Battery cell, battery device, power consuming device, and energy storage device

Abstract

The application provides a battery monomer, a battery device, a power utilization device and an energy storage device, and belongs to the technical field of batteries. The battery monomer comprises a cathode sheet and an anode sheet, and the cathode sheet and the anode sheet are laminated and wound to form a winding main body. The anode sheet comprises an anode current collector and anode active material layers located on both sides of the anode current collector, wherein the anode current collector has a bending area and a hollow hole located in the bending area, and the anode active material layers cover the hollow hole. The battery monomer provided by the application can improve the problem that the bending area of the anode sheet is prone to lithium precipitation, and improve the stability of the battery monomer.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell, battery device, power supply device, and energy storage device. Background Technology

[0002] Energy conservation and emission reduction are key to sustainable social development. Rechargeable batteries, with their ability to store and release energy as needed, are widely used in various electrical devices and energy storage systems, and are an important component in promoting energy transition and sustainable development. For the new energy industry, battery technology is a crucial factor in its development.

[0003] A battery cell includes a cathode sheet and an anode sheet. After the anode sheet and cathode sheet are stacked and wound into a winding structure, at the bend of the winding structure, the arc length of the convex surface of the anode sheet is less than the arc length of the concave surface of the adjacent cathode sheet. This results in insufficient lithium intercalation capability of the convex surface of the anode sheet for lithium ions that have escaped from the concave surface of the adjacent cathode sheet, which in turn makes it easy for lithium plating to occur on the anode sheet, affecting the reliability of the battery cell. Utility Model Content

[0004] This application aims to at least solve one of the technical problems existing in the background art. To this end, one object of this application is to provide a battery cell, battery device, power consumption device, and energy storage device to improve the problem of lithium plating easily occurring in the bending area of ​​the anode sheet.

[0005] An embodiment of the first aspect of this application provides a battery cell including a cathode sheet and an anode sheet, which are stacked and wound to form a wound body. The anode sheet includes an anode current collector and an anode active material layer located on both sides of the anode current collector, wherein the anode current collector has a bending region and a perforation located in the bending region, and the anode active material layer covers the perforation.

[0006] In the technical solution of this application embodiment, both the anode sheet and the cathode sheet in the winding body have bending areas. The bending areas of the cathode sheet and the anode sheet both include convex and concave surfaces. When the concave surface of the cathode sheet and the convex surface of the anode sheet are adjacent in the winding body, a hollow hole is provided in the bending area of ​​the anode current collector. Lithium ions that escape from the concave surface of the cathode sheet can be embedded in the convex surface of the adjacent anode sheet. Some lithium ions can be transported through the hollow hole and embedded in the concave surface of the anode sheet, so that all lithium ions that escape from the concave surface of the cathode sheet can be embedded inside the anode sheet, thereby improving the problem of lithium plating that easily occurs in the anode sheet and improving the stability of the battery cell.

[0007] In some embodiments, the anode current collector is wound into multiple turns in a direction from the winding center axis near the winding body to the winding center axis away from the winding body, with the perforated holes located at least within the bending region of the anode current collector closest to the winding center axis. Because the difference in arc length between the convex surface of the anode sheet and the concave surface of the adjacent cathode sheet is the largest in the innermost ring of the bending region—that is, the difference between the anode capacity and the cathode capacity is the largest—the innermost ring of the anode sheet is more prone to lithium plating compared to other rings. By setting the perforated holes at least within the bending region of the innermost ring of the anode current collector, the likelihood of lithium plating on the anode sheet can be reduced, and the placement of the perforated holes in other rings of the anode current collector can be adjusted according to actual needs.

[0008] In some embodiments, the bending regions of the anode current collector have perforated holes. This reduces the likelihood of lithium plating on the convex surface of the anode sheet in each turn, thereby improving the lithium plating problem of the battery cell and enhancing its reliability.

[0009] In some embodiments, the battery cell further includes a conductive element, which is located at least within the perforated hole. Because of the conductive element within the perforated hole, when the active material is coated onto the surface of the anode current collector, the active material is less likely to flow into the perforated hole and clog it. It also reduces the probability of the active material flowing out from the other end of the perforated hole, thereby reducing the possibility of active material contaminating the production equipment. Furthermore, the conductive element facilitates the timely transport of lithium ions from the convex surface of the anode to the concave surface, improving lithium ion conduction efficiency and thus reducing the risk of lithium plating on the anode.

[0010] In some embodiments, the anode current collector has multiple perforated holes arranged in an array. Conductive elements are also located on both sides of the anode current collector. Along at least one of the row and column directions of the arrayed perforated holes, the conductive elements within any two adjacent perforated holes are connected to the conductive elements located on both sides of the anode current collector. Providing multiple perforated holes and multiple conductive elements within them can improve the transfer efficiency of lithium ions from the convex surface of the anode sheet to the concave surface. Furthermore, the conductive elements being located on both sides of the anode current collector increases the contact area between the conductive elements and the anode active material layer, facilitating the timely transfer of lithium ions from the anode active material layer to the concave surface of the anode sheet through the conductive elements, thereby reducing the risk of lithium plating on the anode sheet.

[0011] In some embodiments, along the row direction, the conductive elements in any two adjacent perforated holes are connected by conductive elements located on both sides of the anode current collector. The conductive elements located on both sides of the anode current collector extend along the row direction, the column direction is the same as the width direction of the anode current collector, and the row direction is perpendicular to the column direction. Setting the conductive elements to extend along the row direction simplifies the manufacturing process of the conductive elements. In addition, it can improve the tensile strength of the electrode and enhance the reliability of the electrode.

[0012] In some embodiments, along the column direction, the difference between the width of the conductive element on both sides of the anode current collector and the diameter of the perforated hole is greater than or equal to 0 and less than or equal to 0.5 mm. This prevents the conductive element from covering too much of the anode current collector surface, thereby increasing the contact area between the anode current collector and the anode active material layer and improving the current transmission performance of the battery cell.

[0013] In some embodiments, along the row direction, the maximum spacing between two perforated holes is greater than or equal to 10 mm and less than or equal to 50 mm. This spacing along the row direction ensures that the area ratio of multiple perforated holes on the anode current collector is not too large, thus not reducing the surface area of ​​the anode current collector and affecting the electrical transport performance of the battery cell, nor that the number of perforated holes is too small, thus not reducing the lithium-ion transport efficiency through the perforated holes.

[0014] In some embodiments, along the column direction, the difference between the maximum spacing between two perforated holes and the width of the anode current collector is greater than or equal to 0 and less than or equal to 5 mm. Along the column direction, this results in a larger area ratio of multiple perforated holes on the anode current collector, i.e., a larger number of perforated holes, which can improve the efficiency of lithium ion transport from the convex surface of the anode plate to the concave surface of the anode plate and reduce the risk of lithium plating on the anode plate.

[0015] In some embodiments, the thickness of the conductive elements located on both sides of the anode current collector is greater than or equal to 0.5 μm and less than or equal to 3 μm. This allows the conductive elements to have good ion conduction performance while reducing the space they occupy, increasing the volume of the anode active material layer coated on the surface of the anode current collector, thereby improving the energy density of the battery cell.

[0016] In some embodiments, the conductive element is made of one of polyethylene, polypropylene, polyvinylidene fluoride and hexafluoropropylene copolymer, polyacrylamide, polyacrylonitrile, or polyvinyl alcohol. The conductive element can absorb electrolyte, thereby forming a good ion-conducting pathway within the perforated holes, improving lithium-ion transfer efficiency. Furthermore, the conductive element has good tensile strength, reducing the risk of anode breakage or strip breakage during electrode rolling or other processes.

[0017] In some embodiments, the diameter of the perforated hole is greater than or equal to 1 mm and less than or equal to 5 mm. Maintaining the diameter of the perforated hole within the above range ensures that the diameter is large enough to facilitate the placement of conductive elements within the hole and allow lithium ions to pass smoothly through the perforated hole to embed into the concave surface of the anode plate; at the same time, the diameter of the perforated hole is not so large that it occupies the surface area of ​​the anode current collector and affects the electrical transmission performance of the battery cell.

[0018] In some embodiments, the anode current collector has multiple perforations, with the spacing between any two adjacent perforations being greater than or equal to 1 mm and less than or equal to 5 mm. Maintaining the spacing between any two adjacent perforations within this range allows for the provision of a larger number of perforations within the limited area of ​​the anode sheet bending region, improving lithium-ion transport efficiency and reducing the risk of lithium plating on the anode sheet. Simultaneously, it also ensures that the spacing between any two adjacent perforations is not too small, thus facilitating the provision of perforations on the surface of the anode current collector.

[0019] An embodiment of the second aspect of this application provides a battery device that includes the battery cell described in the above embodiments.

[0020] An embodiment of the third aspect of this application provides an electrical device that includes the battery device described in the above embodiments, the battery device being used to provide electrical energy.

[0021] An embodiment of the fourth aspect of this application provides an energy storage device, which includes the battery device described in the above embodiments, and the battery device is used to store electrical energy.

[0022] 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

[0023] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0024] Figure 1 This is a schematic diagram of the vehicle structure according to some embodiments of this application;

[0025] Figure 2 This is an exploded structural diagram of a battery according to some embodiments of this application;

[0026] Figure 3 This is an exploded structural diagram of a battery cell according to some embodiments of this application;

[0027] Figure 4 This is a schematic diagram of the structure of the bending area of ​​the wound body in some embodiments of this application;

[0028] Figure 5 This is a schematic diagram of the structure of the bending area of ​​the wound body in some other embodiments of this application;

[0029] Figure 6This is a top view of the anode current collector in some embodiments of this application;

[0030] Figure 7 This is a cross-sectional view of the anode sheet in some embodiments of this application.

[0031] Explanation of reference numerals in the attached figures:

[0032] 1000, Vehicle; 100, Battery Unit; 200, Controller; 300, Motor; 10, Housing; 11, First Part; 12, Second Part; 20, Battery Cell; 21, End Cap; 21a, Electrode Terminal; 22, Housing; 23, Electrode Assembly; 23a, Tab; 30, Cathode Plate; 31, Cathode Current Collector; 32, Cathode Active Material Layer; 40, Anode Plate; 41, Anode Current Collector; 41a, Bending Area; 411, Hole; 42, Anode Active Material Layer; 50, Separator; 60, Conductor; Row Direction X; Column Direction Y. Detailed Implementation

[0033] 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.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0035] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0036] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0037] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0038] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0039] 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," and "circumferential" 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.

[0040] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. 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.

[0041] Currently, the application of rechargeable batteries is becoming increasingly widespread, judging from market trends. They are not only used in energy storage systems for hydropower, thermal power, wind power, and solar power plants, but also extensively in various electronic devices, such as electric bicycles, electric motorcycles, and electric vehicles, as well as in equipment and aerospace. With the continuous expansion of rechargeable battery applications, market demand is also constantly increasing.

[0042] A battery cell consists of a cathode and an anode, which are stacked and wound together to form a spiral structure. In the bending region of the spiral structure, the arc length of the convex surface of the anode is less than the arc length of the concave surface of the adjacent cathode. This means the anode capacity is less than the cathode capacity, resulting in insufficient lithium intercalation capability of the anode. During charging, lithium ions released from the concave surface of the cathode cannot be fully intercalated into the convex surface of the anode. Excess lithium ions tend to deposit as elemental lithium on the anode, leading to lithium plating. Lithium plating can cause capacity decay, internal short circuits, and other problems in the battery cell, affecting its reliability.

[0043] Based on the above considerations, a battery cell was designed, comprising a cathode sheet and an anode sheet, which are stacked and wound to form a wound body. The anode sheet includes an anode current collector and a layer of anode active material located on both sides of the anode current collector. The anode current collector has a bending region and perforations located in the bending region, and the anode active material layer covers the perforations.

[0044] Both the anode and cathode plates in the winding body have bending areas. The bending areas of both the cathode and anode plates include convex and concave surfaces. When the concave surface of the cathode plate and the convex surface of the anode plate are adjacent in the winding body, a perforation is provided in the bending area of ​​the anode current collector. Lithium ions that escape from the concave surface of the cathode plate can be embedded in the convex surface of the adjacent anode plate. Some lithium ions can be transported through the perforation and embedded in the concave surface of the anode plate, so that the lithium ions that escape from the concave surface of the cathode plate can be completely embedded in the interior of the anode plate, thereby improving the problem of lithium plating that easily occurs in the anode plate and improving the reliability of the battery cell.

[0045] The battery cells disclosed in this application can be used, but are not limited to, in electrical devices or energy storage devices such as vehicles, ships, or aircraft. A power system comprising the battery cells and battery devices disclosed in this application can be used to construct such electrical devices or energy storage devices.

[0046] This application provides an electrical device that uses a battery as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0047] This application also provides an energy storage device that uses a battery as a power source. The energy storage device can be, but is not limited to, an energy storage container, an energy storage cabinet, an energy storage power station, an energy storage battery pack, or a portable energy storage system.

[0048] For ease of explanation, the following embodiments will be described using a vehicle 1000 as an example of an electrical device according to an embodiment of this application.

[0049] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle provided in some embodiments of this application. The vehicle 1000 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. A battery device 100 is installed inside the vehicle 1000, and the battery device 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during starting, navigation, and driving.

[0050] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0051] Please refer to Figure 2 , Figure 2 This is an exploded structural diagram of a battery device provided in some embodiments of this application. The battery device 100 includes a housing 10 and a battery cell 20, with the battery cell 20 housed within the housing 10. The housing 10 provides a space for the battery cell 20 and can have various structures. In some embodiments, the housing 10 may include a first portion 11 and a second portion 12, which overlap each other, jointly defining a space for accommodating the battery cell 20. The second portion 12 may be a hollow structure with one open end, and the first portion 11 may be a plate-like structure, covering the open side of the second portion 12 so that the first portion 11 and the second portion 12 jointly define the space. Alternatively, the first portion 11 and the second portion 12 may both be hollow structures with one open side, with the open side of the first portion 11 covering the open side of the second portion 12. Of course, the housing 10 formed by the first portion 11 and the second portion 12 can have various shapes, such as a cylinder, a cuboid, etc.

[0052] In the battery device 100, there can be multiple battery cells 20. These multiple battery cells 20 can be connected in series, in parallel, or in a mixed manner. A mixed connection means that multiple battery cells 20 can be connected in both series and parallel.

[0053] Figure 3This is an exploded structural diagram of a battery cell according to some embodiments of this application. Figure 4 This is a schematic diagram of the structure of the bending region of the wound body in some embodiments of this application. (Reference) Figure 3 and Figure 4 This application provides a battery cell 20, which includes a cathode sheet 30 and an anode sheet 40. The cathode sheet 30 and the anode sheet 40 are stacked and wound to form a wound body. The anode sheet 40 includes an anode current collector 41 and an anode active material layer 42 located on both sides of the anode current collector 41. The anode current collector 41 has a bending region 41a and a perforation 411 located in the bending region 41a. The anode active material layer 42 covers the perforation 411.

[0054] refer to Figure 3 The battery cell 20 refers to the smallest unit that makes up the battery device. The battery cell 20 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited to these. The battery cell 20 can be cylindrical, flat, cuboid, or other shapes.

[0055] The battery cell 20 may include an end cap 21, a housing 22, an electrode assembly 23, and other functional components.

[0056] End cap 21 refers to a component that covers the opening of housing 22 to isolate the internal environment of battery cell 20 from the external environment. Not limited to this, the shape of end cap 21 can be adapted to the shape of housing 22 to fit the housing 22. Functional components such as electrode terminals 21a may be provided on end cap 21. Electrode terminals 21a can be used for electrical connection with electrode assembly 23 to output or input electrical energy to battery cell 20. In some embodiments, end cap 21 may also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of battery cell 20 reaches a threshold.

[0057] The housing 22 is an assembly used to fit the end cap 21 to form the internal environment of the battery cell 20, wherein the formed internal environment can be used to accommodate the electrode assembly 23, electrolyte and other components.

[0058] Electrode assembly 23 is the component in the battery cell 20 where electrochemical reactions occur. The housing 22 may contain one or more electrode assemblies 23. Electrode assembly 23 may include a cathode plate 30, an anode plate 40, and a separator 50 located between the cathode plate 30 and the anode plate 40. The portions of the cathode plate 30 and the anode plate 40 containing active material constitute the main body of the electrode assembly 23, while the portions of the cathode plate 30 and the anode plate 40 without active material each constitute a tab 23a. During the charging and discharging process of the battery, the cathode active material and the anode active material react with the electrolyte, and the tab 23a connects to the electrode terminal 21a to form a current loop.

[0059] The separator 50 is used to reduce the possibility of short circuits caused by direct contact between the anode plate 40 and the cathode plate 30, thereby improving the safety and stability of the battery cell 20. This application does not impose any particular limitation on the type of separator 50; a porous separator 50 with good chemical and mechanical stability, well-known to those skilled in the art, can be selected.

[0060] In some embodiments, the cathode plate 30, the anode plate 40, and the diaphragm 50 are stacked in sequence and spirally wound around a central axis, so that the formed wound body has a spiral structure.

[0061] The cathode sheet 30 may include a cathode current collector 31 and cathode active material layers 32 located on both sides of the cathode current collector 31. In some embodiments, the constituent materials of the cathode current collector 31 include, but are not limited to, aluminum foil, stainless steel foil, titanium foil, carbon-based materials, etc., and the constituent materials of the cathode active material layers 32 include, but are not limited to, lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, ternary materials, lithium iron phosphate, etc. The thickness of the cathode active material layers 32 coated on both sides of the cathode current collector 31 may be the same or different.

[0062] In some embodiments, the constituent materials of the anode current collector 41 include, but are not limited to, copper foil, stainless steel foil, titanium foil, carbon-based materials, etc., and the constituent materials of the anode active material layer 42 include, but are not limited to, carbon materials, silicon-based materials, tin-based materials, cuprous oxide, manganese dioxide, lithium metal, etc. The thickness of the anode active material layer 42 coated on both sides of the anode current collector 41 can be the same or different.

[0063] It is understood that the wound body has a bending region. In some embodiments, the wound body may include only the bending region, or it may include a straight region and bending regions located at both ends of the straight region.

[0064] In some embodiments, the perforated hole 411 may be located in part of the bending region 41a of the anode current collector 41, or it may be located in all of the bending region 41a of the anode current collector 41.

[0065] The perforated hole 411 penetrates the opposite two surfaces of the anode current collector 41. In some embodiments, the penetration direction of the perforated hole 411 intersects the direction of winding around the central axis. Exemplarily, the penetration direction of the perforated hole 411 is perpendicular to the direction of winding around the central axis, that is, the penetration direction of the perforated hole 411 is the same as the thickness direction of the anode current collector 41.

[0066] In some embodiments, the cross-sectional dimensions of the perforated hole 411 may be the same or not be exactly the same along the through direction of the perforation.

[0067] In some embodiments, along the through-hole direction of the cutout 411, the cross-sectional shape of the cutout 411 includes, but is not limited to, a circle, a square, a triangle, or any other regular or irregular shape.

[0068] In some embodiments, laser drilling or punching can be used to form perforated holes 411 on the anode current collector 41. Subsequently, anode active material is coated on both sides of the anode current collector 41 to form an anode active material layer 42. After drying, cold pressing, die cutting, and other processes, an anode sheet 40 is obtained. When winding the anode sheet 40, the area of ​​the perforated holes 411 formed on the anode current collector 41 can be controlled to be located in the bending area of ​​the electrode assembly 23, thereby obtaining the battery cell 20.

[0069] In the embodiments of this application, both the anode sheet 40 and the cathode sheet 30 in the winding body have bending areas. The bending areas of the cathode sheet 30 and the anode sheet 40 include convex and concave surfaces. When the concave surface of the cathode sheet 30 and the convex surface of the anode sheet 40 are adjacent in the winding body, a perforation 411 is provided in the bending area 41a of the anode current collector 41. Lithium ions that escape from the concave surface of the cathode sheet 30 can be embedded in the convex surface of the adjacent anode sheet 40. Some lithium ions can be transported through the perforation 411 and embedded in the concave surface of the anode sheet 40, so that all lithium ions that escape from the concave surface of the cathode sheet 30 can be embedded inside the anode sheet 40, thereby improving the problem of lithium plating that easily occurs in the anode sheet 40 and improving the stability of the battery cell 20.

[0070] As for the case where the concave surface of the anode plate 40 is opposite to the convex surface of the cathode plate 30, the arc length of the concave surface of the anode plate 40 is originally greater than the arc length of the convex surface of the cathode plate 30. Generally, there is no problem with insufficient lithium intercalation capability of the anode. Even if some lithium ions on the convex surface of the anode plate 40 are transported through the perforated hole 411 and intercalated into the concave surface of the anode plate 40, it will not affect the lithium intercalation capability of the concave surface of the anode plate 40, and lithium plating will not occur on the concave surface of the anode plate 40.

[0071] According to some embodiments of this application, the anode current collector 41 is wound into multiple turns in a direction from the winding center axis close to the winding body to the winding center axis away from the winding body, and the hollow hole 411 is located at least in the bending area 41a of the anode current collector 41 closest to the winding center axis of the winding body.

[0072] From the winding center axis closest to the winding body to the winding center axis furthest from the winding body, the cathode plate 30 and the anode plate 40 are stacked and wound to form a multi-turn winding body. The number of turns of the anode current collector 41 can be the same as or different from the number of turns of the cathode plate 30.

[0073] The central axis of the winding body can be the axis of the winding center.

[0074] The perforated hole 411 is located at least in the bending region 41a of the innermost anode current collector 41. Exemplarily, the perforated hole 411 may be located only in the bending region 41a of the innermost anode current collector 41, or it may also be located in the bending regions 41a of the anode current collectors of other rings.

[0075] In the embodiments of this application, the difference in arc length between the convex surface of the anode plate 40 and the concave surface of the adjacent cathode plate 30 in the innermost ring of the bending region 41a is the largest, that is, the difference between the anode capacity and the cathode capacity is the largest. This makes the innermost ring of the anode plate 40 more prone to lithium plating compared to other rings. By setting the perforation 411 at least in the bending region 41a of the innermost ring of the anode current collector 41, the possibility of lithium plating in the anode plate 40 can be reduced, and the arrangement of the perforation 411 in other rings of the anode current collector 41 can be adjusted according to actual needs.

[0076] According to some embodiments of this application, the bending region 41a of the anode current collector 41 all have hollow holes 411.

[0077] In other words, each ring of anode current collector 41 located in the bending zone 41a is provided with a hollow hole 411.

[0078] In the embodiments of this application, this can reduce the possibility of lithium plating on the convex surface of the anode plate 40 in each turn, thereby improving the lithium plating problem of the battery cell 20 and increasing the reliability of the battery cell 20.

[0079] Figure 5 This is a schematic diagram of the structure of the bending area of ​​the wound body in some other embodiments of this application, with reference to... Figure 5 According to some embodiments of this application, the battery cell 20 further includes a conductive member 60, which is located at least within the hollow hole 411.

[0080] The conductive element 60 can be used to transfer lithium ions, allowing them to be smoothly transferred from the convex surface of the anode plate 40 to the concave surface of the anode plate 40. In some embodiments, the conductive element 60 can be an electrolyte material, an electrode material, or a membrane material, which facilitates the rapid transport of lithium ions within the perforated hole 411.

[0081] The conductive element 60 may be located only inside the hollow hole 411, or it may also be located on the anode current collector 41 at other locations besides the hollow hole 411.

[0082] The conductive element 60 can be located in part of the space within the hollow hole 411, or it can be located in the entire space within the hollow hole 411.

[0083] In some embodiments, screen printing or coating processes can be used to prepare the liquid conductive element 60 in the hollow hole 411 or at other locations outside the hollow hole 411, and then an anode active material can be coated on the surface of the anode current collector 41.

[0084] In the embodiments of this application, because a conductive element 60 is present within the perforated hole 411, when the active material is coated on the surface of the anode current collector 41, the active material is less likely to flow into the perforated hole 411 and block it. This also reduces the probability of the active material flowing out from the other end of the perforated hole 411, thereby reducing the possibility of active material contaminating the production equipment. Furthermore, the conductive element 60 facilitates the timely transport of lithium ions from the convex surface of the anode plate 40 to the concave surface of the anode plate 40, improving the lithium ion conduction efficiency and thus reducing the risk of lithium plating on the anode plate 40.

[0085] Figure 6 This is a top view of the anode current collector in some embodiments of this application. Figure 7 This is a cross-sectional view of the anode sheet in some embodiments of this application. (Reference) Figure 6 and Figure 7 According to some embodiments of this application, the anode current collector 41 has a plurality of hollow holes 411 arranged in an array, and the conductive member 60 is also located on both sides of the anode current collector 41. Along at least one of the row direction X and column direction Y of the arrayed hollow holes 411, the conductive member 60 in any two adjacent hollow holes 411 is connected to the conductive member 60 located on both sides of the anode current collector 41.

[0086] The anode current collector 41 may have multiple perforated holes 411 in a bending region 41a. The multiple perforated holes 411 may be arranged in a rectangular array, a linear array, or a circular array on the bending region 41a of the anode current collector 41.

[0087] The conductive element 60 is located not only inside the hollow hole 411, but also on at least a portion of the surface on both sides of the anode current collector 41.

[0088] In some embodiments, the X-direction of the array of perforated holes 411 is parallel to the length direction of the anode plate 40.

[0089] In some embodiments, the column direction Y of the arrayed perforated holes 411 is parallel to the width direction of the anode sheet 40.

[0090] In the embodiments of this application, along the row direction X of the array of perforated holes 411, the conductive element 60 inside the perforated hole 411 is connected to the conductive element 60 located on both sides of the anode current collector 41; or along the column direction Y of the array of perforated holes 411, the conductive element 60 inside the perforated hole 411 is connected to the conductive element 60 located on both sides of the anode current collector 41; or along both the row direction X and column direction Y of the array of perforated holes 411, the conductive element 60 inside the perforated hole 411 is connected to the conductive element 60 located on both sides of the anode current collector 41.

[0091] In some embodiments, the conductive elements 60 located on the surface of the anode current collector 41 may be arranged in horizontal stripes, vertical stripes, or a grid pattern, or may cover the entire bending area 41a.

[0092] In other words, the number of conductive elements 60 located on one side surface of the anode current collector 41 can be one or more.

[0093] The shapes of the conductive elements 60 located on both sides of the anode current collector 41 can be different or the same.

[0094] In the embodiments of this application, multiple hollow holes 411 are provided, and multiple conductive elements 60 are located within the hollow holes 411. This can improve the transfer efficiency of lithium ions from the convex surface of the anode plate 40 to the concave surface of the anode plate 40. In addition, the conductive elements 60 are also located on both sides of the anode current collector 41, which can increase the contact area between the conductive elements 60 and the anode active material layer 42. This facilitates the timely transfer of lithium ions in the anode active material layer 42 to the concave surface of the anode plate 40 through the conductive elements 60, thereby reducing the risk of lithium plating on the anode plate 40.

[0095] According to some embodiments of this application, along the row direction X, the conductive elements 60 in any two adjacent hollow holes 411 are connected by conductive elements 60 located on both sides of the anode current collector 41. The conductive elements 60 located on both sides of the anode current collector 41 extend along the row direction X. The column direction Y is the same as the width direction of the anode current collector 41, and the row direction X is perpendicular to the column direction Y.

[0096] In other words, when the anode plate 40 is laid out flat, the discharge direction X is the same as the length direction of the anode current collector 41.

[0097] In some embodiments, during the production of the electrode, the tape is carried along the length direction of the electrode, that is, the X-direction of the tape arrangement is consistent with the tape carrying direction of the electrode.

[0098] Understandably, the presence of a perforated hole 411 in the bending region 41a of the anode current collector 41 affects the tensile strength of the anode sheet 40, making it prone to breakage or strip breakage during tape feeding. By providing a conductive element 60 at least within the perforated hole 411, the tensile strength of the electrode sheet can be improved due to the good tensile strength of the conductive element 60, thereby reducing the possibility of electrode breakage or strip breakage and improving the reliability of the electrode sheet.

[0099] Tensile strength refers to the maximum stress that the conductive element 60 can withstand during tension. A tensile testing machine can be used to measure the tensile strength of the anode plate 40 before and after drilling, as well as the tensile strength of the anode plate 40 with the conductive element 60 installed.

[0100] In some embodiments, the two ends of the conductive member 60 extending along the row direction X may be opposite to the hollow hole 411, or they may be staggered.

[0101] In the embodiments of this application, the conductive element 60 is provided to extend along the row direction X, which simplifies the manufacturing process of the conductive element 60. In addition, it can also improve the tensile strength of the electrode and enhance the reliability of the electrode.

[0102] According to some embodiments of this application, along the column direction Y, the difference between the width W1 of the conductive element 60 located on both sides of the anode current collector 41 and the aperture D1 of the hollow hole 411 is greater than or equal to 0 and less than or equal to 0.5 mm.

[0103] The width direction of the conductive element 60, the width direction of the anode current collector 41, and the column direction Y are all the same.

[0104] In some embodiments, the width W1 of the conductive elements 60 located on both sides of the anode current collector 41 may be different or the same.

[0105] In some embodiments, the difference between the width W1 of the conductive element 60 on both sides of the anode current collector 41 and the aperture D1 of the hollow hole 411 can be 0, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm or 0.5 mm.

[0106] In the embodiments of this application, the hollow hole 411 is cylindrical in shape.

[0107] In the embodiments of this application, the conductive element 60 does not cover too much of the surface of the anode current collector 41, thereby increasing the contact area between the anode current collector 41 and the anode active material layer 42 and improving the current transmission performance of the battery cell 20.

[0108] According to some embodiments of this application, along the row direction X, the maximum spacing D2 between two hollow holes 411 is greater than or equal to 10 mm and less than or equal to 50 mm.

[0109] In other words, along the row direction X, the maximum width of the area of ​​the formed perforated holes 411 is greater than or equal to 10mm and less than or equal to 50mm. That is, the distance between the two farthest perforated holes 411 is greater than or equal to 10mm and less than or equal to 50mm.

[0110] In some embodiments, along the row direction X, the maximum spacing D2 between two hollow holes 411 can be 10mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm or 50mm.

[0111] It can be understood that, along the row direction X, when the spacing between any two adjacent perforated holes 411 is constant, the larger the maximum spacing D2 between the two perforated holes 411, the more perforated holes 411 there are.

[0112] In the embodiments of this application, along the row direction X, the area ratio of the multiple hollow holes 411 on the anode current collector 41 is not too large, so as not to reduce the surface area of ​​the anode current collector 41 and thus affect the electrical transmission performance of the battery cell 20, nor to reduce the transmission efficiency of lithium ions through the hollow holes 411 due to the number of hollow holes 411 being too small.

[0113] According to some embodiments of this application, along the column direction Y, the difference between the maximum spacing D3 between the two hollow holes 411 and the width W2 of the anode current collector 41 is greater than or equal to 0 and less than or equal to 5 mm.

[0114] In other words, along the column direction Y, the difference between the maximum length of the formed perforated hole 411 region and the width W2 of the anode current collector 41 is greater than or equal to 0 and less than or equal to 5 mm. That is, the difference between the distance between the two farthest perforated holes 411 and the width W2 of the anode current collector 41 is greater than or equal to 0 and less than or equal to 5 mm.

[0115] In some embodiments, along the column direction Y, the difference between the maximum spacing D3 between the two perforated holes 411 and the width W2 of the anode current collector 41 can be 0, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, or 5 mm.

[0116] Along the column direction Y, given a fixed spacing between any two adjacent perforated holes 411, a larger maximum spacing D3 between the two perforated holes 411 indicates a greater number of perforated holes 411. It can be understood that along the column direction Y, the maximum spacing D3 between two perforated holes 411 is equal to the width W2 of the anode current collector 41.

[0117] In the embodiments of this application, along the column direction Y, the area ratio of multiple hollow holes 411 on the anode current collector 41 is relatively large, that is, the number of hollow holes 411 is large, which can improve the efficiency of lithium ion transfer from the convex surface of the anode plate 40 to the concave surface of the anode plate 40 and reduce the risk of lithium plating on the anode plate 40.

[0118] According to some embodiments of this application, the thickness D4 of the conductive element 60 located on both sides of the anode current collector 41 is greater than or equal to 0.5 μm and less than or equal to 3 μm (micrometers).

[0119] The thickness direction of the conductive element 60 is perpendicular to the direction of the winding center axis.

[0120] In some embodiments, the thickness D4 of the conductive element 60 located on both sides of the anode current collector 41 can be 0.5μm, 0.7μm, 0.9μm, 1.1μm, 1.3μm, 1.5μm, 1.7μm, 2.0μm, 2.3μm, 2.6μm or 3μm.

[0121] In some embodiments, the thickness D4 of the conductive elements 60 located on both sides of the anode current collector 41 may be different or the same.

[0122] In some embodiments, the thickness D4 of the conductor 60 located on one side surface of the anode current collector 41 may be the same everywhere or not be exactly the same.

[0123] In some embodiments, the thickness D4 of the conductive element 60 located on the surface of the anode current collector 41 can be measured using SEM (Scanning Electron Microscope).

[0124] In the embodiments of this application, this allows the conductive element 60 to have good ion conduction performance while reducing the space it occupies, increasing the volume of the anode active material layer 42 coated on the surface of the anode current collector 41, thereby increasing the energy density of the battery cell 20.

[0125] According to some embodiments of this application, the material of the conductive element 60 includes one of polyethylene (PE), polypropylene (PP), polyvinylidene fluoride (PVDF) and hexafluoropropylene (HFP) copolymer, polyacrylamide (PAM), polyacrylonitrile (PAN), or polyvinyl alcohol (PVA).

[0126] The aforementioned material is an electrolyte retention material, meaning that the material can absorb the electrolyte in the electrode assembly 23.

[0127] The above materials also have good tensile strength.

[0128] In the embodiments of this application, the conductive element 60 can absorb electrolyte, thereby forming a good ion conduction path in the hollow hole 411 and improving the lithium ion transfer efficiency. In addition, the conductive element 60 also has good tensile strength, which can reduce the risk of the anode sheet 40 breaking or strip breaking during electrode rolling or other processes.

[0129] As an example, Table 1 below shows the number of charge-discharge cycles for the eight battery cells 20 at 80% SOC (State of Charge), and the lithium plating situation occurring in the bending region 41a of the anode sheet 40. Among the eight battery cells 20, the aperture D1 of the perforated holes 411 differs, the spacing D5 between adjacent perforated holes 411 differs, the material of the conductive element 60 differs, or the thickness D4 of the conductive element 60 differs. The material of the conductive element 60 includes polyvinylidene fluoride-hexafluoropropylene copolymer, polypropylene, or polyethylene. No lithium plating means the interface is golden yellow with no silvery-white lithium metal deposits. Slight lithium plating means the interface is a state where golden yellow coexists with specks of silvery-white lithium metal. Severe lithium plating means the interface is a state where golden yellow coexists with large areas of silvery-white lithium metal.

[0130] Table 1

[0131]

[0132] As shown in Table 1, when the anode current collector 41 is not provided with a perforation 411, the state of charge (SOC) decays to 80% after 1500 charge-discharge cycles, and severe lithium plating occurs in the bending region 41a. In Group 2, by providing a perforation 411 on the anode current collector 41, the degree of lithium plating in the bending region 41a is less severe than when the anode current collector 41 is not provided with a perforation 411. Furthermore, in Groups 3 to 8, by simultaneously providing a perforation 411 and a conductive element 60 on the anode current collector 41, and controlling the aperture D1 of the perforation 411, the spacing D5 between adjacent perforations 411, the material of the conductive element 60, and the thickness D4 of the conductive element 60, the degradation of the battery cell 20 can be slowed down, and the lithium plating problem in the bending region 41a can be improved. For example, the battery cells 20 corresponding to Group 3, Group 5 and Group 8 can only have their SOC decay to 80% after 2000 charge-discharge cycles, and there is no lithium plating in the bending region 41a, which effectively reduces the decay rate of the battery cells 20 and improves the performance of the battery cells 20.

[0133] According to some embodiments of this application, the diameter D1 of the perforated hole 411 is greater than or equal to 1 mm and less than or equal to 5 mm.

[0134] The diameter D1 of the perforated hole 411 on the anode current collector 41 can be equal everywhere or not completely equal.

[0135] In some embodiments, the aperture D1 of the perforated hole 411 can be 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm or 5mm.

[0136] In some embodiments, the aperture D1 of the formed perforated hole 411 can be measured using an optical CCD (Charge Coupled Device) or SEM.

[0137] In the embodiments of this application, the aperture D1 of the hollow hole 411 is maintained within the above-mentioned range, so that the aperture D1 of the hollow hole 411 is large enough to facilitate the placement of the conductive element 60 in the hole and allow lithium ions to pass smoothly through the hollow hole 411 to be embedded in the concave surface of the anode plate 40; at the same time, the aperture D1 of the hollow hole 411 will not be too large and occupy the surface area of ​​the anode current collector 41, thus affecting the electrical transmission performance of the battery cell 20.

[0138] According to some embodiments of this application, the anode current collector 41 has a plurality of hollow holes 411, and the spacing D5 between any adjacent hollow holes 411 is greater than or equal to 1 mm and less than or equal to 5 mm.

[0139] In some embodiments, the spacing D5 between any two adjacent perforated holes 411 can be 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm or 5mm.

[0140] In some embodiments, an optical CCD or SEM can be used to measure the distance D5 between adjacent perforated holes 411.

[0141] In the embodiments of this application, the spacing D5 between any adjacent perforations 411 is maintained within the aforementioned range, enabling a larger number of perforations 411 to be provided within the limited area of ​​the bending region 41a of the anode sheet 40, thereby improving the lithium-ion transport efficiency and reducing the risk of lithium plating on the anode sheet 40. Simultaneously, this also ensures that the spacing D5 between any adjacent perforations 411 is not too small, thus facilitating the provision of perforations 411 on the surface of the anode current collector 41.

[0142] This application provides a battery device, which includes the battery cell 20 in the above embodiments.

[0143] The battery device can be referred to the relevant description in the above embodiments, and will not be repeated here.

[0144] The battery device has the beneficial effects of the battery cell 20 provided in the embodiments of this application. For details, please refer to the specific description of the battery cell 20 in the above embodiments, which will not be repeated here.

[0145] This application provides an electrical device, which includes the battery device described in the above embodiments, and the battery device is used to provide electrical energy.

[0146] The electrical device has the beneficial effects of the battery device provided in the embodiments of this application. For details, please refer to the specific descriptions of the battery device in the above embodiments, which will not be repeated here.

[0147] This application provides an energy storage device, which includes the battery device described in the above embodiments, and the battery device is used to store electrical energy.

[0148] The energy storage device has the beneficial effects of the battery device provided in the embodiments of this application. For details, please refer to the specific descriptions of the battery device in the above embodiments, which will not be repeated here.

[0149] This application provides a battery cell 20, which includes a cathode sheet 30 and an anode sheet 40, which are stacked and wound to form a wound body. The anode sheet 40 includes an anode current collector 41 and an anode active material layer 42 located on both sides of the anode current collector 41. The anode current collector 41 has a bending region 41a and a perforation 411 located in the bending region 41a, and the anode active material layer 42 covers the perforation 411. The anode current collector 41 is wound to form multiple turns in a direction from the winding center axis close to the wound body to the winding center axis away from the wound body, and the perforation 411 is located at least in the bending region 41a of the anode current collector 41 closest to the winding center axis of the wound body.

[0150] The battery cell 20 also includes a conductive element 60, which is located at least within the perforated holes 411. The anode current collector 41 has multiple perforated holes 411 arranged in an array. The conductive elements 60 are also located on both sides of the anode current collector 41. Along the row direction X of the arrayed perforated holes 411, the conductive elements 60 in any two adjacent perforated holes 411 are connected by the conductive elements 60 located on both sides of the anode current collector 41. The conductive elements 60 located on both sides of the anode current collector 41 extend along the row direction X. The column direction Y is the same as the width direction of the anode current collector 41, and the row direction X is perpendicular to the column direction Y.

[0151] Along the column direction Y, the difference between the width W1 of the conductive element 60 on both sides of the anode current collector 41 and the aperture D1 of the perforated hole 411 is equal to 0. Along the row direction X, the maximum distance D2 between two perforated holes 411 is greater than or equal to 10 mm and less than or equal to 50 mm. Along the column direction Y, the difference between the maximum distance D3 between two perforated holes 411 and the width W2 of the anode current collector 41 is equal to 0. The thickness D4 of the conductive element 60 on both sides of the anode current collector 41 is greater than or equal to 0.5 μm and less than or equal to 3 μm. The material of the conductive element 60 includes one of polyethylene, polypropylene, polyvinylidene fluoride and hexafluoropropylene copolymer, polyacrylamide, polyacrylonitrile, or polyvinyl alcohol. The aperture D1 of the perforated hole 411 is greater than or equal to 1 mm and less than or equal to 5 mm. The anode current collector 41 has multiple perforated holes 411, and the distance D5 between any adjacent perforated holes 411 is greater than or equal to 1 mm and less than or equal to 5 mm.

[0152] 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: Cathode plate (30); The anode sheet (40) includes an anode current collector (41) and an anode active material layer (42) located on both sides of the anode current collector (41). The cathode sheet (30) and the anode sheet (40) are stacked and wound to form a wound body. The anode current collector (41) has a bending area (41a). The anode current collector (41) also has a perforated hole (411), the anode active material layer (42) covers the perforated hole (411), and the perforated hole (411) is located in the bending area (41a).

2. The battery cell according to claim 1, characterized in that, The anode current collector (41) is wound in multiple turns from the winding center axis near the winding body to the winding center axis away from the winding body, and the perforated hole (411) is located at least in the bending area (41a) of the anode current collector (41) closest to the winding center axis of the winding body.

3. The battery cell according to claim 1 or 2, characterized in that, The bending area (41a) of the anode current collector (41) has the hollow hole (411).

4. The battery cell according to any one of claims 1 to 3, characterized in that, The battery cell also includes: A conductive element (60) is located at least within the hollow hole (411).

5. The battery cell according to claim 4, characterized in that, The anode current collector (41) has a plurality of hollow holes (411) arranged in an array. The conductive element (60) is also located on both sides of the anode current collector (41). Along at least one of the row direction and column direction of the arrayed hollow holes (411), the conductive element (60) in any two adjacent hollow holes (411) is connected to the conductive element (60) located on both sides of the anode current collector (41).

6. The battery cell according to claim 5, characterized in that, Along the row direction, the conductive element (60) in any two adjacent hollow holes (411) is connected by the conductive element (60) located on both sides of the anode current collector (41). The conductive element (60) located on both sides of the anode current collector (41) extends along the row direction. The column direction is the same as the width direction of the anode current collector (41), and the row direction is perpendicular to the column direction.

7. The battery cell according to claim 6, characterized in that, Along the column direction, the difference between the width of the conductive element (60) located on both sides of the anode current collector (41) and the diameter of the perforated hole (411) is greater than or equal to 0 and less than or equal to 0.5 mm.

8. The battery cell according to claim 6 or 7, characterized in that, Along the row direction, the maximum distance between the two hollow holes (411) is greater than or equal to 10 mm and less than or equal to 50 mm.

9. The battery cell according to any one of claims 6 to 8, characterized in that, Along the column direction, the difference between the maximum spacing between the two hollow holes (411) and the width of the anode current collector (41) is greater than or equal to 0 and less than or equal to 5 mm.

10. The battery cell according to any one of claims 5 to 9, characterized in that, The thickness of the conductive element (60) located on both sides of the anode current collector (41) is greater than or equal to 0.5 μm and less than or equal to 3 μm.

11. The battery cell according to any one of claims 4 to 10, characterized in that, The material of the conductive element (60) includes one of polyethylene, polypropylene, polyvinylidene fluoride and hexafluoropropylene copolymer, polyacrylamide, polyacrylonitrile or polyvinyl alcohol.

12. The battery cell according to any one of claims 1 to 11, characterized in that, The diameter of the perforated hole (411) is greater than or equal to 1 mm and less than or equal to 5 mm.

13. The battery cell according to any one of claims 1 to 12, characterized in that, The anode current collector (41) has a plurality of the hollow holes (411), and the spacing between any adjacent hollow holes (411) is greater than or equal to 1 mm and less than or equal to 5 mm.

14. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-13.

15. An electrical appliance, characterized in that, The electrical device includes the battery device as described in claim 14, the battery device being used to provide electrical energy.

16. An energy storage device, characterized in that, The energy storage device includes the battery device as described in claim 14, the battery device being used to store electrical energy.

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