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 comprises: a housing having an accommodating cavity; the electrode assembly set is arranged in the accommodating cavity, the electrode assembly set comprises a main body part and a tab, the main body part comprises a first end surface, a second end surface and a peripheral surface, the second end surface is opposite to the first end surface, the peripheral surface is connected with the first end surface and the second end surface, and the tab is positioned on the first end surface; a first insulating film adhered to and covering the outer peripheral surface and an edge region of the second end surface; and a separator attached to and covering a region of the second end surface, which is not covered by the first insulating film, and covering the first insulating film. 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 processing efficiency 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. In order to realize the insulation between the electrode assembly and the shell, it is usually necessary to wrap an insulating film on the outer surface of the electrode assembly. How to set the insulating film inside the battery monomer to improve the processing efficiency of the battery monomer 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 processing efficiency of the battery monomer.

[0005] In a first aspect, a battery monomer is provided, comprising: a shell having a receiving cavity; a set of electrode assemblies arranged in the receiving cavity, the set of electrode assemblies comprising at least one electrode assembly, the electrode assembly comprising a main body portion and a tab, the main body portion comprising a first end face, a second end face opposite to the first end face, and an outer peripheral surface connecting the first end face and the second end face, the tab being located at the first end face; a first insulating film adhered to and covering the outer peripheral surface and an edge region of the second end face; and a partition adhered to and covering a region of the second end face not covered by the first insulating film, and the partition covering the first insulating film.

[0006] Therefore, the battery monomer of the embodiments of the present application can effectively isolate the set of electrode assemblies and the shell by directly adhering and fixing the first insulating film to the outer peripheral surface of the main body portion and the edge region of the second end face, and does not need to be fixed by hot melting, reduces the processing steps, is more convenient for processing of the battery monomer, and can improve the processing efficiency of the battery monomer. In addition, the first insulating film covers part of the region of the second end face of the main body portion, rather than the entire region, which can reduce the weight. At the same time, the partition is adhered to and covers the region of the second end face not covered by the first insulating film, and covers the first insulating film adhered to the edge of the second end face. The partition can be used to isolate the second end face of the set of electrode assemblies and the shell, and the partition is fixed by adhesion, which is convenient for processing and can also improve the processing efficiency of the battery monomer.

[0007] In some embodiments, the electrode assembly is a laminated structure. The first insulating film can also be used to fix the electrode assembly set to improve the stability of the electrode assembly set. In particular, when the electrode assembly set includes a plurality of electrode assemblies, the outer circumferential surface of the electrode assembly set is surrounded by the first insulating film, which can increase the structural stability, reduce the misalignment and movement between the plurality of laminated electrode plates, and thus improve the performance of the electrode assembly set.

[0008] 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 the edge of the first surface to the edge of the second surface along the thickness direction of the electrode assembly, and the first insulating film covers the plurality of fixing structures. For a laminated 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 of the embodiments of the present application is at least pasted to the outer circumferential surface of the main body portion of the electrode assembly set, i.e., pasted to the outside of the plurality of fixing structures, which can reduce the movement and misalignment between the plurality of electrode assemblies to further improve the stability of the electrode assembly set.

[0009] In some embodiments, the first insulating film includes at least one insulating sheet, and the first insulating film is folded to wrap the outer circumferential surface. Compared with the way of setting a heat-shrinkable film or the like outside the electrode assembly set, the first insulating film of the embodiments of the present application adopts a sheet structure, at least one insulating sheet can be wrapped and pasted to the outer circumferential surface by folding, which is simple in processing manner and can improve the processing efficiency, and the first insulating film can be more closely attached to the main body portion of the electrode assembly set, which can improve the space utilization of the battery monomer.

[0010] In some embodiments, the first insulating film includes two insulating sheets, the two insulating sheets cover two large faces of the outer circumferential surface and overlap and are bonded at two side faces of the outer circumferential surface to cover the outer circumferential surface, and the area of the side face of the outer circumferential surface is smaller than the area of the large face of the outer circumferential surface. The two large faces of the outer circumferential surface are provided with relatively complete insulating sheets, and the two side faces of the outer circumferential surface are provided with overlapping regions of the two insulating sheets, which is simple in processing operation and facilitates improving the processing efficiency, and can also improve the structural stability.

[0011] In some embodiments, the electrode assembly set includes a first electrode assembly and a second electrode assembly, and the insulating sheet bonded to the side face of the outer circumferential surface of the first electrode assembly is bonded to the side face 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.

[0012] In some embodiments, the surface of the middle region of the separator facing the second end face is planar. By the part being planar, the stability between the separator and the electrode assembly set to which the first insulating film is attached can be improved, thereby improving the insulation performance of the separator.

[0013] In some embodiments, the edge region of the separator comprises a curved portion, the curved portion comprising a protruding structure protruding towards the second end face and a recessed structure protruding away from the second end face. By providing the curved portion in the edge region of the separator, there is more gap between the separator and the second end face, which is conducive to the electrolyte flowing from the concave-convex gap of the curved portion to the region of the second end face, improving the wettability of the electrode assembly set and improving the electrical performance of the battery cell.

[0014] In some embodiments, the edge region of the separator comprises two curved portions arranged opposite along the width direction of the second end face. In this way, the length of each curved portion is large, so that there is more gap between the separator and the second end face, which is more conducive to the wettability of the electrolyte; and the two curved portions are symmetrically distributed, which can improve the structural stability.

[0015] In some embodiments, the part of the edge region of the separator other than the curved portion is a planar portion, and the surface of the planar portion facing the second end face is planar. By providing the planar portion, the stability and insulation between the separator and the electrode assembly set can be further improved.

[0016] In some embodiments, along the length direction of the second end face, the length of the curved portion is greater than the length of the middle region of the second end face; and / or, along the width direction of the second end face, the curved portion covers at least part of the edge region of the second end face and part of the middle region of the second end face. The middle region of the second end face is the region of the second end face that is not covered by the first insulating film. In this way, more electrolyte can enter the middle region of the second end face that is not covered by the first insulating film through the curved portion, thereby improving the wettability efficiency of the electrode assembly set and the performance of the battery cell.

[0017] In some embodiments, the housing comprises: a shell having an opening; a cover plate for covering the opening to form the accommodation cavity, the first end face facing the cover plate and the second end face facing the bottom wall of the shell; and an electrode terminal arranged on the cover plate, which is simple in structure and facilitates installation and processing.

[0018] In some embodiments, the battery monomer further comprises: an insulating piece fixed to the cover plate and located between the cover plate and the first end face, and the first insulating film is bonded to the insulating piece to paste the first insulating film and the insulating piece, which can further improve the insulation performance and further improve the structural stability of the battery monomer. Moreover, since the first insulating film is pasted to the insulating piece, no additional fixing method such as hot melting is needed between the first insulating film and the insulating piece, which can improve the processing efficiency.

[0019] In some embodiments, the battery monomer further comprises: a current collecting member connecting the tab and the electrode terminal; an insulating piece fixed to the cover plate and located between the cover plate and the first end face; and a second insulating film comprising a body part and an extension part, the body part being arranged between the current collecting member and the insulating piece to isolate the current collecting member and the insulating piece, and the extension part covering at least part of the area of the large face of the outer peripheral surface, the first insulating film wrapping and fixing the extension part, the large face of the outer peripheral surface being the face with the largest area of the outer peripheral surface.

[0020] In some embodiments, the shell comprises intersecting first and second walls connected by a fillet, the second end face faces the second wall, and the thickness of the partition piece is greater than or equal to the radius of the fillet to elevate the electrode assembly collection and reduce the interference of the edge part of the electrode assembly collection of the fillet.

[0021] In some embodiments, the thickness of the partition piece is in the range of [0.25mm, 0.8mm]. The thickness of the partition piece is greater than or equal to 0.25mm to elevate the electrode assembly collection and improve the structural strength of the partition piece. The thickness of the partition piece is less than or equal to 0.8mm to reduce the space occupied by the partition piece and improve the energy density of the battery monomer.

[0022] In some embodiments, the thickness of the first insulating film is in the range of [35um, 80um]. The thickness of the first insulating film is greater than or equal to 35um to make the first insulating film not easy to break, which can improve the reliability and insulation performance of the first insulating film. Meanwhile, the thickness of the first insulating film is less than or equal to 80um to reduce the space occupied by the first insulating film and improve the energy density of the battery monomer under the condition that the strength of the first insulating film meets the design requirements.

[0023] In a second aspect, a battery device is provided, comprising: a plurality of battery monomers of the first aspect or any one of the embodiments of the first aspect.

[0024] In a third aspect, there is provided an energy storage device, comprising: a plurality of the battery cell of the first aspect or any one of the embodiments of the first aspect, or the battery device of the second aspect, the battery cell or the battery device being configured to store or provide electrical energy.

[0025] In a fourth aspect, there is provided an energy storage system, comprising: a power conversion device; and the energy storage device of the third aspect, the power conversion device being configured to electrically connect a power generation device and the energy storage device.

[0026] In a fifth aspect, there is provided a charging network, comprising: a charging post; and the energy storage device of the third aspect or the energy storage system of the fourth aspect, the energy storage device being configured to provide electrical energy to the charging post. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 A schematic structural diagram of a battery cell according to an embodiment of the present application;

[0028] Figure 2 A schematic exploded diagram of a partial structure of a battery cell according to an embodiment of the present application;

[0029] Figure 3 A schematic structural diagram of a set of electrode assemblies according to an embodiment of the present application;

[0030] Figure 4 A schematic cross-sectional diagram of an electrode assembly according to an embodiment of the present application;

[0031] Figure 5 A schematic cross-sectional diagram of an electrode assembly according to another embodiment of the present application;

[0032] Figure 6 A schematic front view diagram of an electrode assembly according to an embodiment of the present application;

[0033] Figure 7 A schematic bottom view diagram of an electrode assembly according to an embodiment of the present application;

[0034] Figure 8 A schematic top structural diagram of a set of electrode assemblies wrapped with a first insulating film according to an embodiment of the present application;

[0035] Figure 9 A schematic top structural diagram of a set of electrode assemblies wrapped with a first insulating film according to another embodiment of the present application;

[0036] Figure 10 A schematic top structural diagram of a set of electrode assemblies wrapped with a first insulating film according to another embodiment of the present application;

[0037] Figure 11 A schematic top structural diagram of a set of electrode assemblies wrapped with a first insulating film according to another embodiment of the present application;

[0038] Figure 12 Internal structure of a battery cell according to an embodiment of the present application;

[0039] Figure 13 Cross-sectional view of a battery cell according to an embodiment of the present application;

[0040] Figure 14 Partial cross-sectional view of a battery cell according to an embodiment of the present application;

[0041] Figure 15 View of the second end surface of the main body portion to which the first insulating film is attached according to an embodiment of the present application;

[0042] Figure 16 Internal structure of a battery cell according to another embodiment of the present application;

[0043] Figure 17 Plan view of a separator according to an embodiment of the present application;

[0044] Figure 18 View of the electrode assembly to which the separator and the first insulating film are attached according to an embodiment of the present application;

[0045] Figure 19 Exploded view of a partial structure of a battery cell according to another embodiment of the present application;

[0046] Figure 20 Internal structure of a battery cell according to another embodiment of the present application;

[0047] Figure 21 Cross-sectional view of a battery cell according to another embodiment of the present application;

[0048] Figure 22 Another partial cross-sectional view of a battery cell according to another embodiment of the present application;

[0049] Figure 23 Structure of a second insulating film according to another embodiment of the present application;

[0050] Figure 24 Structure of a current collecting member, a second insulating film, and an insulating member in a battery cell according to another embodiment of the present application;

[0051] Figure 25 Partial cross-sectional view of a battery cell according to still another embodiment of the present application.

[0052] In the drawings, the drawings are not drawn to scale. DETAILED DESCRIPTION

[0053] The technical solutions in the embodiments of the present application will be described below with reference to the drawings.

[0054] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings. Obviously, the described embodiments are only some, 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 effort should fall within the scope of the present application.

[0055] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as those 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 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 the 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, not to describe a particular order or primary and secondary relationship.

[0056] In the present application, the phrase "embodiment" means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of the present application. The phrase appears at various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily independent or alternative to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in the present application can be combined with other embodiments.

[0057] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "mount", "connect", "connection", "attach" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be direct connection, or indirect connection through intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0058] In the present application, the term "and / or" is only a description of the association relationship between the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can represent the existence of A alone, the existence of A and B together, and the existence of B alone. In addition, the character " / " in the present application generally represents an "or" relationship between the associated objects before and after it.

[0059] In the embodiments of the present application, the same reference signs represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of the present 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 present application.

[0060] In the present application, "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0061] In the embodiments of the present application, the battery cell can be a secondary battery, which refers to a battery cell that can be activated by charging after discharging the battery cell.

[0062] 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., which is not limited in the embodiments of the present application.

[0063] The 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 the charging and discharging process of the battery cell, active ions (such as lithium ions) are inserted and extracted between the positive electrode and the negative electrode. The separator is disposed between the positive electrode and the negative electrode, which can prevent the positive and negative electrodes from short-circuiting, and at the same time, the active ions can pass through.

[0064] 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.

[0065] As an example, the positive electrode current collector has two opposite surfaces in its own thickness direction, and the positive electrode active material is disposed on any one or both of the two opposite surfaces of the positive electrode current collector.

[0066] As an example, the positive electrode current collector can adopt a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metal, alloy, surface-treated metal can be used, including but not limited to stainless steel, copper, aluminum, nickel, nickel, titanium, or silver, etc. 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.).

[0067] As an example, the positive electrode active material can include at least one of lithium-containing phosphates, lithium transition metal oxides, and modified compounds of each thereof. However, the present application is not limited to these materials, and other conventional materials that can be used as a battery positive electrode active material can also be used.

[0068] In some embodiments, the negative electrode can be a negative electrode tab, which can include a negative electrode current collector.

[0069] As an example, the negative electrode current collector can employ 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 employed. 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.).

[0070] 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.

[0071] As an example, the negative electrode current collector has two surfaces opposite in the thickness direction thereof, and the negative electrode active material is disposed on either one or both of the two opposite surfaces of the negative electrode current collector.

[0072] As an example, the negative electrode active material can include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc.

[0073] 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 a negative electrode tab, the surface of the foamed metal can not be provided with a negative electrode active material, or of course can be provided with a negative electrode active material.

[0074] As an example, the negative electrode active material can be filled or / and deposited in the negative electrode current collector.

[0075] In some embodiments, the material of the positive electrode current collector can be aluminum, and the material of the negative electrode current collector can be copper.

[0076] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0077] In some embodiments, the separator is a separator film. The present application does not have a particular limitation on the type of the separator film, and any porous structure separator film having good chemical stability and mechanical stability can be selected.

[0078] 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 functions to transport ions and separate the positive electrode and the negative electrode.

[0079] In some embodiments, the battery cell further comprises an electrolyte, which functions to conduct ions between the positive electrode and the negative electrode. The type of electrolyte is not specifically limited in the present application, and can be selected as needed. The electrolyte can be liquid, gel, or solid.

[0080] The electrode assembly can be a wound structure, a stacked structure, or a hybrid structure of a wound structure and a stacked structure.

[0081] In some embodiments, the electrode assembly is a wound structure. The positive electrode sheet and the negative electrode sheet are wound to form the wound structure.

[0082] In some embodiments, the electrode assembly is a stacked structure.

[0083] As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets can be provided, and the plurality of positive electrode sheets and the plurality of negative electrode sheets can be alternately stacked.

[0084] As an example, a plurality of positive electrode sheets can be provided, and the negative electrode sheet can be folded to form a plurality of folded segments that are stacked. One positive electrode sheet can be interposed between adjacent folded segments.

[0085] As an example, the positive electrode sheet and the negative electrode sheet can be folded to form a plurality of folded segments that are stacked.

[0086] As an example, a plurality of separators can be provided, and each of the plurality of separators can be interposed between any adjacent positive electrode sheet or negative electrode sheet.

[0087] As an example, a plurality of separators can be provided, and each of the plurality of separators can be interposed between any adjacent positive electrode sheet or negative electrode sheet.

[0088] In some embodiments, the electrode assembly can have a cylindrical shape, a flat shape, or a polygonal shape.

[0089] In some embodiments, the electrode assembly can be provided with a tab, which can guide current out of the electrode assembly. The tab can include a positive tab and a negative tab.

[0090] In the preparation process of the battery cell, after the electrode assembly is prepared, it needs to be loaded into a metal shell to complete the assembly. In order to realize the insulation between the electrode assembly and the shell, it is usually necessary to wrap an insulating film on the outer surface of the electrode assembly. The existing electrode assembly and the shell are usually insulated by a mylar film, and the mylar film and the insulating piece arranged below the cover plate are usually fixed by a hot melting method. However, the hot melting process increases the cost, and the thickness of the mylar film also occupies the effective space inside the battery cell, reducing the energy density of the battery cell. Therefore, how to set the insulating film inside the battery cell to improve the processing efficiency of the battery cell is an urgent technical problem to be solved.

[0091] The battery cell, the battery device, the energy storage device, the energy storage system and the charging network provided by the embodiments of the present application can solve the above problems. The battery cell of the embodiments of the present application comprises a shell, an electrode assembly set, a first insulating film and a partition piece. The electrode assembly set is arranged in the accommodating 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, a second end face and an outer peripheral surface. The first end face and the second end face are opposite to each other, and the outer peripheral surface connects the first end face and the second end face. The tab is located at the first end face of the main body part. The first insulating film is pasted and covers the outer peripheral surface and the edge region of the second end face. By directly pasting and fixing the first insulating film on the outer peripheral surface and the edge region of the second end face of the main body part, the electrode assembly set and the shell can be effectively isolated, and the fixing by hot melting is not required, the processing steps are reduced, the processing of the battery cell is more convenient, and the processing efficiency of the battery cell can be improved.

[0092] In addition, the first insulating film covers part of the area of the second end face of the main body part, rather than the whole area, so as to reduce the weight. Meanwhile, the partition piece is pasted and covers the area of the second end face which is not covered by the first insulating film, and covers and pastes the first insulating film at the edge of the second end face. The partition piece can be used to isolate the second end face of the electrode assembly and the shell, and the partition piece is fixed by pasting, which is convenient for processing and can improve the processing efficiency of the battery cell.

[0093] Figure 1 A structural schematic diagram of the battery cell 20 of the embodiments of the present application is shown; Figure 2 An exploded schematic diagram of the partial structure of the battery cell 20 of the embodiments of the present application is shown; Figure 3 A structural schematic diagram of the electrode assembly set 22 of the battery cell 20 of the embodiments of the present application is shown. As shown in the figure, Figures 1 to 3 The battery cell 20 of the embodiments of the present application comprises a shell 21, an electrode assembly set 22, a first insulating film 23 and a partition piece 24.

[0094] Specifically, the shell 21 has a receiving cavity, and the electrode assembly set 22 is arranged in the receiving cavity. The electrode assembly set 22 includes a main body part 221 and a tab 222. The main body part 221 includes a first end face 2211, a second end face 2212 opposite to the first end face 2211, and an outer circumferential face 2213 connecting the first end face 2211 and the second end face 2212. The tab 222 is located at the first end face 2211. The first insulating film 23 is attached to and covers the outer circumferential face 2213 and an edge area 22122 of the second end face 2212. The separator 24 is attached to and covers an area of the second end face 2212 that is not covered by the first insulating film 23, and the separator 24 covers the first insulating film 23.

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

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

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

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

[0099] The electrode assembly set 22 of the embodiments of the present application can include a tab 222 and a main body part 221. Specifically, the electrode assembly set 22 can include at least two tabs 222, which can include at least one positive electrode tab 222a and at least one negative electrode tab 222b, each positive electrode tab 222a can be formed by laminating the part of the positive electrode tab of one or more electrode assemblies 220 on which the positive active material layer is not coated, and the part of the corresponding positive electrode tab on which the positive active material layer is coated can be formed by winding or lamination to form the main body part 221 of the electrode assembly set 22; each negative electrode tab 222b can be formed by laminating the part of the negative electrode tab of one or more electrode assemblies 220 on which the negative active material layer is not coated, and the part of the corresponding negative electrode tab on which the negative active material layer is coated can be formed by winding or lamination 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 part of the positive electrode tab on which the positive active material layer is coated and the part of the negative electrode tab on which the negative active material layer is coated of all the electrode assemblies 220.

[0100] The plurality of tabs 222 of the electrode assembly set 22 of the embodiments of the present application can be located at the same end face of the electrode assembly set 22. For example, as shown in Figures 1 to 3 the embodiments of the present application mainly take an example in which all the tabs 222 included in the electrode assembly set 22 are arranged at the first end face 2211 of the main body part 221 of the electrode assembly set 22, but the embodiments of the present application are not limited thereto.

[0101] The main body 221 of the embodiment of the present application further comprises a second end surface 2212, wherein the first end surface 2211 and the second end surface 2212 are two oppositely arranged end surfaces of the main body 221. In addition, the main body 221 further comprises an outer peripheral surface 2213 for connecting the first end surface 2211 and the second end surface 2212. For example, as shown in FIG. 2, taking the approximately cuboid main body 221 as an example, in the case where the first end surface 2211 and the second end surface 2212 are oppositely arranged, the outer peripheral surface 2213 for connecting the first end surface 2211 and the second end surface 2212 can comprise four surfaces, and the outer peripheral surface 2213 surrounds the first end surface 2211 and the second end surface 2212. Figures 1 to 3

[0102] The first insulating film 23 of the embodiment of the present application has an adhesive, so that the first insulating film 23 can be pasted and covered on the outer peripheral surface 2213 and the edge region 22122 of the second end surface 2212 of the main body 221 by the adhesive. Wherein the first insulating film 23 covering the outer peripheral surface 2213 means that the first insulating film 23 is located at least in part of the region of the outer peripheral surface 2213, so as to isolate the part of the region of the electrode assembly set 22 and the shell 21, for example, the first insulating film 23 can cover all the regions of the outer peripheral surface 2213, so as to improve the insulation. The first insulating film 23 covering the edge region 22122 of the second end surface 2212 means that the first insulating film 23 is located in the edge region 22122 of the second end surface 2212, and not in the middle region 22121 of the second end surface 2212.

[0103] By directly pasting and fixing the first insulating film 23 on the outer peripheral surface 2213 and the edge region 22122 of the second end surface 2212 of the main body 221, the electrode assembly set 22 and the shell 21 can be effectively isolated, and the first insulating film 23 does not need to be fixed by hot melting, thereby reducing the processing steps, facilitating the processing of the battery monomer 20, and improving the processing efficiency of the battery monomer 20.

[0104] The partition 24 of the embodiment of the present application pastes and covers the region of the second end surface 2212 which is not covered by the first insulating film 23, that is, the partition 24 is at least located in the region of the second end surface 2212 which is not covered by the first insulating film 23; further, the partition 24 can also cover the region 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.

[0105] ​In this embodiment, the first insulating film 23 covers a portion, rather than the entire, area of ​​the second end face 2212 of the main body 221, which reduces the weight and space occupied by the first insulating film 23, thereby reducing the weight of the battery cell 20 and improving the space utilization of the battery cell 20. At the same time, the separator 24 with adhesive is pasted on at least a portion of the second end face 2212, and the separator 24 covers at least a portion of the first insulating film 23 located on the second end face 2212, so that the separator 24 can be used together with the first insulating film 23 to isolate the second end face 2212 of the electrode assembly 22 and the outer shell 21. Furthermore, the separator 24 can be fixed by adhesive, which facilitates processing and can also improve the processing efficiency of the battery cell 20.

[0106] 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.

[0107] The electrode assembly 220 of any embodiment of this application will now be described with reference to the accompanying drawings.

[0108] 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.

[0109] 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 4 A cross-sectional schematic diagram of the electrode assembly 220 according to an embodiment of this application is shown, wherein... Figure 4 The cross-section shown is perpendicular to the height direction of the battery cell 20, and the Figure 4 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 4 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.

[0110] Figure 5A cross-sectional view of an electrode assembly 220 according to another embodiment of the present application is shown, wherein the Figure 5 The cross-section is perpendicular to the height direction of the battery cell 20, and the Figure 5 The electrode assembly 220 shown can be any one of the electrode assemblies 220 in the electrode assembly set 220 shown in Figures 1 to 3 The electrode assembly 220 shown can be any one of the electrode assemblies 220 in the electrode assembly set 220 shown in Figure 5 The portion of the electrode assembly 220 corresponding to the body portion 221 includes a first pole piece 223 and a plurality of second pole pieces 224, the first pole piece 223 including at least one bent segment 2231 and a plurality of stacked segments 2232, the bent segment 2231 being used to connect two adjacent stacked segments 2232 of the plurality of stacked segments 2232, the plurality of stacked segments 2232 and the plurality of second pole pieces 224 being alternately stacked in a first direction, for example, the thickness direction Y of the battery cell 20, thereby forming a stacked electrode assembly.

[0111] It should be understood that the first pole piece 223 and the second pole piece 224 of the electrode assembly 220 according to the embodiments of the present application are pole pieces of opposite polarity. For example, if the first pole piece 223 is a positive pole piece, the second pole piece 224 is a negative pole piece; conversely, if the first pole piece 223 is a negative pole piece, the second pole piece 224 is a positive pole piece. For example, as shown in Figure 4 and Figure 5 The embodiments of the present application take the first pole piece 223 as a negative pole piece and the second pole piece 224 as a positive pole piece as an example to reduce the risk of metal precipitation of the electrode assembly 220 and improve the electrical performance of the battery cell 20.

[0112] In the embodiments of the present application, the electrode assembly 220 further includes a separator 225 arranged between the positive pole piece and the negative pole piece for separating the positive pole piece and the negative pole piece.

[0113] For the case where the electrode assembly set 22 includes the stacked electrode assembly 220 as shown in Figure 4 and Figure 5 The first insulating film 23 can also be used to fix the electrode assembly set 22 to improve the stability of the electrode assembly set 22. Especially in the case where the electrode assembly set 22 includes a plurality of electrode assemblies 220, the outer circumferential surface 2213 of the electrode assembly set 22 is surrounded by the first insulating film 23, which can increase the structural stability, reduce the misalignment and movement between the plurality of stacked pole pieces, and thus improve the performance of the electrode assembly set 22.

[0114] In some embodiments, for the stacked electrode assembly as shown in Figure 4 and Figure 5 The electrode assembly 220 can further include a fixing structure 2203 to fix the electrode assembly 220. Figure 6and Figure 7 respectively show schematic diagrams of the electrode assembly 220 of embodiments of the present application from different angles, Figure 6 and Figure 7 The electrode assembly 220 shown can be Figure 4 or Figure 5 The electrode assembly 220 shown. Among them, Figure 6 shows a front view schematic diagram of the electrode assembly 220 of embodiments of the present application; Figure 7 shows a bottom view schematic diagram of the electrode assembly 220 of embodiments of the present application.

[0115] As Figure 6 and Figure 7 The electrode assembly 220 includes a first surface 2201 and a second surface 2202 arranged opposite along the thickness direction of the electrode assembly 220, and the electrode assembly 220 further includes a plurality of fixing structures 2203 arranged at intervals, each fixing structure 2203 in 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 first insulating film 23 covers the plurality of fixing structures 2203. For the lamination type electrode assembly, by arranging the plurality of fixing structures 2203, the plurality of electrode sheets of the electrode assembly 220 can be fixed to improve the stability of the electrode assembly 220. Further, the first insulating film 23 of the embodiments of the present application is at least pasted on the outer circumferential surface 2213 of the main body part 221 of the electrode assembly set 22, i.e. pasted on the outside of the plurality of fixing structures 2203 of the main body part 221, which can reduce the movement and misalignment between the plurality of electrode assemblies 220, to further improve the stability of the electrode assembly set 22.

[0116] In some embodiments, different regions of the electrode assembly 220 can be provided with at least one fixing structure 2203. For example, as Figure 6 and Figure 7 The end surface of the electrode assembly 220 for connecting the first surface 2201 and the second surface 2202 is taken as an example. Considering that the fixing structure 2203 is made of insulating material, for the end surface of the electrode assembly 220 provided with the tab 222, no fixing structure 2203 or a small amount of fixing structure 2203 can be arranged to reduce the impact on the tab 222, for example, Figure 6 and Figure 7 The end surface provided with the tab 222 has only one fixing structure 2203 in Figure 6 and Figure 7 The end surface provided with the tab 222 has only one fixing structure 2203 in

[0117] The first insulating film 23 disposed on a portion of the outer surface of the main body 221 according to an embodiment of this application will now be described with reference to the accompanying drawings.

[0118] It should be understood that the first insulating film 23 in this embodiment can be disposed on the surface of the main body 221 in various ways. For example, the first insulating film 23 includes at least one insulating sheet 231, and the first insulating film 23 is folded and wrapped around the outer peripheral surface 2213. Compared with the method of covering the electrode assembly assembly 22 with materials such as heat-shrink film, the first insulating film 23 in this embodiment adopts a sheet structure. At least one insulating sheet 231 can be wrapped and pasted onto the outer peripheral surface 2213 by folding. The processing method is simple and can improve processing efficiency. In addition, the first insulating film 23 can be more tightly attached to the main body 221 of the electrode assembly assembly 22, which can improve the space utilization of the battery cell 20.

[0119] Figure 8 This illustration shows a top view of an electrode assembly 22 encased in a first insulating film 23, according to an embodiment of this application. Figure 8 One possible way to wrap the outer peripheral surface 2213 of the electrode assembly 22 with the first insulating film 23 in the embodiments of this application is to use the first insulating film 23 to wrap the outer peripheral surface 2213 of the electrode assembly 22.

[0120] In some embodiments, such as Figure 8 As shown, the first insulating film 23 may include an insulating sheet 231, which surrounds the outer peripheral surface 2213, such that the starting end and the ending end of the insulating sheet 231 are stacked and fixed to each other on either end face of the outer peripheral surface 2213. For example, Figure 8 The insulating sheet 231 is stacked on its outer peripheral surface 2213 with its starting and ending ends overlapping each other on 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 by the outer peripheral surface 2213. Alternatively, unlike... Figure 8 The starting and ending ends of the insulating sheet 231 may also be stacked on other end faces of the outer peripheral surface 2213, but the embodiments of this application are not limited thereto.

[0121] In some embodiments, such as Figure 8 As shown, taking the example of the starting and ending ends of the insulating sheet 231 overlapping on the side surface 2215 of the outer peripheral surface 2213, when the electrode assembly 22 includes multiple electrode assemblies 220, the overlapping position of the starting and ending ends can be located in any area of ​​the side surface 2215 of the outer peripheral surface 2213, and the size of the overlapping area can also be set according to the actual application. For example, the overlapping area of ​​the starting and ending ends of the insulating sheet 231 can cover the side surface of any one or more electrode assemblies 220 in the electrode assembly 22; or, as... Figure 8As shown, the overlapping regions of the starting end and the ending end of the insulating sheet 231 can cover the middle regions of any two electrode assemblies 220 in the electrode assembly set 22, and the embodiments of the present application are not limited thereto.

[0122] Figures 9 to 11 The top view structural schematic diagrams of the electrode assembly set 22 wrapped with the first insulating film 23 of several other embodiments of the present application are shown respectively, for example, the electrode assembly set 22 wrapped with the first insulating film 23 of the embodiment shown in FIG. 2A. Figures 9 to 11 There are several other possible ways to wrap the outer circumferential surface 2213 of the electrode assembly set 22 with the first insulating film 23 of the embodiments of the present application.

[0123] In some embodiments, the first insulating film 23 can further include a plurality of insulating sheets 231, which are connected to each other to surround the outer circumferential surface 2213. The common surrounding of the outer circumferential surface 2213 by the plurality of insulating sheets 231 can improve the processing flexibility of the battery monomer 20 to adapt to different application scenarios and different types of battery monomers 20.

[0124] It should be understood that, in the case where the first insulating film 23 includes a plurality of insulating sheets 231, the position of each insulating sheet 231 can be set according to actual application.

[0125] For example, as shown in FIG. 2A, the first insulating film 23 includes one insulating sheet 231, which covers the outer circumferential surface 2213 of the electrode assembly set 22. Figures 9 to 11 As shown, the first insulating film 23 includes two insulating sheets 231, which respectively cover the two large faces 2214 of the outer circumferential surface 2213 and overlap and are bonded at the 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 being smaller than the area of the large face 2214 of the outer circumferential surface 2213. The relatively complete insulating sheet 231 is arranged at the two large faces 2214 of the outer circumferential surface 2213, and the overlapping regions of the two insulating sheets 231 are arranged at the two side faces 2215 of the outer circumferential surface 2213, which is simple in processing operation and facilitates improving processing efficiency and structural stability.

[0126] It should be understood that the position and size of the overlapping regions of the two insulating sheets 231 included in the first insulating film 23 at the two side faces 2215 of the outer circumferential surface 2213 can be set according to actual application.

[0127] For example, as shown in FIG. 2A, the first insulating film 23 includes one insulating sheet 231, which covers the outer circumferential surface 2213 of the electrode assembly set 22. Figures 9 to 11 As shown, the electrode assembly set 22 includes a first electrode assembly 2201 and a second electrode assembly 2202, and the insulating sheet 231 bonded to the side face of the outer circumferential surface of the first electrode assembly 2201 is bonded to the side face of the outer circumferential surface of the second electrode assembly 2202 to improve structural stability and reduce the risk of insulation failure of the first insulating film 23.

[0128] Specifically, as shown in FIG. 2A, the first insulating film 23 includes one insulating sheet 231, which covers the outer circumferential surface 2213 of the electrode assembly set 22. Figures 9 to 11As shown, the electrode assembly 22 includes a first electrode assembly 2201 and a second electrode assembly 2202. The first electrode assembly 2201 has one large surface 2214 of its outer peripheral surface 2213, and the second electrode assembly 2202 has another large surface 2214 of its outer peripheral surface 2213. Each side surface 2215 of the outer peripheral surface 2213 includes a side surface of the first electrode assembly 2201 and a side surface of the second electrode assembly 2202. Correspondingly, the first insulating film 23 includes two insulating sheets 231, for example, the two insulating sheets 231 being a first insulating sheet 2311 and a second insulating sheet 2312. The first insulating sheet 2311 is used to adhere to one large surface 2214 of the outer peripheral surface 2213 of the first electrode assembly 2201, and the second insulating sheet 2312 is used to adhere to the other large surface 2214 of the outer peripheral surface 2213 of the second electrode assembly 2202.

[0129] Furthermore, the insulating sheet 231, which is bonded to the side of the outer peripheral surface of the first electrode assembly 2201, is bonded to the side of the outer peripheral surface of the second electrode assembly 2202. That is, the first insulating sheet 2311 is also bonded to the area of ​​the first electrode assembly 2201 and at least a portion of the area of ​​the second electrode assembly 2202 on the side surface 2215 of the outer peripheral surface 2213. That is, on each side surface 2215 of the outer peripheral surface 2213, the first insulating sheet 2311 can extend from the area of ​​the first electrode assembly 2201 to the area of ​​the second electrode assembly 2202.

[0130] like Figure 9 As shown, when the first insulating sheet 2311 covers the area of ​​the first electrode assembly 2201 and at least a portion of the area of ​​the second electrode assembly 2202 on each side 2215 of the outer peripheral surface 2213, the second insulating sheet 2312 may only cover at least a portion of the area of ​​the second electrode assembly 2202 on each side 2215 of the outer peripheral surface 2213, without covering the area of ​​the first electrode assembly 2201 on each side 2215 of the outer peripheral surface 2213, and the second insulating sheet 2312 covers the first insulating sheet 2311 on each side 2215 of the outer peripheral surface 2213.

[0131] like Figure 10 As shown, with Figure 9 The difference is that on each side 2215 of the outer peripheral surface 2213, the first insulating sheet 2311 covers the second insulating sheet 2312.

[0132] like Figure 11As shown, 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 surface 2215 of the outer peripheral surface 2213, 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.

[0133] 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. 2B, 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 9 to 11

[0134] 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 the edge region 22122 of the second end surface 2212 of the embodiment of the application in conjunction with the drawings.

[0135] Figure 12 FIG. 1 shows a schematic diagram of the internal structure of the battery monomer 20 of the embodiment of the application, for example, the battery monomer 20 shown in FIG. 1 can be a cylindrical battery monomer. Figure 12 FIG. 2A shows a schematic diagram of the internal structure of the battery monomer 20 shown in FIG. 1. Figure 1 FIG. 2B shows a schematic diagram of the internal structure of the battery monomer 20 shown in FIG. 1. Figure 2 FIG. 2C shows a possible implementation manner of the battery monomer 20 shown in FIG. 1. Figure 13 FIG. 3 shows a schematic diagram of the cross section of the battery monomer 20 of the embodiment of the application, for example, the battery monomer 20 shown in FIG. 3 can be a cylindrical battery monomer. Figure 13 FIG. 4A shows a schematic diagram of the cross section of the battery monomer 20 shown in FIG. 3. Figure 12 FIG. 4B shows a cross-sectional view of the battery monomer 20 shown in FIG. 3, that is, Figure 13 FIG. 4C shows a possible implementation manner of the battery monomer 20 shown in FIG. 3. Figure 1 FIG. 4D shows a possible implementation manner of the battery monomer 20 shown in FIG. 3. Figure 2 FIG. 4E shows a cross section of the battery monomer 20 shown in FIG. 3, that is, Figure 13 FIG. 4F shows a cross section of the battery monomer 20 shown in FIG. 3, that is, Figure 13 FIG. 4G shows a cross section of the battery monomer 20 shown in FIG. 3, that is, Figure 12 FIG. 4H shows a schematic diagram of the cross section of the battery monomer 20 shown in FIG. 3 in the A-A’ direction. Figure 14 FIG. 5 shows another angle of the partial cross-sectional schematic diagram of the battery monomer 20 of the embodiment of the application, for example, Figure 14 FIG. 5A shows a partial enlarged view of the region close to the lower partition 24 in FIG. 5. Figure 13 FIG. 5B shows a partial enlarged view of the region close to the lower partition 24 in FIG. 5.

[0136] ​In some embodiments, 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 covers the entire region of the outer circumferential surface 2213, and the second portion 234 is bent relative to the first portion 233 and covers the edge region 22122 of the second end surface 2212. As shown in Figures 12 to 14 the first portion 233 and the second portion 234 of the first insulating film 23 are relatively bent, when the first insulating film 23 is pasted, the first insulating film 23 can be wrapped around the outer circumferential surface 2213, so that the first portion 233 of the first insulating film 23 covers the entire region of the outer circumferential surface 2213 to isolate the outer circumferential surface 2213 of the main body portion 221 and the shell 21, and the portion exceeding the outer circumferential 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 region 22122 of the second end surface 2212, and the second portion 234 and the partition 24 together isolate the second end surface 2212 and the shell 21, the processing process is simple and easy to implement.

[0137] Figure 15 A schematic view of the second end surface 2212 of the main body portion 221 to which the first insulating film 23 is pasted is shown. In some embodiments, as shown in Figure 15 the second end surface 2212 includes a middle region 22121 and an edge region 22122 surrounding the middle region 22121, the first insulating film 23 covers the edge region 22122 of the second end surface 2212 and does not cover the middle region 22121 of the second end surface 2212, that is, the middle region 22121 of the second end surface 2212 is a region of the second end surface 2212 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 covered by the first insulating film 23. The first insulating film 23 only covers a partial region of the second end surface 2212, which can isolate the second end surface 2212 and the shell 21 through the partition 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 cell 20.

[0138] 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.

[0139] As Figures 12 to 15As shown, 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.

[0140] It should be understood that the relative position relationship between the main body part 221 and the shell 21 of the embodiments of the present application can be set according to actual application, and the following will be described by taking the shell 21 as an example. Figures 12 to 15

[0141] In the embodiments of the present application, the shell 21 comprises a shell body 211 having an opening 2111, and a cover plate 212 for covering the opening 2111 to form a containing cavity. Specifically, the shell body 211 is a hollow structure having an opening 2111, and the electrode assembly set 22 wrapped with the first insulating film 23 is contained in the shell body 211 through the opening 2111; the cover plate 212 is used to cover the opening 2111 of the shell body 211 to isolate the external environment.

[0142] In some embodiments, the shell body 211 can be a hollow structure having an opening 2111 formed at least at one end, and the shape of the cover plate 212 can be adapted to the shape of the shell body 211, and the cover plate 212 is used to cover the opening 2111 of the shell body 211, so that the shell 21 isolates the internal environment of the battery monomer 20 from the external environment. If the shell body 211 is a hollow structure having an opening 2111 formed at one end, the cover plate 212 can be provided as one; or if the shell body 211 is a hollow structure having an opening 2111 formed at opposite ends, the cover plate 212 can be provided as two, and the two cover plates 212 cover the openings 2111 at the two ends of the shell body 211 respectively, and the embodiments of the present application are not limited thereto.

[0143] The material of the shell body 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 shell body 211.

[0144] ​The shell 211 and the cover plate 212 of the embodiment of the present application are in matching shapes, for example, the shell 211 can be in a cuboid structure, and the cover plate 212 is in a rectangular plate structure matching the shell 211. The cover plate 212 can be any wall of the shell 21, for example, the cover plate 212 can be the wall with the largest area among the walls included in the shell 21, or the wall with the smallest area, or can be other walls, and the embodiment of the present application is 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 with an opening to cover the opening 2111 of the shell 211, and the embodiment of the present application is not limited thereto.

[0145] For ease of illustration, the shell 211 is mainly taken as an example of a hollow structure with an opening at one end; correspondingly, the opening 2111 of the shell 211 is covered by the cover plate 212, for example, the sealing connection between the shell 211 and the cover plate 212 can be achieved by welding to form a closed cavity for placing the electrode assembly set 22, thereby improving the sealing reliability.

[0146] It should be understood that the relative position relationship between each end face of the main body part 221 and the shell 21 can be flexibly set according to actual application. For example, the first end face 2211 provided with the tab 222 can face any wall of the shell 21.

[0147] In some embodiments, the first end face 2211 faces the cover plate 212, and the second end face 2212 faces the bottom wall 2112 of the shell 211, so as to facilitate installation. The bottom wall 2112 of the shell 211 is opposite to the opening 2111. For example, during installation, the electrode assembly set 22 with the first insulating film 23 and the separator 24 pasted thereon can be placed into the shell 211 from the opening 2111 of the shell 211, and the second end face 2212 of the electrode assembly set 22 faces the bottom wall 2112 of the shell 211, the first end face 2211 provided with the tab 222 faces the opening 2111, and then the cover plate 212 covers the opening 2111.

[0148] In some embodiments, the shell 21 of the battery monomer 20 of the embodiment of the present application can also be provided with an electrode terminal 214, and the electrode terminal 214 is used to be electrically connected with the electrode assembly set 22 to output the electric energy of the battery monomer 20. As shown in FIG. 2, the electrode terminal 214 can be provided on the bottom wall 2112 of the shell 211, and the electrode terminal 214 can be electrically connected with the electrode assembly set 22 through the bottom wall 2112 of the shell 211. Figures 12 to 15As 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. For example, the positive tab 222a of the electrode assembly 22 can be connected to the positive electrode terminal 214a via a current collector, and the negative tab 222b of the electrode assembly 22 can be connected to the negative electrode terminal 214b via another current collector.

[0149] 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 12 to 15 As shown, the embodiments of this application mainly take the battery cell 20 as having two electrode terminals 214, and the two electrode terminals 214 being disposed on the cover plate 212 of the battery cell 20, in order to facilitate processing.

[0150] Furthermore, the battery cell 20 also includes an insulating member 25, which is fixed to the cover plate 212 and located between the cover plate 212 and the first end face 2211, so that the insulating member 25 can be used to isolate the first end face 2211 from the cover plate 212. In some embodiments, a 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, thereby further improving the stability of the various components inside the battery cell 20.

[0151] like Figures 12 to 15 As shown, along a direction perpendicular to the first end face 2211, the edge of the first portion 233 facing the cover plate 212 extends beyond the first end face 2211, so that the first portion 233 is bonded and fixed to the insulating member 25. For example, taking the direction perpendicular to the first end face 2211 as the height direction Z of the battery cell 20, in this height direction Z, the upper edge of the first portion 233 extends beyond the first end face 2211 and can extend to the insulating member 25, so that the edge of the first portion 233 can be bonded and fixed to the insulating member 25, which can further improve the insulation performance and the structural stability of the battery cell 20. Furthermore, since the first insulating film 23 has an adhesive, no additional fixing method such as heat fusion is required between the first insulating film 23 and the insulating member 25, which can improve processing efficiency.

[0152] It should be understood that the size of the first insulating film 23 in the embodiments of the present application can be set according to actual application. For example, the thickness of the first insulating film 23 is in the range of [35um, 80um]. The thickness of the first insulating film 23 is greater than or equal to 35um, so that the first insulating film 23 is not easy to break, the reliability of the first insulating film 23 can be improved, and the insulation performance of the first insulating film 23 can be improved. At the same time, the thickness of the first insulating film 23 is less than or equal to 80um, so that the space occupied by the first insulating film 23 can be reduced, and the energy density of the battery monomer 20 can be improved.

[0153] 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.

[0154] 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.

[0155] It should be understood that the material of the first insulating film 23 in the embodiments of the present application can be any insulating material to be suitable for 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 a glue layer. Compared with the original mylar film wrapped around the electrode assembly set 22, the thickness of the blue film is thinner, and the structural strength and insulation performance thereof can also meet the design requirements. The thinner blue film can reduce the occupied space and improve the energy density of the battery monomer 20.

[0156] In some embodiments, the material of the blue film mainly includes polyethylene terephthalate (PET), so that the blue film is suitable for battery monomers 20 of different chemical systems, is easy to process and easy to implement.

[0157] The spacer 24 in the embodiments of the present application will be described below with reference to the accompanying drawings.

[0158] It should be understood that the spacer 24 in the embodiments of the present application can also be used to pad the electrode assembly set 22 to reduce the influence of the round corner of the shell 21 on the internal electrode assembly set 22.

[0159] In some embodiments, the shell 21 comprises a first wall 201 and a second wall 202 intersecting each other, and the first wall 201 and the second wall 202 are connected by a rounded corner 203, the second end surface 2212 faces the second wall 202, and the thickness T of the partition 24 is greater than or equal to the radius R of the rounded corner 203, so as to elevate the electrode assembly set 22 and reduce the interference of the edge portion of the electrode assembly set 22 in the rounded corner 203.

[0160] As shown in Figure 14 , taking the first wall 201 as an example, any one side wall of the shell 211, and the second wall 202 is the bottom wall 2112 of the shell 211, and the partition 24 is arranged towards the bottom wall 2112 of the shell 211. In the case that the thickness T of the partition 24 is greater than or equal to the radius R of the rounded corner 203, the electrode assembly set 22 is arranged above the partition 24, and the approximately right-angled corner region of the electrode assembly set 22 is beyond the region of the rounded corner 203, for example, the corner region can be the intersection line of the second end surface 2212 and the outer peripheral surface 2213 of the main body 221, so as to reduce the influence of the rounded corner 203 on the electrode assembly set 22 and improve the use performance of the electrode assembly set 22.

[0161] In some embodiments, the thickness T of the partition 24 can be set according to actual application. For example, the size of the thickness T of the partition 24 is related to the size of the radius R of the rounded corner 203.

[0162] In some embodiments, the thickness T of the partition 24 can be set according to actual application. For example, the size of the thickness T of the partition 24 is related to the size of the radius R of the rounded corner 203.

[0163] Further, the thickness T of the partition 24 can also be [0.3mm, 0.5mm], so as to balance the structural strength of the partition 24 and the energy density of the battery monomer 20.

[0164] In some embodiments, the thickness T of the separator 24 may also be other values. For example, the thickness T of the separator 24 may also be any 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.

[0165] Figure 16 A schematic diagram of the internal structure of a battery cell 20 according to another embodiment of this application is shown. For example, the... Figure 16 The battery cell 20 shown can be Figure 1 and Figure 2 Another possible implementation of the battery cell 20 shown. Figure 17 A top view of the separator 24 according to an embodiment of this application is shown, for example, Figure 17 This can be a schematic diagram of the surface of the separator 24 facing the second end face 2212. Figure 18 A bottom view schematic diagram of an electrode assembly 22 with a spacer 24 and a first insulating film 23 attached, according to an embodiment of this application, is shown. Figure 18 This can be a schematic diagram of the second end face 2212 with the separator 24 and the first insulating film 23 pasted on.

[0166] 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.

[0167] like Figures 16 to 18 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.

[0168] 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.

[0169] 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 12 to 15 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.

[0170] For example, unlike Figures 12 to 15 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.

[0171] In some embodiments, such as Figures 16 to 18 As shown, the edge region 242 of the separator 24 includes a curved portion 2421, which includes a protruding structure 24211 protruding toward the second end face 2212 and a recessed structure 24212 protruding away from the second end face 2212. The edge region 242 of the separator 24 is the portion of the separator 24 excluding the middle region 241, and it surrounds the middle region 241 of the separator 24.

[0172] The surface of the middle region 241 of the separator 24 facing the second end face 2212 is flat, which can improve the structural stability between the separator 24 and the electrode assembly 22. A curved portion 2421 is provided in the edge region 242 of the separator 24, so that there is more gap between the separator 24 and the second end face 2212. This facilitates the flow of electrolyte from the uneven gaps of the curved portion 2421 into the area of ​​the second end face 2212, improving the wetting performance of the electrode assembly 22 and enhancing the electrical performance of the battery cell 20.

[0173] That is, the edge region 242 of the separator 24 is at least partially set to a wavy shape.

[0174] It should be understood that the number, size, and position of the curved portions 2421 included in the edge region 242 of the separator 24 in the embodiments of this application can be set according to the actual application.

[0175] In some embodiments, the edge region 242 of the separator 24 includes two curved portions 2421 disposed opposite each other 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 second end face 2212 in the width direction is smaller than its size in the length direction. For example, as... Figures 16 to 18 As shown, taking the width direction of the second end face 2212 as the width direction Y of the battery cell 20 as an example, the edge region 242 of the separator 24 includes two oppositely arranged curved portions 2421. Each curved portion 2421 extends along the length direction of the second end face 2212, that is, along the length direction X of the battery cell 20. Therefore, the length of each curved portion 2421 is relatively large, which makes the separator 24 and the second end face 2212 have more gaps, which is more conducive to electrolyte wetting; and the two curved portions 2421 are symmetrically distributed, which can improve structural stability.

[0176] In some embodiments, the portion of the edge region 242 of the separator 24 other than the curved portion 2421 is a flat portion 2422, and the surface of the flat portion 2422 facing the second end face 2212 is flat. For example... Figures 16 to 18 As shown, the stability and insulation between the separator 24 and the electrode assembly 22 can be further increased by the provided planar portion 2422.

[0177] Alternatively, the edge region 242 of the separator 24 may not have a flat portion 2422. For example, the entire edge region 242 of the separator 24 may be a curved portion 2421 to improve the efficiency of electrolyte wetting of the electrode assembly 22.

[0178] In some embodiments, the surface of the bent portion 2421 facing the second end face 2212 may also be provided with an adhesive, so that the protruding structure 24211 of the bent portion 2421 facing the second end face 2212 can be bonded to the second end face 2212, thereby further improving the stability and insulation between the separator 24 and the electrode assembly 22.

[0179] It should be understood that in this embodiment, both the separator 24 and the first insulating film 23 can be adhered to the second end face 2212 using an adhesive. The materials of the adhesive for the separator 24 and the adhesive for the first insulating film 23 can be set according to the actual application. For example, the adhesive for the separator 24 and the adhesive for the first insulating film 23 can be selected according to the material of the electrolyte inside the battery cell 20 to reduce the impact of the electrolyte on the stability of the adhesive adhesion. Furthermore, the materials of the adhesive for the separator 24 and the adhesive for the first insulating film 23 can be the same or different; this embodiment is not limited to this.

[0180] In some embodiments, along the length direction of the second end surface 2212, the length L1 of the curved portion 2421 is greater than the length L2 of the middle region 22121 of the second end surface 2212. As shown in Figures 16 to 18 For example, taking the length direction of the second end surface 2212 as the length direction X of the battery cell, 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 surface 2212, so as to increase the gap between the separator 24 and the second end surface 2212, thereby improving the infiltration efficiency.

[0181] In some embodiments, along the width direction of the second end surface 2212, the curved portion 2421 covers at least part of the edge region 22122 of the second end surface 2212 and part of the middle region 22121 of the second end surface 2212. As shown in Figures 16 to 18 For example, taking the length direction of the second end surface 2212 as the length direction X of the battery cell, the curved portion 2421 can cover the region at the boundary between the edge region 22122 of the second end surface 2212 and the middle region 22121 of the second end surface 2212, i.e., the edge of the middle region 241 of the separator 24 facing the curved portion 2421 exceeds the edge of the edge region 22122 of the second end surface 2212 facing 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 which is not covered by the first insulating film 23 through the curved portion 2421, thereby improving the infiltration efficiency of the electrode assembly set 22 and the performance of the battery cell 20.

[0182] It should be understood that the above-mentioned middle region 22121 of the second end surface 2212 is the region of the second end surface 2212 which 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 which is covered by the first insulating film 23, and the edge region 22122 of the second end surface 2212 surrounds the middle region 22121 of the second end surface 2212.

[0183] Figure 19 An exploded schematic view of another partial structure of the battery cell 20 according to an embodiment of the present application is shown in FIG. 6. Figure 19 The battery cell 20 shown in FIG. 6 can be another possible implementation of the battery cell 20 according to an embodiment of the present application. Figure 20 An internal structure schematic view of the battery cell 20 according to an embodiment of the present application is shown in FIG. 7. Figure 20 The battery cell 20 shown in FIG. 7 can be Figure 19 The battery cell 20 shown in FIG. 7. Figure 21 A cross-sectional schematic view of the battery cell 20 according to an embodiment of the present application is shown in FIG. 8. Figure 21 The battery cell 20 shown in FIG. 8 can be Figure 20A cross-sectional view of the battery cell 20 is shown, and Figure 21 The cross-section is perpendicular to the length direction X of the battery cell 20, that is, Figure 21 A cross-sectional view of the battery cell 20 along the B-B' direction is shown. Figure 20 A cross-sectional view of the battery cell 20 along the B-B' direction is shown. Figure 22 Another partial cross-sectional view of the battery cell 20 according to an embodiment of the present application is shown, for example, Figure 22 The battery cell 20 shown can be Figure 20 A cross-sectional view of the battery cell 20 is shown, and Figure 22 The cross-section is perpendicular to the length direction X of the battery cell 20, and Figure 22 The cross-section passes through the electrode terminal 214.

[0184] In the embodiment of the present application, as shown, Figures 19 to 22 The battery cell 20 further includes a current collecting member 27 connecting the tab 222 and the electrode terminal 214, and a second insulating film 26 including a body portion 261 and an extension portion 262, the body portion 261 being arranged between the current collecting member 27 and the insulating member 25 to isolate the current collecting member 27 and the insulating member 25, and the extension portion 262 covering at least part of the large face 2214 of the outer peripheral surface 2213, the first insulating film 23 wrapping and fixing the extension portion 262, and the large face 2214 of the outer peripheral surface 2213 being the face with the largest area.

[0185] It should be understood that the current collecting member 27 of the embodiment of the present 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 electrode tab 222a and the positive electrode terminal 214a can be located between the positive electrode tab 222a and the positive electrode terminal 214a, and the current collecting member 27 used to electrically connect the negative electrode tab 222b and the negative electrode terminal 214b can be located between the negative electrode tab 222b and the negative electrode terminal 214b, so as to facilitate the processing and assembly of the battery cell 20.

[0186] The second insulating film 26 of the embodiment of the present application includes the relatively bent body portion 261 and the extension portion 262. The body portion 261 is arranged between the current collecting member 27 and the cover plate 212, for example, and can be specifically 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 current collecting member 27 and the cover plate 212, and can also be used to isolate the first end face 2211 where the tab 222 is located and the cover plate 212, 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, that is, 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.

[0187] The extension 262 of the second insulating film 26 of the embodiment of the present application covers part of the outer circumferential surface 2213, and the first insulating film 23 wraps and fixes the extension 262. The fixing of the second insulating film 26 is simultaneously achieved through the fixing between the first insulating film 23 and the electrode assembly set 22, which facilitates processing and improves structural stability.

[0188] In some embodiments, as shown in Figures 19 to 22 the extension 262 covers at least part of the large surface 2214 of the outer circumferential surface 2213, and the first insulating film 23 wraps and fixes the extension 262. The large surface 2214 of the outer circumferential surface 2213 is the surface with the largest area of the outer circumferential surface 2213. The extension 262 is used to cover the large surface 2214 of the outer circumferential surface 2213, which can increase the contact area between the extension 262 and the outer circumferential surface 2213 of the main body part 221, facilitate the covering and fixing of the second insulating film 26 by the first insulating film 23, further improve the structural stability, and reduce the risk of insulation failure of the battery monomer 20.

[0189] In some embodiments, as shown in Figures 19 to 22 the second insulating film 26 includes two extensions 262 arranged opposite to each other, and the two extensions 262 respectively cover at least part of the two large surfaces 2214 of the outer circumferential surface 2213. The second insulating film 26 is arranged to have two opposite extensions 262, so that the second insulating film 26 has a relatively symmetrical structure, which can improve the stability of the second insulating film 26.

[0190] Figure 23 The structure of the second insulating film 26 of the embodiment of the present application is shown, for example, Figure 23 which can be a top view of the second insulating film 26 of the embodiment of the present application in an unfolded state. As shown in Figure 23 the second insulating film 26 can adopt a sheet structure and be provided with two creases 263 arranged in parallel. The second insulating film 26 is folded along the two creases 263, so that the body part 261 and the two extensions 262 arranged opposite to each other are obtained. The body part 261 is arranged between the cover plate 212 and the current collecting member 27. The second insulating film 26 is folded through the two pre-set creases 263, so that the two extensions 262 are covered on the two large surfaces 2214 of the outer circumferential surface 2213. The operation is simple and convenient to implement.

[0191] In some embodiments, as shown in Figures 19 to 23 the insulating part 25 includes 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 to realize the electrical connection between the electrode terminal 214 and the tab 222, and then output electric energy.

[0192] In some embodiments, as shown in Figures 19 to 23As shown, the cover plate 212 includes a third electrode lead-out hole 2011, and the electrode terminal 214 passes through the third electrode lead-out hole 2011 to be connected with the current collecting member 27. For example, the electrode terminal 214 can pass through the third electrode lead-out hole 2011 and the first electrode lead-out hole 251 in sequence to be connected with the current collecting member 27, so as to realize the electrical connection between the electrode terminal 214 and the tab 222, and then output the electric energy.

[0193] In some embodiments, as shown in FIG. 2B, the body part 261 includes 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 with the current collecting member 27. For example, the electrode terminal 214 can pass through the third electrode lead-out hole 2011, the first electrode lead-out hole 251 and the second electrode lead-out hole 2611 in sequence to be connected with the current collecting member 27; or the electrode terminal 214 can pass through the third electrode lead-out hole 2011 and the first electrode lead-out hole 251 in sequence, and the current collecting member 27 passes through the second electrode lead-out hole 2611 to be connected with the electrode terminal 214, so as to realize the electrical connection between the electrode terminal 214 and the tab 222, and then output the electric energy. Figures 19 to 23

[0194] FIG. 2B shows a structure schematic diagram of the current collecting member 27, the second insulating film 26 and the insulating piece 25 in the battery cell 20 of the embodiments of the present application. For example, FIG. 2B can be a bottom view schematic diagram of the current collecting member 27, the second insulating film 26 and the insulating piece 25. Figure 24 Figure 24 Figures 19 to 23

[0195] In some embodiments, as shown in FIG. 2B, the current collecting member 27 includes an electrode terminal connecting part 271 for electrical connection with the electrode terminal 214. For example, the electrode terminal 214 passes through the second electrode lead-out hole 2611 to be connected with the electrode terminal connecting part 271. For another example, the electrode terminal 214 passes through the third electrode lead-out hole 2011, the first electrode lead-out hole 251 and the second electrode lead-out hole 2611 in sequence to be connected with the electrode terminal connecting part 271. Figures 19 to 24 In some embodiments, unlike the above, the electrode terminal 214 can pass through the third electrode lead-out hole 2011 and the first electrode lead-out hole 251 in sequence, and the electrode terminal connecting part 271 passes through the second electrode lead-out hole 2611. For example, the electrode terminal connecting part 271 can protrude towards the electrode terminal 214 through the second electrode lead-out hole 2611, so as to realize the electrical connection between the electrode terminal 214 and the electrode terminal connecting part 271 of the current collecting member 27.

[0196] Figures 19 to 24

[0197] ​​​​​In some embodiments, the electrode terminal 214 can sequentially pass through the third electrode lead-out hole 2011 and the first electrode lead-out hole 251, and a partial region of the electrode terminal 214 is accommodated in the second electrode lead-out hole 2611, and the electrode terminal connecting portion 271 is also accommodated in the second electrode lead-out hole 2611, so that the electrode terminal 214 and the electrode terminal connecting portion 271 of the current collecting member 27 are connected in the second electrode lead-out hole 2611, thereby realizing the electrical connection between the electrode terminal 214 and the current collecting member 27.

[0198] 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, and 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. Figures 19 to 24

[0199] In some embodiments, the battery cell 20 further includes a pressure relief mechanism 213 arranged on the cover plate 212, and the body portion 261 further includes a pressure relief hole 2612 arranged corresponding to the pressure relief mechanism 213. In this way, when the battery cell 20 is in thermal runaway, by arranging the pressure relief hole 2612, the second insulating film 26 can reduce the obstruction to the discharge of the battery cell 20, so that the pressure relief mechanism 213 can be actuated in time to quickly discharge the discharge material, thereby improving the reliability of the battery cell 20.

[0200] 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 value, so as to release the internal pressure or temperature. When the internal pressure or temperature of the battery cell 20 reaches the predetermined threshold value, 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 releasing the internal pressure or temperature. The threshold value is designed to be different 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.

[0201] As an example, the pressure relief mechanism 213 can be integrally formed with the cover plate 212; alternatively, the pressure relief mechanism 213 can be separately arranged and connected with the cover plate 212.

[0202] ​As used herein, "actuation" of the pressure relief mechanism 213 refers to the pressure relief mechanism 213 being activated or moved to a state in which the internal pressure and temperature of the battery cell 20 can be released. The movement of the pressure relief mechanism 213 can include, but is not limited to, movement of components in the pressure relief mechanism 213 to form a venting path, at least a portion of the pressure relief mechanism 213 rupturing, breaking, tearing, or opening, and the like. Upon actuation of the pressure relief mechanism 213, the high temperature and pressure material inside the battery cell 20 can be released as discharge material from the actuated portion. In this way, the battery cell 20 can be pressure and temperature released in a controlled manner to avoid potentially more severe accidents.

[0203] As used herein, the discharge material from the battery cell 20 can include, but is not limited to, electrolyte, dissolved or broken positive and negative electrode sheets, fragments of separators, high temperature and pressure gases generated by reactions, flames, and the like.

[0204] It should be understood that the size and shape of the pressure relief hole 2612 can be configured 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 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 generally less than or equal to the area of the pressure relief hole 2612, i.e., the projection of the pressure relief mechanism 213 toward the body portion 261 is generally 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 discharge material when the battery cell 20 experiences thermal runaway, thereby improving the reliability of the battery cell 20.

[0205] In some embodiments, the battery cell 20 further includes a liquid injection structure 215 disposed on the cover plate 212, and the body portion 261 further includes a liquid injection hole 2613 corresponding to the liquid injection structure 215. The liquid injection hole 2613 is configured to allow the electrolyte to easily infiltrate the electrode assembly set 22, thereby facilitating the processing efficiency of the battery cell 20.

[0206] It should be understood that the liquid injection structure 215 of the embodiments of the present application can include a liquid injection through hole disposed on the cover plate 212 and a sealing structure for sealing the liquid injection through hole. The electrolyte is injected into the battery cell 20 through the liquid injection through hole disposed on the cover plate 212 and the liquid injection hole 2613 of the body portion 261, and the liquid injection through hole of the cover plate 212 is sealed by the sealing structure to reduce the risk of electrolyte leakage and improve the reliability and stability of the battery cell 20.

[0207] It should be understood that the size of the extension portion 262 of the embodiments of the present application can be configured according to actual application. For example, as shown in FIG. 2A, the extension portion 262 can be configured to extend from the body portion 261 to the cover plate 212, and the extension portion 262 can be configured to extend from the body portion 261 to the cover plate 212. Figures 19 to 24As 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.

[0208] Figure 25 Another partial cross-sectional view of the battery cell 20 according to an embodiment of the present application is shown, for example, Figure 25 The battery cell 20 shown can be Figure 19 and Figure 20 Another possible partial cross-sectional view of the battery cell 20 is shown, and Figure 25 The cross-section shown is perpendicular to the length direction X of the battery cell 20, and Figure 25 The cross-section shown passes through the electrode terminal 214.

[0209] In some embodiments, as Figure 25 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 cover plate 212, thereby improving the insulation reliability between the tab connecting portion 272 and the cover plate 212.

[0210] In some embodiments, the first region 281 can also be used to paste and cover the surface of the tab 222 facing the cover plate 212 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 cover plate 212, further improving the internal insulation reliability of the battery monomer 20.

[0211] 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 cover plate 212, further improving the internal insulation reliability of the battery monomer 20.

[0212] In some embodiments, the first region 281 of the third insulating film 28 is located between the first end surface 2211 and the body part 261 of the second insulating film 26, by bending the third insulating film 28, so that the second region 282 of the third insulating film 28 is pasted and covers part of the outer peripheral surface 2213, which can improve the stability and reliability of the third insulating film 28, and in turn reduce the risk of insulation failure between the tab 222 and the cover plate 212.

[0213] 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 cover plate 212, so that the second insulating film 26 further fixes the third insulating film 28, to improve the stability and reliability of the third insulating film 28. Figure 25 As shown, taking the thickness direction of the cover plate 212 as the height direction Z of the battery monomer 20, 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, so that the end of the extension part 262 away from the cover plate 212 exceeds the end of the second region 282 away from the cover plate 212, so that the extension part 262 can cover the entire region of the second region 282, further fixing the second region 282.

[0214] In some embodiments, the melting point of the third insulating film 28 is greater than the melting point of the second insulating 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 insulating film 28 is less likely to be damaged than the second insulating film 26, which can improve the insulation reliability between the tab 222 and the cover plate 212, and reduce the risk of insulation failure.

[0215] 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 insulating film 28 refers to the temperature at which the third insulating film 28 is damaged or melted.

[0216] It should be understood that the material of the third insulating film 28 can be set according to actual application. For example, the material of the third insulating film 28 can include polyimide (PI) so that the third insulating film 28 can be resistant to high temperature and easy to implement.

[0217] 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 solutions.

[0218] The battery apparatus mentioned in the embodiments of the present application can comprise one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly can comprise a plurality of battery cells connected in series, in parallel or in a mixed connection through a busbar component.

[0219] In some embodiments, the battery cell assembly is generally formed by arranging a plurality of battery cells.

[0220] 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.

[0221] In some embodiments, the battery apparatus can be a battery pack comprising a box and one or more battery cell assemblies accommodated in the box.

[0222] As an example, the battery cell assembly can be a battery module, which can be accommodated in the box by fixing the battery module in the box.

[0223] As an example, the battery cell assembly can also be accommodated in the box by directly fixing a plurality of battery cells in the box.

[0224] As an example, the box can comprise a first box and a second box. The first box and the second box are buckled so that a closed space is formed inside the box to accommodate the battery cell assembly. Here, closed means covered or closed, which can be sealed or unsealed. The first box can be a top cover or a bottom plate.

[0225] As an example, the box can comprise a top cover, a frame and a bottom plate. The top cover and the bottom plate are connected with the frame respectively, so that a closed space is formed inside the box to accommodate the battery cell assembly.

[0226] In some embodiments, the battery case can be part of a chassis structure of a vehicle. For example, portions of the battery case can be part of a floor of the vehicle, or portions of the battery case can be part of cross members and longitudinal members of the vehicle.

[0227] According to some embodiments of the present application, the present application also provides a power consuming device comprising the battery of any of the above-mentioned embodiments, and the battery is configured to provide power to the power consuming device.

[0228] The power consuming device can be any device or system that uses a battery. For example, the power consuming device can be a mobile phone, a portable device, a notebook computer, an electric vehicle, an electric toy, an electric tool, a vehicle, a ship, a spacecraft, etc. For example, the spacecraft can include an airplane, a rocket, a space shuttle, a spacecraft, etc.

[0229] Embodiments of the present application provide a power storage device comprising one or more battery clusters to improve the voltage and capacity of the power storage device. The battery cluster can comprise a plurality of battery devices, and the plurality of battery devices are connected in series by a busbar to improve the voltage of the power storage device. When the power storage device comprises a plurality of battery clusters, the plurality of battery clusters are connected in parallel to improve the capacity of the power storage device.

[0230] The power storage device can be used in a power storage plant, a wind power system, a solar power system, a mobile power system, or a temporary power supply system, etc. The power storage device can store power as needed and output power at an appropriate time. For example, the power storage device can store power during a low power consumption period, and provide power to relevant users or power consuming devices during a high power consumption period. The power storage system provided by embodiments of the present application can be any power system that needs to use a power storage device.

[0231] In some embodiments, the power storage device is a power storage container or a power storage cabinet.

[0232] In some embodiments, the power storage device can comprise a cabinet and one or more battery clusters, and the battery clusters are accommodated in the cabinet.

[0233] In some embodiments, the power storage device can comprise a thermal management module, a master control module, a general control module, a power distribution module, a fire control module, etc.

[0234] As an example, the thermal management module can comprise a liquid cooling unit, and the liquid cooling unit provides a cooling liquid for adjusting the temperature of the battery cells to each battery device through a pipeline.

[0235] As an example, the master module can be used as a battery management unit of the battery cluster, for monitoring and managing the battery cluster. The master module can monitor information such as current, voltage, power or temperature of the battery cluster. For example, the charging and discharging current, voltage, etc. of the battery cluster can be controlled. The master module includes a slave battery management unit (SBMU), a fuse module, etc.

[0236] As an example, the master module can be used as a battery management unit of the battery cluster, for monitoring and managing the battery cluster. The master module can monitor information such as current, voltage, power or temperature of the battery cluster. For example, the charging and discharging current, voltage, etc. of the battery cluster can be controlled. The master module includes a slave battery management unit (SBMU), a fuse module, etc.

[0237] As an example, the fire-fighting system includes a control panel, a detector, an alarm device, etc., for detecting, alarming or extinguishing the energy storage system.

[0238] As an example, the power distribution device can be used to distribute power to the energy storage device power module.

[0239] According to some embodiments of the present application, the present application also provides an energy storage system including the energy storage device of any 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), and the power conversion device is used to connect 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, etc. The specific type of the power generation device is not limited in the present application.

[0240] According to some embodiments of the present application, the present application provides a charging network. The charging network includes a charging pile and an energy storage device, and the charging pile is electrically connected with the energy storage device, and the energy storage device is used to provide electric energy for the charging pile. The charging pile and the battery device in the energy storage device are electrically connected through a cable, and the battery device can provide the electric energy stored by itself to the charging pile. The charging pile has one or more connectors, and the connector is used to connect with an electric device (such as a vehicle), so as to charge the electric device.

[0241] The energy storage device can be located inside the charging pile (for example, a charging and storage integrated machine) or outside the charging pile.

[0242] According to some embodiments of the present application, referring to Figures 8 to 18 The battery cell 20 includes a housing 21, a set of electrode assemblies 22, a first insulating film 23, and a separator 24. The housing 21 has a receiving cavity, and the set of electrode assemblies 22 is arranged in the receiving cavity. The set of electrode assemblies 22 includes at least one electrode assembly 220, which includes a main body part 221 and a tab 222. The main body part 221 includes a first end face 2211, a second end face 2212 opposite to the first end face 2211, and an outer peripheral surface 2213 connecting the first end face 2211 and the second end face 2212. The tab 222 is located at the first end face 2211. The first insulating film 23 is attached to and covers the outer peripheral surface 2213 and an edge region 22122 of the second end face 2212. The separator 24 is attached to and covers a region of the second end face 2212 that is not covered by the first insulating film 23, and the separator 24 covers the first insulating film 23.

[0243] The electrode assembly 220 has a laminated structure. The electrode assembly 220 includes a first face 2201 and a second face 2202 arranged opposite to each other in a thickness direction of the electrode assembly 220. The electrode assembly 220 further includes a plurality of fixing structures 2203 arranged at intervals. Each of the fixing structures 2203 extends from an edge of the first face 2201 to an edge of the second face 2202 in the thickness direction of the electrode assembly 220. The first insulating film 23 covers the plurality of fixing structures 2203.

[0244] The first insulating film 23 includes at least one insulating sheet 231, and the first insulating film 23 is folded and wrapped around the outer peripheral surface 2213. The first insulating film 23 includes two insulating sheets 231, which respectively cover two large faces 2214 of the outer peripheral surface 2213 and overlap and are bonded at two side faces 2215 of the outer peripheral surface 2213 to cover the outer peripheral surface 2213. The area of the side face 2215 of the outer peripheral surface 2213 is smaller than the area of the large face 2214 of the outer peripheral surface 2213. The set of electrode assemblies 22 includes a first electrode assembly 2201 and a second electrode assembly 2202. The insulating sheet 231 bonded to the side face of the outer peripheral surface of the first electrode assembly 2201 is bonded to the side face of the outer peripheral surface of the second electrode assembly 2202.

[0245] The surface of the middle region 241 of the partition 24 facing the second end face 2212 is planar. The edge region 242 of the partition 24 includes a curved portion 2421, the curved portion 2421 including a convex structure 24211 protruding toward 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 includes two curved portions 2421 oppositely arranged along the width direction of the second end face 2212. The edge region 242 of the partition 24, except for the curved portion 2421, is a planar portion 2422, the surface of the planar portion 2422 facing the second end face 2212 being planar.

[0246] Along the length direction of the second end face 2212, the length of the curved portion 2421 is greater than the length of the middle region 22121 of the second end face 2212; and / or, 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, wherein the middle region 22121 of the second end face 2212 is the region of the second end face 2212 not covered by the first insulating film 23.

[0247] The housing 21 includes a shell 211 having an opening 2111, a cover plate 212 for covering the opening 2111 to form a containing cavity, the first end face 2211 facing the cover plate 212, and the second end face 2212 facing the bottom wall 2112 of the shell 211, and an electrode terminal 214 arranged on the cover plate 212. The battery cell 20 further includes an insulating member 25 fixed to the cover plate 212 and located between the cover plate 212 and the first end face 2211, and the first insulating film 23 adhered to the insulating member 25.

[0248] The battery cell 20 further includes a current collecting member 27 connecting the tab 222 and the electrode terminal 214, and a second insulating film 26 including a body portion 261 arranged between the current collecting member 27 and the insulating member 25 to isolate the current collecting member 27 and the insulating member 25, and an extension portion 262 covering at least part of the large face 2214 of the outer peripheral surface 2213, the first insulating film 23 wrapping and fixing the extension portion 262, and the large face 2214 of the outer peripheral surface 2213 being the face with the largest area of the outer peripheral surface 2213.

[0249] The housing 21 includes a first wall 201 and a second wall 202 intersecting each other and connected by a rounded corner 203, the second end face 2212 facing the second wall 202, and the thickness of the partition 24 being greater than or equal to the radius of the rounded corner 203.

[0250] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them. Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some or all of the technical features can be replaced equivalently. Such modifications or replacements do not change the essence of the corresponding technical solutions, which should be covered in the scope of the present application. In particular, the technical features mentioned in each embodiment can be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized by, The application relates to an electrode assembly set (22) and a battery (1) comprising the same. The battery (1) comprises: a housing (21) having a receiving cavity; an electrode assembly set (22) arranged 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), a second end face (2212) opposite to the first end face (2211), and an outer peripheral surface (2213) connecting the first end face (2211) and the second end face (2212), the tab (222) being located at the first end face (2211); a first insulating film (23) adhered to and covering the outer peripheral surface (2213) and an edge region (22122) of the second end face (2212); 2. The battery cell of claim 1, wherein, a partition (24) adhered to and covering a region of the second end face (2212) not covered by the first insulating film (23), and the partition (24) covering the first insulating film (23).

3. The battery cell of claim 2, wherein, The electrode assembly (220) has a laminated structure.

4. The battery cell of claim 1, wherein, The electrode assembly (220) comprises a first face (2201) and a second face (2202) oppositely arranged along a thickness direction of the electrode assembly (220), and a plurality of fixing structures (2203) arranged at intervals, each of the fixing structures (2203) extending from an edge of the first face (2201) to an edge of the second face (2202) along the thickness direction of the electrode assembly (220), and the first insulating film (23) covering the plurality of fixing structures (2203).

5. The battery cell of claim 4, wherein, The first insulating film (23) comprises at least one insulating sheet (231), and the first insulating film (23) is folded to wrap the outer peripheral surface (2213).

6. The battery cell of claim 5, wherein, The first insulating film (23) comprises two insulating sheets (231), and the two insulating sheets (231) respectively cover two large faces (2214) of the outer peripheral surface (2213) and overlap and are bonded at two side faces (2215) of the outer peripheral surface (2213) to cover the outer peripheral surface (2213), the area of the side face (2215) of the outer peripheral surface (2213) being smaller than the area of the large face (2214) of the outer peripheral surface (2213).

7. The battery cell of claim 1, wherein, The electrode assembly set (22) comprises a first electrode assembly (2201) and a second electrode assembly (2202), and an insulating sheet (231) adhered to a side face of an outer peripheral surface of the first electrode assembly (2201) is adhered to a side face of an outer peripheral surface of the second electrode assembly (2202). A surface of a middle region (241) of the partition (24) facing the second end face (2212) is a plane.

8. The battery cell of claim 1, wherein, The edge region (242) of the separator (24) comprises a bending portion (2421), and the bending portion (2421) comprises a convex structure (24211) protruding towards the second end face (2212) and a concave structure (24212) protruding away from the second end face (2212).

9. The battery cell of claim 8, wherein, The edge region (242) of the separator (24) comprises two bending portions (2421) oppositely arranged along the width direction of the second end face (2212).

10. The battery cell of claim 8, wherein, The part of the edge region (242) of the separator (24) other than the bending portion (2421) is a planar portion (2422), and the surface of the planar portion (2422) facing the second end face (2212) is a plane.

11. The battery cell of claim 8, wherein, Along the length direction of the second end face (2212), the length of the bending portion (2421) is greater than the length of the middle region (22121) of the second end face (2212); and / or, Along the width direction of the second end face (2212), the bending 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), Wherein, the middle region (22121) of the second end face (2212) is a region of the second end face (2212) not covered by the first insulating film (23).

12. The battery cell of any one of claims 1 to 11, wherein, The shell (21) comprises: a housing (211) having an opening (2111); a cover plate (212) for covering the opening (2111) to form the accommodation cavity, the first end face (2211) faces the cover plate (212), and the second end face (2212) faces the bottom wall (2112) of the housing (211); an electrode terminal (214) arranged on the cover plate (212).

13. The battery cell of claim 12, wherein, The battery monomer further comprises: an insulating member (25) fixed to the cover plate (212) and located between the cover plate (212) and the first end face (2211), and the first insulating film (23) is bonded to the insulating member (25).

14. The battery cell of claim 12, wherein, The battery monomer further comprises: a current collecting member (27) connecting the tab (222) and the electrode terminal (214); an insulating member (25) fixed to the cover plate (212) and located between the cover plate (212) and the first end face (2211); A second insulating film (26) includes a body portion (261) and an extension portion (262), the body portion (261) is disposed between the current collecting member (27) and the insulating member (25) to isolate the current collecting member (27) and the insulating member (25), the extension portion (262) covers at least a partial area of a large face (2214) of the outer peripheral surface (2213), the first insulating film (23) wraps and fixes the extension portion (262), and the large face (2214) of the outer peripheral surface (2213) is a face with the largest area of the outer peripheral surface (2213).

15. The battery cell of any one of claims 1-11, wherein, The housing (21) includes intersecting first and second walls (201, 202) connected by a rounded corner (203), the second end face (2212) faces the second wall (202), and the thickness of the partition member (24) is greater than or equal to the radius of the rounded corner (203).

16. The battery cell of any one of claims 1-11, wherein, The thickness of the partition member (24) is in the range of [0.25mm, 0.8mm].

17. The battery cell of any one of claims 1-11, wherein, The thickness of the first insulating film (23) is in the range of [35um, 80um].

18. A battery device characterized by comprising: Comprising: A plurality of battery cells according to any one of claims 1 to 17.

19. An energy storage device, characterized by Comprising: A plurality of battery cells according to any one of claims 1 to 17 or a plurality of battery devices according to claim 18, the battery cells or the battery devices are used to store or provide electrical energy.

20. An energy storage system characterized by, Comprising: A power conversion device; The energy storage device according to claim 19, the power conversion device is used to electrically connect a power generation device and the energy storage device.

21. A charging network characterized in that, Comprising: A charging pile; The energy storage device according to claim 19 or the energy storage system according to claim 20, the energy storage device is used to provide electrical energy for the charging pile.

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