Battery cells, related devices, systems, and charging networks

Abstract

This application relates to the field of power battery technology, and proposes a battery cell (100), related devices, systems and charging networks. The battery cell (100) includes an electrode (11), the electrode (11) includes: a current collector (111), the current collector (111) includes two end faces (1111a) and two side faces (1111b), and a protruding structure (1112) is formed on the end face (1111a); an insulating layer (112) is disposed on the current collector (111), and the insulating layer (112) at least covers the end face (1111a) and the protruding structure (1112). In the battery cell (100) provided in this application 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 separator (12) adjacent to the electrode (11) and cause the two adjacent electrodes (11) to short-circuit, 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 insulating layer (112) wraps around the protruding structure (1112) and fixes the position of the protruding structure (1112) to reduce the risk of the protruding structure (1112) piercing the adjacent separator (12), thereby reducing the risk of short circuit between adjacent electrodes (11) and improving the safety and stability of the battery cell (100).

Description

Battery cell, related device, system and charging network TECHNICAL FIELD

[0001] The application belongs to the technical field of power batteries, and particularly relates to a battery cell, a related device, a system and a charging network. BACKGROUND

[0002] Energy saving and emission reduction is the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their energy saving and environmental protection advantages. For electric vehicles, battery technology is an important factor for their development.

[0003] During the manufacturing process of the battery, the pole piece needs to be die-cut to form the tab. After die-cutting, burrs are easily generated on the section of the pole piece, the burrs are easy to pierce the diaphragm to cause short circuit between adjacent pole pieces, and also easy to cause the risk of thermal runaway of the battery to increase.

[0004] SUMMARY

[0005] In view of the above problems, the application provides a battery cell, a related device, a system and a charging network, which can alleviate the problem of burrs piercing the diaphragm to cause short circuit between adjacent pole pieces.

[0006] In a first aspect, some embodiments of the application provide a battery cell, comprising a pole piece, the pole piece comprising: a current collector, the current collector comprising two end faces located at opposite ends along the width direction of the current collector, the current collector further comprising two side faces located at opposite sides along the thickness direction of the current collector, and a protruding structure formed on the end face; and an insulating layer arranged on the current collector, the insulating layer covering at least the end face and the protruding structure.

[0007] In the technical scheme of the embodiment, the end face of the current collector is formed with a protruding structure, the protruding structure is easy to pierce the diaphragm adjacent to the pole piece and cause short circuit between the two adjacent pole pieces, thereby causing short circuit of the battery cell. Accordingly, the insulating layer is arranged and covers the protruding structure, the insulating layer wraps the protruding structure and fixes the position of the protruding structure, so as to reduce the risk of the protruding structure piercing the adjacent diaphragm, thereby reducing the risk of short circuit between the adjacent pole pieces and improving the safety and stability of the battery cell.

[0008] In some embodiments, the insulating layer wraps the protruding structure.

[0009] In the technical scheme of the embodiment, the insulating layer wraps the protruding structure, so that the protruding structure is not easy to pierce the insulating layer, and the insulating layer wrapping the protruding structure can also fix the protruding structure, so that the protruding structure is not easy to swing relative to the current collector and pierce the diaphragm.

[0010] In some embodiments, the thickness of the insulating layer ranges from 9 to 30 microns.

[0011] The technical solution of the embodiment provides the thickness range of the insulation layer, so that the thickness of the insulation layer is greater than or equal to 9 μm. After the insulation layer covers the protruding structure, the insulation layer with the thickness range can better cover the protruding structure and has a certain strength, so that the protruding structure is difficult to pierce the insulation layer, thereby reducing the risk of short circuit of the adjacent pole piece and improving the safety and stability of the battery cell. The thickness of the insulation layer is less than or equal to 30 μm. On the premise that the protruding structure is difficult to pierce the insulation layer, the thickness of the insulation layer is limited, so that the thickness of the insulation layer is not too large, thereby reducing the negative influence of the insulation layer on the energy density of the battery cell.

[0012] In some embodiments, the needle penetration strength of the insulation layer is greater than or equal to 300 gf.

[0013] The technical solution of the embodiment provides the needle penetration strength range of some insulation layers, so that the protruding structure is difficult to pierce the insulation layer, thereby enabling the insulation layer to better reduce the risk of short circuit of the protruding structure and the adjacent pole piece.

[0014] In some embodiments, the protruding structure includes at least two first protruding parts spaced apart along the length direction of the current collector, and the first protruding part is formed on the end face; and the insulation layer covers the first protruding part.

[0015] The technical solution of the embodiment provides the specific structure of some protruding structures, so that the protruding structure includes the first protruding part arranged at intervals, and the insulation layer can cover the first protruding part, so that the insulation layer can adapt to the structure of the first protruding part.

[0016] In some embodiments, the length of the first protruding part ranges from 40 μm to 200 μm.

[0017] The technical solution of the embodiment provides the size range of some first protruding parts, and the insulation layer can adapt to the structure of the first protruding part, so that the insulation layer can cover first protruding parts of different sizes, thereby making the protruding structures of different sizes difficult to pierce the insulation layer.

[0018] In some embodiments, in the length direction of the current collector, the number of the first protruding parts within the size range of 1 mm is greater than or equal to 1; and the thickness of the insulation layer ranges from 13 μm to 30 μm.

[0019] The technical solution of the embodiment provides the arrangement structure of some first protruding parts and the specific thickness range of the corresponding insulation layer, so that the insulation layer can better adapt to the size and arrangement structure of the first protruding part, thereby making the insulation layer better cover the first protruding part and making the first protruding part difficult to pierce the insulation layer.

[0020] In some embodiments, the protruding structure further comprises a plurality of second protruding portions arranged at intervals along the length direction of the current collector, and a connecting portion is arranged between adjacent two second protruding portions, and the connecting portion and the second protruding portion are formed on the end face; the length of the connecting portion is less than the length of the second protruding portion; and the insulating layer covers the second protruding portion and the connecting portion.

[0021] The technical scheme of the embodiment provides specific structures of some protruding structures, so that the protruding structure comprises second protruding portions arranged at intervals and a connecting portion arranged between adjacent second protruding portions; and the insulating layer can cover the second protruding portion, so that the insulating layer can adapt to the structure of the second protruding portion.

[0022] In some embodiments, the length of the second protruding portion ranges from 15 μm to 40 μm.

[0023] The technical scheme of the embodiment provides a size range of some second protruding portions, and the insulating layer can adapt to the structure of the second protruding portion, so that the insulating layer can cover second protruding portions of different sizes, and thus protruding structures of different sizes are difficult to pierce the insulating layer.

[0024] In some embodiments, in the length direction of the current collector, the number of second protruding portions in a size range of 1 mm ranges from 3 to 5; and the thickness of the insulating layer ranges from 9 μm to 13 μm.

[0025] The technical scheme of the embodiment provides a specific arrangement structure of some second protruding portions and a specific thickness range of the corresponding insulating layer, so that the insulating layer can better adapt to the size and arrangement structure of the second protruding portion, so that the insulating layer can better cover the second protruding portion, and the second protruding portion is difficult to pierce the insulating layer.

[0026] In some embodiments, in the length direction of the current collector, the number of second protruding portions in a size range of 1 mm ranges from 5 to 15; and the thickness of the insulating layer ranges from 13 μm to 30 μm.

[0027] The technical scheme of the embodiment provides another arrangement structure of some second protruding portions and a specific thickness range of the corresponding insulating layer, so that the insulating layer can better adapt to the size and arrangement structure of the second protruding portion, so that the insulating layer can better cover the second protruding portion, and the second protruding portion is difficult to pierce the insulating layer.

[0028] In some embodiments, the insulating layer comprises two sub-insulating layers corresponding to the two side faces, the sub-insulating layer comprises a first portion and a second portion connected to the first portion, and the second portion is connected to the side face; at least part of the first portion is connected to the first portion of another adjacent sub-insulating layer, and the two first portions clamp the protruding structure to guide the protruding structure to extend along the width direction of the current collector.

[0029] The technical scheme of the embodiment provides 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, so as to guide and limit the extension direction of the protruding structure through the two first parts, thereby preventing the protruding structure from being bent to the two sides and piercing the sub-insulating layer or the adjacent diaphragm.

[0030] In some embodiments, in the width direction of the current collector, the size of the first part ranges from 0.2 mm to 6 mm.

[0031] The technical scheme of the embodiment provides a size range of the first part, so that the first part can better cover the protruding structure to reduce the risk of the protruding structure piercing the insulating layer, and can also reduce the occupation of the first part to the internal space of the battery monomer and the negative impact of the insulating layer on the energy density of the battery monomer.

[0032] In some embodiments, the pole piece further includes an active material layer arranged on the side surface, the active material layer covering at least part of the side surface; and the sub-insulating layer is connected to the active material layer.

[0033] In the technical scheme of the 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 falling of the insulating layer.

[0034] In some embodiments, the active material layer covers part of the side surface and forms a blank area on the side surface close to one side of the end surface, and the second part covers at least part of the blank area.

[0035] In the technical scheme of the embodiment, the second part can cover at least part of the blank area to protect the current collector, and also can reduce the area of the current collector exposed to the outside, thereby reducing the occurrence of short circuit and improving the safety performance of the battery monomer.

[0036] In some embodiments, in the width direction of the current collector, the size of the blank area is less than or equal to 5 mm.

[0037] The technical scheme of the embodiment provides a size range of the blank area, so that the sub-insulating layer can be more stably connected to the current collector through the second part, and also can reduce the negative impact of the blank area on the covered area of the active material layer, so as to reduce the negative impact of the blank area on the charge and discharge capacity of the pole piece.

[0038] In some embodiments, the sub-insulating layer further includes a third part connected to the second part on the side opposite to the first part, the second part covers the blank area, and the third part covers part of the active material layer.

[0039] The technical scheme of the embodiment makes the sub-insulating layer further include a third part, and makes the third part cover a part of the active material layer, so that the second part can completely cover the blank area, thereby further improving the safety performance of the battery monomer.

[0040] In some embodiments, the active material layer includes a main part and a transition part connected to the main part, the transition part is arranged on the side of the main part facing the end face, and the thickness of the transition part gradually decreases along the direction from the main part to the end face; the third part covers at least part of the transition part.

[0041] The technical scheme of the embodiment makes the active material layer include a transition part with gradually decreasing thickness, and makes the third part cover at least part of the transition part, so as to reduce the height of the third part protruding from the active material layer, thereby reducing the negative impact of the insulating layer on the energy density of the battery monomer, and further relieving the stress concentration of the pole piece at the insulating layer.

[0042] In some embodiments, in the width direction of the current collector, the size of the third part ranges from 0.1mm to 1mm.

[0043] The technical scheme of the embodiment provides a size range of the third part, so that the third part can be stably connected to the transition part and not easily fall off, thereby enabling the second part to better cover the blank area and reducing the risk of short circuit and damage caused by exposure of the blank area; at the same time, the setting can also make the third part not easily protrude from the plane in which the surface of the active material layer facing the corresponding side is located, or can reduce the height of the third part protruding from the plane in which the surface of the active material layer facing the corresponding side is located, so as to reduce the stress concentration at the third part during the winding and hot pressing process, thereby reducing the damage to the pole piece.

[0044] In some embodiments, the sub-insulating layer includes a substrate layer and an adhesive layer arranged on the substrate layer, and the adhesive layer is arranged on the side of the substrate layer facing the current collector.

[0045] The technical scheme of the embodiment provides a structure of the sub-insulating layer, so that the sub-insulating layer includes an adhesive layer and a substrate layer, the substrate layer can be connected to the current collector through the adhesive layer, and the adhesive layer can cover the protruding structure, and the substrate layer can make the protruding structure difficult to pierce the insulating layer; at the same time, the substrate layer can also play a role in protecting the current collector.

[0046] In some embodiments, the substrate layer is an insulating structure layer.

[0047] The technical scheme of the embodiment makes the substrate layer an insulating structure layer, so as to reduce the risk of short circuit of the current collector.

[0048] In some embodiments, the thickness of the substrate layer ranges from 6μm to 20μm.

[0049] The technical scheme of the embodiment provides a 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; and the substrate layer is also difficult to be punctured by static electricity, so that the substrate layer can better provide protection for the current collector.

[0050] In some embodiments, the bonding layer is a sticky structure layer.

[0051] In the technical scheme of the embodiment, the bonding layer is a sticky structure layer, so as to bond the substrate layer to the current collector and / or the active material layer; meanwhile, the bonding layer can also cover the protruding structure, so as to reduce the risk of the protruding structure piercing the insulating layer.

[0052] In some embodiments, the thickness of the bonding layer ranges from 3 to 10 microns.

[0053] The technical scheme of the embodiment provides a thickness range of the bonding layer, so that the bonding layer can more stably bond the substrate layer to the current collector and / or the active material layer, and the bonding layer can also hinder the protruding structure from piercing the insulating layer.

[0054] In some embodiments, in the width direction of the current collector, the size of the insulating layer ranges from 0.3 to 12 millimeters.

[0055] The technical scheme of the embodiment provides a width range of the insulating layer, so that the insulating layer can cover the protruding structure and be stably connected to the current collector and / or the active material layer; meanwhile, the space occupied by the insulating layer can be reduced, and the negative influence of the insulating layer on the energy density of the battery cell can be reduced.

[0056] In some embodiments, the peeling strength of the insulating layer ranges from 15 to 20 N / m.

[0057] The technical scheme of the embodiment provides a peeling strength range of the insulating layer, so that the insulating layer is difficult to separate from the current collector and / or the active material layer, so that the insulating layer can still have strong connection stability in the environment of electrolyte infiltration.

[0058] In some embodiments, the battery cell further comprises an electrode assembly, the electrode assembly comprising a positive electrode sheet, a separator and a negative electrode sheet arranged in sequence with intervals; the electrode sheet is a positive electrode sheet.

[0059] In the technical scheme of the embodiment, the protruding structure caused by the processing of the positive electrode sheet is more harmful to the short circuit of the active material layer of the negative electrode sheet, so the electrode sheet is a positive electrode sheet in the embodiment, so as to reduce the safety risk caused by the short circuit of the protruding structure.

[0060] In a second aspect, some embodiments of the application also provide a battery device comprising the battery cell provided by some embodiments of the first aspect.

[0061] In a third aspect, some embodiments of the present application further provide an energy storage device, comprising a plurality of the battery cell provided by some embodiments of the first aspect, or a plurality of the battery device provided by some embodiments of the second aspect;

[0062] The battery cell or the battery device is used for storing or providing electric energy.

[0063] 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 for electrically connecting the power generation device and the energy storage device.

[0064] In a fifth aspect, some embodiments of the present application further provide a power consumption device, comprising the battery cell provided by some embodiments of the first aspect, the battery device provided by some embodiments of the second aspect, the energy storage device provided by some embodiments of the third aspect, or the energy storage system provided by some embodiments of the fourth aspect, wherein the battery cell or the battery device is used for storing or providing electric energy.

[0065] In a sixth aspect, some embodiments of the present application further provide a charging network, comprising a charging pile and the energy storage device provided by some embodiments of the third aspect, or the energy storage system provided by some embodiments of the fourth aspect, wherein the energy storage device or the energy storage system is used for providing electric energy for the charging pile.

[0066] The above description is only a summary of the technical solutions of the present application. In order to enable one of ordinary skill in the art to better understand the technical means of the present application and implement the same according to the contents of the description, and in order to enable the above and other purposes, features and advantages of the present application to be more apparent, the following specific embodiments of the present application are described in detail. BRIEF DESCRIPTION OF DRAWINGS

[0067] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a better understanding of the preferred embodiments, and are not to be considered as limitations on the present application. Moreover, in the entire drawings, the same reference numerals are used to designate the same components. In the drawings:

[0068] FIG. 1 is a structural schematic diagram of a vehicle provided by some embodiments of the present application;

[0069] FIG. 2 is an exploded structural schematic diagram of a battery device according to some embodiments of the present application;

[0070] FIG. 3 is an exploded structural schematic diagram of a battery cell according to some embodiments of the present application;

[0071] FIG. 4 is a structural schematic diagram of an electrode assembly provided by some embodiments of the present application;

[0072] Fig. 5 is a schematic diagram of a cross-sectional structure of an electrode assembly according to some embodiments of the present application;

[0073] Fig. 6 is a schematic diagram of a structure of an electrode tab according to some embodiments of the present application;

[0074] Fig. 7 is a schematic diagram of a partial enlarged view of Fig. 6 after removing an insulating layer at position A;

[0075] Fig. 8 is a schematic diagram of a cross-sectional view of Fig. 6 at position B-B;

[0076] Fig. 9 is a schematic diagram of a cross-sectional view of Fig. 6 at position C-C according to some embodiments of the present application;

[0077] Fig. 10 is a schematic diagram of a cross-sectional view of Fig. 6 at position C-C according to some other embodiments of the present application;

[0078] Fig. 11 is a schematic diagram of a partial enlarged view of Fig. 8 at position D;

[0079] Fig. 12 is a schematic diagram of a partial enlarged view of Fig. 8 at position E;

[0080] Fig. 13 is a schematic diagram of a structure of an energy storage system according to some embodiments of the present application;

[0081] Fig. 14 is a schematic diagram of a structure of a charging network according to some embodiments of the present application.

[0082] The meanings of the labels in the figures are as follows:

[0083] 1, energy storage device; 2, power conversion device; 3, power generation device; 4, charging pile; 5, connector;

[0084] 1000, battery device;

[0085] 100, battery cell;

[0086] 10, electrode assembly; 11, electrode tab; 111, current collector; 1111, current collector body; 1111a, end face; 1111b, side face; 1111c, blank area; 1112, protruding structure; 1112a, first protruding portion; 1112b, second protruding portion; 1112c, connecting portion; 1113, tab 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 portion; 1132, transition portion; 114, positive electrode tab; 115, negative electrode tab; 12, separator;

[0087] 20, housing;

[0088] 30, end cap;

[0089] 40, electrode terminal;

[0090] 200, box; 201, upper box; 202, lower box;

[0091] 2000, motor;

[0092] 3000, controller. Embodiments of the present application

[0093] The embodiments of the technical solutions of the present application will be described in detail below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0094] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion.

[0095] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise explicitly and specifically limited.

[0096] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can 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 all refer to the same embodiment, nor is it necessarily mutually exclusive or alternative embodiments to each other. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0097] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are a "or" relationship.

[0098] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two), and similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0099] In the description of the embodiments of the present application, the orientations or positional relationships indicated by the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the embodiments of the present application.

[0100] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, can be fixedly connected, or can be detachably connected, or can be integrated; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium; can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0101] At present, from the development of market situation, the application of power battery is more and more extensive. The power battery is not only applied to energy storage power supply systems such as hydroelectric, thermal, wind and solar power stations, but also widely used in electric bicycles, electric motorcycles, electric vehicles and other electric vehicles, military equipment, aerospace and other fields. With the continuous expansion of the application field of power battery, the demand of its market is also increasing.

[0102] During the manufacturing process of the battery, the pole piece needs to be die-cut to form a tab, and the pole piece is prone to burrs on its section after die-cutting. The burrs are prone to pierce the adjacent separator and contact the adjacent pole piece, thereby easily causing the short circuit of the adjacent pole piece and leading to short circuit, and further easily causing negative impact on the performance of the battery, and also easily leading to the risk of thermal runaway of the battery.

[0103] In order to alleviate the problem of burrs piercing the separator to cause the short circuit of the adjacent pole piece, the number of burrs generated during the cutting of the pole piece can be reduced, but this requires improvement of the winding and die-cutting equipment, which is too high in cost and difficult to eliminate the burrs, and a small amount of burrs on the section of the pole piece still exist the risk of piercing the separator and causing the short circuit of the adjacent pole piece.

[0104] Based on the above considerations, in order to alleviate the problem of burrs piercing the separator to cause the short circuit of the adjacent pole piece, the embodiments of the present application provide a battery monomer. Since the protruding structure is located on the end face of the current collector, the insulating layer covers the end face of the current collector, and the protruding structure is covered by the insulating layer.

[0105] In the battery monomer, 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 arrangement of the insulating layer; the insulating layer is arranged and covers the protruding structure, the protruding structure is wrapped by the insulating layer and the position of the protruding structure is fixed, so as to reduce the risk of the protruding structure piercing the adjacent diaphragm, thereby reducing the risk of short circuit of adjacent pole pieces and improving the safety and stability of the battery monomer.

[0106] The battery monomer disclosed in the embodiments of the present application can be used in a power consumption device using a battery device as a power supply or a variety of energy storage systems using a battery device as an energy storage element. The power consumption device can be, but is not limited to, a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, an electric vehicle, an electric car, a ship, a spacecraft, etc. Among them, the electric toy can include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric plane toy, etc., and the spacecraft can include an airplane, a rocket, a space shuttle, a spacecraft, etc.

[0107] The following embodiments are described by taking a power consumption device as a vehicle in an embodiment of the present application as an example for convenience of description.

[0108] Referring to FIG. 1, FIG. 1 is a structural schematic diagram of a power consumption device as a vehicle according to some embodiments of the present application. The vehicle can be a fuel automobile, a gas automobile, or a new energy automobile, and the new energy automobile can be a pure electric automobile, a hybrid electric automobile, or a range extended automobile, etc. The vehicle is internally provided with a battery device 1000, which can be arranged at the bottom, the head, or the tail of the vehicle. The battery device 1000 can be used for power supply of the vehicle, for example, the battery device 1000 can be used as an operating power supply of the vehicle. The vehicle can further include a controller 3000 and a motor 2000, and the controller 3000 is used to control the battery device 1000 to supply power to the motor 2000, for example, to meet the working power demand of the vehicle during starting, navigation, and driving.

[0109] In some embodiments of the present application, the battery device 1000 can not only be used as an operating power supply of the vehicle, but also be used as a driving power supply of the vehicle, to replace or partially replace fuel or natural gas to provide driving power for the vehicle.

[0110] Referring to FIG. 2, FIG. 2 is an exploded structural schematic diagram of a battery device 1000 according to some embodiments of the present application. The battery device 1000 includes a box 200 and a battery cell 100, and the battery cell 100 is accommodated in the box 200. The box 200 is used to provide an accommodation space for the battery cell 100, and the box 200 can adopt various structures. In some embodiments, the box 200 can include an upper box 201 and a lower box 202, and the upper box 201 and the lower box 202 are mutually covered to jointly define an accommodation space for accommodating the battery cell 100. The lower box 202 can be a hollow structure with one end open, and the upper box 201 can be a plate-shaped structure, and the upper box 201 covers the open side of the lower box 202 to jointly define the accommodation space with the lower box 202. The upper box 201 and the lower box 202 can also be hollow structures with one side open, and the open side of the upper box 201 covers the open side of the lower box 202. Of course, the box 200 formed by the upper box 201 and the lower box 202 can have various shapes, such as a cylinder, a cuboid, etc.

[0111] In the battery device 1000, the battery cell 100 can be multiple, and the multiple battery cells 100 can be connected in series, in parallel, or in a mixed connection. The mixed connection means that the multiple battery cells 100 are connected in series and in parallel. The multiple battery cells 100 can be directly connected in series, in parallel, or in a mixed connection, and then the whole of the multiple battery cells 100 is accommodated in the box 200. Of course, the battery device 1000 can also be that the multiple battery cells 100 are first connected in series, in parallel, or in a mixed connection to form a battery module, and then the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and the whole is accommodated in the box 200. The battery device 1000 can also include other structures, for example, the battery device 1000 can also include a current collecting component for realizing the electrical connection between the multiple battery cells 100.

[0112] Each battery cell 100 can be a secondary battery or a primary battery, and can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 100 can have a cylindrical shape, a flat shape, a cuboid shape, or other shapes, etc.

[0113] Referring to FIG. 3, the battery cell 100 refers to the smallest unit that constitutes the battery device 1000. The battery cell 100 includes an end cover 30, a case 20, an electrode assembly 10, and other functional components.

[0114] The end cover 30 refers to a component that covers the opening of the shell 20 to isolate the internal environment of the battery cell 100 from the external environment. Without limitation, the shape of the end cover 30 can be adapted to the shape of the shell 20 to fit the shell 20. Optionally, the end cover 30 can be made of a material with certain hardness and strength, such as aluminum alloy, so that the end cover 30 is not easily deformed when subjected to extrusion collision, so that the battery cell 100 can have higher structural strength, and the safety performance can also be improved. The end cover 30 can be provided with functional components such as electrode terminals 40. The electrode terminals 40 can be used to electrically connect with the electrode assembly 10 for outputting or inputting the electrical energy of the battery cell 100. In some embodiments, the end cover 30 can also be provided with a pressure relief mechanism for relieving the internal pressure of the battery cell 100 when the internal pressure or temperature of the battery cell 100 reaches a threshold value. The material of the end cover 30 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not make special limitations. In some embodiments, an insulating member can also be provided on the inner side of the end cover 30, which can be used to isolate the electrical connection part 1112c in the shell 20 from the end cover 30 to reduce the risk of short circuit. Exemplarily, the insulating member can be plastic, rubber, etc.

[0115] The shell 20 is a component for fitting the end cover 30 to form the internal environment of the battery cell 100, wherein the formed internal environment can be used to accommodate the electrode assembly 10, the electrolyte and other components. The shell 20 and the end cover 30 can be independent components, and an opening can be provided on the shell 20, and the end cover 30 is covered on the opening to form the internal environment of the battery cell 100. Without limitation, the end cover 30 and the shell 20 can also be integrated, specifically, the end cover 30 and the shell 20 can form a common connecting surface before other components enter the shell, and when it is necessary to encapsulate the internal environment of the shell 20, the end cover 30 is covered on the shell 20. The shell 20 can be various shapes and various sizes, such as cuboid, cylinder, hexagonal prism, etc. Specifically, the shape of the shell 20 can be determined according to the specific shape and size of the electrode assembly 10. The material of the shell 20 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not make special limitations.

[0116] The electrode assembly 10 is a component in which electrochemical reactions occur in the battery cell 100. One or more electrode assemblies 10 can be contained within the case 20. The electrode assembly 10 is mainly formed by winding or layering a positive electrode sheet 114 and a negative electrode sheet 115, and a separator 12 is generally provided between the positive electrode sheet 114 and the negative electrode sheet 115. The positive electrode sheet 114 and the negative electrode sheet 115 have portions with active materials that constitute the main body of the electrode assembly 10, and portions without active materials that each constitute a tab. The positive and negative tabs can be located together at one end of the main body or at separate ends of the main body. During charging and discharging of the battery device 1000, the positive and negative active materials react with the electrolyte, and the tabs connect the electrode terminals 40 to form a current loop.

[0117] In a first aspect, with reference to FIGS. 4-7, the embodiments of the present application provide a battery cell 100, comprising an electrode sheet 11, the electrode sheet 11 comprising a current collector 111 and an insulating layer 112. The current collector 111 comprises two end faces 1111a located at opposite ends along the width direction of the current collector 111, and the current collector 111 further comprises two side faces 1111b located at opposite sides along the thickness direction of the current collector 111, and the end face 1111a is formed with a protruding structure 1112; the insulating layer 112 is provided on the current collector 111, and the insulating layer 112 covers at least the end face 1111a and the protruding structure 1112.

[0118] In the drawings, the direction in which the X-axis lies is the length direction of the electrode sheet 11 and the length direction of the current collector 111; the direction in which the Y-axis lies is the width direction of the electrode sheet 11 and the width direction of the current collector 111; and the direction in which the Z-axis lies is the thickness direction of the electrode sheet 11 and the thickness direction of the current collector 111.

[0119] The current collector 111 refers to a structure in the electrode sheet 11 that is mainly used to support current flow. The main function of the current collector 111 is to provide an ion conductor in an electrochemical reaction to support the flow of current and separate the chemical reactions between the positive and negative electrodes, so that electrons flow in an external circuit to generate electrical energy. In a lithium ion battery, for example, the current collector 111 can be a copper foil, an aluminum foil, or a structural member of other materials.

[0120] The current collector 111 comprises the end face 1111a and the side face 1111b. The end face 1111a refers to two faces of the current collector 111 located at opposite ends along the width direction Y, and the end face 1111a is also the face formed after the electrode sheet 11 is slit, and burrs are usually formed on the end face 1111a. The side face 1111b refers to two faces of the current collector 111 located at opposite sides along the thickness direction Z, and active materials are usually formed on the side face 1111b.

[0121] The end surface 1111a of the current collector 111 is further provided with a protruding structure 1112. The protruding structure 1112 refers to a structure formed on the current collector 111 in the die cutting process of the pole piece 11. The die cutting of the pole piece 11 refers to a technology of cutting and forming the pole piece 11 by using a die. 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 die through extrusion, friction, cutting and the like.

[0122] The protruding structure 1112 is formed on the end surface 1111a. The protruding structure 1112 can be formed on the end surface 1111a by adjusting the die cutting direction and angle of the die. The protruding structure 1112 is a structure (for example, burr) extending outward from the end surface 1111a and protruding from the current collector 111. The protruding structure 1112 can be a regular shape or an irregular shape. The protruding structure 1112 can be a sharp shape, a semicircular shape, a wavy shape or other shapes. The protruding structure 1112 can include one or more parts protruding from the end surface 1111a. According to the forming process of the protruding structure 1112, the material of the protruding structure 1112 is the same as that of the current collector 111.

[0123] The insulating layer 112 refers to a layered structure in the pole piece 11 mainly used for protecting the end surface 1111a of the pole piece 11. The insulating layer 112 covers the end surface 1111a of the current collector 111. The insulating layer 112 can cover only one end surface 1111a, or can be divided into two or more parts and cover two end surfaces 1111a respectively. The insulating layer 112 can cover only the end surface 1111a, or can cover part of the end surface 1111a and the adjacent side surface 1111b. According to the material of the insulating layer 112, the insulating layer 112 can be connected to the end surface 1111a and / or the side surface 1111b by adhesion, welding or other means. The insulating layer 112 can also be a U-shaped, L-shaped or other shaped structure.

[0124] The insulating layer 112 covers the corresponding end surface 1111a and also covers the protruding structure 1112 on the corresponding end surface 1111a, so as to wrap the protruding structure 1112 inside the insulating layer 112.

[0125] Since the protruding structure 1112 is usually a structure with small size, the protruding structure 1112 is easy to swing and deform under the influence of the external environment (for example, shaking of the battery monomer 100, stirring of the electrolyte and the like), and is easy to pierce the adjacent diaphragm 12 and lap on the adjacent another pole piece 11 in the process of swinging and deforming, thereby causing short circuit of the adjacent two pole pieces 11.

[0126] Under the coverage of the insulating layer 112, the insulating layer 112 can separate the protruding structure 1112 from the external environment, the protruding structure 1112 is not easy to pierce the insulating layer 112, so that the protruding structure 1112 is not easy to be connected with other adjacent pole pieces 11, and the protruding structure 1112 is not easy to be 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.

[0127] In the embodiment, the end surface 1111a of the current collector 111 is formed with a protruding structure 1112, the protruding structure 1112 is easy to pierce the diaphragm 12 adjacent to the pole piece 11 and cause short circuit between the adjacent two pole pieces 11, thereby causing short circuit of the battery monomer 100; accordingly, the insulating layer 112 is arranged, 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, so as to reduce the risk of the protruding structure 1112 piercing the adjacent diaphragm 12, thereby being able to reduce the risk of short circuit between the adjacent pole pieces 11, and being able to improve the safety and stability of the battery monomer 100.

[0128] Referring to FIGS. 5, 9 and 10, in some embodiments, the insulating layer 112 wraps the protruding structure 1112.

[0129] The insulating layer 112 wraps the protruding structure 1112, that is, at least part 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, the protruding structure 1112 is not easy to swing to the direction of the diaphragm 12 and pierce the diaphragm 12, thereby being able to reduce the risk of the protruding structure 1112 piercing the diaphragm 12.

[0130] For example, the thickness of the insulating layer 112 can be greater than the length of the protruding structure 1112, wherein the length of the protruding structure 1112 refers to the length extending out of the current collector 111, at this time the insulating layer 112 can wrap the protruding structure 1112, and the protruding structure 1112 is difficult to pierce the insulating layer 112.

[0131] In the case that the insulating layer 112 wraps the protruding structure 1112, the protruding structure 1112 can not be deformed, at this time the insulating layer 112 can also fix the protruding structure 1112.

[0132] In the case that the insulating layer 112 wraps the protruding structure 1112, the protruding structure 1112 can also be deformed, the insulating layer 112 can press the protruding structure 1112 on the corresponding end surface 1111a, and the insulating layer 112 can also be folded to clamp the protruding structure 1112, and thus 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 toward the direction in which the diaphragm 12 is located, thereby reducing the risk of the protruding structure 1112 piercing the diaphragm 12.

[0133] For example, the insulating layer 112 can be folded on the end surface 1111a and clamp the protruding structure 1112 through the folded insulating layer 112; at this time, the folded insulating layer 112 can guide the extension direction of the protruding structure 1112, and thus make it difficult for the protruding structure 1112 to swing toward the direction in which the diaphragm 12 is located; for example, the insulating layer 112 can also bend the protruding structure 1112 toward the direction in which the corresponding end surface 1111a is located, so as to press or fix the protruding structure 1112 on the corresponding end surface 1111a.

[0134] In the technical scheme of the 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, and the insulating layer 112 wrapping the protruding structure 1112 can also fix 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.

[0135] Referring to FIGS. 4-6 and 9, in some embodiments, the thickness of the insulating layer 112 ranges from 9 μm to 30 μm.

[0136] The thickness of the insulating layer 112 reflects the strength of the insulating layer 112; the greater the thickness of the insulating layer 112, the greater the resistance of the protruding structure 1112 to pierce the insulating layer 112, and the better the restraining effect of the insulating layer 112 on the protruding structure 1112; referring to FIG. 5, in the case that part of the insulating layer 112 is connected to the side surface 1111b, the thickness of the insulating layer 112 can be the dimension of the part of the insulating layer 112 connected to the side surface 1111b in the thickness direction Z of the current collector 111, that is, the dimension W shown in the figure.

[0137] Since the arrangement of the insulating layer 112 will occupy the internal space of the shell 20, and the space occupation of 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 30 μm; 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 monomer 100.

[0138] The thickness of the insulation layer 112 ranges from 9 μm to 30 μm. In the case that the thickness of the insulation layer 112 is uniform or substantially uniform, the thickness of the insulation layer 112 refers to the thickness dimension of the insulation layer 112 at any part, which ranges from 9 μm to 30 μm. In the case that the thickness of the insulation layer 112 is not uniform, the minimum thickness of the insulation layer 112 should be greater than or equal to 9 μm, and the maximum thickness of the insulation layer 112 should be less than or equal to 30 μm.

[0139] The thickness of the insulation layer 112 ranges from 9 μm to 30 μm. In the case that the thickness of the insulation layer 112 is uniform or substantially uniform, the thickness of the insulation layer 112 refers to the thickness dimension of the insulation layer 112 at any part, which ranges from 9 μm to 30 μm. In the case that the thickness of the insulation layer 112 is not uniform, the minimum thickness of the insulation layer 112 should be greater than or equal to 9 μm, and the maximum thickness of the insulation layer 112 should be less than or equal to 30 μm.

[0140] For example, the thickness of the insulation layer 112 is 9 μm. In this case, the insulation 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 insulation layer 112 and extend outside the insulation layer 112. At the same time, this setting can also reduce the space occupation of the insulation layer 112 and reduce the negative impact of the insulation layer 112 on the energy density of the battery monomer 100.

[0141] For example, the thickness of the insulation layer 112 is 19.5 μm. In this case, the insulation layer 112 can better cover the protruding structure 1112, and the insulation layer 112 also has a higher strength, so that the protruding structure 1112 is difficult to pierce the insulation layer 112 and extend outside the insulation layer 112. The insulation layer 112 can also reduce the negative impact on the energy density of the battery monomer 100.

[0142] For example, the thickness of the insulation layer 112 is 30 μm. In this case, the insulation layer 112 can better cover the protruding structure 1112 and has a higher strength, so that the protruding structure 1112 is difficult to pierce the insulation layer 112 and extend outside the insulation layer 112, thereby improving the stability and safety of the battery monomer 100.

[0143] The thickness of the insulating layer 112 is greater than or equal to 9 μm, and after the insulating layer 112 covers the protruding structure 1112, the insulating layer 112 with the 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 the adjacent pole piece 11, and improving the safety and stability of the battery monomer 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, the thickness of the insulating layer 112 is limited 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 monomer 100.

[0144] In some embodiments, the needle penetration strength of the insulating layer 112 is greater than or equal to 300 gf (gram force).

[0145] The needle penetration strength of the insulating layer 112 refers to the load-carrying capacity or the ability to resist puncture damage of the insulating layer 112 under the action of needle penetration. The needle penetration strength of the insulating layer 112 reflects the ability of the insulating layer 112 to resist the piercing of the protruding structure 1112, and also reflects the protection ability of the insulating layer 112 to the current collector 111. The needle penetration strength of the insulating layer 112 is greater than or equal to 300 gf. For example, the needle penetration strength can be 300 gf, 500 gf, 800 gf, 1000 gf or other values.

[0146] 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 needle penetration 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.

[0147] For example, the needle penetration strength of the insulating layer 112 can be 300 gf, so that 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 short-circuiting of the pole piece 11 caused by the protruding structure 1112 piercing the diaphragm 12. At the same time, the requirement for the material of the insulating layer 112 is not too high, thereby reducing the processing cost and processing difficulty of the insulating layer 112.

[0148] For testing the needle penetration strength of the insulating layer 112, a steel needle can be used to test on a puncture tester, and the force at which the steel needle pierces the insulating layer 112 at a certain speed is recorded.

[0149] In an example, the insulating layer 112 is an insulating adhesive tape with a thickness of 13 μm, a length and a width of 50 mm; a steel needle with a diameter of 1 mm is used to perform the test on the puncture tester, and the force at which the insulating adhesive tape is punctured at a speed of 50 mm / min is recorded; in the case where the base layer 1121d of the insulating adhesive tape is polypropylene with a thickness of 10 μm and the adhesive layer 1121e is polyacrylate with a thickness of 3 μm, puncture tests are performed on ten insulating adhesive tapes of the same specification, and the average pre-puncture degree of the insulating adhesive tape is 425.31 gf.

[0150] The present embodiment provides a range of puncture strengths of the insulating layer 112, so that the burr is difficult to puncture the insulating layer 112, thereby enabling the insulating layer 112 to better reduce the risk of short circuiting of the burr and the adjacent pole piece 11.

[0151] Referring to FIGS. 6 and 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 face 1111a; and the insulating layer 112 covers the first protruding portions 1112a.

[0152] The first protruding portion 1112a refers to a structure in the protruding structure 1112; the shape of the first protruding portion 1112a can be a regular shape or an irregular shape, and the shape of the first protruding portion 1112a can be a sharp shape, a semicircular shape, a wavy shape, or other shapes; since the first protruding portion 1112a is a structure formed by extrusion, friction, cutting, or the like between the current collector 111 and the mold, the shape of the first protruding portion 1112a is usually irregular.

[0153] The number of first protruding portions 1112a can be two, three, or more; the plurality of first protruding portions 1112a are spaced apart along the length direction of the current collector 111, and there is a gap between adjacent two first protruding portions 1112a; since the first protruding portion 1112a is a structure formed by extrusion, friction, cutting, or the like between the current collector 111 and the mold, the spacing of the first protruding portion 1112a is positively correlated with the movement period of the mold.

[0154] Since the first protruding portions 1112a are spaced apart from each other, the first protruding portions 1112a are single independent structures in the protruding structure 1112, and each first protruding portion 1112a is independent and not connected to each other.

[0155] The first protruding portion 1112a is formed on the end face 1111a, which can be achieved by adjusting the die cutting direction and angle of the mold; at this time, the position of the first protruding portion 1112a is relatively fixed, so as to facilitate the arrangement of the insulating layer 112 and the covering of each first protruding portion 1112a.

[0156] The insulating layer 112 covers the first protruding part 1112a, so that the first protruding part 1112a is less likely to pierce the insulating layer 112, and thus less likely to pierce the adjacent diaphragm 12 and short with the adjacent other pole piece 11. The insulating layer 112 can press the first protruding part 1112a on the end face 1111a to fix the first protruding part 1112a and reduce the risk of the first protruding part 1112a piercing the insulating layer 112; the insulating layer 112 can also be folded at the end face 1111a and clamps the first protruding part 1112a at the folded part to guide the extending direction of the first protruding part 1112a, so that the first protruding part 1112a is less likely to bend towards the direction of the adjacent diaphragm 12, thus reducing the risk of the first protruding part 1112a piercing the adjacent diaphragm 12; the insulating layer 112 can also completely wrap the first protruding part 1112a to fix the first protruding part 1112a, and under the wrapping of the insulating layer 112, the first protruding part 1112a is less likely to pierce the diaphragm 12 even if it bends towards the direction of the diaphragm 12, thus reducing the risk of the first protruding part 1112a piercing the diaphragm 12 and shorting with the adjacent other pole piece 11; it can be understood that the insulating layer 112 can cover the first protruding part 1112a in other ways, not limited to the above.

[0157] The embodiments provide specific structures of the protruding structure 1112, so that the protruding structure 1112 includes the first protruding part 1112a arranged at intervals, and the insulating layer 112 can cover the first protruding part 1112a, so that the insulating layer 112 can adapt to the structure of the first protruding part 1112a.

[0158] Referring to FIGS. 6 and 7, in some embodiments, the length of the first protruding part 1112a ranges from 40 μm to 200 μm.

[0159] The length of the first protruding part 1112a refers to the length of the first protruding part 1112a extending out of the current collector 111, and the length of the first protruding part 1112a also represents the maximum thickness of the diaphragm 12 that can be pierced by the first protruding part 1112a, i.e., in the case that the maximum thickness of the diaphragm 12 is less than the length of the first protruding part 1112a, the first protruding part 1112a can pierce the diaphragm 12.

[0160] For example, referring to FIG. 7, in the case that the first protruding part 1112a extends away from the current collector 111 along the width direction Y of the current collector 111 from the end face 1111a, the length of the first protruding part 1112a is the dimension of the first protruding part 1112a in the width direction Y of the current collector 111.

[0161] The length of the first protruding part 1112a ranges from 40 μm to 200 μm. For example, the length of the first protruding part 1112a can be 40 μm, 40 μm, 60 μm, 80 μm, 100 μm, 120 μm, 140 μm, 160 μm, 180 μm, 200 μm or other values. The length of the first protruding part 1112a can be adjusted by adjusting the mold or adjusting the cutting speed. However, due to the limitation of machining precision, the length of the first protruding part 1112a is difficult to be less than 40 μm.

[0162] For example, the length of the first protruding part 1112a can be 40 μm. At this time, the length of the first protruding part 1112a is small, and accordingly, the thickness of the insulating layer 112 can also be small. Under the premise that the insulating layer 112 can cover the first protruding part 1112a, this setting can better reduce the space occupation of the first protruding part 1112a and the insulating layer 112, and better reduce the negative impact of the insulating layer 112 on the energy density of the battery monomer 100.

[0163] For example, the length of the first protruding part 1112a can be 120 μm. At this time, the length of the first protruding part 1112a is large, and accordingly, the thickness of the insulating layer 112 can also be large. In this way, the insulating layer 112 can not only cover the first protruding part 1112a to reduce the risk of the first protruding part 1112a piercing the diaphragm 12, but also reduce the space occupation of the insulating layer 112 and reduce the negative impact of the insulating layer 112 on the energy density of the battery monomer 100.

[0164] For example, the length of the first protruding part 1112a can be 200 μm. At this time, the length of the first protruding part 1112a is larger, and accordingly, the thickness of the insulating layer 112 can also be larger. In this way, the insulating layer 112 can better cover the first protruding part 1112a, so that the first protruding part 1112a is difficult to pierce the diaphragm 12 and short-circuit with the adjacent pole piece 11.

[0165] The embodiment provides a size range of some first protruding parts 1112a, and the insulating layer 112 can adapt to the structure of the first protruding part 1112a, so that the insulating layer 112 can cover first protruding parts 1112a of different sizes, thereby making protruding structures 1112 of different sizes difficult to pierce the insulating layer 112.

[0166] Referring to FIGS. 6 and 7, in some embodiments, in the length direction of the current collector 111, the number of first protruding parts 1112a with a size range of 1 mm is greater than or equal to 1; and the thickness of the insulating layer 112 ranges from 13 μm to 30 μm.

[0167] The number of the first protrusions 1112a in the 1mm size range in the length direction X of the current collector 111 represents the density of the first protrusions 1112a, and the number of the first protrusions 1112a in the 1mm size range is greater than or equal to 1, that is, the number of the first protrusions 1112a in the 1mm size range can be one or two or more; the more the number of the first protrusions 1112a in the 1mm size range, the higher the risk that one or more of the plurality of first protrusions 1112a pierces the insulating layer 112 and pierces the diaphragm 12.

[0168] Accordingly, the thickness of the insulating layer 112 is in the range of 13μm-30μm, that is, the thickness of the insulating layer 112 is relatively thick, so that the insulating layer 112 can have higher strength, so that the insulating layer 112 can better cover and fix the first protrusions 1112a, and reduce the risk that the first protrusions 1112a pierce the insulating layer 112 and pierce the diaphragm 12.

[0169] The thickness of the insulating layer 112 can be 13μm, 16μm, 19μm, 22μm, 25μm, 27μm, 30μm or other values.

[0170] For example, the thickness of the insulating layer 112 is 13μm, which can reduce the space occupation of the insulating layer 112 and reduce the negative impact of the insulating layer 112 on the energy density of the battery monomer 100 on the premise that the insulating layer 112 can cover and fix the first protrusions 1112a.

[0171] For example, the thickness of the insulating layer 112 is 21.5μm, at which the insulating layer 112 can better cover and fix the first protrusions 1112a, so that the first protrusions 1112a are 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 monomer 100.

[0172] For example, the thickness of the insulating layer 112 is 30μm, at which 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 monomer 100.

[0173] The embodiment provides some arrangement structures of the first protrusions 1112a and specific thickness ranges of the corresponding insulating layer 112, so that the insulating layer 112 can better adapt to the size and arrangement structure of the first protrusions 1112a, so that the insulating layer 112 can better cover and fix the first protrusions 1112a, and the first protrusions 1112a are difficult to pierce the insulating layer 112.

[0174] Referring to FIGS. 6 and 7, in some embodiments, the protruding structure 1112 further comprises a plurality of second protruding portions 1112b arranged at intervals along the length direction of the current collector 111, and a connecting portion 1112c is arranged between any two adjacent second protruding portions 1112b, and the connecting portion 1112c and the second protruding portion 1112b are both formed on the end face 1111a; the length of the connecting portion 1112c is less than the length of the second protruding portion 1112b; and the insulating layer 112 covers the second protruding portion 1112b and the connecting portion 1112c.

[0175] The second protruding portion 1112b refers to a structure of the protruding structure 1112; the shape of the second protruding portion 1112b can be a regular shape or an irregular shape, and the shape of the second protruding portion 1112b can be a sharp shape, a semicircular shape, a wavy shape or other shapes; since the second protruding portion 1112b is a structure formed by extrusion, friction, cutting and the like between the current collector 111 and the mold, the shape of the second protruding portion 1112b is usually irregular; the number of the second protruding portion 1112b can be two, or three or more; a plurality of second protruding portions 1112b are arranged at intervals along the length direction of the current collector 111, and there is a gap between any two adjacent second protruding portions 1112b.

[0176] The connecting portion 1112c refers to a structure of the protruding structure 1112; since there is a gap between any two adjacent second protruding portions 1112b, the connecting portion 1112c is formed between any two adjacent second protruding portions 1112b and connected to the 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 by extrusion, friction, cutting and the like between the current collector 111 and the mold, the number, interval and arrangement of the second protruding portion 1112b in a single continuous structure are positively correlated with the movement period of the mold.

[0177] The protruding structure 1112 can include only one such continuous structure, or two or more such continuous structures; since the continuous structure is a structure formed by extrusion, friction, cutting and the like between the current collector 111 and the mold, the number, interval and arrangement of the continuous structure are positively correlated with the movement period of the mold;

[0178] The second protruding portion 1112b and the connecting portion 1112c are both formed on the end face 1111a, and the second protruding portion 1112b and the connecting portion 1112c can be formed on the end face 1111a by adjusting the die cutting direction and angle of the mold; at this time, the positions of the second protruding portion 1112b and the connecting portion 1112c are relatively fixed, so as to facilitate the arrangement of the insulating layer 112 and the covering of each second protruding portion 1112b and each connecting portion 1112c.

[0179] The length of the connecting portion 1112c refers to the length of the connecting portion 1112c extending out of the current collector 111; with reference to FIG. 7, in the case where the connecting portion 1112c extends away from the current collector 111 along the width direction Y of the current collector 111 from the end surface 1111a, the length of the connecting portion 1112c also refers to the dimension of the connecting portion 1112c in the width direction Y of the current collector 111.

[0180] Similarly to the connecting portion 1112c, the length of the second protruding portion 1112b refers to the length of the second protruding portion 1112b extending out of the current collector 111; with reference to FIG. 7, in the case where the second protruding portion 1112b extends away from the current collector 111 along the width direction Y of the current collector 111 from the end surface 1111a, the length of the second protruding portion 1112b also refers to the dimension of the second protruding portion 1112b in the width direction Y of the current collector 111.

[0181] The length of the connecting portion 1112c is less than the length of the second protruding portion 1112b, i.e., in the continuous structure formed by the second protruding portion 1112b and the connecting portion 1112c, the second protruding portion 1112b is more likely to pierce the adjacent separator 12 and short-circuit with the adjacent another pole piece 11; accordingly, the insulation layer 112 should be arranged according to the size of the second protruding portion 1112b, and in the case where the insulation layer 112 can reduce the risk of the second protruding portion 1112b piercing the separator 12, the connecting portion 1112c is more difficult to pierce the separator 12.

[0182] The insulation layer 112 covers the second protruding portion 1112b, so that the second protruding portion 1112b is less likely to pierce the insulation layer 112, thereby making it difficult for the second protruding portion 1112b to pierce the adjacent separator 12 and short-circuit with the adjacent another pole piece 11; since the length of the connecting portion 1112c is less than the length of the second protruding portion 1112b, the connecting portion 1112c is more difficult to pierce the adjacent separator 12.

[0183] The insulating layer 112 can press the second protruding portion 1112b and the connecting portion 1112c on the end surface 1111a to fix the second protruding portion 1112b and the connecting portion 1112c and reduce the risk of the second protruding portion 1112b piercing the insulating layer 112; the insulating layer 112 can also be folded at the end surface 1111a and clamp the second protruding portion 1112b and the connecting portion 1112c at the folded portion to guide the extension direction of the second protruding portion 1112b and the connecting portion 1112c, so that the second protruding portion 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 protruding portion 1112b piercing the adjacent diaphragm 12; the insulating layer 112 can also completely wrap the second protruding portion 1112b and the connecting portion 1112c to fix the second protruding portion 1112b and the connecting portion 1112c, and under the wrapping of the insulating layer 112, even if the second protruding portion 1112b bends in the direction of the diaphragm 12, it is difficult to pierce the diaphragm 12, thereby reducing the risk of the second protruding portion 1112b piercing the diaphragm 12 and short-circuiting with the adjacent another pole piece 11; it can be understood that the insulating layer 112 can also cover the second protruding portion 1112b in other ways, not limited to the above several.

[0184] The embodiment provides specific structures of the other protruding structures 1112, so that the protruding structure 1112 includes the second protruding portion 1112b arranged at intervals, and the connecting portion 1112c is arranged between adjacent second protruding portions 1112b; and the insulating layer 112 can cover the second protruding portion 1112b, so that the insulating layer 112 can adapt to the structure of the second protruding portion 1112b.

[0185] Referring to FIGS. 6 and 7, in some embodiments, the length of the second protruding portion 1112b ranges from 15 μm to 40 μm.

[0186] The length of the second protruding portion 1112b refers to the length of the second protruding portion 1112b extending out of the current collector 111; that is, in the case that the maximum thickness of the diaphragm 12 is less than the length of the second protruding portion 1112b, the second protruding portion 1112b can pierce the diaphragm 12.

[0187] For example, referring to FIG. 7, in the case that the second protruding portion 1112b extends away from the current collector 111 along the width direction of the current collector 111 from the end surface 1111a, the length of the second protruding portion 1112b is the dimension Y of the second protruding portion 1112b in the width direction of the current collector 111.

[0188] The length of the second protruding part 1112b ranges from 15 μm to 40 μm. For example, the length of the second protruding part 1112b can be 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, or any other value. The length of the second protruding part 1112b can be adjusted by adjusting the mold or the cutting speed. However, due to the limitation of the machining precision, the length of the second protruding part 1112b is difficult to be less than 15 μm.

[0189] For example, the length of the second protruding part 1112b can be 15 μm. In this case, the length of the second protruding part 1112b is relatively small, and accordingly, the thickness of the insulating layer 112 can also be relatively small. Under the premise that the insulating layer 112 can cover and fix the second protruding part 1112b, this arrangement can better reduce the spatial occupation of the second protruding part 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.

[0190] For example, the length of the second protruding part 1112b can be 27.5 μm. In this case, the length of the second protruding part 1112b is relatively large, and accordingly, the thickness of the insulating layer 112 can also be relatively large. In this way, the insulating layer 112 can not only cover and fix the second protruding part 1112b to reduce the risk of the second protruding part 1112b piercing the diaphragm 12, but also reduce the spatial occupation of the insulating layer 112 and the negative impact of the insulating layer 112 on the energy density of the battery cell 100.

[0191] For example, the length of the second protruding part 1112b can be 40 μm. In this case, the length of the second protruding part 1112b is larger, and accordingly, the thickness of the insulating layer 112 can also be larger. In this way, the insulating layer 112 can better cover and fix the second protruding part 1112b, so that the second protruding part 1112b is difficult to pierce the diaphragm 12 and short-circuit with the adjacent pole piece 11.

[0192] It can be understood that, depending on the processing technology, the current collector 111 can only have the first protruding part 1112a or the second protruding part 1112b, or can have both the first protruding part 1112a and the second protruding part 1112b. In the case where the current collector 111 has both the first protruding part 1112a and the second protruding part 1112b, according to the length range of the first protruding part 1112a and the length range of the second protruding part 1112b, the length of the first protruding part 1112a is greater than or equal to the length of the second protruding part 1112b. In this case, under the condition that the insulating layer 112 can cover and fix the first protruding part 1112a to reduce the risk of the first protruding part 1112a piercing the diaphragm 12, the insulating layer 112 can also cover and fix the second protruding part 1112b to reduce the risk of the second protruding part 1112b piercing the diaphragm 12.

[0193] The embodiment provides a size range of some 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, so that protrusion structures 1112 of different sizes are all difficult to pierce the insulating layer 112.

[0194] Referring to FIGS. 6 and 7, in some embodiments, in the length direction of the current collector 111, the number of second protrusions 1112b in the size range of 1 mm is 3-5; the thickness of the insulating layer 112 is 9-13 μm.

[0195] The number of second protrusions 1112b in the size range of 1 mm in the length direction X of the current collector 111 represents the density of the second protrusions 1112b, and the number of second protrusions 1112b in the size range of 1 mm is 3-5, that is, the number of second protrusions 1112b in the size range of 1 mm can be three, four, or five; the more the number of second protrusions 1112b in the size range, the higher the risk that one or more of the plurality of second protrusions 1112b pierces the insulating layer 112 and the separator 12.

[0196] Because the length of the second protrusion 1112b is short, when the number of second protrusions 1112b in the size range of 1 mm is 3-5, the thickness of the insulating layer 112 is 9-13 μm, which can not only better cover and fix the second protrusions 1112b to reduce the risk that the second protrusions 1112b pierce the insulating layer 112 and the separator 12, but also reduce the space occupation of the insulating layer 112 and reduce the negative impact of the insulating layer 112 on the energy density of the battery monomer 100.

[0197] The thickness of the insulating layer 112 can be 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, or other values.

[0198] For example, the thickness of the insulating layer 112 is 9 μm, which can reduce the space occupation of the insulating layer 112 and reduce the negative impact of the insulating layer 112 on the energy density of the battery monomer 100, on the premise that the insulating layer 112 can cover and fix the second protrusions 1112b.

[0199] For example, the thickness of the insulating layer 112 is 11 μm, which can not only better cover and fix the second protrusions 1112b so that the second protrusions 1112b are difficult to pierce the insulating layer 112 and extend outside the insulating layer 112, but also reduce the negative impact on the energy density of the battery monomer 100.

[0200] For example, the thickness of the insulation layer 112 is 13 μm, and the insulation layer 112 can better cover and fix the second protruding part 1112b, so that the second protruding part 1112b is difficult to pierce the insulation layer 112 and extend out of the insulation layer 112, thereby improving the stability and safety of the battery monomer 100.

[0201] The embodiment provides the arrangement structure of some second protruding parts 1112b and the specific thickness range of the corresponding insulation layer 112, so that the insulation layer 112 can better adapt to the size and arrangement structure of the second protruding part 1112b, thereby making the insulation layer 112 better cover and fix the second protruding part 1112b, and making the second protruding part 1112b difficult to pierce the insulation layer 112.

[0202] Referring to FIGS. 6 and 7, in some embodiments, in the length direction of the current collector 111, the number of the second protruding parts 1112b in the size range of 1 mm is 5-15; and the thickness of the insulation layer 112 is 13 μm-30 μm.

[0203] The number of the second protruding parts 1112b in the size range of 1 mm in the length direction X of the current collector 111 can also be 5-15, that is, the number of the second protruding parts 1112b in the size range of 1 mm can be five, six, ten, fifteen or other numbers; the more the number of the second protruding parts 1112b in the size range, the higher the risk that one or more of the plurality of second protruding parts 1112b pierces the insulation layer 112 and the diaphragm 12.

[0204] When the number of the second protruding parts 1112b in the size range of 1 mm is 5-15, the number of the second protruding parts 1112b is large, and the risk that the second protruding part 1112b pierces the insulation layer 112 and the diaphragm 12 is high; accordingly, the thickness of the insulation layer 112 is 13 μm-30 μm, so that the insulation layer 112 has higher strength, thereby making the insulation layer 112 better cover and fix the second protruding part 1112b, and reducing the risk that the second protruding part 1112b pierces the insulation layer 112 and the diaphragm 12.

[0205] The thickness of the insulation layer 112 can be 13 μm, or 16 μm, 19 μm, 22 μm, 25 μm, 27 μm, 30 μm or other values.

[0206] For example, the thickness of the insulation layer 112 is 13 μm, and under the premise that the insulation layer 112 can cover and fix the second protruding part 1112b, this setting can reduce the space occupation of the insulation layer 112 and reduce the negative impact of the insulation layer 112 on the energy density of the battery monomer 100.

[0207] For example, the thickness of the insulation layer 112 is 21.5 μm, and in this case, the insulation layer 112 can better cover and fix the second protruding part 1112b, so that the second protruding part 1112b is difficult to pierce the insulation layer 112 and extend outside the insulation layer 112, and the insulation layer 112 can reduce the negative impact on the energy density of the battery monomer 100.

[0208] For example, the thickness of the insulation layer 112 is 30 μm, and in this case, the insulation layer 112 can better cover and fix the second protruding part 1112b, so that the second protruding part 1112b is difficult to pierce the insulation layer 112 and extend outside the insulation layer 112, thereby improving the stability and safety of the battery monomer 100.

[0209] The embodiment provides another arrangement structure of the second protruding part 1112b and a specific thickness range of the corresponding insulation layer 112, so that the insulation layer 112 can better adapt to the size and arrangement structure of the second protruding part 1112b, thereby making the insulation layer 112 better cover the second protruding part 1112b and making the second protruding part 1112b difficult to pierce the insulation layer 112.

[0210] Referring to FIGS. 6, 8-10, in some embodiments, the insulation layer 112 includes two sub-insulation layers 1121 corresponding to the two side surfaces 1111b, the sub-insulation layer 1121 includes a first part 1121a and a second part 1121b connected to the first part 1121a, and the second part 1121b is connected to the side surface 1111b; at least part of the first part 1121a is connected to the first part 1121a of the adjacent another sub-insulation layer 1121, and the two first parts 1121a cover the protruding structure 1112 to guide the protruding structure 1112 to extend along the width direction of the current collector 111.

[0211] The sub-insulation layer 1121 refers to a part of the insulation layer 112, and there are two sub-insulation layers 1121, and the two sub-insulation layers 1121 can be spliced to form the insulation layer 112; the two sub-insulation layers 1121 can be arranged on opposite sides of the current collector 111 and connected at the end surface 1111a of the current collector 111, so that the insulation layer 112 can cover the end surface 1111a and part of the side surface 1111b.

[0212] The sub-insulating layer 1121 includes a first part 1121a and a second part 1121b. The second part 1121b is a part of the sub-insulating layer 1121 and is connected to the side surface 1111b to fix the sub-insulating layer 1121. According to the material of the sub-insulating layer 1121, the second part 1121b can be bonded to the side surface 1111b or connected to the side surface 1111b by curing or the like. The first part 1121a is also a part of the sub-insulating layer 1121 and is connected to the second part 1121b. The first part 1121a can be integrally formed with the second part 1121b, or the first part 1121a can be connected to the second part 1121b by bonding, curing or the like.

[0213] Since the second part 1121b is connected to the side surface 1111b, the first part 1121a can extend outside the current collector 111. Since the insulating layer 112 is arranged on the side of the current collector 111 having the tab part 1113, at least part of the first part 1121a can be connected to the first part 1121a of another sub-insulating layer 1121 adjacent thereto. In this case, the first part 1121a capable of being connected to the other first part 1121a covers the corresponding end surface 1111a.

[0214] The first part 1121a can extend outside the current collector 111, and part of the two first parts 1121a can be connected to each other and hold the protruding structure 1112 between the two first parts 1121a. In this case, the two first parts 1121a can correct 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 substantially 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 the diaphragm 12 adjacent to the tab 11, thereby better reducing the risk of the protruding structure 1112 piercing the diaphragm 12 and short-circuiting with another tab 11.

[0215] The embodiment provides 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 the first part 1121a and the second part 1121b, and the two first parts 1121a hold the protruding structure 1112 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 less likely to bend to the two sides and pierce the sub-insulating layer 1121 or the diaphragm 12 adjacent thereto.

[0216] Referring to FIGS. 6, 8-10, in some embodiments, the current collector 111 includes a current collector body 1111 and tab portions 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 tab portions 1113 extend from either of the two end surfaces 1111a in a direction away from the current collector body 1111 along the width direction Y of the current collector 111.

[0217] The current collector body 1111 refers to a portion of the current collector 111 that is used to carry active materials; both the end surface 1111a and the side surface 1111b refer to surfaces on the current collector body 1111, that is, the end surface 1111a refers to two surfaces located at opposite ends of the current collector body 1111 along the width direction Y of the current collector 111, and the side surface 1111b refers to two surfaces located at opposite sides of the current collector body 1111 along the thickness direction Z of the current collector 111.

[0218] The tab portion 1113 refers to a portion of the current collector 111 that extends outward from the current collector body 1111, and the tab portion 1113 is used to make the tab 11 conductive with a circuit outside the electrode assembly 10; the tab portion 1113 can be integrally formed with the current collector body 1111, or can be connected to the current collector body 1111 by means of gluing, welding, etc.; there can be one, two, or more tab portions 1113.

[0219] The tab portion 1113 extends outward from either of the two end surfaces 1111a of the current collector body 1111, and the tab portion 1113 extends along the width direction Y of the current collector 111.

[0220] The tab portion 1113 is usually formed by a die-cutting process, at which time the protruding structure 1112 is formed on the end surface 1111a to which the tab portion 1113 is connected, and the insulating layer 112 also covers the end surface 1111a to which the tab portion 1113 is connected; in the case where the insulating layer 112 includes the first portion 1121a and the second portion 1121b, the first portion 1121a extends outward from the current collector 111 along the width direction Y of the current collector 111, at which time the first portion 1121a, in addition to being able to cover the corresponding end surface 1111a, is also able to cover at least a portion of the tab portion 1113 at a position on the corresponding end surface 1111a where the tab portion 1113 is present, the portion of the insulating layer 112 that covers the end surface 1111a is connected to another corresponding adjacent first portion 1121a, and the portion of the first portion 1121a that covers the tab portion 1113 is connected to the corresponding tab portion 1113.

[0221] Referring to FIGS. 6, 8-10, in some embodiments, the size of the first portion 1121a in the width direction of the current collector 111 ranges from 0.2 mm to 6 mm.

[0222] The size of the first portion 1121a in the width direction Y of the current collector 111 is the width size of the first portion 1121a, and the size indicated by L1 in FIGS. 8 to 10 is the size of the first portion 1121a in the width direction Y of the current collector 111. The size of the first portion 1121a in the width direction Y of the current collector 111 ranges from 0.2 mm to 6 mm, and for example, the size of the first portion 1121a in the width direction Y of the current collector 111 can be 0.2 mm, 1 mm, 1.8 mm, 2.6 mm, 2.9 mm, 3.4 mm, 4.2 mm, 5.1 mm, 6 mm, or other values.

[0223] Since the first portion 1121a is used to extend out of 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.

[0224] Since the first portion 1121a also covers part of the tab 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 conduction performance of the tab portion 1113. At the same time, affected by the energy density of the battery monomer 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 monomer 100.

[0225] For example, the size of the first portion 1121a in the width direction Y of the current collector 111 can be 0.2 mm, which can make the size of the first portion 1121a smaller under the premise that the first portion 1121a can cover the protruding structure 1112, so as to reduce the area of the first portion 1121a covering the tab portion 1113 and the space occupation of the first portion 1121a, thereby reducing the negative impact of the first portion 1121a on the conduction performance of the tab portion 1113 and the energy density of the battery monomer 100.

[0226] For example, the size of the first portion 1121a in the width direction Y of the current collector 111 can be 3.1 mm, which can make the first portion 1121a better cover the protruding structure 1112 to reduce the risk of the protruding structure 1112 piercing the adjacent separator 12, and can also reduce the area and space occupation of the first portion 1121a covering the tab portion 1113, thereby reducing the negative impact of the first portion 1121a on the conduction performance of the tab portion 1113 and the energy density of the battery monomer 100.

[0227] For example, the first part 1121a can have a size of 6 mm in the width direction Y of the current collector 111, so that the first part 1121a can better cover the protruding structure 1112 and reduce the risk of the protruding structure 1112 piercing the adjacent separator 12.

[0228] The embodiments provide some size ranges of the first part 1121a, so that the first part 1121a can better cover the protruding structure 1112 and reduce the risk of the protruding structure 1112 piercing the insulating layer 112, can reduce the occupation of the first part 1121a to the internal space of the battery cell 100, reduce the negative impact of the insulating layer 112 on the energy density of the battery cell 100, and can reduce the area of the first part 1121a covering the tab part 1113, and reduce the negative impact of the insulating layer 112 on the conduction performance of the tab part 1113.

[0229] Referring to FIGS. 6, 8-10, in some embodiments, the tab 11 further includes an active material layer 113 disposed on the side surface 1111b, the active material layer 113 covering at least part of the side surface 1111b, and the sub-insulating layer 1121 being connected to the active material layer 113.

[0230] The active material layer 113 refers to a layered structure formed on the side surface 1111b of the current collector 111 and used to participate in an electrochemical reaction. According to the polarity of the tab 11, the material of the active material layer 113 can include lithium manganate, lithium cobaltate, lithium nickel cobalt manganese oxide, etc., and the material of the active material layer 113 can also include natural graphite, artificial graphite, etc.

[0231] The active material layer 113 can cover only part of the side surface 1111b or cover the entire adjacent side surface 1111b. Since the area of the active material layer 113 is positively correlated with the charge and discharge performance of the tab 11, the active material layer 113 should cover as much of the corresponding side surface 1111b as possible, i.e., the active material layer 113 should cover most of the corresponding side surface 1111b or cover the entire corresponding side surface 1111b.

[0232] In the case where the active material layer 113 covers most of the corresponding side surface 1111b or covers the entire corresponding side surface 1111b, the area of the side surface 1111b not covered by the active material layer 113 is small, so that connecting the sub-insulating layer 1121 to the active material layer 113 can improve the connection stability of the sub-insulating layer 1121.

[0233] In the embodiments, 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 tab 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 falling of the insulating layer 112.

[0234] Referring to FIGS. 6, 8-10, in some embodiments, the active material layer 113 covers part of the side surface 1111b, and a blank area 1111c is formed on the side surface 1111b close to the end surface 1111a. The second part 1121b covers at least part of the blank area 1111c.

[0235] The blank area 1111c refers to an area on the side surface 1111b that is not covered by the active material layer 113, and the blank area 1111c is formed on the side surface 1111b and located on the side of the side surface 1111b close to the end surface 1111a. Referring to FIG. 9, the area corresponding to the dimension L4 is the blank area 1111c.

[0236] The second part 1121b covers at least part of the blank area 1111c, that is, the second part 1121b can completely cover the blank area 1111c, or can only cover part of the blank area 1111c. For example, the second part 1121b completely covers the blank area 1111c, and an end of the second part 1121b away from the first part 1121a is in contact with the active material layer 113.

[0237] The second part 1121b covering the blank area 1111c can reduce the area of the current collector 111 directly contacting the electrolyte, thereby reducing the damage of the electrolyte to the current collector 111 and reducing the occurrence of short circuit and other situations of the battery monomer 100.

[0238] In the present embodiment, the second part 1121b can cover at least part of the blank area 1111c to protect the current collector 111, and also reduce the area of the current collector 111 exposed to the outside, thereby reducing the occurrence of short circuit and other situations and improving the safety performance of the battery monomer 100.

[0239] Referring to FIGS. 6, 8-10, in some embodiments, in the width direction of the current collector 111, the size of the blank area 1111c is less than or equal to 5 mm.

[0240] 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 5 mm. For example, the size can be 5 mm, 4.5 mm, 4 mm, 3.5 mm, 3 mm, 2.5 mm, 2 mm, 1.5 mm, 1 mm, 0.5 mm, 0 mm, or other values.

[0241] It can be understood that, in the case that the size of the blank area 1111c in the current collector 111 width direction Y is 0, the active material layer 113 completely covers the corresponding side surface 1111b, and the blank area 1111c does not exist.

[0242] The area of the blank area 1111c is negatively correlated with the charge-discharge performance of the pole piece 11, that is, the size of the blank area 1111c in the current collector 111 width direction Y is negatively correlated with the charge-discharge performance of the pole piece 11, but the blank area 1111c is not easy to be completely eliminated due to the influence of the processing process, so the size of the blank area 1111c in the current collector 111 width direction Y should be as small as possible.

[0243] For example, the size of the blank area 1111c in the current collector 111 width direction Y is 5mm, at this time the charge-discharge performance of the pole piece 11 can meet the minimum requirement; 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.

[0244] For example, the size of the blank area 1111c in the current collector 111 width direction Y is 2.5mm, compared with the size of 5mm, at this time the charge-discharge performance of the pole piece 11 can be improved; at the same time, the current collector 111 also has a certain space for the second part 1121b to connect, so that the second part 1121b can be connected to the current collector 111.

[0245] For example, the size of the blank area 1111c in the current collector 111 width direction Y is 0, at this time the charge-discharge performance of the pole piece 11 can better meet the demand.

[0246] The 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, and at the same time, the negative influence of the blank area 1111c on the coverage area of the active material layer 113 can be reduced, so as to reduce the negative influence of the blank area 1111c on the charge-discharge capacity of the pole piece 11.

[0247] Referring to FIGS. 6, 8-10, in some embodiments, the sub-insulating layer 1121 further includes a third part 1121c connected to the second part 1121b and opposite to the first part 1121a, the second part 1121b covers the blank area 1111c, and the third part 1121c covers a part of the active material layer 113.

[0248] The third part 1121c is a part of the sub-insulating layer 1121, and is connected to 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 the width direction Y of the current collector 111 in sequence; the third part 1121c can be integrally formed with the second part 1121b, or can be connected to the second part 1121b by bonding, curing, or the like.

[0249] The third part 1121c is connected to the active material layer 113 and covers a part of the active material layer 113. Since the third part 1121c is connected to the second part 1121b, the second part 1121b can completely cover the blank area 1111c at this time, so as to better play a role in protecting the main body part 1131 and better improve the safety performance of the battery monomer 100.

[0250] According to the structure of the third part 1121c, the third part 1121c can be connected to the active material layer 113 by bonding, or can be connected to the active material layer 113 by curing or other means.

[0251] If the sub-insulating layer 1121 does not cover the active material layer 113, due to the influence of the processing process, the second part 1121b of the sub-insulating layer 1121 is difficult to seal and seamlessly contact the active material layer 113, and the gap between the second part 1121b and the active material layer 113 is easy to cause the main body part 1131 to be exposed and cause short circuit and other situations.

[0252] Accordingly, the sub-insulating layer 1121 further includes the third part 1121c, and the third part 1121c covers a part of the active material layer 113, so that the second part 1121b can completely cover the blank area 1111c, thereby further improving the safety performance of the battery monomer 100.

[0253] It can be understood that, in the case that 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 surface 1111b, at this time, 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 at this time, the third part 1121c can be directly connected to the first part 1121a.

[0254] In the embodiment, the sub-insulating layer 1121 further includes the third part 1121c, and the third part 1121c covers a part of the active material layer 113, so that the second part 1121b can completely cover the blank area 1111c, thereby further improving the safety performance of the battery monomer 100.

[0255] Referring to FIGS. 6, 8-10, in some embodiments, the active material layer 113 includes a main portion 1131 and a transition portion 1132 connected to the main portion 1131, the transition portion 1132 is located on a side of the main portion 1131 toward the end face 1111a, and the thickness of the transition portion 1132 gradually decreases in a direction from the main portion 1131 toward the end face 1111a; the third portion 1121c covers at least part of the transition portion 1132.

[0256] The main portion 1131 refers to a partial structure of the active material layer 113, and the main portion 1131 is mainly used for exchanging ions with the electrolyte to store and release electrical energy; the main portion 1131 is connected to and covers most of the corresponding side face 1111b; the transition portion 1132 refers to a partial structure of the active material layer 113, and the transition portion 1132 is located on a side of the main portion 1131 along the width direction Y of the current collector 111 toward the end face 1111a, and the transition portion 1132 is mainly used for connecting the third portion 1121c to provide a fixed basis for the third portion 1121c.

[0257] The thickness of the transition portion 1132 gradually decreases in a direction from the main portion 1131 toward the end face 1111a, and because the transition portion 1132 is located on the side face 1111b which is a plane or substantially a plane, the surface of the transition portion 1132 away from the side face 1111b should be an arc surface or an inclined surface, so that the thickness of the transition portion 1132 gradually decreases in a direction from the main portion 1131 toward the end face 1111a; for example, the surface of the transition portion 1132 away from the side face 1111b is an inclined surface, and the inclined surface gradually approaches the side face 1111b in a direction from the main portion 1131 toward the end face 1111a.

[0258] The third portion 1121c covers at least part of the transition portion 1132, that is, the third portion 1121c can completely cover the transition portion 1132, or only cover part of the transition portion 1132; because the third portion 1121c is connected to the active material layer 113, the third portion 1121c is connected to the transition portion 1132 to provide a fixed basis for the third portion 1121c through the transition portion 1132.

[0259] The thickness of the pole piece 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 pole piece 11, the third part 1121c is easy to protrude from the surface of the active material layer 113 away from the side surface 1111b, so that the thickness of the pole piece 11 at the third part 1121c is relatively thick. The relatively thick position at the third part 1121c can cause the distance between the pole piece 11 and the adjacent separator 12 to be too large, thereby negatively affecting the energy density of the battery monomer 100. In the process of winding and hot pressing the pole piece 11, the stress on the pole piece 11 at the third part 1121c is relatively large, and the stress concentration is more serious.

[0260] Accordingly, the active material layer 113 includes the main part 1131 and the transition part 1132, the third part 1121c covers the transition part 1132, and the thickness of the transition part 1132 gradually decreases. At this time, although the thickness of the pole piece 11 at the third part 1121c is the sum of the thickness of the current collector 111, the thickness of the two transition parts 1132, and the thickness of the two third parts 1121c, the thickness of the transition part 1132 gradually decreases, thereby reducing the height of the third part 1121c protruding from the active material layer 113, and even enabling the third part 1121c to be located below the surface of the active material layer 113 away from the side surface 1111b, so as to reduce the negative impact of the third part 1121c on the energy density of the battery monomer 100 and reduce the stress concentration at the third part 1121c.

[0261] Because of the need to set the third part 1121c to cover part of the active material layer 113 in order to reduce the safety risk caused by the exposure of the blank area 1111c, the transition part 1132 is set to enable the third part 1121c to 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 pole piece 11, thereby reducing the negative impact of the third part 1121c on the energy density of the battery monomer 100 and alleviating the stress concentration of the pole piece 11 at the third part 1121c.

[0262] In the embodiment, the active material layer 113 includes the transition part 1132 with a gradually decreasing thickness, and the third part 1121c covers at least part of the transition part 1132 to reduce the height of the third part 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 monomer 100 and further alleviating the stress concentration of the pole piece 11 at the insulating layer 112.

[0263] Referring to FIGS. 6, 8-10, in some embodiments, the size of the third portion 1121c in the width direction of the current collector 111 ranges from 0.1 mm to 1 mm.

[0264] 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 in the thickness direction Z of the current collector 111. Since 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.

[0265] Referring to FIGS. 8-10, the size of the third portion 1121c in the width direction Y of the current collector 111 is the size L3 shown in the figure, which ranges from 0.1 mm to 1 mm. For example, the size can be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, or other values.

[0266] In the case where there is a blank area 1111c on the side surface 1111b of the current collector 111, the sub-insulating layer 1121 can be connected to the current collector 111 through the second portion 1121b. At this time, the third portion 1121c is mainly used to enable the second portion 1121b to better cover the blank area 1111c. Therefore, the size of the third portion 1121c in the width direction Y of the current collector 111 should be relatively short.

[0267] For example, the size of the third portion 1121c in the width direction Y of the current collector 111 can be 0.1 mm. At this time, the third portion 1121c has less negative impact on the charge and discharge performance of the active material layer 113, and the charge and discharge performance of the tab 11 is better. At the same time, the width of the third portion 1121c on the transition portion 1132 is small, and the thickness of the tab 11 at the third portion 1121c is also small. Therefore, it is also possible to better reduce the negative impact on the energy density of the battery monomer 100 and better alleviate the stress concentration of the tab 11 at the third portion 1121c.

[0268] For example, the size of the third portion 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 stably connected to the current collector 111 through the third portion 1121c and cover the end surface 1111a. At the same time, it is also possible to reduce the negative impact of the third portion 1121c on the charge and discharge performance of the active material layer 113, and to reduce the negative impact on the energy density of the battery monomer 100 and to alleviate the stress concentration of the tab 11 at the third portion 1121c.

[0269] For example, the third part 1121c can have a size of 1 mm in the width direction Y of the current collector 111. In this case, the sub-insulating layer 1121 can be more stably connected to the current collector 111 through the third part 1121c and cover the end surface 1111a, so that the insulating layer 112 can better cover the end surface 1111a and the protruding structure 1112 and can improve the stability of the insulating layer 112.

[0270] The 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, thereby enabling the second part 1121b to better cover the blank area 1111c and reducing the risk of short circuit or damage caused by exposure of the blank area 1111c; meanwhile, the setting can also enable the third part 1121c not to easily protrude from the plane in which the surface of the corresponding side surface 1111b is located, or can reduce the height of the third part 1121c protruding from the plane in which the surface of the corresponding side surface 1111b is located, so as to reduce stress concentration at the third part 1121c in the winding and hot-pressing process, thereby being capable of reducing damage to the pole piece 11.

[0271] Referring to FIGS. 6, 8 and 12, in some embodiments, the sub-insulating layer 1121 includes a substrate layer 1121d and an adhesive layer 1121e provided on the substrate layer 1121d, and the adhesive layer 1121e is provided on the side of the substrate layer 1121d facing the current collector 111.

[0272] The substrate layer 1121d refers to a layered structure mainly used to provide a fixed basis in the sub-insulating layer 1121, and can be used to provide a fixed basis for the adhesive layer 1121e and can also play a protective role for the corresponding pole piece 11; according to the role of the substrate layer 1121d, the substrate layer 1121d should have a certain strength and a certain insulation capacity, and the material of the substrate layer 1121d can include plastic, rubber, ceramic and the like.

[0273] The adhesive layer 1121e refers to a layered structure mainly used to play a fixing role in the sub-insulating layer 1121, and is provided on the side of the substrate layer 1121d facing the current collector 111, so as to fix the substrate layer 1121d on the current collector 111; the material of the adhesive layer 1121e can include rubber, resin or other materials; the adhesive layer 1121e can be connected to the current collector 111 through light curing, heat curing or other curing methods.

[0274] In the case where the sub-insulating layer 1121 is connected to the current collector 111, the adhesive connection can cover the end surface 1111a and cover the protruding structure 1112, thereby playing a role in fixing the protruding structure 1112, and the base material 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 base material layer 1121d can also play a protective role for the current collector 111, reducing the damage that other structures can cause to the current collector 111.

[0275] The technical scheme of the embodiment provides some structures of the sub-insulating layer 1121, so that the sub-insulating layer 1121 includes the adhesive layer 1121e and the base material layer 1121d, so that the base material layer 1121d can be connected to the current 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 base material layer 1121d; at the same time, the base material layer 1121d can also play a role in protecting the current collector 111.

[0276] In some embodiments, the base material layer 1121d is an insulating structural layer.

[0277] The base material layer 1121d is an insulating structural layer, that is, the material of the base material layer 1121d includes an insulating material, so that the insulating layer 112 can better separate the current collector 111 covered thereby and the external environment (for example, the electrolyte or the adjacent other pole piece 11), so as to play a role in protecting the current collector 111 and reducing the occurrence of short circuit of the current collector 111; for example, the material of the base material layer 1121d can include polypropylene.

[0278] In the embodiment, the base material layer 1121d is an insulating structural layer, so as to reduce the risk of short circuit of the current collector 111.

[0279] Referring to FIGS. 6, 8, and 12, in some embodiments, the thickness of the base material layer 1121d ranges from 6 μm to 20 μm.

[0280] The thickness of the base material layer 1121d is the dimension of the base material layer 1121d in the arrangement direction of the base material layer 1121d and the adhesive layer 1121e; in the case where 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 base material 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 base material layer 1121d refers to the dimension of the base material layer 1121d in the thickness direction Z of the current collector 111, which ranges from 6 μm to 20 μm; for example, the dimension can be 6 μm, 8 μm, 10 μm, 12 μm, 14 μm, 16 μm, 18 μm, 20 μm, or other numerical values.

[0281] For example, the thickness of the substrate layer 1121d can be 6 μm. In this case, the thickness of the substrate layer 1121d is relatively small, so that the negative effect of the sub-insulating layer 1121 on the energy density of the battery cell 100 is small.

[0282] For example, the thickness of the substrate layer 1121d can be 13 μm. In this case, the substrate layer 1121d has a certain thickness, so that 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 separator 12. At the same time, the negative effect of the sub-insulating layer 1121 on the energy density of the battery cell 100 is reduced.

[0283] 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 large, so that the substrate layer 1121d can better protect the current collector 111 and better reduce the risk of the protruding structure 1112 piercing the insulating layer 112 and the adjacent separator 12.

[0284] In some embodiments, the thickness of the substrate layer 1121d is in a range of 6 μm to 20 μm. In this case, the protruding structure 1112 is difficult to pierce the substrate layer 1121d, and the substrate layer 1121d can protect the current collector 111. At the same time, the substrate layer 1121d is not easy to be punctured by static electricity, so that the substrate layer 1121d can better protect the current collector 111.

[0285] In some embodiments, the adhesive layer 1121e is an adhesive structure layer.

[0286] The adhesive layer 1121e is an adhesive structure layer, that is, the material of the adhesive layer 1121e includes an adhesive material, so that the adhesive layer 1121e can bond the substrate layer 1121d to the current collector 111, and the substrate layer 1121d is not easy to separate from the current collector 111, so that the substrate layer 1121d can better and more stably protect the current collector 111. At the same time, the adhesion of the adhesive layer can provide resistance to the protruding structure 1112 piercing the insulating layer 112, so that the protruding structure 1112 is more difficult to pierce the insulating layer 112. For example, the material of the adhesive layer 1121e includes polyacrylate.

[0287] It can be understood that, in the case where the sub-insulating layer 1121 includes the first part 1121a, the second part 1121b and the third part 1121c, at least part 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.

[0288] In the technical solution of the embodiment, the adhesive layer 1121e is a sticky structure layer, so as to bond the base material 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, so as to reduce the risk of the protruding structure 1112 piercing the insulating layer 112.

[0289] Referring to FIGS. 6, 8, and 12, in some embodiments, the thickness of the adhesive layer 1121e ranges from 3 μm to 10 μm.

[0290] The thickness of the adhesive layer 1121e is the dimension of the adhesive layer 1121e in the arrangement direction of the adhesive layer 1121e and the base material layer 1121d. In the case where 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 base material 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 base material layer 1121d refers to the dimension of the base material layer 1121d in the thickness direction Z of the current collector 111, which ranges from 3 μm to 10 μm. For example, the dimension can be 3 μm, 4 μm, 5 μm, 6 μm, 6.5 μm, 7 μm, 8 μm, 9 μm, 10 μm, or other values.

[0291] For example, the thickness of the adhesive layer 1121e can be 3 μm. At this time, the thickness of the adhesive layer 1121e is relatively small, so that the negative impact of the sub-insulating layer 1121 on the energy density of the battery cell 100 is small.

[0292] For example, the thickness of the adhesive layer 1121e can be 6.5 μm. The adhesive layer 1121e has a certain thickness, so that the adhesive layer 1121e can not only fix the base material 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 separator 12. At the same time, the negative impact of the sub-insulating layer 1121 on the energy density of the battery cell 100 can be reduced.

[0293] For example, the thickness of the adhesive layer 1121e can be 10 μm. At this time, the thickness of the adhesive layer 1121e is relatively large, so that the adhesive layer 1121e can not only fix the base material 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 separator 12.

[0294] The embodiment provides a thickness range of the adhesive layer 1121e, so that the adhesive layer 1121e can stably bond the base material layer 1121d to the current collector 111 and / or the active material layer 113, and the adhesive layer 1121e can also hinder the protruding structure 1112 from piercing the insulating layer 112.

[0295] Referring to FIGS. 6, 8-10, 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.

[0296] 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 can be covered by the insulating layer 112, and is also positively correlated with the length of the protruding structure 1112 that can be covered by the insulating layer 112; the size of the insulating layer 112 in the width direction of the current collector 111 ranges from 0.3 mm to 12 mm, and examples of the size can be 0.3 mm, 3.25 mm, 6.15 mm, 9.05 mm, 12 mm, or other values.

[0297] The size of the insulating layer 112 in the width direction Y of the current collector 111 ranges from 0.3 mm to 12 mm, so that the insulating layer 112 can be 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 separator 12 and short-circuiting with the adjacent tab 11.

[0298] For example, the size of the insulating layer 112 in the width direction Y of the current collector 111 is 0.3 mm, which can better reduce the space occupation of the insulating layer 112, thereby reducing the negative impact of the insulating layer 112 on the energy density of the battery monomer 100, and can better reduce the area of the insulating layer 112 covering the active material layer 113, thereby reducing the negative impact of the insulating layer 112 on the charge-discharge performance of the tab 11, under the premise that the insulating layer 112 can cover the protruding structure 1112 and be connected to the current collector 111.

[0299] For example, the size of the insulating layer 112 in the width direction Y of the current collector 111 is 6.15 mm, which can also adapt to the larger size of the protruding structure 1112, and can better cover the protruding structure 1112 and be stably connected to the current collector 111; at the same time, this setting can also reduce the space occupation of the insulating layer 112, and reduce the negative impact of the insulating layer 112 on the energy density of the battery monomer 100; this setting can also reduce the area of the insulating layer 112 covering the active material layer 113, thereby reducing the negative impact of the insulating layer 112 on the charge-discharge performance of the tab 11.

[0300] For example, the size of the insulating layer 112 in the width direction Y of the current collector 111 is 12 mm, so that the insulating layer 112 can accommodate more protruding structures 1112 with different sizes and better cover the protruding structures 1112 to reduce the risk of the protruding structures 1112 piercing the insulating layer 112 and the adjacent separator 12. Meanwhile, the insulating layer 112 can be more stably connected to the current collector 111, reducing the risk of the insulating layer 112 falling off after long-term soaking in the electrolyte.

[0301] The present embodiment provides a range of widths of the insulating layer 112, so that the insulating layer 112 can cover the protruding structures 1112 and be stably connected to the current collector 111 and / or the active material layer 113. Meanwhile, the space occupied by the insulating layer 112 can be reduced, and the negative impact of the insulating layer 112 on the energy density of the battery cell 100 can be reduced.

[0302] In some embodiments, the peeling strength of the insulating layer 112 ranges from 15 N / m to 20 N / m.

[0303] The peeling strength of the insulating layer 112 refers to the force required to peel the insulating layer 112 with a unit width from the current collector 111. The peeling strength of the insulating layer 112 reflects the adhesion strength of the insulating layer 112 to the current collector 111 and the stability of the insulating layer 112 soaked in the electrolyte. The peeling strength of the insulating layer 112 ranges from 15 N / m to 20 N / m. For example, the peeling strength can be 15 N / m, 16 N / m, 17 N / m, 18 N / m, 19 N / m, 20 N / m, or other values.

[0304] For example, after the insulating layer 112 is soaked in the electrolyte for 1000 hours, the peeling strength of the insulating layer 112 ranges from 15 N / m to 20 N / 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 the separation of the insulating layer 112.

[0305] To test the peeling strength of the insulating layer 112, the insulating layer 112 can be adhered to a sample (e.g., a copper foil) with the same size and material as the current collector 111. Then, the sample with the insulating layer 112 is soaked in the electrolyte for a period of time (e.g., 1000 hours) and taken out. Then, the soaked sample is adhered to a stainless steel plate and compacted so that the sample can be stably adhered 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 predetermined stable speed until the insulating layer 112 is separated from the sample. The displacement and force during the process are recorded by the tensile testing machine.

[0306] In an example, the insulating layer 112 is an insulating adhesive tape with a thickness of 13 μm and a width of 8 mm, the sample is an aluminum foil with a thickness of 13 μm, and the insulating adhesive tape is bonded to the aluminum foil; the aluminum foil with the bonded insulating adhesive tape is soaked in an electrolyte at 70°C for 200 h, 400 h, 600 h, 800 h, and 1000 h, respectively, and then taken out, at which time the insulating adhesive tape does not fall off; a high-iron tension machine is used, the aluminum foil after soaking is bonded to a stainless steel plate with double-sided tape, one side of the insulating adhesive tape faces outward and is compacted with a compression roller, so as to fix the entire sample on the tension machine; the tension machine is used to clamp one end of the adhesive tape and pull it upward at a speed of 50 mm / min, until the adhesive tape is completely peeled off from the aluminum foil, and the displacement and force in the process are recorded; in the case where the base material layer 1121d of the insulating adhesive tape is polypropylene with a thickness of 10 μm, and the bonding layer 1121e is polyacrylate with a thickness of 3 μm, the peeling strength of the insulating adhesive tape is 19.21 N / m.

[0307] The present embodiment provides a peeling strength range of 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 wetting environment.

[0308] Referring to FIGS. 4 and 5, in some embodiments, the battery cell 100 further includes an electrode assembly 10, which includes a positive electrode tab 114, a separator 12, and a negative electrode tab 115 arranged in sequence with intervals; the electrode tab 11 is the positive electrode tab 114.

[0309] The electrode tab 11 is the positive electrode tab 114, at which time the current collector 111 can be an 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 part 1131 close to the tab part 1113, and covers part of the tab part 1113, and the second insulating layer 112 is arranged on the end surface 1111a of the main body part 1131 away from the tab part 1113.

[0310] In an example, in the case where the electrode tab 11 is the positive electrode tab 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 tab part 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.

[0311] The burr generated by processing of the positive electrode tab 114 short-circuits the active material layer 113 of the negative electrode tab 115, which is more harmful; accordingly, the present embodiment makes the electrode tab 11 the positive electrode tab 114, so as to reduce the safety risk caused by burr short-circuiting.

[0312] In some embodiments, the preparation process of the positive electrode sheet 114 is as follows:

[0313] The material of the active material layer 113 of the positive electrode sheet 114 includes an active material lithium iron phosphate (LiFeP04, LFP), a 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.

[0314] 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.

[0315] The positive electrode slurry is coated on both sides 1111b of the aluminum foil (current collector 111 of the positive electrode sheet 114), and is sequentially subjected to drying, rolling, die cutting, and slitting.

[0316] The two insulating adhesive papers are respectively attached to the die-cut edges on both sides of the aluminum foil, and the portions of the two insulating adhesive papers are attached to each other and form the insulating layer 112; the widths of the portions of the corresponding active material layer 113 covered by the two insulating adhesive papers are 0.2 mm and 0.8 mm, respectively.

[0317] In some embodiments, the preparation process of the negative electrode sheet 115 is as follows:

[0318] The material of the active material layer 113 of the negative electrode sheet 115 includes an active material graphite, a 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.

[0319] The dispersion solvent is ionized water, and the second mixed slurry is dispersed using the dispersion solvent to obtain a negative electrode slurry.

[0320] The negative electrode slurry is coated on both sides 1111b of the copper foil (current collector 111 of the negative electrode sheet 115), and is sequentially subjected to drying, rolling, die cutting, and slitting to obtain the negative electrode sheet 115.

[0321] In some embodiments, the sub-insulating layer 1121 is an insulating adhesive paper, the base material layer 1121d of which is made of polypropylene (PP) and has a thickness of 10 μm; the adhesive layer 1121e is made of polyacrylate (PA) and has a thickness of 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.

[0322] In some embodiments, the base film of the separator 12 has a thickness of 7 μm and is made of polypropylene.

[0323] In some embodiments, the electrode assembly 10 is prepared as follows:

[0324] The prepared positive electrode sheet 114, the separator 12 and the negative electrode sheet 115 are wound, and then are subjected to heat pressing to obtain the electrode assembly 10.

[0325] In some embodiments, the electrolyte is prepared as follows:

[0326] Lithium hexafluorophosphate (LFPF6) is added into ethylene carbonate (EC) successively, and the mass fraction of the lithium hexafluorophosphate in the electrolyte is controlled to be 12.5%, to obtain the electrolyte.

[0327] In some embodiments, the battery cell 100 is assembled as follows:

[0328] The electrode assembly 10 is placed in the outer packaging shell 20 (for example, an aluminum shell), the tab portion 1113 of the positive electrode sheet 114 and the negative electrode sheet 115 is welded to the electrode terminal 40 of the end cover 30, and is subjected to drying; the prepared electrolyte is injected into the shell 20, and then is subjected to standing, formation and capacity distribution to complete the preparation of the battery device 1000.

[0329] In some embodiments, the battery cell 100 includes an electrode sheet 11, which includes a current collector 111, an active material layer 113 and an insulating layer 112.

[0330] The current collector 111 includes a current collector body 1111, which includes two side surfaces 1111b and two end surfaces 1111a, and a protruding structure 1112 is formed on the end surface 1111a; the current collector 111 further includes a tab portion 1113 connected to the end surface 1111a.

[0331] The protruding structure 1112 includes a first protruding portion 1112a, and the length of the first protruding portion 1112a ranges from 40 μm to 200 μm; the protruding structure 1112 further includes a second protruding portion 1112b, and the second protruding portions 1112b are arranged at intervals, and a connecting portion 1112c is arranged between any two adjacent second protruding portions 1112b, and the length of the second protruding portion 1112b ranges from 15 μm to 40 μm.

[0332] The active material layer 113 includes a main body portion 1131 and a transition portion 1132 connected to the main body portion 1131, the transition portion 1132 is located on the side of the main body portion 1131 towards the end face 1111a, and the thickness of the transition portion 1132 gradually decreases in the direction of the main body portion 1131 pointing to the end face 1111a; the part of the current collector 111 not covered by the active material layer 113 is a blank area 1111c, the blank area 1111c is located on the side face 1111b of the current collector main body 1111 and close to the tab portion 1113.

[0333] The insulating layer 112 includes two sub-insulating layers 1121 connected to the two side faces 1111b respectively; the thickness of the sub-insulating layer 1121 can be set according to the thickness of the first protruding portion 1112a and the second protruding portion 1112b; the sub-insulating layer 1121 includes a first portion 1121a, a second portion 1121b and a third portion 1121c connected in sequence. Among them, the first portion 1121a extends out of the current collector 111 and covers part of the tab portion 1113, and the first portion 1121a can also be connected with another first portion 1121a to cover the corresponding end face 1111a and cover the protruding structure 1112; the second portion 1121b covers the blank area 1111c of the current collector 111, and the third portion 1121c covers at least part of the transition portion 1132.

[0334] The insulating layer 112 includes a substrate layer 1121d and an adhesive layer 1121e, wherein one side of the adhesive layer 1121e is connected to the current collector 111, and the other side is connected to the substrate layer 1121d.

[0335] In the second aspect, some embodiments of the present application provide a battery device 1000, which includes the battery monomer 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 to cause short circuit, so that the battery device 1000 can have higher stability.

[0336] In the third aspect, some embodiments of the present application also provide an energy storage device 1, which includes the battery monomer 100 provided by some embodiments of the first aspect, or the battery device 1000 provided by some embodiments of the second aspect.

[0337] The energy storage device 1 includes one or more battery clusters to improve the voltage and capacity of the energy storage device 1. The battery cluster can include a plurality of battery devices 1000, and the plurality of battery devices 1000 are connected in series through the busbar component to improve the voltage of the energy storage device 1. When the energy storage device 1 includes a plurality of battery clusters, the plurality of battery clusters are connected in parallel to improve the capacity of the energy storage device 1.

[0338] The energy storage device 1 can be used in an energy storage power station, a wind power system, a solar power system, a mobile power system, or a temporary power supply system, etc. The energy storage device 1 can store electric energy as needed and output the electric energy at an appropriate time. For example, the energy storage device 1 can store electric energy at a low electricity consumption valley, and provide electric energy for related users or electric equipment at a high electricity consumption peak. The energy storage system provided by the embodiments of the present application can be any power system that needs to use the energy storage device 1.

[0339] In some embodiments, the energy storage device 1 is an energy storage container or an energy storage cabinet.

[0340] In some embodiments, the energy storage device 1 can include a cabinet body and one or more battery clusters, and the battery clusters are accommodated in the cabinet body.

[0341] In some embodiments, the energy storage device 1 can include a thermal management module, a master control module, a general control module, a power distribution module, and a fire-fighting module, etc.

[0342] As an example, the thermal management module can include a liquid cooling unit that provides cooling liquid for adjusting the temperature of the battery monomer 100 to each battery device 1000 through a pipeline.

[0343] As an example, the master control module can serve as a battery management unit of the battery cluster, for monitoring and managing the battery cluster. The master control module can monitor information such as current, voltage, power, or temperature of the battery cluster. For example, the charging and discharging current and voltage of the battery cluster can be controlled. The master control module includes a slave battery management unit (SBMU), a fusion switch, and other modules.

[0344] As an example, the general control module can serve as a battery management unit of the energy storage device 1, for monitoring and managing the energy storage device 1. The general control module can monitor information such as current, voltage, power, state of charge, or temperature of the energy storage device 1. For example, the charging and discharging current and voltage of the energy storage device 1 can be controlled. As an example, the general control module includes an insulation monitoring module (IMM), a master battery management unit (MBMU), an Ethernet (ETH) module, and an optical fiber conversion module, etc.

[0345] As an example, the fire-fighting module includes a control panel, a detector, an alarm device, etc., for detecting, alarming, or extinguishing the energy storage system.

[0346] As an example, the power distribution module can be used to distribute power to the modules that need power in the energy storage device 1.

[0347] In a fourth aspect, referring to FIG. 13, some embodiments of the present application further provide an energy storage system, which comprises the power conversion device 2 and the energy storage device 1 provided by some embodiments of the third aspect, and the power conversion device 2 is configured to electrically connect the power generation device 3 and the energy storage device 1.

[0348] The energy storage system can comprise one or more energy storage devices 1 and a power conversion device 2 (PCS), and the power conversion device 2 is configured to be connected between the power generation device 3 and the energy storage device 1. The power generation device 3 is configured to generate electric energy, and the electric energy generated by the power generation device 3 can be stored in the energy storage device 1 through the power conversion device 2. As an example, the power generation device 3 can be a solar panel, a water power generation device, a fire power generation device, a wind power generation device, etc. The specific type of the power generation device 3 is not limited in the present application.

[0349] In a fifth aspect, some examples of the present application further provide a power consumption device, which comprises 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, or the energy storage device 1 provided by some embodiments of the third aspect, or the energy storage system provided by some embodiments of the fourth aspect. The battery cell 100 or the battery device 1000 is configured to store or provide electric energy.

[0350] In a sixth aspect, referring to FIG. 14, some embodiments of the present application further provide a charging network, which comprises the charging pile 4 and the energy storage device 1 provided by some embodiments of the third aspect, or the energy storage system provided by some embodiments of the fourth aspect. The energy storage device 1 or the energy storage system is configured to provide electric energy for the charging pile 4.

[0351] The charging pile 4 is electrically connected with the energy storage device 1, and the energy storage device 1 is configured to provide electric energy for the charging pile 4. The charging pile 4 is electrically connected with the battery device 1000 in the energy storage device 1 through a cable, and the battery device 1000 can provide the electric energy stored therein to the charging pile 4. The charging pile 4 has one or more connectors 5, which are configured to be connected with a power consumption device (such as a vehicle), so as to charge the power consumption device.

[0352] The energy storage device 1 can be located inside the charging pile 4 (for example, a charging and storage integrated machine), or can be located outside the charging pile 4.

[0353] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them. Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some or all of the technical features can be replaced equivalently. Such modifications or replacements do not change the essence of the corresponding technical solutions, which should be covered in the scope of the claims and the specification of the present application. In particular, the technical features mentioned in each embodiment can be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized by, The pole piece comprises: a current collector comprising two end faces located at opposite ends along a width direction of the current collector, and two side faces located at opposite sides along a thickness direction of the current collector, the end faces being provided with protruding structures; an insulating layer provided on the current collector, the insulating layer covering at least the end faces and the protruding structures.

2. The battery cell of claim 1, wherein, The insulating layer covers the protruding structures.

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 of claim 3, wherein, The needle penetration strength of the insulating layer is greater than or equal to 300 gf.

5. The battery cell of any one of claims 1-4, wherein, The protruding structures comprise at least two first protruding portions arranged at intervals along a length direction of the current collector, the first protruding portions being formed on the end faces. The insulating layer covers the first protruding portions.

6. The battery cell of claim 5, wherein, The length of the first protruding portions ranges from 40 μm to 200 μm.

7. The battery cell according to claim 5 or 6, characterized in that In the length direction of the current collector, the number of the first protruding portions 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 of any one of claims 1-4, wherein, The protruding structures further comprise a plurality of second protruding portions arranged at intervals along the length direction of the current collector, and a connecting portion arranged between adjacent two second protruding portions, the connecting portion and the second protruding portions being formed on the end faces. The length of the connecting portion is less than the length of the second protruding portions, and the insulating layer covers the second protruding portions and the connecting portion.

9. The battery cell of claim 8, wherein, The length of the second protruding portions ranges from 15 μm to 40 μm.

10. The battery cell of claim 9, wherein, In the length direction of the current collector, the number of the second protruding portions within a size range of 1 mm ranges from 3 to 5. The thickness of the insulating layer ranges from 9 μm to 13 μm.

11. The battery cell of claim 9, wherein, In the length direction of the current collector, the number of the second protruding portions 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 of any one of claims 1-11, wherein, The insulating layer comprises two sub-insulating layers corresponding to the two side faces, the sub-insulating layers comprising a first portion and a second portion connected to the first portion, the second portion being connected to the side face. At least part of the first portion is connected to the first portion of another sub-insulating layer adjacent thereto, and the two first portions cover the protruding structures.

13. The battery cell of claim 12, wherein, In the width direction of the current collector, the 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 pole piece further comprises an active material layer provided on the side face, the active material layer covering at least part of the side face. The sub-insulating layer is connected to the active material layer.

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

16. The battery cell of claim 15, wherein, 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 of claim 15 or 16, wherein, The sub-insulating layer further comprises a third portion connected to the second portion on a side opposite to the first portion, the second portion covering the blank area, and the third portion covering part of the active material layer.

18. The battery cell of claim 17, wherein, The active material layer comprises a main body portion and a transition portion connected to the main body portion, the transition portion is arranged on the side of the main body portion facing the end face, and the thickness of the transition portion gradually decreases along the direction from the main body portion to the end face. The third portion covers at least part of the transition portion.

19. The battery cell of claim 18, wherein, 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 of any one of claims 12-19, wherein, The sub-insulating layer comprises a base material layer and an adhesive layer arranged on the base material layer, and the adhesive layer is arranged on the side of the base material layer facing the current collector.

21. The battery cell of claim 20, wherein, The base material layer is an insulating structural layer.

22. The battery cell of claim 20 or 21, wherein, The thickness of the base material layer ranges from 6 μm to 20 μm.

23. The battery cell of any one of claims 20-22, wherein, The adhesive layer is an adhesive structural layer.

24. The battery cell of any one of claims 22-23, wherein, The thickness of the adhesive layer ranges from 3 μm to 10 μm.

25. The battery cell of any one of claims 1-24, wherein, 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 of any one of claims 1-25, wherein, The peeling strength of the insulating layer ranges from 15 N / m to 20 N / m.

27. The battery cell of any one of claims 1-26, wherein, The battery cell further comprises an electrode assembly, the electrode assembly comprises a positive electrode sheet, a separator and a negative electrode sheet arranged in sequence with intervals. The electrode sheet is the positive electrode sheet.

28. A battery device, characterized by The battery cell comprises the battery cell according to any one of claims 1-27.

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

30. An energy storage system, comprising: The energy storage device comprises a power conversion device and a battery cell according to claim 29, the power conversion device is used to electrically connect a power generation device and the energy storage device.

31. An electrical device, comprising: The battery cell according to any one of claims 1-27, 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 by, The energy storage device or the energy storage system is used to provide electric energy for the charging pile. The energy storage device or the energy storage system is used to provide electric energy for the charging pile.

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