Battery cells, batteries, and power consumption devices

Abstract

This application discloses a battery cell, a battery, and a power consumption device. The battery cell of the embodiment of this application includes a case, electrode terminals, an electrode assembly, and an insulating member. The electrode terminals are mounted in the case. The electrode assembly is housed within the case and includes tabs electrically connected to the electrode terminals. The insulating member connects the electrode terminals to the case and is for insulating and isolating the electrode terminals from the case. The insulating member can not only insulating and isolating the electrode terminals from the case but can also connect the case to the electrode terminals, thereby simultaneously achieving insulation and fixation between the electrode terminals and the case, thereby simplifying the structure of the battery cell and improving the energy density of the battery cell.

Description

Cross-reference of related applications

[0001] This application claims priority to Chinese Patent Application No. 202311145879.4, filed on September 6, 2023, entitled “Battery Cell, Battery and Power Consumption Device,” the entirety of which is incorporated herein by reference. [Technical Field]

[0002] This application relates to the field of batteries, and more particularly to battery cells, batteries, and power consumption devices. [Background technology]

[0003] With advancements in battery technology, battery cells are being applied in an increasing number of fields, and are replacing conventional petrochemical energy in the automotive power sector. Battery cells can store chemical energy and controllably convert it into electrical energy. Recyclable battery cells can be used continuously after discharge by reactivating the active material through charging.

[0004] How to simplify the structure of battery cells is one of the important areas of consideration in the industry. [Overview of the project]

[0005] This application provides a battery cell, a battery, and a power consumption device that can simplify the structure of the battery cell.

[0006] According to a first aspect, the present application provides a battery cell comprising a case, electrode terminals, an electrode assembly, and an insulating member. The electrode terminals are mounted in the case. The electrode assembly is housed within the case and includes tabs electrically connected to the electrode terminals. The insulating member connects the electrode terminals to the case and is for insulating and isolating the electrode terminals from the case.

[0007] The insulating material can not only insulate and isolate the electrode terminals from the case, but also connect the case to the electrode terminals, thereby simultaneously achieving insulation and fixation between the electrode terminals and the case, simplifying the structure of the battery cell and improving the energy density of the battery cell.

[0008] In some embodiments, at least a portion of the insulating member is located between the electrode terminal and the case and is mounted on the electrode terminal and the case.

[0009] The portion of the insulating member located between the case and the electrode terminals can not only insulate and isolate the electrode terminals from the case, but can also be attached to both the case and the electrode terminals, thereby simplifying the electrode terminal mounting and molding processes by insulating and attaching the electrode terminals to the case. When the insulating member is directly connected to the electrode terminals and the case, friction between the insulating member and the electrode terminals and friction between the case and the electrode terminals is reduced when the battery cell is subjected to external impact, thereby reducing the risk of damage and failure of the insulating member and improving reliability.

[0010] In some embodiments, the insulating material is bonded to the case and electrode terminals. The bonding process is simple, facilitating the connection between the insulating material and the case, and between the insulating material and electrode terminals, and reducing the risk of damage to the insulating material during assembly and use.

[0011] In some embodiments, the insulating material is bonded to the case and electrode terminals by a thermocompression bonding composite process.

[0012] The thermocompression bonding composite process is simple, facilitating the connection between the insulating member and the case, and between the insulating member and the electrode terminals. It also improves the adhesion at the composite interface between the insulating member and the case, and between the insulating member and the electrode terminals. This reduces the risk of separation between the insulating member and the case, and between the insulating member and the electrode terminals, when the electrode terminals are subjected to force, thereby improving the reliability of the battery cell.

[0013] In some embodiments, a passivation film connected to an insulating member is provided on a surface of the electrode terminal. Arranging the passivation film can improve the connection strength between the electrode terminal and the insulating member, and improve the corrosion resistance of the electrode terminal.

[0014] In some embodiments, a passivation film connected to an insulating member is provided on a surface of the case. Arranging the passivation film can improve the connection strength between the case and the insulating member, and improve the corrosion resistance of the case.

[0015] In some embodiments, the case includes a wall portion, the wall portion is provided with an electrode lead-out hole, the electrode terminal is arranged on the wall portion, and covers at least a part of the electrode lead-out hole in a thickness direction of the wall portion. The insulating member connects the electrode terminal and the wall portion, and insulates and isolates the electrode terminal from the wall portion.

[0016] In some embodiments, the insulating member is used for sealing the electrode lead-out hole. The insulating member can simultaneously achieve the functions of insulation, sealing and connection between the electrode terminal and the case, thereby simplifying the structure of the battery cell and improving the energy density of the battery cell.

[0017] In some embodiments, the electrode terminal includes a connecting portion, the connecting portion is located on a side along the thickness direction of the wall portion, and a projection of the connecting portion along the thickness direction is located within a projection of the wall portion along the thickness direction. At least a part of the insulating member is located between the wall portion and the connecting portion, and is fitted to the wall portion and the connecting portion.

[0018] The wall portion and the connecting portion are arranged along the thickness direction. During assembly, the wall portion and the connecting portion can apply pressure to the insulating member from both sides, thereby improving the adhesion strength between the wall portion and the insulating member and the adhesion strength between the connecting portion and the insulating member, reducing the risk of separation between the wall portion and the insulating member and the risk of separation between the wall portion and the electrode terminal, and improving the reliability of the battery cell.

[0019] In some embodiments, the projection area along the thickness direction of the portion located between the wall and connection portion of the insulating member is 50 mm². 2 As described above, this increases the connection area between the insulating member and the wall, and between the insulating member and the connection part, thereby improving the stability of the connection between the insulating member, the wall, and the connection part.

[0020] In some embodiments, the projection area along the thickness direction of the portion located between the wall portion and the connection portion of the insulating member is 100 mm². 2 As described above, this further increases the connection area between the insulating member and the wall, and between the insulating member and the connection part, thereby improving the stability of the connection between the insulating member, the wall, and the connection part.

[0021] In some embodiments, the thickness of the portion located between the wall and the connection of the insulating member is between 20 μm and 2000 μm.

[0022] The thickness of the portion of the insulating member located between the wall and the connection is 20 μm or more, thereby increasing the creepage distance between the wall and the connection, reducing the risk of the insulating member tearing when the battery cell is subjected to external impact, improving the insulation effect between the wall and the connection, and reducing the risk of insulation failure. The thickness of the portion of the insulating member located between the wall and the connection is 2000 μm or less, thereby reducing the space and weight occupied by the insulating member, and reducing the loss of energy density in the battery cell.

[0023] In some embodiments, the thickness of the portion located between the wall and the connection of the insulating member is 50 μm to 1000 μm, thereby further improving the balance between the insulating effect of the insulating member and the space occupied by the insulating member.

[0024] In some embodiments, the wall portion includes a first surface and a second surface installed on opposite sides along the thickness direction of the wall portion, the first surface facing the connection portion and the second surface facing away from the connection portion. The insulating member includes a first insulating portion attached to the first surface, at least a portion of which is located between the first surface and the connection portion and covers the portion of the first surface that overlaps with the connection portion in the thickness direction.

[0025] In some embodiments, the first insulating portion protrudes from the connection portion in the radial direction of the electrode extraction hole, thereby increasing the creepage distance between the connection portion and the first surface and improving the insulating effect.

[0026] In some embodiments, both the first insulating portion and the connecting portion are installed surrounding the electrode lead-out hole. The contact surface between the first insulating portion and the connecting portion is annular, and the contact surface between the first insulating portion and the wall portion is also annular. When the battery cell is subjected to an external impact, the annular contact surfaces effectively distribute stress, thereby reducing the risk of connection failure between the first insulating portion and the connecting portion and between the first insulating portion and the wall portion, and improving the reliability of the battery cell. The first insulating portion seals the electrode lead-out hole by surrounding it.

[0027] In some embodiments, the connection is located on the side of the wall facing the electrode assembly. During normal operation of the battery cell, the wall can hold the connection in place, reducing the risk of the electrode terminals becoming detached from the electrode lead-out holes.

[0028] In some embodiments, both the wall portion and the connecting portion are annular. The ratio of the outer diameter D1 of the connecting portion to the outer diameter D2 of the wall portion is 0.3 to 0.8.

[0029] The connection strength of the connection portion, wall portion, and first insulating portion is related to D1 / D2. In the embodiments of this application, D1 / D2 is limited to 0.3 or greater, thereby increasing the effective connection area between the connection portion and the first insulating portion and the effective connection area between the wall portion and the first insulating portion, improving the combined strength between the electrode terminal and the insulating member and the combined strength between the wall portion and the insulating member, reducing the risk of connection failure, improving the reliability of the battery cell, and extending the service life of the battery cell. The larger D1 / D2, the greater the space and weight occupied by the connection portion. In the embodiments of this application, D1 / D2 is limited to 0.8 or less, thereby reducing the loss of energy density and balancing the energy density and reliability of the battery cell.

[0030] In some embodiments, the ratio of the outer diameter D1 of the connection portion to the outer diameter D2 of the wall portion is 0.5 to 0.7.

[0031] In some embodiments, the first surface includes a first region and a second region, the first region being covered by a first insulation, and the second region surrounding the first region. The battery cell further includes an insulating isolation member, where, in the thickness direction, at least a portion of the insulating isolation member is located between the second region and the tab.

[0032] The first insulating portion can isolate the first region from the tab, and the insulating isolation member can isolate at least a portion of the second region from the tab, thereby reducing the risk of the tab coming into contact with the wall when the battery cell is subjected to impact, and improving reliability.

[0033] In some embodiments, the insulating isolation member completely isolates the second region and the tab in the thickness direction, thereby further reducing the risk of short circuits and improving the reliability of the battery cell.

[0034] In some embodiments, the insulating isolation member overlaps with the first insulating portion in the thickness direction, thereby increasing the creepage distance between the tab and the wall portion, reducing the risk of the tab contacting the wall portion when the battery cell is subjected to impact, and improving reliability.

[0035] In some embodiments, the insulating isolation member includes an insulating plate and an insulating tube, the insulating tube surrounding the tab, and the insulating plate connected to the end of the insulating tube facing the first surface and positioned between the first surface and the tab. The insulating plate surrounds the outside of the connection.

[0036] The insulating plate can separate the tabs from the second area, and the insulating tube can bundle the tabs from the outer periphery, thereby reducing the risk of short circuits by separating the tabs from the wall surrounding the tabs of the case. The insulating plate and the connection can improve space utilization by sharing at least some space in the thickness direction.

[0037] In some embodiments, the battery cell further includes a current collector, the current collector located on the side facing the first surface of the tab and connected to the tab, and electrode terminals located on the side away from the tab of the current collector and connected to the current collector. At least a portion of the insulating plate is located between the current collector and the first surface and is mounted on the current collector.

[0038] In some embodiments, the electrode terminals include a terminal body and a first stopper portion that are connected to each other, with at least a portion of the terminal body housed in an electrode exit hole, and the first stopper portion protruding from the outer circumferential surface of the terminal body. The first stopper portion includes a connecting portion. By positioning the terminal body so as to fit into the electrode exit hole, connection between the electrode terminals and other components can be easily achieved. The wall portion prevents the electrode terminals from coming out of the case by receiving the connecting portion.

[0039] In some embodiments, the insulating member further includes a second insulating portion, which is connected to the first insulating portion, surrounds the terminal body, and insulates and isolates the outer surface of the terminal body from the hole wall of the electrode lead hole. The second insulating portion can further insulate and isolate the terminal body from the wall, thereby reducing the risk of electrical conductivity between the terminal body and the case and improving reliability.

[0040] In some embodiments, the second insulating portion is attached to the outer surface of the terminal body and the wall of the electrode lead hole, thereby reducing the risk of external impurities entering the case from between the second insulating portion and the terminal body, and the risk of external impurities entering the electrode lead hole from between the second insulating portion and the wall of the electrode lead hole.

[0041] In some embodiments, the electrode terminal further includes a second stopper portion, which protrudes from the outer circumferential surface of the terminal body and is located on the side away from the electrode assembly of the wall portion. In the thickness direction, at least a portion of the wall portion is located between the connection portion and the second stopper portion.

[0042] The wall portion can be positioned between the first stopper portion and the second stopper portion, thereby restricting relative movement between the electrode terminal and the wall portion. The installation of the second stopper portion increases the connection strength between the electrode terminal and the wall portion, improving stability.

[0043] In some embodiments, the insulating member further includes a third insulating portion connected to a second insulating portion, the third insulating portion being mounted on the second surface, insulating and isolating the second stopper portion from the second surface, thereby reducing the risk of short circuits.

[0044] In some embodiments, the second stopper portion has a bevel facing the second surface. Along the radial direction of the electrode extraction hole, the distance between the bevel and the second surface in the thickness direction gradually increases. At least a portion of the third insulating portion is located between the bevel and the second surface and is mounted on the bevel and the second surface.

[0045] By installing the slope, the space between the second stopper and the second surface is increased, and during the assembly process, when the insulating member is pressed by the second stopper, the material can flow between the second surface and the slope, thereby reducing material overflow.

[0046] In some embodiments, the electrode terminals are provided with slits that extend from the outer circumferential surface of the terminal body and are close to the connection point between the terminal body and the second stopper portion. The slits can distribute stress and reduce stress concentration during the folding molding process of the second stopper portion.

[0047] In some embodiments, the electrode terminal has a first recess on the side away from the electrode assembly, and a second stopper portion is formed by folding the side wall of the first recess outward. A second recess is provided on the outside of the side wall of the first recess, and the second recess is intended to guide the bending of the side wall of the first recess and is configured to be filled after the second stopper portion is formed, thereby forming a slit.

[0048] By creating a first recess, a thin side wall is formed at the electrode terminal. The electrode terminal is attached to the wall by folding back the side wall of the first recess. The second recess can guide the folding of the side wall of the first recess and can also provide space for material flow, thereby reducing material accumulation at the folding position, improving the shape of the electrode terminal, and lowering the difficulty of molding the electrode terminal.

[0049] In some embodiments, the melting point of the first insulating layer is 140°C or higher. The high melting point of the first insulating layer reduces the risk of softening of the first insulating layer during the manufacturing and use of the battery cell, thereby reducing the risk of poor connection between the first insulating layer and the wall, and between the first insulating layer and the connection, and improving reliability.

[0050] In some embodiments, the yield strength of the first insulation layer is 20 MPa or higher, thereby reducing the risk of the first insulation layer being crushed by force during the manufacturing and use of the battery cell, and improving reliability.

[0051] In some embodiments, the first insulating portion includes a first insulating layer, a second insulating layer, and a third insulating layer that are installed in a laminated manner, the first insulating layer being bonded to a first surface, the second insulating layer being located between the first insulating layer and the third insulating layer, and at least a portion of the third insulating layer being bonded to the connection. The first insulating portion uses a multilayer composite structure, which can improve the overall performance of the first insulating portion.

[0052] In some embodiments, the melting point of the second insulating layer is higher than that of the first insulating layer, and the melting point of the second insulating layer is higher than that of the third insulating layer. The second insulating layer has a high melting point and is less likely to soften during the manufacturing and use of the battery cell, thereby insulating and isolating the wall and connection points and reducing the risk of short circuits.

[0053] In some embodiments, the difference between the melting point of the second insulating layer and the melting point of the first insulating layer is 20°C or more, thereby reducing the risk of the second insulating layer softening or melting during the manufacturing and use of the battery cell.

[0054] In some embodiments, the difference between the melting point of the second insulating layer and the melting point of the third insulating layer is 20°C or more, thereby reducing the risk of the second insulating layer softening or melting during the manufacturing and use of the battery cell.

[0055] In some embodiments, the first insulating layer comprises a polymer and a modified polymer, the modified polymer being formed by a modification treatment of the polymer. Both the first and third insulating layers contain the modified polymer, and the second insulating layer contains the polymer.

[0056] By installing a modified polymer, the combined strength between the first insulating layer and the wall portion, and the combined strength between the third insulating layer and the connection portion can be improved, thereby reducing the risk of connection failure between the first insulating layer and the wall portion, and between the third insulating layer and the connection portion.

[0057] In some embodiments, the second insulating layer does not contain a modified polymer, thereby reducing the influence of modification on the polymer's performance and preserving the polymer's inherent properties.

[0058] In some examples, the polymer comprises polypropylene or polyethylene terephthalate.

[0059] In some embodiments, the case includes a case body and an end cover, the case body having an opening, and the end cover fitting over the opening. The case body includes a wall portion installed opposite the end cover.

[0060] According to a second aspect, the present application provides a battery comprising a plurality of battery cells according to any one embodiment of the first aspect.

[0061] According to a third aspect, the present application provides a power consumption device including a battery according to any one embodiment of the second aspect, the battery being for providing electrical energy. [Brief explanation of the drawing]

[0062] The features, advantages, and technical effects of exemplary embodiments of this application will be described below with reference to the drawings.

[0063] [Figure 1] This is a schematic diagram of the structure of a vehicle according to several embodiments of this application. [Figure 2] This is a schematic diagram of a battery exploded according to some embodiments of this application. [Figure 3] Figure 2 is a schematic diagram of the battery module's structure. [Figure 4] This is a schematic diagram of the structure of a battery cell according to several embodiments of this application. [Figure 5] Figure 4 is a schematic diagram of a disassembled battery cell. [Figure 6] Figure 4 is a schematic cross-sectional view of the battery cell. [Figure 7] This is an enlarged schematic diagram of the circular frame in Figure 6. [Figure 8] This is an enlarged schematic view of the corner frame A in Figure 7. [Figure 9] This is an enlarged schematic view of the circular frame B in Figure 7. [Figure 10] These are schematic local cross-sectional views of battery cells according to several embodiments of this application. [Figure 11] These are schematic local cross-sectional views of battery cells according to several embodiments of this application. [Figure 12] This is a schematic diagram of the assembly process of a battery cell according to some embodiments of this application. [Figure 13] This is another schematic diagram of the battery cell assembly process according to some embodiments of this application. [Figure 14] These are schematic local cross-sectional views of battery cells according to several embodiments of this application. [Figure 15] This is an enlarged schematic view of the circular frame in Figure 14. [Figure 16] This is a schematic cross-sectional view of a battery cell according to some other embodiments of this application. [Figure 17] This is an enlarged schematic diagram of the circular frame in Figure 16. [Figure 18] This is a schematic diagram of the structure of a battery cell according to some other embodiments of this application. [Figure 19] This is a schematic cross-sectional view of a battery cell according to some other embodiments of this application. [Explanation of Symbols]

[0064] 1. Vehicle, 2. Battery, 3. Controller, 4. Motor, 5. Housing, 5a. First housing section, 5b. Second housing section, 5c. Enclosure space, 6. Battery module, 7. Battery cell, 10. Electrode assembly, 11. Tab, 12. Main body section, 20, case, 21, case body, 211, side wall, 212, end wall, 22, end cover, 23, wall section, 231, electrode exit hole, 232, first surface, 232a, first region, 232b, second region, 233, second surface, 30, electrode terminal, 31, terminal body, 31a, outer surface, 311, terminal recess, 311a, bottom wall, 312, through hole, 32, first stopper part, 321, connection part, 322, transition part, 33, second stopper part, 331, slope, 34, slit, 35, first recess, 351, side wall of the first recess, 36, second recess, 40, insulating member, 41, first insulating part, 411, first insulating layer, 412, second insulating layer, 413, third insulating layer, 42, second insulating part, 43, third insulating part, 431, fourth insulating layer, 432, fifth insulating layer, 433, sixth insulating layer, 50, insulating isolation member, 51, insulating board, 52, insulating tube, 60, current collector, 70, sealing plate, 80, sealing pin, Z, thickness direction. [Modes for carrying out the invention]

[0065] To further clarify the purpose, technical solutions, and advantages of the embodiments of this application, the technical solutions in the embodiments of this application will be clearly described below with reference to the drawings of the embodiments, and it should be noted that the embodiments described are only some, not all, embodiments of this application. All other embodiments obtained by those skilled in the art without requiring any creative effort based on the embodiments of this application are all within the scope of protection of this application.

[0066] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as those generally understood by those skilled in the art to which this application pertains. The terms used in the application's specification are intended solely to describe specific embodiments and are not intended to limit this application. The terms “includes” and “has” and their synonyms in the specification and claims of this application, as well as in the description of the drawings above, are intended to be non-exclusive. Terms such as “first,” “second,” etc., in the specification and claims of this application or in the drawings above are used to distinguish different subjects and are not used to describe a specific order or hierarchical relationship.

[0067] In this application, the term “Examples” means that certain features, structures, or properties described in relation to the Examples may be included in at least one Example of this Application. Where the term “Examples” appears elsewhere in this Specification, it does not necessarily refer to the same Example, nor does it refer to an Example that is mutually exclusive, independent, or alternative to the other Examples.

[0068] In the description of this application, unless otherwise specifically defined and limited, the terms “attachment,” “connection,” “linking,” and “adhesion” should be understood in a broad sense, for example, a fixed connection, a removable or integral connection, a direct connection, an indirect connection via an intermediate medium, or internal communication between two elements. Those skilled in the art will be able to understand the specific meaning of these terms in this application depending on the specific circumstances.

[0069] In this application, the term "and / or" merely describes the relationship or connection between related objects, indicating that three types of relationships are possible. For example, A and / or B can represent three situations: A existing alone, A and B existing simultaneously, and B existing alone. In this application, the symbol " / " generally indicates that the preceding and succeeding related objects have an "or" relationship.

[0070] In the embodiments of this application, the same reference numerals indicate the same component, and in different embodiments, detailed descriptions of the same component are omitted for brevity. The dimensions such as thickness, length, and width of each component in the embodiments of this application shown in the drawings, and the overall dimensions such as thickness, length, and width of the accumulating device, are for illustrative purposes only and do not limit this application in any way.

[0071] As used in this application, "multiple" refers to two or more (including two).

[0072] In the embodiments of this application, the battery cell may be a secondary battery, which is a battery cell that can continue to be used by activating the active material through a method of charging after the battery cell has discharged.

[0073] Battery cells include, but are not limited to, lithium-ion battery cells, sodium-ion battery cells, sodium-lithium-ion battery cells, lithium metal battery cells, sodium metal battery cells, lithium-sulfur battery cells, magnesium-ion battery cells, nickel-metal hydride battery cells, nickel-cadmium battery cells, and lead-acid battery cells.

[0074] For example, the battery cell may be a cylindrical battery cell, a prismatic battery cell, a soft pack battery cell, or a battery cell of other shape. The prismatic battery cell includes prismatic battery cells, blade-type battery cells, and polygonal prismatic batteries, and the polygonal prismatic battery is, for example, a hexagonal prismatic battery, and is not particularly limited in this application.

[0075] The batteries referred to in the embodiments of this application refer to a single physical module comprising one or more battery cells to provide higher voltage and capacity.

[0076] In some embodiments, the battery may be a battery module, and if there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0077] In some embodiments, the battery may be a battery pack, which includes a housing and battery cells, and the battery cells or battery module are housed within the housing.

[0078] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, part of the housing may be at least part of the vehicle's bottom plate, or part of the housing may be at least part of the vehicle's cross members and side members.

[0079] In some embodiments, the battery may be an energy storage device. The energy storage device includes an energy storage container, an energy storage cabinet, and the like.

[0080] A battery cell generally includes an electrode assembly and a case, with the electrode assembly housed within the case. The electrode assembly includes a positive electrode, a negative electrode, and an isolation member. During the charging and discharging process of the battery cell, active ions (e.g., lithium ions) reciprocate between the positive and negative electrodes, being inserted and removed. The isolation member is placed between the positive and negative electrodes to reduce the risk of short circuits between them while allowing active ions to pass through.

[0081] The case is used to enclose components such as the electrode assembly and electrolyte. The case may be made of steel, aluminum, plastic (e.g., polypropylene), composite metal (e.g., copper-aluminum composite), or aluminum-plastic film.

[0082] Battery cells typically have electrode terminals attached to a case, which are used to electrically connect to an electrode assembly, allowing the electrode assembly to output the electrical energy it generates. To reduce the risk of short circuits, the electrode terminals and the case must be insulated and isolated from each other. The case usually has insulating material, at least a portion of which is located between the electrode terminals and the case, thereby insulating and isolating them.

[0083] In related technologies, the connection structure between electrode terminals, case, and insulating material is complex and affects the manufacturing efficiency and energy density of battery cells.

[0084] In view of this, the embodiment of this application provides a technical solution that connects the electrode terminals and the case via an insulating member, thereby simultaneously achieving insulation and fixation between the electrode terminals and the case, simplifying the structure of the battery cell and improving the energy density of the battery cell.

[0085] The battery cells described in the embodiments of this application are applicable to batteries and power consumption devices that use batteries.

[0086] The battery cells, batteries, and power consumption devices disclosed in the embodiments of this application can be used in power consumption devices that use batteries as a power source or in various energy storage systems that use batteries as energy storage elements. Power consumption devices may include, but are not limited to, mobile phones, tablets, laptop computers, electric toys, power tools, battery cars, electric vehicles, ships, and spacecraft. Electric toys may include stationary or mobile electric toys such as game consoles, electric car toys, electric boat toys, and electric aircraft toys, and spacecraft may include aircraft, rockets, space shuttles, and spacecraft.

[0087] For the sake of explanation, the following embodiments will use a vehicle as an example of a power consumption device.

[0088] Figure 1 is a schematic diagram of the structure of a vehicle according to some embodiments of this application.

[0089] As shown in Figure 1, a battery 2 is installed inside the vehicle 1, and the battery 2 may be installed at the bottom, front, or rear of the vehicle 1. The battery 2 can be used to supply power to the vehicle 1, and can be used, for example, as the operating power source for the vehicle 1.

[0090] Vehicle 1 may further include a controller 3 and a motor 4, the controller 3 being used to control the battery 2 to supply power to the motor 4, for example, to meet the power requirements for starting, navigating, and driving Vehicle 1.

[0091] In some embodiments of this application, the battery 2 can provide driving power to the vehicle 1 not only as an operating power source for the vehicle 1, but also as a driving power source for the vehicle 1, by substituting or partially substituting fuel oil or natural gas.

[0092] Figure 2 is a schematic exploded view of a battery according to some embodiments of this application. As shown in Figure 2, the battery 2 includes a housing 5 and battery cells (not shown in Figure 2), the battery cells being housed within the housing 5.

[0093] The housing 5 is used to house the battery cells, and the housing 5 may have various structures. In some embodiments, the housing 5 may include a first housing portion 5a and a second housing portion 5b, the first housing portion 5a and the second housing portion 5b overlapping each other, and both the first housing portion 5a and the second housing portion 5b define a housing space 5c for housing the battery cells. The second housing portion 5b may be a hollow structure with one end open, and the first housing portion 5a may be a plate-like structure, with the first housing portion 5a overlapping the open side of the second housing portion 5b, thereby forming a housing 5 having a housing space 5c. The first housing portion 5a and the second housing portion 5b may both be hollow structures with one side open, with the open side of the first housing portion 5a overlapping the open side of the second housing portion 5b, thereby forming a housing 5 having a housing space 5c. The first housing portion 5a and the second housing portion 5b may have various shapes such as cylinders and rectangular parallelepipeds.

[0094] To improve the airtightness after connecting the first housing section 5a and the second housing section 5b, sealing members such as sealant and sealing rings may be installed between the first housing section 5a and the second housing section 5b.

[0095] When the first housing section 5a is placed over the upper part of the second housing section 5b, the first housing section 5a can be called the upper housing cover, and the second housing section 5b can be called the lower housing.

[0096] In battery 2, there may be one battery cell or multiple battery cells. If there are multiple battery cells, they can be connected in series, in parallel, or in series-parallel. Series-parallel connection means that there are not only series connections but also parallel connections between the multiple battery cells. Multiple battery cells can be directly connected in series, in parallel, or in series-parallel, and then the entire assembly composed of multiple battery cells can be housed in the housing 5. Naturally, multiple battery cells may first be connected in series, in parallel, or in series-parallel to form a battery module 6, and then the multiple battery modules 6 may be further connected in series, in parallel, or in series-parallel to form a single unit which can then be housed in the housing 5.

[0097] A battery cell may be the smallest unit that makes up a battery.

[0098] Figure 3 is a schematic diagram of the battery module structure shown in Figure 2.

[0099] In some embodiments, as shown in Figure 3, there are multiple battery cells 7, and these multiple battery cells 7 are first connected in series, in parallel, or in series-parallel to form a battery module 6. The multiple battery modules 6 may be further connected in series, in parallel, or in series-parallel to form a single unit and housed in a housing.

[0100] Multiple battery cells 7 in the battery module 6 may be electrically connected by bus members, thereby realizing series connection, parallel connection, or series-parallel connection of multiple battery cells 7 in the battery module 6. There may be one or more bus members, and each bus member is for electrically connecting at least two battery cells.

[0101] Figure 4 is a schematic diagram of the structure of a battery cell according to several embodiments of this application; Figure 5 is an exploded schematic diagram of the battery cell shown in Figure 4; Figure 6 is a schematic cross-sectional diagram of the battery cell shown in Figure 4; Figure 7 is an enlarged schematic diagram of the circular frame in Figure 6; Figure 8 is an enlarged schematic diagram of the rectangular frame A in Figure 7; and Figure 9 is an enlarged schematic diagram of the circular frame B in Figure 7.

[0102] Referring to Figures 4 to 9, an embodiment of the present application provides a battery cell 7 which comprises an electrode assembly 10 and a case 20, the electrode assembly 10 being housed within the case 20.

[0103] The electrode assembly 10 includes a positive electrode and a negative electrode. During the charging and discharging process of the battery cell 7, active ions (e.g., lithium ions) reciprocate between the positive and negative electrodes, being inserted and removed. Selectively, the electrode assembly 10 further includes an isolation member provided between the positive and negative electrodes, which can reduce the risk of short circuits between the positive and negative electrodes while allowing active ions to pass through.

[0104] In some embodiments, the positive electrode is a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material layer provided on at least one surface of the positive electrode current collector.

[0105] For example, the positive electrode current collector has two opposing surfaces in the thickness direction, and the positive electrode active material layer is provided on one or both of the two opposing surfaces of the positive electrode current collector.

[0106] As an example, a metal foil or a composite current collector can be used as the positive electrode current collector. As the metal foil, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, titanium, silver-plated aluminum, stainless steel, or the like can be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (such as aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy) on a polymer material substrate (for example, a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, or the like).

[0107] As an example, the positive electrode active material layer contains a positive electrode active material, and the positive electrode active material may include at least one of lithium-containing phosphates, lithium transition metal oxides, and modified compounds thereof. However, the present application is not limited to these materials, and other conventional materials that can be used as a positive electrode active material layer for batteries may also be used. Only one type of these positive electrode active materials may be used alone, or two or more types may be used in combination. Here, examples of the lithium-containing phosphate include, but are not limited to, at least one of lithium iron phosphate (e.g., LiFePO₄, which may be abbreviated as LFP), composite materials of lithium iron phosphate and carbon, lithium manganese phosphate (e.g., LiMnPO₄), composite materials of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and composite materials of lithium iron manganese phosphate and carbon. Examples of lithium transition metal oxides include lithium cobalt oxide (e.g., LiCoO₂), lithium nickel oxide (e.g., LiNiO₂), lithium manganese oxide (e.g., LiMnO₂, LiMn₂O₄), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (e.g., LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O₂ (NCM 333 which may be abbreviated as), LiNi 0.5 Co 0.2 Mn 0.3 O₂ (NCM523 (It may also be abbreviated as LiNi) 0.5 Co 0.25 Mn 0.25 O2(NCM 211 (It may also be abbreviated as LiNi) 0.6 Co 0.2 Mn 0.2 O2(NCM 622 (It may also be abbreviated as LiNi) 0.8 Co 0.1 Mn 0.1 O2(NCM 811 (May be abbreviated as LiNi) Lithium nickel cobalt aluminum oxide (e.g., LiNi 0.80 Co 0.15 Al 0.05 It may contain, but is not limited to, at least one of O2 and its modified compounds.

[0108] In some embodiments, a foamed metal may be used as the positive electrode. The foamed metal may be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. When a foamed metal is used as the positive electrode, a positive electrode active material layer may or may not be provided on the surface of the foamed metal. As an example, a lithium source material, potassium metal, or sodium metal may be filled and / or deposited within the foamed metal, and the lithium source material is lithium metal and / or a lithium-rich material.

[0109] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0110] As an example, the negative electrode current collector can be a metal foil, foamed metal, or a composite current collector. For example, as the metal foil, silver-plated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium can be used. The foamed metal may be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (such as copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys) on a polymer material base (for example, a base material such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, or polyethylene).

[0111] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material placed on at least one surface of the negative electrode current collector.

[0112] For example, the negative electrode current collector has two opposing surfaces in its thickness direction, and the negative electrode active material is placed on one or both of the two opposing surfaces of the negative electrode current collector.

[0113] For example, the negative electrode active material can be any negative electrode active material well known in the art for battery cells. For example, the negative electrode active material may include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate. The silicon-based material can be selected from at least one of elemental silicon, silicon oxide, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material can be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials usable as negative electrode active materials for batteries may be used. These negative electrode active materials may be used individually or in combination of two or more types.

[0114] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0115] In some embodiments, the isolation member includes a separator. This application does not particularly limit the type of separator, and any known porous structure separator having good chemical and mechanical stability can be selected.

[0116] As an example, the main material of the separator can be selected from at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator may be a single-layer film or a multilayer composite film, and is not particularly limited. If the separator is a multilayer composite film, the materials of each layer may be the same or different, and is not particularly limited. The isolation member may be positioned as a single independent member between the positive and negative electrodes, or it may be attached to the surfaces of the positive and negative electrodes.

[0117] In some embodiments, the isolation member is a solid electrolyte. The solid electrolyte is placed between the positive and negative electrodes and simultaneously performs the roles of ion transport and isolation between the positive and negative electrodes.

[0118] In some embodiments, the case 20 includes a case body 21 and an end cover 22, the case body 21 having an opening, and the end cover 22 being fitted over the opening.

[0119] The housing 21 is an assembly that fits with the end cover 22 to form the internal cavity of the battery cell 7, and the formed internal cavity can be used to house the electrode assembly 10, electrolyte and other components.

[0120] The housing 21 and the end cover 22 may be separate components. For example, an opening may be provided in the housing 21, and the end cover 22 may be placed over the opening to form the internal cavity of the battery cell 7.

[0121] The housing 21 may have various shapes and dimensions, such as a rectangular prism, cylinder, or hexagonal prism. Specifically, the shape of the housing 21 is determined by the specific shape and size of the electrode assembly 10. The material of the housing 21 can be any of several materials, such as copper, iron, aluminum, stainless steel, or aluminum alloy, but is not limited to these.

[0122] The shape of the end cover 22 can be adapted to the shape of the housing 21, allowing it to be fitted into the housing 21. The material of the end cover 22 may be the same as or different from the material of the housing 21. Selectively, the end cover 22 can be manufactured from a material having a certain hardness and strength (e.g., copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.), which makes the end cover 22 less likely to deform even when pressed or struck, allowing the battery cell 7 to have higher structural strength and improved reliability.

[0123] The end cover 22 is connected to the housing 21 by welding, bonding, fastening, or other means.

[0124] The housing 21 may have an open end or both ends. In some examples, the housing 21 may have a structure with one side open, and one end cover 22 is installed and placed over the housing 21. In another example, the housing 21 may have a structure with both sides open, and two end covers 22 are installed, with each of the two end covers 22 placing over the two openings of the housing 21.

[0125] In some embodiments, the battery cell 7 includes electrode terminals 30. The electrode terminals 30 are electrically connected to the electrode assembly 10 and can be used to output or input electrical energy from the battery cell 7.

[0126] In some embodiments, the battery cell 7 includes an electrode assembly 10, a case 20, electrode terminals 30, and an insulating member 40. The electrode terminals 30 are installed in the case 20. The electrode assembly 10 is housed within the case 20 and includes tabs 11 that are electrically connected to the electrode terminals 30. The insulating member 40 connects the electrode terminals 30 to the case 20 and provides insulation and isolation between the electrode terminals 30 and the case 20.

[0127] The electrode assembly 10 is a component in the battery cell 7 that undergoes an electrochemical reaction. The case 20 may contain one or more electrode assemblies 10. The electrode assembly 10 may have a wound structure, a laminated structure, a wound-laminated composite structure, or other structures.

[0128] The shape of the electrode assembly 10 may be cylindrical, flattened, or polygonal prism-shaped, etc.

[0129] As an example, the electrode assembly 10 includes a positive electrode sheet and a negative electrode sheet. The positive electrode sheet includes a positive electrode coated region on which a positive electrode active material layer is applied and a positive electrode uncoated region on which the positive electrode active material layer is not applied, and the negative electrode sheet includes a negative electrode coated region on which a negative electrode active material layer is applied and a negative electrode uncoated region on which the negative electrode active material layer is not applied. The positive electrode uncoated region of the positive electrode sheet constitutes a positive electrode tab, and the negative electrode uncoated region of the negative electrode sheet constitutes a negative electrode tab.

[0130] The tab 11 electrically connected to the electrode terminal 30 may be either a positive electrode tab or a negative electrode tab. During the charging and discharging process of the battery cell 7, the positive electrode active material layer and the negative electrode active material layer react with the electrolyte, and the tab 11 is connected to the electrode terminal 30 to form an electric current circuit.

[0131] The tab 11 may be directly connected to the electrode terminal 30, for example, by welding, contact, or other means. Alternatively, the tab 11 may also be indirectly connected to the electrode terminal 30 via another conductive member (for example, a current collector), thereby achieving an electrical connection between the tab 11 and the electrode terminal 30.

[0132] The case 20 has a hollow structure, and an internal cavity is formed inside it for housing the electrode assembly 10. The shape of the case 20 may be determined according to the specific shape of the electrode assembly 10. For example, if the electrode assembly 10 has a rectangular parallelepiped structure, a rectangular parallelepiped case can be selected, and if the electrode assembly 10 has a cylindrical structure, a cylindrical case can be selected.

[0133] For example, the case 20 includes an end cover 22 and a case body 21, and the electrode terminals 30 may be installed on the case body 21 or on the end cover 22.

[0134] The isolation of the electrode terminals 30 and the case 20 may mean that they are electrically isolated from each other, and that the movement of charge from one to the other is substantially impossible. The insulating member 40 can isolate the case 20 and the electrode terminals 30 by blocking the transport of charge between the case 20 and the electrode terminals 30 to some extent.

[0135] For example, the electrode terminal 30 may be the output terminal of the battery cell 7, which is for electrical connection to the battery's bus component. Selectively, at least a portion of the electrode terminal 30 is exposed to the outside, thereby facilitating connection to the bus component.

[0136] In the embodiment of this application, the insulating member 40 can not only insulate and isolate the electrode terminals 30 from the case 20, but can also connect the case 20 to the electrode terminals 30, thereby simultaneously achieving insulation and fixation between the electrode terminals 30 and the case 20, thereby simplifying the structure of the battery cell 7 and improving the energy density of the battery cell 7.

[0137] In some embodiments, at least a portion of the insulating member 40 is located between the electrode terminal 30 and the case 20 and is attached to the electrode terminal 30 and the case 20.

[0138] The insulating member 40 may be positioned entirely between the case 20 and the electrode terminal 30, or only a portion of it may be positioned between the case 20 and the electrode terminal 30.

[0139] Attachment may also mean being attached and connected, and when one member is attached to another member, the two members are connected at least in part to their contact surfaces, and a fixed connection between the two members is achieved without the need for any other structure. Exemplaryly, one member may be attached to another member by adhesive, coating, or other means.

[0140] The portion of the insulating member 40 located between the case 20 and the electrode terminal 30 can not only insulate and isolate the electrode terminal 30 from the case 20, but can also be attached to both the case 20 and the electrode terminal 30, thereby simplifying the attachment and molding processes of the electrode terminal 30 by insulating and attaching the electrode terminal 30 to the case 20. When the insulating member 40 is directly connected to the electrode terminal 30 and the case 20, if the battery cell 7 is subjected to an external impact, friction between the insulating member 40 and the electrode terminal 30 and friction between the case 20 and the electrode terminal 30 can be reduced, thereby reducing the risk of damage and failure of the insulating member 40 and improving reliability.

[0141] In some embodiments, the insulating member 40 and the case 20 are firmly in contact, and the insulating member 40 and the electrode terminals 30 are firmly in contact. A structure is formed between the insulating member 40 and the case 20 that is firmly in contact, and a structure is formed between the insulating member 40 and the electrode terminals 30 that is firmly in contact, thereby achieving insulation and connection between the case 20 and the electrode terminals 30, and improving the reliability of the battery cell 7.

[0142] In some embodiments, the insulating member 40 is bonded to the case 20 and the electrode terminals 30. The bonding process is simple, facilitating the connection between the insulating member 40 and the case 20 and between the insulating member 40 and the electrode terminals 30, and reducing the risk of damage to the insulating member 40 during assembly and use.

[0143] For example, adhesive bonding can be used to achieve strong adhesion between the insulating member 40 and the case 20, and between the insulating member 40 and the electrode terminal 30.

[0144] In some embodiments, the insulating member 40 is bonded to the case 20 and electrode terminals 30 by a thermocompression bonding composite process.

[0145] The thermocompression bonding composite process is simple, facilitating the connection between the insulating member 40 and the case 20, and between the insulating member 40 and the electrode terminal 30. It also improves the adhesion force at the composite interface between the insulating member 40 and the case 20, and between the insulating member 40 and the electrode terminal 30. This reduces the risk of separation between the insulating member 40 and the case 20, and between the insulating member 40 and the electrode terminal 30, when the electrode terminal 30 is subjected to force, thereby improving the reliability of the battery cell 7.

[0146] In some embodiments, the insulating member 40 is firmly attached to the case 20 via a micro-fitting structure, and the insulating member 40 is firmly attached to the electrode terminal 30 via a micro-fitting structure.

[0147] The micro-fitting structure achieves a strong bond and simplifies the operation process. It also improves the adhesion force at the composite interface between the insulating member 40 and the case 20, and at the composite interface between the insulating member 40 and the electrode terminal 30. This reduces the risk of separation between the insulating member 40 and the case 20, and the risk of separation between the insulating member 40 and the electrode terminal 30 when the electrode terminal 30 is subjected to force, thereby improving the reliability of the battery cell 7.

[0148] In some embodiments, a passivation film connected to an insulating member 40 is provided on the surface of the electrode terminal 30.

[0149] By installing a passivation film, a porous structure can be formed on the electrode terminal 30, thereby increasing the specific surface area of ​​the electrode terminal 30, enhancing adsorption of the electrode terminal 30 to the insulating member 40, improving the mechanical engagement between the electrode terminal 30 and the insulating member 40, and simultaneously, the formation of hydrogen bonds in the passivation film of the electrode terminal 30 firmly adheres the electrode terminal 30 and the insulating member 40, thereby improving the connection strength between the electrode terminal 30 and the insulating member 40.

[0150] The passivation film can also improve the corrosion resistance of the electrode terminals 30.

[0151] For example, the electrode terminal 30 can be subjected to a passivation treatment, thereby forming a passivation film on the surface of the electrode terminal 30.

[0152] In some embodiments, the thickness of the passivation film on the electrode terminal 30 is 0.01 μm to 1 μm.

[0153] In some embodiments, a passivation film connected to the insulating member 40 is provided on the surface of the case 20.

[0154] The placement of the passivation film allows for the formation of a porous structure in the case 20, thereby increasing the specific surface area of ​​the case 20, enhancing adsorption of the case 20 to the insulating member 40, improving the mechanical interlocking between the case 20 and the insulating member 40, and simultaneously, the formation of hydrogen bonds in the passivation film of the case 20, which firmly adheres the case 20 and the insulating member 40, improving the connection strength between the case 20 and the insulating member 40. The passivation film can also improve the corrosion resistance of the case 20.

[0155] In some examples, the thickness of the passivation film in case 20 is 0.01 μm to 1 μm.

[0156] In some embodiments, the material of the insulating member 40 may include a thermal composite adhesive.

[0157] In some embodiments, both the case 20 and the electrode terminals 30 are made of metal.

[0158] In some embodiments, the electrode terminals 30, the case 20, and the thermal bonding adhesive are heated and pressurized, thereby bonding the thermal bonding adhesive to the electrode terminals 30 and the case 20.

[0159] The passivation film contains many polar groups, which can enhance hydrogen bonding between the metal surface and the thermal bonding adhesive, thereby improving the interfacial composite strength. The purpose of heating and pressurizing is to melt the thermal bonding adhesive, allowing it to penetrate the microporous structure of the metal surface, and to react better with the polar functional groups on the metal surface to form bonds.

[0160] The passivation film has a large number of polar groups or a porous structure, and is intended to improve the adhesive strength between the metal surface and the thermal composite adhesive, as well as the corrosion resistance of the metal material, thereby extending the service life of the battery cell 7.

[0161] The insulating member 40 can provide insulation and connection between the two metal interfaces.

[0162] In some embodiments, the case 20 includes a wall portion 23, the wall portion 23 is provided with an electrode exit hole 231, and the electrode terminal 30 is installed in the wall portion 23 and covers at least a portion of the electrode exit hole 231 in the thickness direction Z of the wall portion 23. The insulating member 40 connects the electrode terminal 30 and the wall portion 23 and insulates and isolates the electrode terminal 30 and the wall portion 23.

[0163] For example, the wall portion 23 may be an end cover 22, or it may be one of the walls of the case body 21.

[0164] For example, the shape of the wall portion 23 may be circular, rectangular, elliptical, or other shapes.

[0165] Exemplary, the electrode exit hole 231 penetrates the wall 23, thereby facilitating the electrode terminal 30 to draw electrical energy from the electrode assembly 10 to the outside of the case 20. Selectively, the electrode exit hole 231 penetrates the wall 23 along the thickness direction Z of the wall 23.

[0166] The electrode terminal 30 may cover only a portion of the electrode exit hole 231, or it may completely cover the electrode exit hole 231. For example, the electrode terminal 30 alone can seal the electrode exit hole 231, isolating the internal space of the case 20 from the external space and improving the sealing performance of the battery cell 7. Alternatively, the electrode terminal 30 can also be combined with other functional members (e.g., an insulating member 40) to jointly seal the electrode exit hole 231, thereby isolating the internal space of the case 20 from the external space and improving the sealing performance of the battery cell 7.

[0167] In some embodiments, the case 20 includes a case body 21 and an end cover 22, the case body 21 having an opening, and the end cover 22 is fitted over the opening.

[0168] Selectively, the case body 21 includes a side wall 211 and an end wall 212, the side wall 211 surrounding the outside of the electrode assembly 10, the end wall 212 positioned opposite the opening, and the wall portion 23 is either an end cover 22 or an end wall 212.

[0169] The side walls 211 may be one or more. In some examples, the side walls 211 may be one and have a cylindrical structure. In some other examples, the side walls 211 may be multiple and connected sequentially along the circumferential direction of the electrode assembly 10, for example, there may be four side walls 211, which are connected sequentially to form a rectangular tube structure.

[0170] In some embodiments, the battery cell 7 is a cylindrical battery cell, with a single side wall 211, exhibiting a cylindrical structure. Since the end cover 22 or end wall 212 is flatter than the side wall 211, the assembly efficiency of the battery cell 7 can be improved by placing the electrode terminals 30 on the end cover 22 or end wall 212.

[0171] In some embodiments, the case body 21 includes a wall portion 23 that is installed opposite the end cover 22. Exemplarily, the wall portion 23 is the end wall 212 of the case body 21.

[0172] In some embodiments, the insulating member 40 is for sealing the electrode lead-out hole 231.

[0173] Sealing the electrode exit hole 231 may also mean separating the internal space of the case 20 from the external space of the case 20 by cutting off communication between the electrode exit hole 231 and the internal space of the case 20, and / or cutting off communication between the electrode exit hole 231 and the external space of the case 20.

[0174] The insulating member 40 can simultaneously perform the functions of insulating, sealing, and connecting the electrode terminals 30 and the case 20, thereby simplifying the structure of the battery cell 7 and improving the energy density of the battery cell 7.

[0175] The insulating member 40 is attached to the electrode terminal 30 and the case 20, reducing the risk of external impurities entering the case 20 from between the insulating member 40 and the electrode terminal 30, and reducing the risk of external impurities entering the case 20 from between the insulating member 40 and the case 20, thereby improving sealing performance.

[0176] In some embodiments, the insulating member 40 connects the electrode terminals 30 and the case 20, providing insulation and sealing functions, and can also reduce the dimensions of the electrode terminals 30 in the thickness direction Z, thereby improving the energy density of the battery cell 7.

[0177] In some embodiments, at least a portion of the insulating member 40 is located between the wall portion 23 and the electrode terminal 30 in the thickness direction Z, and surrounds the electrode exit hole 231.

[0178] In some embodiments, the electrode terminal 30 includes a connecting portion 321, the connecting portion 321 is located on the side of the wall portion 23 along the thickness direction Z, and the projection of the connecting portion 321 along the thickness direction Z is located within the projection of the wall portion 23 along the thickness direction Z. At least a portion of the insulating member 40 is located between the wall portion 23 and the connecting portion 321 and is attached to the wall portion 23 and the connecting portion 321.

[0179] The connecting portion 321 may be located on the side of the wall portion 23 facing the electrode assembly 10, or it may be located on the side of the wall portion 23 away from the electrode assembly 10.

[0180] The connection portion 321 may be one or more. In some examples, the connection portion 321 is one and annular, and in some other examples, the connection portion 321 is multiple, and the multiple connection portions 321 are spaced apart along the circumferential direction of the electrode lead-out hole 231.

[0181] In the thickness direction Z of the wall portion 23, the projection of the connection portion 321 and the projection of the electrode extraction hole 231 do not overlap.

[0182] In the thickness direction Z of the wall portion 23, the insulating member 40 may be located entirely between the wall portion 23 and the connection portion 321, or only a portion of it may be located between the wall portion 23 and the connection portion 321.

[0183] The wall portion 23 and the connecting portion 321 are installed along the thickness direction Z, and during assembly, the wall portion 23 and the connecting portion 321 can apply pressure to the insulating member 40 from both sides, thereby improving the adhesion strength between the wall portion 23 and the insulating member 40 and between the connecting portion 321 and the insulating member 40, reducing the risk of separation between the wall portion 23 and the insulating member 40 and the risk of separation between the wall portion 23 and the electrode terminal 30, and improving the reliability of the battery cell 7.

[0184] In some embodiments, the connecting portion 321 protrudes beyond the wall of the electrode extraction hole 231 along the radial direction of the electrode extraction hole 231. The radial direction of the electrode extraction hole 231 may pass through the central axis of the electrode extraction hole 231 and be perpendicular to the central axis of the electrode extraction hole 231. Selectively, the central axis of the electrode extraction hole 231 is parallel to the thickness direction Z of the wall portion 23.

[0185] The central axis of the electrode extraction hole 231 may be a single imaginary line. For example, the electrode extraction hole 231 is rotationally symmetric with respect to the central axis.

[0186] In some examples, the electrode extraction hole 231 may be a circular hole, and the radial direction of the electrode extraction hole 231 may be the radial direction of the electrode extraction hole 231. In some other examples, the electrode extraction hole 231 may be a square hole, and the radial direction of the electrode extraction hole 231 may be the radial direction of the circumscribed circle of the electrode extraction hole 231.

[0187] In some embodiments, the projection area S along the thickness direction Z of the portion of the insulating member 40 located between the wall portion 23 and the connection portion 321 is 50 mm 2 That's all.

[0188] In the embodiment of this application, the connection area between the insulating member 40 and the wall portion 23 is 50 mm². 2 The above is achieved by setting the connection area between the insulating member 40 and the connection part 321 to 50 mm². 2 By doing so, the stability of the connection between the insulating member 40, the wall portion 23, and the connecting portion 321 can be improved.

[0189] For example, the portion of the insulating member 40 located between the wall portion 23 and the connecting portion 321 is annular, and the inner diameter r of the annular portion may be the diameter of the electrode extraction hole 231, and the outer diameter of the annular portion may be the outer diameter R of the connecting portion 321. S = π × (R 2 -r 2 ).

[0190] In some embodiments, S is 50 mm2 , 80mm 2 , 100mm 2 , 120mm 2 , 150mm 2 , 170mm 2 , 180mm 2 Or 200mm 2 That is the case.

[0191] In some embodiments, S is 100 mm or more.

[0192] In some embodiments, the surface of the connection portion 321 that is connected to the insulating member 40 is flat.

[0193] In some embodiments, the connecting portion 321 is annular.

[0194] In some embodiments, the thickness of the portion of the insulating member 40 located between the wall portion 23 and the connection portion 321 is between 20 μm and 2000 μm.

[0195] The thickness of the portion of the insulating member 40 located between the wall portion 23 and the connection portion 321 is 20 μm or more, thereby increasing the creepage distance between the wall portion 23 and the connection portion 321, reducing the risk of the insulating member 40 tearing when the battery cell 7 is subjected to external impact, improving the insulation effect between the wall portion 23 and the connection portion 321, and reducing the risk of insulation failure. The thickness of the portion of the insulating member 40 located between the wall portion 23 and the connection portion 321 is 2000 μm or less, thereby reducing the space and weight occupied by the insulating member 40, and reducing the loss of energy density of the battery cell 7.

[0196] Selectively, the thickness of the portion of the insulating member 40 located between the wall portion 23 and the connection portion 321 is 20 μm, 30 μm, 50 μm, 100 μm, 150 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, 1000 μm, 1200 μm, 1400 μm, 1500 μm, 1800 μm, or 2000 μm.

[0197] For example, the total thickness of the wall portion 23, the connecting portion 321, and the portion of the insulating member 40 located between the wall portion 23 and the connecting portion 321 can be measured first. Then, the thickness of the connecting portion 321 and the thickness of the wall portion 23 can be measured, and the thickness at one spot of the insulating member 40 can be calculated. Using this method, the thickness at 10 spots of the insulating member 40 was measured, and the average thickness was calculated. This average thickness may be the thickness of the portion of the insulating member 40 located between the wall portion 23 and the connecting portion 321.

[0198] In some embodiments, the thickness of the portion of the insulating member 40 located between the wall portion 23 and the connection portion 321 is 50 μm to 1000 μm.

[0199] In some embodiments, the thickness of the portion of the insulating member 40 located between the wall portion 23 and the connection portion 321 is 100 μm to 500 μm.

[0200] In some embodiments, the breakdown voltage of the insulating member 40 is 500V or higher.

[0201] In some embodiments, the wall portion 23 includes a first surface 232 and a second surface 233 that are installed on opposite sides along the thickness direction Z of the wall portion 23, the first surface 232 facing the connection portion 321 and the second surface 233 facing away from the connection portion 321.

[0202] For example, the first surface 232 may be an inner surface facing the electrode assembly 10 of the wall portion 23, and the second surface 233 may be an outer surface facing away from the electrode assembly 10 of the wall portion 23. Alternatively, the second surface 233 may be an inner surface facing the electrode assembly 10 of the wall portion 23, and the first surface 232 may be an outer surface facing away from the electrode assembly 10 of the wall portion 23.

[0203] In some embodiments, the insulating member 40 includes a first insulating portion 41 mounted on the first surface 232, at least a portion of which is located between the first surface 232 and the connecting portion 321 and covers the region of the first surface 232 that overlaps with the connecting portion 321 in the thickness direction Z.

[0204] In the thickness direction Z, the entire first insulating portion 41 may be located between the first surface 232 and the connecting portion 321, or only a portion of it may be located between the first surface 232 and the connecting portion 321.

[0205] For example, the first insulating portion 41 is attached to both the wall portion 23 and the connection portion 321, so that the electrode terminal 30 can be insulated and mounted to the case 20. Because the first insulating portion 41 is directly attached to the wall portion 23 and the connection portion 321, the embodiment of this application has less compression requirement for the first insulating portion 41, that is, it is possible to improve the sealing performance of the connection interface between the first insulating portion 41 and the wall portion 23 and the connection interface between the first insulating portion 41 and the connection portion 321, while reducing the pressure on the first insulating portion 41 and reducing the risk of damage to the first insulating portion 41.

[0206] In some embodiments, the thickness of the first insulating portion 41 is 50 μm to 1000 μm.

[0207] In some embodiments, the first insulating portion 41 protrudes from the connecting portion 321 in the radial direction of the electrode extraction hole 231, thereby increasing the creepage distance between the connecting portion 321 and the first surface 232 and improving the insulating effect.

[0208] Selectively, the thickness of the first insulating portion 41 is 50 μm, 100 μm, 150 μm, 250 μm, 350 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, or 1000 μm.

[0209] In some embodiments, both the first insulating portion 41 and the connecting portion 321 are installed surrounding the electrode lead-out hole 231.

[0210] The contact surface between the first insulating portion 41 and the connecting portion 321 is annular, and the contact surface between the first insulating portion 41 and the wall portion 23 is also annular. When the battery cell 7 is subjected to an external impact, the annular contact surfaces effectively distribute stress, thereby reducing the risk of connection failure between the first insulating portion 41 and the connecting portion 321 and the risk of connection failure between the first insulating portion 41 and the wall portion 23, and improving the reliability of the battery cell 7. The first insulating portion 41 seals the electrode lead-out hole 231 by surrounding it.

[0211] In some embodiments, the connecting portion 321 is located on the side of the wall portion 23 that faces the electrode assembly 10.

[0212] During the normal operation of the battery cell 7, the wall portion 23 can stop the connection portion 321, reducing the risk of the electrode terminal 30 detaching from the electrode lead-out hole 231.

[0213] In some embodiments, both the wall portion 23 and the connecting portion 321 are annular in shape.

[0214] In some embodiments, the battery cell 7 is a cylindrical battery cell.

[0215] In some embodiments, the ratio of the outer diameter D1 of the connecting portion 321 to the outer diameter D2 of the wall portion 23 is 0.3 to 0.8.

[0216] The connection strength of the three components, the connection portion 321, the wall portion 23, and the first insulating portion 41, is related to D1 / D2. In the embodiment of this application, D1 / D2 is limited to 0.3 or greater. This increases the effective connection area between the connection portion 321 and the first insulating portion 41, and between the wall portion 23 and the first insulating portion 41. This improves the combined strength between the electrode terminal 30 and the insulating member 40, and between the wall portion 23 and the insulating member 40, thereby reducing the risk of connection failure, improving the reliability of the battery cell 7, and extending the service life of the battery cell 7.

[0217] The larger D1 / D2 is, the greater the space and weight occupied by the connection portion 321. In the embodiment of this application, D1 / D2 is limited to 0.8 or less, thereby reducing energy density loss and balancing the energy density and reliability of the battery cell 7.

[0218] For example, D1 / D2 can be 0.3, 0.4, 0.5, 0.6, 0.7, or 0.8.

[0219] For example, the outer diameter D2 of the wall portion 23 is the diameter of the cylindrical case.

[0220] In some embodiments, D1 / D2 is between 0.5 and 0.7.

[0221] In some embodiments, the first surface 232 includes a first region 232a and a second region 232b, the first region 232a being covered by a first insulating portion 41, and the second region 232b surrounding the first region 232a. The battery cell 7 further includes an insulating isolation member 50, where at least a portion of the insulating isolation member 50 is located between the second region 232b and the tab 11 in the thickness direction Z.

[0222] The first insulating portion 41 can insulate and isolate the first region 232a from the tab 11, and the insulating isolation member 50 can isolate at least a portion of the second region 232b from the tab 11, thereby reducing the risk of the tab 11 coming into contact with the wall portion 23 when the battery cell 7 is subjected to impact, and improving reliability.

[0223] In some embodiments, the insulating isolation member 50 completely isolates the second region 232b and the tab 11 in the thickness direction Z, thereby further reducing the risk of short circuits and improving the reliability of the battery cell 7.

[0224] In some embodiments, the insulating isolation member 50 overlaps with the first insulating portion 41 in the thickness direction Z.

[0225] The embodiment of this application increases the creepage distance between the tab 11 and the wall portion 23, thereby reducing the risk of the tab 11 coming into contact with the wall portion 23 when the battery cell 7 is subjected to an impact, and improving reliability.

[0226] In some embodiments, the overlapping portion of the insulating isolation member 50 and the first insulating portion 41 in the thickness direction Z is annular, and the width of the ring of the overlapping portion is 1 mm or more.

[0227] In some embodiments, the insulating isolation member 50 includes an insulating plate 51 and an insulating cylinder 52, the insulating cylinder 52 surrounding the tab 11, and the insulating plate 51 connected to the end of the insulating cylinder 52 facing the first surface 232 and positioned between the first surface 232 and the tab 11. The insulating plate 51 surrounds the outside of the connection portion 321.

[0228] The insulating plate 51 can separate the tab 11 from the second region 232b, and the insulating cylinder 52 can bundle the tab 11 from the outer circumference, thereby reducing the risk of short circuits by separating the wall surrounding the tab 11 of the case 20 from the tab 11. The insulating plate 51 and the connection portion 321 can improve space utilization by sharing at least a portion of the space in the thickness direction Z.

[0229] In some embodiments, the electrode assembly 10 includes a body portion 12, and the tab 11 is drawn out from an end of the body portion 12 facing a wall portion 23. Exemplarily, the body portion 12 includes a positive electrode coating area, a negative electrode coating area, and an isolation member.

[0230] In some embodiments, the insulating tube 52 further surrounds the end of the main body 12 closest to the tab 11.

[0231] In some embodiments, the insulating cylinder 52 is connected to the main body 12.

[0232] In some embodiments, the insulating tube 52 is bonded to the main body 12. Exemplarily, the insulating isolation member 50 is insulating tape.

[0233] In some embodiments, the insulating isolation member 50 is a heat-shrinkable tube.

[0234] In some embodiments, the battery cell 7 further includes a current collector 60, the current collector 60 located on the side facing the first surface 232 of the tab 11 and connected to the tab 11, and the electrode terminals 30 located on the side away from the tab 11 of the current collector 60 and connected to the current collector 60.

[0235] The current collector 60 acts as a relay, facilitating the electrical connection between the electrode terminal 30 and the tab 11.

[0236] In some embodiments, the current collector 60 protrudes from the connection portion 321 in the radial direction of the electrode lead-out hole 231. The current collector 60 is connected to the outer portion of the tab 11, which can reduce differences in the conductive path between different parts of the tab 11 and the electrode terminal 30 and improve consistency.

[0237] In some embodiments, at least a portion of the insulating plate 51 is located between the current collector 60 and the first surface 232 and is attached to the current collector 60.

[0238] The insulating plate 51 can insulate and isolate the current collector 60 from the wall portion 23, thereby reducing the risk of short circuits. The current collector 60 fixes the insulating plate 51, reduces the oscillation of the insulating isolation member 50 when the battery cell 7 is subjected to impact, and reduces the risk of electrical contact between the current collector 60 and the wall portion 23.

[0239] In some embodiments, the insulating plate 51 covers the region of the current collector member 60 that overlaps with the second region 232b in the thickness direction Z.

[0240] In some embodiments, the electrode terminal 30 presses against the tab 11 via the current collector 60. Selectively, D1 / D2 is 0.5 or greater, and the electrode terminal 30 can support a large area of ​​the tab 11 via the current collector 60, and during the case insertion process of the electrode assembly 10, the electrode terminal 30 can effectively support the tab 11 via the current collector 60, reducing misalignment between the positive and negative electrode sheets of the electrode assembly 10.

[0241] In some embodiments, the electrode terminal 30 includes a terminal body 31 and a first stopper portion 32 that are connected to each other, with at least a portion of the terminal body 31 housed in an electrode lead-out hole 231, and the first stopper portion 32 protruding from the outer peripheral surface 31a of the terminal body 31. The first stopper portion 32 includes a connecting portion 321.

[0242] The first stopper portion 32 may include only the connecting portion 321, or it may further include other parts other than the connecting portion 321.

[0243] The first stopper portion 32 may be one or multiple. Selectively, the first stopper portion 32 may be one, and the first stopper portion 32 may have a ring structure.

[0244] The terminal body 31 may be entirely located within the electrode lead-out hole 231, or only a portion of it may be located within the electrode lead-out hole 231.

[0245] By positioning the terminal body 31 so that it fits into the electrode exit hole 231, the electrode terminal 30 can be easily connected to other components. The wall portion 23 prevents the electrode terminal 30 from coming out of the case 20 by receiving the connection portion 321.

[0246] For example, the terminal body 31 has a columnar structure, and the first stopper portion 32 has an annular structure that surrounds the outside of the terminal body 31.

[0247] In some embodiments, the first stopper portion 32 includes a connecting portion 321 and a transition portion 322, the transition portion 322 connecting the terminal body 31 and the connecting portion 321. In the thickness direction Z of the wall portion 23, the projection of the transition portion 322 is located within the projection of the electrode extraction hole 231.

[0248] For example, in the thickness direction Z, the boundary position between the connection portion 321 and the transition portion 322 corresponds to the hole wall of the electrode extraction hole 231. For instance, as shown in Figure 8, the boundary position between the connection portion 321 and the transition portion 322 is indicated by a dotted line, which is for ease of understanding and does not actually exist at the electrode terminal.

[0249] In some embodiments, the thickness of the first insulating portion 41 is 1 mm or less, and by reducing the requirements for the dimensions of the terminal body 31, the energy density can be improved.

[0250] In some embodiments, the insulating member 40 further includes a second insulating portion 42, which is connected to the first insulating portion 41, surrounds the terminal body 31, and insulates and isolates the outer peripheral surface 31a of the terminal body 31 from the hole wall of the electrode lead-out hole 231.

[0251] The second insulating portion 42 may be entirely located within the electrode exit hole 231, or only a portion of it may be located within the electrode exit hole 231. For example, the end of the second insulating portion 42 along the axial direction of the electrode exit hole 231 may extend outside the electrode exit hole 231.

[0252] For example, the second insulating portion 42 is a cylindrical structure that surrounds the outside of the terminal body 31.

[0253] The second insulating section 42 can insulate and isolate the terminal body 31 from the wall section 23, thereby reducing the risk of electrical conductivity between the terminal body 31 and the case 20 and improving reliability.

[0254] In some embodiments, the second insulating portion 42 is attached to the outer circumferential surface 31a of the terminal body 31. The terminal body 31 can fix the second insulating portion 42, reducing the risk of the second insulating portion 42 falling off. The second insulating portion 42 is attached to the terminal body 31, thus reducing the risk of external impurities entering the case 20 from between the second insulating portion 42 and the terminal body 31.

[0255] In some embodiments, the second insulating portion 42 is attached to the wall of the electrode extraction hole 231. The wall of the electrode extraction hole 231 can fix the second insulating portion 42 in place, reducing the risk of the second insulating portion 42 falling off. The second insulating portion 42 is attached to the wall of the electrode extraction hole 231, thus reducing the risk of external impurities entering the electrode extraction hole 231 from between the second insulating portion 42 and the wall of the electrode extraction hole 231.

[0256] In some embodiments, the first insulating portion 41 is connected to the second insulating portion 42, thereby reducing the gap between the first insulating portion 41 and the second insulating portion 42, further improving insulation performance and reducing the risk of electrical contact between the wall portion 23 and the electrode terminal 30.

[0257] In some embodiments, the electrode terminal 30 further includes a second stopper portion 33, the second stopper portion 33 protruding from the outer peripheral surface 31a of the terminal body 31 and located on the side of the wall portion 23 away from the electrode assembly 10. In the thickness direction Z, at least a portion of the wall portion 23 is located between the connecting portion 321 and the second stopper portion 33.

[0258] The wall portion 23 can be positioned between the first stopper portion 32 and the second stopper portion 33, thereby restricting relative movement between the electrode terminal 30 and the wall portion 23. The installation of the second stopper portion 33 increases the connection strength between the electrode terminal 30 and the wall portion 23, improving stability.

[0259] In some embodiments, the insulating member 40 further includes a third insulating portion 43 connected to a second insulating portion 42, the third insulating portion 43 being mounted on a second surface 233, insulating and isolating the second stopper portion 33 from the second surface 233, thereby reducing the risk of short circuits.

[0260] In some embodiments, the entire third insulating portion 43 may be located between the second stopper portion 33 and the case 20, or only a portion of it may be located between the second stopper portion 33 and the case 20.

[0261] In some embodiments, the third insulating portion 43 is mounted on the second surface 233, thereby improving the sealing performance of the connection surface between the third insulating portion 43 and the wall portion 23.

[0262] In some embodiments, the third insulating portion 43 is connected to the second insulating portion 42, thereby reducing the gap between the third insulating portion 43 and the second insulating portion 42, improving insulation performance and reducing the risk of electrical contact between the wall portion 23 and the electrode terminal 30.

[0263] In some embodiments, in the radial direction of the electrode lead-out hole 231, the end of the first stopper portion 32 away from the terminal body 31 protrudes more than the end of the second stopper portion 33 away from the terminal body 31.

[0264] In the radial direction of the electrode lead-out hole 231, the first stopper portion 32 is larger in dimensions than the second stopper portion 33. In this way, the connection area between the connecting portion 321 and the first insulating portion 41, and the connection area between the wall portion 23 and the first insulating portion 41 are increased, thereby strengthening the connection strength of the wall portion 23, the first insulating portion 41, and the connecting portion 321, and reducing the risk of connection failure.

[0265] In some embodiments, the connection strength between the second stopper portion 33 and the third insulating portion 43 is lower than the connection strength between the first insulating portion 41 and the connecting portion 321.

[0266] Illustratively, under the same conditions, the force required to peel the first insulating portion 41 from the connecting portion 321 is larger than the force required to peel the third insulating portion 43 from the second stopper portion 33.

[0267] The connection strength between the first insulating portion 41 and the connecting portion 321 is high, and the first insulating portion 41 can achieve effective sealing effect and effective connecting effect. The embodiments of the present application can simplify the process by reducing the requirement for the connection strength between the second stopper portion 33 and the third insulating portion 43.

[0268] The surface of the connecting portion 321 facing the first surface 232 is flatter than the surface of the second stopper portion 33 facing the second surface 233, thereby improving the connection strength between the first insulating portion 41 and the connecting portion 321.

[0269] In some embodiments, the electrode terminal 30 forms the second stopper portion 33 by a drawing process, so as to rivet the electrode terminal 30 to the wall portion 23.

[0270] In some embodiments, the first stopper portion 32, the second stopper portion 33 and the terminal body 31 are of an integrally formed structure. The embodiments of the present application can improve the overall structural strength of the electrode terminal 30, reduce the internal resistance of the electrode terminal 30, and improve the current passing capability.

[0271] In some embodiments, the melting point of the first insulating portion 41 is 140°C or higher. The melting point refers to the melting point under normal pressure.

[0272] The first insulating portion 41 has a high melting point, thereby reducing the risk of softening of the first insulating portion 41 during the manufacturing and use of the battery cell 7, so as to reduce the risk of poor connection between the first insulating portion 41 and the wall portion 23 and the risk of poor connection between the first insulating portion 41 and the connecting portion 321, and improve reliability.

[0273] In some embodiments, the yield strength of the first insulating portion 41 is 20 MPa or higher, thereby reducing the risk of the first insulating portion 41 being crushed by force during the manufacturing and use of the battery cell 7, and improving reliability.

[0274] In some embodiments, the melting point of the insulating member 40 is 140°C or higher.

[0275] In some embodiments, the yield strength of the insulating member 40 is 20 MPa or higher.

[0276] In some embodiments, a terminal recess 311 is provided on the outside of the terminal body 31, and the bottom wall 311a of the terminal recess 311 is welded to the current collector 60.

[0277] In this embodiment, the terminal body 31 and the current collector 60 can be welded from the outside, thereby reducing the risk of metal particles generated by welding scattering into the case 20 and improving reliability. In this embodiment, the thickness of the terminal body 31 can be reduced by providing a terminal recess 311, thereby reducing the welding power required to weld the terminal body 31 and the current collector 60, reducing heat generation, and reducing the risk of thermal damage to the insulating member 40.

[0278] In some embodiments, the terminal recess 311 is formed in the terminal body 31.

[0279] In some embodiments, a through hole 312 is provided in the bottom wall 311a of the terminal recess 311. The through hole 312 is for communicating the terminal recess 311 with the internal space of the case 20.

[0280] In the manufacturing process of the battery cell 7, the through-hole 312 can be used in multiple manufacturing steps. For example, the through-hole 312 can be applied to the liquid injection step, the chemical conversion step, or other steps.

[0281] Specifically, the through-hole 312 is for injecting electrolyte into the internal space of the case 20. When injection is required, the injection head of the injection device is pressed against the bottom wall 311a of the terminal recess 311, and the injection head injects the electrolyte into the case 20 through the through-hole 312. During the chemical formation process of the battery cell 7, gas is generated inside the case body 21, and the through-hole 312 can also be used to communicate with an external negative pressure device to draw in and discharge the gas inside the case 20.

[0282] In some embodiments, the battery cell 7 further includes a sealing plate 70, at least a portion of which is housed in a terminal recess 311, connected to a terminal body 31, and covers and seals the through hole 312.

[0283] After completing processes such as the electrolyte injection process, the sealing plate 70 is attached to the electrode terminal 30 to seal the through hole 312 and reduce the risk of electrolyte leakage.

[0284] In some embodiments, the sealing plate 70 is welded to the terminal body 31.

[0285] In some embodiments, the battery cell 7 further includes a sealing pin 80, which is inserted into the through hole 312.

[0286] In some embodiments, the terminal recess 311 has a stepped surface, and at least a portion of the sealing plate 70 is housed in the terminal recess 311 and supported by the stepped surface.

[0287] In some embodiments, the battery cell 7 is a cylindrical battery cell. In other embodiments, the battery cell 7 is a rectangular battery cell.

[0288] Figure 10 is a schematic local cross-sectional view of a battery cell according to some embodiments of this application.

[0289] As shown in FIG. 10, in some embodiments, the second stopper portion 33 has an inclined surface 331 facing the second surface 233. Along the radial direction of the electrode lead-out hole 231, the distance between the inclined surface 331 and the second surface 233 in the thickness direction Z gradually increases. At least a part of the third insulating portion 43 is located between the inclined surface 331 and the second surface 233, and is attached to the inclined surface 331 and the second surface 233.

[0290] For example, the inclined surface 331 can be formed by chamfering the second stopper portion 33 or providing a fillet thereon.

[0291] The arrangement of the inclined surface 331 enlarges the space between the second stopper portion 33 and the second surface 233. When the insulating member 40 is pressed by the second stopper portion 33 during the assembly process, the material can flow between the second surface 233 and the inclined surface 331, thereby reducing overflow of the material.

[0292] FIG. 11 is a schematic partial cross-sectional view of a battery cell according to some embodiments of the present application, FIG. 12 is a schematic diagram illustrating one step in an assembly process of a battery cell according to some embodiments of the present application, and FIG. 13 is another schematic diagram illustrating another step in the assembly process of a battery cell according to some embodiments of the present application.

[0293] As shown in FIG. 11, in some embodiments, the electrode terminal 30 is provided with a slit 34, the slit 34 is recessed from an outer circumferential surface 31a of the terminal body 31, and is adjacent to a connection position between the terminal body 31 and the second stopper portion 33.

[0294] The slit 34 can disperse stress during the folding forming process of the second stopper portion 33, and reduce stress concentration.

[0295] As shown in Figures 12 and 13, in some embodiments, the electrode terminal 30 has a first recess 35 on the side away from the electrode assembly 10, and a second stopper portion 33 is formed by folding the side wall 351 of the first recess outward. A second recess 36 is provided on the outside of the side wall 351 of the first recess, and the second recess 36 is intended to guide the bending of the side wall 351 of the first recess and is configured to be filled after the second stopper portion 33 is formed, thereby forming a slit 34.

[0296] By creating the first recess 35, a thin side wall 211 is formed at the electrode terminal 30. The electrode terminal 30 is attached to the wall portion 23 by folding back the side wall 351 of the first recess. The second recess 36 can guide the folding back of the side wall 351 of the first recess and can also provide space for material flow, thereby reducing material accumulation at the folding position, improving the shape of the electrode terminal 30, and lowering the difficulty of molding the electrode terminal 30.

[0297] In some embodiments, the cross-section of the second recess 36 is semicircular, triangular, trapezoidal, rectangular, or other shape.

[0298] As shown in Figure 13, after the second stopper portion 33 is folded and formed, the remaining portion of the first recess 35 forms the terminal recess 311.

[0299] Figure 14 is a schematic local cross-sectional view of a battery cell according to several embodiments of this application, and Figure 15 is an enlarged schematic view of the circular frame in Figure 14.

[0300] As shown in Figures 14 and 15, in some embodiments, the first insulating portion 41 includes a first insulating layer 411, a second insulating layer 412, and a third insulating layer 413 that are installed in a laminated manner, the first insulating layer 411 being bonded to the first surface 232, the second insulating layer 412 being located between the first insulating layer 411 and the third insulating layer 413, and at least a portion of the third insulating layer 413 being bonded to the connection portion 321.

[0301] The first insulating section 41 utilizes a multilayer composite structure, which can improve the overall performance of the first insulating section 41.

[0302] In some embodiments, the melting point of the second insulating layer 412 is higher than that of the first insulating layer 411, and the melting point of the second insulating layer 412 is higher than that of the third insulating layer 413.

[0303] The melting point of the first insulating layer 411 may be higher than, equal to, or lower than the melting point of the third insulating layer 413.

[0304] The second insulating layer 412 has a high melting point and is less likely to soften during the manufacturing and use of the battery cell 7, thereby insulating and isolating the wall portion 23 and the connection portion 321, reducing the risk of short circuits.

[0305] For example, even if the first insulating layer 411 and the third insulating layer 413 melt, the second insulating layer 412 can still provide an insulating isolation effect, thereby reducing the risk of short circuits.

[0306] In some embodiments, the difference between the melting point of the second insulating layer 412 and the melting point of the first insulating layer 411 is 20°C or more, thereby reducing the risk of the second insulating layer 412 softening or melting during the manufacturing and use of the battery cell 7.

[0307] In some embodiments, the difference between the melting point of the second insulating layer 412 and the melting point of the third insulating layer 413 is 20°C or more, thereby reducing the risk of the second insulating layer 412 softening or melting during the manufacturing and use of the battery cell 7.

[0308] In some embodiments, the melting point of the first insulating layer 411 is 140° or higher, and the melting point of the third insulating layer 413 is 140° or higher.

[0309] In some embodiments, the first insulating layer 41 comprises a polymer and a modified polymer, the modified polymer being formed by a modification treatment of the polymer. Both the first insulating layer 411 and the third insulating layer 413 contain a modified polymer, and the second insulating layer 412 contains a polymer.

[0310] By installing the modified polymer, the combined strength of the first insulating layer 411 and the wall portion 23, and the combined strength of the third insulating layer 413 and the connection portion 321 can be improved, thereby reducing the risk of connection failure between the first insulating layer 411 and the wall portion 23, and between the third insulating layer 413 and the connection portion 321.

[0311] In some embodiments, the second insulating layer 412 does not contain a modified polymer, thereby reducing the influence of modification on the polymer's performance and preserving the polymer's inherent properties, such as strength, melting point, or other properties. For example, the melting point of the polymer is higher than that of the modified polymer.

[0312] In some examples, the polymer comprises polypropylene or polyethylene terephthalate.

[0313] In some examples, a modified polymer can be formed by modifying the polymer and grafting polar functional groups onto it.

[0314] For example, a modified polymer can be formed by grafting maleic anhydride onto a polymer.

[0315] In some examples, the grafting rate of maleic anhydride in the first insulating layer 411 is greater than 0.1%, and the grafting rate of maleic anhydride in the third insulating layer 413 is greater than 0.1%.

[0316] In some embodiments, the first insulating layer 411 may be a modified high-strength composite adhesive, and the third insulating layer 413 may be a modified high-strength composite adhesive.

[0317] In some embodiments, a polymer plate material may be provided first, and then grafting may be performed on both sides of the plate material to form a first insulating layer 411, a second insulating layer 412, and a third insulating layer 413.

[0318] In several other alternative embodiments, the first insulating layer 41 is a single layer structure which is modified as a whole. In other words, the second insulating layer 412 also contains a modified polymer, and the first insulating layer 411, the second insulating layer 412, and the third insulating layer 413 have the same structure.

[0319] In some embodiments, the second insulating layer 42 and the third insulating layer 43 also have a three-layer structure.

[0320] Exemplary, in some embodiments, the third insulating portion 43 includes a fourth insulating layer 431, a fifth insulating layer 432, and a sixth insulating layer 433 which are installed in a laminated manner, the fourth insulating layer 431 being bonded to the second surface 233, the fifth insulating layer 432 being located between the fourth insulating layer 431 and the sixth insulating layer 433, and at least a portion of the sixth insulating layer 433 being bonded to the second stopper portion 33.

[0321] In some embodiments, the fourth insulating layer 431 comprises a polymer and a modified polymer, the sixth insulating layer 433 comprises a polymer and a modified polymer, and the fifth insulating layer 432 comprises a polymer but does not contain a modified polymer.

[0322] Figure 16 is a schematic cross-sectional view of a battery cell according to some other embodiments of the present application, and Figure 17 is an enlarged schematic view of the circular frame in Figure 16.

[0323] As shown in Figures 16 and 17, in some embodiments, the connecting portion 321 is located on the outside of the wall portion 23. The first surface 232 is the outer surface of the wall portion 23, and the second surface 233 is the inner surface of the wall portion 23.

[0324] In some embodiments, the electrode terminal 30 includes a first stopper portion 32, a second stopper portion 33, and a terminal body 31, wherein at least a portion of the terminal body 31 is housed in the electrode lead-out hole 231, and both the first stopper portion 32 and the second stopper portion 33 protrude from the outer peripheral surface 31a of the terminal body 31.

[0325] The first stopper portion 32 is located on the side of the wall portion 23 away from the electrode assembly 10 and includes a connecting portion 321, while the second stopper portion 33 is located on the side of the wall portion 23 facing the electrode assembly 10. In the thickness direction Z, a portion of the wall portion 23 is located between the second stopper portion 33 and the connecting portion 321.

[0326] In some embodiments, the insulating member 40 includes a first insulating portion 41, a second insulating portion 42, and a third insulating portion 43. The first insulating portion 41 is mounted on the first surface 232, and at least a portion of the first insulating portion 41 is located between the first surface 232 and the connection portion 321, covering the region of the first surface 232 that overlaps with the connection portion 321 in the thickness direction Z. The second insulating portion 42 is connected to the first insulating portion 41, surrounds the terminal body 31, and insulates and isolates the outer circumferential surface 31a of the terminal body 31 from the hole wall of the electrode lead-out hole 231. The third insulating portion 43 is mounted on the second surface 233 and insulates and isolates the second stopper portion 33 from the second surface 233.

[0327] In some embodiments, during assembly, the electrode terminal 30 is inserted into the electrode exit hole 231 from the outside, and the electrode terminal 30 is pressed from the inside of the wall portion 23 to form the second stopper portion 33, and the electrode terminal 30 is riveted to the wall portion 23.

[0328] Figure 18 is a schematic diagram of the structure of a battery cell according to some other embodiments of this application.

[0329] As shown in Figure 18, in some embodiments, the case 20 includes a case body 21 and an end cover 22. The end cover 22 includes a wall portion 23. Correspondingly, the electrode terminals 30 and insulating member 40 are installed on the end cover 22.

[0330] The end cover 22, electrode terminals 30, and insulating member 40 are pre-assembled as an end cover assembly and can be assembled with other components such as the case body 21 and electrode assembly 10 to form a battery cell 7.

[0331] Figure 19 is a schematic cross-sectional view of a battery cell according to some other embodiments of this application.

[0332] As shown in Figure 19, in some embodiments, the electrode terminal 30 is fixed to the wall portion 23 by an insulating member 40.

[0333] In some embodiments, the electrode terminal 30 may be flat and be directly fixed to the wall portion 23 by the insulating member 40, eliminating the need for a riveted structure, thereby simplifying the structure of the electrode terminal 30 and the process of attaching the electrode terminal 30.

[0334] In some embodiments, the electrode terminal 30 may be located inside the wall portion 23 or outside the wall portion 23.

[0335] According to some embodiments of this application, the application further provides a battery comprising a plurality of battery cells of any one of the above embodiments.

[0336] According to some embodiments of this application, the application further provides a power consumption device that includes a battery cell of any of the embodiments described above, used for supplying electrical energy. The power consumption device may be any of the aforementioned devices or systems to which the battery cell is applied.

[0337] Referring to Figures 4 to 9, an embodiment of the present application provides a cylindrical battery cell 7 which includes an electrode assembly 10, a case 20, electrode terminals 30, and an insulating member 40.

[0338] The case 20 includes a case body 21 and an end cover 22. The case body 21 has an opening, and the end cover 22 is fitted over the opening. The case body 21 includes a wall portion 23 facing the end cover 22, and the wall portion 23 is provided with electrode extraction holes 231.

[0339] The electrode assembly 10 is housed in the case 20. The electrode assembly 10 includes a main body 12 and a tab 11, the tab 11 being located on the side of the main body 12 facing the wall 23.

[0340] The electrode terminal 30 includes a terminal body 31, a first stopper portion 32, and a second stopper portion 33. The terminal body 31 penetrates the electrode lead-out hole 231. The first stopper portion 32 protrudes from the outer circumferential surface 31a of the terminal body 31 and is located on the side of the wall portion 23 facing the electrode assembly 10, while the second stopper portion 33 protrudes from the outer circumferential surface 31a of the terminal body 31 and is located on the side of the wall portion 23 away from the electrode assembly 10. In the thickness direction Z, at least a portion of the wall portion 23 is located between the connecting portion 321 and the second stopper portion 33.

[0341] The first stopper portion 32 includes a connecting portion 321, and the projection of the connecting portion 321 along the thickness direction Z is located within the projection of the wall portion 23 along the thickness direction Z.

[0342] The wall portion 23 includes a first surface 232 and a second surface 233 installed on opposite sides along the thickness direction Z, the first surface 232 facing the connection portion 321 and the second surface 233 facing away from the connection portion 321.

[0343] The insulating member 40 connects the electrode terminals 30 to the case 20 and provides insulation and isolation between the electrode terminals 30 and the wall portion 23. The insulating member 40 is bonded to the wall portion 23 and the electrode terminals 30 by a thermocompression bonding process.

[0344] The insulating member 40 includes a first insulating portion 41, a second insulating portion 42, and a third insulating portion 43. The first insulating portion 41 is mounted on the first surface 232, the third insulating portion 43 is mounted on the second surface 233, and the second insulating portion 42 connects the first insulating portion 41 and the third insulating portion 43.

[0345] At least a portion of the first insulating portion 41 is located between the first surface 232 and the connection portion 321, and covers the region of the first surface 232 that overlaps with the connection portion 321 in the thickness direction Z. The second insulating portion 42 is connected to the first insulating portion 41, surrounds the terminal body 31, and insulates and isolates the outer circumferential surface 31a of the terminal body 31 from the hole wall of the electrode lead-out hole 231. The third insulating portion 43 insulates and isolates the second stopper portion 33 from the second surface 233.

[0346] While this application has been described with reference to preferred embodiments, various modifications are possible as long as they do not deviate from the scope of this application, and components can be replaced with equivalents, and in particular, any technical feature mentioned in each embodiment can be combined in any way, provided that there is no structural inconsistency. This application is not limited to the specific embodiments disclosed herein, but includes all technical ideas contained in the claims.

Claims

1. It is a battery cell, The case and, The electrode terminals installed in the aforementioned case, An electrode assembly housed within the case, wherein the electrode assembly includes an electrode assembly that includes a tab electrically connected to the electrode terminal, A battery cell comprising an insulating member for connecting the electrode terminals to the case and insulating and isolating the electrode terminals from the case.

2. The battery cell according to claim 1, wherein at least a portion of the insulating member is located between the electrode terminal and the case and is mounted on the electrode terminal and the case.

3. The battery cell according to claim 1 or 2, wherein the insulating member is bonded to the case and the electrode terminals.

4. The battery cell according to claim 3, wherein the insulating member is bonded to the case and the electrode terminals by a thermocompression bonding composite process.

5. The surface of the electrode terminal is provided with a passivation film connected to the insulating member, and / or The battery cell according to claim 3 or 4, wherein a passivation film connected to the insulating member is provided on the surface of the case.

6. The case includes a wall portion, the wall portion is provided with an electrode exit hole, the electrode terminal is installed in the wall portion and covers at least a portion of the electrode exit hole in the thickness direction of the wall portion, The battery cell according to any one of claims 1 to 5, wherein the insulating member connects the electrode terminal and the wall portion, and insulates and isolates the electrode terminal and the wall portion.

7. The battery cell according to claim 6, wherein the insulating member is for sealing the electrode lead-out hole.

8. The electrode terminal includes a connecting portion, the connecting portion is located on the side of the wall portion along the thickness direction, and the projection of the connecting portion along the thickness direction is located within the projection of the wall portion along the thickness direction. The battery cell according to claim 6 or 7, wherein at least a portion of the insulating member is located between the wall portion and the connection portion and is attached to the wall portion and the connection portion.

9. The projected area along the thickness direction of the portion of the insulating member located between the wall portion and the connecting portion is 50 mm ２ The above is true, and selectively, the area of ​​the projection along the thickness direction of the portion of the insulating member located between the wall portion and the connecting portion is 100 mm². ２ The battery cell according to claim 8.

10. The battery cell according to claim 8 or 9, wherein the thickness of the portion of the insulating member located between the wall portion and the connection portion is 20 μm to 2000 μm, and selectively, the thickness of the portion of the insulating member located between the wall portion and the connection portion is 50 μm to 1000 μm.

11. The wall portion includes a first surface and a second surface installed on opposite sides along the thickness direction of the wall portion, the first surface facing the connection portion, and the second surface facing away from the connection portion. The battery cell according to any one of claims 8 to 10, wherein the insulating member includes a first insulating portion attached to the first surface, and at least a portion of the first insulating portion is located between the first surface and the connection portion and covers a region of the first surface that overlaps with the connection portion in the thickness direction.

12. The battery cell according to claim 11, wherein in the radial direction of the electrode lead-out hole, the first insulating portion protrudes from the connection portion.

13. The battery cell according to claim 11 or 12, wherein both the first insulating portion and the connecting portion are installed surrounding the electrode lead-out hole.

14. The battery cell according to any one of claims 11 to 13, wherein the connection portion is located on the side of the wall portion facing the electrode assembly.

15. Both the wall portion and the connecting portion are annular in shape. The battery cell according to claim 14, wherein the ratio of the outer diameter of the connecting portion to the outer diameter of the wall portion is 0.3 to 0.8, and selectively, the ratio of the outer diameter of the connecting portion to the outer diameter of the wall portion is 0.5 to 0.

7.

16. The first surface includes a first region and a second region, the first region being covered by the first insulating portion, and the second region surrounding the first region. The battery cell according to claim 14 or 15, further comprising an insulating isolation member, wherein in the thickness direction, at least a portion of the insulating isolation member is located between the second region and the tab.

17. The battery cell according to claim 16, wherein the insulating isolation member completely isolates the second region from the tab in the thickness direction.

18. The battery cell according to claim 16 or 17, wherein the insulating isolation member overlaps with the first insulating portion in the thickness direction.

19. The insulating isolation member includes an insulating plate and an insulating cylinder, the insulating cylinder surrounding the tab, and the insulating plate connected to the end of the insulating cylinder facing the first surface and positioned between the first surface and the tab. The battery cell according to any one of claims 16 to 18, wherein the insulating plate surrounds the outside of the connection portion.

20. The present invention further includes a current collector, the current collector being located on the side of the tab facing the first surface and connected to the tab, and the electrode terminal being located on the side of the current collector being away from the tab and connected to the current collector, The battery cell according to claim 19, wherein at least a portion of the insulating plate is located between the current collector and the first surface and is mounted on the current collector.

21. The electrode terminals include a terminal body and a first stopper portion that are connected to each other, at least a portion of the terminal body is housed in the electrode lead-out hole, and the first stopper portion protrudes from the outer circumferential surface of the terminal body. The battery cell according to any one of claims 14 to 20, wherein the first stopper portion includes the connecting portion.

22. The battery cell according to claim 21, wherein the insulating member further includes a second insulating portion, the second insulating portion is connected to the first insulating portion, surrounds the terminal body, and insulates and isolates the outer circumferential surface of the terminal body from the hole wall of the electrode extraction hole.

23. The battery cell according to claim 22, wherein the second insulating portion is attached to the outer circumferential surface of the terminal body and the hole wall of the electrode lead-out hole.

24. The electrode terminal further includes a second stopper portion, the second stopper portion protruding from the outer circumferential surface of the terminal body and located on the side of the wall portion away from the electrode assembly, The battery cell according to claim 22 or 23, wherein in the thickness direction, at least a portion of the wall portion is located between the connecting portion and the second stopper portion.

25. The battery cell according to claim 24, wherein the insulating member further includes a third insulating portion connected to the second insulating portion, the third insulating portion being mounted on the second surface and insulatingly separating the second stopper portion from the second surface.

26. The second stopper portion has an inclined surface facing the second surface, Along the radial direction of the electrode extraction hole, the distance between the inclined surface and the second surface in the thickness direction gradually increases. The battery cell according to claim 25, wherein at least a portion of the third insulating portion is located between the inclined surface and the second surface and is mounted on the inclined surface and the second surface.

27. The battery cell according to any one of claims 24 to 26, wherein the electrode terminal is provided with a slit, the slit extends from the outer circumferential surface of the terminal body and is close to the connection position between the terminal body and the second stopper portion.

28. The electrode terminal has a first recess on the side away from the electrode assembly, and the second stopper portion is formed by folding the side wall of the first recess outward. A second recess is provided on the outside of the side wall of the first recess, the second recess is for guiding the bending of the side wall of the first recess, and is configured to be filled after the second stopper portion is formed, thereby forming the slit, as described in claim 27.

29. The battery cell according to any one of claims 11 to 28, wherein the melting point of the first insulating portion is 140°C or higher.

30. The battery cell according to any one of claims 11 to 29, wherein the yield strength of the first insulating portion is 20 MPa or more.

31. The battery cell according to any one of claims 11 to 30, wherein the first insulating portion includes a first insulating layer, a second insulating layer, and a third insulating layer that are installed in a stack, the first insulating layer being bonded to the first surface, the second insulating layer being located between the first insulating layer and the third insulating layer, and at least a portion of the third insulating layer being bonded to the connection portion.

32. The battery cell according to claim 31, wherein the melting point of the second insulating layer is higher than the melting point of the first insulating layer, and the melting point of the second insulating layer is higher than the melting point of the third insulating layer.

33. The difference between the melting point of the second insulating layer and the melting point of the first insulating layer is 20°C or more, and / or The battery cell according to claim 32, wherein the difference between the melting point of the second insulating layer and the melting point of the third insulating layer is 20°C or more.

34. The first insulating portion comprises a polymer and a modified polymer, the modified polymer being formed by performing a modification treatment on the polymer. The battery cell according to claims 31 to 33, wherein both the first insulating layer and the third insulating layer contain the modified polymer, and the second insulating layer contains the polymer.

35. The battery cell according to claim 34, wherein the second insulating layer does not contain the modified polymer.

36. The battery cell according to claim 34 or 35, wherein the polymer comprises polypropylene or polyethylene terephthalate.

37. The case includes a case body and an end cover, the case body having an opening, and the end cover being placed over the opening. The battery cell according to any one of claims 6 to 36, wherein the case body includes the wall portion installed opposite the end cover.

38. A battery comprising a plurality of battery cells as described in any one of claims 1 to 37.

39. A power consumption device comprising a battery according to claim 38, wherein the battery is for providing electrical energy.

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