Battery cell, battery device, energy storage device, energy storage system and charging network

Abstract

The embodiment of the utility model discloses a battery monomer, a battery device, an energy storage device, an energy storage system and a charging network. The battery cell includes: a housing; the electrode terminal is arranged on the first wall of the shell; the electrode assembly set is contained in the containing cavity of the shell, the electrode assembly set comprises a main body part and a tab, the main body part comprises a first end face facing the first wall and a peripheral face intersecting with the first end face and surrounding the first end face, and the tab is located on the first end face; the current collecting component is used for electrically connecting the electrode terminal and the tab; a first insulating film covering the outer peripheral surface; the second insulating film comprises a body part and an extension part which are bent oppositely, the body part is arranged between the current collecting component and the first wall to isolate the current collecting component from the first wall, the extension part covers partial area of the peripheral surface, and the first insulating film wraps and fixes the extension part. According to the battery monomer, the battery device, the energy storage device, the energy storage system and the charging network provided by the embodiment of the invention, the insulating property and the reliability of the battery monomer can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of batteries, and more particularly, to a battery monomer, a battery device, an energy storage device, an energy storage system and a charging network. BACKGROUND

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

[0003] In the preparation process of the battery monomer, after the electrode assembly is prepared, it needs to be assembled into a metal shell. How to improve the insulation performance between the electrode assembly and the shell is a technical problem to be solved. UTILITY MODEL CONTENT

[0004] The embodiments of the present application provide a battery monomer, a battery device, an energy storage device, an energy storage system and a charging network, which can improve the insulation performance and reliability of the battery monomer.

[0005] In a first aspect, a battery monomer is provided, comprising: a shell having a receiving cavity; an electrode terminal disposed on a first wall of the shell; a set of electrode assemblies received in the receiving cavity, the set of electrode assemblies including at least one electrode assembly, the set of electrode assemblies including a main body portion and a tab, the main body portion including a first end face and an outer peripheral surface intersecting the first end face and surrounding the first end face, the tab being located at the first end face, the first end face facing the first wall; a current collecting member for electrically connecting the electrode terminal and the tab; a first insulating film covering the outer peripheral surface; and a second insulating film including an oppositely bent body portion and an extension portion, the body portion being disposed between the current collecting member and the first wall to isolate the current collecting member and the first wall, the extension portion covering a partial area of the outer peripheral surface, the first insulating film wrapping and fixing the extension portion.

[0006] Therefore, the battery monomer of the embodiments of the present application can effectively isolate the outer peripheral surface of the set of electrode assemblies from the shell by the first insulating film, and further isolate the first end face where the tab is located from the first wall by the second insulating film. The body portion of the second insulating film is located between the current collecting member and the first wall, which can reduce the influence of the second insulating film on the electrical connection between the current collecting member and the tab, i.e. can improve the insulation performance between the set of electrode assemblies and the shell, and can reduce the influence on the set of electrode assemblies and the current collecting member, thereby improving the reliability of the battery monomer.

[0007] In some embodiments, the second insulating film includes two opposite extending portions, and the two extending portions respectively cover at least part of two large faces of the outer circumferential surface, the large faces being the faces with the largest area of the outer circumferential surface. The second insulating film is provided with two opposite extending portions, so that the second insulating film has a relatively symmetrical structure, and the stability of the second insulating film can be improved. Further, each extending portion is used to cover a large face of the outer circumferential surface, so that the first insulating film can cover and fix the second insulating film, and the structural stability can be further improved, and the risk of insulation failure of the battery cell can be reduced.

[0008] In some embodiments, the battery cell further includes an insulating piece fixed between the first wall and the first end face, and the first insulating film is fixed to the insulating piece. The insulating piece can be used to isolate the first end face and the first wall. In addition, the first insulating film covering the outer circumferential surface is fixed to the insulating piece, so as to further improve the stability of various components inside the battery cell.

[0009] In some embodiments, the body portion is arranged between the current collecting member and the insulating piece, so that the second insulating film and the insulating piece are used together to isolate the electrode assembly set and the first wall, and to isolate the current collecting member and the first wall, so as to improve the insulation effect inside the battery cell.

[0010] In some embodiments, the insulating piece includes a first electrode lead-out hole, and the electrode terminal is connected to the current collecting member through the first electrode lead-out hole, so as to realize the electrical connection between the electrode terminal and the tab, and to output electric energy.

[0011] In some embodiments, the current collecting member includes an electrode terminal connecting portion, and the body portion includes a second electrode lead-out hole, and the electrode terminal and / or the electrode terminal connecting portion passes through the second electrode lead-out hole, so that the electrode terminal and the electrode terminal connecting portion are connected, so as to realize the electrical connection between the electrode terminal and the tab, and to output electric energy.

[0012] In some embodiments, the current collecting member includes a tab connecting portion used to be electrically connected to the tab, and the tab connecting portion is located between the body portion and the tab, so as to reduce the influence of the second insulating film on the electrical connection between the tab connecting portion and the tab.

[0013] In some embodiments, the battery cell further comprises a third insulating film, the third insulating film comprises a first region and a second region, the first region is bonded to the tab connecting part, the second region is pasted and covers a partial region of the outer circumferential surface, the second insulating film covers the third insulating film, and the length of the extension part covering the outer circumferential surface is greater than the length of the second region covering the outer circumferential surface along the thickness direction of the first wall. The third insulating film can isolate the tab connecting part and the first wall, thereby improving the insulation reliability between the tab connecting part and the first wall. The second insulating film further fixes the third insulating film, thereby improving the stability and reliability of the third insulating film.

[0014] In some embodiments, the melting point of the third insulating film is greater than the melting point of the second insulating film. In this way, during the use of the battery cell, when the temperature of the battery cell assembly increases, the third insulating film is less likely to be damaged compared to the second insulating film, thereby improving the insulation reliability between the tab and the first wall and reducing the risk of insulation failure.

[0015] In some embodiments, the battery cell further comprises a pressure relief mechanism arranged on the first wall, and the body part further comprises a pressure relief hole corresponding to the pressure relief mechanism. In this way, when the battery cell experiences thermal runaway, the pressure relief hole can reduce the obstruction of the second insulating film to the discharge of the battery cell, so that the pressure relief mechanism can be actuated in time to quickly discharge the discharge material, thereby improving the reliability of the battery cell.

[0016] In some embodiments, the battery cell further comprises a liquid injection structure arranged on the first wall, and the body part further comprises a liquid injection hole corresponding to the liquid injection structure. The liquid injection hole allows the electrolyte to smoothly infiltrate the electrode assembly, thereby improving the processing efficiency of the battery cell.

[0017] In some embodiments, the ratio of the length of the extension part covering the outer circumferential surface to the length of the outer circumferential surface along the thickness direction of the first wall is in the range of [0.08, 0.25]. Setting the ratio to be greater than or equal to 0.08 can increase the area of the outer circumferential surface covered by the extension part, and also increase the area of the extension part covered by the first insulating film, thereby improving the stability between the extension part and the first insulating film, and further improving the structural stability of the battery cell. Setting the ratio to be less than or equal to 0.25 can limit the area of the extension part, considering that the first insulating film can cover the outer circumferential surface, appropriately limiting the area of the extension part can reduce the overlapping area of the extension part and the first insulating film, reduce the space occupied by the extension part and the first insulating film on the surface of the outer circumferential surface, improve the space utilization of the battery cell, reduce the weight of the battery cell, and further improve the energy density of the battery cell.

[0018] In some embodiments, the electrode assembly is a stacked structure. The first insulating film can also be used to fix the set of electrode assemblies to improve the stability of the set of electrode assemblies. In particular, when the set of electrode assemblies includes a plurality of electrode assemblies, the outer circumferential surface of the set of electrode assemblies is surrounded by the first insulating film, which can increase the structural stability, reduce the misalignment and movement between the plurality of stacked electrode plates, and thus improve the performance of the set of electrode assemblies.

[0019] In some embodiments, the electrode assembly includes a first surface and a second surface arranged opposite along the thickness direction of the electrode assembly, and the electrode assembly further includes a plurality of fixing structures arranged at intervals, each of the plurality of fixing structures extending from an edge of the first surface to an edge of the second surface along the thickness direction of the electrode assembly, and the second insulating film covers the plurality of fixing structures. For a stacked electrode assembly, the plurality of electrode plates of the electrode assembly can be fixed by arranging the plurality of fixing structures to improve the stability of the electrode assembly. Further, the first insulating film and the second insulating film of the embodiments of the present application are arranged at least on the outer circumferential surface of the main body portion of the set of electrode assemblies, i.e., outside the plurality of fixing structures on the outer circumferential surface, which can reduce the movement and misalignment between the plurality of electrode assemblies to further improve the stability of the set of electrode assemblies.

[0020] In some embodiments, the first insulating film includes at least one insulating sheet, and the first insulating film is folded and pasted to the outer circumferential surface. Compared with the method of sleeving the set of electrode assemblies with a heat-shrinkable film or the like, the first insulating film of the embodiments of the present application adopts a sheet structure, and at least one insulating sheet can be wrapped and pasted to the outer circumferential surface by folding, which is simple in processing method, can improve the processing efficiency, and can make the first insulating film and the main body portion of the set of electrode assemblies fit more closely, thereby improving the space utilization of the battery cell.

[0021] In some embodiments, the first insulating film includes two insulating sheets, the two insulating sheets cover two large surfaces of the outer circumferential surface and overlap and are bonded at two side surfaces of the outer circumferential surface to cover the outer circumferential surface, and the area of the side surface of the outer circumferential surface is smaller than the area of the large surface of the outer circumferential surface. The two large surfaces of the outer circumferential surface are provided with relatively complete insulating sheets, and the two side surfaces of the outer circumferential surface are provided with overlapping regions of the two insulating sheets, which is simple in processing operation, facilitates improving the processing efficiency, and also improves the structural stability.

[0022] In some embodiments, the set of electrode assemblies includes a first electrode assembly and a second electrode assembly, and the insulating sheet pasted to the side surface of the outer circumferential surface of the first electrode assembly is pasted to the side surface of the outer circumferential surface of the second electrode assembly to improve the structural stability and reduce the risk of insulation failure of the first insulating film.

[0023] In some embodiments, the body part further comprises a second end face opposite to the first end face, the outer circumferential surface connects the first end face and the second end face, and the first insulating film covers at least a partial area of the second end face to isolate the second end face from the shell.

[0024] In some embodiments, the first insulating film is attached to and covers an edge area of the second end face; and the battery cell further comprises a partition piece attached to and covering an area of the second end face not covered by the first insulating film, and the partition piece covers the first insulating film. By directly attaching the first insulating film to the outer circumferential surface of the body part and the edge area of the second end face, the electrode assembly set can be effectively isolated from the shell, and the hot melting method is not required for fixation, thereby reducing the processing steps, facilitating the processing of the battery cell, and improving the processing efficiency of the battery cell. In addition, the first insulating film covers a partial area of the second end face of the body part, rather than the entire area, thereby reducing the weight. Meanwhile, the partition piece is attached to and covers the area of the second end face not covered by the first insulating film, and covers the first insulating film attached to the edge of the second end face. The partition piece can be used to isolate the second end face of the electrode assembly set from the shell, and the partition piece is fixed by attachment, which facilitates the processing and improves the processing efficiency of the battery cell.

[0025] In some embodiments, the shell comprises a housing having an opening, and a cover plate for covering the opening to form the accommodating cavity, and the cover plate comprises the first wall to facilitate the processing and assembly.

[0026] In a second aspect, a battery device is provided, comprising a plurality of battery cells according to the first aspect or any one of the embodiments of the first aspect.

[0027] In a third aspect, an energy storage device is provided, comprising a plurality of battery cells according to the first aspect or any one of the embodiments of the first aspect, or a plurality of battery devices according to the second aspect, wherein the battery cells or the battery devices are used for storing or providing electric energy.

[0028] In a fourth aspect, an energy storage system is provided, comprising a power conversion device and an energy storage device according to the third aspect, wherein the power conversion device is used for electrically connecting a power generation device and the energy storage device.

[0029] In a fifth aspect, a charging network is provided, comprising a charging pile and an energy storage device according to the third aspect or an energy storage system according to the fourth aspect, wherein the energy storage device is used for providing electric energy for the charging pile. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 Structure schematic diagram of a battery cell according to an embodiment of the present application;

[0031] Figure 2An exploded view of a partial structure of a battery cell according to an embodiment of the present application;

[0032] Figure 3 A structure view of a set of electrode assemblies according to an embodiment of the present application;

[0033] Figure 4 A structure view of an internal structure of a battery cell according to an embodiment of the present application;

[0034] Figure 5 A cross-sectional view of a battery cell according to an embodiment of the present application;

[0035] Figure 6 Another partial cross-sectional view of a battery cell according to an embodiment of the present application;

[0036] Figure 7 A structure view of a second insulating film according to an embodiment of the present application;

[0037] Figure 8 A structure view of a current collecting member, a second insulating film, and an insulating member in a battery cell according to an embodiment of the present application;

[0038] Figure 9 Another partial cross-sectional view of a battery cell according to another embodiment of the present application;

[0039] Figure 10 A cross-sectional view of an electrode assembly according to an embodiment of the present application;

[0040] Figure 11 A cross-sectional view of an electrode assembly according to another embodiment of the present application;

[0041] Figure 12 A front view of an electrode assembly according to an embodiment of the present application;

[0042] Figure 13 A bottom view of an electrode assembly according to an embodiment of the present application;

[0043] Figure 14 A top structure view of a set of electrode assemblies wrapped with a first insulating film according to an embodiment of the present application;

[0044] Figure 15 A top structure view of a set of electrode assemblies wrapped with a first insulating film according to another embodiment of the present application;

[0045] Figure 16 A top structure view of a set of electrode assemblies wrapped with a first insulating film according to still another embodiment of the present application;

[0046] Figure 17A plan view of a set of electrode assemblies with a first insulating film wrapped therearound, according to another embodiment of the present application;

[0047] Figure 18 A cross-sectional view of a battery cell, according to another embodiment of the present application;

[0048] Figure 19 A partial cross-sectional view of a battery cell, according to another embodiment of the present application;

[0049] Figure 20 A view of a second end surface of a main body portion to which a first insulating film is attached, according to another embodiment of the present application;

[0050] Figure 21 A view of an internal structure of a battery cell, according to another embodiment of the present application;

[0051] Figure 22 A plan view of a separator, according to another embodiment of the present application;

[0052] Figure 23 A bottom view of an electrode assembly to which a separator and a first insulating film are attached, according to another embodiment of the present application.

[0053] In the drawings, the drawings are not drawn to scale. DETAILED DESCRIPTION

[0054] The technical solutions in the embodiments of the present application will be described below with reference to the drawings.

[0055] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly below with reference to the drawings. Obviously, the described embodiments are only some of the embodiments of the present application, but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0056] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used in the specification of the present application are only for the purpose of describing the 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. The terms "first", "second" and the like in the specification and claims of the present application and the above description of drawings are used to distinguish different objects, and are not intended to describe a particular order or primary and secondary relationship.

[0057] Reference to an “embodiment” in this application means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. It is expressly understood that that the embodiments described in this application can be combined with each other in their various permutations and combinations.

[0058] In the description of the application, it should be noted that, unless otherwise explicitly specified and limited, the terms “mounting”, “connection”, “connecting”, “attachment” should be understood broadly, for example, can be fixedly connected, or detachably connected, or integrally connected; can be directly connected, or indirectly connected through an intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0059] The term “and / or” in this application is only to describe the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. In addition, the character “ / ” in this application generally represents that the front and rear associated objects have an “or” relationship.

[0060] In the embodiments of the application, the same reference signs represent the same parts, and for the sake of brevity, the detailed description of the same parts is omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device, are only exemplary and should not constitute any limitation on the application.

[0061] “Multiple” appearing in this application means more than two (including two), and similarly, “multiple groups” means more than two groups (including two groups), and “multiple pieces” means more than two pieces (including two pieces).

[0062] In the embodiments of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be activated by charging after discharging.

[0063] The battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead-acid battery, etc. The embodiments of the application are not limited in this regard.

[0064] A battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator disposed between the negative electrode and the positive electrode. During charging and discharging of the battery cell, active ions (e.g., lithium ions) are intercalated and deintercalated between the positive electrode and the negative electrode. The separator, which is disposed between the positive electrode and the negative electrode, can function to prevent short circuiting of the positive and negative electrodes while allowing the active ions to pass through.

[0065] In some embodiments, the positive electrode can be a positive electrode tab, which can include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0066] As an example, the positive electrode current collector has two opposing surfaces in the thickness direction of itself, and the positive electrode active material is disposed on either one or both of the two opposing surfaces of the positive electrode current collector.

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

[0068] As an example, the positive electrode active material can include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other conventional materials that can be used as battery positive electrode active materials can also be used.

[0069] In some embodiments, the negative electrode can be a negative electrode tab, which can include a negative electrode current collector.

[0070] As an example, the negative electrode current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, a pure metal, an alloy, a surface-treated metal, including but not limited to stainless steel, copper, aluminum, nickel, nickel, titanium, or silver, etc. can be used. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0071] As an example, the negative electrode tab can include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0072] As an example, the negative current collector has two surfaces opposite in the thickness direction thereof, and the negative active material is disposed on either one or both of the two opposite surfaces of the negative current collector.

[0073] As an example, the negative active material can include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based material, tin-based material, lithium titanate, and the like.

[0074] In some embodiments, the negative electrode can employ a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. When the foamed metal is used as the negative electrode tab, the surface of the foamed metal can not be provided with the negative active material, or of course can be provided with the negative active material.

[0075] As an example, the negative active material can be filled or / and deposited in the negative current collector.

[0076] In some embodiments, the material of the positive current collector can be aluminum, and the material of the negative current collector can be copper.

[0077] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0078] In some embodiments, the separator is a separator film. The type of the separator film is not particularly limited in the present application, and any porous structure separator film with good chemical stability and mechanical stability can be selected.

[0079] In some embodiments, the separator is a solid-state electrolyte. The solid-state electrolyte is disposed between the positive electrode and the negative electrode, and simultaneously functions as ion transmission and separation of the positive electrode and the negative electrode.

[0080] In some embodiments, the battery cell further includes an electrolyte, which functions as ion conduction between the positive electrode and the negative electrode. The type of the electrolyte is not particularly limited in the present application, and can be selected according to the needs. The electrolyte can be liquid, gel or solid.

[0081] The electrode assembly can be a roll structure, a stack structure, or a hybrid structure of roll and stack.

[0082] In some embodiments, the electrode assembly is a roll structure. The positive electrode tab and the negative electrode tab are rolled into a roll structure.

[0083] In some embodiments, the electrode assembly is a stack structure.

[0084] As an example, a plurality of positive electrode tabs and a plurality of negative electrode tabs can be respectively provided, and the plurality of positive electrode tabs and the plurality of negative electrode tabs are alternately and stacked.

[0085] As an example, the positive electrode tab can be provided in plurality, and the negative electrode tab is folded to form a plurality of folded segments which are stacked.

[0086] As an example, the positive electrode tab and the negative electrode tab are each folded to form a plurality of folded segments which are stacked.

[0087] As an example, the separator can be provided in plurality, and each of the separators is provided between any adjacent positive electrode tab or negative electrode tab.

[0088] As an example, the separator can be provided in plurality, and each of the separators is provided between any adjacent positive electrode tab or negative electrode tab.

[0089] In some embodiments, the electrode assembly can have a cylindrical shape, a flat shape, or a polygonal shape.

[0090] In some embodiments, the electrode assembly is provided with a tab, and the tab can guide current out of the electrode assembly. The tab includes a positive tab and a negative tab.

[0091] In the process of preparing a battery cell, after the electrode assembly is prepared, it needs to be loaded into a metal shell to complete the assembly. In order to achieve insulation between the electrode assembly and the shell, an insulating film can be provided on the outer surface of the electrode assembly. However, since the tab of the electrode assembly needs to be electrically connected to the current collecting member to output electrical energy, the insulating film is usually wrapped around the outer surface of the electrode assembly where the tab is not provided, and the end surface where the tab is located is not wrapped with the insulating film. However, there is a risk of insulation failure between the end surface without the insulating film and the shell, and between the tab and the shell, which affects the performance and service life of the battery cell.

[0092] Therefore, the battery cell, the battery device, the energy storage device, the energy storage system and the charging network provided in the embodiments of the present application can solve the above technical problems. The battery cell provided in the embodiments of the present application comprises a shell, an electrode terminal, an electrode assembly set, a current collecting member, a first insulating film and a second insulating film. The electrode terminal is arranged on a first wall of the shell. The electrode assembly set is accommodated in an accommodation cavity of the shell, and the electrode assembly set comprises at least one electrode assembly. The electrode assembly set comprises a main body part and a tab. The main body part comprises a first end face and an outer circumferential face. The tab is arranged on the first end face. The outer circumferential face intersects with the first end face and surrounds the first end face. The first end face faces the first wall. The current collecting member is used to electrically connect the tab and the electrode terminal. The first insulating film covers the outer circumferential face. The second insulating film comprises a body part and an extension part. The body part is arranged between the current collecting member and the first wall to isolate the current collecting member and the first wall. The extension part covers a partial area of the outer circumferential face. The first insulating film wraps and fixes the extension part. The first insulating film can effectively isolate the outer circumferential face of the electrode assembly set and the shell. The second insulating film can further isolate the first end face where the tab is located and the first wall. The body part of the second insulating film is arranged between the current collecting member and the first wall, which can reduce the influence of the second insulating film on the electrical connection between the current collecting member and the tab, that is, can improve the insulation performance between the electrode assembly set and the shell, and can reduce the influence on the electrode assembly set and the current collecting member, thereby improving the reliability of the battery cell. In addition, the fixation between the first insulating film and the main body part of the electrode assembly set can also realize the fixation of the second insulating film, which is convenient for processing and can improve the structural stability.

[0093] Figure 1 A structural schematic diagram of a battery cell 20 provided in the embodiments of the present application is shown; Figure 2 An exploded schematic diagram of a partial structure of the battery cell 20 provided in the embodiments of the present application is shown; Figure 3 A structural schematic diagram of an electrode assembly set 22 of the battery cell 20 provided in the embodiments of the present application is shown. As shown in the figure, Figures 1 to 3 The battery cell 20 provided in the embodiments of the present application comprises a shell 21, an electrode terminal 214 and an electrode assembly set 22.

[0094] Specifically, the shell 21 has an accommodation cavity. The electrode terminal 214 is arranged on a first wall 201 of the shell 21. The electrode assembly set 22 is accommodated in the accommodation cavity, and the electrode assembly set 22 comprises a main body part 221 and a tab 222. The main body part 221 comprises a first end face 2211 and an outer circumferential face 2213. The outer circumferential face 2213 intersects with the first end face 2211 and surrounds the first end face 2211. The tab 222 is located on the first end face 2211. The first end face 2211 faces the first wall 201.

[0095] In the embodiments of the present application, the battery monomer 20 can include a shell 21, and an accommodating cavity inside the shell 21 is used to accommodate a set of electrode assemblies 22. The shell 21 can be a hollow structure of a polyhedron, which can be used to accommodate the set of electrode assemblies 22.

[0096] In some embodiments, the shell 21 can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film, etc. In some embodiments, the shell 21 can be a sealed structure, or can be a non-sealed structure.

[0097] For ease of illustration, the embodiments of the present application take a cuboid battery monomer 20 as an example, i.e., the shell 21 is approximately a cuboid; and take the cuboid battery monomer 20 as an example to define three reference directions: the length direction of the battery monomer 20 is the direction X, the thickness direction of the battery monomer 20 is the direction Y, and the height direction of the battery monomer 20 is the direction Z, wherein the thickness direction Y, the height direction Z, and the length direction X of the battery monomer 20 are perpendicular to each other, and the thickness direction Y of the battery monomer 20 is smaller than the length direction X.

[0098] It should be understood that the set of electrode assemblies 22 in the embodiments of the present application can include at least one electrode assembly 220, each electrode assembly 220 is a component that generates an electrochemical reaction in the battery monomer 20, and the specific number of electrode assemblies 220 included in the set of electrode assemblies 22 in the battery monomer 20 can be set to one or more according to actual use requirements. The shape of the set of electrode assemblies 22 in the embodiments of the present application can be set according to actual application, and the shapes of all electrode assemblies 220 included in the set of electrode assemblies 22 are usually the same, for example, the electrode assembly 220 can be a cylinder, a cuboid, etc. In addition, the shape of the outside of the battery monomer 20 can be the same as or different from the shape of the set of electrode assemblies 22. For example, if the set of electrode assemblies 22 is a cylindrical structure, the shell 21 of the battery monomer 20 can also be a cylindrical structure, or can also be a cuboid structure; if the set of electrode assemblies 22 is a cuboid structure, the shell 21 can also be a cuboid structure, but the embodiments of the present application are not limited thereto. For ease of illustration, as shown in the drawings, the embodiments of the present application mainly take a cuboid set of electrode assemblies 22 as an example, and each electrode assembly 220 is also a cuboid. Figures 1 to 3

[0099] ​The electrode assembly set 22 of the embodiment of the present applicationapplicationinclude the tab 222 and the main body part 221. Specifically, the electrode assembly set 22applicationinclude at least two tabs 222, whichapplicationinclude at least one positive tab 222a and at least one negative tab 222b. Each positive tab 222aapplicationbe formed by layering the portion of the positive electrode tab of one or more electrode assemblies 220 on which the positive active material layer is not coated, while the portion of the corresponding positive electrode tab on which the positive active material layer is coatedapplicationbe wound or layered to form the main body part 221 of the electrode assembly set 22. Each negative tab 222bapplicationbe formed by layering the portion of the negative electrode tab of one or more electrode assemblies 220 on which the negative active material layer is not coated, while the portion of the corresponding negative electrode tab on which the negative active material layer is coatedapplicationbe wound or layered to form the main body part 221 of the electrode assembly set 22. That is, the main body part 221 of the electrode assembly set 22 includes the portion of the positive electrode tab of all the electrode assemblies 220 on which the positive active material layer is coated and the portion of the negative electrode tab on which the negative active material layer is coated.

[0100] The plurality of tabs 222 of the electrode assembly set 22 of the embodiment of the present applicationapplicationbe located at the same end surface of the electrode assembly set 22. For example, as shown in FIG. 1, the embodiment of the present applicationapplicationmainly take the case where all the tabs 222 included in the electrode assembly set 22 are arranged at the first end surface 2211 of the main body part 221 of the electrode assembly set 22 as an example, but the embodiment of the present application is not limited thereto. Figures 1 to 3

[0101] The main body part 221 of the embodiment of the present applicationapplicationfurther include the outer circumferential surface 2213 which intersects the first end surface 2211 and surrounds the first end surface 2211. For example, as shown in FIG. 1, taking the approximately cuboid main body part 221 as an example, the outer circumferential surface 2213 which connects and surrounds the first end surface 2211applicationinclude four surfaces in the case where the first end surface 2211 is provided with the tabs 222. Figures 1 to 3

[0102] The housing 21 of the battery cell 20 of the embodiment of the present applicationapplicationfurther be provided with the electrode terminal 214, whichapplicationbe electrically connected to the electrode assembly set 22 to output the electric energy of the battery cell 20. As shown in FIG. 1, the electrode terminal 214applicationbe arranged at the second end surface 2212 of the main body part 221 of the electrode assembly set 22. Figures 1 to 3 ​​As shown, the battery cell 20 may include at least two electrode terminals 214, including at least one positive electrode terminal 214a and at least one negative electrode terminal 214b. Each electrode terminal 214 is used for electrical connection with a corresponding tab 222. For example, each electrode terminal 214 can be electrically connected to the corresponding tab 222 via a current collector 27. For example, the positive tab 222a of the electrode assembly 22 can be connected to the positive electrode terminal 214a via one current collector 27, and the negative tab 222b of the electrode assembly 22 can be connected to the negative electrode terminal 214b via another current collector 27.

[0103] At least two electrode terminals 214 of the battery cell 20 can be disposed on the same wall or different walls of the battery cell 20. For example, the positions of the electrode terminals 214 can be set according to the positions of the tabs 222 of the electrode assembly 22. For example, as Figures 1 to 3 As shown, the embodiment of this application mainly takes the battery cell 20 as having two electrode terminals 214, and the two electrode terminals 214 being disposed on the first wall 201 of the battery cell 20. The first wall 201 is any wall of the outer casing 21, and the first end face 2211 faces the first wall 201 so that the tab 222 can be electrically connected to the electrode terminal 214.

[0104] Figure 4 A schematic diagram of the internal structure of the battery cell 20 according to an embodiment of this application is shown. For example, the... Figure 4 The battery cell 20 shown can be Figure 1 and Figure 2 One possible implementation of the battery cell 20 shown. Figure 5 A cross-sectional schematic diagram of the battery cell 20 according to an embodiment of this application is shown. For example, the... Figure 5 The battery cell 20 shown can be Figure 4 The cross-sectional view of the battery cell 20 shown is as follows: Figure 5 It can also be Figure 1 and Figure 2 One possible implementation of the battery cell 20 shown is as follows: Figure 5 The cross-section shown is perpendicular to the length direction X of the battery cell 20, i.e. Figure 5 For example, the edge of the battery cell 20 Figure 4 The cross-sectional diagram along the A-A' direction is shown. Figure 6 Another partial cross-sectional schematic diagram of the battery cell 20 according to an embodiment of this application is shown, for example, Figure 6 The battery cell 20 shown can be Figure 4 The cross-sectional view of the battery cell 20 shown is shown, and Figure 6 The cross-section shown is perpendicular to the length direction X of the battery cell 20, and Figure 6The cross section shown passes through the electrode terminal 214.

[0105] As Figures 1 to 6 shown, the battery cell 20 of the embodiment of the application further comprises a current collecting member 27, a first insulating film 23 and a second insulating film 26. Specifically, the current collecting member 27 is used to electrically connect the electrode terminal 214 and the tab 222; the first insulating film 23 covers the outer peripheral surface 2213; the second insulating film 26 comprises a relatively bent body part 261 and an extension part 262, the body part 261 is arranged between the current collecting member 27 and the first wall 201 to isolate the current collecting member 27 and the first wall 201, the extension part 262 covers part of the outer peripheral surface 2213, and the first insulating film 23 wraps and fixes the extension part 262.

[0106] It should be understood that the current collecting member 27 of the embodiment of the application is used to electrically connect the electrode terminal 214 and the tab 222. For example, the current collecting member 27 used to electrically connect the positive tab 222a and the positive electrode terminal 214a can be located between the positive tab 222a and the positive electrode terminal 214a; the current collecting member 27 used to electrically connect the negative tab 222b and the negative electrode terminal 214b can be located between the negative tab 222b and the negative electrode terminal 214b, so as to facilitate the processing and assembly of the battery cell 20.

[0107] The first insulating film 23 of the embodiment of the application covers the outer peripheral surface 2213, which can effectively isolate the outer peripheral surface 2213 of the electrode assembly set 22 and the shell 21.

[0108] The second insulating film 26 of the embodiment of the application comprises a relatively bent body part 261 and an extension part 262. The body part 261 is arranged between the current collecting member 27 and the first wall 201, which can isolate the current collecting member 27 and the first wall 201, and can also be used to isolate the first end surface 2211 where the tab 222 is located and the first wall 201, which can reduce the influence of the second insulating film 26 on the electrical connection between the current collecting member 27 and the tab 222, i.e. can improve the insulation performance between the electrode assembly set 22 and the shell 21, and can also reduce the influence on the electrode assembly set 22 and the current collecting member 27, thereby improving the reliability of the battery cell 20.

[0109] The extension part 262 of the second insulating film 26 of the embodiment of the application covers part of the outer peripheral surface 2213, and the first insulating film 23 wraps and fixes the extension part 262. Through the fixing between the first insulating film 23 and the electrode assembly set 22, the fixing of the second insulating film 26 is also achieved synchronously, which not only facilitates processing, but also can improve the structural stability.

[0110] In the embodiments of the present application, the shell 21 comprises a housing 211 having an opening 2111, and a cover plate 212 configured to cover the opening 2111 to form a containing cavity. Specifically, the housing 211 is a hollow structure having the opening 2111, and the electrode assembly set 22 wrapped with the first insulation film 23 is contained in the housing 211 through the opening 2111; the cover plate 212 is configured to cover the opening 2111 of the housing 211 to isolate the external environment.

[0111] In some embodiments, the housing 211 can be a hollow structure having the opening 2111 formed at least at one end, and the cover plate 212 can be shaped to match the shape of the housing 211, and the cover plate 212 is configured to cover the opening 2111 of the housing 211, so that the shell 21 isolates the internal environment of the battery cell 20 from the external environment. If the housing 211 is a hollow structure having the opening 2111 formed at one end, the cover plate 212 can be provided as one; or if the housing 211 is a hollow structure having the opening 2111 formed at opposite ends, the cover plate 212 can be provided as two, and the two cover plates 212 are respectively configured to cover the openings 2111 at the two ends of the housing 211, and the embodiments of the present application are not limited thereto.

[0112] The material of the housing 211 of the embodiments of the present application can be various, such as copper, iron, aluminum, steel, aluminum alloy, etc. The material of the cover plate 212 can also be various, such as copper, iron, aluminum, steel, aluminum alloy, etc., and the material of the cover plate 212 can be the same as or different from the material of the housing 211.

[0113] The shape of the housing 211 and the cover plate 212 of the embodiments of the present application match each other, for example, the housing 211 can be an approximate cuboid structure, and the cover plate 212 can be an approximate rectangular plate structure matching the housing 211. The cover plate 212 can be any wall of the shell 21, for example, the cover plate 212 can be the largest wall among the multiple walls included in the shell 21, or the smallest wall, or can also be other walls, and the embodiments of the present application are not limited thereto. Alternatively, the cover plate 212 can also be other structures, for example, the cover plate 212 can also be a groove structure having an opening, so as to cover the opening 2111 of the housing 211, and the embodiments of the present application are not limited thereto.

[0114] For the convenience of description, the housing 211 is mainly taken as an example of a hollow structure having an opening at one end; correspondingly, one cover plate 212 is provided to cover the opening 2111 of the housing 211, for example, the sealing connection between the housing 211 and the cover plate 212 can be achieved by welding, so as to form a closed cavity for placing the electrode assembly set 22, and improve the sealing reliability.

[0115] It should be understood that the relative positional relationship between the various end faces of the main body 221 and the outer shell 21 in this embodiment can be flexibly set according to actual application. For example, the first end face 2211 with the tab 222 can face any wall of the outer shell 21.

[0116] In some embodiments, such as Figures 1 to 6 As shown, this embodiment mainly takes the cover plate 212 including the first wall 201 as an example, that is, the first end face 2211 is disposed facing the cover plate 212, and the electrode terminal 214 is located on the cover plate 212, so as to facilitate processing and installation. For example, during installation, the electrode assembly 22 wrapped with the first insulating film 23 can be inserted into the housing 211 through the opening 2111 of the housing 211, and the first end face 2211 of the electrode assembly 22 with the tab 222 is disposed facing the opening 2111, and then the cover plate 212 is closed to cover the opening 2111.

[0117] In some embodiments, such as Figures 1 to 6 As shown, the second insulating film 26 includes two opposing extensions 262, each covering at least a portion of the two large surfaces 2214 of the outer peripheral surface 2213, where the large surfaces 2214 are the surfaces with the largest area. By configuring the second insulating film 26 with two opposing extensions 262, a relatively symmetrical structure is achieved, which improves the stability of the second insulating film 26. Furthermore, each extension 262 covers the large surface 2214 of the outer peripheral surface 2213, facilitating the first insulating film 23 to cover and fix the second insulating film 26, further enhancing structural stability and reducing the risk of insulation failure in the battery cell 20.

[0118] Figure 7 A schematic diagram of the structure of the second insulating film 26 according to an embodiment of this application is shown, for example, Figure 7 This can be a top view of the second insulating film 26 in the unfolded state according to an embodiment of this application. Figure 7 As shown, the second insulating film 26 can be a sheet-like structure with two relatively parallel folds 263. By bending the second insulating film 26 along the two folds 263, the main body 261 and two oppositely arranged extensions 262 can be obtained. The main body 261 is disposed between the first wall 201 and the current collecting member 27. By bending the second insulating film 26 through the two pre-set folds 263, the two extensions 262 can cover the two large surfaces 2214 of the outer peripheral surface 2213. The operation is simple and easy to implement.

[0119] In the embodiment of the present application, the battery cell 20 further comprises an insulating member 25 fixed between the first wall 201 and the first end surface 2211, and the first insulating film 23 is fixed to the insulating member 25. The insulating member 25 can be used to isolate the first end surface 2211 from the first wall 201, and the first insulating film 23 covering the outer circumferential surface 2213 is fixed to the insulating member 25 to further improve the stability of the various components inside the battery cell 20.

[0120] In some embodiments, the body part 261 is arranged between the current collecting member 27 and the insulating member 25, so that the second insulating film 26 and the insulating member 25 are used together to isolate the electrode assembly set 22 from the first wall 201 and to isolate the current collecting member 27 from the first wall 201, thereby improving the insulation effect inside the battery cell 20.

[0121] In some embodiments, as shown in Figures 4 to 7 , the insulating member 25 comprises a first electrode lead-out hole 251, and the electrode terminal 214 is connected to the current collecting member 27 through the first electrode lead-out hole 251 to realize the electrical connection between the electrode terminal 214 and the tab 222, thereby outputting electric energy.

[0122] In some embodiments, as shown in Figures 4 to 7 , the first wall 201 comprises a third electrode lead-out hole 2011, and the electrode terminal 214 is connected to the current collecting member 27 through the third electrode lead-out hole 2011, for example, the electrode terminal 214 can sequentially pass through the third electrode lead-out hole 2011 and the first electrode lead-out hole 251 to be connected to the current collecting member 27 to realize the electrical connection between the electrode terminal 214 and the tab 222, thereby outputting electric energy.

[0123] In some embodiments, as shown in Figures 4 to 7 , the body part 261 comprises a second electrode lead-out hole 2611, and the electrode terminal 214 and / or the current collecting member 27 passes through the second electrode lead-out hole 2611 to be connected to the current collecting member 27, for example, the electrode terminal 214 can sequentially pass through the third electrode lead-out hole 2011, the first electrode lead-out hole 251 and the second electrode lead-out hole 2611 to be connected to the current collecting member 27; or the electrode terminal 214 can sequentially pass through the third electrode lead-out hole 2011 and the first electrode lead-out hole 251, and the current collecting member 27 passes through the second electrode lead-out hole 2611 to be connected to the electrode terminal 214, to realize the electrical connection between the electrode terminal 214 and the tab 222, thereby outputting electric energy.

[0124] Figure 8 The structural schematic diagram of the current collecting member 27, the second insulating film 26 and the insulating member 25 in the battery cell 20 of the embodiment of the present application is shown, for example, Figure 8 , which can be as shown in Figures 4 to 6A bottom view of the battery cell 20 is shown in FIG. 2. The battery cell 20 includes the current collecting member 27, the second insulating film 26, and the insulating member 25.

[0125] In some embodiments, as shown in FIG. 2, the current collecting member 27 includes an electrode terminal connecting portion 271 for electrically connecting with the electrode terminal 214. Figures 4 to 8 For example, the electrode terminal 214 is connected with the electrode terminal connecting portion 271 through the second electrode lead-out hole 2611. For another example, the electrode terminal 214 is connected with the electrode terminal connecting portion 271 by sequentially passing through the third electrode lead-out hole 2011, the first electrode lead-out hole 251, and the second electrode lead-out hole 2611.

[0126] In some embodiments, as shown in FIG. 2, the electrode terminal 214 can sequentially pass through the third electrode lead-out hole 2011 and the first electrode lead-out hole 251, and the electrode terminal connecting portion 271 passes through the second electrode lead-out hole 2611. For example, the electrode terminal connecting portion 271 can protrude towards the electrode terminal 214 through the second electrode lead-out hole 2611, so that the electrode terminal 214 is connected with the electrode terminal connecting portion 271 of the current collecting member 27. Figures 4 to 8 In some embodiments, as shown in FIG. 2, the electrode terminal 214 can sequentially pass through the third electrode lead-out hole 2011 and the first electrode lead-out hole 251, and the electrode terminal connecting portion 271 passes through the second electrode lead-out hole 2611. For example, the electrode terminal connecting portion 271 can protrude towards the electrode terminal 214 through the second electrode lead-out hole 2611, so that the electrode terminal 214 is connected with the electrode terminal connecting portion 271 of the current collecting member 27.

[0127] In some embodiments, as shown in FIG. 2, the current collecting member 27 includes a tab connecting portion 272 for electrically connecting with the tab 222. The tab connecting portion 272 is located between the body portion 261 and the tab 222, i.e., the body portion 261 of the second insulating film 26 is located on the side of the tab connecting portion 272 of the current collecting member 27 away from the tab 222, so as to reduce the influence of the second insulating film 26 on the electrical connection between the tab connecting portion 272 and the tab 222.

[0128] Figures 4 to 8 In some embodiments, as shown in FIG. 2, the current collecting member 27 includes a tab connecting portion 272 for electrically connecting with the tab 222. The tab connecting portion 272 is located between the body portion 261 and the tab 222, i.e., the body portion 261 of the second insulating film 26 is located on the side of the tab connecting portion 272 of the current collecting member 27 away from the tab 222, so as to reduce the influence of the second insulating film 26 on the electrical connection between the tab connecting portion 272 and the tab 222.

[0129] ​In some embodiments, the battery cell 20 further comprises a pressure relief mechanism 213 disposed on the first wall 201, and the body portion 261 further comprises a pressure relief hole 2612 corresponding to the pressure relief mechanism 213. In this way, when the battery cell 20 experiences thermal runaway, the second insulating film 26 can be reduced to hinder the battery cell 20 from discharging the emissions outward, so that the pressure relief mechanism 213 can be actuated in time to quickly discharge the emissions, thereby improving the reliability of the battery cell 20.

[0130] It should be understood that the pressure relief mechanism 213 of the embodiments of the present application is used to actuate when the internal pressure or temperature of the battery cell 20 reaches a predetermined threshold, so as to release the internal pressure or temperature. When the internal pressure or temperature of the battery cell 20 reaches the predetermined threshold, the pressure relief mechanism 213 performs an action or a weak structure provided in the pressure relief mechanism 213 is broken, thereby forming an opening or a passage for the internal pressure or temperature to be released. The threshold value is designed differently according to different design requirements. The threshold value can depend on the material of one or more of the positive plate, the negative plate, the electrolyte, and the separator in the battery cell 20.

[0131] As an example, the pressure relief mechanism 213 can be integrally formed with the first wall 201 in which the pressure relief mechanism 213 is disposed; or the pressure relief mechanism 213 can be separately provided and connected with the first wall 201.

[0132] The "actuation" mentioned in the present application refers to the pressure relief mechanism 213 generating an action or being activated to a certain state, so that the internal pressure and temperature of the battery cell 20 can be released. The action generated by the pressure relief mechanism 213 can include but is not limited to: a component in the pressure relief mechanism 213 moving to form an exhaust passage, at least a part of the pressure relief mechanism 213 breaking, shattering, being torn or opening, etc. When the pressure relief mechanism 213 is actuated, the high-temperature and high-pressure substances inside the battery cell 20 will be discharged outward from the actuated part as emissions. In this way, the battery cell 20 can be pressure-released and temperature-released under controllable pressure or temperature, thereby avoiding potential more serious accidents.

[0133] The emissions from the battery cell 20 mentioned in the present application include but are not limited to: electrolyte, dissolved or split positive and negative plates, fragments of the separator, high-temperature and high-pressure gas generated by reaction, flame, etc.

[0134] It should be understood that the size and shape of the pressure relief hole 2612 can be set according to the size and shape of the corresponding pressure relief mechanism 213. For example, the shape of the pressure relief hole 2612 can be the same as or similar to the shape of the pressure relief mechanism 213 to facilitate processing. For another example, the area of the pressure relief mechanism 213 is usually less than or equal to the area of the pressure relief hole 2612, that is, the projection of the pressure relief mechanism 213 toward the body portion 261 is usually within the range of the pressure relief hole 2612, so that the pressure relief hole 2612 does not block the pressure relief mechanism 213, thereby reducing the blocking effect of the pressure relief hole 2612 on the exhaust when the battery cell 20 is in thermal runaway, thereby improving the reliability of the battery cell 20.

[0135] In some embodiments, the battery cell 20 further comprises a liquid injection structure 215 arranged on the first wall 201, and the body portion 261 further comprises a liquid injection hole 2613 arranged corresponding to the liquid injection structure 215. By arranging the liquid injection hole 2613, the electrolyte can smoothly infiltrate the electrode assembly set 22, thereby facilitating the processing efficiency of the battery cell 20.

[0136] It should be understood that the liquid injection structure 215 of the embodiments of the present application can include a liquid injection through hole arranged on the first wall 201 and a sealing structure for sealing the liquid injection through hole. By arranging the liquid injection through hole on the first wall 201 and the liquid injection hole 2613 of the body portion 261, the electrolyte is injected into the inside of the battery cell 20, and the liquid injection through hole of the first wall 201 is sealed by the sealing structure to reduce the risk of electrolyte leakage and improve the reliability and stability of the battery cell 20.

[0137] It should be understood that the size of the extension portion 262 of the embodiments of the present application can be set according to actual application. For example, as shown in FIG. 6, the extension portion 262 can be arranged on the first wall 201, and the extension portion 262 can be arranged on the second wall 202. Figures 4 to 8As shown, the ratio of the length D1 of the extension 262 covering the outer circumferential surface 2213 to the length D2 of the outer circumferential surface 2213 in the thickness direction of the first end surface 2211 is in the range of [0.08, 0.25]. For example, taking the thickness direction of the first end surface 2211 as the height direction Z of the battery cell 20, setting the ratio of the length D1 of the extension 262 covering the outer circumferential surface 2213 to the length D2 of the outer circumferential surface 2213 to be greater than or equal to 0.08 can increase the area of the outer circumferential surface 2213 covered by the extension 262, and also increase the area of the extension 262 covered by the first insulating film 23, thereby improving the stability between the extension 262 and the first insulating film 23, and further improving the structural stability of the battery cell 20. Setting the ratio of the length D1 of the extension 262 covering the outer circumferential surface 2213 to the length D2 of the outer circumferential surface 2213 to be less than or equal to 0.25 can limit the area of the extension 262, and considering that the first insulating film 23 can cover the outer circumferential surface 2213, appropriately limiting the area of the extension 262 can reduce the area of the extension 262 overlapping with the first insulating film 23, reduce the space occupied by the extension 262 and the first insulating film 23 on the surface of the outer circumferential surface 2213, improve the space utilization of the battery cell 20, reduce the weight of the battery cell, and further improve the energy density of the battery cell 20.

[0138] Figure 9 Another partial cross-sectional view of the battery cell 20 according to an embodiment of the present application is shown, for example, Figure 9 The battery cell 20 shown can be Figure 4 Another possible partial cross-sectional view of the battery cell 20 is shown, and Figure 9 The cross-section shown is perpendicular to the length direction X of the battery cell 20, and Figure 9 The cross-section shown passes through the electrode terminal 214.

[0139] In some embodiments, as Figure 9 As shown, the battery cell further includes a third insulating film 28, the third insulating film 28 includes a first region 281 and a second region 282, the first region 281 is bonded to the tab connecting portion 272, and the second region 282 is pasted and covers part of the outer circumferential surface 2213, and the second insulating film 26 covers the third insulating film 28. The third insulating film 28 provided can isolate the tab connecting portion 272 and the first wall 201, thereby improving the insulation reliability between the tab connecting portion 272 and the first wall 201.

[0140] In some embodiments, the first region 281 can also be used to paste and cover the surface of the tab 222 facing the first wall 201 and not covered by the current collecting member 27, for example, the first region 281 can cover the edge region of the tab 222 not covered by the current collecting member 27, to isolate the part of the tab 222 from the first wall 201, further improving the internal insulation reliability of the battery monomer 20.

[0141] In some embodiments, the first region 281 can also be used to paste and cover part of the first end surface 2211, for example, the first region 281 can cover the outer edge region of the first end surface 2211, to isolate the part of the first end surface 2211 from the first wall 201, further improving the internal insulation reliability of the battery monomer 20.

[0142] In some embodiments, the first region 281 of the third insulation film 28 is located between the first end surface 2211 and the body part 261 of the second insulation film 26, by bending the third insulation film 28, so that the second region 282 of the third insulation film 28 pastes and covers part of the outer peripheral surface 2213, which can improve the stability and reliability of the third insulation film 28, and further reduce the risk of insulation failure between the tab 222 and the first wall 201.

[0143] In some embodiments, the length of the extension part 262 covering the outer peripheral surface 2213 is greater than the length of the second region 282 covering the outer peripheral surface 2213 along the thickness direction of the first wall 201, so that the second insulation film 26 further fixes the third insulation film 28, to improve the stability and reliability of the third insulation film 28. As shown in the Figure 9 length of the extension part 262 covering the outer peripheral surface 2213 is greater than the length of the second region 282 covering the outer peripheral surface 2213 along the thickness direction of the first wall 201, then the end of the extension part 262 away from the first wall 201 exceeds the end of the second region 282 away from the first wall 201, so that the extension part 262 can cover the entire region of the second region 282, further fixing the second region 282.

[0144] In some embodiments, the melting point of the third insulation film 28 is greater than the melting point of the second insulation film 26, so that in the case of temperature rise of the battery monomer assembly 22 during use of the battery monomer 20, the third insulation film 28 is less likely to be damaged than the second insulation film 26, which can improve the insulation reliability between the tab 222 and the first wall 201, and reduce the risk of insulation failure.

[0145] It should be understood that the melting point of the embodiments of the present application refers to the temperature at which the material is damaged. For example, the melting point of the third insulation film 28 refers to the temperature at which the third insulation film 28 is damaged or melted.

[0146] It should be understood that the material of the third insulating film 28 can be set according to the actual application. For example, the material of the third insulating film 28 may include polyimide (PI) to make the third insulating film 28 resistant to high temperatures and easy to implement.

[0147] It should be understood that each electrode assembly 220 included in the electrode assembly set 22 of this application embodiment can be a wound electrode assembly or a stacked electrode assembly, to suit different application scenarios. Furthermore, the multiple electrode assemblies 220 included in the electrode assembly set 22 are generally of the same type; for example, they can all be wound electrode assemblies or stacked electrode assemblies.

[0148] The electrode assembly 220 of any embodiment of this application will now be described with reference to the accompanying drawings.

[0149] In some embodiments, the electrode assembly 220 of this application can be a wound electrode assembly. Specifically, the electrode assembly 220 may include a positive electrode and a negative electrode, which are wound together around a winding shaft to form the wound electrode assembly 220.

[0150] In some embodiments, the electrode assembly 220 of this application can be a stacked electrode assembly, and the specific structure of the stacked electrode assembly can be set according to the actual application. Figure 10 A cross-sectional schematic diagram of the electrode assembly 220 according to an embodiment of this application is shown, wherein... Figure 10 The cross-section shown is perpendicular to the height direction of the battery cell 20, and the Figure 10 The electrode assembly 220 shown can be as follows: Figures 1 to 3 One possible implementation of any one of the electrode components 220 in the electrode component set 220 shown. For example... Figure 10 As shown, the portion of the electrode assembly 220 corresponding to the main body 221 includes a plurality of first electrode sheets 223 and a plurality of second electrode sheets 224 with opposite polarities. The plurality of first electrode sheets 223 and the plurality of second electrode sheets 224 are alternately stacked along a first direction. For example, here the first direction is the thickness direction Y of the battery cell 20, thereby forming a stacked electrode assembly.

[0151] Figure 11 A cross-sectional schematic diagram of an electrode assembly 220 according to another embodiment of this application is shown, wherein... Figure 11 The cross-section shown is perpendicular to the height direction of the battery cell 20. Figure 11 The electrode assembly 220 shown can be as follows: Figures 1 to 3 Another possible implementation of any one of the electrode components 220 in the electrode component set 220 shown. For example...Figure 11 As shown, the portion of the electrode assembly 220 corresponding to the main body 221 includes a first electrode 223 with opposite polarities and a plurality of second electrodes 224. The first electrode 223 includes at least one bent section 2231 and a plurality of stacked sections 2232. The bent section 2231 is used to connect two adjacent stacked sections 2232. The plurality of stacked sections 2232 and the plurality of second electrodes 224 are stacked alternately along a first direction. For example, here the first direction is the thickness direction Y of the battery cell 20, thereby forming a stacked electrode assembly.

[0152] It should be understood that the first electrode 223 and the second electrode 224 in the embodiments of this application are electrodes with opposite polarities. For example, if the first electrode 223 is a positive electrode, then the second electrode 224 is a negative electrode; conversely, if the first electrode 223 is a negative electrode, then the second electrode 224 is a positive electrode. For example, as... Figure 10 and Figure 11 As shown, in this embodiment of the application, the first electrode 223 is used as the negative electrode and the second electrode 224 is used as the positive electrode to reduce the risk of metal deposition in the electrode assembly 220 and improve the electrical performance of the battery cell 20.

[0153] In this embodiment, the electrode assembly 220 further includes an isolator 225, which is disposed between the positive electrode and the negative electrode to isolate the positive electrode and the negative electrode.

[0154] For electrode assembly 22, including as follows Figure 10 and Figure 11 In the case of a stacked electrode assembly 220, the first insulating film 23 can also be used to fix the electrode assembly assembly 22 to improve the stability of the electrode assembly assembly 22. Especially when the electrode assembly assembly 22 includes multiple electrode assemblies 220, the first insulating film 23 surrounds the outer peripheral surface 2213 of the electrode assembly assembly 22. The first insulating film 23 can increase structural stability, reduce misalignment and movement between multiple stacked electrodes, and thus improve the performance of the electrode assembly assembly 22.

[0155] In some embodiments, for such Figure 10 and Figure 11 The stacked electrode assembly 220 may further include a fixing structure 2203 to fix the electrode assembly 220. Figure 12 and Figure 13 Schematic diagrams of the electrode assembly 220 at different angles according to embodiments of this application are shown. Figure 12 and Figure 13 The electrode assembly 220 shown can be Figure 10 or Figure 11 The electrode assembly 220 is shown. Among them, Figure 12A front view schematic diagram of the electrode assembly 220 according to an embodiment of this application is shown; Figure 13 A bottom view of the electrode assembly 220 according to an embodiment of this application is shown.

[0156] like Figure 12 and Figure 13 As shown, the electrode assembly 220 includes a first surface 2201 and a second surface 2202 disposed opposite to each other along the thickness direction of the electrode assembly 220. The electrode assembly 220 also includes a plurality of fixing structures 2203 disposed at intervals. Each of the plurality of fixing structures 2203 extends from the edge of the first surface 2201 along the thickness direction of the electrode assembly 220 to the edge of the second surface 2202. A second insulating film 26 covers the plurality of fixing structures 2203. For a stacked electrode assembly, by providing a plurality of fixing structures 2203, the plurality of electrodes of the electrode assembly 220 can be fixed to improve the stability of the electrode assembly 220. Further, in this embodiment, the first insulating film 23 and the second insulating film 26 are at least disposed on the outer peripheral surface 2213 of the main body portion 221 of the electrode assembly assembly 22, that is, disposed on the outside of the plurality of fixing structures 2203 of the main body portion 221, and cover at least a portion of the area of ​​at least one of the fixing structures 2203. This can reduce the movement and misalignment between the plurality of electrode assemblies 220, thereby further improving the stability of the electrode assembly assembly 22.

[0157] In some embodiments, different regions of the electrode assembly 220 may be provided with at least one fixing structure 2203. For example, such as Figure 12 and Figure 13 As shown, taking the end faces of the electrode assembly 220 used to connect the first surface 2201 and the second surface 2202 as an example. Considering that the fixing structure 2203 is made of insulating material, the end faces of the electrode assembly 220 with the tabs 222 may not have any fixing structure 2203 or may have only a few fixing structures 2203 to reduce the impact on the tabs 222. For example, Figure 12 and Figure 13 Taking the first end face 2211 with tabs 222 having only one fixing structure 2203 as an example, the body portion 261 of the second insulating film 26 for covering the first end face 2211 is at least provided on the outside of the fixing structure 2203, and covers the area of ​​the fixing structure 2203 located on the first end face 2211. For the end face of the electrode assembly 220 without tabs 222, a certain number of fixing structures 2203 can be provided according to the size of the end face, for example... Figure 12 and Figure 13 The example provided in this application has three fixed structures 2203 on each end face, but the embodiments of this application are not limited to this.

[0158] The first insulating film 23 of the embodiment of the present application arranged on a partial region of the outer surface of the main body portion 221 will be described below with reference to the accompanying drawings.

[0159] It should be understood that the first insulating film 23 of the embodiment of the present application can be arranged on the surface of the main body portion 221 in various ways. For example, the first insulating film 23 is attached to a partial region of the surface of the main body portion 221, for example, the first insulating film 23 is attached to and covers the outer peripheral surface 2213 of the main body portion 221 to effectively isolate the electrode assembly set 22 from the case 21, and the first insulating film 23 does not need to be fixed by heat shrinkage, reducing the processing steps, facilitating the processing of the battery monomer 20, and improving the processing efficiency of the battery monomer 20.

[0160] In some embodiments, the first insulating film 23 includes at least one insulating sheet 231, and the first insulating film 23 is folded and attached to the outer peripheral surface 2213. Compared with the way of sleeving the electrode assembly set 22 outside by a heat-shrinkable film or the like, the first insulating film 23 of the embodiment of the present application adopts a sheet structure, and at least one insulating sheet 231 can be wrapped and attached to the outer peripheral surface 2213 by folding, which is simple in processing and can improve the processing efficiency, and the first insulating film 23 and the main body portion 221 of the electrode assembly set 22 can be more closely attached, which can improve the space utilization of the battery monomer 20.

[0161] Figure 14 A top view structural schematic diagram of the electrode assembly set 22 wrapped with the first insulating film 23 of the embodiment of the present application is shown, for example, the Figure 14 may be a possible way for the first insulating film 23 of the embodiment of the present application to wrap the outer peripheral surface 2213 of the electrode assembly set 22.

[0162] In some embodiments, as Figure 14 shown, the first insulating film 23 can include one insulating sheet 231, and the starting end and the ending end of the insulating sheet 231 are stacked and fixed with each other at any one end surface of the outer peripheral surface 2213. For example, Figure 14 the starting end and the ending end of the insulating sheet 231 are stacked with each other at the side surface 2215 of the outer peripheral surface 2213, wherein the side surface 2215 of the outer peripheral surface 2213 is the surface with the smallest area included in the outer peripheral surface 2213. Alternatively, Figure 14 the starting end and the ending end of the insulating sheet 231 can also be stacked with each other at other end surfaces of the outer peripheral surface 2213, and the embodiment of the present application is not limited thereto.

[0163] In some embodiments, as Figure 14As shown, the overlapping positions of the starting end and the ending end of the insulation sheet 231 can be located at any region of the side surface 2215 of the outer peripheral surface 2213, and the size of the overlapping region can also be set according to actual application. For example, the overlapping region of the starting end and the ending end of the insulation sheet 231 can cover the side surface of any one or more electrode assembly sets 22 or electrode assemblies 220; or, as shown, the overlapping region of the starting end and the ending end of the insulation sheet 231 can cover the middle region of any two electrode assemblies 220 in the electrode assembly set 22, and the embodiments of the present application are not limited thereto. Figure 14

[0164] Figures 15 to 17 The top view structural schematic diagrams of the electrode assembly set 22 wrapped with the first insulation film 23 according to other embodiments of the present application are shown respectively, for example, the Figures 15 to 17 The other possible ways of wrapping the outer peripheral surface 2213 of the electrode assembly set 22 with the first insulation film 23 according to the embodiments of the present application are shown.

[0165] In some embodiments, the first insulation film 23 can also include a plurality of insulation sheets 231, which are connected to each other to surround the outer peripheral surface 2213. The setting of the plurality of insulation sheets 231 to collectively surround the outer peripheral surface 2213 can improve the processing flexibility of the battery monomer 20 to adapt to different application scenarios and different types of battery monomers 20.

[0166] It should be understood that, in the case where the first insulation film 23 includes a plurality of insulation sheets 231, the position of each insulation sheet 231 can be set according to actual application.

[0167] For example, as shown, the first insulation film 23 includes two insulation sheets 231, which respectively cover the two large surfaces 2214 of the outer peripheral surface 2213 and overlap and are bonded at the two side surfaces 2215 of the outer peripheral surface 2213 to cover the outer peripheral surface 2213, and the area of the side surface 2215 of the outer peripheral surface 2213 is smaller than that of the large surface 2214 of the outer peripheral surface 2213. The relatively complete insulation sheet 231 is arranged at the two large surfaces 2214 of the outer peripheral surface 2213, and the overlapping region of the two insulation sheets 231 is arranged at the two side surfaces 2215 of the outer peripheral surface 2213, which is simple in processing operation and facilitates improving processing efficiency and structural stability. Figures 15 to 17 It should be understood that the position and size of the overlapping region of the two insulation sheets 231 of the first insulation film 23 at the two side surfaces 2215 of the outer peripheral surface 2213 can be set according to actual application.

[0168]

[0169] ​​For example, as shown in Figures 15 to 17 The electrode assembly set 22 includes a first electrode assembly 2201 and a second electrode assembly 2202, and an insulating sheet 231 adhered to a side of the outer circumferential surface of the first electrode assembly 2201 is adhered to a side of the outer circumferential surface of the second electrode assembly 2202, so as to improve structural stability and reduce the risk of insulation failure of the first insulating film 23.

[0170] Specifically, as shown in Figures 15 to 17 The electrode assembly set 22 includes a first electrode assembly 2201 and a second electrode assembly 2202, wherein the first electrode assembly 2201 has one large face 2214 of the outer circumferential surface 2213, and the second electrode assembly 2202 has another large face 2214 of the outer circumferential surface 2213; each side face 2215 of the outer circumferential surface 2213 includes a side face of the first electrode assembly 2201 and a side face of the second electrode assembly 2202. Correspondingly, the first insulating film 23 includes two insulating sheets 231, for example, taking the two insulating sheets 231 as a first insulating sheet 2311 and a second insulating sheet 2312. The first insulating sheet 2311 is used to adhere to the one large face 2214 of the outer circumferential surface 2213 of the first electrode assembly 2201, and the second insulating sheet 2312 is used to adhere to the other large face 2214 of the outer circumferential surface 2213 of the second electrode assembly 2202.

[0171] Further, the insulating sheet 231 adhered to the side of the outer circumferential surface of the first electrode assembly 2201 is adhered to the side of the outer circumferential surface of the second electrode assembly 2202, that is, the first insulating sheet 2311 is also adhered to the region of the first electrode assembly 2201 and at least part of the region of the second electrode assembly 2202 of the side face 2215 of the outer circumferential surface 2213, that is, on each side face 2215 of the outer circumferential surface 2213, the first insulating sheet 2311 can extend from the region of the first electrode assembly 2201 to the region of the second electrode assembly 2202.

[0172] As shown in Figure 15 In the case where the first insulating sheet 2311 covers the region of the first electrode assembly 2201 and at least part of the region of the second electrode assembly 2202 on each side face 2215 of the outer circumferential surface 2213, the second insulating sheet 2312 can only cover at least part of the region of the second electrode assembly 2202 in the side face 2215 of the outer circumferential surface 2213, without covering the region of the first electrode assembly 2201 in the side face 2215 of the outer circumferential surface 2213, and the second insulating sheet 2312 covers the first insulating sheet 2311 on each side face 2215 of the outer circumferential surface 2213.

[0173] As shown in Figure 16 In the case where the first insulating sheet 2311 covers the region of the first electrode assembly 2201 and at least part of the region of the second electrode assembly 2202 on each side face 2215 of the outer circumferential surface 2213, the second insulating sheet 2312 can only cover at least part of the region of the second electrode assembly 2202 in the side face 2215 of the outer circumferential surface 2213, without covering the region of the first electrode assembly 2201 in the side face 2215 of the outer circumferential surface 2213, and the second insulating sheet 2312 covers the first insulating sheet 2311 on each side face 2215 of the outer circumferential surface 2213. Figure 15Different is that, at each side surface 2215 of the outer peripheral surface 2213, the first insulating sheet 2311 covers the second insulating sheet 2312.

[0174] As shown in FIG. 1, at each side surface 2215 of the outer peripheral surface 2213, the first insulating sheet 2311 covers the region of the first electrode assembly 2201 and at least part of the region of the second electrode assembly 2202, and the second insulating sheet 2312 can cover the region of the second electrode assembly 2202 and at least part of the region of the first electrode assembly 2201 in the side surface 2215 of the outer peripheral surface 2213, so as to increase the size of the overlapping region between the two insulating sheets 231, and improve the structural stability and insulation effect. Figure 17

[0175] It should be understood that the positions of the overlapping regions of the two insulating sheets 231 on the two side surfaces 2215 of the outer peripheral surface 2213 can be the same or different. For example, as shown in FIG. 1, the positions of the overlapping regions of the two insulating sheets 231 on the two side surfaces 2215 of the outer peripheral surface 2213 can be completely the same, so that the electrode assembly set 22 wrapped by the first insulating film 23 is a symmetrical structure, which is convenient for processing and can improve the structural stability. Figures 15 to 17

[0176] The above describes the manner in which the first insulating film 23 covers the outer peripheral surface 2213 of the embodiment of the application, and the following describes the manner in which the first insulating film 23 covers other regions of the main body part 221 of the embodiment of the application in combination with the drawings.

[0177] In some embodiments, the main body part 221 further comprises a second end surface 2212 opposite to the first end surface 2211, and the outer peripheral surface 2213 connects the first end surface 2211 and the second end surface 2212, and the first insulating film 23 covers at least part of the region of the second end surface 2212, so as to isolate the second end surface 2212 from the shell 21.

[0178] In some embodiments, as shown in FIG. 1, the first insulating film 23 can cover the entire region of the second end surface 2212, so as to isolate the second end surface 2212 from the shell 21 by the first insulating film 23. Figure 4 Figure 5 In some embodiments, different from FIG. 1, the first insulating film 23 can also cover a partial region of the second end surface 2212.

[0179] Figure 4 Figure 5

[0180] Figure 18 FIG. 1 shows a schematic cross-sectional view of a battery monomer 20 of an embodiment of the application. For example, the battery monomer 20 shown in FIG. 1 can be Figure 18 Figure 1 Figure 2 ​​​​​​​​Another possible implementation of the battery cell 20 is shown, and Figure 18 The cross section is perpendicular to the length direction X of the battery cell 20. Figure 19 Another partial cross-sectional view of the battery cell 20 is shown, for example, Figure 19 may be Figure 18 A partial enlarged view of the area near the lower partition 24 is shown.

[0181] In some embodiments, as shown in Figure 18 and Figure 19 The first insulating film 23 is adhered to and covers the edge area 22122 of the second end surface 2212. Exemplarily, the first insulating film 23 includes a first portion 233 and a second portion 234, the first portion 233 extends along the height direction Z of the battery cell 20 and is used to cover the entire area of the outer peripheral surface 2213, and the second portion 234 is bent relative to the first portion 233 and is used to cover the edge area 22122 of the second end surface 2212.

[0182] As shown in Figure 18 and Figure 19 The first portion 233 and the second portion 234 of the first insulating film 23 are relatively bent, and when the first insulating film 23 is adhered, the first insulating film 23 can be wrapped around the outer peripheral surface 2213, so that the first portion 233 of the first insulating film 23 covers the entire area of the outer peripheral surface 2213 to isolate the outer peripheral surface 2213 of the main body 221 and the shell 21; and the part exceeding the outer peripheral surface 2213 is bent to the second end surface 2212, so that the second portion 234 of the first insulating film 23 covers the edge area 22122 of the second end surface 2212.

[0183] In some embodiments, the battery cell 20 further includes a partition 24, the partition 24 is adhered to and covers the area of the second end surface 2212 which is not covered by the first insulating film 23, and the partition 24 covers the first insulating film 23. The partition 24 of the embodiments of the present application is adhered to and covers the area of the second end surface 2212 which is not covered by the first insulating film 23, that is, the partition 24 is located at least in the area of the second end surface 2212 which is not covered by the first insulating film 23; further, the partition 24 can also cover the area of the second end surface 2212 which is covered by the first insulating film 23, and the partition 24 covers the first insulating film 23, that is, the first insulating film 23 on the surface of the second end surface 2212 is located between the partition 24 and the second end surface.

[0184] The first insulating film 23 of the embodiment of the present application covers part of the second end surface 2212 of the main body portion 221, rather than the entire second end surface 2212, which can reduce the weight and space occupied by the first insulating film 23, and thus reduce the weight of the battery monomer 20 and improve the space utilization of the battery monomer 20. Meanwhile, the separator 24 with the adhesive is attached to at least part of the second end surface 2212, and the separator 24 covers at least part of the first insulating film 23 located on the second end surface 2212, so that the separator 24 can be used together with the first insulating film 23 to isolate the second end surface 2212 of the electrode assembly set 22 and the housing 21. In addition, the separator 24 can be fixed by being attached, which is convenient for processing and can improve the processing efficiency of the battery monomer 20.

[0185] Figure 20 A schematic view of the second end surface 2212 of the main body portion 221 to which the first insulating film 23 is attached is shown. In some embodiments, as shown in Figure 20 the second end surface 2212 includes a middle region 22121 and an edge region 22122 surrounding the middle region 22121, and the first insulating film 23 covers the edge region 22122 of the second end surface 2212 but does not cover the middle region 22121 of the second end surface 2212, i.e., the middle region 22121 of the second end surface 2212 is a region of the second end surface 2212 that is not covered by the first insulating film 23, and the edge region 22122 of the second end surface 2212 is a region of the second end surface 2212 that is covered by the first insulating film 23. The first insulating film 23 only covers part of the second end surface 2212, which can isolate the second end surface 2212 from the housing 21 by the separator 24, and can also reduce the coverage area of the first insulating film 23, reduce the weight, and improve the energy density of the battery monomer 20.

[0186] In some embodiments, the shape and size of the middle region 22121 of the second end surface 2212 can be set according to actual application. For example, the shape of the region 22121 of the second end surface 2212 can be the same as that of the second end surface 2212. The edge region 22122 of the second end surface 2212 is a region of the second end surface 2212 other than the middle region 22121, and the edge region 22122 of the second end surface 2212 surrounds the middle region 22121 of the second end surface 2212.

[0187] As shown in Figures 18 to 20 the first portion 233 of the first insulating film 23 covers the outer peripheral surface 2213, and the first insulating film 23 is bent at the intersection of the outer peripheral surface 2213 and the second end surface 2212, so that the second portion 234 is bent to the second end surface 2212, so that the second portion 234 of the first insulating film 23 covers the edge region 22122 of the second end surface 2212 and exposes the middle region 22121 of the second end surface 2212.

[0188] In some embodiments, the first insulating film 23 is bonded to the insulating member 25, so that the insulating member 25 and the first insulating film 23 are fixed to each other, to further improve the stability of the various components inside the battery monomer 20. As shown, in a direction perpendicular to the first end surface 2211, the edge of the first portion 233 facing the cover plate 212 extends beyond the first end surface 2211, so that the first portion 233 is fixedly attached to the insulating member 25. For example, taking the direction perpendicular to the first end surface 2211 as the height direction Z of the battery monomer 20, in the height direction Z, the upper edge of the first portion 233 extends beyond the first end surface 2211 and can extend to the insulating member 25, so that the edge of the first portion 233 can be fixedly attached to the insulating member 25, which can further improve the insulation performance and further improve the structural stability of the battery monomer 20. Moreover, since the first insulating film 23 is provided with an adhesive, the first insulating film 23 and the insulating member 25 do not need to be fixed by additional methods such as heat melting, which can improve the processing efficiency. Figures 18 to 20

[0189] It should be understood that the size of the first insulating film 23 of the embodiments of the present application can be set according to actual application. For example, the thickness of the first insulating film 23 can be in the range of [35um, 80um]. The thickness of the first insulating film 23 is set to be greater than or equal to 35um, so that the first insulating film 23 is not easily damaged, which can improve the reliability of the first insulating film 23 and improve the insulation performance of the first insulating film 23; at the same time, the thickness of the first insulating film 23 is set to be less than or equal to 80um, which can reduce the space occupied by the first insulating film 23 and improve the energy density of the battery monomer 20, under the condition that the strength of the first insulating film 23 meets the design requirements.

[0190] Further, the thickness of the first insulating film 23 can also be in the range of [40um, 55um], to balance the relationship between the structural strength of the first insulating film 23 and the energy density of the battery monomer 20.

[0191] In some embodiments, the thickness of the first insulating film 23 can also be other values. For example, the thickness of the first insulating film 23 can also be any one of the following values or between any two of the following values: 35um, 38um, 40um, 43um, 45um, 48um, 50um, 53um, 55um, 58um, 60um, 63um, 65um, 68um, 70um, 73um, 75um, 78um and 80um.

[0192] ​It should be understood that the material of the first insulating film 23 in this embodiment can be any insulating material to suit different application scenarios. For example, the material of the first insulating film 23 includes a blue film, that is, the first insulating film 23 can be a blue film with an adhesive layer. Compared with the original use of a mylar film to wrap the electrode assembly 22, this blue film is thinner, and its structural strength and insulation performance can still meet the design requirements. The thinner blue film can reduce the space occupied and increase the energy density of the battery cell 20.

[0193] In some embodiments, the material of the blue film mainly includes polyethylene terephthalate (PET) so that the blue film is suitable for battery cells 20 with different chemical systems, making it easy to process and implement.

[0194] The separator 24 of the present application embodiment will now be described with reference to the accompanying drawings.

[0195] It should be understood that the separator 24 in the embodiments of this application can be used to elevate the electrode assembly 22 to reduce the impact of the rounded corners of the housing 21 on the internal electrode assembly 22.

[0196] In some embodiments, the housing 21 includes an intersecting second wall 202 and a third wall 203 connected by a fillet 204, with the second end face 2212 facing the third wall 203. The thickness T of the separator 24 is greater than or equal to the radius R of the fillet 204 to elevate the electrode assembly 22 and reduce interference at the edge portion of the electrode assembly 22 of the fillet 204.

[0197] like Figure 19 As shown, taking the second wall 202 as any side wall of the housing 211 as an example, the third wall 203 is the bottom wall 2112 of the housing 211, and the partition 24 is disposed facing the bottom wall 2112 of the housing 211. When the thickness T of the partition 24 is greater than or equal to the radius R of the fillet 204, and the electrode assembly 22 is disposed above the partition 24, the approximately right-angled corner region of the electrode assembly 22 extends beyond the region of the fillet 204. For example, this corner region can be the intersection of the second end face 2212 and the outer peripheral face 2213 of the main body 221. Therefore, the influence of the fillet 204 on the electrode assembly 22 can be reduced, and the performance of the electrode assembly 22 can be improved.

[0198] In some embodiments, the thickness T of the separator 24 can be set within a range according to the actual application. For example, the thickness T of the separator 24 is related to the radius R of the fillet 204.

[0199] In some embodiments, the thickness T of the separator 24 is in the range of [0.25mm, 0.8mm]. The thickness T of the separator 24 is set to be greater than or equal to 0.25mm to elevate the electrode assembly set 22 and improve the structural strength of the separator 24. The thickness T of the separator 24 is set to be less than or equal to 0.8mm to reduce the space occupied by the separator 24 and improve the energy density of the battery cell 20.

[0200] Further, the thickness T of the separator 24 can also be in the range of [0.3mm, 0.5mm] to balance the structural strength of the separator 24 and the energy density of the battery cell 20.

[0201] In some embodiments, the thickness T of the separator 24 can also be other values. For example, the thickness T of the separator 24 can also be any one of the following values or between any two of the following values: 0.25mm, 0.28mm, 0.3mm, 0.33mm, 0.35mm, 0.38mm, 0.4mm, 0.43mm, 0.45mm, 0.48mm, 0.5mm, 0.53mm, 0.55mm, 0.58mm, 0.6mm, 0.63mm, 0.65mm, 0.68mm, 0.7mm, 0.73mm, 0.75mm, 0.78mm and 0.8mm.

[0202] Figure 21 An internal structure diagram of a battery cell 20 according to another embodiment of the present application is shown, for example, the battery cell 20 can be a cylindrical battery cell. Figure 21 The battery cell 20 shown can be a cylindrical battery cell. Figure 1 The battery cell 20 shown can be a cylindrical battery cell. Figure 2 Another possible implementation of the battery cell 20 is shown. Figure 22 A top view diagram of the separator 24 according to an embodiment of the present application is shown, for example, Figure 22 The diagram can be of the surface of the separator 24 facing the second end surface 2212. Figure 23 A bottom view diagram of the electrode assembly set 22 to which the separator 24 and the first insulating film 23 are attached according to an embodiment of the present application is shown, for example, Figure 23 The diagram can be of the second end surface 2212 to which the separator 24 and the first insulating film 23 are attached.

[0203] In some embodiments, the surface of the middle region 241 of the separator 24 facing the second end face 2212 is planar. By ensuring that at least the surface of the middle region 241 of the separator 24 facing the second end face 2212 is planar, the stability between the separator 24 and the electrode assembly 22 to which the first insulating film 23 is adhered can be improved. Furthermore, the middle region 241 of the separator 24 may also have an adhesive to facilitate the adhesion of the separator 24 to the second end face 2212, thereby improving the stability and insulation performance of the separator 24.

[0204] like Figures 21 to 23 As shown, the specific shape and size of the middle region 241 of the separator 24 can be set according to the actual application. For example, the shape of the middle region 241 of the separator 24 can be consistent with or similar to the outline of the separator 24.

[0205] In some embodiments, an adhesive is provided on the entire surface of the separator 24 facing the second end face 2212 to further improve the connection reliability between the separator 24 and the second end face 2212, thereby improving the insulation effect of the separator 24.

[0206] It should be understood that the shape of the separator 24 in this embodiment can be set according to actual application. For example, as Figures 18 to 19 As shown, the surface of the separator 24 facing the second end face 2212 can be a plane or a near-plane. For example, the separator 24 can be a flat plate structure, which is convenient for processing and allows the second end face 2212 to fit tightly with the surface of the separator 24 facing the second end face 2212, thereby improving structural stability. Furthermore, when the surface of the separator 24 facing the second end face 2212 can be a plane or a near-plane, adhesive can be provided on the entire area of ​​the surface of the separator 24 facing the second end face 2212, or only on the surface of the middle region 241 of the separator 24 facing the second end face 2212. This embodiment is not limited to this.

[0207] For example, unlike Figures 18 to 19 As shown, a portion of the surface of the separator 24 facing the second end face 2212 can be planar, while another portion can be non-planar. This embodiment is not limited to this.

[0208] In some embodiments, such as Figures 21 to 23As shown, the edge region 242 of the partition 24 includes a curved portion 2421, which includes a convex structure 24211 protruding towards the second end face 2212 and a concave structure 24212 protruding away from the second end face 2212. The edge region 242 of the partition 24 is a part of the partition 24 other than the middle region 241, and surrounds the middle region 241 of the partition 24.

[0209] The surface of the middle region 241 of the partition 24 towards the second end face 2212 is planar, which can improve the structural stability between the partition 24 and the electrode assembly set 22. The curved portion 2421 is arranged at the edge region 242 of the partition 24, so that there is more gap between the partition 24 and the second end face 2212, which is conducive to the flow of electrolyte from the concave-convex gap of the curved portion 2421 to the area of the second end face 2212, improves the wettability of the electrode assembly set 22, and improves the electrical performance of the battery cell 20.

[0210] That is, the edge region 242 of the partition 24 is at least partially arranged in a wavy shape.

[0211] It should be understood that the number, size and position of the curved portion 2421 included in the edge region 242 of the partition 24 in the embodiments of the present application can be set according to actual application.

[0212] In some embodiments, the edge region 242 of the partition 24 includes two curved portions 2421 arranged opposite along the width direction of the second end face 2212. The width direction of the second end face 2212 is the direction in which the size of the second end face 2212 is relatively small, for example, the size of the width direction of the second end face 2212 is smaller than the size of the length direction thereof. For example, as shown in Figures 21 to 23 For example, as shown in the second end face 2212, the width direction of the battery cell 20 is the width direction Y, and the edge region 242 of the partition 24 includes two opposite curved portions 2421, each curved portion 2421 extends along the length direction of the second end face 2212, i.e., along the length direction X of the battery cell 20. Therefore, the length of each curved portion 2421 is relatively large, so that there is more gap between the partition 24 and the second end face 2212, which is more conducive to the wettability of the electrolyte; and the two curved portions 2421 are symmetrically distributed, which can improve the structural stability.

[0213] In some embodiments, the part of the edge region 242 of the partition 24 other than the curved portion 2421 is a planar portion 2422, and the surface of the planar portion 2422 towards the second end face 2212 is planar. For example, as shown in Figures 21 to 23As shown, by setting the flat portion 2422, the stability and insulation between the separator 24 and the electrode assembly set 22 can be further increased.

[0214] Alternatively, the edge region 242 of the separator 24 can also not be provided with the flat portion 2422, for example, the entire region of the edge region 242 of the separator 24 is the curved portion 2421, so as to improve the efficiency of the electrolyte infiltrating the electrode assembly set 22.

[0215] In some embodiments, the surface of the curved portion 2421 facing the second end face 2212 can also be provided with an adhesive, so that the convex structure 24211 of the curved portion 2421 protruding towards the second end face 2212 can be pasted to the second end face 2212, so as to further improve the stability and insulation between the separator 24 and the electrode assembly set 22.

[0216] It should be understood that the separator 24 and the first insulating film 23 of the embodiments of the present application can be pasted to the second end face 2212 by an adhesive, and the material of the adhesive of the separator 24 and the material of the adhesive of the first insulating film 23 can be set according to actual application. For example, the adhesive of the separator 24 and the adhesive of the first insulating film 23 can be selected according to the material of the electrolyte inside the battery monomer 20, so as to reduce the influence of the electrolyte on the stability of the adhesive pasting. For another example, the material of the adhesive of the separator 24 and the material of the adhesive of the first insulating film 23 can be the same or different, and the embodiments of the present application are not limited thereto.

[0217] In some embodiments, along the length direction of the second end face 2212, the length L1 of the curved portion 2421 is greater than the length L2 of the middle region 22121 of the second end face 2212. As shown, Figures 21 to 23 For example, along the length direction of the second end face 2212, the length L1 of each curved portion 2421 can be slightly greater than the length L2 of the middle region 22121 of the second end face 2212, so as to increase the gap between the separator 24 and the second end face 2212, and further improve the infiltration efficiency.

[0218] In some embodiments, along the width direction of the second end face 2212, the curved portion 2421 covers at least part of the edge region 22122 of the second end face 2212 and part of the middle region 22121 of the second end face 2212. As shown, Figures 21 to 23As shown, taking the length direction of the second end surface 2212 as an example of the length direction X of the battery cell, the bending portion 2421 can cover the region where the edge region 22122 of the second end surface 2212 and the middle region 22121 of the second end surface 2212 meet, i.e., the edge of the bending portion 2421 toward the middle region 241 of the separator 24 exceeds the edge of the edge region 22122 of the second end surface 2212 toward the middle region 22121 of the second end surface 2212, so that more electrolyte can enter the middle region 22121 of the second end surface 2212 that is not covered by the first insulating film 23 through the bending portion 2421, thereby improving the impregnation efficiency of the electrode assembly set 22 and the performance of the battery cell 20.

[0219] It should be understood that the middle region 22121 of the second end surface 2212 is the region of the second end surface 2212 that is not covered by the first insulating film 23, and accordingly, the edge region 22122 of the second end surface 2212 is the region of the second end surface 2212 that is covered by the first insulating film 23, which surrounds the middle region 22121 of the second end surface 2212.

[0220] According to some embodiments of the present application, the present application also provides a battery apparatus, comprising the battery cell 20 of any of the above-mentioned embodiments.

[0221] The battery apparatus mentioned in the embodiments of the present application can include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly can include a plurality of battery cells connected in series, in parallel, or in a mixed connection through a busbar component.

[0222] In some embodiments, the battery cell assembly is generally formed by arranging a plurality of battery cells.

[0223] As an example, the battery cell assembly can be a battery module formed by arranging and fixing a plurality of battery cells into an independent module. As an example, the battery module can be formed by bundling a plurality of battery cells with a cable tie.

[0224] In some embodiments, the battery apparatus can be a battery pack including a box and one or more battery cell assemblies accommodated in the box.

[0225] As an example, the battery cell assembly can be a battery module, and the battery cell assembly can be accommodated in the box by fixing the battery module in the box.

[0226] As an example, the battery cell assembly can also be housed in the case by directly fixing a plurality of battery cells to the case.

[0227] As an example, the case can include a first case and a second case. The first case and the second case are fastened so that an inner portion of the case forms a closed space to receive the battery cell assembly. The closed here means covered or closed, which can be sealed or unsealed. The first case can be a top cover or a bottom plate.

[0228] As an example, the case can include a top cover, a frame and a bottom plate. The top cover and the bottom plate are connected with the frame respectively so that an inner portion of the case forms a closed space to receive the battery cell assembly.

[0229] In some embodiments, the case can be part of a chassis structure of a vehicle. For example, part of the case can be at least part of a bottom plate of the vehicle, or part of the case can be at least part of a cross beam and a longitudinal beam of the vehicle.

[0230] According to some embodiments of the present application, the present application also provides an electrical equipment, which includes the battery of any of the above-mentioned solutions, and the battery is used to provide electrical energy for the electrical equipment.

[0231] The electrical equipment can be any device or system that uses a battery. For example, a mobile phone, a portable device, a notebook computer, an electric vehicle, an electric toy, an electric tool, a vehicle, a ship and a spacecraft, etc. For example, the spacecraft includes an airplane, a rocket, a space shuttle and a spacecraft, etc.

[0232] The embodiments of the present application provide a storage device, which includes one or more battery clusters to improve the voltage and capacity of the storage device. The battery cluster can include a plurality of battery devices, and the plurality of battery devices are connected in series through a busbar component to improve the voltage of the storage device. When the storage device includes a plurality of battery clusters, the plurality of battery clusters are connected in parallel to improve the capacity of the storage device.

[0233] The storage device can be used in a storage power station, a wind power system, a solar power system, a mobile power system or a temporary power supply system, etc. The storage device can store electrical energy as needed and output the electrical energy at an appropriate time. For example, the storage device can store electrical energy during a low electricity consumption period, and provide electrical energy for related users or electrical devices during a high electricity consumption period. The storage system provided by the embodiments of the present application can be any power system that needs to use a storage device.

[0234] In some embodiments, the storage device is a storage container or a storage cabinet.

[0235] In some embodiments, the storage device can include a cabinet body and one or more battery clusters, and the battery clusters are housed in the cabinet body.

[0236] In some embodiments, the energy storage device can include a thermal management module, a master control module, a general control module, a power distribution module, a fire control module, and the like.

[0237] As an example, the thermal management module can include a liquid cooling unit, which provides cooling liquid to each battery device through a pipeline for adjusting the temperature of the battery cell.

[0238] As an example, the master control module can serve as a battery management unit of the battery cluster for monitoring and managing the battery cluster. The master control module can monitor information such as current, voltage, power, or temperature of the battery cluster. For example, the charging and discharging current, voltage, and the like of the battery cluster can be controlled. The master control module includes a slave battery management unit (SBMU), a fusion switch, and the like.

[0239] As an example, the general control module can serve as a battery management unit of the energy storage device for monitoring and managing the energy storage device. The general control module can monitor information such as current, voltage, power, state of charge, or temperature of the energy storage device. For example, the charging and discharging current, voltage, and the like of the energy storage device can be controlled. As an example, the general control module includes an insulation monitoring module (IMM), a master battery management unit (MBMU), an Ethernet (ETH) and fiber conversion module, and the like.

[0240] As an example, the fire control system includes a control panel, a detector, an alarm device, and the like, for detecting, alarming, or extinguishing the energy storage system.

[0241] As an example, the power distribution device can be used to distribute power to the power consumption module of the energy storage device.

[0242] According to some embodiments of the present application, the present application also provides an energy storage system including the energy storage device of any one of the above solutions. In some embodiments, the energy storage system can include one or more energy storage devices and a power conversion device (PCS) connected between the power generation device and the energy storage device. The power generation device is used to generate electric energy, and the electric energy generated by the power generation device can be stored in the energy storage device through the power conversion device. As an example, the power generation device 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 is not limited in the present application.

[0243] According to some embodiments of the present application, a charging network is provided. The charging network comprises a charging pile and an energy storage device, the charging pile is electrically connected with the energy storage device, and the energy storage device is configured to provide electric energy for the charging pile. The charging pile is electrically connected with a battery device in the energy storage device through a cable, and the battery device can provide the stored electric energy to the charging pile. The charging pile has one or more connectors configured to be connected with an electric device (e.g., a vehicle) so as to provide electric energy to the electric device.

[0244] The energy storage device can be located inside the charging pile (e.g., a charging and storage integrated machine) or outside the charging pile.

[0245] According to some embodiments of the present application, referring to Figures 8 to 19 A battery cell 20 is provided, comprising: a housing 21 having a receiving cavity; an electrode terminal 214 disposed on a first wall 201 of the housing 21; an electrode assembly set 22 received in the receiving cavity, the electrode assembly set 22 comprising at least one electrode assembly 220, the electrode assembly set 22 comprising a main body portion 221 and a tab 222, the main body portion 221 comprising a first end face 2211 and an outer peripheral surface 2213 intersecting the first end face 2211 and surrounding the first end face 2211, the tab 222 being located on the first end face 2211, the first end face 2211 facing the first wall 201; a current collecting member 27 electrically connecting the electrode terminal 214 and the tab 222; a first insulating film 23 covering the outer peripheral surface 2213; and a second insulating film 26 comprising a body portion 261 and an extension portion 262, the body portion 261 being disposed between the current collecting member 27 and the first wall 201 to separate the current collecting member 27 and the first wall 201, the extension portion 262 covering at least a part of the outer peripheral surface 2213, and the first insulating film 23 wrapping and fixing the extension portion 262.

[0246] The second insulating film 26 comprises two extension portions 262 oppositely arranged, each of the two extension portions 262 covering at least a part of two large faces 2214 of the outer peripheral surface 2213, the large faces 2214 of the outer peripheral surface 2213 being the faces with the largest area. The battery cell further comprises: an insulating member 25 fixed to the first wall 201 and located between the first wall 201 and the first end face 2211, and the first insulating film 23 being fixed to the insulating member 25. The body portion 261 is disposed between the current collecting member 27 and the insulating member 25. The insulating member 25 comprises a first electrode lead-out hole 251, and the electrode terminal 214 is connected with the current collecting member 27 through the first electrode lead-out hole 251.

[0247] The current collecting member 27 includes an electrode terminal connecting portion 271, and the body portion 261 includes a second electrode lead-out hole 2611 through which the electrode terminal 214 and / or the electrode terminal connecting portion 271 passes to connect the electrode terminal 214 and the electrode terminal connecting portion 271. The current collecting member 27 includes a tab connecting portion 272 for electrically connecting with the tab 222, and the tab connecting portion 272 is located between the body portion 261 and the tab 222.

[0248] The battery cell 20 further includes a third insulating film 28 including a first region 281 and a second region 282, the first region 281 being bonded to the tab connecting portion 272, and the second region 282 being attached to and covering a partial region of the outer circumferential surface 2213. The second insulating film 26 covers the third insulating film 28, and the extension portion 262 covers the outer circumferential surface 2213 along the thickness direction of the first wall 201, and the length of the outer circumferential surface 2213 covered by the extension portion 262 is greater than the length of the outer circumferential surface 2213 covered by the second region 282. The melting point of the third insulating film 28 is greater than the melting point of the second insulating film 26.

[0249] The battery cell further includes a pressure relief mechanism 213 disposed on the first wall 201, and the body portion 261 further includes a pressure relief hole 2612 corresponding to the pressure relief mechanism 213. The battery cell further includes a liquid injection structure 215 disposed on the first wall 201, and the body portion 261 further includes a liquid injection hole 2613 corresponding to the liquid injection structure 215.

[0250] The ratio of the length of the outer circumferential surface 2213 covered by the extension portion 262 to the length of the outer circumferential surface 2213 along the thickness direction of the first wall 201 is in the range of [0.08, 0.25].

[0251] The electrode assembly 220 has a stacked structure. The first insulating film 23 includes at least one insulating sheet 231, and the first insulating film 23 is folded and attached to the outer circumferential surface 2213. The first insulating film 23 includes two insulating sheets 231, and the two insulating sheets 231 respectively cover two large faces 2214 of the outer circumferential surface 2213 and overlap and are bonded at two side faces 2215 of the outer circumferential surface 2213 to cover the outer circumferential surface 2213. The area of the side face 2215 of the outer circumferential surface 2213 is smaller than the area of the large face 2214 of the outer circumferential surface 2213.

[0252] The body portion 221 further includes a second end surface 2212 opposite the first end surface 2211, and an outer peripheral surface 2213 connecting the first end surface 2211 and the second end surface 2212, and the first insulating film 23 covers at least a part of the second end surface 2212. The first insulating film 23 adheres to and covers an edge region 22122 of the second end surface 2212; the battery cell further includes a separator 24 adhering to and covering a region of the second end surface 2212 that is not covered by the first insulating film 23, and the separator 24 covers the first insulating film 23.

[0253] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements 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. In particular, 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 herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized by, The battery cell comprises: a housing (21) having a receiving cavity; an electrode terminal (214) provided on a first wall (201) of the housing (21); a set of electrode assemblies (22) received in the receiving cavity, the set of electrode assemblies (22) comprising at least one electrode assembly (220), the electrode assembly (220) comprising a main body portion (221) and a tab (222), the main body portion (221) comprising a first end face (2211) and a peripheral face (2213) intersecting the first end face (2211) and surrounding the first end face (2211), the tab (222) being located on the first end face (2211), the first end face (2211) facing the first wall (201); a current collecting member (27) for electrically connecting the electrode terminal (214) and the tab (222); a first insulating film (23) covering the peripheral face (2213); a second insulating film (26) comprising a body portion (261) and an extension portion (262), the body portion (261) being provided between the current collecting member (27) and the first wall (201) to separate the current collecting member (27) and the first wall (201), the extension portion (262) covering at least a part of the peripheral face (2213), the first insulating film (23) wrapping and fixing the extension portion (262).

2. The battery cell of claim 1, wherein, The second insulating film (26) comprises two extension portions (262) provided oppositely, each of the two extension portions (262) covering at least a part of two major faces (2214) of the peripheral face (2213), the major faces (2214) of the peripheral face (2213) being the faces with the largest area of the peripheral face (2213).

3. The battery cell of claim 1, wherein, The battery cell further comprises: an insulating member (25) fixed to the first wall (201) and located between the first wall (201) and the first end face (2211), the first insulating film (23) being fixed to the insulating member (25).

4. The battery cell of claim 3, wherein, The body portion (261) is provided between the current collecting member (27) and the insulating member (25).

5. The battery cell of claim 3, wherein, The insulating member (25) comprises a first electrode lead-out hole (251), the electrode terminal (214) being connected to the current collecting member (27) through the first electrode lead-out hole (251).

6. The battery cell of claim 1, wherein, The current collecting member (27) comprises an electrode terminal connecting portion (271), the body portion (261) comprises a second electrode lead-out hole (2611), the electrode terminal (214) and / or the electrode terminal connecting portion (271) passing through the second electrode lead-out hole (2611) to connect the electrode terminal (214) and the electrode terminal connecting portion (271).

7. The battery cell of claim 1, wherein, The current collecting member (27) includes a tab connecting portion (272) for electrically connecting with the tab (222), and the tab connecting portion (272) is located between the body portion (261) and the tab (222).

8. The battery cell of claim 7, wherein, The battery cell further includes: A third insulating film (28) includes a first region (281) and a second region (282) which are relatively bent, the first region (281) is bonded to the tab connecting portion (272), and the second region (282) is bonded to and covers a partial region of the outer circumferential surface (2213), the second insulating film (26) covers the third insulating film (28), The length of the extension portion (262) covering the outer circumferential surface (2213) is greater than the length of the second region (282) covering the outer circumferential surface (2213) along the thickness direction of the first wall (201).

9. The battery cell of claim 8, wherein, The melting point of the third insulating film (28) is greater than the melting point of the second insulating film (26).

10. The battery cell of claim 1, wherein, The battery cell further includes: A pressure relief mechanism (213) is arranged on the first wall (201), and the body portion (261) further includes a pressure relief hole (2612) arranged corresponding to the pressure relief mechanism (213).

11. The battery cell of claim 1, wherein, The battery cell further includes: An injection structure (215) is arranged on the first wall (201), and the body portion (261) further includes an injection hole (2613) arranged corresponding to the injection structure (215).

12. The battery cell of claim 1, wherein, The ratio of the length of the extension portion (262) covering the outer circumferential surface (2213) to the length of the outer circumferential surface (2213) along the thickness direction of the first wall (201) is in the range of [0.08, 0.25].

13. The battery cell of any one of claims 1 to 12, wherein, The electrode assembly (220) is a stacked structure.

14. The battery cell of claim 13, wherein, The electrode assembly (220) includes a first surface (2201) and a second surface (2202) arranged oppositely along the thickness direction of the electrode assembly (220), and further includes a plurality of fixing structures (2203) arranged at intervals, each of the plurality of fixing structures (2203) extends from the edge of the first surface (2201) to the edge of the second surface (2202) along the thickness direction of the electrode assembly (220), and the second insulating film (26) covers the plurality of fixing structures (2203).

15. The battery cell of any one of claims 1 to 12, wherein, The first insulating film (23) includes at least one insulating sheet (231), and the first insulating film (23) is folded and bonded to the outer circumferential surface (2213).

16. The battery cell of claim 15, wherein, The first insulating film (23) includes two insulating sheets (231) respectively covering two large faces (2214) of the outer peripheral face (2213) and overlapping and bonding at two side faces (2215) of the outer peripheral face (2213) to cover the outer peripheral face (2213), the side faces (2215) of the outer peripheral face (2213) having an area smaller than that of the large faces (2214) of the outer peripheral face (2213).

17. The battery cell of claim 16, wherein, The electrode assembly set (22) includes a first electrode assembly (2201) and a second electrode assembly (2202), and the insulating sheet (231) pasted to the side face of the outer peripheral face of the first electrode assembly (2201) is pasted to the side face of the outer peripheral face of the second electrode assembly (2202).

18. The battery cell of any one of claims 1-12, wherein, The main body part (221) further includes a second end face (2212) opposite to the first end face (2211), the outer peripheral face (2213) connecting the first end face (2211) and the second end face (2212), and the first insulating film (23) covering at least a partial area of the second end face (2212).

19. The battery cell of claim 18, wherein, The first insulating film (23) pastes and covers an edge area (22122) of the second end face (2212). The battery cell further includes: a separator (24) pasting and covering an area of the second end face (2212) not covered by the first insulating film (23), and the separator (24) covering the first insulating film (23).

20. The battery cell of any one of claims 1-12, wherein, The housing (21) includes: a shell (211) having an opening (2111); a cover plate (212) for covering the opening (2111) to form the accommodating cavity, the cover plate (212) including the first wall (201).

21. A battery device, characterized by It includes: a plurality of battery cells according to any one of claims 1 to 20.

22. An energy storage device, comprising: It includes: a plurality of battery cells according to any one of claims 1 to 20 or a plurality of battery devices according to claim 21, the battery cells or the battery devices being used for storing or providing electric energy.

23. An energy storage system characterized by, It includes: a power conversion device; an energy storage device according to claim 22, the power conversion device being used for electrically connecting a power generation device and the energy storage device.

24. A charging network characterized by, It includes: a charging pile; an energy storage device according to claim 22 or an energy storage system according to claim 23, the energy storage device being used for providing electric energy for the charging pile.

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