Battery monomer, battery device and electric device

Abstract

The utility model provides a battery monomer, a battery device and a power utilization device. The battery monomer comprises a shell, an electrode unit, an insulating film and an insulating part, wherein the shell comprises a first shell wall and a second shell wall which are arranged in an intersecting manner. The electrode unit is contained in the shell and comprises an electrode body and a tab, and the tab is led out from the electrode body towards the first end face of the first shell wall. The insulating film is accommodated within the housing and is for separating the electrode body from the second housing wall. At least part of the insulating part is located between the electrode body and the second shell wall, and the melting point of the insulating part is larger than that of the insulating film. According to the invention, the reliability of the battery monomer can be effectively improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell, a battery device, and an electrical device. Background Art

[0002] With the development of new energy technology, batteries are used more and more widely, for example, in mobile phones, laptops, electric vehicles, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and power tools.

[0003] In the development of battery technology, the reliability of battery cells directly affects the reliability, cost of use, and user experience of end products. Therefore, how to effectively improve the reliability of battery cells is a technical issue that needs continuous improvement in battery technology. Utility Model Content

[0004] In view of the above problems, the present application provides a battery cell, a battery device and an electrical device, which can effectively improve the reliability of the battery cell.

[0005] In a first aspect, embodiments of the present application provide a battery cell, comprising a housing, an electrode unit, an insulating film, and an insulating member. The housing comprises a first shell wall and a second shell wall disposed intersecting each other. The electrode unit is housed within the housing and comprises an electrode body and a tab, the tab extending from the electrode body toward a first end face of the first shell wall. The insulating film is housed within the housing and serves to separate the electrode body from the second shell wall. At least a portion of the insulating member is positioned between the electrode body and the second shell wall, and the melting point of the insulating member is greater than the melting point of the insulating film.

[0006] The above technical solution arranges an insulating member with a higher melting point between the electrode body and the second shell wall. When the battery cell is heated, the insulating member is not easy to melt. Even if the diaphragm and the insulating film are damaged by heat, the insulating member can still insulate the electrode body and the second shell wall, thereby reducing the risk of short circuit caused by overlap between the electrode body and the second shell wall, and effectively improving the reliability of the battery cell.

[0007] In some embodiments of the first aspect, the insulating member is attached to at least one of the electrode body, the insulating film, and the second shell wall.

[0008] The above technical solution can reduce the difficulty of preparing insulating parts, simplify the preparation process, and help reduce the overall production cost of battery cells.

[0009] In some embodiments of the first aspect, an insulating member is provided between the electrode unit and the insulating film. The insulating film can provide a certain degree of protection for the insulating member, reducing the risk of the insulating member falling off during installation of the electrode unit into the housing. Alternatively, the insulating member is provided between the insulating film and the second housing wall, thereby reducing interference with the assembly of the insulating film and the electrode unit, simplifying the installation of the insulating film, improving the smoothness of the insulating film covering the surface of the electrode unit, and reducing the risk of the insulating member damaging the insulating film.

[0010] In some embodiments of the first aspect, the insulating film and the insulating member are an integrally formed structure.

[0011] On the one hand, there is no need to connect the insulating film and the insulating member through an additional connection process, which simplifies the manufacturing process. At the same time, compared with connecting the insulating film and the insulating member through an additional connection process, the insulating film and the insulating member in an integrated structure have a higher connection strength.

[0012] In some embodiments of the first aspect, the insulating member protrudes from the first end surface along the direction from the electrode body to the first shell wall; and / or, the insulating member protrudes from the second end surface of the electrode body facing away from the first shell wall along the direction from the first shell wall to the electrode body.

[0013] In the above technical solution, the insulating member protrudes from the first end surface, which can increase the coverage area of ​​the insulating member, thereby improving the insulation protection effect of the insulating member at the first end surface, thereby further reducing the overall risk of short circuits caused by the overlap between the electrode body and the second shell wall. The insulating member protrudes from the second end surface, which can increase the coverage area of ​​the insulating member, thereby improving the insulation protection effect of the insulating member at the second end surface, thereby further reducing the overall risk of short circuits caused by the overlap between the electrode body and the second shell wall.

[0014] In some embodiments of the first aspect, the insulating member includes a first portion and a second portion, and the first portion and the second portion are respectively disposed on opposite sides of the electrode body along a thickness direction of the electrode body.

[0015] The above technical solution provides targeted insulation protection for the two opposite sides of the electrode body along its own thickness direction by setting the first part and the second part. On the one hand, the first part and the second part are set separately, which can improve the flexibility of the setting of the insulating parts; on the other hand, it can reduce the amount of insulating parts to a certain extent while meeting the insulation effect requirements, which helps to improve the energy density of the battery cell.

[0016] In some embodiments of the first aspect, a projection of the first portion along the thickness direction and a projection of the second portion along the thickness direction at least partially overlap.

[0017] The above technical solution can improve the overall consistency of the insulating member and the electrode unit in the thickness direction after being matched, reduce the risk of damage to the battery cell due to uneven internal stress of the battery cell caused by expansion of the electrode unit, and further improve the reliability of the battery cell.

[0018] In some embodiments of the first aspect, the first portion covers one side surface of the electrode body along the thickness direction, and the second portion covers the other side surface of the electrode body along the thickness direction.

[0019] The above technical solution can further increase the coverage area of ​​the insulating member, thereby improving the overall insulation protection effect of the insulating member.

[0020] In some embodiments of the first aspect, the electrode unit and the first shell wall are arranged along a first direction, the first direction intersecting with the thickness direction of the electrode body. The insulating member is arranged around the electrode body, and the surrounding axis of the insulating member is parallel to the first direction.

[0021] The above technical solution can not only further increase the coverage of the insulating member to improve the overall insulation protection effect of the insulating member, but also improve the overall stability of the insulating member.

[0022] In some embodiments of the first aspect, the electrode body further includes an outer peripheral surface connected between the first end surface and a second end surface of the electrode body facing away from the first shell wall, and the insulating member covers the outer peripheral surface.

[0023] The coverage of the insulating member can be further increased to further improve the overall insulation protection effect of the insulating member.

[0024] In some embodiments of the first aspect, the electrode unit and the first shell wall are arranged along a first direction, the first direction intersecting the thickness direction of the electrode body. There are multiple insulating members, including a first insulating member and a second insulating member, at least a portion of the first insulating member is arranged along a periphery of the first end surface, and at least a portion of the second insulating member is arranged along a periphery of the second end surface of the first shell wall, facing away from the electrode body.

[0025] The above technical solution provides targeted insulation protection for the first end face and the second end face by setting the first insulating member and the second insulating member. On the one hand, the first insulating member and the second insulating member are set separately, which can improve the flexibility of the overall setting of the insulating member; on the other hand, it can reduce the amount of the overall insulating member to a certain extent while meeting the insulation effect requirements, which helps to improve the energy density of the battery cell.

[0026] In some embodiments of the first aspect, the electrode unit includes at least one electrode assembly, the electrode assembly including a main body and at least one tab, and the electrode body includes the main body of the entire electrode assembly. The electrode assembly includes a straight region and two bent regions, the two bent regions connected to opposite ends of the straight region along the second direction, with the first direction, the second direction, and the thickness direction being perpendicular to each other. At least a portion of the insulating member is located between the straight region and the second shell wall.

[0027] By using insulating parts to specifically insulate and protect the flat areas, the amount of insulating parts used can be reduced to a certain extent while meeting the insulation effect requirements, which helps to improve the energy density of the battery cell.

[0028] In some embodiments of the first aspect, the electrode unit includes at least one electrode assembly, the electrode assembly includes a main body and at least one electrode tab, and the electrode main body includes the main body of all electrode assemblies. The electrode assembly includes a plurality of electrode pieces stacked along the thickness direction. The electrode main body also includes a third end face and a fourth end face, the third end face and the fourth end face are arranged opposite to each other along the second direction, and the first direction, the second direction, and the thickness direction are perpendicular to each other. The insulating member also includes a third insulating member and a fourth insulating member, at least a portion of the third insulating member is arranged along an edge of the third end face, and at least a portion of the fourth insulating member is arranged along an edge of the fourth end face.

[0029] In the case where the electrode unit includes a laminated electrode assembly, the above technical solution further introduces a third insulating member and a fourth insulating member to provide targeted insulation protection for the third end face and the fourth end face respectively, which can improve the overall insulation protection effect of the insulating member.

[0030] In some embodiments of the first aspect, the third insulating member is connected between the first insulating member and the second insulating member, and the fourth insulating member is connected between the first insulating member and the second insulating member.

[0031] The multiple insulating members are connected to each other as a whole, which can further improve the stability of the multiple insulating members as a whole.

[0032] In some embodiments of the first aspect, the first insulating member, the second insulating member, the third insulating member, and the fourth insulating member are an integrally formed structure.

[0033] On the one hand, there is no need to connect the first, second, third, and fourth insulating members through an additional connection process, which simplifies the manufacturing process. At the same time, compared with connecting the first, second, third, and fourth insulating members through an additional connection process, the first, second, third, and fourth insulating members in an integrated structure have a higher connection strength.

[0034] In some embodiments of the first aspect, the volume energy density of the battery cell is less than or equal to 390Wh / L, and the melting point of the insulating member is greater than or equal to 100°C; or, the volume energy density of the battery cell is greater than 390Wh / L, and the melting point of the insulating member is greater than or equal to 150°C.

[0035] The above technical solution can reduce the heat resistance overflow of the insulating component while meeting the insulation protection requirements and reducing costs by setting the melting point of the insulating component in a targeted manner according to the different volume energy densities of the battery cells.

[0036] In some embodiments of the first aspect, the volumetric energy density of the battery cell is less than or equal to 390 Wh / L, and the melting point of the insulating member is greater than or equal to 150° C.; alternatively, the volumetric energy density of the battery cell is greater than 390 Wh / L, and the melting point of the insulating member is greater than or equal to 200° C. By increasing the lower melting point of the insulating member, the insulation protection effect can be further improved.

[0037] In some embodiments of the first aspect, the electrode unit and the first shell wall are arranged along a first direction, the first direction intersecting with a thickness direction of the electrode body. A first dimension d1 of the insulating member along the first direction and a second dimension d2 of the electrode body along the first direction satisfy the relationship: 3 mm ≤ d1 ≤ d2 + 20 mm.

[0038] The above technical solution sets the first dimension d1 of the insulating member along the first direction within the above range, thereby reducing the space occupancy of the insulating member while meeting the coverage requirements of the insulating member, thereby improving the energy density of the battery cell.

[0039] In some embodiments of the first aspect, a first dimension d1 of the insulating member along the first direction and a second dimension d2 of the electrode body along the first direction satisfy the relationship: 5 mm ≤ d1 ≤ d2 + 10 mm.

[0040] The insulating member can further improve the effects of increasing coverage and reducing space occupancy.

[0041] In some embodiments of the first aspect, a third dimension d3 of the insulating member along a thickness direction of the electrode body satisfies the relationship: 0.03 mm ≤ d3 ≤ 1 mm.

[0042] The above technical solution sets the third dimension d3 of the insulating member in the thickness direction of the electrode body within the above range, thereby reducing the space occupancy of the insulating member while meeting the insulation protection effect required, thereby improving the energy density of the battery cell.

[0043] In some embodiments of the first aspect, a third dimension d3 of the insulating member along the thickness direction satisfies the relationship: 0.05 mm ≤ d3 ≤ 0.2 mm.

[0044] It can further improve the insulation protection effect of the insulating part and reduce the space occupancy rate.

[0045] In a second aspect, the present application provides a battery device comprising the battery cell provided in any embodiment of the first aspect.

[0046] In a third aspect, the present application provides an electrical device, which includes a battery cell provided by any embodiment of the first aspect or a battery device provided by any embodiment of the second aspect, and the battery cell or the battery device is used to store or provide electrical energy.

[0047] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0049] Figure 1 A schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0050] Figure 2 A schematic diagram of an exploded structure of a battery device provided in some embodiments of the present application;

[0051] Figure 3 A schematic structural diagram of a battery module provided in some embodiments of the present application;

[0052] Figure 4 A schematic diagram of an exploded structure of a battery cell provided in some embodiments of the present application;

[0053] Figure 5 A schematic diagram of the matching structure of an electrode unit and an insulating member of a battery cell provided in some embodiments of the present application;

[0054] Figure 6 A schematic diagram of the matching structure of an electrode unit and an insulating member of another battery cell provided in some embodiments of the present application;

[0055] Figure 7 A schematic diagram of the coordinated structure of a second shell wall, an insulating film, and an insulating member of a battery cell provided in some embodiments of the present application;

[0056] Figure 8 A schematic diagram of the coordinated structure of a second shell wall, an insulating film, and an insulating member of another battery cell provided in some embodiments of the present application;

[0057] Figure 9 A schematic diagram of the matching structure of a second shell wall and an insulating member of a battery cell provided in some embodiments of the present application;

[0058] Figure 10 A schematic diagram of the matching structure of an electrode unit and an insulating member of another battery cell provided in some embodiments of the present application;

[0059] Figure 11 A schematic diagram of the matching structure of an electrode unit and an insulating member of another battery cell provided in some embodiments of the present application;

[0060] Figure 12 A schematic diagram of an exploded structure of another battery cell provided in some embodiments of the present application;

[0061] Figure 13 A schematic diagram of an exploded structure of another battery cell provided in some embodiments of the present application;

[0062] Figure 14 A schematic diagram of an exploded structure of another battery cell provided in some embodiments of the present application;

[0063] Figure 15 A schematic diagram of the three-dimensional structure of a battery cell provided in some embodiments of the present application;

[0064] Figure 16 for Figure 15 A schematic diagram of the top view of the battery cell shown;

[0065] Figure 17 for Figure 16 Schematic diagram of the cross-section structure along AA;

[0066] Figure 18 for Figure 17 Schematic diagram of the local enlarged structure at H.

[0067] The accompanying drawings in the specific implementation manner are as follows:

[0068] 1. Vehicle; 2. Battery device; 3. Controller; 4. Motor; 5. Housing; 5a. First housing portion; 5b. Second housing portion; 5c. Accommodation space; 6. Battery module; 7. Battery cell;

[0069] 10. Shell; 11. First shell wall; 12. Second shell wall;

[0070] 20, electrode unit; 21, electrode main body; 211, first end surface; 212, second end surface; 213, third end surface; 214, fourth end surface; 22, tab;

[0071] 30, insulating film;

[0072] 40, insulating member; 40a, first insulating member; 40b, second insulating member; 40c, third insulating member; 40d, fourth insulating member; 41, first portion; 42, second portion;

[0073] X, first direction; Y, thickness direction; Z, second direction. DETAILED DESCRIPTION

[0074] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0075] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion. 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, rather than to describe a particular order or primary and secondary relationship.

[0076] 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 appearance of this phrase at various places in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment to other embodiments.

[0077] 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 fixedly connected, or detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0078] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0079] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0080] The term "plurality" used in this application refers to two or more (including two).

[0081] In this application, the term "parallel" includes not only the absolutely parallel situation, but also the roughly parallel situation conventionally recognized in engineering; at the same time, "vertical" also includes not only the absolutely vertical situation, but also the roughly vertical situation conventionally recognized in engineering.

[0082] In the embodiment of the present application, the battery cell may be a secondary battery cell. A secondary battery cell refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0083] The battery cell can be a lithium-ion battery cell, a sodium-ion battery cell, a sodium-lithium-ion battery cell, a lithium metal battery cell, a sodium metal battery cell, a lithium-sulfur battery cell, a magnesium-ion battery cell, a nickel-hydrogen battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, etc., and the embodiments of the present application are not limited to this.

[0084] A battery cell typically includes an electrode assembly. This assembly includes a positive electrode and a negative electrode. During the charge and discharge process of a battery cell, active ions (such as lithium ions) are intercalated and released back and forth between the positive and negative electrodes.

[0085] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0086] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is provided on either or both of the two facing surfaces of the positive electrode current collector.

[0087] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0088] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0089] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material is provided on either or both of the two facing surfaces of the negative electrode current collector.

[0090] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0091] The electrode assembly may be a wound structure, a laminated structure, or a mixed structure of wound and laminated structures.

[0092] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into the wound structure.

[0093] In some embodiments, the electrode assembly is a laminate structure.

[0094] As an example, multiple positive electrode sheets and multiple negative electrode sheets can be provided respectively, and the multiple positive electrode sheets and the multiple negative electrode sheets can be alternately stacked.

[0095] As an example, a plurality of positive electrode sheets may be provided, and the negative electrode sheet may be folded to form a plurality of stacked folded segments, with a positive electrode sheet being sandwiched between adjacent folded segments.

[0096] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of stacked folded segments.

[0097] As an example, a plurality of separators may be provided, each of which is disposed between any adjacent positive electrode sheets or negative electrode sheets.

[0098] As an example, the separator may be provided continuously, and may be provided between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0099] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0100] In some embodiments, the electrode assembly is provided with tabs that can conduct current from the electrode assembly. The tabs include a positive tab and a negative tab.

[0101] In some embodiments, the battery cell may include an outer shell. The outer shell may be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film. In some embodiments, the outer shell may be a sealed structure or a non-sealed structure. As an example, when the outer shell is a non-sealed structure, the outer shell serves to protect the electrode assembly, and a sealing bag is further included between the outer shell and the electrode assembly, which is used to encapsulate the electrode assembly and the electrolyte. Specifically, the sealing bag may be a bag-shaped insulating member or an aluminum-plastic film. When the outer shell is a sealed structure, it is used to encapsulate components such as the electrode assembly and the electrolyte.

[0102] As an example, the battery cells may be cylindrical, prismatic, soft-pack or other shaped battery cells. Prismatic battery cells include square-shell, blade-shaped, and polygonal batteries. Polygonal batteries may be, for example, hexagonal batteries.

[0103] In some embodiments, the housing includes an end cap and a shell, wherein the shell has an opening and the end cap covers the opening. The shell may have one or more openings. One or more end caps may also be provided.

[0104] In some embodiments, the housing is provided with at least one electrode terminal, which is electrically connected to the tab. The electrode terminal may be directly connected to the tab or indirectly connected to the tab via a current collecting member. The electrode terminal may be provided on an end cap or on the housing.

[0105] The battery apparatus mentioned in the embodiments of the present application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include multiple battery cells, which are connected in series, parallel, or hybrid via a busbar.

[0106] In some embodiments, a battery cell assembly is generally formed by arranging a plurality of battery cells.

[0107] As an example, the battery cell assembly may be a battery module, which is formed by arranging and fixing multiple battery cells to form an independent module. As an example, the battery module may be formed by bundling multiple battery cells with a cable tie.

[0108] In some embodiments, the battery device may be a battery pack, which includes a case and one or more battery cell assemblies, wherein the battery cell assemblies are housed in the case.

[0109] As an example, the battery cell assembly may be a battery module, and the battery cell assembly may be accommodated in the box by fixing the battery module in the box.

[0110] As an example, the battery cell assembly may also be housed in the box by directly fixing the plurality of battery cells to the box.

[0111] As an example, the box may include a top cover, a frame, and a bottom plate, wherein the top cover and the bottom plate are respectively connected to the frame to form a closed space inside the box to accommodate the battery cell assembly.

[0112] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0113] The technical solutions described in the embodiments of the present application are applicable to various electrical devices that use battery cells, such as mobile phones, portable devices, laptop computers, electric vehicles, electric toys, electric tools, vehicles, ships and spacecraft, for example, spacecraft include airplanes, rockets, space shuttles and spacecraft, etc.

[0114] With the development of new energy technology, batteries are used more and more widely, for example, in mobile phones, laptops, electric vehicles, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and power tools.

[0115] In the development of battery technology, the reliability of battery cells directly impacts the reliability, cost, and user experience of end products. Currently, when battery cells are heated, the separators of the electrode assemblies and the insulating film covering the electrode assemblies are easily damaged. This can lead to the risk of short circuits caused by overlapping of the electrode sheets and the outer casing, seriously impacting the reliability of the battery cells.

[0116] Based on the above considerations, an embodiment of the present application provides a battery cell, comprising a housing, an electrode unit, an insulating film, and an insulating member. The housing comprises a first shell wall and a second shell wall arranged to intersect each other. The electrode unit is housed within the housing and comprises an electrode body and a tab, the tab extending from the electrode body toward a first end face of the first shell wall. The insulating film is housed within the housing and serves to separate the electrode body from the second shell wall. At least a portion of the insulating member is located between the electrode body and the second shell wall, and the melting point of the insulating member is greater than the melting point of the insulating film.

[0117] The above technical solution arranges an insulating member with a higher melting point between the electrode body and the second shell wall. When the battery cell is heated, the insulating member is not easy to melt. Even if the diaphragm and the insulating film are damaged by heat, the insulating member can still insulate the electrode body and the second shell wall, thereby reducing the risk of short circuit caused by overlap between the electrode body and the second shell wall, and effectively improving the reliability of the battery cell.

[0118] The battery cells provided in the embodiments of the present application are introduced below with reference to the accompanying drawings.

[0119] Figure 1 A schematic structural diagram of a vehicle provided for some embodiments of the present application.

[0120] Continue to refer Figure 1 The vehicle 1 is provided with a battery device 2 inside. The battery device 2 can be provided at the bottom, head, or tail of the vehicle 1. The battery device 2 can be used to power the vehicle 1. For example, the battery device 2 can serve as an operating power source for the vehicle 1.

[0121] The vehicle 1 may further include a controller 3 and a motor 4 . The controller 3 is used to control the battery device 2 to supply power to the motor 4 , for example, to meet the power requirements of the vehicle 1 during startup, navigation, and driving.

[0122] In some embodiments of the present application, the battery device 2 can not only serve as the operating power source of the vehicle 1, but also serve as the driving power source of the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0123] Figure 2 Schematic diagram of an explosion of a battery device provided in some embodiments of the present application.

[0124] Continue to refer Figure 2 The battery device 2 includes a box body 5 and a battery cell, and the battery cell is accommodated in the box body 5.

[0125] The housing 5 is used to house battery cells and can have various structures. In some embodiments, the housing 5 can include a first housing portion 5a and a second housing portion 5b. The first housing portion 5a and the second housing portion 5b overlap each other, and the first housing portion 5a and the second housing portion 5b together define a storage space 5c for accommodating the battery cells. The second housing portion 5b can be a hollow structure with one end open. The first housing portion 5a is a plate-like structure, and the first housing portion 5a overlaps the open side of the second housing portion 5b to form the housing 5 with the storage space 5c. The first housing portion 5a and the second housing portion 5b can also be hollow structures with one end open. The open side of the first housing portion 5a overlaps the open side of the second housing portion 5b to form the housing 5 with the storage space 5c. Of course, the first housing portion 5a and the second housing portion 5b can have various shapes, such as a cylinder, a rectangular parallelepiped, etc.

[0126] In order to improve the sealing performance after the first box body 5a and the second box body 5b are connected, a sealing member, such as a sealant, a sealing ring, etc., may also be provided between the first box body 5a and the second box body 5b.

[0127] Assuming that the first box body portion 5a covers the top of the second box body portion 5b, the first box body portion 5a can also be called an upper box cover, and the second box body portion 5b can also be called a lower box body.

[0128] In the battery device 2, there can be one or more battery cells. If there are multiple battery cells, they can be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections. Multiple battery cells can be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery unit can be housed within the housing 5. Alternatively, multiple battery cells can be first connected in series, in parallel, or in a hybrid connection to form a battery module 6, and then the multiple battery modules 6 can be connected in series, in parallel, or in a hybrid connection to form a single unit and housed within the housing 5.

[0129] Figure 3 for Figure 2 The schematic diagram of the battery module is shown.

[0130] In some embodiments, continue to refer to Figure 3 There are multiple battery cells 7, and the multiple battery cells 7 are first connected in series, in parallel, or in mixed series to form a battery module 6. The multiple battery modules 6 are then connected in series, in parallel, or in mixed series to form a whole, and are accommodated in the box.

[0131] The multiple battery cells 7 in the battery module 6 can be electrically connected via a busbar component to achieve parallel connection, series connection, or mixed connection of the multiple battery cells 7 in the battery module 6 .

[0132] Figure 4 This is a schematic diagram of the explosion structure of a battery cell provided in some embodiments of the present application. Figure 5 This is a schematic diagram of the matching structure of an electrode unit and an insulating member of a battery cell provided in some embodiments of the present application. Figure 6 This is a schematic diagram of the matching structure of the electrode unit and the insulating member of another battery cell provided in some embodiments of the present application.

[0133] Continue to refer Figures 4 to 6The embodiment of the present application provides a battery cell 7, which includes a shell 10, an electrode unit 20, an insulating film 30 and an insulating member 40. The shell 10 includes a first shell wall 11 and a second shell wall 12 arranged to intersect. The electrode unit 20 is accommodated in the shell 10, and the electrode unit 20 includes an electrode body 21 and a tab 22. The tab 22 extends from the electrode body 21 toward the first end surface 211 of the first shell wall 11. The insulating film 30 is accommodated in the shell 10 and is used to separate the electrode body 21 from the second shell wall 12. At least a portion of the insulating member 40 is located between the electrode body 21 and the second shell wall 12, and the melting point of the insulating member 40 is greater than the melting point of the insulating film 30.

[0134] Exemplarily, the housing 10 is a component used to create an internal environment for the battery cell 7. This internal environment can accommodate the electrode assembly, electrolyte, and other components. Optionally, the housing 10 can be made of, but is not limited to, metal or non-metallic materials. For example, metal materials can include copper, aluminum, or stainless steel; non-metallic materials can include polyethylene, polypropylene, or polyvinyl chloride.

[0135] In some examples, the housing 10 includes a shell and an end cover, wherein the shell has an opening and the end cover covers the opening.

[0136] The shell is a component used to cooperate with the end cap to form the internal environment of the battery cell 7. The internal environment formed can be used to accommodate the electrode assembly, electrolyte and other components. The shell and the end cap can be independent components. An opening can be set in the shell, and the internal environment of the battery cell 7 is formed by covering the opening with the end cap. Optionally, the end cap and the shell can be integrated. Specifically, the end cap and the shell can form a common connection surface before other components are put into the shell. When the interior of the shell needs to be encapsulated, the end cap is covered with the shell. The shell can be of various shapes and sizes, such as rectangular, cylindrical, hexagonal, etc. Specifically, the shape of the shell can be determined according to the specific shape and size of the electrode assembly. The material of the shell can be various. For example, the shell can be made of, but not limited to, metal or non-metallic materials. For example, the metal material can be copper, aluminum or stainless steel, etc.; the non-metallic material can be polyethylene, polypropylene or polyvinyl chloride, etc.

[0137] The end cap refers to a component that covers the opening of the shell to isolate the internal environment of the battery cell 7 from the external environment. Optionally, the shape of the end cap can be adapted to the shape of the shell to match the shell. Optionally, the end cap can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap is not easily deformed when squeezed or collided, so that the battery cell 7 can have a higher structural strength and the reliability can also be improved. Functional components such as terminal groups can be provided on the end cap. The material of the end cap can also be various. For example, the end cap can be but not limited to being made of metal or non-metallic materials. For example, the metal material can be copper, aluminum or stainless steel, etc.; the non-metallic material can be polyethylene, polypropylene or polyvinyl chloride, etc.

[0138] Optionally, the end cap may be detachably connected to the housing or integrally formed on the housing. The end cap may be directly connected to the housing or secured to the housing via other components. For example, the end cap and the housing may be connected by, but is not limited to, welding, riveting, or bonding.

[0139] Electrode terminals, a pressure relief mechanism, a liquid injection hole, etc. may be provided on the first shell wall 11. As an example, the first shell wall 11 is an end cover.

[0140] The second shell wall 12 may be at least a portion of the circumferential side wall of the housing 10. As an example, the housing includes the second shell wall 12, and the housing is in the shape of a rectangular parallelepiped. The second shell wall 12 may be one of the four side walls of the housing along its own circumference, or may be the four side walls of the housing along its own circumference, or may be the entire housing.

[0141] The electrode unit 20 includes at least one electrode assembly, which includes a main body and at least one tab 22. The electrode main body 21 includes the main body of the entire electrode assembly. The electrode assembly is the component in the battery cell 7 where the electrochemical reaction occurs. The electrode assembly is mainly formed by winding or stacking positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets. The parts of the positive and negative electrode sheets with active materials constitute the main body of the electrode assembly, and the parts of the positive and negative electrode sheets without active materials each constitute a tab 22. The positive and negative electrode tabs can be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery, the positive and negative electrode active materials react with the electrolyte, and the tabs 22 connect the electrode terminals to form a current circuit.

[0142] The insulating film 30 is used to insulate the electrode body 21 from the second shell wall 12 . In some examples, the insulating film 30 covers at least a portion of the outer surface of the electrode body 21 .

[0143] Optionally, the insulating film 30 may be made of, but is not limited to, polyethylene, polypropylene, polyethylene terephthalate, rubber or the like.

[0144] At least part of the insulating member 40 is located between the electrode body 21 and the second shell wall 12 . It can be understood that part of the insulating member 40 is located between the electrode body 21 and the second shell wall 12 , or the entire insulating member 40 is located between the electrode body 21 and the second shell wall 12 .

[0145] The melting point of the insulating member 40 is higher than that of the insulating film 30 , so that the insulating member 40 has stronger heat resistance than the insulating film 30 . In a high temperature environment, the insulating member 40 is less likely to melt.

[0146] Optionally, the insulating member 40 may be, but is not limited to, a sheet-like structure, a film-layer structure, or a block-like structure.

[0147] Optionally, the insulating member 40 may be made of, but is not limited to, polytetrafluoroethylene, polyimide, mica, or glass fiber.

[0148] The above technical solution arranges an insulating member 40 with a relatively high melting point between the electrode body 21 and the second shell wall 12. When the battery cell 7 is heated, the insulating member 40 is not easy to melt. Even if the diaphragm and the insulating film 30 are damaged by heat, the insulating member 40 can still insulate the electrode body 21 and the second shell wall 12, thereby reducing the risk of short circuit caused by overlap between the electrode body 21 and the second shell wall 12, and effectively improving the reliability of the battery cell 7.

[0149] Figure 7 This is a schematic diagram of the coordinated structure of the second shell wall 12, the insulating film 30, and the insulating member 40 of a battery cell 7 provided in some embodiments of the present application. Figure 8 This is a schematic diagram of the coordination structure of the second shell wall 12, the insulating film 30 and the insulating member 40 of another battery cell 7 provided in some embodiments of the present application. Figure 9 This is a schematic diagram of the matching structure of the second shell wall 12 and the insulating member 40 of a battery cell 7 provided in some embodiments of the present application.

[0150] Continue to refer Figures 7 to 9 In some embodiments, the insulating member 40 is attached to at least one of the electrode body 21 , the insulating film 30 , and the second shell wall 12 .

[0151] Illustratively, attaching means adhering or coating or spraying.

[0152] In some examples, such as Figures 4 to 11 As shown, the insulating member 40 is attached to a surface of the electrode body 21 on one side facing the insulating film 30 .

[0153] In some examples, such as Figure 12 As shown, the insulating member 40 is attached to the surface of the insulating film 30 facing the second housing wall 12 .

[0154] In some examples, such as Figure 13 As shown, the insulating member 40 is attached to a surface of the insulating film 30 on one side facing the electrode body 21 .

[0155] In some examples, such as Figure 14 As shown, the insulating member 40 is attached to a surface of the second shell wall 12 facing the electrode body 21 .

[0156] The above technical solution can reduce the difficulty of preparing the insulating member 40 , simplify the preparation process, and help reduce the overall production cost of the battery cell 7 .

[0157] In some embodiments, an insulating member 40 is disposed between the electrode unit 20 and the insulating film 30 .

[0158] Exemplarily, the insulating member 40 is connected to the surface of the electrode unit 20 facing the insulating film 30 and is located between the electrode unit 20 and the insulating film 30. The insulating member 40 may be directly connected to the surface of the electrode unit 20 facing the insulating film 30, or may be restricted to the surface of the electrode unit 20 facing the insulating film 30 by other components.

[0159] The insulating film 30 of the above technical solution can play a certain protective role on the insulating member 40 , reducing the risk of the insulating member 40 falling off when the electrode unit 20 is installed in the housing 10 .

[0160] In some embodiments, an insulating member 40 is disposed between the insulating film 30 and the second shell wall 12 .

[0161] Illustratively, the insulating member 40 is connected to a surface of the second shell wall 12 facing the insulating film 30 and is located between the insulating film 30 and the second shell wall 12. The insulating member 40 may be directly connected to the surface of the second shell wall 12 facing the insulating film 30, or may be restricted to the surface of the second shell wall 12 facing the insulating film 30 by other components.

[0162] The above technical solution can reduce the interference effect of the insulating part 40 on the assembly of the insulating film 30 and the electrode unit 20, reduce the difficulty of setting the insulating film 30, and not only improve the flatness of the insulating film 30 on the surface of the electrode unit 20, but also reduce the risk of the insulating part 40 damaging the insulating film 30.

[0163] In some embodiments, the insulating film 30 and the insulating member 40 are an integrally formed structure.

[0164] Exemplarily, the insulating film 30 and the insulating member 40 are simultaneously prepared by using a composite material having two or more insulating materials with different melting points.

[0165] On the one hand, there is no need to connect the insulating film 30 and the insulating member 40 through an additional connection process, which simplifies the manufacturing process. At the same time, compared with connecting the insulating film 30 and the insulating member 40 through an additional connection process, the insulating film 30 and the insulating member 40 in an integrated structure have a higher connection strength.

[0166] In some embodiments, along the direction from the electrode body 21 to the first shell wall 11 , the insulating member 40 protrudes from the first end surface 211 .

[0167] It should be noted that the diaphragm is prone to shrinkage in a high temperature environment. The pole ear 22 is led out from the first end face 211, and the free end of the diaphragm is located at the first end face 211 and the second end face 212, so that the larger risk area of ​​overlap between the pole piece and the second shell wall 12 is located at the first end face 211 and the second end face 212.

[0168] In this way, the insulating member 40 of the above technical solution protrudes from the first end face 211, which can increase the coverage area of ​​the insulating member 40, thereby improving the insulation protection effect of the insulating member 40 on the position of the first end face 211, thereby further reducing the overall risk of short circuit caused by the overlap between the electrode body 21 and the second shell wall 12.

[0169] In some embodiments, along the direction from the first shell wall 11 to the electrode body 21 , the insulating member 40 protrudes from the second end surface 212 of the electrode body 21 facing away from the first shell wall 11 .

[0170] The insulating member 40 protrudes from the second end surface 212, which can increase the coverage area of ​​the insulating member 40, thereby improving the insulation protection effect of the insulating member 40 on the second end surface 212, thereby further reducing the overall risk of short circuit caused by the overlap between the electrode body 21 and the second shell wall 12.

[0171] In some embodiments, the insulating member 40 includes a first portion 41 and a second portion 42 , and the first portion 41 and the second portion 42 are respectively disposed on opposite sides of the electrode body 21 along the thickness direction Y thereof.

[0172] It should be noted that the two opposite surfaces of the electrode body 21 along the thickness direction Y refer to the large surfaces of the electrode body 21. These two opposite surfaces of the electrode body 21 along the thickness direction Y often abut the second shell wall 12. Furthermore, during the cycling of the battery cell 7, the electrode body 21 expands relatively significantly along the thickness direction Y, resulting in a tighter abutment with the second shell wall 12. Therefore, when the battery cell 7 is exposed to high temperatures, the risk of overlap between the two sides of the electrode body 21 along the thickness direction Y and the second shell wall 12 is relatively high.

[0173] The above technical solution provides targeted insulation protection for the two opposite sides of the electrode body 21 along its own thickness direction Y by setting the first part 41 and the second part 42. On the one hand, the first part 41 and the second part 42 are set separately, which can improve the flexibility of the setting of the insulating part 40; on the other hand, it can reduce the amount of the insulating part 40 to a certain extent while meeting the insulation effect requirements, which helps to improve the energy density of the battery cell 7.

[0174] The first portion 41 and the second portion 42 may be made of the same material, shape, and size, or may be different. In some examples, the first portion 41 and the second portion 42 are made of the same material, shape, and size, which helps simplify the manufacturing process of the insulating member 40 and reduce costs.

[0175] In some embodiments, a projection of the first portion 41 along the thickness direction Y and a projection of the second portion 42 along the thickness direction Y at least partially overlap.

[0176] For example, the projection of the first part 41 along the thickness direction Y and the projection of the second part 42 along the thickness direction Y may partially overlap, or the projection of the first part 41 along the thickness direction Y and the projection of the second part 42 along the thickness direction Y may overlap.

[0177] The above technical solution can improve the overall consistency of the insulating part 40 and the electrode unit 20 in the thickness direction Y after being matched, reduce the risk of damage to the battery cell 7 caused by uneven internal stress of the battery cell 7 due to expansion of the electrode unit 20, and further improve the reliability of the battery cell 7.

[0178] In some embodiments, the first portion 41 covers one side surface of the electrode body 21 along the thickness direction Y. The second portion 42 covers the other side surface of the electrode body 21 along the thickness direction Y.

[0179] Exemplarily, the first portion 41 covers one side surface of the electrode body 21 in the thickness direction Y, which means that the first portion 41 covers the entire surface of the electrode body 21 on one side in the thickness direction Y. The second portion 42 covers the other side surface of the electrode body 21 in the thickness direction Y, which means that the second portion 42 covers the entire surface of the other side of the electrode body 21 in the thickness direction Y.

[0180] The above technical solution can further increase the coverage area of ​​the insulating member 40 , thereby improving the overall insulation protection effect of the insulating member 40 .

[0181] Figure 10 A schematic diagram of the matching structure of an electrode unit and an insulating member of another battery cell provided in some embodiments of the present application.

[0182] Continue to refer Figure 10In some embodiments, the electrode unit 20 and the first shell wall 11 are arranged along a first direction X, which intersects with a thickness direction Y of the electrode body 21. The insulating member 40 is arranged around the electrode body 21, and the surrounding axis of the insulating member 40 is parallel to the first direction X.

[0183] The insulating member 40 is disposed around the electrode body 21. In other words, the insulating member 40 is annular and is disposed around the outer circumference of the electrode body 21. This allows the insulating member 40 to be located not only on opposite sides of the electrode body 21 along its thickness direction Y, but also on opposite sides of the electrode body 21 along the second direction Z. The first direction X, the second direction Z, and the thickness direction Y are perpendicular to each other.

[0184] The above technical solution can not only further increase the coverage of the insulating member 40 to improve the overall insulation protection effect of the insulating member 40 , but also improve the overall stability of the insulating member 40 .

[0185] Figure 11 This is a schematic diagram of the matching structure of an electrode unit and an insulating member of another battery cell provided in some embodiments of the present application.

[0186] Continue to refer Figure 11 In some embodiments, the electrode body 21 further includes an outer peripheral surface connected between the first end surface 211 and the second end surface 212 of the electrode body 21 facing away from the first shell wall 11 , and the insulating member 40 covers the outer peripheral surface.

[0187] The insulating member 40 covers the outer circumference, which means that the insulating member 40 is annularly sleeved around the outer circumference of the electrode body 21 and covers the entire outer circumference of the electrode body 21. This can further increase the coverage of the insulating member 40 and further improve the overall insulation protection effect of the insulating member 40.

[0188] Figure 12 This is a schematic diagram of the explosion structure of another battery cell provided in some embodiments of the present application. Figure 13 A schematic diagram of the explosion structure of another battery cell provided in some embodiments of the present application.

[0189] Continue to refer Figures 12 to 13 In some embodiments, the electrode unit 20 and the first shell wall 11 are arranged along a first direction X, which intersects with a thickness direction Y of the electrode body 21. There are multiple insulating members 40, each of which includes a first insulating member 40a and a second insulating member 40b. At least a portion of the first insulating member 40a is arranged along the periphery of the first end surface 211, and at least a portion of the second insulating member 40b is arranged along the periphery of the electrode body 21 away from the second end surface 212 of the first shell wall 11.

[0190] Exemplarily, the number of the insulating pieces 40 can be, but is not limited to, two, three, four or more. The number of the first insulating pieces 40a can be, but is not limited to, one, two, three or more, and the number of the second insulating pieces 40b can be, but is not limited to, one, two, three or more.

[0191] As described above, the diaphragm is prone to shrinkage in a high-temperature environment, and the tab 22 is led out from the first end face 211, and the free end of the diaphragm is located at the positions of the first end face 211 and the second end face 212, so that a larger risk area of the tab lapping with the second shell wall 12 is located at the positions of the first end face 211 and the second end face 212.

[0192] The above technical solution insulates and protects the positions of the first end face 211 and the second end face 212 by setting the first insulating piece 40a and the second insulating piece 40b. On the one hand, the first insulating piece 40a and the second insulating piece 40b are set in a split manner, which can improve the flexibility of the overall setting of the insulating piece 40. On the other hand, the amount of the overall insulating piece 40 can be reduced to a certain extent while meeting the insulation effect requirements, which helps to improve the energy density of the battery monomer 7.

[0193] It should be noted that the "first" and "second" in the first insulating piece 40a and the second insulating piece 40b are only used to distinguish the different positions of the insulating piece 40, that is, the first insulating piece 40a can be understood as the insulating piece 40 arranged along the outer periphery of the first end face 211, and the second insulating piece 40b can be understood as the insulating piece 40 arranged along the outer periphery of the second end face 212.

[0194] The structural details of the first insulating piece 40a and the second insulating piece 40b are the same as those of the aforementioned insulating piece 40.

[0195] In some embodiments, the first insulating piece 40a protrudes from the first end face 211 in a direction of the electrode body 21 pointing to the first shell wall 11.

[0196] In some embodiments, the second insulating piece 40b protrudes from the second end face 212 of the electrode body 21 away from the first shell wall 11 in a direction of the first shell wall 11 pointing to the electrode body 21.

[0197] In some embodiments, the first insulating piece 40a includes a first portion 41 and a second portion 42, and the first portion 41 and the second portion 42 are respectively arranged on two opposite sides of the electrode body 21 along the thickness direction Y thereof.

[0198] In some embodiments, the second insulating piece 40b includes a first portion 41 and a second portion 42, and the first portion 41 and the second portion 42 are respectively arranged on two opposite sides of the electrode body 21 along the thickness direction Y thereof.

[0199] In some embodiments, the first insulating member 40 a is disposed around the electrode body 21 , and the surrounding axis of the first insulating member 40 a is parallel to the first direction X.

[0200] In some embodiments, the second insulating member 40 b is disposed around the electrode body 21 , and the surrounding axis of the second insulating member 40 b is parallel to the first direction X.

[0201] In some embodiments, the electrode unit 20 includes at least one electrode assembly, each comprising a main body and at least one tab 22. The electrode body 21 comprises the entire main body of the electrode assembly. The electrode assembly includes a straight region and two bent regions, the two bent regions connected to the ends of the straight region along the second direction Z. The first direction X, the second direction Z, and the thickness direction Y are perpendicular to each other. At least a portion of the insulating member 40 is located between the straight region and the second shell wall 12.

[0202] For example, in a wound electrode assembly, the free ends of the diaphragm are located at two opposite end surfaces of the electrode assembly in the first direction X. That is, when the electrode unit 20 includes a wound electrode assembly, the free ends of the diaphragm are located at the first end surface 211 and the second end surface 212, respectively. The diaphragm is prone to shrinkage in high-temperature environments, resulting in a greater risk of overlap between the electrode piece and the second shell wall 12 being located at the first end surface 211 and the second end surface 212.

[0203] In this way, when the electrode unit 20 includes a wound electrode assembly, targeted insulation protection is performed on the first end face 211 and the second end face 212, which can reduce the use of the overall insulating part 40 to a certain extent while meeting the insulation effect requirements, thereby helping to improve the energy density of the battery cell 7.

[0204] Moreover, during the cycle of the battery cell 7, the expansion of the straight area along its own thickness direction Y is also relatively large, making the contact between the straight area and the second shell wall 12 tighter. Therefore, when the battery cell 7 is in a high temperature environment, the risk of overlap between the two sides of the straight area along its own thickness direction Y and the second shell wall 12 is relatively large.

[0205] In this way, by using the insulating member 40 to specifically insulate and protect the flat area, the amount of the insulating member 40 can be reduced to a certain extent while meeting the insulation effect requirements, which helps to improve the energy density of the battery cell 7.

[0206] Figure 14 A schematic diagram of the explosion structure of another battery cell provided in some embodiments of the present application.

[0207] Continue to refer Figure 14In some embodiments, the electrode unit 20 includes at least one electrode assembly, the electrode assembly includes a main body and at least one electrode tab 22, and the electrode body 21 includes the main body of all electrode assemblies. The electrode assembly includes a plurality of electrode pieces stacked along the thickness direction Y. The electrode body 21 also includes a third end face 213 and a fourth end face 214, the third end face 213 and the fourth end face 214 are arranged opposite to each other along the second direction Z, and the first direction X, the second direction Z and the thickness direction Y are perpendicular to each other. The insulating member 40 also includes a third insulating member 40c and a fourth insulating member 40d, at least a portion of the third insulating member 40c is arranged along the edge of the third end face 213, and at least a portion of the fourth insulating member 40d is arranged along the edge of the fourth end face 214.

[0208] For example, the number of the third insulating members 40 c may be, but is not limited to, one, two, three or more, and the number of the fourth insulating members 40 d may be, but is not limited to, one, two, three or more.

[0209] The electrode assembly includes a plurality of electrode sheets stacked along a thickness direction Y. In other words, the electrode assembly is a laminated electrode assembly. In a laminated electrode assembly, the free ends of the diaphragm are located not only at two opposite end surfaces of the electrode assembly in a first direction X, but also at two opposite end surfaces of the electrode assembly in a second direction Z.

[0210] In other words, when the electrode unit 20 includes a laminated electrode assembly, the free ends of the diaphragm are respectively located at the first end surface 211, the second end surface 212, the third end surface 213, and the fourth end surface 214. The diaphragm is prone to shrinkage in a high-temperature environment, so that the areas with a greater risk of overlapping between the electrode piece and the second shell wall 12 are located at the first end surface 211, the second end surface 212, the third end surface 213, and the fourth end surface 214 of the electrode assembly.

[0211] In this way, the above technical solution further introduces the third insulating member 40c and the fourth insulating member 40d to provide targeted insulation protection for the third end face 213 and the fourth end face 214 respectively when the electrode unit 20 includes a laminated electrode assembly, which can improve the overall insulation protection effect of the insulating member 40.

[0212] It should be noted that the "third" and "fourth" in the third insulating member 40c and the fourth insulating member 40d are only used to distinguish the different positions of the insulating member 40. That is, the third insulating member 40c can be understood as the insulating member 40 arranged along the periphery of the third end face 213, and the fourth insulating member 40d can be understood as the insulating member 40 arranged along the periphery of the fourth end face 214.

[0213] The structural details of the third insulating member 40 c and the fourth insulating member 40 d are the same as those of the aforementioned insulating member 40 .

[0214] In some embodiments, along the second direction Z, the third insulating member 40 c protrudes from the third end surface 213 .

[0215] In some embodiments, along the second direction Z, the fourth insulating member 40 d protrudes from the fourth end surface 214 .

[0216] In some embodiments, the third insulating member 40 c includes a first portion 41 and a second portion 42 , and the first portion 41 and the second portion 42 are respectively disposed on opposite sides of the electrode body 21 along the thickness direction Y thereof.

[0217] In some embodiments, the fourth insulating member 40 d includes a first portion 41 and a second portion 42 , and the first portion 41 and the second portion 42 are respectively disposed on opposite sides of the electrode body 21 along the thickness direction Y thereof.

[0218] In some embodiments, the third insulating member 40 c is disposed around the electrode body 21 , and the surrounding axis of the third insulating member 40 c is parallel to the second direction Z.

[0219] In some embodiments, the third insulating member 40 c is disposed around the electrode body 21 , and the surrounding axis of the third insulating member 40 c is parallel to the second direction Z.

[0220] In some embodiments, the third insulating member 40c is connected between the first insulating member 40a and the second insulating member 40b, and the fourth insulating member 40d is connected between the first insulating member 40a and the second insulating member 40b. In other words, the multiple insulating members 40 are connected to form a whole, which can further improve the stability of the multiple insulating members 40 as a whole.

[0221] For example, the third insulating member 40c may be directly connected between the first insulating member 40a and the second insulating member 40b, or may be restricted between the first insulating member 40a and the second insulating member 40b by other components.

[0222] In some embodiments, the first insulating member 40a, the second insulating member 40b, the third insulating member 40c, and the fourth insulating member 40d are an integrally formed structure.

[0223] On the one hand, there is no need to connect the first insulating member 40a, the second insulating member 40b, the third insulating member 40c, and the fourth insulating member 40d through an additional connection process, which simplifies the manufacturing process. Furthermore, compared to connecting the first insulating member 40a, the second insulating member 40b, the third insulating member 40c, and the fourth insulating member 40d through an additional connection process, the integrated structure of the first insulating member 40a, the second insulating member 40b, the third insulating member 40c, and the fourth insulating member 40d has a higher connection strength.

[0224] In some embodiments, the volume energy density of the battery cell 7 is less than or equal to 390Wh / L, and the melting point of the insulating member 40 is greater than or equal to 100° C. Alternatively, the volume energy density of the battery cell 7 is greater than 390Wh / L, and the melting point of the insulating member 40 is greater than or equal to 150° C.

[0225] Illustratively, when the volume energy density of the battery cell 7 is less than or equal to 390Wh / L, the melting point of the insulating member 40 may be, but is not limited to, 100°C, 120°C, 140°C, 160°C, 180°C, 200°C, 250°C, 300°C, 350°C, 400°C, 450°C, 500°C, etc.

[0226] When the volume energy density of the battery cell 7 is greater than 390Wh / L, the melting point of the insulating member 40 may be, but is not limited to, 150°C, 190°C, 200°C, 220°C, 260°C, 280°C, 300°C, 320°C, 360°C, 380°C, 400°C, 450°C, 500°C, 550°C, 600°C,

[0227] 700℃, 800℃, etc.

[0228] It is understood that the higher the volumetric energy density of the battery cell 7, the higher the temperature of the battery cell 7 after thermal runaway occurs, and the higher the melting point requirement for the insulating member 40. The lower the volumetric energy density of the battery cell 7, the lower the temperature of the battery cell 7 after thermal runaway occurs, and the lower the melting point requirement for the insulating member 40.

[0229] The above technical solution can reduce the heat resistance overflow of the insulating member 40 and reduce costs while meeting the insulation protection requirements by setting the melting point of the insulating member 40 according to the different volume energy densities of the battery cells 7.

[0230] In some embodiments, the volumetric energy density of the battery cell 7 is less than or equal to 390Wh / L, and the melting point of the insulating member 40 is greater than or equal to 150°C. Alternatively, the volumetric energy density of the battery cell 7 is greater than 390Wh / L, and the melting point of the insulating member 40 is greater than or equal to 200°C. By increasing the lower melting point of the insulating member 40, the insulation protection effect can be further improved.

[0231] Figure 15 This is a schematic diagram of a three-dimensional structure of a battery cell provided in some embodiments of the present application. Figure 16 for Figure 15 The schematic diagram of the top view of the battery cell shown in FIG. Figure 17 for Figure 16 Schematic diagram of the cross-section structure along AA, Figure 18 for Figure 17 Schematic diagram of the local enlarged structure at H.

[0232] Continue to refer Figures 15 to 18 In some embodiments, the electrode unit 20 and the first shell wall 11 are arranged along a first direction X, and the first direction X intersects with a thickness direction Y of the electrode body 21. A first dimension d1 of the insulating member 40 along the first direction X and a second dimension d2 of the electrode body 21 along the first direction X satisfy the relationship: 3 mm ≤ d1 ≤ d2 + 20 mm.

[0233] Exemplarily, the first dimension d1 of the insulating member 40 along the first direction X may be understood as the width of the insulating member 40 , and the second dimension d2 of the electrode body 21 along the first direction X may be understood as the height of the electrode body 21 .

[0234] As an example, the first dimension d1 of the insulating member 40 along the first direction X may be, but is not limited to, 3 mm, 6 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, etc.

[0235] It is understandable that the larger the first dimension d1 of the insulating member 40 along the first direction X, the larger the coverage area of ​​the insulating member 40 and the lower the difficulty of installation. At the same time, the greater the extent to which the insulating member 40 extends beyond the electrode body 21 in the first direction X, the greater the internal space occupied by the insulating member 40 in the battery cell 7. The smaller the first dimension d1 of the insulating member 40 along the first direction X, the smaller the coverage area of ​​the insulating member 40 and the higher the difficulty of installation. At the same time, the smaller the extent to which the insulating member 40 extends beyond the electrode body 21 in the first direction X, the smaller the internal space occupied by the insulating member 40 in the battery cell 7.

[0236] The above technical solution sets the first dimension d1 of the insulating member 40 along the first direction X within the above range, thereby reducing the space occupancy of the insulating member 40 while meeting the coverage requirements, thereby improving the energy density of the battery cell 7.

[0237] In some embodiments, a first dimension d1 of the insulating member 40 along the first direction X and a second dimension d2 of the electrode body 21 along the first direction X satisfy the relationship: 5 mm ≤ d1 ≤ d2 + 10 mm. This can further improve the balance between increasing coverage and reducing space occupancy of the insulating member 40.

[0238] As an example, the first dimension d1 of the insulating member 40 along the first direction X can be but is not limited to 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm, 22mm, 24mm, 26mm, 28mm, 35mm, 45mm, 55mm, 65mm, 70mm, etc.

[0239] In some embodiments, a third dimension d3 of the insulating member 40 along the thickness direction Y of the electrode body 21 satisfies the relationship: 0.03 mm≦d3≦1 mm.

[0240] Exemplarily, the third dimension d3 of the insulating member 40 along the thickness direction Y of the electrode body 21 may be understood as the thickness of the insulating member 40 .

[0241] As an example, the third dimension d3 of the insulating member 40 along the thickness direction Y of the electrode body 21 may be, but is not limited to, 0.03 mm, 0.06 mm, 0.08 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.5 mm, 0.8 mm, or 1 mm.

[0242] It is understood that the larger the third dimension d3 of the insulating member 40 along the thickness direction Y of the electrode body 21, the higher the reliability of the insulating member 40, the stronger the insulation protection effect, and the greater the internal space occupied by the insulating member 40 in the battery cell 7. The smaller the third dimension d3 of the insulating member 40 along the thickness direction Y of the electrode body 21, the lower the reliability of the insulating member 40, the weaker the insulation protection effect, and the smaller the internal space occupied by the insulating member 40 in the battery cell 7.

[0243] The above technical solution sets the third dimension d3 of the insulating part 40 along the thickness direction Y of the electrode body 21 within the above range, so that the insulating protection effect of the insulating part 40 meets the requirements while reducing the space occupancy rate of the insulating part 40 to improve the energy density of the battery cell 7.

[0244] In some embodiments, the third dimension d3 of the insulating member 40 along the thickness direction Y satisfies the relationship: 0.05 mm ≤ d3 ≤ 0.2 mm, which can further improve the insulation protection effect of the insulating member 40 and reduce the space occupancy rate.

[0245] As an example, the third dimension d3 of the insulating member 40 along the thickness direction Y of the electrode body 21 can be but is not limited to 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm, 0.16mm, 0.17mm, 0.18mm, 0.19mm, 0.2mm.

[0246] According to some embodiments of the present application, the present application further provides a battery device, comprising a battery cell 7 according to any of the above solutions.

[0247] According to some embodiments of the present application, the present application further provides an electrical device, comprising a battery cell 7 or a battery device according to any of the above schemes, wherein the battery cell 7 or the battery device is used to store or provide electrical energy.

[0248] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution. All technical features and optional technical features of the present application can be combined with each other to form a new technical solution.

[0249] In order to better understand the battery cell 7 provided in the embodiment of the present application, based on the same inventive concept, an embodiment of the above-mentioned battery cell 7 in actual application is provided here for illustration.

[0250] An embodiment of the present application provides a battery cell 7, which includes a housing 10, an electrode unit 20, an insulating film 30, and an insulating member 40. The housing 10 includes a first shell wall 11 and a second shell wall 12 arranged to intersect. The electrode unit 20 is housed within the housing 10 and includes an electrode body 21 and a tab 22. The tab 22 extends from the electrode body 21 toward the first end face 211 of the first shell wall 11. The insulating film 30 is housed within the housing 10 and is used to separate the electrode body 21 from the second shell wall 12. At least a portion of the insulating member 40 is located between the electrode body 21 and the second shell wall 12. The insulating member 40 is attached to at least one of the electrode body 21, the insulating film 30, and the second shell wall 12. The insulating member 40 is disposed at least along the periphery of the first end face 211, and the melting point of the insulating member 40 is greater than the melting point of the insulating film 30.

[0251] The volume energy density of the battery cell 7 is less than or equal to 390Wh / L, and the melting point of the insulating member 40 is greater than or equal to 150°C. Alternatively, the volume energy density of the battery cell 7 is greater than 390Wh / L, and the melting point of the insulating member 40 is greater than or equal to 200°C.

[0252] The above technical solution arranges an insulating member 40 with a relatively high melting point between the electrode body 21 and the second shell wall 12. When the battery cell 7 is heated, the insulating member 40 is not easy to melt. Even if the diaphragm and the insulating film 30 are damaged by heat, the insulating member 40 can still insulate the electrode body 21 and the second shell wall 12, thereby reducing the risk of short circuit caused by overlap between the electrode body 21 and the second shell wall 12, and effectively improving the reliability of the battery cell 7.

[0253] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: The housing comprises a first housing wall and a second housing wall intersecting each other; an electrode unit, housed in the housing, the electrode unit comprising an electrode body and a tab, the tab extending from the electrode body toward the first end surface of the first housing wall; an insulating film, housed in the housing and used to separate the electrode body from the second housing wall; An insulating member, at least a portion of which is located between the electrode body and the second shell wall, and a melting point of the insulating member is greater than a melting point of the insulating film.

2. The battery cell according to claim 1, wherein: The insulating member is attached to at least one of the electrode body, the insulating film, and the second case wall.

3. The battery cell according to claim 1, wherein: The insulating member is provided between the electrode unit and the insulating film, and / or the insulating member is provided between the insulating film and the second shell wall.

4. The battery cell according to claim 1, wherein: The insulating film and the insulating member are an integrally formed structure.

5. The battery cell according to claim 1, characterized in that Along the direction from the electrode body to the first shell wall, the insulating member protrudes from the first end surface; and / or, Along the direction of the first shell wall pointing toward the electrode body, the insulating member protrudes from the second end surface of the electrode body facing away from the first shell wall.

6. The battery cell according to claim 1, characterized in that The insulating member includes a first portion and a second portion, and the first portion and the second portion are respectively arranged on two opposite sides of the electrode body along the thickness direction thereof.

7. The battery cell according to claim 6, characterized in that A projection of the first portion along the thickness direction and a projection of the second portion along the thickness direction at least partially overlap.

8. The battery cell according to claim 6, characterized in that The first portion covers one side surface of the electrode body along the thickness direction; The second portion covers the other side surface of the electrode body in the thickness direction.

9. The battery cell according to claim 1, characterized in that The electrode unit and the first shell wall are arranged along a first direction, and the first direction intersects with a thickness direction of the electrode body; The insulating member is disposed around the electrode body, and a surrounding axis of the insulating member is parallel to the first direction.

10. The battery cell according to claim 9, characterized in that The electrode body further includes an outer peripheral surface connected between the first end surface and a second end surface of the electrode body facing away from the first shell wall, and the insulating member covers the outer peripheral surface.

11. The battery cell according to claim 1, wherein The electrode unit and the first shell wall are arranged along a first direction, and the first direction intersects with a thickness direction of the electrode body; There are multiple insulating parts, including a first insulating part and a second insulating part. At least a portion of the first insulating part is arranged along the outer periphery of the first end surface, and at least a portion of the second insulating part is arranged on the outer periphery of the second end surface of the electrode body facing away from the first shell wall.

12. The battery cell according to claim 11, characterized in that The electrode unit includes at least one electrode assembly, the electrode assembly includes a main body and at least one electrode tab, and the electrode body includes the main body of all the electrode assemblies; The electrode assembly includes a straight area and two bent areas, the two bent areas are connected to two ends of the straight area along the second direction, and the first direction, the second direction and the thickness direction are perpendicular to each other; At least a portion of the insulating member is located between the straight region and the second casing wall.

13. The battery cell according to claim 11, characterized in that The electrode unit includes at least one electrode assembly, the electrode assembly includes a main body and at least one electrode tab, and the electrode body includes the main body of all the electrode assemblies; The electrode assembly includes a plurality of electrode sheets stacked along the thickness direction; The electrode body further includes a third end face and a fourth end face, the third end face and the fourth end face are arranged opposite to each other along the second direction, and the first direction, the second direction and the thickness direction are perpendicular to each other; The insulating member further includes a third insulating member and a fourth insulating member. At least a portion of the third insulating member is disposed along an edge of the third end surface, and at least a portion of the fourth insulating member is disposed along an edge of the fourth end surface.

14. The battery cell according to claim 13, characterized in that The third insulating member is connected between the first insulating member and the second insulating member, and the fourth insulating member is connected between the first insulating member and the second insulating member.

15. The battery cell according to claim 13, characterized in that The first insulating member, the second insulating member, the third insulating member and the fourth insulating member are an integrally formed structure.

16. The battery cell according to any one of claims 1 to 15, characterized in that: The volume energy density of the battery cell is less than or equal to 390Wh / L, and the melting point of the insulating member is greater than or equal to 100°C; or The volume energy density of the battery cell is greater than 390Wh / L, and the melting point of the insulating member is greater than or equal to 150°C.

17. The battery cell according to claim 16, characterized in that The volume energy density of the battery cell is less than or equal to 390Wh / L, and the melting point of the insulating member is greater than or equal to 150°C; or The volume energy density of the battery cell is greater than 390Wh / L, and the melting point of the insulating member is greater than or equal to 200°C.

18. The battery cell according to any one of claims 1 to 15, characterized in that: The electrode unit and the first shell wall are arranged along a first direction, and the first direction intersects with a thickness direction of the electrode body; A first dimension d1 of the insulating member along the first direction and a second dimension d2 of the electrode body along the first direction satisfy the relationship: 3 mm ≤ d1 ≤ d2 + 20 mm.

19. The battery cell according to claim 18, characterized in that A first dimension d1 of the insulating member along the first direction and a second dimension d2 of the electrode body along the first direction satisfy the relationship: 5 mm ≤ d1 ≤ d2 + 10 mm.

20. The battery cell according to any one of claims 1 to 15, characterized in that: A third dimension d3 of the insulating member along the thickness direction of the electrode body satisfies the relationship: 0.03 mm ≤ d3 ≤ 1 mm.

21. The battery cell according to claim 20, characterized in that A third dimension d3 of the insulating member along the thickness direction satisfies the relationship: 0.05 mm ≤ d3 ≤ 0.2 mm.

22. A battery device, characterized in that: The invention comprises a plurality of battery cells according to any one of claims 1 to 21.

23. An electrical device, characterized in that: The battery cell according to any one of claims 1 to 21 or the battery device according to claim 22 is used to store or provide electrical energy.

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