Battery cell, related device, system and charging network

Abstract

The utility model is suitable for the technical field of power batteries, and provides a battery monomer, a related device, a system and a charging network. The battery monomer comprises a pole piece, the pole piece comprises a current collector, the current collector comprises two end faces and two side faces, and protruding structures are formed on the end faces; and the insulating layer is arranged on the current collector and at least covers the end surface and the convex structure. In the battery monomer provided by the embodiment of the invention, the convex structure is formed on the end surface of the current collector, and the convex structure is easy to pierce the diaphragm adjacent to the pole piece and causes short circuit of the two adjacent pole pieces, so that the short circuit of the battery monomer is caused; accordingly, the insulating layer is arranged, the protruding structure is covered by the insulating layer, the protruding structure is wrapped by the insulating layer, and the position of the protruding structure is fixed, so that the risk that the protruding structure pierces the adjacent diaphragms is reduced, the risk of short circuit of the adjacent pole pieces can be reduced, and the safety and stability of the battery monomer can be improved.

Description

Technical Field

[0001] The present application belongs to the field of power battery technology, and in particular relates to a battery cell, related devices, systems and charging networks. Background Art

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

[0003] During the battery manufacturing process, the pole pieces need to be die-cut to form pole ears. After die-cutting, burrs are likely to form on the cross-section of the pole pieces. The burrs can easily penetrate the diaphragm and cause short circuits between adjacent pole pieces, leading to a short circuit and an increased risk of thermal runaway of the battery. Utility Model Content

[0004] In view of the above problems, the present application provides a battery cell, related devices, system and charging network, which can alleviate the problem of burrs piercing the diaphragm and causing short circuit of adjacent pole pieces.

[0005] In a first aspect, some embodiments of the present application provide a battery cell, including a pole piece, the pole piece including: a current collector, the current collector including two end faces located at opposite ends along the width direction of the current collector, the current collector also including two side faces located at opposite sides along the thickness direction of the current collector, a protruding structure formed on the end face; an insulating layer, provided on the current collector, the insulating layer covering at least the end face and the protruding structure.

[0006] In the technical solution of this embodiment, a protruding structure is formed on the end face of the current collector, and the protruding structure can easily pierce the diaphragm adjacent to the electrode and cause a short circuit between the two adjacent electrode sheets, thereby causing a short circuit in the battery cell. Accordingly, an insulating layer is provided, and the protruding structure is covered by the insulating layer. The protruding structure is wrapped by the insulating layer and the position of the protruding structure is fixed to reduce the risk of the protruding structure piercing the adjacent diaphragm, thereby reducing the risk of short circuit between adjacent electrode sheets and improving the safety and stability of the battery cell.

[0007] In some embodiments, the insulating layer wraps around the protruding structure.

[0008] In the technical solution of this embodiment, the insulating layer wraps the protruding structure so that the protruding structure is not easily pierced by the insulating layer. At the same time, the insulating layer wrapping the protruding structure can also play a role in fixing the protruding structure so that the protruding structure is not easily swung relative to the current collector and pierced the diaphragm.

[0009] In some embodiments, the thickness of the insulating layer ranges from 9 μm to 30 μm.

[0010] The technical solution of this embodiment provides a thickness range for the insulating layer, so that the thickness of the insulating layer is greater than or equal to 9μm. After the insulating layer covers the protruding structure, the insulating layer in this thickness range can better cover the protruding structure and have a certain strength, so that the protruding structure is difficult to pierce the insulating layer, thereby reducing the risk of the protruding structure piercing the adjacent diaphragm, reducing the risk of short circuiting of adjacent pole pieces, and improving the safety and stability of the battery cell; the thickness of the insulating layer is less than or equal to 30μm. Under the premise that the protruding structure is difficult to pierce the insulating layer, this setting can limit the thickness of the insulating layer so that the thickness of the insulating layer is not too large, thereby reducing the negative impact of the insulating layer on the energy density of the battery cell.

[0011] In some embodiments, the insulating layer has a needle punch strength greater than or equal to 300 gf.

[0012] The technical solution of this embodiment provides some puncture strength ranges for the insulating layer, so that the protruding structure is difficult to pierce the insulating layer, thereby enabling the insulating layer to better reduce the risk of short circuit between the protruding structure and the adjacent electrode.

[0013] In some embodiments, the protrusion structure includes at least two first protrusions spaced apart along the length direction of the current collector, the first protrusions being formed on the end surface; and the insulating layer covering the first protrusions.

[0014] The technical solution of this embodiment provides some specific structures of the protruding structure, so that the protruding structure includes first protruding parts arranged at intervals, and the insulating layer can cover the first protruding parts, so that the insulating layer can adapt to the structure of the first protruding parts.

[0015] In some embodiments, the length of the first protrusion ranges from 40 μm to 200 μm.

[0016] The technical solution of this embodiment provides some size ranges of the first protrusions and enables the insulating layer to adapt to the structure of the first protrusions, so that the insulating layer can cover first protrusions of different sizes, thereby making it difficult for protrusion structures of different sizes to pierce the insulating layer.

[0017] In some embodiments, in the length direction of the current collector, the number of the first protrusions within a size range of 1 mm is greater than or equal to 1; and the thickness of the insulating layer is in a range of 13 μm to 30 μm.

[0018] The technical solution of this embodiment provides some arrangement structures of the first protrusions and specific thickness ranges of the corresponding insulating layers, so that the insulating layer can better adapt to the size and arrangement structure of the first protrusions, thereby enabling the insulating layer to better cover the first protrusions and making it difficult for the first protrusions to pierce the insulating layer.

[0019] In some embodiments, the protruding structure also includes a plurality of second protrusions spaced apart along the length direction of the current collector, and a connecting portion is provided between two adjacent second protrusions, and the connecting portion and the second protrusion are both formed on the end surface; the length of the connecting portion is less than the length of the second protrusion; and the insulating layer covers the second protrusion and the connecting portion.

[0020] The technical solution of this embodiment provides some specific structures of the protruding structure, so that the protruding structure includes second protruding parts arranged at intervals, and connecting parts are provided between adjacent second protruding parts; the insulating layer can cover the second protruding parts so that the insulating layer can adapt to the structure of the second protruding parts.

[0021] In some embodiments, the length of the second protrusion ranges from 15 μm to 40 μm.

[0022] The technical solution of this embodiment provides some size ranges of the second protrusions and enables the insulating layer to adapt to the structure of the second protrusions, so that the insulating layer can cover second protrusions of different sizes, thereby making it difficult for protrusion structures of different sizes to pierce the insulating layer.

[0023] In some embodiments, in the length direction of the current collector, the number of the second protrusions within a size range of 1 mm is in a range of 3 to 5; and the thickness of the insulating layer is in a range of 9 μm to 13 μm.

[0024] The technical solution of this embodiment provides some arrangement structures of the second protrusions and specific thickness ranges of the corresponding insulating layers, so that the insulating layer can better adapt to the size and arrangement structure of the second protrusions, thereby enabling the insulating layer to better cover the second protrusions and making it difficult for the second protrusions to pierce the insulating layer.

[0025] In some embodiments, in the length direction of the current collector, the number of the second protrusions within a size range of 1 mm is in a range of 5 to 15; and the thickness of the insulating layer is in a range of 13 μm to 30 μm.

[0026] The technical solution of this embodiment provides other arrangement structures of the second protrusions and specific thickness ranges of the corresponding insulating layers, so that the insulating layer can better adapt to the size and arrangement structure of the second protrusions, thereby enabling the insulating layer to better cover the second protrusions and making it difficult for the second protrusions to pierce the insulating layer.

[0027] In some embodiments, the insulating layer includes two sub-insulating layers corresponding to the two side surfaces, the sub-insulating layer includes a first part and a second part connected to the first part, and the second part is connected to the side surface; at least a portion of the first part is connected to the first part of another adjacent sub-insulating layer, and the two first parts clamp the protruding structure to guide the protruding structure to extend along the width direction of the current collector.

[0028] The technical solution of this embodiment provides some specific structures of the insulating layer, so that the insulating layer is formed by two sub-insulating layers connected to each other; the sub-insulating layer includes a first part and a second part, and the two first parts clamp the protruding structure to guide and limit the extension direction of the protruding structure through the two first parts, so that the protruding structure is not easy to bend to both sides and pierce the sub-insulating layer or the adjacent diaphragm.

[0029] In some embodiments, a size of the first portion in a width direction of the current collector ranges from 0.2 mm to 6 mm.

[0030] The technical solution of this embodiment provides some size ranges for the first part, so that the first part can not only better cover the protruding structure to reduce the risk of the protruding structure piercing the insulating layer, but also reduce the first part's occupation of the internal space of the battery cell and reduce the negative impact of the insulating layer on the energy density of the battery cell.

[0031] In some embodiments, the electrode further includes an active material layer disposed on a side surface, the active material layer covering at least a portion of the side surface; and the sub-insulating layer is connected to the active material layer.

[0032] In the technical solution of this embodiment, the sub-insulating layer is connected to the active material layer so that the sub-insulating layer can be more stably connected to the pole piece and cover the protruding structure, thereby improving the stability of the insulating layer and reducing the risk of structural failure caused by the insulating layer falling off.

[0033] In some embodiments, the active material layer covers part of the side surface and forms a blank area on one side of the side surface close to the end surface, and the second part covers at least part of the blank area.

[0034] In the technical solution of this embodiment, the second portion can cover at least part of the blank area to protect the current collector, while also reducing the area of ​​the current collector exposed to the outside, thereby reducing the occurrence of short circuits and improving the safety performance of the battery cell.

[0035] In some embodiments, the size of the blank area in the width direction of the current collector is less than or equal to 5 mm.

[0036] The technical solution of this embodiment provides a range of sizes of some blank areas, so that the sub-insulating layer can be more stably connected to the current collector through the second part, while also reducing the negative impact of the blank areas on the coverage area of ​​the active material layer, thereby reducing the negative impact of the blank areas on the charge and discharge capacity of the electrode.

[0037] In some embodiments, the sub-insulating layer further includes a third portion connected to a side of the second portion opposite to the first portion, the second portion covers the blank area, and the third portion covers a portion of the active material layer.

[0038] In the technical solution of this embodiment, the sub-insulating layer further includes a third portion, and the third portion covers a portion of the active material layer, so that the second portion can completely cover the blank area, thereby further improving the safety performance of the battery cell.

[0039] In some embodiments, the active material layer includes a main body and a transition portion connected to the main body, the transition portion is arranged on the side of the main body facing the end face, and the thickness of the transition portion gradually decreases along the direction from the main body to the end face; the third portion covers at least part of the transition portion.

[0040] In the technical solution of this embodiment, the active material layer includes a transition portion with a gradually decreasing thickness, and the third portion covers at least a portion of the transition portion to reduce the height of the third portion protruding from the active material layer, thereby reducing the negative impact of the insulating layer on the energy density of the battery cell and further alleviating the stress concentration of the electrode at the insulating layer.

[0041] In some embodiments, a dimension of the third portion in the width direction of the current collector ranges from 0.1 mm to 1 mm.

[0042] The technical solution of this embodiment provides some size ranges of the third part, so that the third part can be more stably connected to the transition part and not easily fall off, so that the second part can better cover the blank area, reducing the risk of short circuit and damage caused by the exposure of the blank area; at the same time, this setting can also make the third part less likely to protrude from the plane where the surface of the active material layer is away from the corresponding side, or can reduce the height of the third part protruding from the plane where the surface of the active material layer is away from the corresponding side, so as to reduce the stress concentration at the third part during the winding and hot pressing process, thereby reducing the possible damage to the electrode.

[0043] In some embodiments, the sub-insulating layer includes a substrate layer and an adhesive layer disposed on the substrate layer, wherein the adhesive layer is disposed on a side of the substrate layer facing the current collector.

[0044] The technical solution of this embodiment provides some sub-insulating layer structures, so that the sub-insulating layer includes an adhesive layer and a substrate layer, so that the substrate layer can be connected to the current collector through the adhesive layer, and can cover the protruding structure through the adhesive layer, and make it difficult for the protruding structure to pierce the insulating layer through the substrate layer; at the same time, the substrate layer can also play a role in protecting the current collector.

[0045] In some embodiments, the substrate layer is an insulating structural layer.

[0046] In the technical solution of this embodiment, the substrate layer is an insulating structure layer to reduce the risk of current collector short circuit.

[0047] In some embodiments, the thickness of the substrate layer ranges from 6 μm to 20 μm.

[0048] The technical solution of this embodiment provides a certain thickness range of the substrate layer, so that the protruding structure is difficult to pierce the substrate layer, and the substrate layer can provide protection for the current collector; this setting can also make the substrate layer less likely to be broken down by static electricity, so that the substrate layer can better provide protection for the current collector.

[0049] In some embodiments, the adhesive layer is an adhesive structural layer.

[0050] In the technical solution of this embodiment, the adhesive layer is a viscous structural layer to bond the substrate layer to the current collector and / or active material layer; at the same time, the adhesive layer can also cover the protruding structure to reduce the risk of the protruding structure piercing the insulating layer.

[0051] In some embodiments, the thickness of the adhesive layer ranges from 3 μm to 10 μm.

[0052] The technical solution of this embodiment provides some thickness ranges of the adhesive layer, so that the adhesive layer can more stably bond the substrate layer to the current collector and / or active material layer, and at the same time, the adhesive layer can also prevent the protruding structure from piercing the insulating layer.

[0053] In some embodiments, the insulating layer has a size ranging from 0.3 mm to 12 mm in the width direction of the current collector.

[0054] The technical solution of this embodiment provides a width range of some insulating layers so that the insulating layer can not only cover the protruding structure but also be stably connected to the current collector and / or active material layer; at the same time, it can also reduce the space occupied by the insulating layer and reduce the negative impact of the insulating layer on the energy density of the battery cell.

[0055] In some embodiments, the peel strength of the insulating layer ranges from 15 N / m to 20 N / m.

[0056] The technical solution of this embodiment provides some peel strength ranges for the insulating layer, so that the insulating layer is difficult to separate from the current collector and / or active material layer, thereby enabling the insulating layer to still have strong connection stability in an electrolyte infiltration environment.

[0057] In some embodiments, the battery cell further includes an electrode assembly, which includes a positive electrode sheet, a separator, and a negative electrode sheet that are sequentially spaced apart; the electrode sheet is a positive electrode sheet.

[0058] In the technical solution of this embodiment, the hazards caused by the short circuit between the protruding structure generated by the processing of the positive electrode sheet and the active material layer of the negative electrode sheet are greater, so this embodiment uses the electrode sheet as a positive electrode sheet to reduce the safety risk caused by the short circuit of the protruding structure.

[0059] In a second aspect, some embodiments of the present application further provide a battery device, comprising the battery cell provided by some embodiments of the first aspect.

[0060] In a third aspect, some embodiments of the present application further provide an energy storage device, comprising a plurality of battery cells provided by some embodiments of the first aspect, or a plurality of battery devices provided by some embodiments of the second aspect;

[0061] Battery cells or battery devices are used to store or provide electrical energy.

[0062] In a fourth aspect, some embodiments of the present application further provide an energy storage system, comprising a power conversion device and the energy storage device provided by some embodiments of the third aspect, wherein the power conversion device is used to electrically connect the power generation device and the energy storage device.

[0063] In a fifth aspect, some embodiments of the present application also provide an electrical device, characterized in that it includes a battery cell provided by some embodiments of the first aspect, a battery device provided by some embodiments of the second aspect, an energy storage device provided by some embodiments of the third aspect, or an energy storage system provided by some embodiments of the fourth aspect, and the battery cell or battery device is used to store or provide electrical energy.

[0064] In a sixth aspect, some embodiments of the present application further provide a charging network, comprising a charging pile and an energy storage device provided by some embodiments of the third aspect, or an energy storage system provided by some embodiments of the fourth aspect; the energy storage device or the energy storage system is used to provide electrical energy for the charging pile.

[0065] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0067] Figure 1 A schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0068] Figure 2 Schematic diagram of the exploded structure of a battery device according to some embodiments of the present application;

[0069] Figure 3 A schematic diagram of the exploded structure of a battery cell according to some embodiments of the present application;

[0070] Figure 4A schematic diagram of the structure of an electrode assembly provided in some embodiments of the present application;

[0071] Figure 5 A schematic cross-sectional view of an electrode assembly provided in some embodiments of the present application;

[0072] Figure 6 A schematic diagram of the structure of the pole piece provided in some embodiments of the present application;

[0073] Figure 7 for Figure 6 A partial enlarged schematic diagram after the insulation layer is removed at point A in the middle;

[0074] Figure 8 for Figure 6 Schematic cross-sectional view at the midline BB;

[0075] Figure 9 In some embodiments of this application Figure 6 Schematic cross-sectional view at the midline CC;

[0076] Figure 10 In other embodiments of this application Figure 6 Schematic cross-sectional view at the midline CC;

[0077] Figure 11 for Figure 8 A partial enlarged schematic diagram of point D in the middle;

[0078] Figure 12 for Figure 8 A partial enlarged schematic diagram of point E in the middle;

[0079] Figure 13 A schematic diagram of the structure of an energy storage system provided in some embodiments of the present application;

[0080] Figure 14 A schematic diagram of the structure of a charging network provided in some embodiments of the present application.

[0081] The meanings of the marks in the figure are:

[0082] 1. Energy storage device; 2. Power conversion device; 3. Power generation device; 4. Charging pile; 5. Connector;

[0083] 1000. Battery device;

[0084] 100. Battery cell;

[0085] 10. Electrode assembly; 11. Pole piece; 111. Current collector; 1111. Current collector body; 1111a. End face; 1111b. Side face; 1111c. Blank area; 1112. Protrusion structure; 1112a. First protrusion; 1112b. Second protrusion; 1112c. Connecting portion; 1113. Ear portion; 112. Insulating layer; 1121. Sub-insulating layer; 1121a. First portion; 1121b. Second portion; 1121c. Third portion; 1121d. Base material layer; 1121e. Adhesive layer; 113. Active material layer; 1131. Main body; 1132. Transition portion; 114. Positive electrode piece; 115. Negative electrode piece; 12. Separator;

[0086] 20. Housing;

[0087] 30. End cap;

[0088] 40. Electrode terminal;

[0089] 200, box body; 201, upper box body; 202, lower box body;

[0090] 2000, motor;

[0091] 3000, controller. DETAILED DESCRIPTION

[0092] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0093] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0094] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0095] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0096] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0097] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0098] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0099] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0100] Currently, market developments indicate that power batteries are becoming increasingly widely used. They are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric vehicles, as well as in military equipment and aerospace. As power battery applications continue to expand, market demand is also growing.

[0101] During the battery manufacturing process, the pole pieces need to be die-cut to form the tabs. Burrs are prone to forming on the cross-section of the pole pieces after die-cutting. These burrs can easily pierce adjacent separators and contact adjacent pole pieces, causing a short circuit between adjacent pole pieces. This can negatively impact battery performance and increase the risk of thermal runaway.

[0102] In order to alleviate the problem of burrs piercing the diaphragm and causing short circuits between adjacent pole pieces, the number of burrs generated can be reduced during the pole piece cutting process, but this requires improvements to the winding and die-cutting equipment, which is too costly and difficult to eliminate the burrs. A small amount of burrs on the pole piece cross section still poses the risk of piercing the diaphragm and causing short circuits between adjacent pole pieces.

[0103] Based on the above considerations, in order to alleviate the problem of burrs piercing the diaphragm and causing short circuit of adjacent pole pieces, an embodiment of the present application provides a battery cell. Since the protruding structure is located on the end face of the current collector, an insulating layer is provided to cover the end face of the current collector, and the protruding structure is covered by the insulating layer.

[0104] In such a battery cell, the protruding structure is located on the end face of the current collector, so that the position of the protruding structure is relatively concentrated and determined, thereby facilitating the setting of an insulating layer; an insulating layer is set, and the protruding structure is covered by the insulating layer, and the protruding structure is wrapped by the insulating layer and the position of the protruding structure is fixed to reduce the risk of the protruding structure piercing the adjacent diaphragm, thereby reducing the risk of short-circuiting adjacent pole pieces and improving the safety and stability of the battery cell.

[0105] The battery cells disclosed in the embodiments of the present application can be used in electrical devices that use the battery device as a power source or various energy storage systems that use the battery device as an energy storage element. The electrical devices may be, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, battery-powered vehicles, electric vehicles, ships, spacecraft, and the like. Among them, electric toys may include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and the like, and spacecraft may include airplanes, rockets, space shuttles, and spacecraft, and the like.

[0106] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device according to an embodiment of the present application.

[0107] refer to Figure 1 , Figure 1The power-consuming device provided for some embodiments of the present application is a schematic structural diagram of a vehicle. The vehicle can be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery device 1000 is provided inside the vehicle, and the battery device 1000 can be provided at the bottom, head or tail of the vehicle. The battery device 1000 can be used to power the vehicle, for example, the battery device 1000 can serve as an operating power source for the vehicle. The vehicle may also include a controller 3000 and a motor 2000, and the controller 3000 is used to control the battery device 1000 to power the motor 2000, for example, for starting, navigating and operating power requirements of the vehicle during driving.

[0108] In some embodiments of the present application, the battery device 1000 can serve not only as an operating power source for the vehicle, but also as a driving power source for the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0109] refer to Figure 2 , Figure 2 Schematic diagram of an exploded structure of a battery device 1000 provided in some embodiments of the present application. The battery device 1000 includes a housing 200 and a battery cell 100, with the battery cell 100 housed within the housing 200. The housing 200 is used to provide a storage space for the battery cell 100, and the housing 200 can adopt a variety of structures. In some embodiments, the housing 200 can include an upper housing 201 and a lower housing 202, which cover each other and together define a storage space for the battery cell 100. The lower box body 202 may be a hollow structure with one end open, and the upper box body 201 may be a plate-like structure, with the upper box body 201 covering the open side of the lower box body 202, so that the upper box body 201 and the lower box body 202 jointly define a storage space. The upper box body 201 and the lower box body 202 may also be hollow structures with one end open, with the open side of the upper box body 201 covering the open side of the lower box body 202. Of course, the box body 200 formed by the upper box body 201 and the lower box body 202 may have various shapes, such as a cylinder, a rectangular parallelepiped, etc.

[0110] In the battery device 1000, there may be multiple battery cells 100, and the multiple battery cells 100 may be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 100. The multiple battery cells 100 may be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery unit formed by the multiple battery cells 100 may be housed within the housing 200. Of course, the battery device 1000 may also be a battery module formed by first connecting multiple battery cells 100 in series, in parallel, or in a hybrid connection, and then the multiple battery modules are further connected in series, in parallel, or in a hybrid connection to form an entire battery unit, which is then housed within the housing 200. The battery device 1000 may also include other structures, for example, the battery device 1000 may further include a busbar component for achieving electrical connection between the multiple battery cells 100.

[0111] Each battery cell 100 may be a secondary battery or a primary battery; it may also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 100 may be cylindrical, flat, rectangular, or in other shapes.

[0112] refer to Figure 3 The battery cell 100 is the smallest unit constituting the battery device 1000. The battery cell 100 includes an end cap 30, a housing 20, an electrode assembly 10, and other functional components.

[0113] The end cap 30 is a component that covers the opening of the housing 20 to isolate the internal environment of the battery cell 100 from the external environment. The shape of the end cap 30 can be adapted to the shape of the housing 20 to fit the housing 20. Optionally, the end cap 30 can be made of a material with a certain hardness and strength (such as an aluminum alloy). This prevents the end cap 30 from deforming when subjected to compression or collision, thereby providing the battery cell 100 with greater structural strength and improved safety. Functional components such as electrode terminals 40 can be provided on the end cap 30. The electrode terminals 40 can be used to electrically connect to the electrode assembly 10 for inputting or outputting electrical energy to or from the battery cell 100. In some embodiments, the end cap 30 can also be provided with a pressure relief mechanism for relieving internal pressure when the internal pressure or temperature of the battery cell 100 reaches a threshold. The end cap 30 can also be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this embodiment of the present application does not impose any particular limitations on this. In some embodiments, an insulating member may be provided inside the end cap 30 to isolate the electrical connection portion 1112c in the housing 20 from the end cap 30 to reduce the risk of short circuit. For example, the insulating member may be made of plastic, rubber, or the like.

[0114] The housing 20 is a component that cooperates with the end cap 30 to form an internal environment for the battery cell 100. This internal environment can be used to accommodate the electrode assembly 10, electrolyte, and other components. The housing 20 and end cap 30 can be separate components. An opening can be provided in the housing 20, and the end cap 30 is placed over the opening to form the internal environment of the battery cell 100. Alternatively, the end cap 30 and housing 20 can be integrated. Specifically, the end cap 30 and housing 20 can form a common connection surface before other components are inserted into the housing. When the interior of the housing 20 needs to be enclosed, the end cap 30 is placed over the housing 20. The housing 20 can have a variety of shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. Specifically, the shape of the housing 20 can be determined based on the specific shape and size of the electrode assembly 10. The housing 20 can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this embodiment of the present application does not impose any particular limitations on this.

[0115] The electrode assembly 10 is a component in the battery cell 100 where electrochemical reactions occur. One or more electrode assemblies 10 may be contained in the housing 20. The electrode assembly 10 is mainly formed by winding or stacking a positive electrode sheet 114 and a negative electrode sheet 115, and a separator 12 is usually provided between the positive electrode sheet 114 and the negative electrode sheet 115. The portions of the positive electrode sheet 114 and the negative electrode sheet 115 with active materials constitute the main body of the electrode assembly 10, and the portions of the positive electrode sheet 114 and the negative electrode sheet 115 without active materials each constitute a tab. The positive electrode tab and the negative electrode tab may be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery device 1000, the positive electrode active material and the negative electrode active material react with the electrolyte, and the tabs are connected to the electrode terminals 40 to form a current loop.

[0116] First, reference Figures 4 to 7 The present embodiment provides a battery cell 100, including a pole piece 11, which includes a current collector 111 and an insulating layer 112. The current collector 111 includes two end surfaces 1111a located at opposite ends along the width direction of the current collector 111, and two side surfaces 1111b located at opposite sides along the thickness direction of the current collector 111. A protruding structure 1112 is formed on the end surface 1111a. The insulating layer 112 is disposed on the current collector 111, and the insulating layer 112 at least covers the end surface 1111a and the protruding structure 1112.

[0117] In the figure, the direction of the X-axis is the length direction of the electrode 11, which is also the length direction of the current collector 111; the direction of the Y-axis is the width direction of the electrode 11, which is also the width direction of the current collector 111; the direction of the Z-axis is the thickness direction of the electrode 11, which is also the thickness direction of the current collector 111.

[0118] The current collector 111 refers to the structure in the electrode 11 that is mainly used to support the flow of current. The main function of the current collector 111 is to provide an ion conductor in the electrochemical reaction to support the flow of current and separate the chemical reaction between the positive and negative electrodes so that the electron flow flows in the external circuit, thereby generating electrical energy. For example, in a lithium-ion battery, the current collector 111 can be a structural member of copper foil, aluminum foil or other materials.

[0119] The current collector 111 includes end faces 1111a and side faces 1111b. The end faces 1111a refer to the two opposite sides of the current collector 111 along its width direction Y. These are also the faces formed after the electrode 11 is cut, and burrs are typically formed on the end faces 1111a. The side faces 1111b refer to the two opposite sides of the current collector 111 along its thickness direction Z, and active material is typically formed on the side faces 1111b.

[0120] A protruding structure 1112 is also provided on the end face 1111a of the current collector 111. The protruding structure 1112 refers to the structure formed on the current collector 111 during the die-cutting process of the pole piece 11. The die-cutting of the pole piece 11 refers to the technology of cutting and forming the pole piece 11 using a mold. The shape and size of the pole piece 11 after die-cutting can meet the requirements; the protruding structure 1112 is a structure formed between the current collector 111 and the mold through extrusion, friction, cutting and other actions.

[0121] The protruding structure 1112 is formed on the end surface 1111a, and the protruding structure 1112 can be formed on the end surface 1111a by adjusting the die-cutting direction, angle, etc. of the mold; the protruding structure 1112 is a structure extending outward from the end surface 1111a and protruding from the collector 111 (for example, it can be a burr), and the protruding structure 1112 can be a regular shape or an irregular shape. The protruding structure 1112 can be in the shape of a spike, a semicircle, a wave or other shapes; the protruding structure 1112 can include one or more parts protruding from the end surface 1111a; according to the formation process of the protruding structure 1112, the material of the protruding structure 1112 is the same as the material of the collector 111.

[0122] The insulating layer 112 refers to a layered structure in the electrode 11 that is mainly used to protect the end face 1111a of the electrode 11; the insulating layer 112 covers the end face 1111a of the current collector 111. The insulating layer 112 can cover only one end face 1111a, or can be divided into two or more parts and cover two end faces 1111a respectively. The insulating layer 112 can cover only the end face 1111a, or can cover the end face 1111a and part of the adjacent side face 1111b; depending on the material of the insulating layer 112, the insulating layer 112 can be connected to the end face 1111a and / or the side face 1111b by bonding, welding or other means; the insulating layer 112 can also be a U-shaped, L-shaped or other shaped structure.

[0123] The insulating layer 112 covers the corresponding end surface 1111 a and can also cover the protruding structure 1112 on the corresponding end surface 1111 a so as to wrap the protruding structure 1112 inside the insulating layer 112 .

[0124] Because the protruding structure 1112 is usually a small structure, it is easily affected by the external environment (such as the shaking of the battery cell 100, the stirring of the electrolyte, etc.) and swings and deforms, and it is easy to pierce the adjacent diaphragm 12 and overlap on another adjacent pole piece 11 during the swinging deformation process, thereby causing a short circuit between the two adjacent pole pieces 11.

[0125] Under the cover of the insulating layer 112, the insulating layer 112 can separate the protruding structure 1112 from the external environment, and the protruding structure 1112 is not easy to pierce the insulating layer 112, so that the protruding structure 1112 is not easy to overlap with other adjacent pole pieces 11, and the protruding structure 1112 is not easily affected by the external environment; at the same time, the insulating layer 112 can also fix the position of the protruding structure 1112, so that the protruding structure 1112 is not easy to swing and deform, thereby further reducing the risk of the protruding structure piercing the insulating layer 112 and the diaphragm 12.

[0126] In this embodiment, a protruding structure 1112 is formed on the end face 1111a of the current collector 111. The protruding structure 1112 can easily pierce the diaphragm 12 adjacent to the pole piece 11 and cause a short circuit between the two adjacent pole pieces 11, thereby causing a short circuit in the battery cell 100. Accordingly, an insulating layer 112 is provided, and the protruding structure 1112 is covered by the insulating layer 112. The protruding structure 1112 is wrapped by the insulating layer 112 and the position of the protruding structure 1112 is fixed to reduce the risk of the protruding structure 1112 piercing the adjacent diaphragm 12, thereby reducing the risk of short circuit between adjacent pole pieces 11 and improving the safety and stability of the battery cell 100.

[0127] refer to Figure 5 、 Figure 9 、 Figure 10In some embodiments, the insulating layer 112 wraps the protruding structure 1112 .

[0128] The insulating layer 112 wraps the protruding structure 1112, that is, at least a portion of the insulating layer 112 can surround the protruding structure 1112 and wrap the protruding structure 1112 in the insulating layer 112. At this time, the protruding structure 1112 is fixed by the insulating layer 112, and the protruding structure 1112 is not easy to swing in the direction of the diaphragm 12 and pierce the diaphragm 12, thereby reducing the risk of the protruding structure 1112 piercing the diaphragm 12.

[0129] When the insulating layer 112 wraps the protruding structure 1112 , the protruding structure 1112 may not be deformed. In this case, the insulating layer 112 can also fix the protruding structure 1112 .

[0130] For example, the thickness of the insulating layer 112 can be made greater than the length of the protruding structure 1112, where the length of the protruding structure 1112 refers to the length thereof extending outside the current collector 111. In this case, the insulating layer 112 can wrap the protruding structure 1112, and the protruding structure 1112 is difficult to pierce the insulating layer 112.

[0131] When the insulating layer 112 wraps the protruding structure 1112, the protruding structure 1112 may also be deformed. The insulating layer 112 may press the protruding structure 1112 on the corresponding end face 1111a. The insulating layer 112 may also be folded to clamp the protruding structure 1112 and thereby change the extension direction of the protruding structure 1112. At this time, the insulating layer 112 can change the extension direction of the protruding structure 1112 to fix the protruding structure 1112 and make it difficult for the protruding structure 1112 to swing in the direction of the diaphragm 12, thereby reducing the risk of the protruding structure 1112 piercing the diaphragm 12.

[0132] For example, the insulating layer 112 can be folded and set on the end face 1111a, and the protruding structure 1112 can be clamped by the folded insulating layer 112. At this time, the folded insulating layer 112 can guide the extension direction of the protruding structure 1112, and at this time, it is difficult for the protruding structure 1112 to swing in the direction of the diaphragm 12; for example, the insulating layer 112 can also bend the protruding structure 1112 in the direction of the corresponding end face 1111a to press or fix the protruding structure 1112 on the corresponding end face 1111a.

[0133] In the technical solution of this embodiment, the insulating layer 112 wraps the protruding structure 1112, so that the protruding structure 1112 is not easy to pierce the insulating layer 112. At the same time, the insulating layer 112 wrapping the protruding structure 1112 can also play a role in fixing the protruding structure 1112, so that the protruding structure 1112 is not easy to swing relative to the current collector 111 and pierce the diaphragm 12.

[0134] refer to Figures 4 to 6 、 Figure 9 In some embodiments, the thickness of the insulating layer 112 ranges from 9 μm (micrometers) to 30 μm.

[0135] The thickness of the insulating layer 112 reflects the strength of the insulating layer 112. The thicker the insulating layer 112 is, the greater the resistance of the protruding structure 1112 to piercing the insulating layer 112 is, and the better the restraining effect of the insulating layer 112 on the protruding structure 1112 is; Figure 5 When part of the insulating layer 112 is connected to the side 1111b, the thickness of the insulating layer 112 can be the size of the part of the insulating layer 112 connected to the side 1111b in the thickness direction Z of the current collector 111, that is, the size shown by W in the figure.

[0136] Since the setting of the insulating layer 112 will occupy the internal space of the shell 20, and the space occupied by the insulating layer 112 is positively correlated with the thickness of the insulating layer 112, the thickness of the insulating layer 112 is less than or equal to 30μm; under the premise that the insulating layer 112 can cover the protruding structure 1112 and the protruding structure 1112 is not easy to pierce the insulating layer 112, the thickness of the insulating layer 112 should be smaller to reduce the negative impact of the insulating layer 112 on the energy density of the battery cell 100.

[0137] The thickness of the insulating layer 112 ranges from 9 μm to 30 μm. When the thickness of the insulating layer 112 is uniform or approximately uniform everywhere, the thickness of the insulating layer 112 refers to the thickness dimension of the insulating layer 112 at any part, and the dimension range is 9 μm to 30 μm. When the thickness of the insulating layer 112 is uneven, the thickness of the insulating layer 112 at the minimum thickness should be greater than or equal to 9 μm, and the thickness of the insulating layer 112 at the maximum thickness should be less than or equal to 30 μm.

[0138] The thickness of the insulating layer 112 ranges from 9 μm to 30 μm. For example, the thickness of the insulating layer 112 may be 9 μm, or may be 13 μm, 17 μm, 21 μm, 25 μm, 30 μm, or other values.

[0139] For example, the thickness of the insulating layer 112 is 9 μm. At this time, the insulating layer 112 can cover the protruding structure 1112 and has a certain strength, so that the protruding structure 1112 is not easy to pierce the insulating layer 112 and extend outside the insulating layer 112; at the same time, this setting can also reduce the space occupied by the insulating layer 112 and reduce the negative impact of the insulating layer 112 on the energy density of the battery cell 100.

[0140] For example, the thickness of the insulating layer 112 is 19.5 μm. At this time, the insulating layer 112 can not only well cover the protruding structure 1112, but also has a high strength, so that the protruding structure 1112 is difficult to pierce the insulating layer 112 and extend outside the insulating layer 112; the insulating layer 112 can also reduce the negative impact on the energy density of the battery cell 100.

[0141] For example, the thickness of the insulating layer 112 is 30 μm. In this case, the insulating layer 112 can better cover the protruding structure 1112 and has higher strength, so that the protruding structure 1112 is difficult to pierce the insulating layer 112 and extend outside the insulating layer 112, thereby improving the stability and safety of the battery cell 100.

[0142] This embodiment provides a thickness range for the insulating layer 112, such that the thickness of the insulating layer 112 is greater than or equal to 9 μm. After the insulating layer 112 covers the protruding structure 1112, the insulating layer 112 in this thickness range can better cover the protruding structure 1112 and has a certain strength, so that the protruding structure 1112 is difficult to pierce the insulating layer 112, thereby reducing the risk of the protruding structure 1112 piercing the adjacent diaphragm 12, reducing the risk of short circuiting of adjacent pole pieces 11, and improving the safety and stability of the battery cell 100; the thickness of the insulating layer 112 is less than or equal to 30 μm. Under the premise that the protruding structure 1112 is difficult to pierce the insulating layer 112, this setting can limit the thickness of the insulating layer 112 so that the thickness of the insulating layer 112 is not too large, thereby reducing the negative impact of the insulating layer 112 on the energy density of the battery cell 100.

[0143] In some embodiments, the insulating layer 112 has a puncture strength greater than or equal to 300 gf (gram force).

[0144] The puncture strength of the insulating layer 112 refers to the bearing capacity or ability of the insulating layer 112 to resist puncture damage under the action of a needle. The puncture strength of the insulating layer 112 reflects the ability of the insulating layer 112 to resist puncture by the protruding structure 1112, and also reflects the protection ability of the insulating layer 112 to the current collector 111; the puncture strength of the insulating layer 112 is greater than or equal to 300gf. For example, the puncture strength can be 300gf, 500gf, 800gf, 1000gf or other values.

[0145] When the thickness of the insulating layer 112 is equal to 9 μm, the thickness of the insulating layer 112 is the smallest. At this time, the puncture strength of the insulating layer 112 should be greater than or equal to 300 gf so that the protruding structure 1112 is not easy to pierce the insulating layer 112 .

[0146] For example, the puncture strength of the insulating layer 112 can be 300gf. At this time, the protruding structure 1112 is not easy to pierce the insulating layer 112, so that the insulating layer 112 can better reduce the risk of the protruding structure 1112 piercing the diaphragm 12 and causing the pole piece 11 to short-circuit; at the same time, this setting does not require the material of the insulating layer 112 to be too high, thereby reducing the processing cost and difficulty of the insulating layer 112.

[0147] The puncture strength of the insulating layer 112 can be tested using a steel needle on a puncture tester, and the force exerted when the steel needle punctures the insulating layer 112 at a certain speed can be recorded.

[0148] For example, the insulating layer 112 is made of insulating tape with a thickness of 13 μm and a length and width of 50 mm; a steel needle with a diameter of 1 mm is used to perform a test on a puncture tester, and the force when the insulating tape is punctured at a speed of 50 mm / min is recorded; when the base material layer 1121d of the insulating tape is polypropylene with a thickness of 10 μm and the adhesive layer 1121e is polyacrylate with a thickness of 3 μm, ten insulating tapes of the same specification are subjected to a puncture test, and the average puncture strength of the insulating tape is 425.31 gf.

[0149] This embodiment provides some puncture strength ranges for the insulating layer 112 , so that burrs are less likely to pierce the insulating layer 112 , thereby enabling the insulating layer 112 to better reduce the risk of short circuits between the burrs and adjacent pole pieces 11 .

[0150] refer to Figure 6 、 Figure 7 In some embodiments, the protruding structure 1112 includes at least two first protruding portions 1112a spaced apart along the length direction of the current collector 111, and the first protruding portions 1112a are formed on the end surface 1111a; the insulating layer 112 covers the first protruding portions 1112a.

[0151] The first protrusion 1112a refers to a structure in the protruding structure 1112; the shape of the first protrusion 1112a can be regular or irregular, and the shape of the first protrusion 1112a can be spike-shaped, semicircular, wavy or other shapes; because the first protrusion 1112a is a structure formed between the current collector 111 and the mold through extrusion, friction, cutting and other actions, the shape of the first protrusion 1112a is usually irregular.

[0152] The number of the first protrusions 1112a can be two, or three or more; multiple first protrusions 1112a are arranged at intervals along the length direction of the current collector 111, and there is a gap between two adjacent first protrusions 1112a. Since the first protrusions 1112a are structures formed between the current collector 111 and the mold through extrusion, friction, cutting, etc., the interval between the first protrusions 1112a is positively correlated with the movement cycle of the mold.

[0153] Since the first protrusions 1112 a are spaced apart from each other, the first protrusions 1112 a are single independent structures in the protrusion structure 1112 , and the first protrusions 1112 a are independent of each other and are not connected.

[0154] The first protrusion 1112a is formed on the end surface 1111a, and the first protrusion 1112a can be formed on the end surface 1111a by adjusting the die-cutting direction, angle, etc. of the mold; at this time, the position of the first protrusion 1112a is relatively fixed to facilitate the setting of the insulating layer 112 and covering each first protrusion 1112a.

[0155] The insulating layer 112 covers the first protrusion 1112a, so that the first protrusion 1112a is not easy to pierce the insulating layer 112, thereby making it difficult for the first protrusion 1112a to pierce the adjacent diaphragm 12 and overlap with the adjacent other pole piece 11. The insulating layer 112 can press the first protrusion 1112a on the end surface 1111a to fix the first protrusion 1112a and reduce the risk of the first protrusion 1112a piercing the insulating layer 112; the insulating layer 112 can also be folded at the end surface 1111a and clamp and fix the first protrusion 1112a at the fold to guide the extension direction of the first protrusion 1112a, so that the first protrusion 1112a is not easy to bend in the direction of the adjacent diaphragm 12, thereby reducing the risk of the first protrusion 1112a piercing The risk of the adjacent diaphragm 12; the insulating layer 112 can also completely wrap the first protrusion 1112a to fix the first protrusion 1112a. Under the wrapping of the insulating layer 112, the first protrusion 1112a is difficult to pierce the diaphragm 12 even if it bends in the direction of the diaphragm 12, thereby reducing the risk of the first protrusion 1112a piercing the diaphragm 12 and short-circuiting with the adjacent pole piece 11; it is understandable that the insulating layer 112 can also cover the first protrusion 1112a in other ways, not limited to the above-mentioned ways.

[0156] This embodiment provides some specific structures of the protruding structure 1112, so that the protruding structure 1112 includes first protruding portions 1112a arranged at intervals, and the insulating layer 112 can cover the first protruding portions 1112a, so that the insulating layer 112 can adapt to the structure of the first protruding portions 1112a.

[0157] refer to Figure 6 、 Figure 7 In some embodiments, the length of the first protrusion 1112a ranges from 40 μm to 200 μm.

[0158] The length of the first protrusion 1112a refers to the length of the first protrusion 1112a extending outside the current collector 111. The length of the first protrusion 1112a also represents the maximum thickness of the diaphragm 12 that the first protrusion 1112a can pierce, that is, when the maximum thickness of the diaphragm 12 is less than the length of the first protrusion 1112a, the first protrusion 1112a can pierce the diaphragm 12.

[0159] Example, reference Figure 7 When the first protrusion 1112a extends from the end surface 1111a along the width direction Y of the current collector 111 away from the current collector 111, the length of the first protrusion 1112a is the dimension of the first protrusion 1112a in the width direction Y of the current collector 111.

[0160] The length of the first protrusion 1112a ranges from 40μm to 200μm. For example, the length of the first protrusion 1112a can be 40μm, or 40μm, 60μm, 80μm, 100μm, 120μm, 140μm, 160μm, 180μm, 200μm or other values; the length of the first protrusion 1112a can also be adjusted and controlled by adjusting the mold, adjusting the cutting rate, etc., but due to the limitation of processing accuracy, the length of the first protrusion 1112a is difficult to be less than 40μm.

[0161] For example, the length of the first protrusion 1112a can be 40 μm. In this case, the length of the first protrusion 1112a is small, and accordingly, the thickness of the insulating layer 112 can also be small. On the premise that the insulating layer 112 can cover the first protrusion 1112a, this setting can better reduce the space occupied by the first protrusion 1112a and the insulating layer 112, and better reduce the negative impact of the insulating layer 112 on the energy density of the battery cell 100.

[0162] For example, the length of the first protrusion 1112a can be 120 μm. In this case, the length of the first protrusion 1112a is relatively large. Accordingly, the thickness of the insulating layer 112 can also be relatively thick, so that the insulating layer 112 can not only cover the first protrusion 1112a to reduce the risk of the first protrusion 1112a piercing the diaphragm 12, but also reduce the space occupied by the insulating layer 112 and reduce the negative impact of the insulating layer 112 on the energy density of the battery cell 100.

[0163] For example, the length of the first protrusion 1112a can be 200 μm. In this case, the length of the first protrusion 1112a is larger, and accordingly, the thickness of the insulating layer 112 can also be larger, so that the insulating layer 112 can better cover the first protrusion 1112a, thereby making it difficult for the first protrusion 1112a to pierce the diaphragm 12 and short-circuit with the adjacent pole piece 11.

[0164] This embodiment provides some size ranges of the first protrusions 1112a and enables the insulating layer 112 to adapt to the structure of the first protrusions 1112a, so that the insulating layer 112 can cover first protrusions 1112a of different sizes, thereby making it difficult for protrusion structures 1112 of different sizes to pierce the insulating layer 112.

[0165] refer to Figure 6 、 Figure 7 In some embodiments, in the length direction of the current collector 111 , the number of the first protrusions 1112 a within a size range of 1 mm is greater than or equal to 1; the thickness of the insulating layer 112 is in the range of 13 μm to 30 μm.

[0166] The number of first protrusions 1112a within a size range of 1 mm in the length direction X of the current collector 111 represents the density of the first protrusions 1112a. The number of first protrusions 1112a within this size range is greater than or equal to 1, that is, within the size range of 1 mm, the number of first protrusions 1112a can be one, or two or more; the greater the number of first protrusions 1112a within this size range, the higher the risk that one or more of the multiple first protrusions 1112a pierce the insulating layer 112 and the diaphragm 12.

[0167] Accordingly, the thickness of the insulating layer 112 is in the range of 13 μm to 30 μm. Even if the thickness of the insulating layer 112 is relatively thick, the insulating layer 112 can have higher strength, so that the insulating layer 112 can better cover and fix the first protrusion 1112a, reducing the risk of the first protrusion 1112a piercing the insulating layer 112 and piercing the diaphragm 12.

[0168] The thickness of the insulating layer 112 may be 13 μm, or may be 16 μm, 19 μm, 22 μm, 25 μm, 27 μm, 30 μm, or other values.

[0169] For example, the thickness of the insulating layer 112 is 13 μm. Under the premise that the insulating layer 112 can cover and fix the first protrusion 1112 a , this configuration can reduce the space occupied by the insulating layer 112 and reduce the negative impact of the insulating layer 112 on the energy density of the battery cell 100 .

[0170] For example, the thickness of the insulating layer 112 is 21.5 μm. At this time, the insulating layer 112 can better cover and fix the first protrusion 1112a, so that the first protrusion 1112a is difficult to pierce the insulating layer 112 and extend outside the insulating layer 112; the insulating layer 112 can also reduce the negative impact on the energy density of the battery cell 100.

[0171] For example, the thickness of the insulating layer 112 is 30 μm. In this case, the insulating layer 112 can better cover and fix the protruding structure 1112 , so that the protruding structure 1112 is difficult to pierce the insulating layer 112 and extend outside the insulating layer 112 , thereby improving the stability and safety of the battery cell 100 .

[0172] This embodiment provides some arrangement structures of the first protrusions 1112a and corresponding specific thickness ranges of the insulating layer 112, so that the insulating layer 112 can better adapt to the size and arrangement structure of the first protrusions 1112a, thereby enabling the insulating layer 112 to better cover and fix the first protrusions 1112a, and making it difficult for the first protrusions 1112a to pierce the insulating layer 112.

[0173] refer to Figure 6 、 Figure 7 In some embodiments, the protruding structure 1112 further includes a plurality of second protruding portions 1112b spaced apart along the length direction of the current collector 111, and a connecting portion 1112c is provided between two adjacent second protruding portions 1112b, and the connecting portion 1112c and the second protruding portion 1112b are both formed on the end surface 1111a; the length of the connecting portion 1112c is smaller than the length of the second protruding portion 1112b; the insulating layer 112 covers the second protruding portions 1112b and the connecting portion 1112c.

[0174] The second protrusion 1112b refers to a structure in the protruding structure 1112; the shape of the second protrusion 1112b can be regular or irregular, and the shape of the second protrusion 1112b can be spike-shaped, semicircular, wavy or other shapes; because the second protrusion 1112b is a structure formed between the collector 111 and the mold through extrusion, friction, cutting and other actions, the shape of the second protrusion 1112b is usually irregular; the number of second protrusions 1112b can be two or three or more; multiple second protrusions 1112b are arranged at intervals along the length direction of the collector 111, and there is a gap between two adjacent second protrusions 1112b.

[0175] The connecting portion 1112c refers to a structure in the protruding structure 1112. Since there is a gap between two adjacent second protruding portions 1112b, the connecting portion 1112c is formed between two adjacent second protruding portions 1112b and is connected to two adjacent second protruding portions 1112b, so that each second protruding portion 1112b and each connecting portion 1112c can form a continuous structure; since the second protruding portion 1112b is a structure formed between the current collector 111 and the mold through extrusion, friction, cutting, etc., the number, spacing, arrangement, etc. of the second protruding portions 1112b in a single continuous structure are positively correlated with the movement cycle of the mold.

[0176] The protruding structure 1112 may include only one continuous structure, or may include two or more continuous structures. Since the continuous structure is formed by extrusion, friction, cutting, etc. between the current collector 111 and the mold, the number, spacing, arrangement, etc. of the continuous structure are positively correlated with the movement cycle of the mold.

[0177] The second protrusion 1112b and the connecting portion 1112c are both formed on the end surface 1111a. The second protrusion 1112b and the connecting portion 1112c can be formed on the end surface 1111a by adjusting the die-cutting direction and angle of the mold; at this time, the positions of the second protrusion 1112b and the connecting portion 1112c are relatively fixed, so as to facilitate the setting of the insulating layer 112 and cover each second protrusion 1112b and each connecting portion 1112c.

[0178] The length of the connecting portion 1112c refers to the length of the connecting portion 1112c extending outside the current collector 111; Figure 7 When the connecting portion 1112c extends from the end surface 1111a along the width direction Y of the current collector 111 away from the current collector 111, the length of the connecting portion 1112c also refers to the size of the connecting portion 1112c in the width direction Y of the current collector 111.

[0179] Similar to the connecting portion 1112c, the length of the second protrusion 1112b refers to the length of the second protrusion 1112b extending outside the current collector 111; Figure 7 When the second protrusion 1112b extends from the end surface 1111a away from the current collector 111 along the width direction Y of the current collector 111, the length of the second protrusion 1112b also refers to the size of the second protrusion 1112b in the width direction Y of the current collector 111.

[0180] The length of the connecting portion 1112c is smaller than the length of the second protrusion 1112b, that is, in the continuous structure formed by the second protrusion 1112b and the connecting portion 1112c, the second protrusion 1112b is more likely to pierce the adjacent diaphragm 12 and short-circuit with the other adjacent pole piece 11; accordingly, the setting of the insulating layer 112 should be set according to the size of the second protrusion 1112b. When the insulating layer 112 can reduce the risk of the second protrusion 1112b piercing the diaphragm 12, the connecting portion 1112c is more difficult to pierce the diaphragm 12.

[0181] The insulating layer 112 covers the second protrusion 1112b, so that the second protrusion 1112b is not easy to pierce the insulating layer 112, thereby making it difficult for the second protrusion 1112b to pierce the adjacent diaphragm 12 and overlap with another adjacent pole piece 11; because the length of the connecting portion 1112c is smaller than the length of the second protrusion 1112b, it is even more difficult for the connecting portion 1112c to pierce the adjacent diaphragm 12.

[0182] The insulating layer 112 can press the second protrusion 1112b and the connecting portion 1112c on the end surface 1111a to fix the second protrusion 1112b and the connecting portion 1112c and reduce the risk of the second protrusion 1112b piercing the insulating layer 112; the insulating layer 112 can also be folded at the end surface 1111a, and the second protrusion 1112b and the connecting portion 1112c are clamped and fixed at the folded portion to guide the extension direction of the second protrusion 1112b and the connecting portion 1112c, so that the second protrusion 1112b and the connecting portion 1112c are not easy to bend in the direction of the adjacent diaphragm 12, thereby reducing the risk of the second protrusion 1112b piercing the insulating layer 112. The risk of the second protrusion 1112b piercing the adjacent diaphragm 12 is reduced; the insulating layer 112 can also completely wrap the second protrusion 1112b and the connecting portion 1112c to fix the second protrusion 1112b and the connecting portion 1112c. Under the wrapping of the insulating layer 112, the second protrusion 1112b is difficult to pierce the diaphragm 12 even if it is bent in the direction of the diaphragm 12, thereby reducing the risk of the second protrusion 1112b piercing the diaphragm 12 and short-circuiting with the adjacent other pole piece 11; it is understandable that the insulating layer 112 can also cover the second protrusion 1112b in other ways, not limited to the above-mentioned ways.

[0183] This embodiment provides other specific structures of the protruding structure 1112, so that the protruding structure 1112 includes second protruding portions 1112b arranged at intervals, and a connecting portion 1112c is provided between adjacent second protruding portions 1112b; the insulating layer 112 is able to cover the second protruding portions 1112b, so that the insulating layer 112 can adapt to the structure of the second protruding portions 1112b.

[0184] refer to Figure 6 、 Figure 7In some embodiments, the length of the second protrusion 1112b ranges from 15 μm to 40 μm.

[0185] The length of the second protrusion 1112b refers to the length of the second protrusion 1112b extending outside the current collector 111; that is, when the maximum thickness of the separator 12 is less than the length of the second protrusion 1112b, the second protrusion 1112b can pierce the separator 12.

[0186] Example, reference Figure 7 When the second protrusion 1112b extends from the end surface 1111a along the width direction of the current collector 111 away from the current collector 111, the length of the second protrusion 1112b is the dimension Y of the second protrusion 1112b in the width direction of the current collector 111.

[0187] The length range of the second protrusion 1112b is 15μm to 40μm. For example, the length of the second protrusion 1112b can be 15μm, or it can be 20μm, 25μm, 30μm, 35μm, 40μm or other values; the length of the second protrusion 1112b can also be adjusted and controlled by adjusting the mold, adjusting the cutting rate, etc., but due to the limitation of processing accuracy, the length of the second protrusion 1112b is difficult to be less than 15μm.

[0188] For example, the length of the second protrusion 1112b can be 15 μm. In this case, the length of the second protrusion 1112b is small, and accordingly, the thickness of the insulating layer 112 can also be small. On the premise that the insulating layer 112 can cover and fix the second protrusion 1112b, this setting can better reduce the space occupied by the second protrusion 1112b and the insulating layer 112, and better reduce the negative impact of the insulating layer 112 on the energy density of the battery cell 100.

[0189] For example, the length of the second protrusion 1112b can be 27.5 μm. In this case, the length of the second protrusion 1112b is relatively large. Accordingly, the thickness of the insulating layer 112 can also be relatively thick, so that the insulating layer 112 can not only cover and fix the second protrusion 1112b to reduce the risk of the second protrusion 1112b piercing the diaphragm 12, but also reduce the space occupied by the insulating layer 112 and reduce the negative impact of the insulating layer 112 on the energy density of the battery cell 100.

[0190] For example, the length of the second protrusion 1112b can be 40 μm. In this case, the length of the second protrusion 1112b is larger, and accordingly, the thickness of the insulating layer 112 can also be larger, so that the insulating layer 112 can better cover and fix the second protrusion 1112b, thereby making it difficult for the second protrusion 1112b to pierce the diaphragm 12 and short-circuit with the adjacent pole piece 11.

[0191] It is understood that, depending on the processing technology, the current collector 111 may only have the first protrusion 1112a or the second protrusion 1112b, or the current collector 111 may also have both the first protrusion 1112a and the second protrusion 1112b. In the case where the first protrusion 1112a and the second protrusion 1112b are both present on the current collector 111, the length of the first protrusion 1112a is greater than or equal to the length of the second protrusion 1112b, depending on the length range of the first protrusion 1112a and the length range of the second protrusion 1112b. In this case, if the insulating layer 112 can cover and fix the first protrusion 1112a to reduce the risk of it piercing the diaphragm 12, the insulating layer 112 can also cover and fix the second protrusion 1112b to reduce the risk of it piercing the diaphragm 12.

[0192] This embodiment provides some size ranges of the second protrusions 1112b and enables the insulating layer 112 to adapt to the structure of the second protrusions 1112b, so that the insulating layer 112 can cover second protrusions 1112b of different sizes, thereby making it difficult for protrusion structures 1112 of different sizes to pierce the insulating layer 112.

[0193] refer to Figure 6 、 Figure 7 In some embodiments, in the length direction of the current collector 111 , the number of the second protrusions 1112 b within a size range of 1 mm is in the range of 3 to 5; the thickness of the insulating layer 112 is in the range of 9 μm to 13 μm.

[0194] The number of second protrusions 1112b within a size range of 1 mm in the length direction X of the current collector 111 represents the density of the second protrusions 1112b. The number of second protrusions 1112b within this size range is 3 to 5, that is, within the size range of 1 mm, the number of second protrusions 1112b can be three, four or five; the greater the number of second protrusions 1112b within this size range, the higher the risk that one or more of the multiple second protrusions 1112b will pierce the insulating layer 112 and the diaphragm 12.

[0195] Because the length of the second protrusion 1112b is relatively short, when the number of the second protrusions 1112b within the size range of 1mm is in the range of 3 to 5, the thickness of the insulating layer 112 is in the range of 9μm to 13μm. This can not only enable the insulating layer 112 to better cover and fix the second protrusion 1112b, thereby reducing the risk of the second protrusion 1112b piercing the insulating layer 112 and piercing the diaphragm 12, but also reduce the space occupied by the insulating layer 112, and reduce the negative impact of the insulating layer 112 on the energy density of the battery cell 100.

[0196] The thickness of the insulating layer 112 may be 9 μm, or may be 10 μm, 11 μm, 12 μm, 13 μm, or other values.

[0197] For example, the thickness of the insulating layer 112 is 9 μm. Under the premise that the insulating layer 112 can cover and fix the second protrusion 1112 b , this configuration can reduce the space occupied by the insulating layer 112 and reduce the negative impact of the insulating layer 112 on the energy density of the battery cell 100 .

[0198] For example, the thickness of the insulating layer 112 is 11 μm. In this case, the insulating layer 112 can better cover and fix the second protrusion 1112 b so that the second protrusion 1112 b is difficult to pierce the insulating layer 112 and extend outside the insulating layer 112; the insulating layer 112 can also reduce the negative impact on the energy density of the battery cell 100.

[0199] For example, the thickness of the insulating layer 112 is 13 μm. In this case, the insulating layer 112 can better cover and fix the second protrusion 1112 b, so that the second protrusion 1112 b is difficult to pierce the insulating layer 112 and extend outside the insulating layer 112 , thereby improving the stability and safety of the battery cell 100 .

[0200] This embodiment provides some arrangement structures of the second protrusions 1112b and a specific thickness range of the corresponding insulating layer 112, so that the insulating layer 112 can better adapt to the size and arrangement structure of the second protrusions 1112b, thereby enabling the insulating layer 112 to better cover and fix the second protrusions 1112b, and making it difficult for the second protrusions 1112b to pierce the insulating layer 112.

[0201] refer to Figure 6 、 Figure 7 In some embodiments, in the length direction of the current collector 111 , the number of the second protrusions 1112 b within a size range of 1 mm is in a range of 5 to 15; the thickness of the insulating layer 112 is in a range of 13 μm to 30 μm.

[0202] The number of the second protrusions 1112b within the 1mm size range in the length direction X of the current collector 111 may also be in the range of 5 to 15, that is, within the 1mm size range, the number of the second protrusions 1112b may be five, or six, ten, fifteen or other numbers; the greater the number of the second protrusions 1112b within this size range, the higher the risk that one or more of the multiple second protrusions 1112b pierce the insulating layer 112 and the diaphragm 12.

[0203] When the number of the second protrusions 1112b within a size range of 1mm is in the range of 5 to 15, the number of the second protrusions 1112b is large, and the risk of the second protrusions 1112b piercing the insulating layer 112 and the diaphragm 12 is high; accordingly, the thickness of the insulating layer 112 is in the range of 13μm to 30μm, so that the insulating layer 112 can have higher strength, so that the insulating layer 112 can better cover and fix the second protrusions 1112b, so as to reduce the risk of the second protrusions 1112b piercing the insulating layer 112 and the diaphragm 12.

[0204] The thickness of the insulating layer 112 may be 13 μm, or may be 16 μm, 19 μm, 22 μm, 25 μm, 27 μm, 30 μm, or other values.

[0205] For example, the thickness of the insulating layer 112 is 13 μm. Under the premise that the insulating layer 112 can cover and fix the second protrusion 1112 b , this configuration can reduce the space occupied by the insulating layer 112 and reduce the negative impact of the insulating layer 112 on the energy density of the battery cell 100 .

[0206] For example, the thickness of the insulating layer 112 is 21.5 μm. At this time, the insulating layer 112 can better cover and fix the second protrusion 1112 b, so that the second protrusion 1112 b is difficult to pierce the insulating layer 112 and extend outside the insulating layer 112; the insulating layer 112 can also reduce the negative impact on the energy density of the battery cell 100.

[0207] For example, the thickness of the insulating layer 112 is 30 μm. In this case, the insulating layer 112 can better cover and fix the second protrusion 1112 b, so that the second protrusion 1112 b is difficult to pierce the insulating layer 112 and extend outside the insulating layer 112 , thereby improving the stability and safety of the battery cell 100 .

[0208] This embodiment provides other arrangement structures of the second protrusions 1112b and corresponding specific thickness ranges of the insulating layer 112, so that the insulating layer 112 can better adapt to the size and arrangement structure of the second protrusions 1112b, thereby enabling the insulating layer 112 to better cover the second protrusions 1112b and making it difficult for the second protrusions 1112b to pierce the insulating layer 112.

[0209] refer to Figure 6 、 Figures 8 to 10In some embodiments, the insulating layer 112 includes two sub-insulating layers 1121 corresponding to the two side surfaces 1111b, the sub-insulating layer 1121 includes a first portion 1121a and a second portion 1121b connected to the first portion 1121a, and the second portion 1121b is connected to the side surface 1111b; at least a portion of the first portion 1121a is connected to the first portion 1121a of another adjacent sub-insulating layer 1121, and the two first portions 1121a clamp the protruding structure 1112 to guide the protruding structure 1112 to extend along the width direction of the current collector 111.

[0210] The sub-insulating layer 1121 refers to a part of the insulating layer 112. There are two sub-insulating layers 1121, and the two sub-insulating layers 1121 can be spliced ​​together to form the insulating layer 112; the two sub-insulating layers 1121 can be arranged on opposite sides of the current collector 111 and converge and connect at the end face 1111a of the current collector 111, so that the insulating layer 112 can cover both the end face 1111a and a part of the side face 1111b.

[0211] Sub-insulating layer 1121 includes a first portion 1121a and a second portion 1121b. Second portion 1121b is a portion of sub-insulating layer 1121 and is connected to side surface 1111b to secure sub-insulating layer 1121. Depending on the material of sub-insulating layer 1121, second portion 1121b can be bonded to side surface 1111b or connected to side surface 1111b by curing. First portion 1121a is also a portion of sub-insulating layer 1121 and is connected to second portion 1121b. First portion 1121a and second portion 1121b can be integrally formed, or connected to second portion 1121b by bonding, curing, or other methods.

[0212] Because the second part 1121b is connected to the side surface 1111b, the first part 1121a can extend outside the current collector 111. Because the insulating layer 112 is arranged on the side of the current collector 111 having the pole ear portion 1113, at least part of the first part 1121a can be connected to the first part 1121a of another adjacent sub-insulating layer 1121. At this time, the first part 1121a can cooperate with the other first part 1121a connected to cover the corresponding end face 1111a.

[0213] The first part 1121a can extend beyond the current collector 111, and parts of the two first parts 1121a can be connected to each other and clamp the protruding structure 1112 between the two first parts 1121a. At this time, the two first parts 1121a can play a role in correcting the direction of the protruding structure 1112, that is, under the action of the two first parts 1121a, the protruding structure 1112 can extend in a direction parallel or approximately parallel to the width direction Y of the current collector 111, so that the protruding structure 1112 is less likely to pierce the insulating layer 112, and also makes it more difficult for the protruding structure 1112 to pierce the diaphragm 12 adjacent to the pole piece 11, so as to better reduce the risk of the protruding structure 1112 piercing the diaphragm 12 and short-circuiting with the other pole piece 11.

[0214] This embodiment provides some specific structures of the insulating layer 112, so that the insulating layer 112 is formed by two sub-insulating layers 1121 connected to each other; the sub-insulating layer 1121 includes a first part 1121a and a second part 1121b, and the two first parts 1121a clamp the protruding structure 1112, so as to guide and limit the extension direction of the protruding structure 1112 through the two first parts 1121a, so that the protruding structure 1112 is not easy to bend to the sides and pierce the sub-insulating layer 1121 or the adjacent diaphragm 12.

[0215] refer to Figure 6 、 Figures 8 to 10 In some embodiments, the current collector 111 includes a current collector body 1111 and a pole ear portion 1113 connected to the current collector body 1111, the side surface 1111b and the end surface 1111a are both formed on the current collector body 1111, and the pole ear portion 1113 extends from either of the two end surfaces 1111a along the width direction of the current collector 111 toward a direction away from the current collector body 1111.

[0216] The current collector body 1111 refers to the partial structure in the current collector 111 used to carry active materials; the end face 1111a and the side face 1111b both refer to faces on the current collector body 1111, that is, the end face 1111a refers to the two faces located at opposite ends of the current collector body 1111 along the width direction Y of the current collector 111, and the side face 1111b refers to the two faces located at opposite sides of the current collector body 1111 along the thickness direction Z of the current collector 111.

[0217] The pole ear portion 1113 refers to the partial structure of the current collector 111 that extends outward from the current collector body 1111. The pole ear portion 1113 is used to connect the pole piece 11 with the circuit outside the electrode assembly 10; the pole ear portion 1113 can be integrally formed with the current collector body 1111, or it can be connected to the current collector body 1111 by gluing, welding, etc.; there can be one pole ear portion 1113, or there can be two or more pole ear portions 1113.

[0218] The tab portion 1113 extends from one of the two end surfaces 1111 a to the outside of the current collector body 1111 , and the tab portion 1113 extends along the width direction Y of the current collector 111 .

[0219] The pole ear portion 1113 is usually formed by a die-cutting process. At this time, the protruding structure 1112 is formed on the end surface 1111a connected to the pole ear portion 1113, and the insulating layer 112 also covers the end surface 1111a connected to the pole ear portion 1113; when the insulating layer 112 includes a first portion 1121a and a second portion 1121b, the first portion 1121a extends to extend beyond the current collector 111 along the width direction Y of the current collector 111. At this time, in addition to being able to cover the corresponding end surface 1111a, the first portion 1121a has a position on the corresponding end surface 1111a with the pole ear portion 1113, and the first portion 1121a can also cover at least part of the pole ear portion 1113. The part of the insulating layer 112 covering the end surface 1111a is connected to the corresponding adjacent other first portion 1121a, and the part of the first portion 1121a covering the pole ear portion 1113 is connected to the corresponding pole ear portion 1113.

[0220] refer to Figure 6 、 Figures 8 to 10 In some embodiments, in the width direction of the current collector 111 , the size of the first portion 1121 a ranges from 0.2 mm to 6 mm.

[0221] The dimension of the first portion 1121a in the width direction Y of the current collector 111 is the width dimension of the first portion 1121a. Figures 8 to 10 , the size shown in L1 in the figure is the size of the first portion 1121a in the width direction Y of the current collector 111; the size range of the first portion 1121a in the width direction Y of the current collector 111 is 0.2mm~6mm. For example, the size of the first portion 1121a in the width direction Y of the current collector 111 can be 0.2mm, 1mm, 1.8mm, 2.6mm, 2.9mm, 3.4mm, 4.2mm, 5.1mm, 6mm or other values.

[0222] Because the first portion 1121a is used to extend beyond the current collector 111 and cover the end face 1111a and the protruding structure 1112, the size of the first portion 1121a in the width direction Y of the current collector 111 is positively correlated with the size of the first portion 1121a covering the protruding structure 1112; the size of the first portion 1121a in the width direction Y of the current collector 111 should not be too small and should be at least greater than or equal to the maximum length of the protruding structure 1112, so that the first portion 1121a can cover the protruding structure 1112.

[0223] Since the first portion 1121a also covers part of the pole ear portion 1113, the size of the first portion 1121a should not be too large to reduce the negative impact of the first portion 1121a on the conductive performance of the pole ear portion 1113; at the same time, affected by the energy density of the battery cell 100, the size of the first portion 1121a should not be too large to reduce the negative impact of the first portion 1121a on the energy density of the battery cell 100.

[0224] For example, the size of the first part 1121a in the width direction Y of the current collector 111 can be 0.2 mm. On the premise that the first part 1121a can cover the protruding structure 1112, this arrangement can make the size of the first part 1121a smaller, so as to reduce the area covered by the first part 1121a on the pole ear part 1113 and reduce the space occupied by the first part 1121a, thereby reducing the negative impact of the first part 1121a on the conductive performance of the pole ear part 1113 and the energy density of the battery cell 100.

[0225] For example, the size of the first part 1121a in the width direction Y of the current collector 111 can be 3.1 mm. At this time, the first part 1121a can not only better cover the protruding structure 1112 to reduce the risk of the protruding structure 1112 piercing the adjacent diaphragm 12; it can also reduce the area and space occupied by the first part 1121a covering the pole ear part 1113, thereby reducing the negative impact of the first part 1121a on the conductive performance of the pole ear part 1113 and the energy density of the battery cell 100.

[0226] For example, the size of the first portion 1121 a in the width direction Y of the current collector 111 may be 6 mm. In this case, the first portion 1121 a can better cover the protruding structure 1112 to better reduce the risk of the protruding structure 1112 piercing the adjacent diaphragm 12 .

[0227] This embodiment provides some size ranges of the first part 1121a so that the first part 1121a can not only better cover the protruding structure 1112 to reduce the risk of the protruding structure 1112 piercing the insulating layer 112; it can also reduce the occupation of the internal space of the battery cell 100 by the first part 1121a, reducing the negative impact of the insulating layer 112 on the energy density of the battery cell 100; and it can reduce the area of ​​the pole ear part 1113 covered by the first part 1121a, reducing the negative impact of the insulating layer 112 on the conductive performance of the pole ear part 1113.

[0228] refer to Figure 6 、 Figures 8 to 10 In some embodiments, the electrode 11 further includes an active material layer 113 disposed on the side surface 1111 b , and the active material layer 113 covers at least a portion of the side surface 1111 b ; the sub-insulating layer 1121 is connected to the active material layer 113 .

[0229] The active material layer 113 refers to a layered structure formed on the side 1111b of the current collector 111 and used to participate in the electrochemical reaction. Depending on the polarity of the electrode 11, the material of the active material layer 113 may include lithium manganese oxide, lithium cobalt oxide, nickel cobalt lithium manganese oxide and other materials. The material of the active material layer 113 may also include natural graphite, artificial graphite and other materials.

[0230] The active material layer 113 may cover only a portion of the side surface 1111b, or may completely cover the entire adjacent side surface 1111b; because the area of ​​the active material layer 113 is positively correlated with the charge and discharge performance of the electrode 11, the active material layer 113 should cover the corresponding side surface 1111b as much as possible, that is, the active material layer 113 should cover most of the corresponding side surface 1111b or completely cover the corresponding side surface 1111b.

[0231] When the active material layer 113 covers most of or completely covers the corresponding side surface 1111b, the area of ​​the side surface 1111b not covered by the active material layer 113 is relatively small. At this time, connecting the sub-insulating layer 1121 to the active material layer 113 can improve the connection stability of the sub-insulating layer 1121.

[0232] In this embodiment, the sub-insulating layer 1121 is connected to the active material layer 113 so that the sub-insulating layer 1121 can be more stably connected to the pole piece 11 and cover the protruding structure 1112, thereby improving the stability of the insulating layer 112 and reducing the risk of structural failure caused by the insulating layer 112 falling off.

[0233] refer to Figure 6 、 Figures 8 to 10 In some embodiments, the active material layer 113 covers a portion of the side surface 1111b and forms a blank area 1111c on the side of the side surface 1111b close to the end surface 1111a, and the second portion 1121b covers at least a portion of the blank area 1111c.

[0234] The blank area 1111c refers to the area on the side surface 1111b that is not covered by the active material layer 113. The blank area 1111c is formed on the side surface 1111b and is located on the side of the side surface 1111b close to the end surface 1111a. Figure 9 The area corresponding to the size shown by L4 in the figure is the blank area 1111c.

[0235] The second portion 1121b covers at least part of the blank area 1111c, that is, the second portion 1121b can completely cover the blank area 1111c, or can only cover part of the blank area 1111c; for example, the second portion 1121b completely covers the blank area 1111c, and at this time, the end of the second portion 1121b away from the first portion 1121a contacts the active material layer 113.

[0236] The second portion 1121b covering the blank area 1111c can reduce the area of ​​direct contact between the current collector 111 and the electrolyte, thereby reducing damage to the current collector 111 by the electrolyte and reducing the occurrence of short circuits in the battery cell 100.

[0237] In this embodiment, the second portion 1121b can cover at least a portion of the blank area 1111c to protect the current collector 111. At the same time, it can also reduce the area of ​​the current collector 111 exposed to the outside, thereby reducing the occurrence of short circuits and the like, and improving the safety performance of the battery cell 100.

[0238] refer to Figure 6 、 Figures 8 to 10 In some embodiments, the size of the blank area 1111 c in the width direction of the current collector 111 is less than or equal to 5 mm.

[0239] The size of the blank area 1111c in the width direction Y of the current collector 111 is the width of the blank area 1111c, and the size of the blank area 1111c in the width direction Y of the current collector 111 is positively correlated with the area of ​​the blank area 1111c; the size of the blank area 1111c in the width direction Y of the current collector 111 is less than or equal to 5mm. For example, the size can be 5mm, 4.5mm, 4mm, 3.5mm, 3mm, 2.5mm, 2mm, 1.5mm, 1mm, 0.5mm, 0mm or other values.

[0240] It can be understood that when the size of the blank area 1111 c in the width direction Y of the current collector 111 is 0, the active material layer 113 completely covers the corresponding side surface 1111 b, and the blank area 1111 c does not exist.

[0241] The area of ​​the blank area 1111c is negatively correlated with the charge and discharge performance of the electrode 11, that is, the size of the blank area 1111c in the width direction Y of the current collector 111 is negatively correlated with the charge and discharge performance of the electrode 11. However, due to the influence of the processing technology, the blank area 1111c is not easy to completely eliminate, so the size of the blank area 1111c in the width direction Y of the current collector 111 should be as small as possible.

[0242] For example, the size of the blank area 1111c in the width direction Y of the current collector 111 is 5 mm. At this time, the charge and discharge performance of the electrode 11 can meet the minimum requirements; at the same time, the second part 1121b has a larger connection area, so that the second part 1121b can be more stably connected to the current collector 111.

[0243] For example, the size of the blank area 1111c in the width direction Y of the current collector 111 is 2.5 mm. Compared with the case where the size is 5 mm, the charge and discharge performance of the electrode 11 can be improved. At the same time, there is a certain space on the current collector 111 for the second part 1121b to be connected, so that the second part 1121b can be connected to the current collector 111.

[0244] For example, the size of the blank area 1111 c in the width direction Y of the current collector 111 is 0. In this case, the charge and discharge performance of the electrode 11 can better meet the requirements.

[0245] This embodiment provides a size range of some blank areas 1111c so that the sub-insulating layer 1121 can be more stably connected to the current collector 111 through the second part 1121b, while also reducing the negative impact of the blank areas 1111c on the coverage area of ​​the active material layer 113, thereby reducing the negative impact of the blank areas 1111c on the charge and discharge capabilities of the electrode 11.

[0246] refer to Figure 6 、 Figures 8 to 10 In some embodiments, the sub-insulating layer 1121 further includes a third portion 1121c connected to the second portion 1121b on the side opposite to the first portion 1121a, the second portion 1121b covers the blank area 1111c, and the third portion 1121c covers a portion of the active material layer 113.

[0247] The third part 1121c is a part of the sub-insulating layer 1121, and the third part 1121c is connected to the side of the second part 1121b away from the first part 1121a, that is, the first part 1121a, the second part 1121b, and the third part 1121c are arranged in sequence along the width direction Y of the current collector 111; the third part 1121c can be integrally formed with the second part 1121b, and the third part 1121c can also be connected to the second part 1121b by bonding, curing, etc.

[0248] The third portion 1121c is connected to the active material layer 113 and covers a portion of the active material layer 113. Since the third portion 1121c is connected to the second portion 1121b, the second portion 1121b can completely cover the blank area 1111c at this time, so as to better protect the main body 1131 and better improve the safety performance of the battery cell 100.

[0249] According to the structure of the third portion 1121 c , the third portion 1121 c may be connected to the active material layer 113 by bonding, or by curing or other methods.

[0250] If the sub-insulating layer 1121 does not cover the active material layer 113, then due to the influence of the processing technology, the second part 1121b of the sub-insulating layer 1121 is difficult to seal and contact the active material layer 113 without gaps, and the gap between the second part 1121b and the active material layer 113 can easily cause the main body 1131 to be exposed and cause a short circuit.

[0251] Accordingly, in this embodiment, the sub-insulating layer 1121 further includes a third portion 1121c , and the third portion 1121c covers a portion of the active material layer 113 , so that the second portion 1121b can completely cover the blank area 1111c , thereby further improving the safety performance of the battery cell 100 .

[0252] It can be understood that when the size of the blank area 1111c in the width direction Y of the current collector 111 is 0, that is, the active material layer 113 completely covers the corresponding side 1111b, the size of the second part 1121b in the width direction Y of the current collector 111 is also 0, that is, the second part 1121b does not exist, and the third part 1121c can be directly connected to the first part 1121a.

[0253] In this embodiment, the sub-insulating layer 1121 further includes a third portion 1121 c , and the third portion 1121 c covers a portion of the active material layer 113 , so that the second portion 1121 b can completely cover the blank area 1111 c , thereby further improving the safety performance of the battery cell 100 .

[0254] refer to Figure 6 、 Figures 8 to 10 In some embodiments, the active material layer 113 includes a main body 1131 and a transition portion 1132 connected to the main body 1131. The transition portion 1132 is provided on the side of the main body 1131 facing the end surface 1111a. The thickness of the transition portion 1132 gradually decreases along the direction from the main body 1131 to the end surface 1111a. The third portion 1121c covers at least a portion of the transition portion 1132.

[0255] The main body 1131 refers to a partial structure of the active material layer 113, and the main body 1131 is mainly used to exchange ions with the electrolyte to store and release electrical energy; the main body 1131 is connected to the corresponding side surface 1111b and covers most of the side surface 1111b; the transition portion 1132 refers to a partial structure of the active material layer 113, and the transition portion 1132 is located on the side of the main body 1131 toward the end surface 1111a along the width direction Y of the current collector 111, and the transition portion 1132 is mainly used to connect with the third portion 1121c to provide a fixed base for the third portion 1121c.

[0256] The thickness of the transition portion 1132 gradually decreases along the direction from the main body 1131 to the end face 1111a. Since the transition portion 1132 is provided on the side face 1111b, and the side face 1111b is a plane or a substantially plane, the surface of the transition portion 1132 facing away from the side face 1111b should be a curved surface or a sloped surface, so that the thickness of the transition portion 1132 gradually decreases from the main body 1131 to the end face 1111a. For example, the surface of the transition portion 1132 facing away from the side face 1111b is a sloped surface, and the sloped surface gradually approaches the side face 1111b in the direction from the main body 1131 to the end face 1111a.

[0257] The third part 1121c covers at least part of the transition part 1132, that is, the third part 1121c can completely cover the transition part 1132, or can only cover part of the transition part 1132; because the third part 1121c is connected to the active material layer 113, the third part 1121c is connected to the transition part 1132 to provide a fixed basis for the third part 1121c through the transition part 1132.

[0258] Because the thickness of the electrode 11 at the third part 1121c is the sum of the thickness of the current collector 111, the thickness of the two active material layers 113, and the thickness of the two third parts 1121c, in the thickness direction Z of the electrode 11, the third part 1121c is likely to be higher than the surface of the active material layer 113 away from the side surface 1111b, so that the thickness of the electrode 11 at the third part 1121c is relatively thick; the thick position may easily lead to an excessively large distance between the electrode 11 and the adjacent diaphragm 12, thereby having a negative impact on the energy density of the battery cell 100; in the process of winding and hot pressing the electrode 11, the stress on the electrode 11 at the third part 1121c is correspondingly greater, and the stress concentration is also more serious.

[0259] Accordingly, the active material layer 113 includes a main body 1131 and a transition portion 1132, the third portion 1121c covers the transition portion 1132, and the thickness of the transition portion 1132 gradually decreases; at this time, although the thickness of the electrode 11 at the third portion 1121c is the sum of the thickness of the current collector 111, the thickness of the two transition portions 1132 and the thickness of the two third portions 1121c, the thickness of the transition portion 1132 gradually decreases, thereby reducing the height of the third portion 1121c above the active material layer 113, and even enabling the third portion 1121c to be located below the surface of the active material layer 113 facing away from the side surface 1111b, so as to reduce the negative impact of the third portion 1121c on the energy density of the battery cell 100 and reduce the stress concentration at the third portion 1121c.

[0260] In order to reduce the safety risks caused by the exposure of the blank area 1111c, it is necessary to set the third part 1121c and make the third part 1121c cover part of the active material layer 113. Therefore, the transition part 1132 is set so that the third part 1121c can cover at least part of the transition part 1132, so that the second part 1121b can better cover the blank area 1111c, and the third part 1121c can reduce the negative impact on the thickness of the electrode 11, thereby reducing the negative impact of the third part 1121c on the energy density of the battery cell 100 and alleviating the stress concentration of the electrode 11 at the third part 1121c.

[0261] In this embodiment, the active material layer 113 includes a transition portion 1132 with a gradually decreasing thickness, and the third portion 1121c covers at least a portion of the transition portion 1132 to reduce the height of the third portion 1121c protruding from the active material layer 113, thereby reducing the negative impact of the insulating layer 112 on the energy density of the battery cell 100 and further alleviating the stress concentration of the electrode 11 at the insulating layer 112.

[0262] refer to Figure 6 、 Figures 8 to 10 In some embodiments, in the width direction of the current collector 111 , the size of the third portion 1121 c ranges from 0.1 mm to 1 mm.

[0263] The size of the third portion 1121c in the width direction Y of the current collector 111 is the width of the projection of the third portion 1121c on the side surface 1111b along the thickness direction Z of the current collector 111. Because the surface of the transition portion 1132 away from the side surface 1111b is not horizontal, the length of the third portion 1121c is not consistent with the size of the third portion 1121c in the width direction Y of the current collector 111.

[0264] refer to Figures 8 to 10 The size of the third portion 1121c in the width direction Y of the current collector 111 is the size shown by L3 in the figure, and the size range is 0.1mm to 1mm. For example, the size can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.55mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm or other values.

[0265] When there is a blank area 1111c on the side 1111b of the current collector 111, the sub-insulating layer 1121 can be connected to the current collector 111 through the second part 1121b. At this time, the third part 1121c is mainly used to enable the second part 1121b to better cover the blank area 1111c, so the size of the third part 1121c in the width direction Y of the current collector 111 should be shorter.

[0266] For example, the size of the third part 1121c in the width direction Y of the current collector 111 can be 0.1 mm. At this time, the negative impact of the third part 1121c on the charge and discharge performance of the active material layer 113 is small, and the charge and discharge performance of the pole piece 11 is better; at the same time, the width of the third part 1121c on the transition part 1132 is small, and the thickness of the pole piece 11 at the third part 1121c is also small, which can better reduce the negative impact on the energy density of the battery cell 100 and better alleviate the stress concentration of the pole piece 11 at the third part 1121c.

[0267] For example, the size of the third part 1121c in the width direction Y of the current collector 111 can be 0.55 mm. At this time, the sub-insulating layer 1121 can be more stably connected to the current collector 111 through the third part 1121c and cover the end face 1111a; at the same time, it can also reduce the negative impact of the third part 1121c on the charge and discharge performance of the active material layer 113, and can also reduce the negative impact on the energy density of the battery cell 100, and alleviate the stress concentration of the electrode 11 at the third part 1121c.

[0268] For example, the size of the third part 1121c in the width direction Y of the current collector 111 can be 1 mm. At this time, the sub-insulating layer 1121 can be more stably connected to the current collector 111 through the third part 1121c and cover the end face 1111a, so that the insulating layer 112 can better cover the end face 1111a and the protruding structure 1112, and can improve the stability of the insulating layer 112.

[0269] This embodiment provides some size ranges of the third part 1121c, so that the third part 1121c can be more stably connected to the transition part 1132 and not easily fall off, so that the second part 1121b can better cover the blank area 1111c, reducing the risk of short circuit and damage caused by the exposure of the blank area 1111c; at the same time, this setting can also make the third part 1121c less likely to protrude from the plane where the active material layer 113 deviates from the surface of the corresponding side 1111b, or can reduce the height of the third part 1121c protruding from the plane where the active material layer 113 deviates from the surface of the corresponding side 1111b, so as to reduce the stress concentration at the third part 1121c during the winding and hot pressing process, thereby reducing the possible damage to the electrode 11.

[0270] refer to Figure 6 、 Figure 8 、 Figure 12 In some embodiments, the sub-insulating layer 1121 includes a substrate layer 1121d and an adhesive layer 1121e disposed on the substrate layer 1121d , and the adhesive layer 1121e is disposed on a side of the substrate layer 1121d facing the current collector 111 .

[0271] The substrate layer 1121d refers to a layered structure in the sub-insulating layer 1121 that is mainly used to provide a fixed basis. The substrate layer 1121d can be used to provide a fixed basis for the adhesive layer 1121e, and can also protect the corresponding pole piece 11; according to the function of the substrate layer 1121d, the substrate layer 1121d should have a certain strength and a certain insulation ability. The material of the substrate layer 1121d may include plastic, rubber, ceramic, etc.

[0272] The adhesive layer 1121e refers to a layered structure in the sub-insulating layer 1121 that mainly plays a fixing role. The adhesive layer 1121e is arranged on the side of the substrate layer 1121d facing the current collector 111 to fix the substrate layer 1121d on the current collector 111; the material of the adhesive layer 1121e may include rubber, resin or other materials; the adhesive layer 1121e can be connected to the current collector 111 by photocuring, thermal curing or other curing methods.

[0273] When the sub-insulating layer 1121 is connected to the current collector 111, the adhesive bonding can cover the end face 1111a and the protruding structure 1112, thereby fixing the protruding structure 1112. The substrate layer 1121d can also make it difficult for the protruding structure 1112 to pierce the sub-insulating layer 1121, thereby reducing the risk of the protruding structure 1112 piercing the diaphragm 12. At the same time, the substrate layer 1121d can also protect the current collector 111 and reduce the damage that other structures may cause to the current collector 111.

[0274] The technical solution of this embodiment provides some structures of the sub-insulating layer 1121, so that the sub-insulating layer 1121 includes an adhesive layer 1121e and a substrate layer 1121d, so that the substrate layer 1121d can be connected to the collector 111 through the adhesive layer 1121e, and can cover the protruding structure 1112 through the adhesive layer 1121e, and make it difficult for the protruding structure 1112 to pierce the insulating layer 112 through the substrate layer 1121d; at the same time, the substrate layer 1121d can also play a role in protecting the collector 111.

[0275] In some embodiments, the base layer 1121d is an insulating structural layer.

[0276] The substrate layer 1121d is an insulating structural layer, that is, the material of the substrate layer 1121d includes insulating material, so that the insulating layer 112 can better separate the current collector 111 it covers from the external environment (such as the electrolyte or another adjacent electrode 11), so as to protect the current collector 111 and reduce the occurrence of short circuit of the current collector 111; for example, the material of the substrate layer 1121d can include polypropylene.

[0277] In this embodiment, the base material layer 1121 d is an insulating structure layer to reduce the risk of short circuit of the current collector 111 .

[0278] refer to Figure 6 、 Figure 8 、 Figure 12 In some embodiments, the thickness of the substrate layer 1121d ranges from 6 μm to 20 μm.

[0279] The thickness of the substrate layer 1121d is the size of the substrate layer 1121d in the arrangement direction of the substrate layer 1121d and the adhesive layer 1121e. When the sub-insulating layer 1121 is located on both sides of the current collector 111 along the thickness direction Z of the current collector 111, the substrate layer 1121d and the adhesive layer 1121e are arranged along the thickness direction Z of the current collector 111. At this time, the thickness of the substrate layer 1121d refers to the size of the substrate layer 1121d in the thickness direction Z of the current collector 111, and the size range is 6μm to 20μm; for example, the size can be 6μm, 8μm, 10μm, 12μm, 14μm, 16μm, 18μm, 20μm or other values.

[0280] For example, the thickness of the substrate layer 1121 d may be 6 μm. In this case, the thickness of the substrate layer 1121 d is relatively thin, so that the negative impact of the sub-insulating layer 1121 on the energy density of the battery cell 100 is relatively small.

[0281] For example, the thickness of the substrate layer 1121d can be 13 μm. The substrate layer 1121d has a certain thickness. At this time, the substrate layer 1121d can not only protect the current collector 111, but also reduce the risk of the protruding structure 1112 piercing the insulating layer 112 and the adjacent diaphragm 12; at the same time, it can also reduce the negative impact of the sub-insulating layer 1121 on the energy density of the battery cell 100.

[0282] For example, the thickness of the substrate layer 1121d can be 20 μm. In this case, the thickness of the substrate layer 1121d is relatively thick, so as to better protect the current collector 111 and better reduce the risk of the protruding structure 1112 piercing the insulating layer 112 and the adjacent diaphragm 12.

[0283] This embodiment provides some thickness ranges of the substrate layer 1121d so that it is difficult for the protruding structure 1112 to pierce the substrate layer 1121d, and the substrate layer 1121d can provide protection for the current collector 111; this setting can also make the substrate layer 1121d less likely to be broken down by static electricity, so that the substrate layer 1121d can better provide protection for the current collector 111.

[0284] In some embodiments, the adhesive layer 1121e is an adhesive structural layer.

[0285] The bonding layer 1121e is a sticky structural layer, that is, the material of the bonding layer 1121e includes a sticky material, so that the bonding layer 1121e can bond the substrate layer 1121d to the current collector 111, and make the substrate layer 1121d not easily separated from the current collector 111, so that the substrate layer 1121d can better and more stably play the role of protecting the current collector 111; at the same time, the viscosity of the bonding layer can also provide resistance for the protruding structure 1112 to penetrate the insulating layer 112, so that the protruding structure 1112 is less likely to penetrate the insulating layer 112; for example, the material of the bonding layer 1121e includes polyacrylate.

[0286] It can be understood that when the sub-insulating layer 1121 includes a first part 1121a, a second part 1121b and a third part 1121c, at least a portion of the adhesive layer 1121e of the first part 1121a is bonded to the adhesive layer 1121e of another first part 1121a, the adhesive layer 1121e of the second part 1121b is bonded to the blank area 1111c of the current collector 111, and the adhesive layer 1121e of the third part 1121c is bonded to the transition part 1132 of the active material layer 113.

[0287] In the technical solution of this embodiment, the adhesive layer 1121e is a viscous structural layer to adhere the substrate layer 1121d to the current collector 111 and / or the active material layer 113; at the same time, the adhesive layer 1121e can also cover the protruding structure 1112 to reduce the risk of the protruding structure 1112 piercing the insulating layer 112.

[0288] refer to Figure 6 、 Figure 8 、 Figure 12 In some embodiments, the thickness of the adhesive layer 1121e ranges from 3 μm to 10 μm.

[0289] The thickness of the adhesive layer 1121e is the size of the adhesive layer 1121e in the arrangement direction of the adhesive layer 1121e and the substrate layer 1121d. When the sub-insulating layer 1121 is located on both sides of the current collector 111 along the thickness direction Z of the current collector 111, the substrate layer 1121d and the adhesive layer 1121e are arranged along the thickness direction Z of the current collector 111. At this time, the thickness of the substrate layer 1121d refers to the size of the substrate layer 1121d in the thickness direction Z of the current collector 111, and the size range is 3μm to 10μm; for example, the size can be 3μm, 4μm, 5μm, 6μm, 6.5μm, 7μm, 8μm, 9μm, 10μm or other values.

[0290] For example, the thickness of the adhesive layer 1121 e may be 3 μm. In this case, the thickness of the adhesive layer 1121 e is relatively thin, so that the negative impact of the sub-insulating layer 1121 on the energy density of the battery cell 100 is relatively small.

[0291] For example, the thickness of the adhesive layer 1121e can be 6.5 μm. The adhesive layer 1121e has a certain thickness. At this time, the adhesive layer 1121e can not only fix the substrate layer 1121d, but also cover the protruding structure 1112 to reduce the risk of the protruding structure 1112 piercing the insulating layer 112 and the adjacent diaphragm 12; at the same time, it can also reduce the negative impact of the sub-insulating layer 1121 on the energy density of the battery cell 100.

[0292] For example, the thickness of the adhesive layer 1121e can be 10 μm. In this case, the thickness of the adhesive layer 1121e is relatively thick, which can not only better fix the substrate layer 1121d, but also better cover the protruding structure 1112 to reduce the risk of the protruding structure 1112 piercing the insulating layer 112 and the adjacent diaphragm 12.

[0293] This embodiment provides some thickness ranges of the adhesive layer 1121e so that the adhesive layer 1121e can more stably bond the substrate layer 1121d to the current collector 111 and / or the active material layer 113, while also preventing the protruding structure 1112 from piercing the insulating layer 112.

[0294] refer to Figure 6 、 Figures 8 to 10 In some embodiments, the size of the insulating layer 112 in the width direction of the current collector 111 ranges from 0.3 mm to 12 mm.

[0295] The size of the insulating layer 112 in the width direction Y of the current collector 111 is positively correlated with the width of the current collector 111 that the insulating layer 112 can cover, and is also positively correlated with the length of the protruding structure 1112 that the insulating layer 112 can cover; the size of the insulating layer 112 in the width direction of the current collector 111 ranges from 0.3 mm to 12 mm. For example, the size can be 0.3 mm, 3.25 mm, 6.15 mm, 9.05 mm, 12 mm or other values.

[0296] The size range of the insulating layer 112 in the width direction Y of the current collector 111 is 0.3 mm to 12 mm, so that the insulating layer 112 can be more stably connected to the current collector 111, and the insulating layer 112 can cover the protruding structure 1112, thereby reducing the risk of the protruding structure 1112 piercing the adjacent diaphragm 12 and short-circuiting with the adjacent electrode 11.

[0297] For example, the size of the insulating layer 112 in the width direction Y of the current collector 111 is 0.3 mm. On the premise that the insulating layer 112 can cover the protruding structure 1112 and be connected to the current collector 111, this setting can better reduce the space occupied by the insulating layer 112, thereby reducing the negative impact of the insulating layer 112 on the energy density of the battery cell 100; at the same time, this setting can also better reduce the area of ​​the active material layer 113 covered by the insulating layer 112, thereby reducing the negative impact of the insulating layer 112 on the charge and discharge performance of the electrode 11.

[0298] For example, the size of the insulating layer 112 in the width direction Y of the current collector 111 is 6.15 mm. At this time, the insulating layer 112 can also adapt to the larger protruding structure 1112, and can better cover the protruding structure 1112 and be more stably connected to the current collector 111; at the same time, this setting can also reduce the space occupied by the insulating layer 112, and reduce the negative impact of the insulating layer 112 on the energy density of the battery cell 100; this setting can also reduce the area of ​​the active material layer 113 covered by the insulating layer 112, thereby reducing the negative impact of the insulating layer 112 on the charge and discharge performance of the electrode 11.

[0299] For example, the size of the insulating layer 112 in the width direction Y of the current collector 111 is 12 mm. At this time, the insulating layer 112 can also adapt to more protrusion structures 1112 of different sizes, and can better cover the protrusion structures 1112 to reduce the risk of the protrusion structures 1112 piercing the insulating layer 112 and the adjacent diaphragm 12; at the same time, this setting can also make the insulating layer 112 more stably connected to the current collector 111, reducing the risk of the insulating layer 112 falling off due to long-term immersion in electrolyte.

[0300] This embodiment provides a range of widths of the insulating layer 112 so that the insulating layer 112 can not only cover the protruding structure 1112 but also be stably connected to the current collector 111 and / or the active material layer 113; at the same time, it can also reduce the space occupied by the insulating layer 112 and reduce the negative impact of the insulating layer 112 on the energy density of the battery cell 100.

[0301] In some embodiments, the peel strength of the insulating layer 112 ranges from 15 N / m (Newtons per meter) to 20 N / m.

[0302] The peel strength of the insulating layer 112 refers to the force required to peel the insulating layer 112 of unit width from the current collector 111. The peel strength of the insulating layer 112 reflects the bonding strength of the insulating layer 112 to the current collector 111, and can also reflect the bonding stability of the insulating layer 112 when immersed in the electrolyte; the peel strength range of the insulating layer 112 is 15N / m to 20N / m. For example, the peel strength can be 15N / m, 16N / m, 17N / m, 18N / m, 19N / m, 20N / m or other values.

[0303] For example, after the insulating layer 112 is immersed in the electrolyte for 1000 hours, the peel strength of the insulating layer 112 is in the range of 15N / m to 20N / m, so that the insulating layer 112 can be stably connected to the current collector 111, thereby reducing the risk of short circuit of the pole piece 11 caused by detachment of the insulating layer 112.

[0304] For the test of the peel strength of the insulating layer 112, the insulating layer 112 can be bonded to a sample (such as copper foil) with the same size and material as the current collector 111; then, the sample with the insulating layer 112 adhered thereto is soaked in the electrolyte for a period of time and taken out, and the soaking time can be set as needed (for example, 1000 hours); then, the soaked sample is bonded to a stainless steel plate, and the sample is compacted so that the sample can be stably bonded to the stainless steel plate; then, one end of the insulating layer 112 is clamped by a tensile testing machine, and the insulating layer 112 is pulled up at a preset stable speed until the insulating layer 112 detaches from the sample, and the displacement and force in the process are recorded by the tensile testing machine.

[0305] For example, the insulating layer 112 is an insulating tape with a thickness of 13 μm and a width of 8 mm, and the sample is an aluminum foil with a thickness of 13 μm. The insulating tape is bonded to the aluminum foil; the aluminum foil bonded with the insulating tape is soaked in an electrolyte at 70°C for 200 hours, 400 hours, 600 hours, 800 hours, and 1000 hours respectively, and then taken out. At this time, the insulating tape does not fall off; a high-speed rail tensile test machine is used to bond the soaked aluminum foil to a stainless steel plate with double-sided tape, with one side of the insulating tape facing outward. And compact it with a pressure roller to fix the entire sample on the tensile testing machine; use the tensile testing machine to clamp one end of the tape and pull the tape upward at a speed of 50 mm / min (millimeter per minute) until the tape is completely peeled off from the aluminum foil, and record the displacement and force in the process; when the base material layer 1121d of the insulating tape is polypropylene with a thickness of 10 μm and the adhesive layer 1121e is polyacrylate with a thickness of 3 μm, the peel strength of the insulating tape is 19.21 N / m.

[0306] This embodiment provides some peel strength ranges for the insulating layer 112 , so that the insulating layer 112 is difficult to separate from the current collector 111 and / or the active material layer 113 , thereby enabling the insulating layer 112 to still have strong connection stability in an electrolyte infiltration environment.

[0307] refer to Figure 4 、 Figure 5 In some embodiments, the battery cell 100 further includes an electrode assembly 10 , which includes a positive electrode sheet 114 , a separator 12 , and a negative electrode sheet 115 that are sequentially spaced apart; the electrode sheet 11 is the positive electrode sheet 114 .

[0308] The electrode piece 11 is a positive electrode piece 114. In this case, the current collector 111 can be aluminum foil. The active material layer 113 can include cobalt, nickel, manganese, lithium iron phosphate, etc. The insulating layer 112 is arranged on the end surface 1111a of the main body 1131 close to the pole ear 1113, and the insulating layer 112 covers a part of the pole ear 1113. The second insulating layer 112 is arranged on the end surface 1111a of the main body 1131 away from the pole ear 1113.

[0309] For example, when the electrode 11 is a positive electrode 114, the insulating layer 112 includes a first part 1121a, a second part 1121b and a third part 1121c connected in sequence, wherein the first part 1121a extends beyond the current collector 111 and covers part of the electrode ear 1113, the second part 1121b covers the blank area 1111c of the current collector 111, and the third part 1121c covers the transition part 1132 of the active material layer 113.

[0310] The burrs generated during processing of the positive electrode sheet 114 and the short circuit between the active material layer 113 of the negative electrode sheet 115 may cause greater harm. Therefore, in this embodiment, the electrode sheet 11 is used as the positive electrode sheet 114 to reduce the safety risk caused by the burr short circuit.

[0311] In some embodiments, the positive electrode sheet 114 is prepared as follows:

[0312] The active material layer 113 of the positive electrode sheet 114 includes active material lithium iron phosphate (LiFePO4, LFP), binder polyvinylidene fluoride (PVDF) and conductive carbon black (Super P), which are uniformly mixed in a ratio of lithium iron phosphate: polyvinylidene fluoride: conductive carbon black = 95:3:2 to obtain a first mixed slurry.

[0313] The dispersion solvent is 1-methyl-2-pyrrolidone (NMP), and the first mixed slurry is dispersed using the dispersion solvent to obtain a positive electrode slurry.

[0314] The positive electrode slurry is coated on both side surfaces 1111b of the aluminum foil (current collector 111 of the positive electrode sheet 114), and is dried, rolled, die-cut and slit in sequence.

[0315] Insulating tape is used as the sub-insulating layer 1121, and two insulating tapes are respectively attached to the die-cut edges on both sides of the aluminum foil. The parts of the two insulating tapes are attached to each other to form the insulating layer 112; the widths of the parts of the two insulating tapes covering the corresponding active material layer 113 are 0.2mm and 0.8mm respectively.

[0316] In some embodiments, the negative electrode sheet 115 is prepared as follows:

[0317] The active material layer 113 of the negative electrode sheet 115 includes active material graphite, binder styrene butadiene rubber (SBR) and conductive carbon black, which are uniformly mixed in a ratio of graphite: styrene butadiene rubber: conductive carbon black = 94:4:2 to obtain a second mixed slurry.

[0318] The dispersion solvent is ionized water, and the second mixed slurry is dispersed using the dispersion solvent to obtain a negative electrode slurry.

[0319] The negative electrode slurry is coated on both side surfaces 1111 b of the copper foil (current collector 111 of the negative electrode sheet 115 ), and is dried, rolled, die-cut and slit in sequence to obtain the negative electrode sheet 115 .

[0320] In some embodiments, the sub-insulating layer 1121 is an insulating tape, and the material of its base material layer 1121d is polypropylene (PP), and the thickness of the base material layer 1121d is 10 μm; the material of the adhesive layer 1121e is polyacrylate (PA), and the thickness of the adhesive layer 1121e is 3 μm; the total thickness of the sub-insulating layer 1121 is 13 μm, and the size of the sub-insulating layer 1121 in the width direction Y of the current collector 111 is 8 mm.

[0321] In some embodiments, the base film thickness of the diaphragm 12 is 7 μm, and the base film material is polypropylene.

[0322] In some embodiments, the electrode assembly 10 is prepared as follows:

[0323] The prepared positive electrode sheet 114 , separator 12 and negative electrode sheet 115 are wound and then hot pressed to obtain the electrode assembly 10 .

[0324] In some embodiments, the electrolyte is prepared as follows:

[0325] Lithium hexafluorophosphate (LFPF6) was added gradually into ethylene carbonate (EC), and the mass fraction of the lithium hexafluorophosphate in the electrolyte was controlled to be 12.5%, thereby obtaining an electrolyte.

[0326] In some embodiments, the assembly process of the battery cell 100 is as follows:

[0327] Place the electrode assembly 10 in the outer packaging shell 20 (such as an aluminum shell), weld the pole ear portions 1113 of the positive electrode sheet 114 and the negative electrode sheet 115 to the electrode terminal 40 of the end cover 30, and dry them; inject the prepared electrolyte into the shell 20, and then let it rest, form, and separate the capacity to complete the preparation of the battery device 1000.

[0328] In some embodiments, the battery cell 100 includes a pole piece 11 , which includes a current collector 111 , an active material layer 113 , and an insulating layer 112 .

[0329] The current collector 111 includes a current collector body 1111 , which includes two side surfaces 1111 b and two end surfaces 1111 a , with protruding structures 1112 formed on the end surfaces 1111 a ; the current collector 1111 also includes a pole ear portion 1113 , which is connected to the end surface 1111 a .

[0330] The protruding structure 1112 includes a first protruding portion 1112a, and the length of the first protruding portion 1112a ranges from 40μm to 200μm; the protruding structure 1112 also includes a second protruding portion 1112b, the second protruding portions 1112b are arranged at intervals, and a connecting portion 1112c is provided between two adjacent second protruding portions 1112b, and the length of the second protruding portion 1112b ranges from 15μm to 40μm.

[0331] The active material layer 113 includes a main body 1131 and a transition portion 1132 connected to the main body 1131. The transition portion 1132 is located on the side of the main body 1131 facing the end face 1111a. The thickness of the transition portion 1132 gradually decreases in the direction from the main body 1131 to the end face 1111a. The portion of the current collector 111 that is not covered by the active material layer 113 is a blank area 1111c. The blank area 1111c is located on the side 1111b of the current collector main body 1111 and close to the pole ear portion 1113.

[0332] The insulating layer 112 includes two sub-insulating layers 1121, each connected to the two side surfaces 1111b. The thickness of each sub-insulating layer 1121 can be set based on the thickness of the first protrusion 1112a and the second protrusion 1112b. The sub-insulating layer 1121 includes a first portion 1121a, a second portion 1121b, and a third portion 1121c, which are connected in sequence. The first portion 1121a extends beyond the current collector 111 and covers a portion of the tab 1113. The first portion 1121a can also connect to another first portion 1121a to cover the corresponding end surface 1111a and the protrusion 1112. The second portion 1121b covers the blank area 1111c of the current collector 111, and the third portion 1121c covers at least a portion of the transition portion 1132.

[0333] The insulating layer 112 includes a base layer 1121 d and an adhesive layer 1121 e , wherein one side of the adhesive layer 1121 e is connected to the current collector 111 , and the other side is connected to the base layer 1121 d .

[0334] In a second aspect, some embodiments of the present application provide a battery device 1000, comprising the battery cell 100 provided by some embodiments of the first aspect; in the battery device 1000, the protruding structure 1112 of the pole piece 11 is not easy to pierce the adjacent diaphragm 12 and cause a short circuit, thereby enabling the battery device 1000 to have higher stability.

[0335] In a third aspect, some embodiments of the present application further provide an energy storage device 1 , comprising the battery cell 100 provided by some embodiments of the first aspect, or the battery device 1000 provided by some embodiments of the second aspect.

[0336] Energy storage device 1 includes one or more battery clusters to increase the voltage and capacity of energy storage device 1. A battery cluster may include multiple battery devices 1000, which are connected in series via a busbar to increase the voltage of energy storage device 1. When energy storage device 1 includes multiple battery clusters, the battery clusters are connected in parallel to increase the capacity of energy storage device 1.

[0337] The energy storage device 1 can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems. The energy storage device 1 can store electrical energy as needed and output it at the appropriate time. For example, the energy storage device 1 can store electrical energy during low-power periods and provide electrical energy to relevant users or electrical equipment during peak power periods. The energy storage system provided in the embodiments of the present application can be any power system that requires the energy storage device 1.

[0338] In some embodiments, the energy storage device 1 is an energy storage container or an energy storage cabinet.

[0339] In some embodiments, the energy storage device 1 may include a cabinet and one or more battery clusters, where the battery clusters are housed in the cabinet.

[0340] In some embodiments, the energy storage device 1 may include modules such as a thermal management module, a main control module, a master control module, a power distribution module, and a fire protection module.

[0341] As an example, the thermal management module may include a liquid cooling unit that provides cooling liquid for regulating the temperature of the battery cells 100 to each battery device 1000 through a pipeline.

[0342] For example, the master control module can serve as the battery management unit (BMU) of a battery cluster, monitoring and managing the cluster. The master control module can monitor information such as the battery cluster's current, voltage, power, or temperature. For example, it can control the battery cluster's charge and discharge current and voltage. The master control module includes modules such as the slave battery management unit (SBMU) and the fusion switch.

[0343] As an example, the master control module can serve as the battery management unit of the energy storage device 1, used to monitor and manage the energy storage device 1. The master control module can monitor information such as the current, voltage, power, state of charge, or temperature of the energy storage device 1. For example, it can control the charge and discharge current and voltage of the energy storage device 1. As an example, the master control module includes modules such as an insulation monitoring module (IMM), a master battery management unit (MBMU), an Ethernet (ETH), and a fiber optic conversion module.

[0344] As an example, the fire protection module includes a control panel, detectors, alarm devices, etc., which are used to detect, alarm or extinguish fires in the energy storage system.

[0345] As an example, the power distribution module can be used to distribute power to modules in the energy storage device 1 that require power.

[0346] Fourthly, reference Figure 13 Some embodiments of the present application also provide an energy storage system, including a power conversion device 2 and an energy storage device 1 provided in some embodiments of the third aspect, wherein the power conversion device 2 is used to electrically connect the power generation device 3 and the energy storage device 1.

[0347] The energy storage system may include one or more energy storage devices 1 and a power converter system 2 (PCS). The power converter system 2 is connected between the power generation device 3 and the energy storage device 1. The power generation device 3 is used to generate electrical energy, and the electrical energy generated by the power generation device 3 can be stored in the energy storage device 1 through the power converter system 2. As an example, the power generation device 3 may be a solar panel, a hydropower generation device, a thermal power generation device, a wind power generation device, etc. The specific type of the power generation device 3 is not limited in this application.

[0348] In a fifth aspect, some examples of the present application further provide an electrical device, comprising the battery cell 100 provided in some embodiments of the first aspect, or the battery device 1000 provided in some embodiments of the second aspect; or the energy storage device 1 provided in some embodiments of the third aspect, or the energy storage system provided in some embodiments of the fourth aspect. The battery cell 100 or the battery device 1000 is used to store or provide electrical energy.

[0349] Sixth aspect, reference Figure 14 Some embodiments of the present application further provide a charging network, comprising a charging pile 4 and the energy storage device 1 provided in some embodiments of the third aspect, or the energy storage system provided in some embodiments of the fourth aspect. The energy storage device 1 or the energy storage system is used to provide electrical energy to the charging pile 4.

[0350] Charging station 4 is electrically connected to energy storage device 1, which is used to provide electrical energy to charging station 4. Charging station 4 is electrically connected to battery device 1000 in energy storage device 1 via a cable, and battery device 1000 can provide its stored electrical energy to charging station 4. Charging station 4 has one or more connectors 5, which are used to connect to electrical equipment (such as vehicles) to replenish energy to the electrical equipment.

[0351] The energy storage device 1 can be located inside the charging pile 4 (for example, an integrated storage and charging device), or outside the charging pile 4 .

[0352] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: The invention comprises a pole piece, wherein the pole piece comprises: a current collector, the current collector comprising two end surfaces located at opposite ends along the width direction of the current collector, the current collector further comprising two side surfaces located at opposite sides along the thickness direction of the current collector, the end surfaces having protruding structures formed thereon; An insulating layer is provided on the current collector, and the insulating layer at least covers the end surface and the protruding structure.

2. The battery cell according to claim 1, wherein: The insulating layer wraps the protruding structure.

3. The battery cell according to claim 1 or 2, characterized in that: The thickness of the insulating layer ranges from 9 μm to 30 μm.

4. The battery cell according to claim 3, characterized in that The puncture strength of the insulating layer is greater than or equal to 300 gf.

5. The battery cell according to any one of claims 1 to 4, characterized in that: The protrusion structure includes at least two first protrusions spaced apart along the length direction of the current collector, wherein the first protrusions are formed on the end surface; The insulating layer covers the first protrusion.

6. The battery cell according to claim 5, characterized in that The length of the first protrusion ranges from 40 μm to 200 μm.

7. The battery cell according to claim 5 or 6, characterized in that: In the longitudinal direction of the current collector, the number of the first protrusions within a size range of 1 mm is greater than or equal to 1; The thickness of the insulating layer ranges from 13 μm to 30 μm.

8. The battery cell according to any one of claims 1 to 4, characterized in that: The protrusion structure further includes a plurality of second protrusions spaced apart along the length direction of the current collector, a connecting portion is provided between two adjacent second protrusions, and the connecting portion and the second protrusions are both formed on the end surface; The length of the connecting portion is smaller than that of the second protruding portion, and the insulating layer covers the second protruding portion and the connecting portion.

9. The battery cell according to claim 8, characterized in that The length of the second protrusion is in the range of 15 μm to 40 μm.

10. The battery cell according to claim 9, characterized in that In the longitudinal direction of the current collector, the number of the second protrusions within a size range of 1 mm is in a range of 3 to 5; The thickness of the insulating layer ranges from 9 μm to 13 μm.

11. The battery cell according to claim 9, characterized in that In the longitudinal direction of the current collector, the number of the second protrusions within a size range of 1 mm ranges from 5 to 15; The thickness of the insulating layer ranges from 13 μm to 30 μm.

12. The battery cell according to any one of claims 1 to 11, characterized in that: The insulating layer includes two sub-insulating layers corresponding to the two side surfaces, the sub-insulating layer includes a first portion and a second portion connected to the first portion, and the second portion is connected to the side surfaces; At least a portion of the first portion is connected to the first portion of another adjacent sub-insulating layer, and the two first portions cover the protruding structure.

13. The battery cell according to claim 12, characterized in that: In the width direction of the current collector, a size of the first portion ranges from 0.2 mm to 6 mm.

14. The battery cell according to claim 12 or 13, characterized in that: The electrode further includes an active material layer provided on the side surface, wherein the active material layer covers at least a portion of the side surface; The sub-insulating layer is connected to the active material layer.

15. The battery cell according to claim 14, characterized in that The active material layer covers part of the side surface and forms a blank area on a side of the side surface close to the end surface, and the second portion covers at least part of the blank area.

16. The battery cell according to claim 15, characterized in that In the width direction of the current collector, the size of the blank area is less than or equal to 5 mm.

17. The battery cell according to claim 15 or 16, characterized in that: The sub-insulating layer further includes a third portion connected to a side of the second portion opposite to the first portion, the second portion covers the blank area, and the third portion covers a portion of the active material layer.

18. The battery cell according to claim 17, characterized in that The active material layer includes a main body and a transition portion connected to the main body, wherein the transition portion is provided on a side of the main body facing the end surface, and a thickness of the transition portion gradually decreases along a direction from the main body to the end surface; The third portion covers at least a portion of the transition portion.

19. The battery cell according to claim 18, characterized in that In the width direction of the current collector, the size of the third portion ranges from 0.1 mm to 1 mm.

20. The battery cell according to any one of claims 12 to 19, characterized in that: The sub-insulating layer includes a base material layer and an adhesive layer provided on the base material layer, wherein the adhesive layer is provided on a side of the base material layer facing the current collector.

21. The battery cell according to claim 20, characterized in that The substrate layer is an insulating structural layer.

22. The battery cell according to claim 20 or 21, characterized in that: The thickness of the substrate layer ranges from 6 μm to 20 μm.

23. The battery cell according to any one of claims 20 to 22, characterized in that: The adhesive layer is a sticky structural layer.

24. The battery cell according to any one of claims 20 to 23, characterized in that: The thickness of the adhesive layer ranges from 3 μm to 10 μm.

25. The battery cell according to any one of claims 1 to 24, characterized in that: In the width direction of the current collector, the size of the insulating layer ranges from 0.3 mm to 12 mm.

26. The battery cell according to any one of claims 1 to 25, characterized in that: The peel strength of the insulating layer is in the range of 15 N / m to 20 N / m.

27. The battery cell according to any one of claims 1 to 26, characterized in that: The battery cell further comprises an electrode assembly, wherein the electrode assembly comprises a positive electrode sheet, a separator and a negative electrode sheet which are sequentially spaced apart; The electrode is the positive electrode.

28. A battery device, characterized in that: The invention comprises a battery cell according to any one of claims 1 to 27.

29. An energy storage device, characterized in that: The method comprises a plurality of battery cells according to any one of claims 1 to 27, or a plurality of battery devices according to claim 28.

30. An energy storage system, characterized in that: It comprises a power conversion device and the energy storage device as claimed in claim 29, wherein the power conversion device is used to electrically connect the power generation device and the energy storage device.

31. An electrical device, characterized in that: The method comprises the battery cell according to any one of claims 1 to 27, the battery device according to claim 28, the energy storage device according to claim 29, or the energy storage system according to claim 30.

32. A charging network, characterized in that: comprising a charging pile and the energy storage device according to claim 29, or the energy storage system according to claim 30; The energy storage device or the energy storage system is used to provide electrical energy to the charging pile.

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