Electrode assembly, battery cell, battery, and power consuming device

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] The present 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 the present 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 laminated portions and at least one first bending portion, the plurality of first laminated portions being laminated and provided along a first direction, the first bending portion being used to connect two of the first laminated portions, the first electrode plate being arranged to be bent at the first bending portion, the first direction being perpendicular to the first laminated 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 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 a length of the first edge score along the second direction is greater than a length of the first central score along the second direction.

[0005] Therefore, the electrode assembly of the embodiment of the present application can realize the positioning of the first bending portion by the plurality of first scores, reduce the deviation at the bending position of the first electrode plate, and the plurality of first scores can also reduce the difficulty of bending, reduce the resistance when being bent, and improve the processing efficiency of the electrode assembly. Further, when the first bending portion is bent, considering that the resistance at the edge positions of both ends of the first electrode plate along the second direction is greater than the resistance at the central position of the first electrode plate, and the variation of the crease 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 central score along the second direction, the resistance at the edge position of the first electrode plate can be further reduced, the variation can be decreased, the probability of deviation when the first electrode plate is bent can be further reduced, and the processing efficiency and the yield rate of the electrode assembly can be improved.

[0006] In some embodiments, along the first direction, the plurality of first scores are located at the middle part of the first bending portion, whereby when the first electrode plate is bent along the plurality of first scores, it can be positioned more accurately, the deviation of the electrode plate can be reduced as much as possible, and the processing efficiency and the yield rate of the electrode assembly can be improved.

[0007] In some embodiments, the length of the first edge score along the second direction is 3 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 5 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 dimension of the first edge score is too small to effectively reduce the resistance of the edge region of the first electrode plate during the bending process and cannot 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 dimension of the first edge score is too large, which reduces the structural strength of the first electrode plate and affects the processing yield of the electrode assembly.

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

[0010] In this way, the lengths of the plurality of first central scores are equal, reducing the number of times of adjusting the dimensional accuracy of different first central scores and reducing the processing difficulty. The intervals of the plurality of first central scores are equal, and the first central scores are relatively uniformly distributed along the second direction. A uniform force is applied along the second direction to the central region of the first electrode plate, making it easy to bend, reducing the processing difficulty of the electrode assembly, and improving the processing efficiency and yield 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 close to the tab along the second direction is smaller than the length of the first edge score away from the tab along the second direction.

[0012] In the processing process, considering that the thickness of the edge near the tab of the first electrode plate is generally smaller than the thickness of the edge away from the tab of the first electrode plate, by setting the length of the first edge score along the second direction near the tab to be smaller than the length of the first edge score along the second direction away from the tab, the first edge score away from the tab can more effectively reduce the resistance to bending the first electrode plate at the edge position away from the tab. That is, it reduces the difficulty of processing the electrode assembly and improves the processing efficiency and the qualified product rate of the electrode assembly.

[0013] In some embodiments, the range of the value of the ratio between the distance between the first edge score and the corresponding end of the first electrode plate along the second direction and the length of the first electrode 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 is too small, resulting in insufficient strength in the region between the first edge score and the edge of the first electrode plate, reducing the structural strength of the first electrode plate, affecting the processing efficiency and performance of the electrode assembly, and also increasing the requirements for the processing accuracy of the corresponding first edge score, increasing the processing difficulty, which is disadvantageous to the processing efficiency of the electrode assembly. Therefore, the ratio should not be too small. On the contrary, 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 is relatively too large, affecting the effect of reducing the bending resistance of the first electrode plate edge by the first edge score, and unable to effectively reduce the bending difficulty of the electrode assembly, which is disadvantageous to the processing efficiency of the electrode assembly. Therefore, the ratio should not be too large.

[0015] In some embodiments, the range of the value of the distance between the first edge score and the first central score adjacent thereto is [1 mm, 10 mm]. If the distance is too large, that is, when the distance between the first edge score and the first central score provided is relatively large, the resistance applied to the area between the first edge score and the adjacent first central score is still relatively large during the bending process, and the resistance during the bending process of the electrode assembly cannot be reduced well and effectively, which is disadvantageous for improving the processing efficiency of the electrode assembly. Conversely, if the distance is too small, that is, when the distance between the first edge score and the first central score provided is relatively small, the structural strength of the area between the first edge score and the first central score provided is too low, which affects the structural strength of the first electrode plate and the structural strength of the electrode assembly. And the requirement for the processing accuracy of the first central score adjacent to the first edge score is relatively high, which increases the difficulty of processing the electrode assembly and affects the processing efficiency of the electrode assembly.

[0016] In some embodiments, the first score is a through hole, or the first score is a concave groove. When the first score is a through hole, it is easy to process, and the resistance during the bending process can be extremely significantly reduced, and the processing efficiency of the electrode assembly can be improved. When the first score is a concave groove, the resistance during the bending process can be reduced, and the loss of the structural strength of the first electrode plate of the electrode assembly can also be reduced.

[0017] In some embodiments, the first electrode plate includes a plurality of the first bending portions with different bending directions. By being bent in different directions, a laminated electrode assembly is formed, and this structure is simple and easy to realize.

[0018] In some embodiments, the plurality of the first bending portions include two first bending portions with opposite bending directions, and the dimensions along the bending direction of the first score provided on the two first bending portions are equal, making the forces applied to the plurality of first bending portions bent along different bending directions more uniform, the formed electrode assembly more uniform, reducing the deviation between different first stacked portions, and improving the processing efficiency and the yield rate of the electrode assembly.

[0019] In some embodiments, the first electrode plate includes the plurality of the first bending portions, and the bending directions of the plurality of the first bending portions are the same. The dimension along the bending direction of the first score provided on the first bending portion closer to the center of the electrode assembly among the plurality of the first bending portions is smaller than the dimension along the bending direction of the first score provided on the first bending portion farther from the center of the electrode assembly.

[0020] Considering that the arc length along the bending direction of the first bending portion located inside the electrode assembly is relatively small, that is, the bending radius is relatively small, while the arc length along the bending direction of the first bending portion located outside the electrode assembly is relatively large, that is, the bending radius is relatively large, that is, the arc length along the bending direction of the first bending portion gradually increases from the inside to the outside of the electrode assembly, accordingly, by setting the dimension along the bending direction of the first score provided on the first bending portion closer to the center of the electrode assembly among the plurality of the first bending portions to be smaller than the dimension along the bending direction of the first score provided on the first bending portion farther from the center of the electrode assembly, the dimension of the first score of the first bending portion with a relatively small arc length can also be small, and the dimension of the first score of the first bending portion with a relatively large arc length can also be large, which is easy to process, can improve the structural strength of the electrode assembly, and can also reduce the problem that the local strength of the electrode assembly is too low.

[0021] In some embodiments, the electrode assembly further includes a plurality of second electrode plates having a polarity opposite to that of the first electrode plate, and the plurality of second electrode plates and the plurality of first stacked portions are alternately stacked along the first direction. In this way, in the process of bending the electrode assembly, it is not necessary to bend the second electrode plate, the number of bending layers is reduced, and the difficulty of bending the electrode assembly is alleviated.

[0022] In some embodiments, along a third direction, the first bending portion corresponds to at least one second electrode plate, and 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 direction and the second direction. In this way, 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, and it is possible to reduce the phenomenon of active material precipitation caused by the dimension of the first score being too large, and it is also possible to reduce the influence on the performance of the electrode assembly.

[0023] In some embodiments, the electrode assembly further includes a second electrode plate having a polarity opposite to that of the first electrode plate, and the first electrode plate and the second electrode plate are wound around a winding shaft. The process of repeatedly cutting the second electrode plate before winding can be reduced, and the processing process of the electrode assembly can be accelerated.

[0024] In some embodiments, the second electrode plate includes a plurality of second stacked portions and at least one second bending portion, the second bending portion is used to connect two adjacent second stacked portions, the second bending portion includes a plurality of second scores arranged along the second direction, the plurality of second scores include second edge scores located at both ends of the second electrode plate along the second direction and second central scores located in the central region of the second electrode plate, and the length of the second edge score along the second direction is 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 electrode plate and the deviation between different electrode 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 electrode plate along the second direction is greater than the resistance at the central position of the second electrode plate, and considering that the variation of the creases at the edge positions of the second electrode 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 electrode plate can be further reduced, the variation can be decreased, the probability of deviation when the second electrode plate is bent can be further reduced, the possibility of invalidation 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 first bending portions and at least one second bending portion 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 gradually increase along the radial direction from the inside to the outside of the electrode assembly, the dimensions of the score provided on the bending portion with a relatively small arc length can also be relatively small, and the dimensions of the score provided on 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 adopts 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 is increased. For example, the thickness of the positive electrode active material layer of the positive electrode plate is increased, and the energy density of the battery cell including the electrode assembly can be increased.

[0032] According to a second aspect, there is provided a battery cell including the electrode assembly described in the first aspect.

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

[0034] According to a fourth aspect, there is provided an electric power consuming device including a battery including the electrode assembly described in the first aspect and for providing electric power.

[0035] In some embodiments, the electric power consuming device is a vehicle, a ship or a spacecraft.

Brief Description of the Drawings

[0036]

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[0037] In the drawings, the drawings are not drawn to actual scale.

Embodiments for Carrying out the Invention

[0038] Hereinafter, the embodiments of the present application will be described in more detail in conjunction with the drawings and examples. The detailed description and drawings in the following examples are used to exemplarily explain the principle of the present application, but cannot be used to limit the scope of the present application. That is, the present application is not limited to the described embodiments.

[0039] In the description of the present application, unless otherwise specified, "a plurality" means two or more. The orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "inner", "outer", etc. is merely for facilitating the description of the present application and simplifying the description, and does not indicate or imply that the indicated device or element must have a specific orientation and must be configured or operated in a specific orientation. Therefore, it cannot be understood as a limitation to the present application. In addition, terms such as "first", "second", "third", etc. are merely used for the purpose of description and cannot be understood as indicating or implying relative importance. "Vertical" is not vertical in a strict sense, but vertical within an allowable error range. "Parallel" is not parallel in a strict sense, but parallel within an allowable error range.

[0040] The directional terms appearing in the following description are all 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 defined and limited, the terms "attach", "connect", and "couple" should be understood in a broad sense. For example, it may be a fixed connection, a removable connection, an integral connection, a direct connection, or an indirect connection through an intervening object. Those skilled in the art can understand the specific meaning of the above terms in the present application according to the specific situation.

[0041] In the embodiments of the present application, the same reference numerals denote the same members, and for the sake of brevity, in different embodiments, detailed descriptions of the same members are omitted. It should be understood that the dimensions such as the thickness, length, and width of various members in the embodiments of the present application shown in the drawings, and the dimensions such as the overall thickness, length, and width of the integrated device are merely illustrative descriptions and do not constitute any limitation to the present application.

[0042] In the present application, the battery cell may include a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery, a magnesium-ion battery, etc., and the embodiments of the present application are not limited thereto. The battery cell may be in the shape of a cylinder, a flat body, a cuboid, or other shapes, and the embodiments of the present application are not limited thereto either. Generally, battery cells are divided into three types: cylindrical battery cells, square battery cells, and pouch battery cells in a packaging manner, and the embodiments of the present application are not limited thereto either.

[0043] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells so as to provide a higher voltage and capacity. For example, the battery mentioned in the present application may include a battery module, a battery pack, etc. Generally, a battery includes a housing for packaging one or more battery cells. The housing can reduce the influence of liquid or other foreign substances on the charge and discharge of the battery cells.

[0044] Generally, a battery cell includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the process of charging and discharging the battery cell, active ions (for example, lithium ions) reciprocate between the positive electrode and the negative electrode for insertion and extraction. The separator is provided between the positive electrode and the negative electrode, which can play a role in preventing the short circuit between the positive and negative electrodes and allowing active ions to pass through.

[0045] In some embodiments, the positive electrode may be a positive electrode plate, and the positive electrode plate 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 surfaces facing each other in its own thickness direction, and the positive electrode active material is provided on either one or both of the two opposing surfaces of the positive electrode current collector.

[0047] In some embodiments, the negative electrode may be a negative electrode plate, and the negative electrode plate 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 surfaces facing each other in its own thickness direction, and the negative electrode active material is provided on either one or both of the two opposing surfaces of the negative electrode current collector.

[0049] In some embodiments, a foamed metal can be employed for the negative electrode. The foamed metal may be, for example, foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon. When the foamed metal is used as the negative electrode plate, the negative electrode active material may not be provided on the surface of the foamed metal, or of course, the negative electrode active material may be provided.

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

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

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

[0053] In some embodiments, the battery cell further includes an electrolyte that serves to conduct 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 demand. The electrolyte may be in a liquid, gel, or solid state.

[0054] In some embodiments, the electrode assembly has a wound structure. The positive electrode plate and the negative electrode plate are wound 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, and the tabs can draw current out of the electrode assembly. The tabs include a positive tab and a negative tab.

[0056] In the process of processing the electrode assembly, when it is necessary to bend at least one electrode plate in the electrode assembly, for example, taking the wound electrode assembly as an example, when bending the bent corner region of the wound electrode assembly, the problem that the applied force is uneven is likely to occur, leading to misalignment between different layers of electrode plates. The misaligned electrode plates are likely to have problems such as deposition of the active material, which affects the processing efficiency and the processing yield rate of the electrode assembly.

[0057] Therefore, the embodiments of the present application provide an electrode assembly, which includes a first electrode plate including a plurality of first stacked portions and at least one bent portion. The plurality of first stacked portions are stacked along a first direction, and the first direction is perpendicular to the first stacked portions. The first bent portion is used to connect two first stacked portions, 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, and the second direction is the extending direction of the first bent portion. The positioning of the first bent portion is realized by the plurality of first scores, and the deviation at the bending position of the first electrode plate can be reduced. In addition, the plurality of first scores can also reduce the difficulty of bending, reduce the resistance when being bent, and improve the processing efficiency of the electrode assembly.

[0058] Moreover, the plurality of first scores includes first edge scores located at both ends along the second direction of the first electrode plate, further includes 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 bending portion is bent, considering that 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 of the crease 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 central score along the second direction, the resistance at the edge position of the first electrode plate can be further reduced, the variation can be decreased, the probability of deviation when the first electrode plate is bent can be further reduced, the possibility of deposition of the active material can be decreased, and the processing efficiency and the yield rate of the electrode assembly can be improved.

[0059] The technical solutions described in the embodiments of the present application are all applicable to various power-consuming devices using batteries.

[0060] The power-consuming device may be a vehicle, a mobile phone, a portable device, a notebook computer, a steamship, a spacecraft, an electric toy, an electric tool, etc. The vehicle may be a fuel-powered vehicle, a gas-powered vehicle, or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle, a range extender vehicle, etc. The spacecraft includes airplanes, rockets, space shuttles, spaceships, etc. The electric toy includes stationary or mobile electric toys, such as game consoles, electric vehicle toys, electric steamship toys, and electric airplane toys. The electric tool includes metal cutting electric tools, grinding electric tools, mounting electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric drivers, electric hammers, impact electric drills, concrete vibrators, and electric cutters. The embodiments of the present application do not particularly limit the above power-consuming devices.

[0061] For the sake of easier explanation, the following embodiments will be described by taking the case where the power-consuming device is a vehicle as an example.

[0062] For example, as shown in FIG. 1, FIG. 1 is a schematic structural diagram of a vehicle 1 according to an embodiment of the present application. The vehicle 1 may be a fuel oil vehicle, a gas vehicle, or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or a range extender vehicle, etc. A motor 40, a controller 30, and a battery 10 may be provided inside the vehicle 1. The controller 30 is used to control the battery 10 to supply power to the motor 40. For example, the battery 10 is provided at the bottom, the front end, or the rear end 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 in the circuit system of the vehicle 1 as an operating power source of the vehicle 1. For example, it is used for the starting, navigation, and operating power consumption requirements during driving of the vehicle 1. In another embodiment of the present application, the battery 10 can not only be the operating power source of the vehicle 1, but also be used as the driving power source of the vehicle 1 to provide driving power to the vehicle 1 instead of, or partially instead of, fuel oil or natural gas.

[0063] To meet various power usage requirements, the battery may include a plurality of battery cells. Here, the plurality of battery cells may be connected in series, or in parallel, or in series-parallel connection. The series-parallel connection refers to a mixture of series connection and parallel connection. The battery may be referred to as a battery pack. Optionally, a plurality of battery cells are first connected in series, or in parallel, or in series-parallel connection to form a battery module, and then a plurality of battery modules are connected in series, or in parallel, or in series-parallel connection to form a battery. That is, a plurality of battery cells may directly form a battery, or first form a battery module, and then the battery module forms a battery.

[0064] For example, FIG. 2 shows a schematic structural diagram of a battery 10 according to an embodiment of the present application. The battery 10 may include a plurality of battery cells 20. FIG. 3 shows a schematic diagram of the plurality of battery cells 20 included in the battery 10. As shown in FIGS. 2 and 3, the battery 10 may further include a housing 11. The interior of the housing 11 has a hollow structure, and the plurality of battery cells 20 are accommodated within the housing 11. FIG. 2 shows one possible implementation form of the housing 11 according to the embodiment of the present application. As shown in FIG. 2, the housing 11 may include two parts, which are herein referred to as the first part 111 and the second part 112 respectively. 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 the battery modules 200. At least one of the first part 111 and the second part 112 has an opening. For example, as shown in FIG. 2, the first part 111 and the second part 112 may both be hollow rectangular parallelepipeds and each have only one face as the opening face. The opening of the first part 111 and the opening of the second part 112 are provided opposite to each other, and the first part 111 and the second part 112 are engaged with each other to form a housing 11 having a closed chamber.

[0065] Also for example, different from what is shown in FIG. 2, only one of the first part 111 and the second part 112 may be a hollow rectangular parallelepiped having an opening, and the other may be plate-shaped and be attached to the opening. For example, taking the case where the second part 112 is a hollow rectangular parallelepiped and has only one face as the opening face and the first part 111 is plate-shaped as an example, the first part 111 is attached to the opening of the second part 112 to form a housing 11 having a closed chamber for accommodating the plurality of battery cells 20. The plurality of battery cells 20 are connected in parallel with each other, or in series, or in series-parallel combination and then arranged within the housing 11 formed by engaging the first part 111 and the second part 112.

[0066] Optionally, the battery 10 may further include other structures, which will not be described further herein. For example, as shown in FIGS. 2 and 3, the battery 10 may further include a bus bar member 12 for realizing electrical connection between a plurality of battery cells 20, such as parallel connection, series connection, or series-parallel connection. Specifically, the bus bar member 12 may realize electrical connection between the battery cells 20 by connecting to the electrode terminals 214 of the battery cells 20. Further, the bus bar member 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 out through the housing 11 by a conductive mechanism.

[0067] According to various power demands, the number of battery cells 20 in the battery 10 may be set to any value. The plurality of battery cells 20 can be connected in series, parallel, or series-parallel connection modes to realize a relatively large capacity or power. Since the number of battery cells 20 included in each battery 10 may be relatively large, the battery cells 20 may be provided in groups for easy installation, and each group of battery cells 20 constitutes a battery module. The number of battery cells 20 included in the battery module is not limited and may be set according to demand.

[0068] FIG. 4 is a schematic structural diagram of a battery cell 20 according to an embodiment of the present application, and FIG. 5 is a partially exploded schematic structural diagram of a battery cell 20 according to an embodiment of the present application. For example, the battery cell 20 shown in FIG. 5 may be any one of the battery cells 20 in FIGS. 2 to 4. As shown in FIGS. 4 and 5, the battery cell 20 of 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 accommodated in the case 21.

[0069] It should be understood that the casing 211 of the embodiment of the present application is a member for accommodating the electrode assembly 22, and the casing 211 may have a hollow structure with an opening formed at one end or a plurality of ends. For example, when the casing 211 has a hollow structure with an opening formed at one end, one cover 212 may be provided, and when the casing 211 has a hollow structure with openings formed at both opposite ends, two covers 212 may be provided, and the two covers 212 are respectively attached to the openings at both ends of the casing 211.

[0070] The casing 211 may have various shapes, such as a cylinder, a cuboid, or other polyhedrons. Exemplarily, as shown in FIGS. 4 and 5, in the embodiment of the present application, mainly the casing 211 has a cuboid structure, and the case where the casing 211 has a hollow structure with an opening formed at one end will be described as an example.

[0071] It should be understood that the cover 212 of the embodiment of the present application is a member that is attached to the opening of the casing 211 to block the internal environment of the battery cell 20 from the external environment. The shape of the cover 212 may be adapted to the shape of the casing 211. As shown in FIGS. 4 and 5, the casing 211 has a cuboid structure, and the cover 212 has a rectangular plate-like structure adapted to the casing 211.

[0072] In the embodiment of the present application, the material of the casing 211 may be various, such as copper, iron, aluminum, steel, aluminum alloy, etc. The material of the cover 212 may also be various, such as copper, iron, aluminum, steel, aluminum alloy, etc. Optionally, 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 of the embodiments of the present application are electrically connected to the electrode assembly 22 inside the battery cell 20 and are used to output the power of the battery cell 20. As shown in FIGS. 4 to 5, the battery cell 20 may include at least two electrode terminals 214, and the at least two electrode terminals 214 may include at least one positive electrode terminal 214a and at least one negative electrode terminal 214b. The positive electrode terminal 214a is used to be electrically connected to the positive tab 222a of the electrode assembly 22, and the negative electrode terminal 214b is used to be electrically connected to the 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. Exemplarily, the positive electrode terminal 214a may be electrically connected to the positive tab 222a by one connecting material, and the negative electrode terminal 214b may be electrically connected to the negative tab 222b by one connecting material.

[0074] In the battery cell 20, the electrode assembly 22 is a member in which an electrochemical reaction occurs in the battery cell 20. According to the actual usage requirements, one or a plurality of electrode assemblies 22 may be provided in the casing 211. For example, as shown in FIGS. 4 and 5, two electrode assemblies 22 are provided in the battery cell 20. The electrode assembly 22 may be a cylinder, a cuboid, etc. When the electrode assembly 22 has a cylinder structure, the casing 211 may have a cylinder structure, and when the electrode assembly 22 has a cuboid structure, the casing 211 may have a cuboid structure.

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

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

[0077] As shown in FIGS. 6 to 9, the electrode assembly 22 of the embodiment of the present application includes a first electrode plate 31 including a plurality of first laminated portions 312 and at least one first bending portion 311. The plurality of first laminated portions 312 are laminated and provided along a first direction X. The first bending 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 bending portion 311. The first direction X is perpendicular to the first laminated portion 312. Here, the first bending portion 311 includes a plurality of first scores 313 arranged along a second direction Y. The second direction Y is the extending direction of the first bending portion 311. The plurality of first scores 313 include a first edge score 3131 located at both ends of the first electrode plate 31 along the second direction Y and a first central score 3132 located in the central region of the first electrode plate 31. 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 of the embodiment of the present application may be any one of the electrode plates of the electrode assembly 22. For example, it may be the positive electrode plate or the negative electrode plate of the electrode assembly 22. For the convenience of description, FIGS. 6 to 8 will describe the case where the first electrode plate 31 is the negative electrode plate as an example, but the embodiment of the present application is not limited thereto.

[0079] As shown in FIGS. 6 to 8, for the electrode assembly 22, the first stacked portion 312 of 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, for the unfolded first electrode plate 31 shown in FIG. 9, the first stacked portion 312 and the first bent portion 311 are connected to each other and provided at intervals, that is, two first bent portions 311 are connected to both ends of each first stacked portion 312, and two first stacked 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 bent portion 311, and a plurality of first stacked portions 312 are stacked and provided along the first direction X, and the electrode assembly 22 is formed. Here, the first direction is a direction perpendicular to the first stacked portion 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 the second direction Y. Here, as shown in FIG. 9, the second direction Y is the extending direction of the first bent portion 311, that is, the second direction Y is perpendicular to the side where the tab 222 of the first electrode plate 31 is located, that is, perpendicular to the end face where 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 embodiment 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 of the embodiment of the present application includes the vertically upward direction and the vertically downward direction shown in FIG. 9. Both 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. 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] Also, when the plurality of first scores 313 includes a plurality of first edge scores 3131, the length L1 of the first edge score 3131 of the embodiment of the present application along the second direction Y may refer to the average value, minimum value, or maximum value of the lengths of the plurality of first edge scores 3131 along the second direction Y. For example, as shown in FIG. 9, taking the case where the plurality of first scores 313 includes two first edge scores 3131 as an example, if 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, the length L1 of the first edge score 3131 of the embodiment of the present application along the second direction Y may be the minimum value of the 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 of the embodiment of the present application may include at least one first central score 3132 located in the central region of the first electrode plate 31. When the plurality of first scores 313 includes a plurality of first central scores 3132, the length L2 of the first central score 3132 of the embodiment of the present application along the second direction Y may refer to the average value, minimum value, or maximum value of the lengths of the plurality of first central scores 3132 along the second direction Y. For example, as shown in FIG. 9, taking the case where the plurality of first scores 313 includes five first central scores 3132 as an example, here, in order from top to bottom, if the lengths of the five first central scores 3132 along the second direction Y are L21, L22, L23, L24, and L25 respectively, the length L2 of the first central score 3132 of the embodiment of the present application along the second direction Y may be the maximum value of the lengths L21 to L25, but the embodiment of the present application is not limited thereto.

[0084] Therefore, in the embodiments of the present application, the first bending portion 311 includes a plurality of first scores 313 arranged along the second direction Y. The positioning of the first bending portion 311 is realized by the plurality of first scores 313, which can reduce the deviation at the bending position of the first electrode plate 31 and the deviation between different electrode plates of the electrode assembly 22. Moreover, the plurality of first scores 313 can also reduce the difficulty of bending, reduce the resistance during bending, and improve the processing efficiency of the electrode assembly 22. Further, when the first bending portion 311 is bent, the resistance at the edge positions of both ends of the first electrode plate 31 along the second direction Y is greater than the resistance at the central position of the first electrode plate 31. And considering that the variation of the fold line at the edge position of the first electrode plate 31 is greater, 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 central score 3132 along the second direction Y, the resistance at the edge position of the first electrode plate 31 can be further reduced, the variation can be decreased, and the probability of deviation when the first electrode plate 31 is bent can be further reduced, reducing the possibility of deposition of the active material or invalidation of the electrode assembly 22, and improving the processing efficiency and the yield rate of the electrode assembly 22.

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

[0086] It should be understood that the bending direction W of the embodiment of the present application may include a clockwise direction W1 and a counterclockwise direction W2, and as shown in FIGS. 6 to 9, the first electrode plate 31 may include a plurality of first bending 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 bending portions 311 with the same bending direction, or the first electrode plate 31 may include first bending portions 311 with different bending directions. The embodiments of the present application are not limited thereto.

[0087] It should be understood that the length L1 along the second direction Y of the first edge score 3131 of the embodiment of the present application may be flexibly set according to actual applications. When the first bending 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 or may not be equal, and the positions of the plurality of first edge scores 313 along the second direction Y may be flexibly installed according to actual applications. Similarly, the length L2 along the second direction Y of the first center score 3132 of the embodiment of the present application may also be flexibly set according to actual applications. When the first bending portion 311 includes a plurality of first center scores 3132, the lengths of the plurality of first center scores 3132 along the second direction Y may or may not be equal, and the positions of the plurality of first center scores 3132 along the second direction Y may also be flexibly installed according to actual applications. Hereinafter, examples will be given and described in combination with several specific embodiments.

[0088] Optionally, as an example, the length L1 along the second direction Y of the first edge score 3131 is more than three times the length L2 along the second direction Y of the first central score 3132, and / or the length L1 along the second direction Y of the first edge score 3131 is not more than five times the length L2 along the second direction Y of the first central score 3132. Specifically, when the length L1 along the second direction Y of the first edge score 3131 is less than three times the length L2 along the second direction Y of the first central score 3132, the dimension of the first edge score 3131 is too small to effectively reduce the resistance of the edge region of the first electrode plate 31 during the bending process, and the processing efficiency of the electrode assembly 22 cannot be effectively improved. When the length L1 along the second direction Y of the first edge score 3131 is more than five times the length L2 along the second direction Y of the first central score 3132, the dimension of the first edge score 3131 is too large, which reduces the structural strength of the first electrode plate 31 and affects the processing yield of the electrode assembly 22.

[0089] Optionally, as an example, when the plurality of first scores 313 includes the plurality of first central scores 3132, the lengths along the second direction Y of the plurality of first central scores 3132 are equal, and / or the intervals along the second direction Y of the plurality of first central scores 3132 are equal. Specifically, as shown in FIGS. 6 to 9, taking the case where the plurality of first scores 313 includes five first central scores 3132 as an example, when the lengths along the second direction Y of the five first central scores 3132 are L21, L22, L23, L24, and L25 in order from top to bottom, the five first central scores 3132 may be set to satisfy that the lengths L21, L22, L23, L24, and L25 are all equal. Also, when the lengths of the intervals along the second direction Y between the five first central scores 3132 are D12, D23, D34, and D45 in order from top to bottom, the five first central scores 3132 may be set to satisfy that the lengths D12, D23, D34, and D45 are all equal.

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

[0091] Optionally, as an example, 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 close to the tab 222 along the second direction Y is smaller than the length L12 of the first edge score 3131 away from the tab 222 along the second direction Y. Specifically, as shown in FIGS. 6 to 9, the length of the first edge score 3131 close to the tab 222 along the second direction Y is L11, while the length of the first edge score 3131 away from the tab 222 along the second direction Y is L12.

[0092] Optionally, as an example, the range of the value of the ratio between the distance D2 between the end of the first current collector 31 along the second direction Y corresponding to the first edge score 3131 and the length D1 of the first current collector 31 along the second direction Y is [0.008, 0.02]. The range of this value is verified by a large number of experiments. Specifically, as shown in FIGS. 6 to 9, when the plurality of first scores 313 include the plurality of first edge scores 3131, the distance D2 between the first edge score 3131 of the embodiment of the present application and the end of the corresponding first current collector 31 along the second direction Y may refer to the average value, the minimum value or the maximum value of the distances between the plurality of first edge scores 3131 and the ends of the corresponding first current collector 31 along the second direction Y. For example, as shown in FIG. 9, taking the case where the plurality of first scores 313 include two first edge scores 3131 as an example, when the distance between the upper first edge score 3131 along the second direction Y and the upper edge of the first current collector 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 current collector 31 is D22, the distance D2 between the first edge score 3131 of the embodiment of the present application and the end of the corresponding first current collector 31 along the second direction Y may be the minimum value of D21 and D22, but the embodiment of the present application is not limited thereto.

[0093] If the ratio between the distance D2 and the length D1 is too small, for example, less than 0.008, the distance D2 between the first edge score 3131 and the edge of the corresponding first current collector 31 along the second direction Y is too small, resulting in insufficient strength in the region between the first edge score 3131 and the edge of the first current collector 31, reducing the structural strength of the first current collector 31, affecting the processing efficiency and performance of the electrode assembly 22, and also increasing the requirements for the processing accuracy of the corresponding first edge score 3131, increasing the difficulty of processing, which is disadvantageous to the processing efficiency of the electrode assembly 22. Therefore, the ratio between the distance D2 and the length D1 should not be too small.

[0094] Conversely, if the ratio between the distance D2 and the length D1 is too large, for example, greater than 0.02, the distance D2 between the first edge score 3131 and the edge of the first polar plate 31 along the second direction Y is relatively too large, which affects the effect of reducing the bending resistance of the edge of the first polar plate 31 by the first edge score 3131, and the difficulty of bending the electrode assembly 22 cannot be effectively reduced, which is disadvantageous to the processing efficiency of the electrode assembly 22. Therefore, the ratio between the distance D2 and the length D1 should not be too large.

[0095] Optionally, the ratio between the distance D2 and the length D1 may be set according to the actual application. For example, the ratio between the distance D2 and the 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] Also, the magnitude of the distance D2 between the end of the first polar plate 31 corresponding to the first edge score 3131 in the second direction Y of the embodiment of the present application may also be set according to the actual application. For example, it may be set such that the value range of the distance D2 is [1 mm, 30 mm]. This value range is verified by a large number of experiments, and the distance D2 is neither too large nor too small. Also 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 magnitude of the length D1 along the second direction Y of the first electrode plate 31 of the embodiment of the present application may be set according to the actual application. For example, it may be set such that the range of the value of the length D1 is [50 mm, 1200 mm], and this range of values is verified by a large number of experiments. Also, for example, the 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] Optionally, as an embodiment, the range of the value of the distance D3 between the first central score 3132 adjacent to the first edge score 3131 is [1 mm, 10 mm]. This range of values is verified by a large number of experiments. Specifically, as shown in FIGS. 6 to 9, when the plurality of first scores 313 include a plurality of first edge scores 3131, the distance D3 between the first central score 3132 adjacent to the first edge score 3131 of the embodiment of the present application may refer to the maximum value, the minimum value, or the average value of the distances between each first edge score 3131 among the plurality of first edge scores 3131 and the corresponding first central score 3132. For example, as shown in FIG. 9, taking the case where the plurality of first scores 313 include two first edge scores 3131 as an example, when the distance between one first central score 3132 adjacent to the upper first edge score 3131 along the second direction Y is D31 and the distance between one first central score 3132 adjacent to the lower first edge score 3131 along the second direction Y is D32, the distance D3 between the first central score 3132 adjacent to the first edge score 3131 of the embodiment of the present application may be the minimum value of D31 and D32, but the embodiment of the present application is not limited thereto.

[0099] When the distance D3 is too large, that is, when the distance between the first edge score 3131 and the first central score 3132 provided is relatively large, the resistance applied during the process of bending the region between the first edge score 3131 and the adjacent first central score 3132 is still relatively large, and the resistance during the bending process of the electrode assembly 22 cannot be reduced well and effectively, which is disadvantageous for improving the processing efficiency of the electrode assembly 22. Therefore, the distance D3 should not be too large. Conversely, when the distance D3 is too small, that is, when the distance between the first edge score 3131 and the first central score 3132 provided is relatively small, the structural strength of the region between the first edge score 3131 and the first central score 3132 provided is too low, which affects the structural strength of the first electrode plate 31 and the structural strength of the electrode assembly 22. And the requirement for the processing accuracy of the first central score 3132 adjacent to the first edge score 3131 is relatively high, which increases the difficulty of processing the electrode assembly 22 and affects the processing efficiency of the electrode assembly 22. Therefore, the distance D3 should not be too small.

[0100] Optionally, the specific value of the distance D3 may be set according to the actual application. For example, specifically, the distance D3 may be 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 embodiment of the present application, the structure of the first score 313 may be flexibly arranged according to the actual application. For example, as shown in FIGS. 6 to 9, the first score 313 is a through hole, which is easy to process, and can extremely significantly reduce the resistance during the bending process and improve the processing efficiency of the electrode assembly 22.

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

[0103] Optionally, when the first score 313 is a concave groove, the concave groove may be realized in various ways. For example, the concave groove may be realized by thinning a part of the first electrode plate 31. In this case, the thickness of the bottom wall of the concave groove is smaller than the thickness of the region of the first electrode plate 31 other than the concave groove. Also, for example, the opening direction of the concave groove may be flexibly set according to the actual application. For example, the opening of the concave groove may face the center direction of the electrode assembly 22, or the opening may face away from the center of the electrode assembly 22. The embodiments of the present application are not limited thereto.

[0104] Optionally, the types of the first edge score 3131 and the first central score 3132 included in the first score 313 of the embodiment 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 may be a concave groove, or both the first edge score 3131 and the first central score 3132 may be through holes. The embodiments of the present application are not limited thereto.

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

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

[0107] Optionally, the plurality of first bending portions 311 include two first bending portions 311 with opposite bending directions W, and the dimensions along the bending direction W of the first score 313 provided on the two first bending portions 311 are equal. Specifically, as shown in FIG. 6, here, taking any one of the plurality of first bending portions 311 bent along the clockwise direction W1 among the plurality of first bending portions 311 as an example, the dimension along the clockwise direction W1 of the first bending portion 311 is R1. Also, taking any one of the plurality of first bending portions 311 bent along the counterclockwise direction W2 among the plurality of first bending portions 311 as an example, the dimension along the counterclockwise direction W2 of the first bending portion 311 is R2. In this case, by setting the dimension R1 to be equal to R2, the forces applied to the plurality of first bending portions 311 bent along different bending directions W are made more uniform, the formed electrode assembly 22 is more uniform, the displacement between different first stacking portions 312 is reduced, and the processing efficiency and the qualified product rate of the electrode assembly 22 are improved.

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

[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 to 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 so as 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 in this way, 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, which is easy to process, improves the structural strength of the electrode assembly 22, and can also reduce the problem that the local strength of the electrode assembly 22 is too low.

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

[0112] Optionally, along the third direction Z, the first bending portion 311 corresponds to at least one second electrode plate 32, and along the 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 the first score 313 provided on any one of the first bending portions 311 in FIG. 6 as an example, 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 bending portion 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. Or, when a plurality of second electrode plates 32 are provided corresponding to the first bending portion 311 along the third direction Z, the dimension L3 is less than or equal to the total dimension of the plurality of second electrode plates 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, it is possible to reduce the deposition phenomenon of the active material caused by the dimension of the first score 313 being too large, and it is also possible to reduce the influence on the performance of the electrode assembly 22.

[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 second electrode plate 32 having a polarity opposite to that of the first electrode plate 31, and the first electrode plate 31 and the second electrode plate 32 are provided by winding around a winding axis. Specifically, as shown in FIG. 8, the first electrode plate 31 and the second electrode plate 32 may be wound to form the electrode assembly 22. In this way, the process of repeatedly cutting the second electrode plate 32 before winding can be reduced, and the winding process can be accelerated.

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

[0116] Furthermore, the second bending portion 321 includes a plurality of second scores 323 arranged along the second direction Y. The plurality of second scores 323 include 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. The length of the second edge score 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 on the second bending portion 321 of the second electrode plate 32 in the embodiments of the present application are the same as the plurality of first scores 313 provided on the first bending portion 311 of the first electrode plate 31, and are applicable to the description of the first score 313. For the sake of brevity, no further description is given here.

[0117] In the embodiment 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 also 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 embodiment of the present application, the dimension along the bending direction W of the score provided on the bending portion close 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 along 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, in the direction radially outward along the radial direction from the center of the electrode assembly 22, the first electrode plate 31 and the second electrode plate 32 together include three first bending portions 311 and two second bending portions 321, and the dimension along the bending direction W of the score provided on the five bending portions also gradually increases in the radial direction from the inside to the outside of the electrode assembly 22.

[0120] Along the radial direction from the inside to the outside of the electrode assembly 22, the arc lengths of the first bending portions 311 of the first electrode plate 31 and the second bending portions 321 of the second electrode plate 32 gradually increase, that is, the bending radius gradually increases. Accordingly, by setting the dimensions along the bending direction W of the first score 313 and the second score 323 to also gradually increase in the radial direction from the inside to the outside of the electrode assembly 22, the dimensions of the scores provided on the bending portions with relatively small arc lengths can also be relatively small, and the dimensions of the scores provided on the bending portions with relatively large arc lengths can also be relatively large, which is easy to process, improves the structural strength of the electrode assembly 22, and can also reduce the problem that the local strength of the electrode assembly 22 is 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 the present application may be the same or opposite. For example, in the above embodiments of the present application, mainly taking the case where the first electrode plate 31 is the negative electrode plate as an example, the problem of deposition of the active material can be reduced, and the influence on the performance of the electrode assembly 22 can also be reduced. Also, for example, in the above embodiments of the present application, mainly taking the case where the second electrode plate 32 is the positive electrode plate as an example, the problem of deposition of the active material can be reduced, and the influence on the performance of the electrode assembly 22 can also be reduced.

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

[0123] Optionally, the negative electrode plate includes a negative electrode current collector 314 whose surface is not coated with a negative electrode active material. In this way, the overall thickness of the negative electrode plate is reduced, the weight of the formed electrode assembly 22 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 is increased. For example, the thickness of the positive electrode active material layer 325 of the positive electrode plate is increased, and the energy density of the battery cell 20 including the electrode assembly 22 can be increased.

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

[0125] As shown in FIGS. 10 - 11, the positive electrode plate of an 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, respectively. Here, the material of the positive electrode active material layer 325 of the embodiment of the present application may be flexibly set according to actual applications. For example, the material of the positive electrode active material layer 325 includes at least one of Prussian blue - type sodium ion positive electrode materials, layered oxide sodium ion positive electrode materials, and polyanion sodium materials. The electrode assembly 22 and the battery cell 20 formed by adopting such a positive electrode active material layer 325 have better high - temperature resistance performance, and reduce the possibility of explosion of the battery cell 20 at high temperatures.

[0126] Optionally, the electrode assembly 22 of the embodiment of the present application may further include a separation membrane 33, and the separation membrane 33 may be located between the first electrode plate 31 and the second electrode plate 32. For example, the separation membrane 33 may be located between the positive electrode plate and the negative electrode plate so as to separate the positive electrode plate and the negative electrode plate. The material of the separation membrane 33 of the embodiment of the present application may be installed according to actual applications. For example, the material of the separation membrane 33 may be an alumina ceramic coating layer and a polyvinylidene difluoride (PVDF) adhesive, and the embodiment of the present application is not limited thereto.

[0127] Therefore, the electrode assembly 22 of the embodiment of the present application includes a first electrode plate 31 including a plurality of first laminated portions 312 and at least one bending portion 311. The plurality of first laminated portions 312 are laminated and provided along a first direction X, and the first direction X is perpendicular to the first laminated portions 312. The first bending portion 311 is used to connect two first laminated portions 312, and the first electrode plate 31 can be bent at the first bending portion 311. The first bending portion 311 includes a plurality of first scores 313 arranged along a second direction Y, and the second direction Y is the extending direction of the first bending portion 311. The positioning of the first bending portion 311 can be realized by the plurality of first scores 313, and the deviation at the bending position of the first electrode plate 31 can be reduced. In addition, the plurality of first scores 313 can also reduce the difficulty of bending, reduce the resistance when being bent, and improve the processing efficiency of the electrode assembly 22.

[0128] Further, 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, and further include first central scores 3132 located in the central region of the first electrode plate 31. And 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 central position of the first electrode plate 31. And considering that the variation of the creases at the edge positions of the first electrode plate 31 is larger, by setting the length of the first edge score 3131 along the second direction Y to be greater than the length of the first central score 3132 along the second direction Y, the resistance at the edge position of the first electrode plate 31 can be further reduced, the variation can be decreased, the probability of deviation when the first electrode plate 31 is bent can be further reduced, the possibility of deposition of the active material can be decreased, and the processing efficiency and the yield rate of the electrode assembly 22 can be improved.

[0129] Although the present application has been described with reference to preferred embodiments, various improvements may be made without departing from the scope of the present application, and the members here may be replaced by equivalents. In particular, as long as there is no structural conflict, each technical feature mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the specification, but is intended to include all technical solutions included in the scope of the claims.

Claims

1. A first electrode plate (31) including a plurality of first laminated portions (312) and at least one first bending portion (311), wherein the plurality of first laminated portions (312) are laminated and provided along a first direction, the first bending 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 bending portion (311), and the first direction is perpendicular to the first laminated portion (312). Here, the first bending portion (311) includes a plurality of first scores (313) arranged along a second direction, the second direction is the extending direction of the first bending portion (311), the plurality of first scores (313) include a first edge score (3131) located at both ends of the first electrode plate (31) along the second direction and a first central score (3132) located in a central region of the first electrode plate (31), and the length of the first edge score (3131) along the second direction is greater than the length of the first central score (3132) along the second direction. An electrode assembly.

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

3. The length of the first edge score (3131) along the second direction is 3 times or more the length of the first central score (3132) along the second direction, and / or The electrode assembly according to claim 1 or 2, wherein the length of the first edge score (3131) along the second direction is 5 times or less the length of the first central score (3132) along the second direction.

4. The electrode assembly according to any one of claims 1 to 3, wherein the plurality of first scores (313) include a plurality of the first central scores (3132) having equal lengths along the second direction and / or equal intervals along the second direction.

5. An end portion 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 smaller than the length of the first edge score (3131) away from the tab (222) along the second direction. The electrode assembly according to any one of claims 1 to 4.

6. The range of the value of the ratio between the distance between the first edge score (3131) and the end portion of the first electrode plate (31) corresponding thereto along the second direction, and the length of the first electrode plate (31) along the second direction is [0.008, 0.02]. The electrode assembly according to any one of claims 1 to 5.

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

8. The first score (313) is a through hole, or The first score (313) is a concave groove. The electrode assembly according to any one of claims 1 to 7.

9. The first electrode plate (31) includes a plurality of the first bending portions (311) having different bending directions. The electrode assembly according to any one of claims 1 to 8.

10. The plurality of the first bending portions (311) include two first bending portions (311) having opposite bending directions, and the dimensions of the first score (313) provided in the two first bending portions (311) along the bending direction are equal. The electrode assembly according to claim 9.

11. The first electrode plate (31) includes a plurality of the first bending portions (311), and the bending directions of the plurality of the first bending portions (311) are the same, The dimension of the first score (313) provided in the first bending portion (311) close to the center of the electrode assembly among the plurality of the first bending portions (311) along the bending direction is smaller than the dimension of the first score (313) provided in the first bending portion (311) away from the center of the electrode assembly along the bending direction. The electrode assembly according to any one of claims 1 to 8.

12. The electrode assembly is Further includes a plurality of second electrode plates (32) having opposite polarities to the first electrode plate (31), and the plurality of second electrode plates (32) and the plurality of the first laminated portions (312) are alternately laminated and provided along the first direction. The electrode assembly according to any one of claims 9 to 11.

13. Along the third direction, the first bending portion (311) corresponds to at least one second electrode plate (32), 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 direction and the second direction. The electrode assembly according to claim 12.

14. The electrode assembly is further including a second electrode plate (32) having a polarity opposite to that of the first electrode plate (31), and the first electrode plate (31) and the second electrode plate (32) are provided by being wound around a winding axis. The electrode assembly according to any one of claims 1 to 8 and 11.

15. The second electrode plate (32) includes a plurality of second laminated portions (322) and at least one second bending portion (321), and the second bending portion (321) is used for connecting two adjacent second laminated portions (322). The second bending portion (321) includes a plurality of second scores (323) arranged along the second direction, and the plurality of second scores (323) include second edge scores located at both ends of the second electrode plate (32) along the second direction and a second central score located in a central region of the second electrode plate (32). The length of the second edge score along the second direction is greater than the length of the second central score along the second direction. The electrode assembly according to claim 14.

16. The dimension along the bending direction of the score provided on the bending portion closer to the center of the electrode assembly among the at least one first bending portion (311) and the at least one second bending portion (321) is smaller than the dimension along the bending direction of the score provided on the bending portion farther from the center of the electrode assembly. The electrode assembly according to claim 15.

17. The second electrode plate (32) is a positive electrode plate. The electrode assembly according to any one of claims 12 to 16.

18. 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-based sodium ion positive electrode material, a layered oxide sodium ion positive electrode material, and a polyanion sodium material. The electrode assembly according to claim 17.

19. The first electrode plate (31) is a negative electrode plate. The electrode assembly according to any one of claims 1 to 18.

20. The negative electrode plate includes a negative electrode current collector (314) having no negative electrode active material coated on its surface, and the electrode assembly according to claim 19.

21. A battery cell including the electrode assembly according to any one of claims 1 to 20.

22. A battery including a plurality of battery cells including the electrode assembly according to any one of claims 1 to 20.

23. An electric power consuming device, An electric power consuming device including the electrode assembly according to any one of claims 1 to 20 and a battery for providing electric power to the electric power consuming device.

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