Battery cell, battery apparatus, and electric device

Abstract

Provided are a battery cell (12), a battery apparatus (100), and an electric device, which belong to the technical field of batteries. The battery cell (12) comprises a casing (121), a first electrode terminal (125), an electrode assembly (122), a first current collecting member (1220), a first insulating member (123) and a second insulating member (127), wherein the casing (121) comprises a first wall (1210). The electrode assembly (122) is accommodated in the casing (121), and the electrode assembly (122) comprises a first tab (1224). The first electrode terminal (125) is arranged on the first wall (1210). The first current collecting member (1220) is arranged between the first wall (1210) and the electrode assembly (122), the first current collecting member (1220) comprises a first portion (1221) and a second portion (1222) which are connected to each other, the first portion (1221) is connected to the first electrode terminal (125), and the second portion (1222) is connected to the first tab (1224). The first insulating member (123) is arranged between the first wall (1210) and the electrode assembly (122) so as to insulate and isolate the first wall (1210) from the electrode assembly (122). The second insulating member (127) is arranged between the second portion (1222) and the first wall (1210), and the second insulating member (127) has a higher melting point than the first insulating member (123). The battery cell (12) has high reliability.

Description

Battery cells, battery packs and electrical devices Cross-references to related applications

[0001] This application claims priority to Chinese patent application 202422507385.2, filed on October 16, 2024, entitled “Battery cell, battery device and power consumption device”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery technology, specifically to a battery cell, a battery device, and an electrical device. Background Technology

[0003] Energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. For electric vehicles, battery technology is a crucial factor in their development.

[0004] Improving the reliability of individual battery cells is a pressing issue in battery technology. Summary of the Invention

[0005] In view of the above problems, this application provides a battery cell, a battery device, and an electrical device that can improve the reliability of the battery cell.

[0006] In a first aspect, this application provides a battery cell, which includes a casing, a first electrode terminal, an electrode assembly, a first current collector, a first insulating member, and a second insulating member. The casing includes a first wall. The electrode assembly is housed within the casing and includes a first tab. The first electrode terminal is disposed on the first wall. The first current collector is disposed between the first wall and the electrode assembly, and includes a first portion and a second portion connected to each other. The first portion is connected to the first electrode terminal, and the second portion is connected to the first tab. The first insulating member is disposed between the first wall and the electrode assembly to insulate and isolate the first wall and the electrode assembly. The second insulating member is disposed between the second portion and the first wall, and the melting point of the second insulating member is greater than that of the first insulating member.

[0007] In the technical solution of this application embodiment, since the second insulating member is disposed between the second part and the first wall, and the melting point of the second insulating member is greater than that of the first insulating member, the second insulating member is more difficult to melt than the first insulating member. Even if the first insulating member partially melts in the later stage of thermal runaway of the battery cell, the second insulating member can still play a certain role in insulating and isolating the second part and the first wall, thereby reducing the risk of battery cell fire and explosion caused by short circuit between the first current collector and the first wall, which is beneficial to improving the reliability of the battery cell.

[0008] In one or more embodiments of the first aspect, the melting point of the second insulating element is greater than 250°C.

[0009] In the above scheme, when the melting point of the second insulating component is greater than 250°C, the second insulating component has a high melting point and is not easily melted in the later stage of thermal runaway of the battery cell. Even if the first insulating component partially melts in the later stage of thermal runaway of the battery cell, the second insulating component can still play a certain role in insulating and isolating the second part and the first wall, thereby reducing the risk of short circuit between the second part and the first wall causing the battery cell to catch fire and explode.

[0010] In one or more embodiments of the first aspect, the material of the second insulating element includes perfluoroalkyl ethylene or polyimide.

[0011] The above-mentioned solution uses perfluoroalkyl ethylene or polyimide, which have both high melting points and high toughness. Even if the second insulating part melts, the risk of the falling second insulating part piercing the separator and causing a short circuit between the positive and negative electrode plates of the electrode assembly is relatively low, which can further reduce the risk of battery cell fire or explosion.

[0012] In one or more embodiments of the first aspect, the second insulating member is at least partially embedded in the first insulating member.

[0013] In the above scheme, since the second insulating element is at least partially embedded in the first insulating element, the second insulating element can share part of the space with the first insulating element.

[0014] In one or more embodiments of the first aspect, the first insulating member is provided with a through hole extending along the thickness direction of the first wall, and the second insulating member is disposed within the through hole.

[0015] In the above scheme, since the second insulating member is disposed within the through hole, on the one hand, the second insulating member can share part of the space with the first insulating member, which is beneficial to improving the energy density of the battery cell. On the other hand, the through hole can serve as a positioning reference for the second insulating member, facilitating its assembly.

[0016] In one or more embodiments of the first aspect, the first insulating member includes a substrate and a boss, the boss protruding from the substrate toward the electrode assembly and abutting against the electrode assembly. A through hole is provided in the substrate.

[0017] In the above scheme, the boss that abuts against the electrode assembly can reduce the risk of electrode assembly shaking, which is beneficial to improving the structural stability of the battery cell. At the same time, when assembling the second insulating component into the through hole, due to the setting of the boss, there is a certain space between the base and the surface of the boss facing away from the base, which makes the operation space for positioning and connecting the second insulating component to the through hole larger and the assembly more convenient.

[0018] In one or more embodiments of the first aspect, the thickness of the second insulating member is less than or equal to the thickness of the substrate along the thickness direction of the first wall.

[0019] In the above scheme, along the thickness direction of the first wall, the thickness of the second insulating member is less than or equal to the thickness of the substrate. While meeting the basic insulation performance requirements of the second insulating member, this reduces its volume and weight, thereby increasing the energy density of the battery cell. Simultaneously, during normal use of the battery cell, because the second insulating member is relatively thin, its presence does not increase the difficulty of heat dissipation compared to the first insulating member without one. This means the heat conduction distance within the second insulating member is relatively short, allowing the battery cell to maintain good heat dissipation performance and reducing the risk of heat accumulation accelerating the melting of the second insulating member and causing a short circuit between the second part and the first wall.

[0020] In one or more embodiments of the first aspect, the substrate has a first surface facing the electrode assembly and a second surface facing away from the electrode assembly. The second insulating member does not protrude from the first surface, and / or the second insulating member does not protrude from the second surface.

[0021] In the above solution, since the second insulating member does not protrude from the first surface, while sharing a portion of the space with the first insulating member, the placement of the second insulating member will not interfere with the assembly of the second part with the electrode terminal. Similarly, since the second insulating member does not protrude from the second surface, while sharing a portion of the space with the first insulating member, the placement of the second insulating member will not interfere with the assembly of the first insulating member with the first wall.

[0022] In one or more embodiments of the first aspect, the thickness of the second insulating member is H1 along the thickness direction of the first wall, satisfying 0.2mm≤H1≤2mm.

[0023] In the above scheme, when H1 ≥ 0.2 mm, the second insulating component has a larger thickness, making it more difficult to melt. This provides better insulation between the second part and the first wall during the later stages of thermal runaway in the battery cell, thus contributing to higher reliability of the battery cell. When H1 ≤ 2 mm, the second insulating component is smaller in size and occupies less space, which helps to achieve higher energy density in the battery cell. Therefore, when 0.2 mm ≤ H1 ≤ 2 mm, the battery cell can achieve both high reliability and high energy density.

[0024] In one or more embodiments of the first aspect, the orthographic projection of the second portion lies within the orthographic projection of the second insulating member in the same projection plane perpendicular to the thickness direction of the first wall.

[0025] In the above scheme, within the same projection plane perpendicular to the thickness direction of the first wall, the orthographic projection of the second part lies within the orthographic projection of the second insulating member. Even if the first insulating member partially melts in the later stages of thermal runaway of the battery cell, the second insulating member completely covers the second part, which can significantly reduce the risk of the battery cell catching fire and exploding due to a short circuit between the second part and the first wall, thus improving the reliability of the battery cell.

[0026] In one or more embodiments of the first aspect, the minimum distance between the edge of the orthographic projection of the second insulating member and the edge of the orthographic projection of the second part is D1, satisfying: 1mm≤D1≤10mm.

[0027] In the above scheme, when D1 ≥ 1mm, there is a large distance between the edge of the orthographic projection of the second insulating component and the edge of the orthographic projection of the second part, reducing the risk of the second part being exposed and short-circuiting with the first wall, and thus increasing the reliability of the battery cell. When D1 ≤ 10mm, the amount of the second insulating component used is smaller, which helps to reduce the cost of the battery cell while meeting insulation performance requirements. Therefore, when 1mm ≤ D1 ≤ 10mm, the battery cell can achieve both high reliability and low cost.

[0028] In one or more embodiments of the first aspect, the second insulating member is thermally fused to the first insulating member.

[0029] In the above scheme, the second insulating component is connected to the first insulating component by heat fusion, resulting in relatively high connection strength and suitability for automated production, which is beneficial to improving the assembly efficiency of battery cells.

[0030] In one or more embodiments of the first aspect, the second insulating member is connected to the first wall.

[0031] In the above scheme, the first wall can serve as the assembly base for the second insulating component, reducing the assembly difficulty of the second insulating component. Furthermore, in embodiments where the first wall has relatively high material strength, connecting the second insulating component to the first wall allows the first wall to distribute the assembly stress of the second insulating component to a certain extent, which is beneficial for improving the structural stability of the assembled second insulating component.

[0032] In one or more embodiments of the first aspect, the battery cell further includes a pressure relief mechanism disposed on the first wall.

[0033] In the above scheme, during the thermal runaway of a battery cell, some of the gas in the emissions is released through a pressure relief mechanism located on the first wall. In the later stages of thermal runaway, the internal pressure of the battery cell exceeds the external pressure, causing the electrode assembly to tend to move closer to the first wall. At this point, the risk of the electrode assembly coming into contact with the first wall is high. Providing a second insulating component can significantly reduce the risk of the battery cell catching fire and exploding due to a short circuit between the second component and the first wall.

[0034] In one or more embodiments of the first aspect, the second portion is connected to the first tab to form a first connection portion, and in the same projection plane perpendicular to the thickness direction of the first wall, the orthographic projection of the second insulating member at least partially overlaps with the first connection portion.

[0035] In the above scheme, the location where the second part forms the first connection with the first electrode tab generally has weaker structural strength. When the first current collector is subjected to force, the location of the first connection is more prone to relatively large deformation, and the risk of short-circuiting between the first connection and the first wall is high. By setting the orthographic projection of the second insulating member to at least partially overlap with the first connection in the same projection plane perpendicular to the thickness direction of the first wall, the risk of battery cell fire or explosion caused by short-circuiting between the first current collector and the first wall can be significantly reduced.

[0036] In one or more embodiments of the first aspect, multiple electrode assemblies are provided, and a second part is connected to the first tabs of the multiple electrode assemblies to form multiple first connection portions. Multiple second insulating members are provided, and the multiple second insulating members correspond one-to-one with the multiple first connection portions.

[0037] In the above scheme, since the positions of the first connecting parts are all provided with second insulating parts, the risk of short circuit between each first connecting part and the first wall can be reduced, thereby improving the reliability of the battery cell.

[0038] In one or more embodiments of the first aspect, the electrode assembly includes a second tab. The battery cell further includes a second electrode terminal, a second current collector, and a third insulating member. The second electrode terminal is disposed on the first wall. The second current collector is disposed between the first wall and the electrode assembly, and the second current collector includes a third portion and a fourth portion connected to each other, the third portion connecting to the second electrode terminal and the fourth portion connecting to the second tab. The third insulating member is disposed between the fourth portion and the first wall, and the melting point of the third insulating member is greater than the melting point of the first insulating member.

[0039] In the above scheme, because the third insulating component is located between the fourth part and the first wall, and the melting point of the third insulating component is higher than that of the first insulating component, the third insulating component is more difficult to melt than the first insulating component. Even if the first insulating component partially melts in the later stage of thermal runaway of the battery cell, the third insulating component can still play a certain role in insulating and isolating the fourth part and the first wall, thereby reducing the risk of battery cell fire and explosion caused by short circuit between the second current collector and the first wall, which is beneficial to improving the reliability of the battery cell.

[0040] Secondly, this application provides a battery device that includes the battery cell described in one or more of the above embodiments.

[0041] In the above solutions, since the battery cells in one or more of the above embodiments have high reliability, the battery device including the battery cells in one or more of the above embodiments also has high reliability.

[0042] Thirdly, this application provides an electrical device that includes the battery cell or battery device in one or more of the above embodiments. Since the battery cell or battery device in one or more of the above embodiments has high reliability, the electrical device that includes the battery cell or battery device in one or more of the above embodiments also has high reliability.

[0043] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0044] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0045] Figure 1 is a schematic diagram of the vehicle structure according to some embodiments of this application;

[0046] Figure 2 is an exploded view of a battery device according to some embodiments of this application;

[0047] Figure 3 is an exploded view of a battery cell according to some embodiments of this application;

[0048] Figure 4 is an exploded view of a partial structure of a battery cell according to some embodiments of this application;

[0049] Figure 5 is a schematic diagram of a portion of the structure of a battery cell according to some embodiments of this application;

[0050] Figure 6 is a cross-sectional view of a partial structure of a battery cell according to some embodiments of this application;

[0051] Figure 7 is a magnified view of part A in Figure 6.

[0052] 1000 - Vehicle; 200 - Controller; 300 - Motor; 100 - Battery Unit; 11 - Housing; 111 - First Housing; 112 - Second Housing; 12 - Battery Cell; 121 - Shell; 1210 - First Wall; 1211 - End Cap; 1212 - Housing; 122 - Electrode Assembly; 1220 - First Current Collector; 1221 - First Part; 1222 - Second Part; 1223 - Main Body; 1224 - First Tab; 1225 - Second Tab ; 123-First insulating component; 1231-Through hole; 1232-Base; 12321-First surface; 12322-Second surface; 1233-Boss; 1234-Protrusion; 1235-Through hole; 1236-Drain hole; 124-Second current collecting component; 1241-Third part; 1242-Fourth part; 125-First electrode terminal; 126-Pressure relief mechanism; 127-Second insulating component; 128-Third insulating component; 129-Second electrode terminal. Detailed Implementation

[0053] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0055] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0056] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0057] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0058] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0059] Battery cells include, but are not limited to, lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc.

[0060] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, reduces the risk of short circuits while allowing active ions to pass through.

[0061] In some embodiments, the separator is a separator membrane. The separator membrane can be any known porous structure separator membrane with good chemical and mechanical stability.

[0062] As an example, the material of the separator may include at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer may be the same or different. The separator may be a separate component located between the positive and negative electrodes, or it may be attached to the surfaces of the positive and negative electrodes.

[0063] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0064] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel-like, or solid.

[0065] In some implementations, the electrode assembly is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0066] In some implementations, the electrode assembly is a stacked structure.

[0067] As an example, multiple positive and negative electrode plates can be set, and multiple positive and multiple negative electrode plates can be stacked alternately.

[0068] As an example, multiple positive electrode sheets can be set, and negative electrode sheets are folded to form multiple stacked folded segments, with a positive electrode sheet sandwiched between adjacent folded segments.

[0069] As an example, both the positive and negative electrode sheets are folded to form multiple stacked folded segments.

[0070] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0071] As an example, the separator can be continuously arranged between any adjacent positive or negative electrode plates by folding or rolling.

[0072] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0073] In some embodiments, the electrode assembly is provided with tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0074] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing may be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0075] In some embodiments, the battery cell may further include a pressure relief mechanism disposed on the housing, which is used to release the internal pressure of the battery cell when the internal pressure or temperature of the battery cell reaches a predetermined value.

[0076] As an example, a battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic battery cells, such as hexagonal prismatic battery cells.

[0077] The battery apparatus mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells connected in series, parallel, or mixed connections via a busbar.

[0078] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form a single module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0079] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cells housed within the housing.

[0080] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0081] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0082] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0083] In some embodiments, the battery can be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0084] The following discussion will primarily focus on rectangular battery cells. It should be understood that the embodiments described below are also applicable in some respects to cylindrical battery cells, pouch cell cells, or blade cell cells.

[0085] In a typical battery cell structure, a battery cell includes a casing, electrode assemblies, and electrolyte. The casing includes end caps and a housing; the end caps close the openings of the housing to define a space for accommodating the electrode assemblies.

[0086] The development of battery technology must take into account multiple design factors, such as energy density, cycle life, discharge capacity, charge / discharge rate and other performance parameters. In addition, the reliability of the battery device also needs to be considered.

[0087] A typical battery cell includes a casing, electrode assemblies, and electrode terminals mounted on the casing. The electrical energy inside the battery cell is led out through a second part of the electrode assembly, which is electrically connected to the electrode terminals. To reduce the risk of internal short circuits within the battery cell, an insulating structure, such as plastic, is typically placed between the second part and the casing. However, when a battery cell experiences thermal runaway and is in the later stages of thermal runaway, the internal temperature is high, increasing the risk of the plastic insulation melting. Once the plastic melts, the risk of a short circuit between the second part and the casing increases significantly. In this situation, a short circuit could lead to a fire or explosion of the battery cell, resulting in low reliability.

[0088] In view of this, this application provides a battery cell including a casing, a first electrode terminal, an electrode assembly, a first current collector, a first insulating member, and a second insulating member. The casing includes a first wall. The electrode assembly is housed within the casing and includes a first tab. The first electrode terminal is disposed on the first wall. The first current collector is disposed between the first wall and the electrode assembly, and includes a first portion and a second portion connected to each other. The first portion is connected to the first electrode terminal, and the second portion is connected to the first tab. The first insulating member is disposed between the first wall and the electrode assembly to insulate and isolate the first wall and the electrode assembly. The second insulating member is disposed between the second portion and the first wall, and the melting point of the second insulating member is greater than that of the first insulating member. Because the second insulating member is disposed between the second portion and the first wall, and the melting point of the second insulating member is greater than that of the first insulating member, the second insulating member is more difficult to melt than the first insulating member. Even if the first insulating component partially melts in the later stage of thermal runaway of the battery cell, the second insulating component can still play a certain role in insulating and isolating the second part and the first wall, thereby reducing the risk of battery cell fire and explosion caused by short circuit between the first current collector and the first wall, which is conducive to improving the reliability of the battery cell.

[0089] The technical solutions described in the embodiments of this application are applicable to battery cells, battery devices, and electrical devices using battery devices.

[0090] Electrical devices include, but are not limited to: electric vehicles, electric cars, ships, and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft.

[0091] For ease of explanation, the following embodiments will be described using a vehicle as an example of an electrical device according to an embodiment of this application.

[0092] Please refer to Figure 1, which is a structural schematic diagram of a vehicle 1000 provided in some embodiments of this application. A battery device 100 is disposed inside the vehicle 1000, and the battery device 100 may be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000.

[0093] The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, for the power needs of the vehicle 1000 during startup, navigation and driving.

[0094] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0095] Please refer to Figure 2, which is an exploded view of a battery device 100 provided in some embodiments of this application. The battery device 100 may include a battery cell 12 and a housing 11, with the battery cell 12 housed within the housing 11.

[0096] The housing 11 is a component that houses the battery cell 12, providing a space for the battery cell 12. The housing 11 can adopt various structures. In some embodiments, the housing 11 may include a first housing 111 and a second housing 112, which overlap each other to define a space for accommodating the battery cell 12. The first housing 111 and the second housing 112 can have various shapes, such as cuboid or cylindrical. The first housing 111 can be a hollow structure with an opening on one side, and the second housing 112 can also be a hollow structure with an opening on one side. The opening side of the second housing 112 overlaps the opening side of the first housing 111, thus forming a housing 11 with a accommodating space. Alternatively, the first housing 111 can be a hollow structure with an opening on one side, and the second housing 112 can be a plate-like structure, overlapping the opening side of the first housing 111, thus forming a housing 11 with a accommodating space. The first housing 111 and the second housing 112 can be sealed by a sealing element, such as a sealing ring or sealant.

[0097] In the battery device 100, there can be one or more battery cells 12. If there are multiple battery cells 12, they can be connected in series, in parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 12 are connected in both series and parallel. Alternatively, multiple battery cells 12 can first be connected in series, in parallel, or in a mixed configuration to form a battery module, and then multiple battery modules can be connected in series, in parallel, or in a mixed configuration to form a whole, which is then housed within the housing 11. Another option is that all battery cells 12 can be directly connected in series, in parallel, or in a mixed configuration, and then the whole consisting of all battery cells 12 is housed within the housing 11.

[0098] Please refer to Figure 3, which is an exploded view of a battery cell 12 provided in some embodiments of this application. The battery cell 12 may include a housing 121 and an electrode assembly 122, the electrode assembly 122 being housed within the housing 121.

[0099] In some embodiments, the housing 121 may include a housing 1212 and an end cap 1211, the housing 1212 having an opening and the end cap 1211 closing the opening of the housing 1212.

[0100] The housing 1212 is a component used to house the electrode assembly 122. The housing 1212 can be a hollow structure with an opening at one end, or a hollow structure with openings at both opposite ends. The housing 1212 can have various shapes, such as cylindrical or cuboid. The housing 1212 can be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy. The electrode assembly 122 can be partially or completely located within the housing 1212.

[0101] End cap 1211 is a component that closes the opening of housing 1212 to isolate the internal environment of battery cell 12 from the external environment. End cap 1211 and housing 1212 together define a receiving space for accommodating electrode assembly 122, electrolyte, and other components. End cap 1211 can be connected to housing 1212 by welding or roll sealing to close the opening of housing 1212. The shape of end cap 1211 can be adapted to the shape of housing 1212. For example, if housing 1212 is a cuboid structure, end cap 1211 can be a rectangular plate structure adapted to housing 1212; or if housing 1212 is a cylindrical structure, end cap 1211 can be a circular plate structure adapted to housing 1212. The material of end cap 1211 can also be various, such as copper, iron, aluminum, steel, aluminum alloy, etc. The materials of end cap 1211 and housing 1212 can be the same or different.

[0102] In an embodiment where the housing 1212 has an opening at one end, one end cap 1211 may be provided accordingly. In an embodiment where the housing 1212 has openings at opposite ends, two end caps 1211 may be provided accordingly. The two end caps 1211 respectively close the two openings of the housing 1212, and the two end caps 1211 and the housing 1212 together define the receiving space.

[0103] In some embodiments, the battery cell 12 may further include electrode terminals disposed on the housing 121. The electrode terminals are used for electrical connection with the tabs of the electrode assembly 122 to input or output electrical energy of the battery cell 12. The electrode terminals may be disposed on the housing 1212 of the housing 121 or on the end cap 1211 of the housing 121. The electrode terminals and tabs may be directly connected, for example, by welding the electrode terminals to the tabs. The electrode terminals and tabs may also be indirectly connected, for example, by connecting the electrode terminals and tabs indirectly through a current collector. The current collector may be a metal conductor, such as copper, iron, aluminum, steel, aluminum alloy, etc. Exemplarily, the electrode terminals may be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, etc. Of course, in some embodiments, the electrode terminals may also be composite materials, that is, the electrode terminals are formed by connecting two different metal materials, for example, by hot pressing or cold pressing.

[0104] In some embodiments, the battery cell 12 may further include a pressure relief mechanism 126, which may be disposed on the end cap 1211 or the housing 1212. The pressure relief mechanism 126 may be a pressure relief component installed on the housing 1212 or the end cap 1211, such as an explosion-proof plate or a safety valve. The pressure relief mechanism 126 may also be integrally formed with the end cap 1211 or the housing 1212. The pressure relief mechanism 126 may have a pressure relief groove to allow the battery cell 12 to crack along the groove when pressure is released. The pressure relief groove may be a groove extending along a closed trajectory, such as a circular trajectory, a rectangular trajectory, etc.; the pressure relief groove may also be a groove extending along a non-closed trajectory, such as an H-shaped trajectory, a Y-shaped trajectory, a V-shaped trajectory, a U-shaped trajectory, etc.

[0105] According to some embodiments of this application, referring to Figures 3-5, this application provides a battery cell 12. The battery cell 12 includes a housing 121, a first electrode terminal 125, an electrode assembly 122, a first current collector 1220, a first insulating member 123, and a second insulating member 127. The housing 121 includes a first wall 1210. The electrode assembly 122 is housed within the housing 121 and includes a first tab 1224. The first electrode terminal 125 is disposed on the first wall 1210. The first current collector 1220 is disposed between the first wall 1210 and the electrode assembly 122. The first current collector 1220 includes a first portion 1221 and a second portion 1222 connected to each other. The first portion 1221 is connected to the first electrode terminal 125, and the second portion 1222 is connected to the first tab 1224. The first insulating member 123 is disposed between the first wall 1210 and the electrode assembly 122 to insulate and isolate the first wall 1210 and the electrode assembly 122. The second insulating element 127 is disposed between the second part 1222 and the first wall 1210, and the melting point of the second insulating element 127 is greater than the melting point of the first insulating element 123.

[0106] The first part 1221 is connected to the first electrode terminal 125, and the second part 1222 is connected to the first tab 1224. Since the structural stability of the first electrode terminal 125 is higher than that of the first tab 1224, the first part 1221 connected to the first electrode terminal 125 is more difficult to deform. In other words, when the first current collector 1220 is subjected to force, the second part 1222 is more likely to undergo a larger deformation, that is, the second part 1222 is more likely to come into contact with the first wall 1210 and thus short-circuit.

[0107] In some embodiments, the housing 121 can be a sealed structure or a non-sealed structure. As an example, when the housing 121 is a sealed structure, it can protect the electrode assembly 122 and prevent, to some extent, electrolyte leakage. When the housing 121 is a non-sealed structure, it can still protect the electrode assembly 122, and a sealing bag may be included between the housing 121 and the electrode assembly 122. The sealing bag is used to encapsulate the electrode assembly 122 and the electrolyte, etc. Specifically, the sealing bag can be a bag-shaped insulating component or an aluminum-plastic film.

[0108] The first wall 1210 can be located on any wall of the outer casing 121.

[0109] In some embodiments, the first insulating member 123 is provided with a through hole 1235, the through hole 1235 being positioned corresponding to the first electrode terminal 125, and at least a portion of the first electrode terminal 125 passing through the through hole 1235 and connecting to the second portion 1222.

[0110] In some embodiments, the first wall 1210 may be located in the housing 1212, on the wall with the largest outer surface area.

[0111] In some embodiments, the first wall 1210 is an end cap 1211. The end cap 1211 closes the opening of the housing 1212. For example, as shown in Figures 6 and 7, along the thickness direction of the end cap 1211, the end cap 1211 has an inner surface facing the electrode assembly 122, an outer surface facing away from the electrode assembly 122, and an outer peripheral surface connecting the inner and outer surfaces, the outer peripheral surface connecting with the inner peripheral surface of the housing 1212 to close the opening of the housing 1212. In other embodiments, the housing 1212 has an end face connecting its outer peripheral surface and inner peripheral surface, the inner surface of the end cap 1211 connecting with the end face to close the opening of the housing 1212.

[0112] Electrode assembly 122 is located within the receiving space defined by housing 1212 and end cap 1211. Electrode assembly 122 can be a stacked structure or a wound structure. There can be one or more electrode assemblies 122 in housing 1212. If there are multiple electrode assemblies 122, they can be stacked. For example, multiple electrode assemblies 122 can be stacked along the stacking direction of the flat region of one of the electrode assemblies 122. The flat region is the straight portion of electrode assembly 122. If electrode assembly 122 is a stacked structure, it is a stacked electrode assembly 122, and the entire electrode assembly 122 can be a flat region. If electrode assembly 122 is a wound structure, it also has a corner region, and the flat region has a corner region at least at one end along the direction intersecting the flat region.

[0113] The first current collector 1220 is used to draw electrical energy from the electrode assembly 122. The electrode assembly 122 includes a main body 1223 and a first tab 1224, with the first tab 1224 disposed at one end of the main body 1223. The main body 1223 is the main component of the electrode assembly 122 that undergoes electrochemical reactions in the battery cell 12. Exemplarily, the first tab 1224 is connected to the end of the main body 1223 facing the wall in the thickness direction of the first wall 1210, that is, in the thickness direction of the first wall 1210, the first tab 1224 is located between the main body 1223 and the first wall 1210, so that the first tab 1224 can be connected to the first electrode terminal 125 through the first current collector 1220. It should be noted that the first tab 1224 of the electrode assembly 122 can be a component formed by stacking and connecting regions of the positive electrode sheet that are not coated with a positive active material layer, or a component formed by stacking and connecting regions of the negative electrode sheet that are not coated with a negative active material layer. If the first tab 1224 is used as the positive electrode of the output electrode assembly 122, then the first tab 1224 is a component formed by stacking and connecting the regions of the positive electrode sheet that are not coated with a positive active material layer; if the first tab 1224 is used as the negative electrode of the output electrode assembly 122, then the first tab 1224 is a component formed by stacking and connecting the regions of the negative electrode sheet that are not coated with a negative active material layer. Of course, in some embodiments, the electrode assembly 122 may also include a second tab 1225, the polarity of which is opposite to that of the first tab 1224.

[0114] The first current collector 1220, also known as an adapter, connects to the first electrode tab 1224. The first current collector 1220 is connected to the first electrode terminal 125 to facilitate the current collector drawing out electrical energy from the electrode assembly 122. The first portion 1221 is the part of the first current collector 1220 that connects to the first electrode terminal 125. For example, the first current collector 1220 and the first electrode terminal 125 are connected by welding, and the first portion 1221 is the area on the first current collector 1220 where the solder joint forms a solder mark with the first electrode terminal 125.

[0115] The second insulating member 127 is disposed between the second portion 1222 and the first wall 1210, meaning that the second insulating member 127 can be connected to the second portion 1222, the first wall 1210, or both. Alternatively, the second insulating member 127 can be located between neither the second portion 1222 nor the first wall 1210.

[0116] The material of the first insulating component 123 may include, but is not limited to, polypropylene.

[0117] The material of the second insulating component 127 may include, but is not limited to, perfluoroalkyl ethylene, polyimide, etc.

[0118] The melting point of the material of the second insulating component 127 is greater than that of the material of the first insulating component 123. In other words, the second insulating component 127 is more resistant to high temperature and less prone to melting than the first insulating component 123. When the internal temperature of the battery cell 12 is too high, the first insulating component 123 will be softened or melted before the second insulating component 127.

[0119] It should be noted that the melting point of the material of the second insulating member 127 is the temperature at which the second insulating member 127 changes from a hard solid to a liquid state or is softened and melted into a molten viscous flow state. Similarly, the melting point of the material of the first insulating member 123 is the temperature at which the insulating member changes from a hard solid to a liquid state or is softened and melted into a molten viscous flow state.

[0120] In the technical solution of this application embodiment, since the second insulating member 127 is disposed between the second portion 1222 and the first wall 1210, and the melting point of the second insulating member 127 is greater than that of the first insulating member 123, the second insulating member 127 is more difficult to melt than the first insulating member 123. Even if the first insulating member 123 partially melts in the later stage of thermal runaway of the battery cell 12, the second insulating member 127 can still play a certain role in insulating and isolating the second portion 1222 and the first wall 1210, thereby reducing the risk of fire and explosion of the battery cell 12 caused by short circuit between the current collector and the first wall 1210, which is beneficial to improving the reliability of the battery cell 12.

[0121] According to some embodiments of this application, the melting point of the second insulating element 127 is greater than 250°C.

[0122] The melting point of the second insulating element 127 can be any value greater than 250°C, such as any one of 255°C, 260°C, 265°C, 270°C, 275°C, 280°C, 285°C, 290°C, 295°C, 300°C, 305°C, 310°C, 315°C, 320°C, 330°C, 340°C, 350°C, 360°C, 370°C, 380°C, 390°C, 400°C, or a range between any two.

[0123] In the above scheme, when the melting point of the second insulating component 127 is greater than 250°C, the second insulating component 127 has a high melting point and is not easily melted in the later stage of thermal runaway of the battery cell 12. Even if the first insulating component 123 partially melts in the later stage of thermal runaway of the battery cell 12, the second insulating component 127 can still play a certain role in insulating and isolating the second part 1222 and the first wall 1210, thereby reducing the risk of short circuit between the second part 1222 and the first wall 1210 causing the battery cell 12 to catch fire and explode.

[0124] According to some embodiments of this application, the material of the second insulating element 127 includes perfluoroalkyl vinyl or polyimide.

[0125] The above-mentioned solution uses perfluoroalkyl ethylene or polyimide, which has both a high melting point and high toughness. Even if the second insulating part 127 melts, the risk of the falling second insulating part 127 piercing the separator and causing a short circuit between the positive and negative electrode plates of the electrode assembly 122 is relatively low, which can further reduce the risk of fire or explosion of the battery cell 12.

[0126] According to some embodiments of this application, referring to Figures 3-5, the second insulating member 127 is at least partially embedded in the first insulating member 123.

[0127] The second insulating member 127 is at least partially embedded in the first insulating member 123, meaning that the second insulating member 127 and the first insulating member 123 share a portion of space.

[0128] In some embodiments, the second insulating member 127 has a groove on its surface along the thickness direction of the first wall 1210, and at least a portion of the second insulating member 127 is disposed in the groove. The second insulating member 127 may have grooves on two opposite surfaces along the thickness direction of the first wall 1210, the two grooves being positioned correspondingly, and the number of second insulating members 127 may be at least two, with each groove containing a second insulating member 127.

[0129] In the above scheme, since the second insulating member 127 is at least partially embedded in the first insulating member 123, the second insulating member 127 can share part of the space with the first insulating member 123.

[0130] According to some embodiments of this application, please refer to Figures 3-5. The first insulating member 123 is provided with a through hole 1231 extending along the thickness direction of the first wall 1210, and the second insulating member 127 is disposed in the through hole 1231.

[0131] The through hole 1231 can be formed by machining or other means after the first insulating part 123 is formed. Of course, the through hole 1231 can also be integrally formed with the first insulating part 123 by injection molding or other means.

[0132] The second insulating member 127 is disposed within the through hole 1231, meaning that at least a portion of the second insulating member 127 is located within the through hole 1231. The fact that one portion of the second insulating member 127 is located outside the through hole 1231 and another portion is located within the through hole 1231 can also be understood as the second insulating member 127 being disposed within the through hole 1231.

[0133] The shape of the through hole 1231 can be circular, semi-circular, polygonal, annular, etc.

[0134] In the above scheme, since the second insulating member 127 is disposed in the through hole 1231, on the one hand, the second insulating member 127 can share part of the space with the first insulating member 123, which is beneficial to improving the energy density of the battery cell 12. On the other hand, the through hole 1231 can serve as a positioning reference for the second insulating member 127, which facilitates the assembly of the second insulating member 127.

[0135] According to some embodiments of this application, referring to Figures 3-5, the first insulating member 123 includes a base 1232 and a boss 1233. The boss 1233 protrudes from the base 1232 toward the electrode assembly 122 and abuts against the electrode assembly 122. A through hole 1231 is provided in the base 1232.

[0136] In some embodiments, multiple bosses 1233 are provided, with two bosses 1233 located at both ends of the first insulating member 123 along a first direction, wherein the first direction, the thickness direction of the first wall 1210, and the stacking direction of the flat region of the electrode assembly 122 are perpendicular to each other. The bosses 1233 pressing against the electrode assembly 122 can reduce the risk of the electrode assembly 122 wobbling. In other embodiments, along the first direction, one boss 1233 is located between the two aforementioned bosses 1233.

[0137] In some embodiments, the boss 1233 may also be a ring structure.

[0138] In some embodiments, the second insulating member 127 is thermally fused to the first insulating member 123, and the second insulating member 127 is thermally fused to the wall of the through hole 1231.

[0139] In some embodiments, the second insulating member 127 is connected to the first wall 1210, and after the battery cell 12 is assembled, a portion of the second insulating member 127 extends into the through hole 1231.

[0140] In the above scheme, the boss 1233 that abuts against the electrode assembly 122 can reduce the risk of the electrode assembly 122 shaking, which is beneficial to improving the structural stability of the battery cell 12. At the same time, when the second insulating member 127 is assembled into the through hole 1231, due to the setting of the boss 1233, there is a certain space between the base 1232 and the surface of the boss 1233 facing away from the base 1232, which makes the operation space for positioning and connecting the second insulating member 127 and the through hole 1231 larger and the assembly more convenient.

[0141] According to some embodiments of this application, referring to Figures 3-5, along the thickness direction of the first wall 1210, the thickness of the second insulating member 127 is less than or equal to the thickness of the substrate 1232.

[0142] The thickness of the second insulating element 127 can refer to the maximum value of multiple measurements obtained after measuring the second insulating element 127 multiple times.

[0143] The thickness of substrate 1232 can refer to the maximum value of multiple measurements obtained after measuring substrate 1232 multiple times.

[0144] In the above scheme, along the thickness direction of the first wall 1210, the thickness of the second insulating member 127 is less than or equal to the thickness of the substrate 1232. While satisfying the basic insulation performance of the second insulating member 127, this helps to reduce the volume and weight of the second insulating member 127, thereby increasing the energy density of the battery cell 12. Simultaneously, during normal use of the battery cell 12, because the thickness of the second insulating member 127 is relatively thin, compared to the first insulating member 123 without the second insulating member 127, the addition of the second insulating member 127 does not increase the difficulty of heat dissipation. That is, the heat conduction distance within the second insulating member 127 is relatively short, allowing the battery cell 12 to maintain good heat dissipation performance and reducing the risk of heat accumulation accelerating the melting of the second insulating member 127, leading to a short circuit between the second part 1222 and the first wall 1210.

[0145] According to some embodiments of this application, referring to Figures 3-5, the substrate 1232 has a first surface 12321 facing the electrode assembly 122 and a second surface 12322 facing away from the electrode assembly 122. The second insulating member 127 does not protrude from the first surface 12321, and / or, the second insulating member 127 does not protrude from the second surface 12322.

[0146] In some embodiments, the second insulating member 127 is flush with both the first surface 12321 and the second surface 12322. This arrangement helps to reduce the risk of stress concentration at the joint between the second insulating member 127 and the first insulating member 123, and helps to ensure that the second insulating member 127 and the first insulating member 123 have high connection stability, thereby reducing the risk of insulation failure caused by the second insulating member 127 falling off.

[0147] In the above solution, since the second insulating member 127 does not protrude from the first surface 12321, while the second insulating member 127 shares a portion of the space with the first insulating member 123, the arrangement of the second insulating member 127 will not interfere with the assembly of the second portion 1222 and the electrode terminal. Since the second insulating member 127 does not protrude from the second surface 12322, while the second insulating member 127 shares a portion of the space with the first insulating member 123, the arrangement of the second insulating member 127 will not interfere with the assembly of the first insulating member 123 and the first wall 1210.

[0148] According to some embodiments of this application, please refer to Figures 3-5. Along the thickness direction of the first wall 1210, the thickness of the second insulating member 127 is H1, which satisfies 0.2mm≤H1≤2mm.

[0149] Along the thickness direction of the first wall 1210, the thickness of the second insulating member 127 can be any value between 0.2 mm and 2 mm, for example, any one of the following values ​​or a range between any two: 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm.

[0150] In the above scheme, when H1 ≥ 0.2 mm, the second insulating member 127 has a larger thickness, making it more difficult to melt. In the later stages of thermal runaway in the battery cell 12, it provides better insulation between the second part 1222 and the first wall 1210, which is beneficial for the battery cell 12 to have higher reliability. When H1 ≤ 2 mm, the second insulating member 127 has a smaller volume and occupies less space, which is beneficial for the battery cell 12 to have higher energy density. Therefore, when 0.2 mm ≤ H1 ≤ 2 mm, the battery cell 12 can achieve both high reliability and high energy density.

[0151] According to some embodiments of this application, please refer to Figures 3-7. In the same projection plane perpendicular to the thickness direction of the first wall 1210, the orthographic projection of the second portion 1222 is located within the orthographic projection of the second insulating member 127.

[0152] In the same projection plane perpendicular to the thickness direction of the first wall 1210, the orthographic projection of the second portion 1222 lies within the orthographic projection of the second insulating member 127. This means that when the electrode assembly 122 moves close to the first wall 1210 along its thickness direction, the second insulating member 127 will completely cover the second portion 1222. Even when the second insulating member 127 is not completely melted, the second portion 1222 will always be partially blocked by the second insulating member 127.

[0153] In the above scheme, within the same projection plane perpendicular to the thickness direction of the first wall 1210, the orthographic projection of the second part 1222 lies within the orthographic projection of the second insulating member 127. Even if the first insulating member 123 partially melts in the later stage of thermal runaway of the battery cell 12, since the second insulating member 127 completely covers the second part 1222, the risk of short-circuiting between the second part 1222 and the first wall 1210, causing the battery cell 12 to catch fire and explode, can be significantly reduced, which is beneficial to improving the reliability of the battery cell 12.

[0154] According to some embodiments of this application, referring to Figures 3-5, the minimum distance between the edge of the orthographic projection of the second insulating member 127 and the edge of the orthographic projection of the second part 1222 is D1, which satisfies: 1mm≤D1≤10mm.

[0155] The minimum distance between the edge of the orthographic projection of the second insulating member 127 and the edge of the orthographic projection of the second part 1222 can be any value between 1 mm and 10 mm, for example, any point value or a range between any two of the following: 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm.

[0156] In the above scheme, when D1 ≥ 1mm, there is a large distance between the edge of the orthographic projection of the second insulating member 127 and the edge of the orthographic projection of the second part 1222, reducing the risk of the second part 1222 being exposed and short-circuiting with the first wall 1210, and thus increasing the reliability of the battery cell 12. When D1 ≤ 10mm, the amount of the second insulating member 127 used is smaller, which helps to reduce the cost of the battery cell 12 while meeting insulation performance requirements. Therefore, when 1mm ≤ D1 ≤ 10mm, the battery cell 12 can achieve both high reliability and low cost.

[0157] According to some embodiments of this application, please refer to Figures 3-5, the second insulating member 127 and the first insulating member 123 are thermally fused together.

[0158] In some embodiments, the substrate 1232 has a first surface 12321 facing the electrode assembly 122 and a second surface 12322 facing away from the electrode assembly 122. The second surface 12322 is thermally fused to the first wall 1210 to connect the substrate 1232 and the first wall 1210. The thermally fused connection of the substrate 1232 and the first wall 1210 forms a welded portion. For example, to ensure a stable connection strength between the substrate 1232 and the first wall 1210 after thermal fusion, multiple protrusions 1234 are typically provided on the second surface 12322 to reduce the risk of unstable connection between the substrate 1232 and the first wall 1210 due to material deformation after thermal fusion. In this case, since the second insulating member 127 is disposed within the through hole 1231, this arrangement only requires the first surface 12321 to complete the fit between the second insulating member 127 and the first insulating member 123, as described above with a clearance fit. There is no need to machine clearance holes on the second insulating member 127 to avoid the protrusions 1234. The assembly is relatively simple and efficient, eliminating the need to consider the tolerance between the clearance hole and the protrusion 1234, which could prevent the second insulating member 127 from fitting properly. In other embodiments, multiple protrusions 1234 are provided, spaced circumferentially along the through hole 1231; that is, multiple welded portions are provided, distributed circumferentially along the through hole 1231. This arrangement, while reducing assembly difficulty, also ensures a high connection strength between the first wall 1210 and the first insulating member 123.

[0159] In the above scheme, the second insulating component 127 and the first insulating component 123 are connected together by heat fusion, which has relatively high connection strength and is suitable for automated production, thus improving the assembly efficiency of the battery cell 12.

[0160] According to some embodiments of this application, please refer to Figures 3-5, the second insulating member 127 is connected to the first wall 1210.

[0161] In some embodiments, the second insulating member 127 is thermally fused to the first wall 1210.

[0162] In some embodiments, the second insulating member 127 is bonded to the first wall 1210.

[0163] In some embodiments, the first wall 1210 is an end cap 1211, and the second insulating member 127 is disposed in the through hole 1231. The second insulating member 127 can be pre-connected to the end cap 1211. While the end cap 1211 closes the opening of the housing 1212, the second insulating member 127 extends into the through hole 1231 to realize the cooperation between the second insulating member 127 and the first insulating member 123.

[0164] In the above scheme, the first wall 1210 can serve as the assembly base 1232 for the second insulating component 127, reducing the assembly difficulty of the second insulating component 127. Simultaneously, in embodiments where the material strength of the first wall 1210 is relatively high, connecting the second insulating component 127 to the first wall 1210 allows the first wall 1210 to disperse the assembly stress of the second insulating component 127 to a certain extent, which is beneficial for improving the structural stability of the second insulating component 127 after assembly.

[0165] According to some embodiments of this application, please refer to Figures 3-4. The battery cell 12 also includes a pressure relief mechanism 126, which is disposed on the first wall 1210.

[0166] In some embodiments, the first insulating member 123 is provided with a drain hole 1236 extending through its thickness direction. The drain hole 1236 corresponds to the position of the pressure relief mechanism 126. When the battery cell 12 experiences thermal runaway, some of the emissions can pass through the drain hole 1236 and be discharged from the battery cell 12 via the pressure relief mechanism 126, thereby improving the pressure relief efficiency and reducing the risk that the first insulating member 123 will rapidly melt and fail due to excessively high internal temperature of the battery cell 12 caused by untimely pressure relief.

[0167] In the above scheme, when the battery cell 12 experiences thermal runaway, some of the gas in the emissions is discharged by the pressure relief mechanism 126 located on the first wall 1210. In the later stages of thermal runaway, the internal pressure of the battery cell 12 is greater than its external pressure, and the electrode assembly 122 tends to move closer to the first wall 1210. At this time, the risk of the electrode assembly 122 coming into contact with the first wall 1210 is high. Providing a second insulating element 127 can significantly reduce the risk of the battery cell 12 catching fire and exploding due to a short circuit between the second part 1222 and the first wall 1210.

[0168] According to some embodiments of this application, please refer to Figures 3-5. The second part 1222 is connected to the first tab 1224 to form a first connecting part. In the same projection plane perpendicular to the thickness direction of the first wall 1210, the orthographic projection of the second insulating member 127 at least partially overlaps with the first connecting part.

[0169] The second part 1222 and the first tab 1224 can form a first connection portion by riveting or welding. In some embodiments, the second part 1222 and the first tab 1224 are welded to form the first connection portion, which is the weld mark formed by the two. The location where the weld mark is formed generally has lower strength than other locations on the second part 1222, and is more prone to deformation, such as arching, when the first current collector 1220 is subjected to force. Therefore, by setting the orthographic projection of the second insulating member 127 to at least partially overlap with the first connection portion in the same projection plane perpendicular to the thickness direction of the first wall 1210, the risk of short circuit between the first current collector 1220 and the first wall 1210 leading to fire or explosion of the battery cell 12 can be significantly reduced.

[0170] In the above scheme, the location where the second part 1222 and the first tab 1224 form the first connection part generally has weaker structural strength. When the first current collector 1220 is subjected to force, the location of the first connection part is more prone to relatively large deformation, and the risk of short-circuiting between the first connection part and the first wall 1210 is high. By setting the orthographic projection of the second insulating member 127 to at least partially overlap with the first connection part in the same projection plane perpendicular to the thickness direction of the first wall 1210, the risk of the battery cell 12 catching fire or exploding due to short-circuiting between the first current collector 1220 and the first wall 1210 can be significantly reduced.

[0171] According to some embodiments of this application, please refer to Figures 3-5. Multiple electrode assemblies 122 are provided. A second part 1222 is connected to the first tab 1224 of the multiple electrode assemblies 122 to form multiple first connecting parts. Multiple second insulating members 127 are provided, and the multiple second insulating members 127 correspond one-to-one with the multiple first connecting parts.

[0172] In some embodiments, a plurality of electrode components 122 are arranged along the stacking direction of the flat region of the electrode components 122.

[0173] In the above scheme, since the positions of the first connecting parts are all provided with the second insulating member 127, the risk of short circuit between each position of the first connecting part and the first wall 1210 can be reduced, thereby improving the reliability of the battery cell 12.

[0174] According to some embodiments of this application, referring to Figures 3-5, the electrode assembly 122 includes a second tab 1225. The battery cell 12 also includes a second electrode terminal 129, a second current collector 124, and a third insulating member 128. The second electrode terminal 129 is disposed on the first wall 1210. The second current collector 124 is disposed between the first wall 1210 and the electrode assembly 122, and includes a third portion 1241 and a fourth portion 1242 connected to each other. The third portion 1241 is connected to the second electrode terminal 129, and the fourth portion 1242 is connected to the second tab 1225. The third insulating member 128 is disposed between the fourth portion 1242 and the first wall 1210, and the melting point of the third insulating member 128 is greater than the melting point of the first insulating member 123.

[0175] The first tab 1224 and the second tab 1225 have opposite polarities. In some embodiments, if the first current collector 1220 is used as the positive electrode of the output electrode assembly 122, then the second current collector 124 is used as the negative electrode of the output electrode assembly 122.

[0176] In some embodiments, the first current collector 1220 and the second current collector 124 have the same structure.

[0177] In some embodiments, the third insulating member 128 has the same structure as the second insulating member 127.

[0178] The third insulating element 128 is disposed between the fourth part 1242 and the first wall 1210, meaning that the third insulating element 128 can be connected to the fourth part 1242, the first wall 1210, or both. Alternatively, the third insulating element 128 can be located between neither the fourth part 1242 nor the first wall 1210.

[0179] The material of the third insulating component 128 may include, but is not limited to, perfluoroalkyl ethylene, polyimide, etc.

[0180] The melting point of the material of the third insulating component 128 is greater than that of the material of the first insulating component 123. In other words, the third insulating component 128 is more resistant to high temperature and less prone to melting than the first insulating component 123. When the internal temperature of the battery cell 12 is too high, the first insulating component 123 will be softened or melted before the third insulating component 128.

[0181] It should be noted that the melting point of the material of the third insulating element 128 is the temperature at which the third insulating element 128 changes from a hard solid to a liquid state or is softened and melted into a molten viscous flow state.

[0182] In the above scheme, since the third insulating element 128 is disposed between the fourth part 1242 and the first wall 1210, and the melting point of the third insulating element 128 is greater than that of the first insulating element 123, the third insulating element 128 is more difficult to melt than the first insulating element 123. Even if the first insulating element 123 partially melts in the later stage of thermal runaway of the battery cell 12, the third insulating element 128 can still play a certain role in insulating and isolating the fourth part 1242 and the first wall 1210, thereby reducing the risk of fire and explosion of the battery cell 12 caused by short circuit between the second current collector 124 and the first wall 1210, which is beneficial to improving the reliability of the battery cell 12.

[0183] According to some embodiments of this application, referring to FIG2, this application provides a battery device 100, which includes the battery cell 12 in one or more of the above embodiments.

[0184] In the above scheme, since the battery cell 12 in one or more of the above embodiments has high reliability, the battery device 100 including the battery cell 12 in one or more of the above embodiments also has high reliability.

[0185] According to some embodiments of this application, please refer to FIG1. ​​This application provides an electrical device that includes the battery cell 12 or battery device 100 in one or more of the above embodiments. Since the battery cell 12 or battery device 100 in one or more of the above embodiments has high reliability, the electrical device including the battery cell 12 or battery device 100 in one or more of the above embodiments also has high reliability.

[0186] According to some embodiments of this application, referring to Figures 3-7, this application provides a battery cell 12. The battery cell 12 includes a housing 121, a first electrode terminal 125, a second electrode terminal, two electrode assemblies 122, a pressure relief mechanism 126, a first current collector 1220, a second current collector 124, a first insulating member 123, a second insulating member 127, and a third insulating member 128. The housing 121 includes an end cap 1211 and a shell 1212. The shell 1212 has an opening, and the end cap 1211 closes the opening. The first electrode terminal 125 and the second electrode terminal 129 are both disposed on the end cap 1211. The pressure relief mechanism 126 is disposed on the end cap 1211.

[0187] Two electrode assemblies 122 are arranged along the stacking direction of the flat region of the electrode assembly 122;

[0188] The electrode assembly 122 is disposed inside the housing 121. The electrode assembly 122 includes a first electrode tab 1224 and a second electrode tab 1225, and the first electrode tab 1224 and the second electrode tab 1225 have opposite polarities.

[0189] The first current collector 1220 includes a first portion 1221 and two second portions 1222. The two second portions 1222 are correspondingly disposed with the first tabs 1224 of the two electrode assemblies 122. The first portion 1221 is connected to the first electrode terminal 125, and the second portions 1222 are connected to the first tabs 1224. A first insulating member 123 is disposed between the end cap 1211 and the electrode assembly 122 to insulate and isolate the end cap 1211 and the electrode assembly 122. A second insulating member 127 is disposed between the second portions 1222 and the end cap 1211. The melting point of the second insulating member 127 is greater than that of the first insulating member 123. The second insulating member 127 is made of polyimide. The first insulating member 123 is made of polypropylene. The second insulating member 127 and the first insulating member 123 are thermally fused together. The second current collector 124 includes a third part 1241 and two fourth parts 1242. The third part 1241 is connected to the second electrode terminal 129, and the two fourth parts 1242 are correspondingly disposed with the second tabs 1225 of the two electrode assemblies 122, and are connected to the second tabs 1225. A third insulating member 128 is disposed between the fourth part 1242 and the end cap 1211. The melting point of the third insulating member 128 is greater than that of the first insulating member 123. The material of the third insulating member 128 is polyimide. The third insulating member 128 is thermally fused to the first insulating member 123.

[0190] The first insulating member 123 has a plurality of through holes 1231 extending along the thickness direction of the end cap 1211. A second insulating member 127 and a third insulating member 128 are disposed within a portion of the through holes 1231. The first insulating member 123 includes a base 1232 and a boss 1233. The boss 1233 protrudes from the base 1232 toward the electrode assembly 122 and abuts against the electrode assembly 122. The through holes 1231 are disposed in the base 1232. The base 1232 has a first surface 12321 facing the electrode assembly 122 and a second surface 12322 facing away from the electrode assembly 122. The second insulating member 127 and the third insulating member 128 are both flush with the first surface 12321 and the second surface 12322. In the same projection plane perpendicular to the thickness direction of the end cap 1211, the orthographic projection of the second part 1222 is located within the orthographic projection of the second insulating member 127, and the orthographic projection of the fourth part 1242 is located within the orthographic projection of the third insulating member 128.

[0191] Even if the first insulating component 123 melts in the later stages of thermal runaway of the battery cell 12, the second insulating component 127 and the third insulating component 128 are more difficult to melt than the first insulating component 123. The second insulating component 127 and the third insulating component 128 can still effectively insulate and isolate the second part 1222 and the end cap 1211, as well as the fourth part 1242 and the end cap 1211, thus reducing the risk of the battery cell 12 catching fire or exploding due to short circuits between the second part 1222 and the end cap 1211, or between the fourth part 1242 and the end cap 1211.

[0192] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized by, include: The outer shell, including the first wall; An electrode assembly, housed within the housing, the electrode assembly including a first tab; The first electrode terminal is disposed on the first wall; A first current collector is disposed between the first wall and the electrode assembly. The first current collector includes a first part and a second part that are connected to each other. The first part is connected to the first electrode terminal, and the second part is connected to the first electrode tab. as well as A first insulating element is disposed between the first wall and the electrode assembly to insulate and isolate the first wall and the electrode assembly; The battery cell further includes a second insulating component, which is disposed between the second portion and the first wall, and the melting point of the second insulating component is greater than that of the first insulating component.

2. The battery cell of claim 1, wherein, The melting point of the second insulating component is greater than 250°C.

3. The battery cell according to claim 1 or 2, characterized in that, The material of the second insulating component includes perfluoroalkyl ethylene or polyimide.

4. The battery cell of any one of claims 1-3, wherein, The second insulating element is at least partially embedded in the first insulating element.

5. The battery cell of claim 4, wherein, The first insulating member is provided with a through hole extending along the thickness direction of the first wall, and the second insulating member is disposed in the through hole.

6. The battery cell of claim 5, wherein, The first insulating member includes a base and a boss, the boss protruding from the base toward the electrode assembly and abutting against the electrode assembly; The through hole is provided in the substrate.

7. The battery cell of claim 6, wherein, Along the thickness direction of the first wall, the thickness of the second insulating element is less than or equal to the thickness of the substrate.

8. The battery cell according to claim 6 or 7, characterized in that The substrate has a first surface facing the electrode assembly and a second surface facing away from the electrode assembly; The second insulating element does not protrude from the first surface, and / or the second insulating element does not protrude from the second surface.

9. The battery cell of any one of claims 1-8, wherein, Along the thickness direction of the first wall, the thickness of the second insulating element is H1, which satisfies 0.2mm≤H1≤2mm.

10. The battery cell of any one of claims 1-9, wherein, In the same projection plane perpendicular to the thickness direction of the first wall, the orthographic projection of the second portion lies within the orthographic projection of the second insulating element.

11. The battery cell of claim 10, wherein, The minimum distance between the edge of the orthographic projection of the second insulating member and the edge of the orthographic projection of the second part is D1, which satisfies: 1mm≤D1≤10mm.

12. The battery cell of any one of claims 1-11, wherein, The second insulating component is thermally fused to the first insulating component.

13. The battery cell of any one of claims 1-11, wherein, The second insulating element is connected to the first wall.

14. The battery cell of any one of claims 1-13, wherein, The battery cell also includes a pressure relief mechanism, which is disposed on the first wall.

15. The battery cell of any one of claims 1-14, wherein, The second part is connected to the first tab to form a first connection portion. In the same projection plane perpendicular to the thickness direction of the first wall, the orthographic projection of the second insulating member at least partially overlaps with the first connection portion.

16. The battery cell of claim 15, wherein, The electrode assembly is provided in multiple ways. The second part is connected to the first tab of the multiple electrode assemblies to form multiple first connection parts. The second insulating member is provided in multiple ways, and the multiple second insulating members correspond one-to-one with the multiple first connection parts.

17. The battery cell of any one of claims 1-16, wherein, The electrode assembly includes a second electrode tab; The battery cell also includes: The second electrode terminal is disposed on the first wall; A second current collector is disposed between the first wall and the electrode assembly. The second current collector includes a third portion and a fourth portion connected to each other. The third portion is connected to the second electrode terminal, and the fourth portion is connected to the second electrode tab. A third insulating element is disposed between the fourth portion and the first wall, and the melting point of the third insulating element is greater than that of the first insulating element.

18. A battery device, characterized by Includes the battery cell according to any one of claims 1-17.

19. An electrical device, comprising: The battery cell includes any one of claims 1-17 or the battery device according to claim 18, wherein the battery cell or the battery device is used to provide electrical energy to the electrical device.

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