Battery monomer, battery device and electric equipment

Abstract

The invention provides a battery monomer, a battery device and electric equipment, the battery monomer comprises a cathode pole piece, the cathode pole piece comprises a cathode current collector and a cathode active material layer, and the cathode active material layer has a first edge in the width direction of the cathode current collector; the anode pole piece and the cathode pole piece are arranged in a stacked mode, the anode pole piece comprises an anode current collector and an anode active material layer, the anode active material layer is provided with a second edge on the same side as the first edge in the width direction, and the projection of the anode active material layer covers the projection of the cathode active material layer; wherein the cathode active material layer is provided with an overlapping allowance adjusting part, and the overlapping allowance adjusting part comprises a plurality of first concave parts and first convex parts which are distributed along the length direction of the cathode current collector; in the width direction, the first concave parts are arranged in a concave mode from the first edges to the sides, away from the second edges, of the first edges, and a first convex part is arranged between every two adjacent first concave parts. The lithium separation risk can be reduced, and the reliability of the single battery is ensured.

Description

Technical Field

[0001] This application relates to the field of batteries, and in particular to battery cells, battery devices and electrical equipment. Background Technology

[0002] Energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. For electric vehicles, battery technology is a crucial factor in their development.

[0003] However, the battery devices in related technologies are subject to the risk of lithium plating, which affects the reliability of individual battery cells. Summary of the Invention

[0004] In view of the above problems, this application provides a battery cell, a battery device, and an electrical device that can reduce the risk of lithium plating and ensure the reliability of the battery cell.

[0005] In a first aspect, this application provides a battery cell, including a cathode electrode, the cathode electrode including a cathode current collector and a cathode active material layer disposed on the cathode current collector, the cathode active material layer having a first edge in the width direction of the cathode current collector; an anode electrode, stacked with the cathode electrode, the anode electrode including an anode current collector and an anode active material layer disposed on the anode current collector, the anode active material layer having a second edge on the same side as the first edge in the width direction, and in the stacking direction of the anode electrode and the cathode electrode, the projection of the anode active material layer covers the projection of the cathode active material layer; wherein, the cathode active material layer is provided with an overlap allowance adjustment portion, the overlap allowance adjustment portion including a plurality of first recesses and first protrusions distributed along the length direction of the cathode current collector; along the width direction, the first recesses are recessed inward from the first edge to the side opposite to the second edge, and a first protrusion is provided between two adjacent first recesses.

[0006] By setting an overlap allowance adjustment section at the first edge of the cathode active material layer, and utilizing the alternating distribution of the first concave and first convex portions along the length direction to form a non-straight edge structure such as a wavy / serrated edge, structural stability is ensured. This structure allows for controllable OH design values ​​in the width direction of the cathode and anode electrodes. The setting of the first concave portion can achieve a small-scale increase in OH in this area, allowing lithium ions deposited in the cathode active material layer to be more fully received by the anode active material layer, effectively reducing the risk of lithium plating. Furthermore, the non-straight first edge, compared to the straight edge in related technologies, can effectively increase the contact area between the edge region of the cathode electrode and the electrolyte, improve the electrolyte wetting uniformity, accelerate the migration efficiency of ions in the OH region, and allow lithium ions deposited in the cathode active material layer to be more fully received by the anode active material layer, thereby specifically solving the lithium plating problem caused by insufficient lithium ion reception when the OH size is small. This improves the reliability of the battery cell.

[0007] In some embodiments, the first concave portion and the first convex portion are successively distributed along the length direction, and the overlap margin adjustment portion is at least partially distributed along a broken line and / or curve. The structural form of the overlap margin adjustment portion makes the control of OH around the design value uniform and controllable, and allows the effect of local small-scale increase of OH to be more comprehensive. It does not occupy extra space, ensures space utilization and energy density, and further improves the electrolyte wetting uniformity and ion migration efficiency, enhances the lithium ion reception effect, and reduces the risk of lithium plating.

[0008] In some embodiments, the first concave portion and the first convex portion are alternately arranged along the length direction. This alternation ensures the integrity and stability of the first edge wave structure, guaranteeing sufficient electrolyte wetting and unobstructed ion migration channels. The regular alternating distribution helps to make the ion deposition and migration efficiency in different regions of the cathode electrode edge more consistent, reducing the risk of lithium plating caused by ion overload in local OH regions. Simultaneously, the alternating structure facilitates control of electrode coating, die-cutting, and other processing techniques, improving production consistency and yield.

[0009] In some embodiments, along the width direction, there is a difference in the maximum vertical distance between at least two first recesses and the second edge; and / or, along the length direction, there is a difference in the width dimension of at least two first recesses. By making the first recesses have dimensional differences in the width direction and / or length, it adapts to the process requirements in actual production, reducing processing difficulty and production costs. At the same time, the non-uniform size of the first recesses can form diverse ion migration channels at the edge of the cathode electrode, meeting the electrolyte wetting requirements, improving the adaptability of ion reception in different regions, effectively dispersing the ion carrying pressure in the OH region, reducing the risk of lithium plating, and balancing production feasibility and battery reliability.

[0010] In some embodiments, along the width direction, there is a difference between the minimum vertical distances from at least two first protrusions to the second edge; and / or, at least two first protrusions have a difference in width dimension along the length direction.

[0011] By allowing the first protrusion to have dimensional differences in its width and / or length, it is also beneficial to adapt to the characteristics of actual production processes, reduce the requirements for processing precision, and improve production yield. The non-uniform size of the first protrusion allows the first edge and the anode active material layer to form a staggered distribution, increasing the local contact area and electrolyte retention space, which is conducive to the diversity of ion migration paths, avoids excessive ion concentration in local areas, effectively disperses the ion carrying capacity of the OH region, and further reduces the risk of lithium plating; at the same time, it is not necessary to strictly control the uniformity of the protrusion, so as to balance production efficiency and cost control while ensuring battery reliability.

[0012] In some embodiments, the structures of each first recess and each first protrusion are identical, and along the width direction, the recess size of the first recess is equal to the protrusion size of the first protrusion. By ensuring that the recess and protrusion sizes are equal, a regular alternating structure is formed at the cathode edge, facilitating mass production using the same processing technology and improving the consistency and stability of the electrode structure. The regular and symmetrical structure helps maintain a balanced electrolyte wetting and ion migration efficiency across the cathode edge region. The regular structure also facilitates control over the amount of active material used, reducing redundancy and waste while ensuring energy density.

[0013] In some embodiments, the first concave portion is an arc-shaped groove, and the first convex portion is an arc-shaped toothed portion. Along the length direction, the first edge extends at least partially along a uniform wave trajectory. By designing the first concave portion and the first convex portion as arc-shaped grooves and arc-shaped teeth respectively, forming an edge with a uniform wave trajectory, edge stress concentration points can be completely eliminated, reducing the probability of edge cracking and powder shedding during electrode processing or cycling, and improving the stability of the electrode structure. The smooth wave edge can further increase the contact area with the electrolyte, while guiding the electrolyte to form a smooth flow channel, accelerating ion migration and diffusion, which is beneficial to improving the ion receiving efficiency of the OH region and reducing the risk of lithium plating. At the same time, the smooth structure helps to reduce the local accumulation of active materials, balancing energy density and cycle reliability.

[0014] In some embodiments, the first concave portion is a serrated groove, and the first convex portion is a serrated section. Along the length direction, the first edge extends at least partially with a uniform serrated trajectory. Designing the first concave portion and the first convex portion as a serrated groove and a serrated section respectively, forming an edge with a uniform serrated trajectory, can also ensure an increase in the contact area between the cathode edge and the electrolyte within the same length range, improve ion migration efficiency, optimize the ion receiving capacity of the OH region, and effectively reduce the risk of lithium plating. Furthermore, the regular serrated structure processing technology facilitates mass production, balancing production efficiency and cost.

[0015] In some embodiments, the cathode current collector includes a first main body region and a first tab region distributed along the width direction. A cathode active material layer is disposed in the first main body region. An overlap allowance adjustment portion is located on the side of the cathode active material layer facing the first tab region in the width direction. A first concave portion and a first convex portion are provided on one side of the cathode active material layer in the width direction corresponding to both the first main body region and the first tab region. A continuous non-straight-edge structure can be formed on the cathode active material layer, which can further increase the electrolyte contact area in this region and improve the wetting uniformity. It can also realize synchronous local fine-tuning of OH in the first main body region and the first tab region. By increasing the local OH in a small area, the ion collection efficiency is optimized, and the risk of lithium plating in the tab region is specifically reduced.

[0016] In some embodiments, the cathode electrode further includes an insulating layer disposed on the side of the overlap allowance adjustment portion facing the first tab region, and the insulating layer partially covers the first body region and the first tab region. By providing an insulating layer between the overlap allowance adjustment portion and the first tab region, the insulating layer's cross-regional coverage prevents metal debris generated during die-cutting of the anode electrode from piercing the separator and contacting the cathode electrode, thus avoiding short circuits. Simultaneously, it does not affect the fine-tuning function of the wavy edge for OH, ensuring that the effect of optimizing the risk of lithium plating by slightly increasing local OH is not affected. This improves reliability.

[0017] In some embodiments, the anode current collector includes a second body region and a second tab region distributed along its width. The anode active material layer includes a first portion and a second portion, the first portion being disposed in the second body region and the second portion being disposed in the second tab region, with a second edge located on the side of the first portion facing the second tab region. The anode current collector is divided into a second body region and a second tab region along its width. The second body region is used to carry the anode active material and is the main region for ion reception. The second tab region can be used to form tabs and conduct current. The anode active material layer is divided into a first portion and a second portion, the first portion being coated on the second body region and the second portion being coated on the second tab region; the second edge is the edge of the first portion of the anode active material layer facing the second tab region.

[0018] In some embodiments, the second portion has a second recess and a second convex portion on its edge away from the first portion in the width direction, and the second recess and the second convex portion are distributed along the length direction. By providing the second recess and the second convex portion distributed along the length direction on the edge of the second portion of the anode active material layer away from the first portion, a wavy edge structure is formed at the edge of the anode film layer at the root of the anode tab. This adapts to the non-straight edge structure of the cathode while specifically optimizing the performance at the root of the tab. On the one hand, compared with the straight edge in related technologies, the wavy edge can increase the contact area between the root of the tab and the electrolyte, improve the electrolyte wetting effect in this area, optimize the ion migration environment, and help reduce the risk of lithium plating at the root of the tab, thus ensuring battery safety. On the other hand, the wavy edge structure can appropriately reduce the coating area at the root of the anode tab, reduce redundant anode active material in this area, effectively improve the utilization rate of the anode active material, and thus improve the energy density of the battery cell.

[0019] In some embodiments, along the width direction, the minimum vertical distance from the first protrusion to the second edge is d1, and the maximum vertical distance from the first concave portion to the second edge is d2, where d2 is greater than d1, and 1mm ≤ d1 ≤ 3mm. This configuration reduces molding difficulty while ensuring sufficient ion-receiving space at the protrusion position, avoiding the risk of lithium plating due to insufficient OH size. The design where d2 is greater than d1 allows for a small local increase in OH size through the first concave portion, adapting to ion-receiving requirements and effectively reducing the risk of lithium plating. Furthermore, d2 can be controlled within the anode coverage area. This size limitation allows for the use of mature processes, reducing molding difficulty, and enables fine-tuning of OH size to balance reliability and energy density, avoiding adhesion problems at the edges due to size deviations, thus enhancing structural stability and process adaptability.

[0020] In some embodiments, the maximum vertical distance from the first protrusion to the first recess along the width direction is d3, where 0.05mm ≤ d3 ≤ 2.95mm. The value of d3 ensures sufficient contact area between the active material layer and the electrolyte, optimizing the distribution of the active material, while preventing excessive removal of the cathode active material due to an excessively large d3, which would affect the battery's energy density. The lower limit of 0.05mm ensures the core function of the wavy edge structure, while the upper limit of 2.95mm ensures that the deepest part of the first recess remains within the coverage area of ​​the anode active material layer, effectively reducing the risk of lithium plating.

[0021] Secondly, this application provides a battery device including the aforementioned battery cell.

[0022] Thirdly, this application provides an electrical device including the aforementioned battery device.

[0023] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0024] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is a schematic diagram of the structure of a vehicle according to an embodiment of this application; Figure 2 This is a schematic diagram of the structure of a battery device according to an embodiment of this application; Figure 3 This is a schematic diagram of the structure of a single battery cell according to an embodiment of this application; Figure 4 This is a partial structural schematic diagram of the cathode electrode of a battery cell according to an embodiment of this application; Figure 5 This is a partial enlarged view of the area corresponding to the overlap margin adjustment section of the cathode electrode according to an embodiment of this application; Figure 6 This is a partial structural schematic diagram of the anode plate of a battery cell according to an embodiment of this application; Figure 7 This is a partial structural schematic diagram of an electrode assembly according to an embodiment of this application; Figure 8 This is a partial enlarged view of the area corresponding to the overlap margin adjustment section of the cathode electrode according to another embodiment of this application; Figure 9 This is a partial enlarged view of the cathode electrode in the corresponding area of ​​the overlap margin adjustment section according to another embodiment of this application; Figure 10 This is a partial enlarged view of the area corresponding to the overlap margin adjustment section of the cathode electrode in another embodiment of this application; Figure 11 This is a partial enlarged view of the area corresponding to the overlap margin adjustment section of the cathode electrode in another embodiment of this application.

[0025] Marker explanation: 1. Vehicle; 100. Battery unit; 200. Battery cell assembly; 300. Controller; 400. Motor; 10. Box; 10a. First box; 10b. Second box; 20. Battery cell; 21. Outer shell; 211. Housing; 212. End cap; 22. Electrode assembly; 22a. Electrode body; 22b. Electrode tab; 221. Cathode electrode; 2211, Cathode current collector; 22111, First main body region; 22112, First tab region; 2212, cathode active material layer; 2212a, first edge; 2213. Overlap margin adjustment section; 2213a, the first concave part; 2213b, the first convex part; 2214. Insulation layer; 222. Anode plate; 2221. Anode current collector; 22211, Second Main Area; 22212, Second pole ear region; 2222, Anode active material layer; 2222a, Second edge; 22221. Part One; 22222, Part Two; 22223. Second concave part; 22224. The second convex part; 23. Electrode terminals; 24. Pressure relief mechanism; X: width direction; Y: length direction; Z: stacking direction. Detailed Implementation

[0026] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0027] It should be noted that, unless otherwise stated, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by those skilled in the art to which the embodiments of this application pertain.

[0028] In the description of the embodiments of this application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0029] Furthermore, technical terms such as "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of the embodiments of this application, "a plurality of" means two or more, unless otherwise explicitly defined.

[0030] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0031] In the description of the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0032] Currently, judging from market trends, the application of power batteries is becoming increasingly widespread. Power batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of power battery applications, market demand is also constantly increasing.

[0033] In the field of lithium-ion battery technology, the energy density and reliability of individual battery cells are core research and development directions. To improve the energy density of individual battery cells, the industry typically optimizes the electrode structure design, compressing the size of inactive areas as much as possible to increase the loading of active materials. Among these, the control of the overlap margin (OH) in the width direction of the cathode and anode electrodes is one of the key factors affecting the balance of reliability.

[0034] In related technologies, to balance energy density, the OH size is usually controlled within a small, reasonable range. However, this design can easily lead to a decrease in the matching between ion migration and reception during charging. This is especially true for electrodes formed using dry coating processes, where the straight-edge design in these technologies cannot achieve control. Lithium ions deposited on the cathode electrode are difficult to be fully received by the anode electrode, leading to lithium plating. Lithium plating reduces the reliability of the battery cell. Therefore, ensuring a reasonable OH size to reduce the risk of lithium plating and improve the reliability of the battery cell has become one of the urgent technical problems to be solved in this field.

[0035] Research has found that improving the ion receiving matching between the cathode and anode electrodes can reduce the risk of lithium plating and ensure the reliability of individual battery cells.

[0036] Based on this, one embodiment of this application provides a battery cell including a cathode electrode and an anode electrode. The cathode electrode includes a cathode current collector and a cathode active material layer disposed on the cathode current collector, the cathode active material layer having a first edge in the width direction of the cathode current collector. The anode electrode and the cathode electrode are stacked, the anode electrode including an anode current collector and an anode active material layer disposed on the anode current collector, the anode active material layer having a second edge on the same side as the first edge in the width direction, and in the stacking direction of the anode electrode and the cathode electrode, the projection of the anode active material layer covers the projection of the cathode active material layer; wherein, the cathode active material layer is provided with an overlap allowance adjustment portion, the overlap allowance adjustment portion including a plurality of first recesses and first protrusions distributed along the length direction of the cathode current collector; along the width direction, the first recesses are recessed from the first edge inward to the side away from the second edge, and a first protrusion is provided between two adjacent first recesses.

[0037] By setting an overlap allowance adjustment section at the first edge of the cathode active material layer, and utilizing the alternating distribution of the first concave and first convex portions along the length direction to form a non-straight edge structure such as a wavy / serrated edge, structural stability is ensured. This structure allows for controllable OH design values ​​in the width direction of the cathode and anode electrodes. The setting of the first concave portion can achieve a small-scale increase in OH in this area, allowing lithium ions deposited in the cathode active material layer to be more fully received by the anode active material layer, effectively reducing the risk of lithium plating. Furthermore, the non-straight first edge, compared to the straight edge in related technologies, can effectively increase the contact area between the edge region of the cathode electrode and the electrolyte, improve the electrolyte wetting uniformity, accelerate the migration efficiency of ions in the OH region, and allow lithium ions deposited in the cathode active material layer to be more fully received by the anode active material layer, thereby specifically solving the lithium plating problem caused by insufficient lithium ion reception when the OH size is small. This improves the reliability of the battery cell.

[0038] The technical solutions described in this application are applicable to battery devices and electrical equipment. Electrical equipment can be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the above-mentioned electrical equipment.

[0039] For ease of explanation, the following embodiments will be described using vehicle 1 as an example of electrical equipment.

[0040] For example, such as Figure 1 As shown, vehicle 1 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. The interior of vehicle 1 can house a motor 400, a controller 300, and a battery device 100. The controller 300 controls the battery device 100 to supply power to the motor 400. For example, the battery device 100 can be located at the bottom, front, or rear of vehicle 1. The battery device 100 can be used to power vehicle 1; for example, it can serve as the operating power source for the vehicle 1's electrical system, such as meeting the power requirements for starting, navigation, and operation. In another embodiment of this application, the battery device 100 can not only serve as the operating power source for vehicle 1 but also as the driving power source, replacing or partially replacing gasoline or natural gas to provide driving power to vehicle 1.

[0041] It should be understood that the technical solutions described in the embodiments of this application are not limited to the above-mentioned vehicle 1.

[0042] In some embodiments, the battery device 100 may also be used in energy storage devices, such as energy storage cabinets or energy storage containers.

[0043] like Figure 2 As shown, a battery device 100 provided in one embodiment of this application may include one or more battery cell assemblies 200 for providing voltage and capacity in some embodiments.

[0044] The battery cell assembly 200 may include multiple battery cells 20, which are connected in series, parallel, or mixed connection via a busbar. Mixed connection means that some of the multiple battery cells 20 are connected in series and others in parallel.

[0045] The battery cell 20 can be a secondary battery cell, which refers to a battery cell 20 that can be recharged to activate the active materials and continue to be used after the battery cell 20 has been discharged.

[0046] As an example, the battery cell 20 can be a lithium-ion battery cell, a sodium-ion battery cell, a sodium-lithium-ion battery cell, a lithium metal battery cell, a sodium metal battery cell, a lithium-sulfur battery cell, a magnesium-ion battery cell, a nickel-metal hydride battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, etc.

[0047] As an example, the battery cell 20 can be a prismatic battery cell, which includes prismatic battery cells, blade-shaped battery cells, and multi-prismatic battery cells, such as hexagonal prismatic battery cells.

[0048] In some embodiments, the battery cell assembly 200 is typically formed by arranging a plurality of battery cells 20; as an example, the battery cell assembly 200 can be a battery module, which is formed by arranging and fixing a plurality of battery cells 20 into a single module. As an example, a battery module can be formed by bundling a plurality of battery cells 20 together with cable ties.

[0049] In some embodiments, the battery device 100 may be a battery pack, which includes a housing 10 and one or more battery cell assemblies 200, the battery cell assemblies 200 being housed within the housing 10. As an example, the battery cell assembly 200 may be a battery module, and the battery cell assembly 200 may be housed within the housing 10 by securing a battery module to the housing 10. As an example, the battery cell assembly 200 may also be housed within the housing 10 by directly securing multiple battery cells 20 to the housing 10.

[0050] In some embodiments, the housing 10 is used to house the battery cell 20, and the housing 10 can have various structures.

[0051] In some embodiments, the housing 10 may include a first housing 10a and a second housing 10b. The first housing 10a and the second housing 10b are fastened together to form a closed space inside the housing 10 to house the battery cell assembly 200. Here, "closed" refers to covering or closing, and can be sealed or unsealed. The first housing 10a may be a top cover or a bottom plate.

[0052] In some embodiments, the housing 10 may include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, thereby forming an enclosed space inside the housing 10 to accommodate the battery cell assembly 200. As an example, the frame may include multiple side beams.

[0053] In some embodiments, the housing 10 may be part of the chassis structure of the vehicle 1. For example, a portion of the housing 10 may be at least a portion of the floor of the vehicle 1, or a portion of the housing 10 may be at least a portion of the crossbeams and longitudinal beams of the vehicle 1.

[0054] In some embodiments, the battery device 100 may be an energy storage device.

[0055] Energy storage devices can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems. Energy storage devices can store electrical energy as needed and output it when appropriate. For example, energy storage devices can store electrical energy during off-peak hours and provide power to relevant users or electrical equipment during peak hours.

[0056] In some embodiments, the energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0057] The battery device 100 may include multiple battery cells 20, which are connected in series, parallel, or mixed connection via a busbar. Mixed connection means that some of the multiple battery cells 20 are connected in series and some in parallel.

[0058] like Figures 3 to 7 As shown, one embodiment of this application also provides a battery cell 20, including an electrode assembly 22. The electrode assembly 22 includes a cathode electrode 221 and an anode electrode 222. The cathode electrode 221 includes a cathode current collector 2211 and a cathode active material layer 2212 disposed on the cathode current collector 2211. The cathode active material layer 2212 has a first edge 2212a in the width direction X of the cathode current collector 2211. The anode electrode 222 and the cathode electrode 221 are stacked. The anode electrode 222 includes an anode current collector 2221 and an anode active material layer 2222 disposed on the anode current collector 2221. The anode active material layer 2222 has a second edge 2222a disposed on the same side as the first edge 2212a in the width direction X. In the stacking direction Z of the anode electrode 222 and the cathode electrode 221, the projection of the anode active material layer 2222 covers the projection of the cathode active material layer 2212. The cathode active material layer 2212 is provided with an overlap margin adjustment section 2213. The overlap margin adjustment section 2213 enables the cathode active material layer 2212 to have a non-linear structure on one side of the width direction X corresponding to the first edge 2212a.

[0059] In some embodiments, the overlap allowance adjustment portion 2213 includes a plurality of first recesses 2213a and first protrusions 2213b distributed along the length direction Y of the cathode current collector 2211. Along the width direction X, the first recesses 2213a are recessed inward from the side opposite to the second edge 2222a from the first edge 2212a, and a first protrusion 2213b is provided between two adjacent first recesses 2213a.

[0060] In some embodiments, the electrode assembly 22 may be a component in the battery cell 20 where an electrochemical reaction occurs. The number of electrode assemblies 22 may be one or more.

[0061] In some embodiments, the electrode assembly 22 includes a cathode electrode 221 and an anode electrode 222. During the charging and discharging process of the battery cell 20, active ions (e.g., lithium ions) are inserted and extracted back and forth between the cathode electrode 221 and the anode electrode 222.

[0062] In some embodiments, the cathode electrode 221 may include a cathode current collector 2211 and a cathode active material layer 2212 disposed on at least one surface of the cathode current collector 2211.

[0063] As an example, the cathode current collector 2211 has two surfaces opposite each other in its own thickness direction, and the cathode active material layer 2212 is disposed on either or both of the two opposite surfaces of the cathode current collector 2211.

[0064] As an example, the cathode current collector 2211 may be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals may be used, including but not limited to stainless steel, copper, aluminum, nickel, nickel alloys, titanium, or silver. The composite current collector may include a polymer material substrate and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0065] As an example, the cathode active material layer 2212 includes a cathode active material, which may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as battery cathode active materials may also be used. These cathode active materials may be used alone or in combination of two or more. Examples of lithium phosphate include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium manganese iron phosphate, and lithium manganese iron phosphate and carbon composites. Examples of lithium transition metal oxides include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.8 Co 0.15 Al 0.05 At least one of O2 and its modified compounds. Modified compounds refer to substances obtained by modification methods such as doping or coating based on the above-mentioned substances.

[0066] In some embodiments, the anode electrode 222 includes an anode current collector 2221 and an anode active material layer 2222 disposed on at least one surface of the anode current collector 2221.

[0067] As an example, the anode current collector 2221 can be made of metal foil, conductive polymer material, carbon material, or composite current collector. For example, as a metal foil, pure metal, alloy, or surface-treated metal can be used, including but not limited to stainless steel, copper, aluminum, nickel, nickel alloy, titanium, or silver. The composite current collector may include a polymer material substrate and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0068] As an example, the anode electrode 222 may include an anode current collector 2221 and an anode active material layer 2222 disposed on at least one surface of the anode current collector 2221.

[0069] As an example, the anode current collector 2221 has two surfaces opposite each other in its own thickness direction, and the anode active material layer 2222 is disposed on either or both of the two opposite surfaces of the anode current collector 2221.

[0070] As an example, the anode active material layer 2222 includes an anode active material, which may be an anode active material known in the art for use in battery cells 20. As an example, the anode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as anode active materials for battery cells 20 may also be used. These anode active materials may be used alone or in combination of two or more.

[0071] In some embodiments, the anode may be a foamed metal. The foamed metal may be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. When foamed metal is used as the anode electrode, the surface of the foamed metal may or may not contain an anode active material.

[0072] As an example, anolyte active material may be filled or deposited within the anolyte current collector 2221.

[0073] In some embodiments, the cathode current collector 2211 may be made of aluminum, and the anode current collector 2221 may be made of copper.

[0074] In some embodiments, the electrode assembly 22 may further include a spacer disposed between the cathode and the anode.

[0075] In some embodiments, the separator is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0076] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer can be the same or different. The separator can be a single component located between the cathode electrode 221 and the anode electrode 222, or it can be attached to the surface of the cathode electrode 221 and the anode electrode 222. An inorganic particle coating, an organic particle coating, or an organic / inorganic composite coating can also be applied to the surface of the separator.

[0077] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the cathode electrode 221 and the anode electrode 222.

[0078] In some embodiments, the electrode assembly 22 can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0079] In some embodiments, the electrode assembly 22 is a wound structure. The cathode electrode 221 and the anode electrode are wound into a wound structure.

[0080] In some embodiments, the electrode assembly 22 is a stacked structure.

[0081] As an example, multiple cathode electrodes 221 and multiple anode electrodes 222 can be provided respectively, and multiple cathode electrodes 221 and multiple anode electrodes 222 can be stacked alternately.

[0082] As an example, multiple cathode electrodes 221 can be provided, and multiple stacked folded segments can be formed by folding anode electrodes 222, with a cathode electrode 221 sandwiched between adjacent folded segments.

[0083] As an example, both the cathode electrode 221 and the anode electrode 222 are folded to form multiple stacked folded segments.

[0084] As an example, multiple isolation elements can be provided, which are respectively provided between any adjacent cathode electrode 221 or anode electrode 222.

[0085] As an example, the spacers can be continuously arranged, and can be arranged between any adjacent cathode plates 221 or anode plates 222 by folding or rolling.

[0086] In some embodiments, the electrode assembly 22 may be cylindrical, flat, or polygonal, etc.

[0087] The width direction X and length direction Y of the cathode current collector 2211 can be understood as the width direction and length direction of the electrode. The electrode can be the cathode electrode 221 or the anode electrode 222.

[0088] For the wound electrode assembly 22, the width direction of the electrode sheet can be understood as the direction parallel to the winding axis of the electrode assembly 22, and the length direction of the electrode sheet can be understood as the winding direction of the electrode sheet or the extension length direction in the unwound state. For the stacked electrode assembly 22, both the width direction and the length direction of the electrode sheet are perpendicular to the thickness direction of the electrode sheet.

[0089] For example, the cathode electrode 221 and the anode electrode 222 may each include an electrode body 22a and an electrode tab 22b. It can be understood that the electrode tab 22b is disposed at one end of the width direction of the electrode, and the width direction of the electrode can be determined according to the placement of the electrode tab 22b.

[0090] For example, the width direction X of the cathode current collector 2211 can be the arrangement direction of the electrode body 22a and the tab 22b. The length direction Y of the cathode current collector 2211 can be a direction perpendicular to the width direction X. The cathode current collector 2211 may also have a thickness direction, which can be understood as the thickness direction of the film layer, and the length direction Y, the width direction X, and the thickness direction are perpendicular to each other.

[0091] The stacking direction Z of the anode electrode 222 and the cathode electrode 221 can be perpendicular to the width direction X and the length direction Y of the cathode current collector 2211. The stacking direction Z can also be understood as the thickness direction of the cathode current collector 2211 or the thickness direction of the electrode.

[0092] In the stacking direction Z, the projected area of ​​the anode active material layer 2222 can be larger than the projected area of ​​the cathode active material layer 2212, so that the orthogonal projection of the anode active material layer 2222 covers the orthogonal projection of the cathode active material layer 2212.

[0093] The first edge 2212a and the second edge 2222a are located on the same side of the cathode current collector 2211 in the width direction X. Along the width direction X, the second edge 2222a and the first edge 2212a can be spaced apart to allow the anode active material layer 2222 to adopt an OH (overhang) design. Specifically, after the anode electrode 222 and the cathode electrode 221 are stacked together with the separator, the anode active material layer 2222 on the anode electrode 222 completely covers the cathode active material layer 2212 on the cathode electrode 221. 2. In the width direction X, it protrudes relative to the cathode active material layer 2212 on the cathode electrode 221, so that the area of ​​the anode active material layer 2222 on the anode electrode 222 is larger than the area of ​​the cathode active material layer 2212 on the cathode electrode 221. This ensures that the anode active material layer 2222 on the anode current collector 2221 completely covers the cathode active layer on the cathode current collector 2211, thereby ensuring that the ions deposited from the cathode electrode 221 can be embedded into the anode electrode 222 after passing through the isolation membrane, and ensuring that the ions deposited from the cathode electrode 221 will not scatter outside the anode plate.

[0094] The first edge can be the boundary of the cathode current collector 2211 in the width direction X, which is the starting position of the first recess 2213a. Optionally, the protruding vertex of the first protrusion 2213b can be located at the first edge 2212a. Of course, in some embodiments, the protruding vertex of the first protrusion 2213b in the width direction X may also extend beyond the first edge 2212a.

[0095] like Figure 5 , Figures 8 to 11 As shown, optionally, the shape of the first recess 2213a includes, but is not limited to, an arc-shaped recess, a polygonal recess, or other irregularly shaped recesses.

[0096] Optionally, the shape of the first protrusion 2213b includes, but is not limited to, an arc-shaped protrusion, a polygonal protrusion, or other irregularly shaped protrusions.

[0097] Optionally, the number of first recesses 2213a included in the overlap allowance adjustment portion 2213 provided on the cathode active material layer 2212 can be two, three, or more. The structural forms of each first recess 2213a can be the same, or they can differ. For example, among the multiple first recesses 2213a, at least two first recesses 2213a can have different recess shapes, such as some being triangular, some being arc-shaped, or other polygonal or irregular shapes. The recess depths of at least two first recesses 2213a can also be different, for example, there can be a difference in recess depth along the width direction X.

[0098] Optionally, the number of first protrusions 2213b included in the overlap allowance adjustment section 2213 can be two, three, or more. The structural forms of each first protrusion 2213b can be the same, or they can differ. For example, at least two of the multiple first protrusions 2213b can have different protruding shapes, such as some being triangular, some being semi-circular, or other polygonal or irregular shapes. The protruding heights of at least two first protrusions 2213b can also be different, for example, there can be a difference in the height of the protrusions in the width direction X.

[0099] Optionally, the number of the first recess 2213a and the number of the first convex portion 2213b can be equal, or the number of the two can be different.

[0100] Optionally, the first concave portion 2213a and the first convex portion 2213b can have the same shape, such as both being arc-shaped or polygonal. Of course, they can also be different, such as one being arc-shaped and the other being polygonal.

[0101] Optionally, the first recess 2213a and the first protrusion 2213b can be alternately provided. Of course, one or more first protrusions 2213b can also be provided between two adjacent first recesses 2213a.

[0102] The first recess 2213a is recessed inward from the first edge 2212a on the side away from the second edge 2222a, and a first protrusion 2213b is provided between two adjacent first recesses 2213a.

[0103] The top of the first protrusion 2213b facing the second edge 2222a can be located at the first edge 2212a, or it can protrude from the first edge 2212a.

[0104] The overlap margin adjustment unit 2213 is generally formed by at least one of the following: uniform wave structure, uniform sawtooth structure, non-uniform wave structure, non-uniform sawtooth structure, and wave plus sawtooth structure.

[0105] The second edge 2222a can be the boundary of the anodic active material layer 2222 in the width direction X. The second edge 2222a can be a straight edge. Of course, depending on the constraints of the molding process and other conditions, it can have a certain tilt angle or an approximately straight edge with fluctuations.

[0106] One embodiment of the battery cell 20 provided in this application includes an overlap allowance adjustment portion 2213 at the first edge 2212a of the cathode active material layer 2212. The alternating distribution of the first concave portion 2213a and the first convex portion 2213b along the length direction Y forms a non-straight edge structure such as a wavy / serrated edge, which helps ensure structural stability. This structure allows for controllable OH design values ​​in the width direction for the cathode electrode 221 and the anode electrode 222. The first concave portion 2213a enables a small increase in local OH in this area, allowing lithium ions deposited in the cathode active material layer 2212 to be more fully received by the anode active material layer 2222, effectively reducing the risk of lithium plating. Furthermore, the non-linear first edge 2212a, compared to the straight edge in related technologies, effectively increases the contact area between the edge region of the cathode electrode 221 and the electrolyte, improves the uniformity of electrolyte wetting, accelerates the migration efficiency of ions in the OH region, and allows the lithium ions deposited in the cathode active material layer 2212 to be more fully received by the anode active material layer 2222. This specifically solves the lithium deposition problem caused by insufficient lithium ion reception when the OH size is small, thereby improving the reliability of the battery cell 20.

[0107] like Figures 3 to 7 As shown, in some embodiments, the battery cell 20 further includes a housing 21, in which at least a portion of the electrode assembly 22 is housed.

[0108] In some embodiments, the outer casing 21 may be a steel casing, an aluminum casing, a plastic casing (such as a polypropylene casing), or a composite metal casing, etc.

[0109] In some embodiments, the housing 21 can be a sealed structure or a non-sealed structure. As an example, when the housing 21 is a non-sealed structure, it serves to protect the electrode assembly 22, and a sealing bag is included between the housing 21 and the electrode assembly 22. The sealing bag is used to encapsulate the electrode assembly 22 and the electrolyte. Specifically, the sealing bag can be a bag-shaped insulating component or an aluminum-plastic film. When the housing 21 is a sealed structure, it is used to encapsulate the electrode assembly 22 and the electrolyte, among other components.

[0110] In some embodiments, the casing 21 of the battery cell 20 may be a square casing, a prismatic casing, or a casing of other shapes.

[0111] In some embodiments, the housing 21 includes a housing 211 and an end cap 212, the housing 211 having an opening, and the end cap 212 being connected to the housing 211 and covering the opening.

[0112] The housing 211 is a component used to fit the end cap 212 to form an internal cavity of the battery cell 20, which can be used to accommodate the electrode assembly 22, electrolyte and other components.

[0113] The housing 211 and the end cap 212 can be separate components. For example, an opening can be provided on the housing 211, and the end cap 212 can be used to close the opening to form an internal cavity for the battery cell 20.

[0114] The housing 211 can be of various shapes and sizes, such as cuboid or cylindrical. Specifically, the shape of the housing 211 can be determined according to the specific shape and size of the electrode assembly 22. The housing 211 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0115] The shape of the end cap 212 can be adapted to the shape of the housing 211 to fit the housing 211. The material of the end cap can be the same as or different from the material of the housing 211. Optionally, the end cap can be made of a material with a certain hardness and strength (such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.), so that the end cap is not easily deformed when subjected to compression and impact, so that the battery cell 20 can have higher structural strength and improve reliability.

[0116] The end cap 212 is connected to the housing 211 by welding, bonding, snap-fitting or other means.

[0117] The housing 211 may be open at one end or open at both ends. In some examples, the housing 211 may be a structure with an opening on one side, with one end cap covering the housing 211. In other examples, the housing 211 may be a structure with openings on both sides, with two end caps covering the two openings of the housing 211 respectively.

[0118] In some embodiments, the electrode assembly 22 includes an electrode body 22a and two tabs 22b of opposite polarity, which extend from the electrode body. One of the two tabs 22b is a positive tab, and the other is a negative tab.

[0119] In some embodiments, the battery cell 20 further includes two electrode terminals 23 disposed on the housing 21, and each electrode terminal 23 is electrically connected to a tab 22b of the same polarity.

[0120] The electrode terminal 23 can be disposed on the end cap or on the housing 211.

[0121] In some embodiments, a pressure relief mechanism 24 may also be provided on the housing 21. The pressure relief mechanism 24 is used to release the internal gas of the battery cell 20.

[0122] In some embodiments, the battery cell 20 further includes an electrolyte contained within a housing 21. The electrolyte acts as a conductor of ions between the cathode and anode. The electrolyte can be liquid, gel-like, or solid.

[0123] In some embodiments, the liquid electrolyte includes an electrolyte salt and a solvent.

[0124] In some embodiments, the electrolyte salt may be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0125] In some embodiments, the solvent may be selected from at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0126] In some embodiments, the electrolyte may optionally include additives. For example, additives may include anodic film-forming additives, cathode film-forming additives, and additives that can improve certain properties of the battery cell 20, such as additives that improve the overcharge / fast charge performance of the battery cell 20, additives that improve the high-temperature performance of the battery cell 20, additives that improve the low-temperature performance of the battery cell 20, etc.

[0127] In some embodiments, the gel electrolyte comprises a polymer as a backbone network and can be used in conjunction with an ionic liquid-lithium salt.

[0128] In some embodiments, the solid electrolyte includes a polymer solid electrolyte, an inorganic solid electrolyte, and a composite solid electrolyte.

[0129] As an example, the polymers of polymeric solid electrolytes may include polyethers (polyoxyethylene), polysiloxanes, polycarbonates, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids, cellulose, etc.

[0130] As an example, inorganic solid electrolytes can be one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphorus sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0131] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0132] like Figure 5 , Figures 8 to 11 As shown, in some embodiments, the battery cell 20 provided in one embodiment of this application has a first recess 2213a and a first convex portion 2213b successively distributed along the length direction Y, and the overlap margin adjustment portion 2213 is at least partially distributed along a broken line and / or a curve.

[0133] Optionally, along the length direction Y of the cathode current collector 2211, the first concave portion 2213a and the first convex portion 2213b can be distributed in a continuous and successive manner, and the overlap margin adjustment portion 2213 can be distributed along a broken line trajectory or along a curved trajectory. Of course, it can also be distributed partly along a broken line trajectory and partly along a curved trajectory.

[0134] The broken line can be a regular or irregular broken line, such as an acute-angled broken line or an obtuse-angled broken line, and the curve can be a regular or irregular curve, such as a circular arc curve or a parabolic curve.

[0135] The battery cell 20 provided in one embodiment of this application has an overlap margin adjustment section 2213 structure that makes the control of OH around the design value uniform and controllable. This allows for a more comprehensive coverage of the effect of a small increase in local OH, without occupying extra space, ensuring space utilization and energy density, and further improving electrolyte wetting uniformity and ion migration efficiency, enhancing lithium ion reception, and reducing the risk of lithium plating.

[0136] like Figure 5 As shown, in some embodiments, along the length direction Y, the first recess 2213a and the first protrusion 2213b are alternately arranged.

[0137] The alternation method can be uniform spacing or non-uniform spacing depending on the ion requirements of different regions of the electrode.

[0138] The first protrusion 2213b and the first recess 2213a can be provided successively, with a first protrusion 2213b formed between two adjacent first recesses 2213a. Of course, in some embodiments, the first protrusion 2213b and the first recess 2213a can be provided at intervals in the length direction Y.

[0139] One embodiment of the battery cell 20 provided in this application ensures the integrity and stability of the wave structure of the first edge 2212a by alternating the first concave portion 2213a and the first convex portion 2213b, thus guaranteeing sufficient electrolyte wetting and unobstructed ion migration channels. The regular alternating distribution helps to make the ion deposition and migration efficiency of each region of the cathode electrode 221 more consistent, reducing the risk of lithium plating caused by ion overload in local OH regions. At the same time, the alternating structure facilitates the control of electrode coating, die-cutting and other processing technologies, improving production consistency and yield.

[0140] The first edge 2212a can be a regular polyline and / or curved structure. Of course, the first edge 2212a can also be an irregular polyline and / or curved structure.

[0141] like Figure 10 As shown, in some embodiments, along the width direction X, there is a difference between the maximum vertical distances from at least two first recesses 2213a to the second edge 2222a.

[0142] This allows for the vertical distances from a portion of the first recesses 2213a to the second edge 2222a to be equal, while a difference exists between the vertical distances from a portion of the first recesses 2213a to the second edge 2222a.

[0143] Of course, it is also possible to make a difference between the vertical distances from any two first recesses 2213a to the second edge 2222a.

[0144] The maximum vertical distance from the first recess 2213a to the second edge 2222a can be understood as the maximum vertical distance between the lowest point of the first recess 2213a in the width direction X and the second edge 2222a.

[0145] In some alternative embodiments, at least two first recesses 2213a have a difference in width dimension h1 along the length direction Y of the cathode current collector 2211.

[0146] The width h1 of the first recess 2213a can be understood as the maximum distance between the two ends of the first recess 2213a in the length direction Y.

[0147] This allows a number of the first recesses 2213a to have the same width along the length direction Y, while a number of the first recesses 2213a have a difference in width along the length direction Y.

[0148] Of course, it is also possible to make the width of any two first recesses 2213a differ along the length direction Y.

[0149] One embodiment of the battery cell 20 provided in this application allows for dimensional differences in the width direction X and / or length of the first recess 2213a, adapting to actual production process requirements and reducing processing difficulty and production costs. Simultaneously, the non-uniform size of the first recess 2213a enables the formation of diverse ion migration channels at the edge of the cathode electrode 221, meeting electrolyte wetting requirements, improving the adaptability of ion reception in different regions, effectively dispersing the ion-carrying pressure in the OH region, reducing the risk of lithium plating, and balancing production feasibility and battery reliability.

[0150] like Figure 10 As shown, in some embodiments, along the width direction X, there is a difference between the minimum vertical distances from at least two first protrusions 2213b to the second edge 2222a.

[0151] The minimum vertical distance from the first protrusion 2213b to the second edge 2222a can be understood as: the vertical distance between the highest point of the first protrusion 2213b and the second edge 2222a in the width direction X.

[0152] This allows a number of the first protrusions 2213b to have equal vertical distances to the second edge 2222a, and a difference exists between the minimum vertical distances of a number of the first protrusions 2213b to the second edge 2222a.

[0153] Of course, it is also possible to make a difference between the minimum vertical distances between any two first protrusions 2213b and the second edge 2222a.

[0154] At least two of the first protrusions 2213b have a difference in width h2 in the length direction Y.

[0155] The width h2 of the first protrusion 2213b can be understood as the maximum distance between the two ends of the first protrusion 2213b in the length direction Y.

[0156] It is possible to make a portion of the first protrusions 2213b have equal width dimensions along the length direction Y, and a portion of the first protrusions 2213b have different width dimensions along the length direction Y.

[0157] Of course, it is also possible to make the width dimensions of any two first protrusions 2213b differ along the length direction Y.

[0158] One embodiment of the battery cell 20 provided in this application allows for dimensional differences in the width and / or length direction Y of the first protrusion 2213b, which facilitates adaptation to actual production process characteristics, reduces processing precision requirements, and improves production yield. The non-uniform size of the first protrusion 2213b allows the first edge 2212a and the anode active material layer 2222 to form a staggered distribution, increasing the local contact area and electrolyte retention space, which is beneficial to the diversity of ion migration paths, avoids excessive ion concentration in local areas, effectively disperses the ion carrying capacity of the OH region, and further reduces the risk of lithium plating; at the same time, it is not necessary to strictly control the uniformity of the first protrusion 2213b, so as to balance production efficiency and cost control while ensuring battery reliability.

[0159] like Figure 5 , Figure 8 , Figure 9 , Figure 11 As shown, in some embodiments, each of the first recesses 2213a has the same structure, and each of the first protrusions 2213b has the same structure. Along the width direction X, the recess size of the first recess 2213a is equal to the protrusion size of the first protrusion 2213b.

[0160] Optionally, at least one of the structural parameters of each first recess 2213a, such as the recess depth dimension in the width direction X, the width dimension in the length direction Y, the shape, and the spacing, is the same.

[0161] Optionally, the structural parameters of each first protrusion 2213b, such as at least one of the height dimension in the width direction X, the width dimension in the length direction Y, the shape, and the spacing, are the same.

[0162] Optionally, along the width direction X of the cathode current collector 2211, the recess size (i.e., recess depth) of the first recess 2213a is equal to the protrusion size (i.e. protrusion height) of the first protrusion 2213b.

[0163] Optionally, the first concave portion 2213a and the first convex portion 2213b may be regular shapes such as rectangles, trapezoids, and arcs to form a symmetrical or regular alternating structure.

[0164] One embodiment of this application provides a battery cell 20 with equal concave and convex dimensions, forming a regular alternating structure at the cathode edge. This facilitates mass production using the same processing technology, improving the consistency and stability of the electrode structure. The regular and symmetrical structure helps maintain a balanced electrolyte wetting and ion migration efficiency across the cathode edge regions. The regular structure also helps control the amount of active material used, reducing redundancy and waste while ensuring energy density.

[0165] like Figure 9As shown, in some embodiments, the first recess 2213a is an arc-shaped groove, the first protrusion 2213b is an arc-shaped tooth, and the first edge 2212a extends at least partially along a uniform wave trajectory along the length direction Y.

[0166] The arc-shaped groove can be made of smooth curves such as circular arc or elliptical arc. The first protrusion 2213b corresponds to an arc-shaped tooth, and the curve of the arc-shaped tooth can match the curve of the arc-shaped groove to form a smooth transition edge structure.

[0167] One embodiment of the battery cell 20 provided in this application designs the first concave portion 2213a and the first convex portion 2213b as an arc-shaped groove and an arc-shaped tooth, respectively, forming an edge with a uniform wave trajectory. This completely eliminates edge stress concentration points, reduces the probability of edge cracking and powder shedding during electrode processing or cycling, and improves the stability of the electrode structure. The smooth wave edge can further increase the contact area with the electrolyte, while guiding the electrolyte to form a smooth flow channel, accelerating ion migration and diffusion, which is beneficial to improving the ion reception efficiency of the OH region and reducing the risk of lithium plating. At the same time, the smooth structure helps to reduce the local accumulation of active materials, balancing energy density and cycle reliability.

[0168] like Figure 5 , Figure 8 , Figure 10 , Figure 11 As shown, in some embodiments, the first recess 2213a is a serrated groove, the first protrusion 2213b is a serrated portion, and the first edge 2212a extends at least partially along the length direction Y with a uniform serrated trajectory.

[0169] The serrated groove can be a triangular groove, a trapezoidal groove, or other structures. When a triangular groove is used, it includes, but is not limited to, isosceles triangles, right triangles, and other serrated shapes. When a trapezoidal groove is used, it includes, but is not limited to, isosceles trapezoids and other structures.

[0170] The edges of the serrated part can be adapted to the edges of the serrated groove. Along the length direction Y of the cathode current collector 2211, at least a portion of the first edge 2212a extends with a uniform serrated trajectory. The tooth height and tooth pitch of the serrated trajectory can be kept consistent to form a regular serrated edge.

[0171] In one embodiment of this application, the battery cell 20 has a first recess 2213a and a first protrusion 2213b designed as a serrated groove and a serrated portion, respectively, forming an edge with a uniform serrated trajectory. This design also ensures that the contact area between the cathode edge and the electrolyte is increased within the same length range, improving ion migration efficiency, optimizing the ion receiving capacity of the OH region, and effectively reducing the risk of lithium plating. Furthermore, the regular serrated structure processing technology facilitates mass production, balancing production efficiency and cost.

[0172] Continue reading Figures 4 to 7 As shown, in some embodiments, the cathode current collector 2211 includes a first main body region 22111 and a first tab region 22112 distributed along the width direction X. The cathode active material layer 2212 is disposed in the first main body region 22111. The overlap margin adjustment part 2213 is located on the side of the cathode active material layer 2212 facing the first tab region 22112 in the width direction X. The cathode active material layer 2212 is provided with a first recess 2213a and a first protrusion 2213b on the side of the cathode active material layer 2212 corresponding to the first main body region 22111 and the first tab region 22112 in the width direction X.

[0173] The cathode current collector 2211 includes a first main body region 22111 and a first tab region 22112 along the width direction X. The first main body region 22111 is the main area for carrying the core active material and realizing the ion reaction. The first tab region 22112 is the area for forming tabs 22b and conducting current. The cathode active material layer 2212 is coated on the first main body region 22111, and the overlap allowance adjustment part 2213 is provided on the edge of the cathode active material layer 2212 facing the first tab region 22112. Along the length direction Y of the cathode current collector 2211, the cathode active material layer 2212 is provided with a first recess 2213a and a first protrusion 2213b in the area corresponding to the first main body region 22111 and the first tab region 22112, which can form a non-linear structure such as a continuous wavy edge or a sawtooth edge structure in the length direction Y.

[0174] The battery cell 20 provided in one embodiment of this application, through the above-described configuration, can form a continuous non-straight-edge structure on the cathode active material layer 2212, which can further increase the electrolyte contact area and improve the wetting uniformity in this region, and can also achieve synchronous local fine-tuning of the first main body region 22111 and the first tab region 22112OH. By increasing the local OH in a small range, the ion receiving efficiency is optimized, and the risk of lithium plating in the tab 22b region is specifically reduced.

[0175] Continue reading Figures 4 to 7 As shown, in some embodiments, the cathode electrode 221 further includes an insulating layer 2214, which is disposed on the side of the overlap margin adjustment portion 2213 facing the first tab region 22112, and partially covers the first main body region 22111 and the first tab region 22112.

[0176] The insulating layer 2214 can be made of insulating materials such as PP and PE, and can be set by coating or bonding. The insulating layer 2214 is located on the side of the overlap margin adjustment part 2213 facing the first electrode area 22112, and partially covers the first main body area 22111 and partially covers the first electrode area 22112, forming a cross-regional insulating protection structure.

[0177] The insulating layer 2214 and the cathode active material layer 2212 can be distributed along the width direction X.

[0178] The first edge 2212a of the cathode active material layer 2212 is disposed toward the insulating layer 2214 in the width direction X. The shape of the side of the insulating layer 2214 toward the first edge 2212a of the cathode active material layer 2212 in the width direction X can match the shape of the overlap allowance adjustment part 2213. The two can be disposed one after the other, or a gap can be formed in the width direction X.

[0179] One embodiment of the battery cell 20 provided in this application provides an insulating layer 2214 between the overlap margin adjustment section 2213 and the first tab region 22112. The insulating layer 2214 covers the entire area, preventing metal debris generated during die-cutting of the anode electrode 222 from piercing the separator and contacting the cathode electrode 221, thus avoiding a short circuit. Simultaneously, it does not affect the fine-tuning function of the wavy edge for OH, ensuring that the effect of optimizing the lithium plating risk by slightly increasing the local OH area is not affected. This improves reliability.

[0180] Continue reading Figures 4 to 7 As shown, in some embodiments, the anode current collector 2221 includes a second main body region 22211 and a second tab region 22212 distributed along the width direction X. The anode active material layer 2222 includes a first part 22221 and a second part 22222. The first part 22221 is disposed in the second main body region 22211, and the second part 22222 is disposed in the second tab region 22212. The second edge 2222a is located on the side of the first part 22221 facing the second tab region 22212.

[0181] The anode current collector 2221 is divided into a second main body region 22211 and a second tab region 22212 along the width direction X. The second main body region 22211 is used to carry the anode active material and is the main area for ion reception. The second tab region 22212 can be used to form the tab 22b and conduct current. The anode active material layer 2222 is divided into a first part 22221 and a second part 22222. The first part 22221 is coated on the second main body region 22211, and the second part 22222 is coated on the second tab region 22212. The second edge 2222a is the edge of the first part 22221 of the anode active material layer 2222 facing the second tab region 22212.

[0182] The second edge 2222a can optionally be a straight line structure.

[0183] In one embodiment of this application, the battery cell 20 is configured as described above to determine the position of the second edge 2222a, ensuring that the projection of the cathode active material layer 2212 falls completely within the projection range of the first part 22221 of the anode active material layer 2222, thus structurally guaranteeing the effectiveness of ion reception.

[0184] Continue reading Figures 4 to 7 As shown, in some embodiments, along the width direction X, the minimum vertical distance from the first protrusion 2213b to the second edge 2222a is d1, and the maximum vertical distance from the first concave portion 2213a to the second edge 2222a is d2, where d2 is greater than d1 and 1mm≤d1≤3mm.

[0185] The value of d1 can be any value between 1 mm and 3 mm, and can include any value between 1.5 mm and 2.5 mm. In some optional embodiments, d1 can include 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, and 2.5 mm.

[0186] The value of d2 is greater than the value of d1. For example, the difference between the two can be any value between 0.05mm and 2.95mm.

[0187] The battery cell 20 provided in one embodiment of this application, through the above-described configuration, can reduce the molding difficulty and ensure that the protruding position has sufficient ion receiving space, avoiding the risk of lithium plating caused by insufficient OH size. The design of d2 being greater than d1, through the first concave portion 2213a, achieves a localized small-scale increase in OH size, adapting to ion receiving requirements and effectively reducing the risk of lithium plating. Moreover, d2 can be controlled within the anode coverage area. At the same time, the size limitation can both utilize mature processes, reduce molding difficulty, and balance reliability and energy density through OH differentiation fine-tuning, avoiding bonding force problems at the edges caused by size deviations, and enhancing structural stability and process adaptability.

[0188] Continue reading Figures 4 to 7 As shown, in some embodiments, the second portion 22222 has a second recess 22223 and a second protrusion 22224 on the side edge opposite to the first portion 22221 in the width direction X, and the second recess 22223 and the second protrusion 22224 are distributed along the length direction Y.

[0189] Along the width direction X, the second part 22222 of the anode active material layer 2222 has a second recess 22223 and a second convex part 22224 on one side edge away from the first part 22221; the second recess 22223 and the second convex part 22224 are distributed along the length direction Y and can be in the form of arc, sawtooth or other shapes.

[0190] One embodiment of the battery cell 20 provided in this application features a wavy edge structure at the edge of the second portion 22222 of the anode active material layer 2222, which is opposite to the first portion 22221. This structure is formed by providing a second recess 22223 and a second protrusion 22224 distributed along the length direction Y at the edge of the anode film layer at the root of the anode tab 22b. This structure adapts to the non-straight edge structure of the cathode while specifically optimizing the performance at the root of the tab 22b. On the one hand, the wavy edge increases the contact area between the root of the tab 22b and the electrolyte compared to the straight edge in related technologies, improving the electrolyte wetting effect in this area, optimizing the ion migration environment, and helping to reduce the risk of lithium plating at the root of the tab 22b, thus ensuring battery safety. On the other hand, the wavy edge structure can appropriately reduce the coating area at the root of the anode tab 22b, reducing redundant anode active material in this area, effectively improving the utilization rate of the anode active material, and thereby increasing the energy density of the battery cell 20.

[0191] Meanwhile, this structure is compatible with dry coating scraper / trimming processes, without adding extra processing difficulty, reducing waste of active materials and debris generated during cutting, and improving processing yield.

[0192] like Figures 4 to 7 As shown, in some embodiments, the maximum vertical distance from the first protrusion 2213b to the first recess 2213a along the width direction X is d3, where 0.05mm≤d3≤2.95mm.

[0193] The maximum vertical distance d3 between the first protrusion 2213b and the first recess 2213a can be any value between 0.05mm and 2.95mm, including the two end values ​​of 0.05mm and 2.95mm.

[0194] With the above settings, the value of OH can be between 1.05 and 5.95 mm. Compared with a straight edge, the area of ​​OH increases by 1.6% to 98%.

[0195] In some optional embodiments, d3 can be any number between 0.05 mm and 2.9 mm. In some optional embodiments, the value of d3 can be any value between 0.1 mm and 1 mm, for example, the value of d3 can be any value between 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, and 0.9 mm.

[0196] In one embodiment of this application, the battery cell 20 has a value of d3 that ensures the contact area between the active material layer and the electrolyte and optimizes the distribution of the active material, while preventing excessive removal of the cathode active material due to an excessively large d3, which would affect the battery's energy density. The lower limit of 0.05 mm ensures the core function of the wavy edge structure, while the upper limit of 2.95 mm ensures that the deepest part of the first recess 2213a remains within the coverage of the anode active material layer 2222, effectively reducing the risk of lithium plating.

[0197] One embodiment of this application provides a battery cell 20, which includes a housing 21 and an electrode assembly 22. The housing 21 includes a shell 211 and an end cap. The shell 211 and the end cap enclose a receiving cavity. An electrode terminal 23 is provided on the end cap. The electrode assembly 22 is disposed in the receiving cavity and electrically connected to the electrode terminal 23.

[0198] The electrode assembly 22 includes a cathode electrode 221 and an anode electrode 222, which can be fabricated using a dry forming process. The cathode electrode 221 includes a cathode current collector 2211 and a cathode active material layer 2212 disposed on the cathode current collector 2211. The cathode active material layer 2212 has a first edge 2212a in the width direction X of the cathode current collector 2211. The anode electrode 222 is stacked with the cathode electrode 221. The anode electrode 222 includes an anode current collector 2221 and an anode active material layer 2222 disposed on the anode current collector 2221. The anode active material layer 2222 has a second edge 2222a on the same side as and spaced apart from the first edge 2212a in the width direction X. In the stacking direction Z of the anode electrode 222 and the cathode electrode 221, the projection of the anode active material layer 2222 covers the projection of the cathode active material layer 2212. The cathode active material layer 2212 is provided with an overlap margin adjustment section 2213, which includes a plurality of first recesses 2213a and first protrusions 2213b distributed along the length direction Y of the cathode current collector 2211. Along the width direction X, the first recesses 2213a are recessed inward from the side opposite to the second edge 2222a from the first edge 2212a, and a first protrusion 2213b is provided between two adjacent first recesses 2213a. A difference exists between the maximum vertical distances from at least two first recesses 2213a to the second edge 2222a along the width direction X, and a difference exists in the width dimensions of at least two first recesses 2213a along the length direction Y. Similarly, a difference exists between the minimum vertical distances from at least two first protrusions 2213b to the second edge 2222a along the width direction X; and a difference exists in the width dimensions of at least two first protrusions 2213b along the length direction Y. The first recess 2213a is a sawtooth groove, and the first protrusion 2213b is a sawtooth portion. Along the length direction Y, the first edge 2212a extends at least partially with a uniform sawtooth trajectory. The cathode current collector 2211 includes a first main body region 22111 and a first tab region 22112 distributed along the width direction X. The cathode active material layer 2212 is disposed in the first main body region 22111. The overlap margin adjustment part 2213 is located on the side of the cathode active material layer 2212 facing the first tab region 22112 in the width direction X. The cathode active material layer 2212 is provided with a first recess 2213a and a first protrusion 2213b in the width direction X corresponding to both the first main body region 22111 and the first tab region 22112. The cathode electrode 221 also includes an insulating layer 2214, which is disposed on the side of the overlap margin adjustment portion 2213 facing the first tab region 22112. The insulating layer 2214 partially covers the first main body region 22111 and the first tab region 22112.The anode current collector 2221 includes a second main body region 22211 and a second tab region 22212 distributed along the width direction X. The anode active material layer 2222 includes a first part 22221 and a second part 22222. The first part 22221 is disposed in the second main body region 22211, and the second part 22222 is disposed in the second tab region 22212. The second edge 2222a is located on the side of the first part 22221 facing the second tab region 22212. Along the width direction X, the minimum vertical distance from the first protrusion 2213b to the second edge 2222a is d1, and the maximum vertical distance from the first recess 2213a to the second edge 2222a is d2. d2 is greater than d1, where d1 can be selected as 1 mm and d2 as 1.5 mm. Along the width direction X, the maximum vertical distance from the first protrusion 2213b to the first recess 2213a is d3, where d3 can be selected as 2.5 mm. The second part 22222 has a second recess 22223 and a second protrusion 22224 on the side edge opposite to the first part 22221 in the width direction X. The second recess 22223 and the second protrusion 22224 are distributed along the length direction Y.

[0199] Secondly, this application provides a battery device 100, including the aforementioned battery cell 20.

[0200] Thirdly, this application provides an electrical device including the aforementioned battery device 100, which is used to provide electrical energy.

[0201] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: A cathode electrode, the cathode electrode comprising a cathode current collector and a cathode active material layer disposed on the cathode current collector, the cathode active material layer having a first edge in the width direction of the cathode current collector; An anode electrode is stacked with the cathode electrode. The anode electrode includes an anode current collector and an anode active material layer disposed on the anode current collector. The anode active material layer has a second edge on the same side as the first edge in the width direction. In the stacking direction of the anode electrode and the cathode electrode, the projection of the anode active material layer covers the projection of the cathode active layer. The cathode active material layer is provided with an overlap margin adjustment part, which includes a plurality of first recesses and first protrusions distributed along the length direction of the cathode current collector; along the width direction, the first recesses are recessed from the first edge inward to the side away from the second edge, and the first protrusions are provided between two adjacent first recesses.

2. The battery cell according to claim 1, characterized in that, Along the length direction, the first concave portion and the first convex portion are successively distributed, and the overlap allowance adjustment portion is at least partially distributed along a broken line and / or a curve.

3. The battery cell according to claim 1, characterized in that, Along the length direction, the first concave portion and the first convex portion are alternately arranged.

4. The battery cell according to any one of claims 1 to 3, characterized in that, Along the width direction, there is a difference between the maximum vertical distances from at least two of the first recesses to the second edge; And / or, along the length direction, there is a difference in the width dimensions of at least two of the first recesses.

5. The battery cell according to any one of claims 1 to 3, characterized in that, Along the width direction, there is a difference between the minimum vertical distances from at least two of the first protrusions to the second edge; and / or, there is a difference in the width dimension of at least two of the first protrusions in the length direction.

6. The battery cell according to any one of claims 1 to 3, characterized in that, Each of the first recesses has the same structure, and each of the first protrusions has the same structure. Along the width direction, the recess size of the first recess is equal to the protrusion size of the first protrusion.

7. The battery cell according to claim 6, characterized in that, The first concave portion is an arc-shaped groove, the first convex portion is an arc-shaped tooth, and along the length direction, the first edge extends at least partially along a uniform wave trajectory.

8. The battery cell according to claim 6, characterized in that, The first recess is a serrated groove, the first protrusion is a serrated portion, and the first edge extends at least partially along the length direction in a uniform serrated trajectory.

9. The battery cell according to any one of claims 1 to 3, characterized in that, The cathode current collector includes a first main body region and a first tab region distributed along the width direction. The cathode active material layer is disposed in the first main body region. The overlap margin adjustment part is located on the side of the cathode active material layer facing the first tab region in the width direction. The cathode active material layer is provided with the first concave portion and the first convex portion on one side of the width direction corresponding to both the first main body region and the first tab region.

10. The battery cell according to claim 9, characterized in that, The cathode electrode also includes an insulating layer, which is disposed on the side of the overlap margin adjustment portion facing the first electrode tab region, and the insulating layer partially covers the first main body region and the first electrode tab region.

11. The battery cell according to claim 9, characterized in that, The anode current collector includes a second main body region and a second tab region distributed along the width direction. The anode active material layer includes a first part and a second part. The first part is disposed in the second main body region, the second part is disposed in the second tab region, and the second edge is located on the side of the first part facing the second tab region.

12. The battery cell according to claim 11, characterized in that, The second part has a second recess and a second protrusion on one side edge away from the first part in the width direction, and the second recess and the second protrusion are distributed along the length direction.

13. The battery cell according to any one of claims 1 to 3, characterized in that, Along the width direction, the minimum vertical distance from the first protrusion to the second edge is d1, and the maximum vertical distance from the first concave portion to the second edge is d2, where d2 is greater than d1 and 1mm ≤ d1 ≤ 3mm.

14. The battery cell according to any one of claims 1 to 3, characterized in that, Along the width direction, the maximum vertical distance from the first protrusion to the first concave portion is d3, where 0.05mm≤d3≤2.95mm.

15. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1 to 14.

16. An electrical appliance, characterized in that, Includes the battery device as described in claim 15.

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