding to the first bend 311, and the dimension of the second electrode plate 32 along the first direction X is L4, in this case the dimension L3 is less than or equal to L4. Alternatively, if a multilayer second electrode plate 32 is provided along the third direction Z corresponding to the first bent portion 311, the dimension L3 is less than or equal to the total dimension of the multilayer second electrode plate 32 along the first direction X.

[0113] By setting the dimension L3 of the first score 313 along the first direction X to be less than or equal to the dimension L4 of the corresponding at least one second electrode plate 32 along the first direction X, the deposition phenomenon of active material caused by the dimension of the first score 313 being too large can be reduced, and the impact on the performance of the electrode assembly 22 can also be reduced.

[0114] In the embodiments of the present application, the electrode assembly 22 may be formed by winding in other ways. For example, the electrode assembly 22 further includes a first electrode plate 31 and a second electrode plate 32 of opposite polarity, wherein the first electrode plate 31 and the second electrode plate 32 are provided wound around a winding axis. Specifically, as shown in Figure 8, the electrode assembly 22 may be formed by winding the first electrode plate 31 and the second electrode plate 32, thereby reducing the process of repeatedly cutting the second electrode plate 32 before winding and accelerating the winding process.

[0115] It should be understood that the second electrode plate 32 in the embodiment of the present application may be the same as the first electrode plate 31, and the second electrode plate 32 may have multiple scores. Specifically, the second electrode plate 32 includes a plurality of second laminated portions 322 and at least one second bent portion 321, the second bent portion 321 being used to connect two adjacent second laminated portions 322. The plurality of second laminated portions 322 are arranged in a stack along a first direction X, and the second electrode plate 32 is positioned to be bent at the second bent portion 321.

[0116] Furthermore, the second bent portion 321 includes a plurality of second scores 323 arranged along a second direction Y, the plurality of second scores 323 including second edge scores located at both ends of the second electrode plate 32 along the second direction Y and a second central score located in the central region of the first electrode plate 31, wherein the length of the second edge scores along the second direction Y is greater than the length of the second central score along the second direction Y. Specifically, the plurality of second scores 323 provided in the second bent portion 321 of the second electrode plate 32 in the embodiment of the present application are similar to the plurality of first scores 313 provided in the first bent portion 311 of the first electrode plate 31, and are applied to the description of the first scores 313, and for the sake of brevity, will not be described further here.

[0117] In the embodiments of the present application, the second bending portion 321 includes a plurality of second scores 323 arranged along the second direction Y. The positioning of the second bending portion 321 is realized by the plurality of second scores 323, which can reduce the deviation at the bending position of the second electrode plate 32 and the deviation between different electrode plates of the electrode assembly 22. In addition, the plurality of second scores 323 can reduce the difficulty of bending, reduce the resistance during bending, and improve the processing efficiency of the electrode assembly 22. Further, when the second bending portion 321 is bent, the resistance at the edge positions of both ends of the second electrode plate 32 along the second direction Y is greater than the resistance at the central position of the second electrode plate 32, and considering that the variation of the folds at the edge positions of the second electrode plate 32 is greater, by setting the length of the second edge score along the second direction Y to be greater than the length of the second central score along the second direction Y, the resistance at the edge position of the second electrode plate 32 can be further reduced, the variation can be decreased, the probability of deviation when the second electrode plate 32 is bent can be further reduced, the deposition of the active material or the possibility of invalidation of the electrode assembly 22 can be decreased, and the processing efficiency and the yield rate of the electrode assembly 22 can be improved.

[0118] In the embodiments of the present application, the dimension along the bending direction W of the score provided on the bending portion closer to the center of the electrode assembly among the plurality of first bending portions 311 and at least one second bending portion 321 is smaller than the dimension along the bending direction W of the score provided on the bending portion away from the center of the electrode assembly. Specifically, taking the left half of the electrode assembly 22 shown in FIG. 8 as an example, in the direction radially outward from the center of the electrode assembly 22, the first electrode plate 31 and the second electrode plate 32 together include two first bending portions 311 and one second bending portion 321, and the dimensions along the bending direction W of the scores provided on the three bending portions are R21, R22, and R23 in sequence. The dimensions along the bending direction W of the scores of the three bending portions are set to satisfy R21 < R22 < R23.

[0119] Similarly, for the right half of the electrode assembly 22, the first electrode plate 31 and the second electrode plate 32 include a total of three first bends 311 and two second bends 321 in the radial direction outward from the center of the electrode assembly 22, and the dimensions of the scores provided in these five bends along the bending direction W also gradually increase along the radial direction from the inside outward of the electrode assembly 22.

[0120] Along the radial direction from the inside to the outside of the electrode assembly 22, the arc length of the first bent portion 311 of the first electrode plate 31 and the second bent portion 321 of the second electrode plate 32 gradually increases, i.e., the radius of curvature gradually increases. Accordingly, by setting the dimensions of the first score 313 and the second score 323 along the bending direction W to also gradually increase along the radial direction from the inside to the outside of the electrode assembly 22, the dimensions of the scores provided in bent portions with relatively small arc lengths can be made relatively small, and the dimensions of the scores provided in bent portions with relatively large arc lengths can be made relatively large. This makes it easier to process, improves the structural strength of the electrode assembly 22, and reduces the problem of the local strength of the electrode assembly 22 being too low.

[0121] It should be understood that the polarities of the first electrode plate 31 and the second electrode plate 32 in the embodiments of this application may be the same or opposite. For example, in the embodiments of this application, mainly when the first electrode plate 31 is the negative electrode plate, the problem of active material deposition can be reduced, and the influence on the performance of the electrode assembly 22 can also be reduced. Also, for example, in the embodiments of this application, mainly when the second electrode plate 32 is the positive electrode plate, the problem of active material deposition can be reduced, and the influence on the performance of the electrode assembly 22 can also be reduced.

[0122] Figure 10 shows a schematic cross-sectional view of the first electrode plate 31 in an embodiment of the present application. For example, Figure 10 may be a cross-sectional view of the first electrode plate 31 along the direction A to A' shown in Figure 9, and here, the case in which the first electrode plate 31 is a negative electrode plate is used as an example. Figure 11 shows a schematic cross-sectional view of the second electrode plate 32 in an embodiment of the present application. The direction of the cross-section is the same as the direction shown in Figure 10, and here, the case in which the second electrode plate 32 is a positive electrode plate is used as an example.

[0123] Selectively, the negative electrode plate includes a negative electrode current collector 314 whose surface is not coated with negative electrode active material. In this way, the overall thickness of the negative electrode plate is reduced, the weight and volume of the resulting electrode assembly 22 are relatively light, or if the overall thickness of the negative electrode plate is reduced, the thickness of the positive electrode plate can be increased, for example, by increasing the thickness of the positive electrode active material layer 325 of the positive electrode plate, thereby increasing the energy density of the battery cell 20 including the electrode assembly 22.

[0124] If the surface of the negative electrode current collector 314 is not selectively coated with a negative electrode active material, the negative electrode current collector 314 may be made of copper foil, or the surface of the copper foil may be coated with conductive carbon, and the embodiments of the present application are not limited thereto.

[0125] As shown in Figures 10 to 11, the positive electrode plate of the embodiment of the present application may include a positive electrode current collector 324 and positive electrode active material layers 325 provided on both sides of the positive electrode current collector 324. Here, the material of the positive electrode active material layer 325 of the embodiment of the present application may be flexibly set according to the actual application. For example, the material of the positive electrode active material layer 325 includes at least one of Prussian blue sodium ion positive electrode material, layered oxide sodium ion positive electrode material, and polyanion sodium material. The electrode assembly 22 and battery cell 20 formed by employing such a positive electrode active material layer 325 have better high-temperature resistance and reduce the possibility of explosion of the battery cell 20 at high temperatures.

[0126] Selectively, the electrode assembly 22 of the embodiments of the present application may further include a separation membrane 33, which may be located between a first electrode plate 31 and a second electrode plate 32. For example, the separation membrane 33 may be located between a positive electrode plate and a negative electrode plate to separate the positive electrode plate from the negative electrode plate. The material of the separation membrane 33 of the embodiments of the present application may be set according to the actual application, for example, the material of the separation membrane 33 may be an alumina ceramic coating layer and a polyvinylidene difluoride (PVDF) adhesive, and the embodiments of the present application are not limited thereto.

[0127] Accordingly, the electrode assembly 22 of the embodiment of the present application includes a first electrode plate 31 comprising a plurality of first laminated portions 312 and at least one bent portion 311, wherein the plurality of first laminated portions 312 are arranged in a stack along a first direction X, the first direction X being perpendicular to the first laminated portions 312. The first bent portion 311 is used to connect two first laminated portions 312, and the first electrode plate 31 can be bent at the first bent portion 311. The first bent portion 311 comprises a plurality of first scores 313 arranged along a second direction Y, the second direction Y being the direction of extension of the first bent portion 311. The multiple first scores 313 enable the positioning of the first bent portion 311, reducing misalignment at the bent portion of the first electrode plate 31. Furthermore, the multiple first scores 313 can reduce the difficulty of bending, decrease the resistance during bending, and improve the processing efficiency of the electrode assembly 22.

[0128] Furthermore, the plurality of first scores 313 include first edge scores 3131 located at both ends along the second direction Y of the first electrode plate 31, and further include a first central score 3132 located in the central region of the first electrode plate 31, wherein the length of the first edge score 3131 along the second direction Y is greater than the length of the first central score 3132 along the second direction Y. When the first bent portion 311 is bent, the resistance at the edge positions at both ends of the first electrode plate 31 along the second direction Y is greater than the resistance at the center position of the first electrode plate 31, and considering that the variation in the fold at the edge position of the first electrode plate 31 is greater, the length of the first edge score 3131 along the second direction Y is set to be greater than the length of the first center score 3132 along the second direction Y. This further reduces the resistance at the edge position of the first electrode plate 31, reduces the variation, further reduces the probability of misalignment when the first electrode plate 31 is bent, reduces the possibility of active material deposition, and improves the processing efficiency and yield rate of the electrode assembly 22.

[0129] While the present application has been described with reference to preferred embodiments, various improvements may be made, and components may be replaced with equivalents, provided that they do not deviate from the scope of the application. In particular, unless there is a structural conflict, each technical feature mentioned in each embodiment can be combined in any manner. The present application is not limited to the specific embodiments disclosed in the specification, but includes all technical ideas that fall within the claims.

Claims

1. The first electrode plate (31) includes a plurality of first laminated portions (312) and at least one first bent portion (311), wherein the plurality of first laminated portions (312) are arranged in a stack along a first direction, the first bent portion (311) is used to connect two of the first laminated portions (312), the first electrode plate (31) is arranged to be bent at the location of the first bent portion (311), and the first direction is perpendicular to the first laminated portions (312). Here, the first bent portion (311) includes a plurality of first scores (313) arranged along a second direction, the second direction being the direction of extension of the first bent portion (311), and the plurality of first scores (313) include first edge scores (3131) located at both ends of the first electrode plate (31) along the second direction, and first central scores (3132) located in the central region of the first electrode plate (31), the length of the first edge scores (3131) along the second direction being greater than the length of the first central scores (3132) along the second direction. An electrode assembly wherein the end of the first electrode plate (31) along the second direction includes a tab (222), and the length of the first edge score (3131) near the tab (222) along the second direction is less than the length of the first edge score (3131) away from the tab (222) along the second direction.

2. The electrode assembly according to claim 1, wherein, along the first direction, the plurality of first scores (313) are located in the middle portion of the first bent portion (311).

3. The length of the first edge score (3131) along the second direction is three times or more the length of the first central score (3132) along the second direction, and / or The electrode assembly according to claim 1, wherein the length of the first edge score (3131) along the second direction is no more than five times the length of the first central score (3132) along the second direction.

4. The electrode assembly according to claim 1, wherein the plurality of first scores (313) include a plurality of first central scores (3132) having equal lengths along the second direction and / or equal spacing along the second direction.

5. The electrode assembly according to claim 1, wherein the range of the ratio between the distance between the first edge score (3131) and the end of the first electrode plate (31) along the second direction and the length of the first electrode plate (31) along the second direction is [0.008, 0.02].

6. The electrode assembly according to claim 1, wherein the range of the distance between the first edge score (3131) and the adjacent first central score (3132) is [1 mm, 10 mm].

7. The first score (313) is a through hole, or The electrode assembly according to claim 1, wherein the first score (313) is a groove.

8. The first electrode plate (31) includes a plurality of first bent portions (311) with different bending directions, The electrode assembly according to any one of claims 1 to 7, wherein the plurality of first bent portions (311) include two first bent portions (311) with opposite bending directions, and the dimensions of the first scores (313) provided on the two first bent portions (311) along the bending direction are equal.

9. The first electrode plate (31) includes a plurality of first bent portions (311), and the bending direction of the plurality of first bent portions (311) is the same. The electrode assembly according to any one of claims 1 to 7, wherein the dimension along the bending direction of the first score (313) provided on the first bent portion (311) closer to the center of the electrode assembly is smaller than the dimension along the bending direction of the first score (313) provided on the first bent portion (311) further away from the center of the electrode assembly.

10. The electrode assembly is The electrode assembly according to claim 8, further comprising a plurality of second electrodes (32) having opposite polarity to the first electrode (31), wherein the plurality of second electrodes (32) and the plurality of first laminated portions (312) are arranged in an alternating stack along the first direction.

11. Along the third direction, the first bent portion (311) corresponds to at least one second electrode plate (32), The electrode assembly according to claim 10, wherein, along the first direction, the dimension of the first score (313) is less than or equal to the dimension of the corresponding at least one second electrode plate (32), and the third direction is perpendicular to the first and second directions.

12. The electrode assembly is The electrode assembly according to any one of claims 1 to 7, further comprising a second electrode plate (32) having the opposite polarity to the first electrode plate (31), wherein the first electrode plate (31) and the second electrode plate (32) are provided wound around a winding shaft.

13. The second electrode plate (32) includes a plurality of second laminated portions (322) and at least one second bent portion (321), the second bent portion (321) being used to connect two adjacent second laminated portions (322), The electrode assembly according to claim 12, wherein the second bent portion (321) includes a plurality of second scores (323) arranged along the second direction, the plurality of second scores (323) including second edge scores located at both ends of the second electrode plate (32) along the second direction and second central scores located in the central region of the second electrode plate (32), the length of the second edge scores along the second direction being greater than the length of the second central scores along the second direction.

14. The electrode assembly according to claim 13, wherein the dimension along the bending direction of the score provided in the bending portion of the at least one first bending portion (311) and the at least one second bending portion (321) that is closer to the center of the electrode assembly is smaller than the dimension along the bending direction of the score provided in the bending portion that is further away from the center of the electrode assembly.

15. The aforementioned second electrode plate (32) is a positive electrode plate, The electrode assembly according to claim 10, wherein the positive electrode plate includes a positive electrode active material layer (325), and the material of the positive electrode active material layer (325) includes at least one of a Prussian blue sodium ion positive electrode material, a layered oxide sodium ion positive electrode material, and a polyanion sodium material.

16. The first electrode plate (31) is a negative electrode plate, The electrode assembly according to any one of claims 1 to 7, wherein the negative electrode plate includes a negative electrode current collector (314) whose surface is not coated with a negative electrode active material.

17. A battery cell comprising the electrode assembly according to any one of claims 1 to 7.

18. A battery comprising a plurality of battery cells, each including an electrode assembly according to any one of claims 1 to 7.

19. It is a power-consuming device, A power-consuming device comprising an electrode assembly according to any one of claims 1 to 7, and a battery for supplying power to the power-consuming device.

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