Battery cell, related device and system, and charging network

Abstract

A battery cell (100), a related device and system, and a charging network. The battery cell (100) comprises an electrode plate (11), wherein the electrode plate (11) comprises: a current collector (111), the current collector (111) comprising a body portion (1111) and a tab portion (1112) connected to the body portion (1111), the tab portion (1112) extending from one side of the body portion (1111) along the direction of width of the current collector (111) in a direction away from the body portion (1111); and an insulating layer (112), which is disposed on the tab portion (1112) and covers at least a part of the tab portion (1112), wherein the insulating layer (112) is located on the side of the tab portion (1112) close to the body portion (1111). In the provided battery cell (100), the insulating layer (112) is provided, and the insulating layer (112) covers at least a part of the tab portion (1112), so as to increase the strength of the tab portion (1112) by means of the insulating layer (112) and reduce the bending amount of the tab portion (1112), thereby reducing the risk of short-circuiting due to the tab portion (1112) being bent and inserted into the gap of the electrode plate (11), and improving the safety performance and stability of the battery cell (100).

Description

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

[0001] The present application belongs to the technical field of battery, and particularly relates to a battery cell, a battery device, an energy storage device, an energy storage system, a power consumption device 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] After the tab is welded, the lower pressing of the end cover may cause the tab to be partially inserted between the adjacent tabs, resulting in a short circuit. In addition, during use of the battery, the battery cell may be subjected to impact and vibration, which may also cause the tab to be partially inserted between the adjacent tabs and result in a short circuit.

[0004] SUMMARY

[0005] In view of the above problems, the present application provides a battery cell, a battery device, an energy storage device, an energy storage system, a power consumption device and a charging network to improve the problem that the tab is easily inserted between the tabs and causes a short circuit.

[0006] In a first aspect, some embodiments of the present application provide a battery cell, comprising a tab, the tab comprising: a current collector, the current collector comprising a main body portion and a tab portion connected to the main body portion, the tab portion extending from one side of the main body portion in a width direction of the current collector towards a direction away from the main body portion; and an insulating layer provided on the tab portion and covering at least part of the tab portion, the insulating layer being located on the side of the tab portion close to the main body portion.

[0007] In the technical solution of the present embodiment, the insulating layer is provided and covers at least part of the tab portion, so as to increase the strength of the tab portion through the insulating layer, reduce the bending amplitude of the tab portion, thereby reducing the risk of short circuit caused by the tab portion bending and inserting into the gap between the tabs, and improving the safety performance and stability of the battery cell.

[0008] In some embodiments, the tab portion has at least two and is arranged at intervals in a length direction of the current collector; the insulating layer has at least two and is arranged correspondingly to the tab portion, and each insulating layer is arranged at intervals in the length direction of the current collector.

[0009] In the technical solution of the present embodiment, the insulating layer is arranged correspondingly to the tab portion, so as to mainly use the insulating layer to improve the strength of the tab portion; at the same time, the insulating layers are arranged at intervals, so as to reduce the part of the insulating layer that does not cover the tab portion to occupy the space, thereby being able to reduce the negative impact of the insulating layer on the energy density of the battery cell.

[0010] In some embodiments, the size of the insulating layer in the length direction of the current collector is less than or equal to the size of the tab portion.

[0011] The technical solution of the present embodiment provides that some insulating layers cover the size range of the tab portion in the length direction of the current collector. On the premise that the insulating layer can improve the strength of the tab portion, the insulating layer is less likely to extend beyond the tab portion, thereby better reducing the occupation of space by the insulating layer, and thus better reducing the negative impact of the insulating layer on the energy density of the battery cell.

[0012] In some embodiments, the orthographic projection of the insulating layer and the orthographic projection of the tab portion at least partially overlap on the same projection plane perpendicular to the thickness direction of the current collector, and the ratio of the size of the orthographic projection of the insulating layer to the orthographic projection of the tab portion in the width direction of the current collector is less than or equal to 1:3.

[0013] The technical solution of the present embodiment provides that some insulating layers cover the size range of the tab portion in the width direction of the current collector, so that the insulating layer can not only improve the strength of the tab portion to reduce the bending amplitude of the tab portion, but also reduce the negative impact of the insulating layer on the conduction performance of the tab portion.

[0014] In some embodiments, the yield strength of the insulating layer is greater than or equal to 25 MPa.

[0015] The technical solution of the present embodiment provides a yield strength range of some insulating layers, so that the insulating layer can better provide support for the tab portion to reduce the bending amplitude of the tab portion, thereby better preventing the tab portion from being inserted between adjacent tab sheets to cause short circuit, and better improving the stability and safety of the battery cell.

[0016] In some embodiments, the yield strength of the insulating layer is less than or equal to 100 MPa.

[0017] The technical solution of the present embodiment further provides a yield strength range of some insulating layers. On the premise that the insulating layer can provide support for the tab portion, the setting also limits the upper limit of the yield strength of the insulating layer, so that the tab portion can have a certain bending ability to meet the demand of electrical connection between the tab portion and the external structure, and can reduce the negative impact of the tab portion on the energy density of the battery cell. At the same time, this setting can also reduce the demand for the material and thickness of the insulating layer, thereby reducing the processing difficulty and cost.

[0018] In some embodiments, the thickness of the insulating layer is greater than or equal to 9 μm.

[0019] The technical scheme of the embodiment provides a thickness range of the insulating layer. Since the thickness of the insulating layer is positively correlated with the support performance of the insulating layer, the thickness of the insulating layer is greater than or equal to 9 microns, so as to limit the lower limit of the support performance that the insulating layer can provide for the tab part, thereby preventing the tab part from being inserted between the current collectors.

[0020] In some embodiments, the thickness of the insulating layer ranges from 9 microns to 30 microns.

[0021] The technical scheme of the embodiment further provides a thickness range of the insulating layer. On the premise that the insulating layer can provide support for the tab part, the thickness of the insulating layer is also limited to an upper limit, so that the tab part has a certain bending ability to meet the requirement of electrical connection between the tab part and an external structure, and the negative impact of the tab part on the energy density of the battery cell is reduced. Meanwhile, the space occupied by the insulating layer is reduced, and the negative impact of the insulating layer on the energy density of the battery cell is reduced.

[0022] In some embodiments, the main body part includes two end faces opposite to each other along the width direction of the current collector, and the main body part further includes two side faces opposite to each other along the thickness direction of the current collector, and the tab part is formed on the end faces. The active material layer is arranged on the side faces, and the active material layer covers at least part of the side faces. In the same projection plane perpendicular to the thickness direction of the current collector, the normal projection of the insulating layer at least partially overlaps the normal projection of the side face.

[0023] In the technical scheme of the embodiment, the insulating layer can cover not only the tab part but also part of the side face of the main body part and / or part of the active material layer, so that the insulating layer can not only provide support for the tab part but also improve the connection strength between the tab part and the main body part, thereby preventing the tab part from being torn at the connection position between the tab part and the main body part, and further improving the safety and stability of the battery cell.

[0024] In some embodiments, the insulating layer includes two sub-insulating layers corresponding to the two side faces, and the sub-insulating layer includes a first part and a second part connected to the first part, and the first part covers at least part of the tab part. In the same projection plane perpendicular to the thickness direction of the current collector, the normal projection of the second part at least partially overlaps the normal projection of the side face.

[0025] The technical scheme of the embodiment provides a specific structure of the insulating layer, which is formed by two sub-insulating layers connected to each other. The sub-insulating layer includes a first part and a second part, the first part covers at least part of the tab part, and the second part covers part of the side face, so that the insulating layer can not only improve the strength of the tab part but also improve the connection strength between the tab part and the main body part.

[0026] In some embodiments, the active material layer covers a portion of the corresponding side surface, and a blank area is formed on the side surface near one side of the tab portion, and the second portion covers at least a portion of the blank area.

[0027] In the technical solution of the embodiment, the second portion can cover at least a portion of the blank area to protect the main body portion, and the area of the main body portion exposed to the outside can be reduced, so that the short circuit and the like are reduced, and the safety performance of the battery monomer is improved.

[0028] In some embodiments, the sub-insulating layer further comprises a third portion connected to the second portion on the side opposite to the first portion, the second portion covers the blank area, and the third portion covers a portion of the active material layer.

[0029] In the technical solution of the embodiment, the sub-insulating layer further comprises a third portion, and the third portion covers a portion of the active material layer, so that the second portion can completely cover the blank area, and the safety performance of the battery monomer is further improved.

[0030] In some embodiments, in the projection plane perpendicular to the thickness direction of the current collector, the size range of the orthographic projection of the third portion is 0.1mm-1mm.

[0031] The technical solution of the embodiment provides a size of the third portion in the width direction of the current collector, and under the premise that the third portion can cover the active material layer, the size of the third portion in the width direction of the current collector is small, so that the negative influence of the third portion on the charge and discharge capacity of the active material layer is reduced.

[0032] In some embodiments, the active material layer completely covers the corresponding side surface, and the second portion covers a portion of the active material layer.

[0033] In the technical solution of the embodiment, the active material layer completely covers the side surface of the main body portion, so that the active material layer has a larger contact area with the electrolyte, and the active material layer has better charge and discharge capacity; and the second portion covers a portion of the active material layer, so that the insulating layer can improve the strength of the tab portion and the connection strength of the connection part between the tab portion and the main body portion.

[0034] In some embodiments, in the projection plane perpendicular to the thickness direction of the current collector, the size range of the orthographic projection of the second portion is 0.1mm-1mm.

[0035] The technical solution of the embodiment provides a size of the second portion in the width direction of the current collector, and under the premise that the second portion can be connected to the active material layer, the size of the second portion in the width direction of the current collector is small, so that the negative influence of the second portion on the charge and discharge capacity of the active material layer is reduced.

[0036] In some embodiments, the tab portions are at least two and are arranged at intervals along the length direction of the current collector; the insulating layer is one, and the insulating layer covers at least one tab portion.

[0037] In the technical scheme of the embodiment, the insulating layer is only one, and one insulating layer can cover one or more tab portions, so that the insulating layer can increase the strength of the tab portion and reduce the bending amplitude of the tab portion, and can also reduce the difficulty of processing and setting of the insulating layer.

[0038] In some embodiments, the insulating layer comprises a substrate layer and an adhesive layer provided on the substrate layer, the adhesive layer is provided on the side of the substrate layer facing the current collector, and the adhesive layer is connected to at least one tab portion.

[0039] The technical scheme of the embodiment provides the structure of some sub-insulating layers, so that the sub-insulating layer comprises an adhesive layer and a substrate layer, so that the substrate layer can be connected to the tab portion through the adhesive layer, so that the substrate layer can provide support for the tab portion and improve the strength of the tab portion, and so that the substrate layer can also play a role in protecting the tab portion.

[0040] In some embodiments, the battery monomer comprises an electrode assembly, the electrode assembly comprises a tab, and the tab comprises at least two tab portions arranged in layers.

[0041] The technical scheme of the embodiment provides the specific structure of the tab of the electrode assembly, so that the tab comprises at least two tab portions arranged in layers, and an insulating layer is provided on each tab portion, so that the tab of the electrode assembly can have higher strength under the support of the multiple insulating layers, so that the tab is less likely to be inserted between the tab pieces.

[0042] In some embodiments, at least part of each tab portion is flattened.

[0043] The technical scheme of the embodiment provides the specific structure of the tab of the electrode assembly, so that at least part of each tab portion is flattened to form the tab, so that the electrode assembly can meet the needs of cylindrical battery monomers and the like.

[0044] In a second aspect, some embodiments of the application further provide a battery device comprising the battery monomer provided by some embodiments of the first aspect.

[0045] In a third aspect, some embodiments of the application further provide an energy storage device comprising a plurality of battery monomers provided by some embodiments of the first aspect, or a plurality of battery devices provided by some embodiments of the second aspect.

[0046] The battery monomer or the battery device is used for storing or providing electric energy.

[0047] 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 configured to electrically connect the power generation device and the energy storage device.

[0048] 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 configured to store or provide electric energy.

[0049] 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.

[0050] The energy storage device or the energy storage system is configured to provide electric energy for the charging pile.

[0051] The above description is merely a summary of the technical solutions of the present application. In order to enable one skilled in the art to better understand the technical means of the present application, and to implement the present application according to the contents of the description, and in order to enable the above and other purposes, characteristics and advantages of the present application to be more apparent, the specific embodiments of the present application are described in detail below. DETAILED DESCRIPTION BRIEF DESCRIPTION OF DRAWINGS

[0052] 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:

[0053] FIG. 1 is a structural schematic diagram of a vehicle provided by some embodiments of the present application;

[0054] FIG. 2 is an exploded structural schematic diagram of a battery device according to some embodiments of the present application;

[0055] FIG. 3 is an exploded structural schematic diagram of a battery cell according to some embodiments of the present application;

[0056] FIG. 4 is a structural schematic diagram of an electrode assembly according to some embodiments of the present application;

[0057] FIG. 5 is a perspective structural schematic diagram of an electrode assembly according to some embodiments of the present application;

[0058] FIG. 6 is a structural schematic diagram of a pole piece according to some embodiments of the present application;

[0059] FIG. 7 is a sectional view schematic diagram of A-A in FIG. 6 according to some embodiments of the present application;

[0060] Fig. 8 is a cross-sectional view of A-A in Fig. 6 according to some embodiments of the present application;

[0061] Fig. 9 is a cross-sectional view of A-A in Fig. 6 according to some other embodiments of the present application;

[0062] Fig. 10 is an enlarged view of B in Fig. 8;

[0063] Fig. 11 is an exploded structural schematic view of a battery device according to some embodiments of the present application;

[0064] Fig. 12 is an exploded structural schematic view of a battery cell according to some embodiments of the present application;

[0065] Fig. 13 is a structural schematic view of an energy storage system according to some embodiments of the present application;

[0066] Fig. 14 is a structural schematic view of a charging network according to some embodiments of the present application.

[0067] The meanings of the reference signs in the figures are as follows: 1, energy storage device; 2, power conversion device; 3, power generation device; 4, charging pile; 5, connector; 1000, battery device; 100, battery cell; 10, electrode assembly; 11, electrode sheet; 111, current collector; 1111, main body portion; 1111a, end surface; 1111b, side surface; 1111c, blank area; 1112, 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; 12, separator; 13, tab; 20, case; 30, end cap; 40, electrode terminal; 200, box; 201, upper box; 202, lower box; 2000, motor; 3000, controller. Embodiments of the present application

[0068] 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.

[0069] 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 of the present application 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.

[0070] 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 specified and limited.

[0071] Reference herein to "embodiments" means that the particular features, structures, or characteristics described in connection with the embodiments 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 a separate or alternative embodiment to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0072] 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 " / " herein generally represents an "or" relationship between the front and rear associated objects.

[0073] 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).

[0074] In the description of the embodiments of the present application, 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 indicate the orientation or positional relationship based on the orientation or positional relationship 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.

[0075] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connection", "connection", "fixing", and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0076] 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 the energy storage power supply system of water power, fire power, wind power and solar power station, but also widely applied to 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.

[0077] After the tab is welded, the lower pressing of the end cover during the assembly process may cause part of the tab to be inserted between the adjacent pole pieces, resulting in a short circuit. Specifically, after the tab of the electrode assembly is connected to the electrode terminal, the electrode assembly is assembled into the shell, and then the end cover carrying the electrode terminal is covered on the shell. In order to reduce the negative impact on the energy density of the battery monomer, the space between the electrode assembly and the end cover is usually small, which causes the tab to be bent after the end cover is covered; due to the material of the tab, the strength of the tab is usually poor, and the bent part of the tab is easily inserted between the pole pieces and short-circuited with the pole pieces.

[0078] According to the above installation process, even if the tab does not insert between the pole pieces during the installation process, due to the strength of the tab, the risk of the tab inserting between the pole pieces during the subsequent transportation and use of the battery monomer is still high. For example, during the use of the battery, the battery monomer is subjected to impact and vibration, which may cause part of the tab to be inserted between the adjacent pole pieces and cause a short circuit.

[0079] Based on the above considerations, in order to alleviate the problem that the tab is easily inserted between the pole pieces to cause a short circuit, the battery monomer provided by the embodiments of the present application sets an insulating layer on the pole piece of the battery monomer to cover at least part of the tab part through the insulating layer; at the same time, the insulating layer is located on the side of the tab part close to the main body part.

[0080] In such a battery monomer, the insulating layer can improve the strength of the tab part to reduce the bending amplitude of the tab part, thereby reducing the risk of the tab part inserting between the pole pieces; by locating the insulating layer on the side of the tab part close to the main body part, in the case of deformation of the tab part, the part of the tab part covered with the insulating layer is less likely to deform or has a smaller deformation amount, so as to increase the distance between the end of the tab part away from the main body part and the electrode assembly, so that the end of the tab part away from the main body part can have a larger deformation space, thereby further reducing the risk of the tab part inserting between the pole pieces.

[0081] The battery cell disclosed in the embodiments of the present application can be used in a power consumption device using the battery device as a power source or a variety of energy storage systems using the 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 automobile, a ship, a spacecraft, and the like. Among them, the electric toy can include a fixed or mobile electric toy, such as a game console, an electric automobile toy, an electric ship toy, and an electric aircraft toy, and the like, and the spacecraft can include an airplane, a rocket, a space shuttle, a spacecraft, and the like.

[0082] The following embodiments are described by taking a vehicle as an example for convenience of description.

[0083] Referring to FIG. 1, FIG. 1 is a structural schematic diagram of a vehicle as a power consumption device 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 source 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.

[0084] In some embodiments of the present application, the battery device 1000 can not only be used as an operating power source of the vehicle, but also be used as a driving power source of the vehicle, to replace or partially replace fuel or natural gas to provide driving power for the vehicle.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] Referring to FIG. 2 and FIG. 3, the battery cell 100 refers to the smallest unit that constitutes the battery device 1000. As shown in FIG. 3, the battery cell 100 includes an end cover 30, a case 20, an electrode assembly 10, and other functional components.

[0089] 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 components in the shell 20 from the end cover 30 to reduce the risk of short circuit. For example, the insulating member can be plastic, rubber, etc.

[0090] 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 rectangular parallelepiped, cylindrical, 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.

[0091] 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 and a negative electrode sheet, and a separator 12 is generally provided between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet and the negative electrode sheet 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 13. The positive tab 13 and the negative tab 13 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 active material and the negative active material react with the electrolyte, and the tabs 13 are connected to the electrode terminal 40 to form a current loop.

[0092] In a first aspect, with reference to FIGS. 4-9, 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 a main body portion 1111 and a tab portion 1112 connected to the main body portion 1111, the tab portion 1112 extending from one side of the main body portion 1111 along the width direction of the current collector 111 towards a direction away from the main body portion 1111; the insulating layer 112 is provided on the tab portion 1112 and covers at least part of the tab portion 1112, the insulating layer 112 being located on the side of the tab portion 1112 closer to the main body portion 1111.

[0093] 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.

[0094] The current collector 111 refers to a structure in the electrode sheet 11 that is mainly used to support the flow of current. The main function of the current collector 111 is to provide an ion conductor in electrochemical reactions to support the flow of current, and to 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 device 1000, for example, the current collector 111 can be a copper foil, an aluminum foil, or a structure made of other materials.

[0095] The body part 1111 refers to a part of the current collector 111 for carrying active materials, and the active materials can be formed on the body part 1111. The tab part 1112 refers to a part of the current collector 111 extending outward from the body part 1111, and the tab part 1112 is used to make the pole piece 11 conductive with the circuit outside the electrode assembly 10. The tab part 1112 extends from one side of the body part 1111 to outside the body part 1111, and the tab part 1112 extends along the width direction Y of the current collector 111. The tab part 1112 can be integrally formed with the body part 1111, or can be connected to the body part 1111 by means of gluing, welding, etc. The tab part 1112 can be one, or two or more.

[0096] The insulation layer 112 refers to a layered structure of the pole piece 11 mainly used to improve the strength of the tab part 1112. The insulation layer 112 is provided on the tab part 1112 to improve the strength of the tab part 1112, so as to limit the bending amplitude of the tab part 1112. The insulation layer 112 covers at least part of the tab part 1112, i.e. the insulation layer 112 can completely cover the tab part 1112, or can only cover part of the tab part 1112.

[0097] It can be understood that in the case where the insulation layer 112 completely covers the tab part 1112, part of the tab part 1112 can be exposed by cutting, melting, etc. to facilitate electrical connection of the tab part 1112 with external structures (such as the electrode terminal 40).

[0098] The insulation layer 112 is provided on the tab part 1112. According to the structure of the insulation layer 112, the insulation layer 112 can be connected to the tab part 1112 by means of adhesion, or can be connected to the tab part 1112 by solidification or other means. For example, the insulation layer 112 can include an insulating adhesive tape and be connected to the tab part 1112 by means of adhesion. For example, the insulation layer 112 can also include a coating and be connected to the tab part 1112 by means of spraying and solidification. It can be understood that the insulation layer 112 can also include other structures, and is not limited to the above two.

[0099] The insulation layer 112 can be provided on only one side of the tab part 1112, or can be provided on both sides of the tab part 1112. For example, since the current collector 111 is a sheet structure, i.e. the tab part 1112 has two large surfaces in the thickness direction Z of the current collector 111, the insulation layer 112 can cover only one of the two surfaces, or can cover both surfaces.

[0100] The insulating layer 112 is arranged on one side of the tab portion 1112 close to the body portion 1111, that is, the insulating layer 112 is arranged at the root position of the tab portion 1112, so that the root of the tab portion 1112 is less likely to bend or has a smaller bending range; at this time, the part of the tab portion 1112 away from the root can have a larger gap between the body portion 1111 during bending, so that the tab portion 1112 is less likely to be inserted between the adjacent tabs 11 and short-circuit with the body portion 1111.

[0101] The insulating layer 112 can be connected to the tab portion 1112 only, or the insulating layer 112 can be connected to the tab portion 1112 and the body portion 1111 at the same time; at this time, in addition to being able to improve the strength of the tab portion 1112, the insulating layer 112 can also improve the connection strength of the connection part between the tab portion 1112 and the body portion 1111, so as to reduce the risk of tearing of the tab portion 1112.

[0102] In the embodiment, the insulating layer 112 is arranged and covers at least part of the tab portion 1112, so as to increase the strength of the tab portion 1112 through the insulating layer 112, reduce the bending range of the tab portion 1112, and thus reduce the risk of short-circuit caused by the tab portion 1112 being bent and inserted into the gap between the tabs 11, thereby improving the safety performance and stability of the battery monomer 100.

[0103] Referring to FIGS. 6-9, in some embodiments, the tab portion 1112 has at least two and is arranged at intervals along the length direction of the current collector 111; the insulating layer 112 has at least two and is arranged corresponding to the tab portion 1112, and each insulating layer 112 is arranged at intervals along the length direction of the current collector 111.

[0104] The number of the tab portion 1112 is at least two, that is, the number of the tab portion 1112 can be two, or three or more; each tab portion 1112 is arranged at intervals along the length direction X of the current collector 111, so that at least part of each tab portion 1112 can be stacked with each other after the tab 11 is wound.

[0105] The number of the insulating layer 112 is at least two, that is, the number of the insulating layer 112 can be two, or three or more; the insulating layer 112 is arranged corresponding to the tab portion 1112, that is, the insulating layer 112 is arranged on each tab portion 1112, so that the strength of each tab portion 1112 can be strengthened through the insulating layer 112.

[0106] The number of the insulating layers 112 can be consistent with the number of the tab portions 1112, and in this case, the insulating layers 112 correspond to the tab portions 1112 one by one, and each insulating layer 112 covers one tab portion 1112. The number of the insulating layers 112 can also be different from the number of the tab portions 1112, and the number of the insulating layers 112 can be less than the number of the tab portions 1112, in which case, one insulating layer 112 can correspond to two or more insulating layers 112, and the number of the tab portions 1112 corresponding to different insulating layers 112 can also be different. The number of the insulating layers 112 can also be greater than the number of the tab portions 1112, that is, two or more insulating layers 112 can also be arranged along the length direction X of the current collector 111 on one tab portion 1112.

[0107] The insulating layers 112 are arranged at intervals along the length direction of the current collector 111, so that the insulating layers 112 can be mainly used to improve the strength of the tab portions 1112, and the intervals between the insulating layers 112 can reduce the space occupation of the insulating layers 112, thereby reducing the negative impact of the insulating layers 112 on the energy density of the battery monomer 100.

[0108] In the embodiment, the insulating layers 112 are arranged corresponding to the tab portions 1112, so that the insulating layers 112 are mainly used to improve the strength of the tab portions 1112. Meanwhile, the insulating layers 112 are arranged at intervals, so that the part of the insulating layers 112 not covering the tab portions 1112 occupies less space, thereby reducing the negative impact of the insulating layers 112 on the energy density of the battery monomer 100.

[0109] Referring to FIG. 6, in some embodiments, the size of the insulating layer 112 in the length direction of the current collector 111 is less than or equal to the size of the tab portion 1112.

[0110] The size of the insulating layer 112 in the length direction X of the current collector 111 can be less than the size of the tab portion 1112 in the length direction X of the current collector 111, or equal to the size of the tab portion 1112 in the length direction X of the current collector 111, that is, the insulating layer 112 is located within the tab portion 1112 and does not extend beyond the tab portion 1112 in the length direction X of the current collector 111. In this case, the insulating layer 112 can correspond to the tab portion 1112 one by one, that is, one insulating layer 112 is arranged on one tab portion 1112.

[0111] Under the premise that the insulating layer 112 can improve the strength of the tab portion 1112, this arrangement further reduces the space occupation of the insulating layer 112, thereby better reducing the negative impact of the insulating layer 112 on the energy density of the battery monomer 100.

[0112] Optionally, the size of the insulating layer 112 in the length direction X of the current collector 111 is equal to the size of the tab portion 1112 in the length direction X of the current collector 111, so that the insulating layer 112 can better improve the strength of the tab portion 1112 and reduce the negative impact of the insulating layer 112 on the energy density of the battery monomer 100.

[0113] For example, when the tab portion 1112 is in the shape of a rectangular sheet, the shape of the insulating layer 112 can also be rectangular; for example, when the tab portion 1112 is in the shape of a trapezoidal sheet, the shape of the insulating layer 112 can also be trapezoidal.

[0114] The embodiment provides a size range of the insulating layer 112 covering the tab portion 1112 in the length direction of the current collector 111, so that the insulating layer 112 is not easy to extend out of the tab portion 1112 under the premise that the insulating layer 112 can improve the strength of the tab portion 1112, thereby better reducing the occupation of space by the insulating layer 112, and thus better reducing the negative impact of the insulating layer 112 on the energy density of the battery monomer 100.

[0115] Referring to FIG. 6, in some embodiments, the orthographic projection of the insulating layer 112 and the orthographic projection of the tab portion 1112 at least partially overlap on the same projection plane perpendicular to the thickness direction of the current collector 111, and the ratio of the size of the orthographic projection of the insulating layer 112 to the size of the orthographic projection of the tab portion 1112 in the width direction of the current collector 111 is less than or equal to 1:3.

[0116] The projection plane perpendicular to the thickness direction of the current collector 111 refers to a virtual plane perpendicular to the thickness direction of the current collector 111, which is also parallel to the current collector 111.

[0117] The orthographic projection of the insulating layer 112 on the projection plane refers to the projection of the insulating layer 112 on the projection plane in a direction perpendicular to the projection plane, which is also the projection of the insulating layer 112 on the projection plane in the thickness direction Z of the current collector 111. The orthographic projection of the insulating layer 112 on the projection plane reflects the area of the part of the insulating layer 112 covering the tab portion 1112, and the size of the orthographic projection of the insulating layer 112 on the projection plane in the width direction Y of the current collector 111 is the width of the part of the insulating layer 112 covering the tab portion 1112, that is, the size L0 shown in the figure.

[0118] The orthographic projection of the tab portion 1112 on the projection plane refers to the projection of the tab portion 1112 on the projection plane in a direction perpendicular to the projection plane, which is also the projection of the tab portion 1112 on the projection plane in the thickness direction Z of the current collector 111. The size of the orthographic projection of the tab portion 1112 on the projection plane in the width direction Y of the current collector 111 is the length of the tab portion 1112, that is, the size L shown in the figure.

[0119] In the width direction of the current collector 111, the ratio between the size of the orthographic projection of the insulating layer 112 on the projection plane and the size of the orthographic projection of the tab portion 1112 on the projection plane is less than or equal to 1:3, i.e., the width of the orthographic projection of the insulating layer 112 on the projection plane is less than or equal to 1 / 3 of the width of the tab portion 1112. The ratio can be 1:3, 1:4, 1:5, 1:6, or other ratios.

[0120] Since the tab portion 1112 is mainly used to make the pole piece 11 conductive with the circuit outside the electrode assembly 10, in the case where the tab portion 1112 is connected with the external structure, the insulating layer 112 between the tab portion 1112 and the adjacent structure can easily have a negative impact on the conductivity of the tab portion 1112. In the case where the insulating layer 112 completely covers the tab portion 1112, the insulating layer 112 at the part where the tab portion 1112 is connected with the external structure needs to be removed to make the tab portion 1112 have better conductivity, and the removal process of the insulating layer 112 is difficult and complicated.

[0121] Accordingly, the insulating layer 112 only covers part of the tab portion 1112, so that the insulating layer 112 can both improve the strength of the tab portion 1112 and reduce the negative impact of the insulating layer 112 on the conductivity of the tab portion 1112.

[0122] For example, the ratio between the size of the orthographic projection of the insulating layer 112 on the projection plane and the size of the tab portion 1112 is less than or equal to 1:3, so that the insulating layer 112 can both better improve the strength of the tab portion 1112 and reduce the negative impact on the conductivity of the tab portion 1112.

[0123] Some embodiments of the insulating layer 112 cover the size range of the tab portion 1112 in the width direction of the current collector 111, so that the insulating layer 112 can both improve the strength of the tab portion 1112 to reduce the bending amplitude of the tab portion 1112 and reduce the negative impact of the insulating layer 112 on the conductivity of the tab portion 1112.

[0124] In some embodiments, the yield strength of the insulating layer 112 is greater than or equal to 25 MPa (mega pascal).

[0125] The yield strength refers to the stress limit value at which a material begins to have obvious plastic deformation under external force. The yield strength of the insulating layer 112 reflects the ability of the tab portion 1112 to resist deformation under the action of the insulating layer 112. The greater the yield strength of the insulating layer 112, the smaller the bending amplitude of the tab portion 1112 under the same external force, and the tab portion 1112 is less likely to be inserted between the pole pieces 11 and cause short circuit. That is, the higher the yield strength of the insulating layer 112, the lower the risk of the tab portion 1112 being inserted between the pole pieces 11.

[0126] The yield strength of the insulation layer 112 can be 25 MPa, or 35 MPa, 45 MPa, 55 MPa, 65 MPa, 75 MPa, 85 MPa, 95 MPa, 100 MPa, or other values.

[0127] It can be understood that the yield strength of the insulation layer 112 is generally related to the thickness, material, structure, etc. of the insulation layer 112; under the premise that the yield strength of the insulation layer 112 can meet the demand to reduce the insertion of the tab portion 1112 between the tabs 11, the yield strength of the insulation layer 112 can be smaller to reduce the thickness of the insulation layer 112 and reduce the space occupation of the insulation layer 112, and also can reduce the requirements of the insulation layer 112 on the material and structure, reduce the cost and processing difficulty of the insulation layer 112.

[0128] For example, the yield strength of the insulation layer 112 can be 25 MPa, which can not only improve the strength of the tab portion 1112 to make the tab portion 1112 not easy to insert between the tabs 11, but also can reduce the cost and processing difficulty of the insulation layer 112, or can reduce the space occupation of the insulation layer 112.

[0129] The test of the yield strength of the insulation layer 112 can be tested by tensile test, compression test, bending test, etc. Since the insulation layer 112 is mainly used to improve the bending resistance of the tab portion 1112, the bending test is taken as an example, the insulation layer 112 is made into a test sample, a bending force is applied to the test sample to make the test sample deform, and the stress-strain relationship in the process is recorded to determine the yield strength of the insulation layer 112.

[0130] For example, the test sample of the insulation layer 112 can be first made according to the required standard; then the test sample is placed on the two support points of the bending tester and a bending force is applied; the bending force is gradually increased until the test sample reaches the specified deflection or breaks, while the stress-deflection data in the bending process is recorded; the bending yield strength of the material is determined according to the stress-deflection curve.

[0131] The embodiments provide some yield strength ranges of the insulation layer 112, so that the insulation layer 112 can better provide support for the tab portion 1112 to reduce the bending amplitude of the tab portion 1112, thereby better preventing the tab portion 1112 from being inserted between the adjacent tabs 11 to cause short circuit, and better improving the stability and safety of the battery monomer 100.

[0132] In some embodiments in which the yield strength of the insulation layer 112 is greater than or equal to 25 MPa, the yield strength of the insulation layer 112 is less than or equal to 100 MPa.

[0133] The yield strength of the insulation layer 112 is less than or equal to 100 MPa, that is, the yield strength of the insulation layer 112 ranges from 25 MPa to 100 MPa. The yield strength of the insulation layer 112 can be 100 MPa, 95 MPa, 85 MPa, 75 MPa, 65 MPa, 62.5 MPa, 55 MPa, 45 MPa, 35 MPa, 25 MPa, or other values.

[0134] Due to the space and energy density of the battery monomer 100, the space between the electrode assembly 10 and the top cover should not be too large, so in the case of electrical connection between the tab portion 1112 and the external structure (such as the electrode terminal 40), the tab portion 1112 still needs to have a certain bending amplitude. Accordingly, the yield strength of the insulation layer 112 should not be too large to reduce the bending difficulty of the tab portion 1112, and also to reduce the reaction force borne by the structure (such as the main body portion 1111 and the electrode terminal 40) connected to the tab portion 1112.

[0135] For example, the yield strength of the insulation layer 112 can be 62.5 MPa, which can further improve the strength of the tab portion 1112 to make it difficult to insert between the pole pieces 11. This setting can also reduce the cost and processing difficulty of the insulation layer 112, reduce the space occupied by the insulation layer 112, and reduce the stress on the structure connected to the tab portion 1112.

[0136] For example, the yield strength of the insulation layer 112 can be 100 MPa, which can better improve the strength of the tab portion 1112 to make it more difficult to insert between the pole pieces 11, thereby better improving the stability of the battery monomer 100.

[0137] The embodiments further provide some yield strength ranges of the insulation layer 112. On the premise that the insulation layer 112 can provide support for the tab portion 1112, the setting also limits the upper limit of the yield strength of the insulation layer 112 to make the tab portion 1112 have a certain bending ability to meet the electrical connection requirement of the tab portion 1112 and the external structure, and to reduce the negative impact of the tab portion 1112 on the energy density of the battery monomer 100. At the same time, this setting can also reduce the requirements for the material and thickness of the insulation layer 112 to reduce the processing difficulty and cost.

[0138] Referring to FIGS. 6-9, in some embodiments, the thickness of the insulation layer 112 is greater than or equal to 9 μm (microns).

[0139] The thickness of the insulation layer 112 can reflect the strength of the insulation layer 112. When the material of the insulation layer 112 is determined, the greater the thickness of the insulation layer 112, the smaller the bending amplitude of the tab portion 1112, and the better the reinforcing effect of the insulation layer 112 on the tab portion 1112. Referring to FIG. 7, the thickness of the insulation layer 112 is the size of the insulation layer 112 in the thickness direction Z of the current collector 111, that is, the size W shown in the figure.

[0140] The thickness of the insulation layer 112 is greater than or equal to 9 μm. When the thickness of the insulation layer 112 is uniform or substantially uniform at each location, the thickness of the insulation layer 112 refers to the thickness dimension of the insulation layer 112 at any location, which is greater than or equal to 9 μm at this time. When the thickness of the insulation layer 112 is not uniform, the thickness of the thinnest part of the insulation layer 112 should be greater than or equal to 9 μm.

[0141] The thickness of the insulation layer 112 is greater than or equal to 9 μm. For example, the thickness of the insulation layer 112 can be 9 μm, 13 μm, 17 μm, 21 μm, 25 μm, 30 μm, or other values.

[0142] For example, the thickness of the insulation layer 112 is 9 μm. At this time, the insulation layer 112 has a certain strength and can provide support for the tab portion 1112, so that the bending amplitude of the tab portion 1112 is not too large, so that the tab portion 1112 is not easily inserted between the pole pieces 11. 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.

[0143] The present embodiment provides some thickness ranges of the insulation layer 112. Since the thickness of the insulation layer 112 is positively correlated with the support performance of the insulation layer 112, the thickness of the insulation layer 112 is greater than or equal to 9 μm, so as to limit the lower limit of the support performance that the insulation layer 112 can provide for the tab portion 1112, so that the tab portion 1112 is not easily inserted between the pole pieces 11.

[0144] In some embodiments, the thickness of the insulation layer 112 ranges from 9 μm to 30 μm.

[0145] The thickness of the insulation layer 112 is less than or equal to 30 μm. When the thickness of the insulation layer 112 is uniform or substantially uniform at each location, the thickness of the insulation layer 112 refers to the thickness dimension of the insulation layer 112 at any location, which is less than or equal to 30 μm at this time. When the thickness of the insulation layer 112 is not uniform, the thickness of the thickest part of the insulation layer 112 should be less than or equal to 30 μm.

[0146] The thickness of the insulation layer 112 is less than or equal to 30 μm. For example, the thickness of the insulation layer 112 can be 30 μm, 25 μm, 21 μm, 17 μm, 13 μm, 9 μm or other values. The thickness of the insulation layer 112 is less than or equal to 30 μm. For example, the thickness of the insulation layer 112 can be 30 μm, 25 μm, 21 μm, 17 μm, 13 μm, 9 μm or other values.

[0147] The thickness of the insulation layer 112 is less than or equal to 30 μm. For example, the thickness of the insulation layer 112 can be 30 μm, 25 μm, 21 μm, 17 μm, 13 μm, 9 μm or other values. The thickness of the insulation layer 112 is less than or equal to 30 μm. For example, the thickness of the insulation layer 112 can be 30 μm, 25 μm, 21 μm, 17 μm, 13 μm, 9 μm or other values.

[0148] For example, the thickness of the insulation layer 112 is 30 μm. In this case, the insulation layer 112 has higher strength and can better support the tab portion 1112, so that the tab portion 1112 is difficult to insert between the pole pieces 11.

[0149] For example, the thickness of the insulation layer 112 is 19.5 μm. In this case, the insulation layer 112 has higher strength to support the tab portion 1112, and can also reduce the negative impact on the energy density of the battery monomer 100.

[0150] The embodiment further provides a thickness range of the insulation layer 112. On the premise that the insulation layer 112 can support the tab portion 1112, the thickness of the insulation layer 112 is limited to an upper limit, so that the tab portion 1112 has a certain bending ability to meet the demand of electrical connection between the tab portion 1112 and the external structure, and can reduce the negative impact of the tab portion 1112 on the energy density of the battery monomer 100. At the same time, the space occupation of the insulation layer 112 is reduced, and the negative impact of the insulation layer 112 on the energy density of the battery monomer 100 is reduced.

[0151] Referring to FIGS. 6-9, in some embodiments, the main body portion 1111 includes two end faces 1111a opposite to each other along the width direction of the current collector 111, and the main body portion 1111 further includes two side faces 1111b opposite to each other along the thickness direction of the current collector 111, and the tab portion 1112 is formed on the end face 1111a; the pole piece 11 further includes an active material layer 113 arranged on the side face 1111b, and the active material layer 113 covers at least part of the side face 1111b; and the orthographic projection of the insulation layer 112 and the orthographic projection of the side face 1111b at least partially overlap on the same projection plane perpendicular to the thickness direction of the current collector 111.

[0152] The body part 1111 includes an end surface 1111a and a side surface 1111b. Among them, the end surface 1111a refers to the two surfaces of the body part 1111 located at the opposite ends in the width direction Y of the current collector 111, and the end surface 1111a is also the surface formed after the die cutting of the tab 11, and the tab part 1112 is formed on the end surface 1111a; the side surface 1111b refers to the two surfaces of the body part 1111 located at the opposite sides in the thickness direction Z of the current collector 111, and the active substance is usually formed on the side surface 1111b.

[0153] The tab part 1112 is formed on the end surface 1111a, and the tab part 1112 extends away from the body part 1111 in the width direction Y of the current collector 111 from the end surface 1111a of the body part 1111.

[0154] The active substance layer 113 refers to a layered structure formed on the side surface 1111b of the body part 1111 and used to participate in the electrochemical reaction. According to the polarity of the tab 11, the material of the active substance layer 113 can include lithium manganate, lithium cobaltate, lithium nickel cobalt manganate, etc. The material of the active substance layer 113 can also include natural graphite, artificial graphite, etc.

[0155] The active substance layer 113 can cover at least part of the corresponding side surface 1111b, that is, the active substance layer 113 can cover only part of the corresponding side surface 1111b, or can completely cover the entire corresponding side surface 1111b. Because the area of the active substance layer 113 is positively correlated with the charge and discharge performance of the tab 11, the active substance layer 113 should cover as much of the corresponding side surface 1111b as possible, that is, the active substance layer 113 should cover most or all of the corresponding side surface 1111b. Because of the influence of the processing technology, the active substance layer 113 is usually not easy to completely cover the corresponding side surface 1111b, so in the case that the active substance layer 113 only covers part of the corresponding side surface 1111b, the active substance layer 113 should cover as much of the corresponding side surface 1111b as possible, and the area of the active substance layer 113 not covered should be small.

[0156] The projection plane perpendicular to the thickness direction of the current collector 111 refers to a virtual plane perpendicular to the thickness direction of the current collector 111, which is also parallel to the current collector 111; the orthographic projection of the insulating layer 112 on the projection plane refers to the projection of the insulating layer 112 on the projection plane in the direction perpendicular to the projection plane, which is also the projection of the insulating layer 112 on the projection plane in the thickness direction Z of the current collector 111; the orthographic projection of the side surface 1111b on the projection plane refers to the projection of the side surface 1111b on the projection plane in the direction perpendicular to the projection plane, which is also the projection of the side surface 1111b on the projection plane in the thickness direction Z of the current collector 111.

[0157] The orthogonal projection of the insulating layer 112 at least partially overlaps with the orthogonal projection of the side surface 1111b, that is, the insulating layer 112 is connected to the main body part 1111 and / or the active material layer in addition to the tab part 1112. For example, when the active material layer 113 completely covers the corresponding side surface 1111b, the insulating layer 112 can also be connected to the active material layer 113; for example, when the active material layer 113 only covers part of the corresponding side surface 1111b, the insulating layer 112 can be connected only to the side surface 1111b of the main body part 1111; for example, when the active material layer 113 only covers part of the corresponding side surface 1111b, the insulating layer 112 can be connected to both the corresponding side surface 1111b and the active material layer 113; for example, when the active material layer 113 only covers part of the corresponding side surface 1111b, the insulating layer 112 can be connected only to the active material layer 113, and the part of the side surface 1111b not covered by the active material layer 113 is not located on the side of the side surface 1111b close to the insulating layer 112.

[0158] The insulating layer 112 can be connected to the side surface 1111b and / or the active material layer 113 by adhesion, curing or other means, depending on the material of the insulating layer 112.

[0159] In the embodiment, the insulating layer 112 can cover not only the tab part 1112 but also part of the side surface 1111b of the main body part 1111 and / or the active material layer 113, so that the insulating layer 112 can not only provide support for the tab part 1112 but also improve the connection strength between the tab part 1112 and the main body part 1111, thereby preventing the tab part 1112 from being easily torn at the connection site with the main body part 1111, and further improving the safety and stability of the battery monomer 100.

[0160] Referring to FIGS. 6-9, in some embodiments, the insulating layer 112 includes two sub-insulating layers 1121 corresponding to the two side surfaces 1111b, the sub-insulating layer 1121 including a first part 1121a covering at least part of the tab part 1112 and a second part 1121b connected to the first part 1121a, and the orthogonal projection of the second part 1121b at least partially overlaps with the orthogonal projection of the side surface 1111b on the same projection plane perpendicular to the thickness direction of the current collector 111.

[0161] The sub-insulating layer 1121 refers to a part of the insulating layer 112, and there are two sub-insulating layers 1121 which can be combined to form the insulating layer 112; the two sub-insulating layers 1121 can be arranged on opposite sides of the current collector 111 and cover the two side surfaces 1111b of the tab part 1112, thereby improving the strength of the tab part 1112.

[0162] The sub-insulating layer 1121 includes a first part 1121a and a second part 1121b. The first part 1121a is a part of the sub-insulating layer 1121, and covers at least part of the tab part 1112, i.e., the first part 1121a is connected to the tab part 1112, thereby improving the strength of the tab part 1112 and reducing the bending amplitude of the tab part 1112. According to the material of the sub-insulating layer 1121, the first part 1121a can be bonded to the tab part 1112 or connected to the tab part 1112 by curing or the like.

[0163] The projection plane perpendicular to the thickness direction of the current collector 111 refers to a virtual plane perpendicular to the thickness direction of the current collector 111, and the virtual plane is also parallel to the current collector 111. The second part 1121b is a part of the sub-insulating layer 1121, and the orthographic projection of the second part 1121b on the projection plane refers to the projection of the second part 1121b on the projection plane in a direction perpendicular to the projection plane, and also refers to the projection of the second part 1121b on the projection plane in the thickness direction Z of the current collector 111.

[0164] The orthographic projection of the second part 1121b at least partially overlaps the orthographic projection of the side surface 1111b, i.e., the second part 1121b is connected to the side surface 1111b and / or the active material layer 113. According to the coverage area and position of the active material layer 113, the second part 1121b can be connected to only the side surface 1111b or the active material layer 113, or can be connected to both the side surface 1111b and the active material layer 113. According to the material of the sub-insulating layer 1121, the second part 1121b can be bonded to the side surface 1111b and / or the active material layer 113, or can be connected to the side surface 1111b and / or the active material layer 113 by curing or the like. The second part 1121b is connected to the first part 1121a, and the second part 1121b can be integrally formed with the first part 1121a, or the second part 1121b can be connected to the first part 1121a by bonding, curing or the like.

[0165] It can be understood that, because the first part 1121a is connected to the second part 1121b, and the second part 1121b is connected to the side surface 1111b and / or the active material layer 113, in the case where the first part 1121a only covers part of the tab part 1112, the first part 1121a can at least cover the part of the tab part 1112 connected to the first main body part 1111. At this time, the first part 1121a and the second part 1121b can play a role of improving the connection strength of the connection part between the tab part 1112 and the main body part 1111.

[0166] The embodiment provides specific structures of the insulation layer 112, so that the insulation layer 112 is formed by two sub-insulation layers 1121 connected to each other, the sub-insulation layer 1121 includes a first part 1121a and a second part 1121b, the first part 1121a covers at least part of the tab part 1112, and the second part 1121b covers part of the side surface 1111b, so that the insulation layer 112 can improve the strength of the tab part 1112 and the connection strength between the tab part 1112 and the main body part 1111.

[0167] Referring to FIGS. 6 and 8, in some embodiments in which the active material layer 113 does not completely cover the corresponding side surface 1111b, the active material layer 113 covers part of the corresponding side surface 1111b, and forms a blank area 1111c on the side of the side surface 1111b close to the tab part 1112, and the second part 1121b covers at least part of the blank area 1111c.

[0168] 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 tab part 1112. Referring to FIG. 8, the area corresponding to the size L2 shown in the figure is the blank area 1111c.

[0169] 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 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.

[0170] Covering the blank area 1111c by the second part 1121b can reduce the area of the first main body part 1111 directly in contact with the electrolyte, thereby reducing damage of the electrolyte to the first main body part 1111 and reducing the occurrence of short circuit and the like of the battery monomer 100.

[0171] In the embodiment, the second part 1121b can cover at least part of the blank area 1111c to protect the main body part 1111, and also reduce the area of the main body part 1111 exposed to the outside, thereby reducing the occurrence of short circuit and the like and improving the safety performance of the battery monomer 100.

[0172] Referring to FIGS. 6 and 8, in some embodiments in which the second part 1121b covers the blank area 1111c, the sub-insulation layer 1121 further includes a third part 1121c connected to the second part 1121b on the side opposite to the first part 1121a, the second part 1121b covers the blank area 1111c, and the third part 1121c covers part of the active material layer 113.

[0173] 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, i.e., the first part 1121a, the second part 1121b, and the third part 1121c are arranged in sequence along the width direction Y of the current collector 111; the third part 1121c can be integrally formed with the second part 1121b, or can be connected to the second part 1121b by adhesion, curing, or the like.

[0174] 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 1111 and better improve the safety performance of the battery monomer 100.

[0175] According to the structure of the third part 1121c, the third part 1121c can be connected to the active material layer 113 by adhesion, or can be connected to the active material layer 113 by curing or other means.

[0176] In the case where the sub-insulating layer 1121 does not cover the active material layer 113, the second part 1121b of the sub-insulating layer 1121 is difficult to seal and gap-free adhere to the active material layer 113 due to the influence of the processing process, and the gap between the second part 1121b and the active material layer 113 is easy to cause the main body part 1111 to be exposed and cause short circuit and the like.

[0177] Accordingly, the sub-insulating layer 1121 of the embodiment 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.

[0178] Referring to FIGS. 6 and 8, in some embodiments in which the third part 1121c covers the active material layer 113, the size range of the orthographic projection of the third part 1121c on a projection plane perpendicular to the thickness direction of the current collector 111 is 0.1 mm to 1 mm.

[0179] The projection plane perpendicular to the thickness direction of the current collector 111 refers to a virtual plane perpendicular to the thickness direction of the current collector 111, which is also parallel to the current collector 111; the orthographic projection of the third part 1121c on the projection plane refers to the projection of the third part 1121c on the projection plane in a direction perpendicular to the projection plane, which is also the projection of the third part 1121c on the projection plane in the thickness direction Z of the current collector 111.

[0180] In the case where the third portion 1121c covers the active material layer 113, the size of the third portion 1121c in the orthogonal projection of the third portion 1121c on the projection face in the width direction Y of the current collector 111 is the width of the third portion 1121c; the size shown as L3 in FIG. 8 is the size of the third portion 1121c in the orthogonal projection of the third portion 1121c on the projection face in the width direction Y of the current collector 111, which can be 0.1 mm, or 0.1 mm, 0.2 mm, 0.4 mm, 0.55 mm, 0.6 mm, 0.8 mm, 1 mm, or other values.

[0181] The width of the third portion 1121c is positively correlated with the area of the active material layer 113 covered by the third portion 1121c. The greater the width of the third portion 1121c, the greater the area of the active material layer 113 covered by the third portion 1121c, the better the stability of the connection of the third portion 1121c to the active material layer 113, the less likely the third portion 1121c to fall off, and the less likely the blank area 1111c of the main body portion 1111 to be damaged due to contact with the electrolyte. Since the charge and discharge capacity of the active material layer 113 is positively correlated with the area of the active material layer 113 that can be in contact with the electrolyte, the greater the width of the third portion 1121c, the worse the charge and discharge capacity of the active material layer 113.

[0182] Accordingly, the width of the third portion 1121c is in the range of 0.1 mm to 1 mm, so that the third portion 1121c can be stably connected to the active material layer 113 and the negative impact of the third portion 1121c on the charge and discharge capacity of the active material layer 113 can be reduced.

[0183] For example, the size of the third portion 1121c in the orthogonal projection of the third portion 1121c on the projection face in the width direction Y of the current collector 111 can be 0.1 mm, and under the premise that the third portion 1121c can be connected to the active material layer 113, this setting can reduce the area of the active material layer 113 covered by the third portion 1121c, thereby reducing the negative impact of the third portion 1121c on the charge and discharge capacity of the active material layer 113.

[0184] For example, the size of the third portion 1121c in the orthogonal projection of the third portion 1121c on the projection face in the width direction Y of the current collector 111 can be 0.55 mm, and in this case, the third portion 1121c can be stably connected to the active material layer 113, so that the blank area 1111c is less likely to be in contact with the electrolyte. At the same time, this setting can also reduce the area of the active material layer 113 covered by the third portion 1121c.

[0185] For example, the third part 1121c can have a size of 1 mm in the width direction Y of the current collector 111 in the orthogonal projection on the projection surface, so that the third part 1121c can be more stably connected to the active material layer 113, and the third part 1121c is less likely to be separated from the active material layer 113 under the infiltration of the electrolyte, so as to better improve the connection stability of the third part 1121c, reduce the risk of damage of the main body part 1111 caused by the contact of the electrolyte with the blank area 1111c, and thus better play a role in protecting the main body part 1111.

[0186] In some embodiments, the third part 1121c has a size in the width direction Y of the current collector 111, and the size of the third part 1121c in the width direction Y of the current collector 111 is smaller under the premise that the third part 1121c can cover the active material layer 113, so as to reduce the negative influence of the third part 1121c on the charge and discharge capacity of the active material layer 113.

[0187] Referring to FIGS. 6 and 9, in some embodiments in which the active material layer 113 completely covers the corresponding side surface 1111b, the active material layer 113 completely covers the corresponding side surface 1111b, and the second part 1121b covers part of the active material layer 113.

[0188] The active material layer 113 completely covers the corresponding side surface 1111b, so that the contact area between the active material layer 113 and the electrolyte is larger, and the charge and discharge performance of the active material layer 113 is better. At the same time, there is no blank area 1111c on the side surface 1111b, and the main body part 1111 is less likely to contact the electrolyte, so as to reduce the damage of the electrolyte to the main body part 1111 and improve the service life of the main body part 1111.

[0189] In the case where the active material layer 113 completely covers the corresponding side surface 1111b, there is no blank area 1111c on the side surface 1111b, and the sub-insulating layer 1121 can be directly connected to the active material layer 113, i.e., the second part 1121b covers part of the active material layer 113.

[0190] Since the first part 1121a is connected to the tab part 1112, and the second part 1121b is connected to the active material layer 113, the first part 1121a and the second part 1121b can also play a role in strengthening the connection strength between the tab part 1112 and the main body part 1111, so as to reduce the risk of tearing of the tab part 1112 and the main body part 1111.

[0191] In this embodiment, the active material layer 113 completely covers the side surface 1111b of the main body part 1111, so that the active material layer 113 has a larger contact area with the electrolyte, thereby improving the charge and discharge capacity of the active material layer 113; and the second part 1121b covers part of the active material layer 113, so that the insulating layer 112 can improve the strength of the tab part 1112 and the connection strength of the connection part between the tab part 1112 and the main body part 1111.

[0192] Referring to FIGS. 6 and 9, in some embodiments in which the active material layer 113 completely covers the corresponding side surface 1111b, the size of the orthographic projection of the second part 1121b on the projection plane perpendicular to the thickness direction of the current collector 111 ranges from 0.1 mm to 1 mm.

[0193] In the case where the active material layer 113 completely covers the corresponding side surface 1111b and the second part 1121b covers the active material layer 113, the size of the orthographic projection of the second part 1121b on the projection plane in the width direction Y of the current collector 111 is the width of the second part 1121b; the size L2 shown in FIG. 9 is the size of the orthographic projection of the second part 1121b on the projection plane in the width direction Y of the current collector 111, which can be 0.1 mm, 0.1 mm, 0.2 mm, 0.4 mm, 0.55 mm, 0.6 mm, 0.8 mm, 1 mm or other values.

[0194] The width of the second part 1121b is positively correlated with the area of the active material layer 113 covered by the second part 1121b. The greater the width of the second part 1121b, the greater the area of the active material layer 113 covered by the second part 1121b, the better the stability of the connection between the second part 1121b and the active material layer 113, and the less likely the second part 1121b is to fall off. Since the charge and discharge capacity of the active material layer 113 is positively correlated with the area of the active material layer 113 that can be in contact with the electrolyte, the greater the width of the second part 1121b, the worse the charge and discharge capacity of the active material layer 113.

[0195] Therefore, the width of the second part 1121b ranges from 0.1 mm to 1 mm, so that the second part 1121b can be stably connected to the active material layer 113 and can reduce the negative impact of the second part 1121b on the charge and discharge capacity of the active material layer 113.

[0196] For example, the size of the orthographic projection of the second part 1121b on the projection plane in the width direction Y of the current collector 111 can be 0.1 mm, which can reduce the area of the active material layer 113 covered by the second part 1121b and thereby reduce the negative impact of the second part 1121b on the charge and discharge capacity of the active material layer 113, on the premise that the second part 1121b can be connected to the active material layer 113.

[0197] For example, the size of the second part 1121b in the width direction Y of the current collector 111 can be 0.55 mm, so that the second part 1121b can be stably connected to the active material layer 113, and the second part 1121b is not easy to fall off; at the same time, the setting can also reduce the area of the second part 1121b covering the active material layer 113.

[0198] For example, the size of the second part 1121b in the width direction Y of the current collector 111 can be 1 mm, so that the second part 1121b can be more stably connected to the active material layer 113, and the second part 1121b is not easy to separate under the infiltration of the electrolyte, so as to better improve the connection stability of the second part 1121b, thereby better playing a role in improving the connection strength between the tab part 1112 and the main body part 1111.

[0199] The size of the second part 1121b in the width direction Y of the current collector 111 is provided in some embodiments, under the premise that the second part 1121b can be connected to the active material layer 113, the size of the second part 1121b in the width direction Y of the current collector 111 is small, so as to reduce the negative influence of the second part 1121b on the charge and discharge capacity of the active material layer 113.

[0200] In some embodiments, the tab part 1112 has at least two and is arranged at intervals along the length direction of the current collector 111; the insulating layer 112 has one, and the insulating layer 112 covers at least one tab part 1112.

[0201] The number of the tab part 1112 is at least two, that is, the number of the tab part 1112 can be two, or three or more; each tab part 1112 is arranged at intervals along the length direction X of the current collector 111, so that at least part of each tab part 1112 can be stacked with each other after the tab sheet 11 is wound.

[0202] The number of the insulating layer 112 is one, and in the case that the tab part 1112 has multiple, according to the needs, the insulating layer 112 can cover only one or several of the multiple tab parts 1112, and because each tab part 1112 is arranged along the length direction X of the current collector 111, the size of the insulating layer 112 in the length direction X of the current collector 111 can be small; the insulating layer 112 can also cover each tab part 1112, and the size of the insulating layer 112 in the length direction X of the current collector 111 is large.

[0203] The insulating layer 112 has one and covers at least one tab portion 1112, so that the insulating layer 112 can improve the strength of the tab portion 1112 and reduce the difficulty of processing and setting of the insulating layer 112; for example, only one insulating layer 112 is arranged on each tab portion 1112 in the processing process, and no other processing treatment is required for the insulating layer 112.

[0204] In the embodiment, the insulating layer 112 has one, and one insulating layer 112 can cover one or more tab portions 1112, so that the insulating layer 112 can increase the strength of the tab portion 1112 and reduce the bending amplitude of the tab portion 1112, and reduce the difficulty of processing and setting of the insulating layer 112.

[0205] Referring to FIGS. 6, 8, and 10, in some embodiments, the insulating layer 112 includes a substrate layer 1121d and an adhesive layer 1121e arranged on the substrate layer 1121d, the adhesive layer 1121e is arranged on the side of the substrate layer 1121d facing the current collector 111, and the adhesive layer 1121e is connected to at least the tab portion 1112.

[0206] The substrate layer 1121d refers to a layered structure in the sub-insulating layer 1121 mainly used to provide a fixed basis, which can be used to provide a fixed basis for the adhesive layer 1121e, improve the strength of the corresponding tab portion 1112, and provide protection for the corresponding main body portion 1111 or active material layer 113; according to the function 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, etc.

[0207] The adhesive layer 1121e refers to a layered structure in the sub-insulating layer 1121 mainly used for fixing, which is arranged on the side of the substrate layer 1121d facing the current collector 111 to fix the substrate layer 1121d on the current collector 111; in the case where the insulating layer 112 is only arranged on the tab portion 1112, the adhesive layer 1121e is adhered to the tab portion 1112; in the case where the insulating layer 112 also covers part of the side surface 1111b and / or part of the active material layer 113, the adhesive layer 1121e is also adhered to the side surface 1111b and / or the active material layer 113; 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 by light curing, heat curing or other curing methods.

[0208] In the case where the sub-insulating layer 1121 is connected to the tab portion 1112, the adhesive connection can bond the base material layer 1121d to the tab portion 1112, and at this time, the pressure applied to the tab portion 1112 can also be transmitted to the adhesive layer 1121e and the base material layer 1121d, so as to improve the strength of the tab portion 1112 through the adhesive layer 1121e and the base material layer 1121d.

[0209] The embodiment provides a structure of some sub-insulating layers 1121, so that the sub-insulating layer 1121 includes an adhesive layer 1121e and a base material layer 1121d, so that the base material layer 1121d can be connected to the tab portion 1112 through the adhesive layer 1121e, so that the base material layer 1121d can provide support for the tab portion 1112 and improve the strength of the tab portion 1112, and so that the base material layer 1121d can also play a role in protecting the tab portion 1112.

[0210] Referring to FIG. 5, in some embodiments, the battery cell 100 includes an electrode assembly 10, and the electrode assembly 10 includes a tab 13, and the tab 13 includes at least two tab portions 1112 arranged in a stack.

[0211] The tab 13 refers to a structure in the electrode assembly 10 for making the electrode sheet 11 conductive to the circuit outside the electrode assembly 10, and the tab 13 can be connected to the electrode terminal 40; the electrode assembly 10 can be formed by winding, stacking, etc. of the electrode sheet 11; the electrode assembly 10 can include a positive electrode sheet, a separator 12, and a negative electrode sheet, and the positive electrode sheet, the separator 12, the negative electrode sheet, and the separator 12 can be arranged in a stack.

[0212] The tab 13 can include at least two tab portions 1112 arranged in a stack, that is, the tab 13 can include only two tab portions 1112, or can include three or more tab portions 1112; because the electrode assembly 10 includes the electrode sheet 11 arranged in a stack or wound, the electrode sheet 11 arranged in a stack or wound can make at least part of the tab portions 1112 arranged along the length direction X of the electrode sheet 11 in a stack, so as to form the tab 13.

[0213] For example, the electrode assembly 10 can be formed by winding of the electrode sheet 11, at this time, the positive electrode sheet, the separator 12, the negative electrode sheet, and the separator 12 are stacked to form a composite, and the composite is wound to form the electrode assembly 10; at this time, the winding of the electrode sheet 11 can make at least part of the tab portions 1112 on the other electrode sheet 11 stacked to form the tab 13.

[0214] For example, the electrode assembly 10 can be formed by stacking of the electrode sheet 11, at this time, the positive electrode sheet and the negative electrode sheet are alternately stacked in sequence, and the separator 12 is arranged between the adjacent two electrode sheets 11; at this time, the length of each electrode sheet 11 can be set according to the size of the electrode assembly 10, and the tab portions 1112 on each electrode sheet 11 are stacked with the electrode sheet 11 to form the tab 13.

[0215] In the case where the tab 13 is connected to the electrode terminal 40, the tab 13 is gradually deformed in the process of covering the end cover 30 on the shell 20 and connecting the end cover 30 to the shell 20 after the electrode assembly 10 is loaded into the shell 20. Since the insulating layer 112 is arranged on each tab portion 1112, the overall strength of the tab 13 is improved, and thus the deformation range of the tab 13 is limited, and the tab 13 is not easily inserted between the adjacent electrode plates 11 of the electrode assembly 10, thereby reducing the risk of short circuit between the tab 13 and the adjacent positive or negative electrode plate.

[0216] The embodiment provides a specific structure of the tab 13 of the electrode assembly 10, so that the tab 13 includes at least two tab portions 1112 arranged in a stack, and the insulating layer 112 is arranged on each tab portion 1112. At this time, the tab 13 of the electrode assembly 10 can have higher strength under the support of the plurality of insulating layers 112, so that the tab 13 is more difficult to be inserted between the electrode plates 11.

[0217] Referring to FIGS. 2 and 3, in some embodiments, the battery cell 100 is a cylindrical battery cell.

[0218] The battery cell 100 can be a cylindrical battery cell 100. At this time, the tab 13 of the electrode assembly 10 can be processed by a rubbing method. That is, after the tab portions 1112 are stacked to form the tab 13, the rotating tab 13 can be rubbed by ultrasonic rubbing, mechanical rubbing or other methods by using a rubbing device, so that the tab 13 forms a structure similar to a flat plane at one end of the electrode assembly 10.

[0219] In the process of rubbing the tab 13, only part of each tab portion 1112 can be pressed and rubbed, or the entire tab portion 1112 can be rubbed.

[0220] In the process of rubbing the tab 13, the tab 13 is continuously subjected to pressure. Since the insulating layer 112 is arranged on each tab portion 1112, the overall strength of the tab 13 is improved. In the process of continuously pressing the tab 13, the deformation range of the tab 13 is limited, and the tab 13 is not easily inserted between the adjacent electrode plates 11 of the electrode assembly 10, thereby reducing the risk of short circuit between the tab 13 and the adjacent positive or negative electrode plate.

[0221] The embodiment provides a specific structure of the tab 13 of the electrode assembly 10, so that at least part of each tab portion 1112 is rubbed to form the tab 13, so that the electrode assembly 10 can meet the needs of the cylindrical battery cell 100 and the like.

[0222] Referring to FIGS. 11 and 12, in other embodiments, the battery cell 100 can also be a square shell battery cell.

[0223] In some embodiments, for the sticking process of the insulating layer 112, the sticking process of the insulating layer 112 can be arranged after the die-cutting process of the pole piece 11; for example, a sticking module can be added to the die-cutting process, the pole piece 11 is conveyed at a speed of 10-100 m / min and die-cutting is performed, and after the pole piece 11 is die-cut, the die-cut pole piece 11 is continuously stuck by the sticking module to bond the insulating layer 112 to the tab portion 1112.

[0224] In some embodiments, the preparation process of the positive pole piece is as follows:

[0225] The material of the active material layer 113 of the positive pole piece includes active material lithium iron phosphate (LiFePO4, LFP), binder polyvinylidene fluoride (PVDF), and conductive carbon black (Super P), which are uniformly mixed in a ratio of lithium iron phosphate: polyvinylidene fluoride: conductive carbon black = 95:3:2 to obtain a first mixed slurry.

[0226] The dispersion solvent is 1-methyl-2-pyrrolidone (NMP), and the first mixed slurry is dispersed using the dispersion solvent to obtain a positive pole slurry.

[0227] The positive pole slurry is applied to the two side surfaces 1111b of the aluminum foil (current collector 111 of the positive pole piece), and is sequentially subjected to drying, rolling, die-cutting, and slitting.

[0228] Two pieces of insulating adhesive paper are used as the sub-insulating layer 1121, and are respectively attached to the tab portions 1112 on the two sides of the aluminum foil to form the insulating layer 112.

[0229] In some embodiments, the preparation process of the negative pole piece is as follows:

[0230] The material of the active material layer 113 of the negative pole piece includes active material graphite, binder styrene butadiene rubber (SBR), and conductive carbon black, which are uniformly mixed in a ratio of graphite: styrene butadiene rubber: conductive carbon black = 94:4:2 to obtain a second mixed slurry.

[0231] The dispersion solvent is ionized water, and the second mixed slurry is dispersed using the dispersion solvent to obtain a negative pole slurry.

[0232] The negative pole slurry is applied to the two side surfaces 1111b of the copper foil (current collector 111 of the negative pole piece), and is sequentially subjected to drying, rolling, die-cutting, and slitting to obtain the negative pole piece.

[0233] In some embodiments, the base film of the separator 12 is polyethylene, and the base film is sequentially coated with an adhesive coating layer of 2 μm and a PCS coating layer of 1.5 μm, wherein the PCS coating layer is a polymer coating layer, which can include polyvinylidene fluoride (PVDF).

[0234] In some embodiments, the electrolyte is a carbonate-based electrolyte, the solute of the electrolyte is lithium hexafluorophosphate (LFPF), and the concentration of the solute is 1M (molar concentration).

[0235] In some embodiments, the preparation process of the electrode assembly 10 is as follows:

[0236] The prepared positive electrode sheet, the separator 12 and the negative electrode sheet are wound, and then the electrode assembly 10 is obtained through heat pressing and shaping.

[0237] In some embodiments, the assembly process of the battery cell 100 is as follows:

[0238] The anode sheet 11, the separator 12 and the cathode sheet 11 are stacked in sequence and wound to obtain the electrode assembly 10, wherein the anode sheet 11 is in the inner layer, and the anode sheet 11 is larger than the cathode sheet 11 in length and width direction, and the length of the separator 12 exceeds that of the anode sheet 11; then, the electrode assembly 10 after winding is sequentially shaped, heat pressed, put into the shell, welded, baked, injected, formed, aged and the like, to complete the assembly of the battery cell 100.

[0239] In some embodiments, the battery cell 100 includes the electrode sheet 11, and the electrode sheet 11 includes the current collector 111, the active material layer 113 and the insulating layer 112.

[0240] The current collector 111 includes a main body part 1111, and the main body part 1111 includes two side surfaces 1111b and two end surfaces 1111a; the current collector 111 further includes a tab part 1112 connected to the end surface 1111a.

[0241] The active material layer 113 is arranged on and covers the side surface 1111b.

[0242] The insulating layer 112 is connected to and covers the opposite two sides of the tab part 1112, and the insulating layer 112 is arranged at intervals in the length direction X of the current collector 111, and the insulating layer 112 is arranged one-to-one corresponding to the tab part 1112; the size of the insulating layer 112 in the length direction X of the current collector 111 is the same as the size of the tab part 1112 in the length direction X of the current collector 111; the size of the insulating layer 112 in the width direction Y of the current collector 111 is 1 / 3 of the size of the tab part 1112 in the width direction Y of the current collector 111.

[0243] In the second aspect, some embodiments of the battery device 1000 include the battery cell 100 provided by some embodiments of the first aspect; in the battery device 1000, the burr of the electrode sheet 11 is not easy to pierce the adjacent separator 12 to cause short circuit, so that the battery device 1000 can have higher stability.

[0244] In a third aspect, some embodiments of the present application also provide an energy storage device 1 comprising the battery cell 100 provided by some embodiments of the first aspect, or the battery device 1000 provided by some embodiments of the second aspect.

[0245] The energy storage device 1 comprises one or more battery clusters to improve the voltage and capacity of the energy storage device 1. The battery cluster can comprise a plurality of battery devices 1000, which are connected in series by busbar components to improve the voltage of the energy storage device 1. When the energy storage device 1 comprises a plurality of battery clusters, the plurality of battery clusters are connected in parallel to improve the capacity of the energy storage device 1.

[0246] The energy storage device 1 can be used in energy storage power stations, wind power systems, solar power systems, mobile power systems, or temporary power supply systems, etc. The energy storage device 1 can store electrical energy as needed and output electrical energy at the appropriate time. For example, the energy storage device 1 can store electrical energy during the off-peak period of electricity consumption, and provide electrical energy for related users or electrical equipment during the peak period of electricity consumption. 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.

[0247] In some embodiments, the energy storage device 1 is an energy storage container or an energy storage cabinet.

[0248] In some embodiments, the energy storage device 1 can comprise a cabinet body and one or more battery clusters, which are accommodated in the cabinet body.

[0249] In some embodiments, the energy storage device 1 can comprise a thermal management module, a master control module, a general control module, a power distribution module, and a fire-fighting module, etc.

[0250] As an example, the thermal management module can comprise a liquid cooling unit, which provides cooling liquid for adjusting the temperature of the battery cell 100 to each battery device 1000 through a pipeline.

[0251] 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 the current, voltage, power, or temperature, etc. of the battery cluster. For example, the charging and discharging current, voltage, etc. of the battery cluster can be controlled. The master control module comprises a slave battery management unit (SBMU), a fuse switch, etc.

[0252] As an example, the master control module can be used as a battery management unit of the energy storage device 1 to monitor and manage the energy storage device 1. The master 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, voltage, and the like of the energy storage device 1 can be controlled. As an example, the master control module includes an insulation monitoring module IMM (Insulation Monitoring Module, IMM), a master battery management unit MBMU (Master Battery Management Unit, MBMU), an Ethernet ETH (EtherNet, ETH), and an optical fiber conversion module.

[0253] As an example, the fire control module includes a control panel, a detector, an alarm device, and the like, which are used for detecting, alarming, or extinguishing the energy storage system.

[0254] 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.

[0255] In a fourth aspect, referring to FIG. 13, some embodiments of the present application further provide an energy storage system, which includes the power conversion device 2 and the energy storage device 1 provided by some embodiments of the third aspect. The power conversion device 2 is used to electrically connect the power generation device 3 and the energy storage device 1.

[0256] The energy storage system can include one or more energy storage devices 1 and a power conversion device 2 (Power Converter System, PCS) connected between the power generation device 3 and the energy storage device 1. The power generation device 3 is used 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, and the like. The specific type of the power generation device 3 is not limited in the present application.

[0257] In a fifth aspect, some examples of the present application further provide a power consumption device, which includes 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 used to store or provide electric energy.

[0258] In a sixth aspect, referring to FIG. 14, some embodiments of the present application further provide a charging network, which includes 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 used to provide electric energy for the charging pile 4.

[0259] The charging pile 4 is electrically connected with the energy storage device 1, and the energy storage device 1 is used 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 stored electric energy to the charging pile 4. The charging pile 4 has one or more connectors 5, which are used to connect with the electric equipment (such as a vehicle), so as to supply electric energy to the electric equipment.

[0260] The energy storage device 1 can be located inside the charging pile 4 (for example, a charging and storage integrated machine), or outside the charging pile 4.

[0261] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and the specification of the present application. Especially, as long as there is no structural conflict, each technical feature mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, 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 a main body portion and a tab portion connected to the main body portion, the tab portion extending from one side of the main body portion along a width direction of the current collector toward a direction away from the main body portion; an insulating layer provided on the tab portion and covering at least part of the tab portion, the insulating layer being located on the side of the tab portion close to the main body portion.

2. The battery cell of claim 1, wherein, The tab portion has at least two and is arranged at intervals along a length direction of the current collector. The insulating layer has at least two and is arranged correspondingly to the tab portion, and each of the insulating layers is arranged at intervals along the length direction of the current collector.

3. The battery cell according to claim 1 or 2, characterized in that, In the length direction of the current collector, the size of the insulating layer is less than or equal to the size of the tab portion.

4. The battery cell of any one of claims 1-3, wherein, In the same projection plane perpendicular to the thickness direction of the current collector, the orthographic projection of the insulating layer at least partially overlaps the orthographic projection of the tab portion, and the ratio of the size of the orthographic projection of the insulating layer to the size of the orthographic projection of the tab portion in the width direction of the current collector is less than or equal to 1:

3.

5. The battery cell of any one of claims 1-4, wherein, The yield strength of the insulating layer is greater than or equal to 25 MPa.

6. The battery cell of claim 5, wherein, The yield strength of the insulating layer is less than or equal to 100 MPa.

7. The battery cell of any one of claims 1-6, wherein, The thickness of the insulating layer is greater than or equal to 9 μm.

8. The battery cell of any one of claims 1-6, wherein, The thickness of the insulating layer ranges from 9 μm to 30 μm.

9. The battery cell of any one of claims 1-8, wherein, The main body portion comprises two end faces at opposite ends along the width direction of the current collector, and further comprises two side faces at opposite sides along the thickness direction of the current collector, and the tab portion is formed on the end faces; The pole piece further comprises an active material layer provided on the side faces, the active material layer covering at least part of the side faces; In the same projection plane perpendicular to the thickness direction of the current collector, the orthographic projection of the insulating layer at least partially overlaps the orthographic projection of the side face.

10. The battery cell of claim 9, wherein, The insulating layer comprises two sub-insulating layers corresponding to the two side faces, the sub-insulating layer comprising a first portion and a second portion connected to the first portion, the first portion covering at least part of the tab portion; In the same projection plane perpendicular to the thickness direction of the current collector, the orthographic projection of the second portion at least partially overlaps the orthographic projection of the side face.

11. The battery cell of claim 10, wherein, The active material layer covers part of the corresponding side face, and forms a blank area on the side face close to the tab portion, and the second portion covers at least part of the blank area.

12. The battery cell of claim 11, wherein, The sub-insulating layer further comprises a third portion connected to the second portion on the side opposite to the first portion, the second portion covering the blank area, and the third portion covering part of the active material layer.

13. The battery cell of claim 12, wherein, In the projection plane perpendicular to the thickness direction of the current collector, the size of the orthographic projection of the third portion ranges from 0.1 mm to 1 mm.

14. The battery cell of claim 10, wherein, The active material layer completely covers the corresponding side face, and the second portion covers part of the active material layer.

15. The battery cell of claim 14, wherein, In the projection plane perpendicular to the thickness direction of the current collector, the size of the orthographic projection of the second portion ranges from 0.1 mm to 1 mm.

16. The battery cell of claim 1, wherein, The tab portion has at least two and is arranged at intervals along a length direction of the current collector. The insulating layer has one, and the insulating layer covers at least one of the tab portions.

17. The battery cell of any one of claims 1-16, wherein, The insulation layer comprises a substrate layer and an adhesive layer disposed on the substrate layer, the adhesive layer is disposed on the side of the substrate layer facing the current collector, and the adhesive layer is connected to at least the tab portion.

18. The battery cell of any one of claims 1-17, wherein, The battery cell comprises an electrode assembly, and the electrode assembly comprises a tab, the tab comprising at least two tab portions stacked.

19. The battery cell of any one of claims 1-18, wherein, The battery cell is a cylindrical battery cell.

20. A battery device, characterized by The battery cell comprises the battery cell as claimed in any one of claims 1-19.

21. An energy storage device, comprising: The battery device comprises a plurality of battery cells as claimed in any one of claims 1-19, or a plurality of battery devices as claimed in claim 20. The battery cell is used for storing or providing electric energy.

22. An energy storage system characterized by, The energy storage device as claimed in claim 21 is used for electrically connecting a power generation device and the energy storage device.

23. An electrical device, comprising: The battery cell as claimed in any one of claims 1-19, the battery device as claimed in claim 20, the energy storage device as claimed in claim 21, or the energy storage system as claimed in claim 22 is used for storing or providing electric energy.

24. A charging network characterized by, The charging pile is electrically connected to the energy storage device as claimed in claim 21, or the energy storage system as claimed in claim 22. The energy storage device or the energy storage system is used for providing electric energy for the charging pile.

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