Battery cells, battery packs, electrical devices and energy storage devices

Abstract

This application provides a battery cell, a battery device, a power consumption device, and an energy storage device, belonging to the field of battery technology. The battery cell includes a housing, an electrode assembly, and an end cap assembly. The housing has an opening at one end along a first direction, and the electrode assembly is housed within the housing. The end cap assembly includes an end cap and an insulating member. The end cap closes to the opening, and the insulating member is located on the side of the end cap facing the electrode assembly. The insulating member has a first surface facing the electrode assembly. First protrusions are respectively provided at both ends of the first surface along a second direction. A first groove is provided on a second surface of the first protrusions away from the first surface. The first groove extends along the second direction and is located at the intersection of the first protrusions and a first central plane of the electrode assembly. The first central plane is a plane passing through the center of the electrode assembly and perpendicular to a third direction. The first direction, the second direction, and the third direction are mutually perpendicular. The solution provided in this application can improve the problem of the electrode plates of the electrode assembly being easily damaged by pressure.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell, battery device, power supply device, and energy storage device. Background Technology

[0002] Energy conservation and emission reduction are key to sustainable social development, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of the automotive industry's sustainable development. For electric vehicles, battery technology is a crucial factor in their development.

[0003] In related technologies, for wound batteries, a winding process is required during processing. However, the spiral misalignment during the winding process is difficult to control, which can easily lead to the problem of the electrode sheets being damaged after assembly. Utility Model Content

[0004] This application aims to at least solve one of the technical problems existing in the background art. To this end, one object of this application is to provide a battery cell, battery device, power consumption device, and energy storage device to improve the problem of electrode damage in electrode assemblies.

[0005] An embodiment of the first aspect of this application provides a battery cell, comprising: a housing having an opening at one end along a first direction; an electrode assembly housed within the housing; and an end cap assembly including an end cap and an insulating member, the end cap closing onto the opening, the insulating member being disposed on the side of the end cap facing the electrode assembly, the insulating member having a first surface facing the electrode assembly, the first surface having first protrusions at both ends along a second direction, the first protrusions having first grooves on a second surface away from the first surface, the first grooves extending along the second direction, and the first grooves being located at the position where the first protrusions intersect with a first central plane of the electrode assembly; wherein the first central plane is a plane passing through the center of the electrode assembly and perpendicular to a third direction, and the first direction, the second direction, and the third direction are mutually perpendicular.

[0006] In the technical solution of this application embodiment, by setting a first groove at the intersection of the first center surface and the first protrusion of the electrode assembly, a groove design (first groove) can be made on the insulating part opposite to the electrode plate at the position where the electrode plate is prone to spiral misalignment and protrusion. This can reduce the mutual squeezing force between the electrode plate and the insulating part, improve the situation where the electrode plate is easily damaged by pressure, reduce the situation where the negative electrode coating material is wrinkled and deformed and produces burrs, thereby improving the self-discharge problem of the battery cell caused by the separator being punctured, and at the same time, it can also improve the thermal runaway problem caused by internal short circuit, thus improving the safety of the battery cell.

[0007] In some embodiments, the first groove extends through the first boss along a second direction.

[0008] In this embodiment, the first groove is a through groove, which can further reduce the mutual squeezing force between the electrode and the insulating component, and improve the situation where the electrode is easily damaged by pressure.

[0009] In some embodiments, the groove wall of the first groove and the second surface form a rounded transition.

[0010] This embodiment avoids the formation of sharp corners that easily cause stress concentration between the groove wall and the second surface of the first groove by setting a rounded transition. This can improve the problem of secondary damage to the electrode sheet caused by local stress concentration at the contact surface between the electrode assembly and the first boss, and further improve the situation where the electrode sheet of the electrode assembly is crushed.

[0011] In some embodiments, the depth H1 of the first groove along the first direction satisfies: 0.5mm≤H1≤1mm.

[0012] By setting the depth of the first groove to be no less than 0.5mm, the design can effectively avoid the position of severe spiral misalignment, and reduce the problem of the electrode being crushed. At the same time, setting the depth of the first groove to be no more than 1mm can prevent the formation of an excessively deep groove on the first boss, thereby reducing the impact of the slotting on the strength of the first boss and thus ensuring that the insulating component has sufficient support strength.

[0013] In some embodiments, a battery cell includes one or a plurality of electrode assemblies arranged along a third direction, and a first groove is provided at each position where the first boss intersects with the first center plane of each electrode assembly of the battery cell.

[0014] In this embodiment, by providing a first groove at the intersection of each electrode assembly and the first protrusion, the design can avoid the easily crushed positions of each electrode assembly, so that the parts of each electrode assembly with severe spiral misalignment have a lower risk of extrusion deformation, reducing the risk of the electrode sheet being crushed, thereby further improving the self-discharge problem of the battery cell caused by the separator being punctured, and also further improving the thermal runaway problem caused by internal short circuit, thus improving the safety of the battery cell.

[0015] In some embodiments, the second surface is further provided with a second groove extending in a third direction. The second groove is located inside the first boss facing another first boss, and the second groove also penetrates the inside of the first boss in the direction facing the other first boss.

[0016] By providing a second groove on the inner side of the first protrusion, which corresponds to the inner side of the bending area of ​​the electrode assembly, the situation where the electrode sheet inside the bending area is easily damaged by pressure can be improved, thereby improving the self-discharge problem caused by the separator being punctured in the battery cell. At the same time, it can also improve the thermal runaway problem caused by internal short circuit, thus improving the safety of the battery cell.

[0017] In some embodiments, the first boss has a first support portion located at both ends of the second groove along a third direction.

[0018] In this embodiment, the first support portion at both ends of the second groove can support the electrode assembly, thereby improving the phenomenon that the electrode sheet is easily damaged by pressure as much as possible without excessively reducing the support of the first protrusion on the electrode assembly.

[0019] In some embodiments, the second groove has a first sidewall perpendicular to the second direction, and the battery cell includes one or a plurality of electrode assemblies arranged along a third direction, wherein the first center plane of each electrode assembly of the battery cell is projected onto the plane of the first sidewall and the projection of each center plane onto the first sidewall is located within the first sidewall.

[0020] By extending the second groove along a third direction to cover the first center surface of each electrode assembly, the second groove can effectively avoid the inner side of the bending area of ​​the electrode assembly, thereby further improving the situation where the electrode sheet inside the bending area is easily damaged by pressure, improving the self-discharge problem caused by the separator being punctured in the battery cell, and also improving the thermal runaway problem caused by internal short circuit, thus improving the safety of the battery cell.

[0021] In some embodiments, a second boss is connected to the inner side of the first boss facing another first boss. The second boss is disposed on the first surface, and the height D1 of the first boss protruding from the first surface and the height D2 of the second boss protruding from the first surface satisfy: D1>D2; the depth H2 of the second groove along the first direction satisfies: H2=D1-D2.

[0022] In this embodiment, by setting a second boss that is connected to the first boss, the strength of the first boss can be enhanced. At the same time, by setting the depth of the second groove to the difference between the height of the first boss and the height of the second boss, the structural complexity can be reduced, making processing more convenient and reducing costs.

[0023] In some embodiments, the groove wall of the second groove and the second surface have a rounded transition.

[0024] This embodiment avoids the formation of sharp corners that easily cause stress concentration between the second groove wall and the second surface by setting a rounded transition. This can improve the problem of secondary damage to the electrode sheet caused by local stress concentration at the contact surface between the electrode assembly and the first boss, and further improve the situation where the electrode sheet of the electrode assembly is crushed.

[0025] In some embodiments, the dimension H3 of the second groove along the second direction satisfies: 2mm≤H3≤4mm.

[0026] By setting the range of the second groove size H3, the second groove size H3 can be kept below 4mm, so as not to significantly reduce the contact area between the electrode assembly and the insulating component, allowing the insulating component to effectively support the electrode assembly. At the same time, the second groove size H3 is not less than 2mm, which can also avoid areas that are prone to crushing as much as possible.

[0027] In some embodiments, the second surface is further provided with a third groove extending in a third direction. The third groove is located on the outer side of the first boss away from the other first boss, and the third groove also penetrates the outer side of the first boss in the direction away from the other first boss.

[0028] By providing a third groove on the outside of the first protrusion, which corresponds to the outer position of the bending area of ​​the electrode assembly, the situation where the electrode sheet on the outside of the bending area is easily damaged by pressure can be improved, thereby improving the self-discharge problem of the battery cell caused by the separator being punctured. At the same time, it can also improve the thermal runaway problem caused by internal short circuit, thus improving the safety of the battery cell.

[0029] In some embodiments, the first boss has a second support portion located at both ends of the third groove along a third direction.

[0030] In this embodiment, the second support portions at both ends of the third groove can support the electrode assembly, thereby minimizing the damage to the electrode sheet without excessively reducing the support of the first protrusion on the electrode assembly.

[0031] In some embodiments, the third groove has a second sidewall perpendicular to the second direction, and the battery cell includes one or a plurality of electrode assemblies arranged along the third direction, wherein the first center plane of each electrode assembly of the battery cell is projected onto the plane of the second sidewall and the projection of each center plane onto the second sidewall is located within the second sidewall.

[0032] By extending the third groove along the third direction to cover the first center surface of each electrode assembly, the third groove can effectively avoid the outer side of the bending area of ​​the electrode assembly, thereby further improving the situation where the electrode sheet on the outer side of the bending area is easily damaged by pressure, improving the self-discharge problem of the battery cell caused by the separator being punctured, and also improving the thermal runaway problem caused by internal short circuit, thus improving the safety of the battery cell.

[0033] In some embodiments, the groove wall of the third groove has a rounded transition with the second surface.

[0034] This embodiment avoids the formation of sharp corners that easily cause stress concentration between the groove wall and the second surface of the third groove by setting a rounded transition. This can improve the problem of secondary damage to the electrode sheet caused by local stress concentration at the contact surface between the electrode assembly and the first boss, and further improve the situation where the electrode sheet of the electrode assembly is crushed.

[0035] In some embodiments, the end cap assembly further includes: a pressure relief member disposed on the end cap; the second surface is further provided with a third protrusion, the third protrusion being located between two first protrusions, the orthographic projection of the third protrusion on the first surface at least partially coinciding with the orthographic projection of the pressure relief member on the first surface, and the height D3 of the third protrusion protruding from the first surface and the height D1 of the first protrusion protruding from the first surface satisfy: D1≥D3.

[0036] By setting a third protrusion, the electrode assembly can be further supported, making the electrode assembly more effective.

[0037] In some embodiments, the height D3 of the third boss protruding from the first surface is equal to the height D1 of the first boss protruding from the first surface; a fourth groove is provided on the fourth surface of the third boss away from the first surface, the fourth groove penetrates the third boss along the second direction, the fourth groove has a first bottom wall perpendicular to the first direction, and the orthographic projection of the first center plane of the electrode assembly on the plane where the first bottom wall is located is located within the first bottom wall.

[0038] By extending the fourth groove along the third direction to cover the first center surface of each electrode assembly, the fourth groove can effectively avoid the position of the first center surface of the electrode assembly, thereby further improving the situation where the electrode sheet in this area is easily damaged by pressure, thus improving the self-discharge problem of the battery cell caused by the separator being punctured, and also improving the thermal runaway problem caused by internal short circuit, thereby improving the safety of the battery cell.

[0039] An embodiment of the second aspect of this application provides a battery device that includes the battery cell described in the above embodiments.

[0040] An embodiment of the third aspect of this application provides an electrical device that includes the battery device described in the above embodiments, the battery device being used to provide electrical energy.

[0041] An embodiment of the fourth aspect of this application provides an energy storage device, which includes the battery device in the above embodiments, and the energy storage device is used to store electrical energy.

[0042] 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 above and other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0043] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0044] Figure 1 This is a schematic diagram of the vehicle structure according to some embodiments of this application;

[0045] Figure 2 This is an exploded view of the battery device according to some embodiments of this application;

[0046] Figure 3 This is an exploded structural diagram of a battery cell according to some embodiments of this application;

[0047] Figure 4 This is a schematic diagram of the structure of the end cap assembly according to some embodiments of this application;

[0048] Figure 5 for Figure 4 An explosion diagram;

[0049] Figure 6 for Figure 4 Schematic diagram of the middle end cap and insulating components;

[0050] Figure 7 for Figure 4 A bottom view;

[0051] Figure 8 for Figure 7 Sectional view at point BB;

[0052] Figure 9 for Figure 6 Schematic diagram of the structure of the insulating component;

[0053] Figure 10 for Figure 9 Top view;

[0054] Figure 11 for Figure 10 The left view;

[0055] Figure 12 for Figure 11 Enlarged view of point C in the middle;

[0056] Figure 13 This is a schematic diagram of the structure of an insulating element provided in some embodiments of this application.

[0057] Explanation of reference numerals in the attached figures:

[0058] 1000 vehicles;

[0059] Battery unit 100, controller 200, motor 300;

[0060] Battery cell assembly 10, battery cell 11, end cap 12, housing 13, electrode assembly 14, insulating component 15, opening 16, end cap assembly 30, pressure relief component 31, positive electrode post 32, negative electrode post 33, positive electrode riveting block 34, negative electrode riveting block 35, positive electrode insulating component 36, negative electrode insulating component 37, explosion-proof sheet 38;

[0061] First surface 111, second surface 112, first boss 120, first groove 130, second groove 140, first sidewall 141, bottom wall plane 142, first support part 143, second support part 144, second boss 150, third surface 151, third groove 160, second sidewall 161, third boss 170, fourth surface 171, fourth groove 180, first bottom wall 181;

[0062] Box 20, Part 1 21, Part 2 22. Detailed Implementation

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, "a and / or b" can represent three cases: a exists alone, a and b exist simultaneously, and b exists alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0068] 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).

[0069] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0070] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0071] Currently, the application of rechargeable batteries is becoming increasingly widespread, judging from market trends. They are not only used in energy storage systems for hydropower, thermal power, wind power, and solar power plants, but also extensively in various electronic devices, such as electric bicycles, electric motorcycles, and electric vehicles, as well as in military equipment and aerospace. As the application areas of rechargeable batteries continue to expand, the market demand is also constantly increasing.

[0072] In related technologies, winding is a critical process in the manufacturing of wound battery cells. Taking lithium batteries as an example, the electrode sheets in the electrode assembly of a wound battery cell are formed by winding. The design requires the negative electrode coating material to cover the positive electrode sheet. However, in actual production, the spiral misalignment during the winding process is difficult to control, easily leading to electrode protrusion. In practical applications, after the electrode assembly is encapsulated, the protruding electrode sheet can easily exert force on the insulating components and other supporting parts in the battery cell, causing the electrode sheet to be easily damaged. After the electrode sheet is damaged, the negative electrode coating material is prone to wrinkling and deformation, producing burrs. Since the hardness of the negative electrode coating material is slightly higher than that of the separator, it can easily puncture the separator, causing the positive and negative electrodes to overlap, thus triggering battery self-discharge. This results in low voltage and inability to function normally. In more severe cases, it can cause a short circuit inside the battery, creating a safety hazard.

[0073] It is understandable, especially for battery cells that are under constant vibration or inverted (under the influence of gravity), the interaction between the electrode assembly and the plastic parts is more severe, and the electrode sheets are more likely to be damaged. As a result, the self-discharge and safety hazards of the battery are also more serious.

[0074] To address at least one of the aforementioned problems, this application provides a battery cell that, by designing a way to avoid the corresponding insulating component at locations where the electrode is prone to misalignment or protrusion, reduces the mutual pressure between the electrode and the insulating component, improves the problem of the electrode being easily damaged by pressure, reduces the occurrence of burrs caused by wrinkling and deformation of the negative electrode coating material, thereby improving the self-discharge problem of the battery cell caused by the separator being punctured, and enhances the safety of the battery cell.

[0075] The technical solutions described in the embodiments of this application are applicable to battery cells, battery devices containing battery cells, electrical devices using battery devices, and energy storage devices.

[0076] The energy storage device utilizing battery devices as a power source in this application embodiment includes one or more battery clusters to enhance the voltage and capacity of the energy storage device. A battery cluster may include multiple battery devices, which are connected in series via a busbar to increase the voltage of the energy storage device. When the energy storage device includes multiple battery clusters, the multiple battery clusters are connected in parallel to increase the capacity of the energy storage device.

[0077] Energy storage devices can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems. Energy storage devices can store electrical energy as needed and output it when appropriate. For example, an energy storage device can store electrical energy during off-peak hours and provide power to relevant users or electrical devices during peak hours. The energy storage system provided in this application embodiment can be any power system that requires energy storage devices. As an example, the energy storage device is an energy storage container or an energy storage cabinet.

[0078] In this application embodiment, the power-consuming device using a battery as a power source can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0079] It should be understood that the technical solutions described in the embodiments of this application are not limited to the energy storage devices and electrical devices described above, but can also be applied to all battery devices including housings and electrical devices using battery devices. This can help improve the self-discharge of batteries and enhance safety. However, for the sake of brevity, the following embodiments will use a vehicle as an example of an electrical device for illustration.

[0080] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 100 is installed inside the vehicle 1000, and the battery device 100 can 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. 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, to meet the power needs of the vehicle 1000 during starting, navigation, and driving.

[0081] 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.

[0082] Please refer to Figure 2 , Figure 2 This is an exploded structural diagram of a battery provided in some embodiments of this application.

[0083] The battery device 100 mentioned in the embodiments of this application may include one or more battery cell assemblies 10 for providing voltage and capacity. The battery cell assembly 10 may include multiple battery cells 11, which are connected in series, parallel, or mixed connection via a busbar.

[0084] In some embodiments, the battery cell assembly 10 is typically formed by arranging a plurality of battery cells 11.

[0085] As an example, the battery cell assembly 10 can be a battery module, which is formed by arranging and fixing multiple battery cells 11 together to form an independent module. As an example, the battery module can be formed by bundling multiple battery cells 11 together with cable ties.

[0086] In some embodiments, such as Figure 2 As shown, the battery device 100 can be a battery pack, which includes a housing 20 and one or more individual battery cells 10, with the individual battery cells 10 housed within the housing 20. The housing 20 can be a simple three-dimensional structure such as a single cuboid, cylinder, or sphere, or a complex three-dimensional structure composed of combinations of simple cuboids, cylinders, or spheres. The material of the housing 20 can be an alloy such as aluminum alloy or iron alloy, a polymer such as polycarbonate or polyisocyanurate foam, or a composite material such as glass fiber and epoxy resin.

[0087] As an example, the battery cell assembly 10 can be a battery module, and the battery cell assembly 10 can be housed in the housing 20 by fixing the battery module in the housing 20.

[0088] As an example, the battery cell assembly 10 can also be housed in the housing 20 by directly fixing multiple battery cells 11 to the housing 20.

[0089] As an example, the housing 20 may include a first part 21 and a second part 22. The first part 21 and the second part 22 are fastened together to form a closed space inside the housing 20 to house the battery cell assembly 10. Here, "closed" refers to covering or closing, and can be either non-sealed or sealed to prevent liquids or other foreign objects from affecting the charging or discharging of the battery cell 11. The first part 21 may be a top cover or a bottom plate.

[0090] As an example, the housing 20 may include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that the interior of the housing 20 forms an enclosed space to house the battery cell assembly 10.

[0091] In some embodiments, the housing 20 may be part of the vehicle's chassis structure. For example, a portion of the housing 20 may be at least a portion of the vehicle's floor, or a portion of the housing 20 may be at least a portion of the vehicle's crossbeams and longitudinal beams.

[0092] The battery cell 11 provided in the embodiments of this application can be a secondary battery. A secondary battery refers to a battery cell 11 that can be used again after being discharged by recharging to activate the active material.

[0093] The battery cell 11 can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0094] Figure 3 This is an exploded structural diagram of a battery cell provided in some embodiments of this application. Figure 4 This is a schematic diagram of the structure of the end cap assembly according to some embodiments of this application. Figure 5 for Figure 4 An explosion diagram is shown. Please refer to... Figures 3 to 5 The battery cell 11 refers to the smallest unit that makes up a battery. For example... Figure 3 The battery cell 11 includes an end cap assembly 30, a housing 13, an electrode assembly 14, and other functional components.

[0095] End cap assembly 30 refers to a component that covers the opening of housing 13 to isolate the internal environment of battery cell 11 from the external environment. Not limited to this, the shape of end cap assembly 30 may be adapted to the shape of housing 13 to fit housing 13.

[0096] The end cap assembly 30 may include an end cap 12. In some embodiments, the end cap 12 may be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 12 is less prone to deformation under compression and impact, allowing the battery cell 11 to have higher structural strength and improved safety performance. Functional components such as electrode terminals may be provided on the end cap 12. The electrode terminals can be used for electrical connection with the electrode assembly 14 to output or input electrical energy to the battery cell 11. In some embodiments, such as... Figure 5As shown, the electrode terminals may include a positive electrode post 32 and a negative electrode post 33. The positive electrode post 32 may have an insulating member 15 and an end cap 12 passing through it, and be connected to a positive electrode riveting block 34 outside the end cap 12. The positive electrode riveting block 34 may be made of a conductive material, such as copper or aluminum. A positive electrode insulating member 36 may be provided between the positive electrode riveting block 34 and the end cap 12 to isolate the end cap 12 and the positive electrode riveting block 34, so that they are not conductive. Similarly, the negative electrode post 33 may have an insulating member 15 and an end cap 12 passing through it, and be connected to a negative electrode riveting block 35 outside the end cap 12. The negative electrode riveting block 35 may be made of a conductive material, such as copper or aluminum. A negative electrode insulating member 37 may be provided between the negative electrode riveting block 35 and the end cap 12 to isolate the end cap 12 and the negative electrode riveting block 35, so that they are not conductive. In other embodiments, the end cap 12 may not have a positive and negative riveting block, i.e., a minimalist end cap design is adopted.

[0097] In some embodiments, the end cap 12 may also be provided with a pressure relief mechanism, such as a pressure relief element 31 and an explosion-proof plate 38, for releasing internal pressure when the internal pressure or temperature of the battery cell 11 reaches a threshold. The pressure relief element 31 may be an explosion-proof valve.

[0098] The end cap 12 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. In some embodiments, an insulating member 15 can be provided on the inner side of the end cap 12. The insulating member 15 can be used to isolate the electrical connection components in the housing 13 from the end cap 12 to reduce the risk of short circuit. For example, the insulating member 15 can be plastic, rubber, etc.

[0099] The housing 13 is a component used to cooperate with the end cap 12 to form the internal environment of the battery cell 11, wherein the formed internal environment can accommodate the electrode assembly 14, electrolyte, and other components. The housing 13 and the end cap 12 can be independent components, with an opening 16 provided at one end of the housing 13 along a first direction X. The end cap 12 closes the opening 16 to form the internal environment of the battery cell 11. Alternatively, the end cap 12 and the housing 13 can be integrated. Specifically, the end cap 12 and the housing 13 can form a common connecting surface before other components are inserted into the housing, and the end cap 12 closes the housing 13 when it is necessary to encapsulate the interior. The housing 13 can have various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 13 can be determined according to the specific shape and size of the electrode assembly 14. The housing 13 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0100] Electrode assembly 14 is the component in the battery cell 11 where the electrochemical reaction takes place. The housing 13 may contain one or more electrode assemblies 14. Electrode assembly 14 is mainly formed by winding and forming positive and negative electrode plates, and a separator is typically provided between the positive and negative electrode plates. The portions of the positive and negative electrode plates containing active material constitute the main body of the electrode assembly.

[0101] Figure 6 for Figure 4 Schematic diagram of the middle end cap and insulating components. Figure 7 for Figure 4 The bottom view, Figure 8 for Figure 7 Sectional view at point BB. Figure 9 for Figure 6 Schematic diagram of the structure of the insulating component. Figure 10 for Figure 9 Top view.

[0102] Please refer to Figure 3 , Figures 6 to 10 This application provides a battery cell 11 including: a housing 13, an electrode assembly 14, and an end cap assembly 30. The housing 13 has an opening 16 at one end along a first direction X; the electrode assembly 14 is housed in the housing 13; the end cap assembly 30 includes an end cap 12 and an insulating member 15. The end cap 12 covers the opening 16, and the insulating member 15 is disposed on the side of the end cap 12 facing the electrode assembly 14. The insulating member 15 has a first surface 111 facing the electrode assembly 14. The first surface 111 has first protrusions 120 at both ends along a second direction Y. The first protrusions 120 have a first groove 130 on a second surface 112 away from the first surface 111. The first groove 130 extends along the second direction Y and is located at the position where the first protrusion 120 intersects with the first center plane A of the electrode assembly 14.

[0103] The first center plane A is a plane that passes through the center of the electrode assembly 14 and is perpendicular to the third direction Z. The first direction X, the second direction Y and the third direction Z are perpendicular to each other.

[0104] In this embodiment, the battery cell 11 includes an electrode assembly 14, a housing 13, and an end cap assembly 30. The electrode assembly 14 can be manufactured by a winding process or by stacking. It is understood that the multiple layers formed by stacking are prone to misalignment, and improvements can be made using the embodiments of this application. For ease of explanation, the following uses the winding formation of the electrode assembly 14 as an example.

[0105] The housing 13 may have an opening 16 at one end along the first direction X, through which the electrode assembly 14 can be installed into the housing 13. The end cap assembly 30 may include an insulator 15 and an end cap 12. The end cap 12 closes onto the opening of the housing 13 to isolate the internal environment of the battery cell 11 from the external environment. The end cap 12 may be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 12 is not easily deformed under compression and impact, enabling the battery cell 11 to have higher structural strength and improved safety performance.

[0106] The insulating element 15 can be disposed on the inner side of the end cover 12 facing the electrode assembly 14. It can insulate the end cover 12 and the electrical connection components inside the housing 13. At the same time, the insulating element 15 can also support the electrode assembly 14 and prevent the electrode assembly 14 from shaking inside the housing 13.

[0107] Understandable. Figure 3 The battery cell 11 shown in the diagram has its opening 16 facing upwards, indicating that the battery cell 11 is in an upright position. However, if... Figure 3 When the top and bottom are reversed, with the opening 16 facing down, the battery cell 11 is in an inverted state. It can be understood that in the inverted state, the insulating component 15 still needs to bear the weight of the electrode assembly 14, that is, the interaction force between the insulating component 15 and the electrode assembly 14 is greater than in the upright state.

[0108] like Figure 3 As shown, the first direction X can be the height direction of the battery cell 11, the second direction Y can be the length direction of the battery cell 11, and the third direction Z can be the width direction of the battery cell 11. The first direction X, the second direction Y, and the third direction Z are perpendicular to each other.

[0109] The first center plane A of the electrode assembly 14 can be a plane perpendicular to the width direction of the battery cell 11 and passes through the geometric center of the electrode assembly 14. It can be understood that the electrode assembly 14 can be symmetrically arranged about the first center plane A.

[0110] It is understood that a single battery cell 11 may contain one or more electrode assemblies 14 (such as...). Figure 3 The device has two electrode assemblies 14, and multiple electrode assemblies 14 can be arranged along a third direction Z, with each electrode assembly 14 having a first central plane A. Figure 3 Only the first center surface A of the electrode assembly 14 located on the front side is shown.

[0111] Please refer to Figures 6 to 10 The insulating member 15 has a first surface 111 facing the electrode assembly 14, and the first surface 111 is the surface of the insulating member 15 facing the interior of the housing 13. It can be understood that, in the upright state, the first surface can be the lower surface of the insulating member 15 (e.g., the lower surface of the insulating member 15). Figure 6 In the inverted state, the first surface 111 can be the upper surface of the insulating element 15 (e.g., Figure 9 ).

[0112] Two first bosses 120 may protrude from the first surface 111 of the insulating member 15, and the two first bosses 120 may be respectively disposed at both ends of the insulating member 15 along the second direction Y. The first bosses 120 may be strip-shaped bosses extending along the third direction Z to increase the support for the electrode assembly 14. It is understood that the first bosses 120 have a second surface 112 facing away from the first surface 111, and the second surface 112 may also face the electrode assembly 14, that is, the second surface 112 also faces the interior of the housing 13. It is understood that the second surface 112 may contact the electrode assembly 14 to provide support and insulation.

[0113] Figure 11 for Figure 10 Left view, Figure 12 for Figure 11 Please refer to the enlarged diagram at point C. Figure 7 , Figure 9 , Figure 10 , Figure 11 and Figure 12 A first groove 130 may be provided on the second surface 112. The first groove 130 may extend along the second direction Y. It can be understood that in this embodiment, the first groove 130 may not penetrate the first boss 120, or it may penetrate the first boss 120.

[0114] like Figure 7 As shown, the first center surface A is represented by a dashed line A in this view, and the first groove 130 can be set corresponding to the first center surface A. It can be understood that by extending the first center surface A to intersect with the second surface 112 of the first boss 120, a line segment can be obtained on the second surface 112, and the first groove 130 can be set at the position of this line segment, that is, the first groove 130 is set at the position where the first boss 120 intersects with the first center surface A.

[0115] The shape of the first groove 130 can be varied, for example... Figure 12 In this context, taking the section perpendicular to the second direction as the longitudinal section, the longitudinal cross-sectional area of ​​the first groove 130 gradually decreases from the second surface 112 towards the direction away from the second surface 112. In some embodiments, the longitudinal cross-sectional area can gradually decrease to form a sharp corner, such as... Figure 12 In the middle, the longitudinal section is triangular, which simplifies the processing difficulty and allows only a small amount of material to be removed from the first boss 120 to obtain the first groove 130, thereby improving the structural strength of the first boss 120 and increasing its support.

[0116] Of course, in other embodiments, the longitudinal cross-sectional shape of the first groove 130 can also be square, trapezoidal, or other shapes.

[0117] It is understandable that the electrode sheet of a wound electrode assembly typically includes a large, roughly planar area and bending areas on both sides of the large area. Through research, the inventors discovered that areas with more severe helical misalignment usually appear at both ends of the electrode assembly 14 along the first direction X. Figure 3 The position where the upper and lower end faces intersect with the first center face A. It can be understood that the portion of the electrode at the spiral misalignment point will be higher than the original wound end face, making it easily damaged. For example... Figure 3 As shown, the area with more severe spiral misalignment is located at the center line L at the upper end of the electrode assembly 14 (an inner electrode assembly, not shown on the first center surface). That is, the center line L is the position where the upper end of the electrode plate of the electrode assembly 14 intersects with the first center surface A.

[0118] The first groove 130 can be set to correspond to the center line L, so that a clearance can be set in the place where the electrode plate of the electrode assembly is severely misaligned. Under bumpy vibration or inverted state, the first boss 120 can not contact the electrode assembly 14 at the first groove 130 position, that is, reduce the compression between the part of the electrode assembly 14 with severe spiral misalignment and the insulating part 15, and realize the clearance design.

[0119] In this embodiment, by setting a first groove at the intersection of the first center surface and the first protrusion of the electrode assembly, a groove design (first groove) can be made on the insulating part opposite to the electrode plate at the position where the electrode plate is prone to spiral misalignment and protrusion. This can reduce the mutual squeezing stress between the electrode plate and the insulating part, improve the situation where the electrode plate is easily damaged by pressure, reduce the situation where the negative electrode coating material is wrinkled and deformed and burrs are generated, thereby improving the self-discharge problem of the battery cell caused by the separator being punctured. At the same time, it can also improve the thermal runaway problem caused by internal short circuit, and improve the safety of the battery cell.

[0120] In some embodiments, the first groove 130 extends through the first boss 120 along the second direction Y.

[0121] In this embodiment, as Figure 7 As shown, the first groove 130 passes through the first boss 120 at both ends along the second direction Y. That is, the first groove 130 can be a through groove extending along the second direction Y.

[0122] Since the first groove 130 penetrates the first boss 120, that is, the first groove 130 can cover the entire intersection of the first center surface and the first boss, the groove design (first groove) can be carried out to a greater extent in the position where the electrode is prone to spiral misalignment and protrusion, which further reduces the mutual squeezing force between the electrode and the insulating part and improves the situation where the electrode is easily damaged by pressure.

[0123] According to some embodiments of this application, please refer to Figure 12 The groove wall of the first groove 130 and the second surface 112 have a rounded transition.

[0124] It is understandable that the first groove 130 and the second surface 112 can achieve a rounded transition through methods such as rounding corners, that is, the transition between the two can be relatively smooth without forming sharp edges or corners. Figure 12 In the first groove 130, there are two opposing groove walls, and each groove wall can be rounded to the second surface 112.

[0125] The size of the rounded corner can be set according to the actual size of the groove.

[0126] In this embodiment, by providing a rounded transition between the groove wall of the first groove 130 and the second surface 112, it is possible to avoid the formation of sharp corners that are prone to stress concentration between the two. This can improve the problem of secondary damage to the electrode sheet caused by local stress concentration at the contact surface between the electrode assembly 14 and the first boss 120, and further improve the situation where the electrode sheet of the electrode assembly is crushed.

[0127] Based on some embodiments of this application, continue to refer to Figure 12 The depth H1 of the first groove 130 along the first direction X satisfies: 0.5mm≤H1≤1mm.

[0128] It can be understood that the depth H1 of the first groove 130 can be the distance between the bottom of the first groove 130 and the second surface 112. In some embodiments, H1 can be 0.5mm, 0.52mm, 0.54mm, 0.56mm, 0.58mm, 0.6mm, 0.62mm, 0.64mm, 0.66mm, 0.68mm, 0.7mm, 0.72mm, 0.74mm, 0.76mm, 0.78mm, 0.8mm, 0.82mm, 0.84mm, 0.86mm, 0.88mm, 0.9mm, 0.92mm, 0.94mm, 0.96mm, 0.98mm, and 1mm, etc.

[0129] In some embodiments, the width W of the first groove 130 in the third direction Z may also satisfy 0 < W ≤ 2 mm. Further, 0.2 mm ≤ W ≤ 1 mm. More specifically, 0.5 mm ≤ W ≤ 1 mm. For example, the width W of the first groove may be 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm, 0.75 mm, 0.8 mm, 0.85 mm, 0.9 mm, 0.95 mm, 1 mm, and so on. By setting the value range of the width of the first groove 130, the width of the first groove will not be too wide, so as not to significantly reduce the contact area between the electrode assembly 14 and the insulating member 15. The width of the first groove will not be too small, and it can also avoid the positions that are prone to being crushed as much as possible.

[0130] By setting the depth of the first groove to be not less than 0.5 mm, the avoidance design of the positions with serious spiral dislocation can be effectively realized, and the problem of the pole piece being crushed can be alleviated. At the same time, by setting the depth of the first groove to be not higher than 1 mm, an overly deep groove will not be formed on the first boss, thereby reducing the influence of grooving on the strength of the first boss, and further enabling the insulating member to have sufficient support strength.

[0131] Figure 13 The structural schematic diagram of the insulating member provided by some embodiments of the present application. Continue to refer to Figure 3 、 Figure 10 和 Figure 13 According to some embodiments of the present application, the battery cell 11 includes one or a plurality of electrode assemblies 14 arranged along the third direction Z. First grooves 130 are provided at each position where the first boss 120 intersects the first central plane A of each electrode assembly 14 of the battery cell 11.

[0132] In this embodiment, the battery cell 11 may have one electrode assembly 14. At this time, a first groove 130 may be provided at each position where each first boss 120 intersects the first central plane A of the first electrode assembly 14.

[0133] In other embodiments, the battery cell 11 may further include a plurality of electrode assemblies 14, such as Figure 3 shows two electrode assemblies 14. These two electrode assemblies 14 may be arranged in the housing 13 along the third direction. In addition, such as Figure 10 和 Figure 13 These two electrode assemblies 14 respectively have a first central plane A. Each first boss 120 has one intersection position with a first central plane A. That is, the two electrode assemblies 14 and each first boss 120 have two intersection positions. For example, Figure 10 the two first grooves 130 on the left side in

[0134] It is understood that this embodiment takes the battery cell 11 as having two electrode assemblies 14 as an example. In other embodiments, the battery cell 11 may have more, such as three, four, five, six electrode assemblies, etc. A first groove 130 may be provided at the position where the first center surface A of each electrode assembly intersects with the first protrusion 120.

[0135] In this embodiment, by providing a first groove at the intersection of each electrode assembly and the first protrusion, the design can avoid the easily crushed positions of each electrode assembly, so that the parts of each electrode assembly with severe spiral misalignment have a lower risk of extrusion deformation, reducing the risk of the electrode sheet being crushed, thereby further improving the self-discharge problem of the battery cell caused by the separator being punctured, and also further improving the thermal runaway problem caused by internal short circuit, thus improving the safety of the battery cell.

[0136] According to some embodiments of this application, please refer to Figure 9 , Figure 10 and Figure 13 The second surface 112 is also provided with a second groove 140, which extends along the third direction Z. The second groove is located inside the first boss facing another first boss, and the second groove 140 also penetrates the inside of the first boss 120 in the direction facing another first boss 120.

[0137] by Figure 10 Taking the first protrusion 120 on the left side as an example, the second surface 112 of the first protrusion 120 is provided with a second groove 140, which can be formed by recessing the second surface 112 along the first direction X. It can be understood that the second groove 140 extends along the third direction Z in a long strip-like structure, and its two ends in the third direction Z do not necessarily penetrate the first protrusion 120, such as... Figure 10 The second groove 140 may also have a portion of the first protrusion at each end along the third direction, so as not to reduce the contact area between the first protrusion and the electrode assembly too much.

[0138] The second groove 140 can be located inside the first boss 120 (the left first boss) facing the other first boss (the right first boss). Furthermore, its end facing the other first boss can also penetrate through the inside of the first boss 120. Figure 10 In the middle, the right side of the second groove 140 may also have an open opening.

[0139] Understandably, after relevant research, the inventors also discovered that the inner side (inner ring) of the bending area of ​​the wound electrode assembly is also prone to spiral misalignment and protrusion, and it may also be subject to mutual force and compression with the insulating component.

[0140] By providing a second groove 140 on the inner side of the first protrusion, the second groove 140 can correspond to the inner side of the bending area of ​​the electrode assembly 14, thereby improving the situation where the electrode sheet inside the bending area is easily damaged by pressure, thus improving the self-discharge problem caused by the separator being punctured in the battery cell, and also improving the thermal runaway problem caused by internal short circuit, thereby improving the safety of the battery cell.

[0141] In some embodiments, such as Figure 13 As shown, the first boss 120 has a first support portion 143 located at both ends of the second groove 140 along the third direction Z.

[0142] In this embodiment, the second groove 140 extends along the third direction Z without penetrating both ends of the first boss 120. That is, the first boss 120 has first support portions 143 located at both ends of the second groove 140 along the third direction Z. The first support portions 143 can contact the electrode assembly 14, thereby providing support for it.

[0143] The first support portions 143 at both ends of the second groove 140 can support the electrode assembly 14, thereby improving the phenomenon that the electrode sheet inside the bending area is easily damaged by pressure as much as possible without excessively reducing the support of the first boss 120 on the electrode assembly 14.

[0144] According to some embodiments of this application, such as Figure 10 and Figure 13 The second groove 140 has a first sidewall 141 perpendicular to the second direction Y. The battery cell 11 includes one or a plurality of electrode assemblies 14 arranged along the third direction Z. The first center plane A of each electrode assembly 14 of the battery cell 11 is projected onto the plane where the first sidewall 141 is located within the first sidewall 141.

[0145] The first sidewall 141 can be arranged perpendicular to the second direction Y, and the first sidewall 141 can extend along the third direction Z. It can be understood that the dimension of the first sidewall 141 extending along the third direction Z (the dimension of the second groove 140 along the third direction Z) can be determined according to the position of the first center surface A of each electrode assembly 14.

[0146] When the battery cell 11 includes an electrode assembly, the orthographic projection of the first center plane A of the electrode assembly onto the plane where the first sidewall 141 is located can be a line segment, which is located within the first sidewall 141.

[0147] When the battery cell 11 includes multiple electrode assemblies, Figure 10 and Figure 13Taking two examples, the orthographic projection of the two first center planes A of the two electrode assemblies 14 onto the plane where the first sidewall 141 is located is two parallel line segments, and these two line segments are also located within the first sidewall 141.

[0148] In other words, the second groove 140 can extend along the third direction Z to the first center surface A passing through all electrode assemblies. It can be understood that the closer to the first center surface A, the more severe the helical misalignment is on the inner side of the bending area of ​​each electrode assembly.

[0149] The second groove 140 extends along a third direction to cover the first center surface of each electrode assembly, so that the second groove can effectively avoid the inner side of the bending area of ​​the electrode assembly, thereby further improving the situation that the electrode sheet inside the bending area is easily damaged by pressure, improving the self-discharge problem caused by the separator being punctured in the battery cell, and also improving the thermal runaway problem caused by internal short circuit, thus improving the safety of the battery cell.

[0150] According to some embodiments of this application, please refer to Figure 9 and Figure 10 The first boss 120 is connected to the inner side of the other first boss 120 by a second boss 150. The second boss 150 is disposed on the first surface 111, and the height D1 of the first boss 120 protruding from the first surface 111 and the height D2 of the second boss 150 protruding from the first surface 111 satisfy: D1>D2; the depth H2 of the second groove 140 along the first direction X satisfies: H2=D1-D2.

[0151] A second boss 150 may be provided on the inner side of the first boss 120. Both the first boss 120 and the second boss 150 protrude from the first surface 111, and the first boss 120 protrudes higher. The second boss 150 may be connected to the first boss 120, for example, the two may be integrally formed.

[0152] Figure 9 In the first boss 120, the height of the first boss 120 protruding from the first surface 111 is D1, and the height of the second boss 150 protruding from the first surface 111 is D2. The depth of the second groove 140 along the first direction X is H2.

[0153] It can be understood that H2 = D2 - D1 means that the bottom wall plane 142 of the second groove 140 facing the electrode assembly 14 is flush with the third surface 151 of the second boss 150, which is away from the first surface 111. That is to say, the second groove 140 can extend from the second surface 112 to the third surface 151.

[0154] In this embodiment, by setting a second boss that is connected to the first boss, the strength of the first boss can be enhanced. At the same time, by setting the depth of the second groove 140 to the difference between the height of the first boss and the height of the second boss, the structural complexity can be reduced, making the processing more convenient and reducing costs.

[0155] According to some embodiments of this application, the groove wall of the second groove 140 and the second surface 112 have a rounded transition.

[0156] It is understandable that the second groove 140 and the second surface 112 can achieve a rounded transition through methods such as rounding corners, that is, the transition between the two can be relatively smooth without forming sharp edges or corners. Figure 10 In the second groove 140, there are three sidewalls: a first sidewall 141 and two sidewalls opposite each other along the third direction. It can be understood that each sidewall can have a rounded transition with the second surface 112.

[0157] The size of the fillet can be set according to the actual size of the groove. The size of the transition fillet between the second groove 140 and the second surface 112 can be the same as or different from the size of the transition fillet between the first groove 130 and the second surface 112, depending on the actual situation.

[0158] In this embodiment, by providing a rounded transition between the groove wall of the second groove 140 and the second surface 112, it is possible to avoid the formation of sharp corners that are prone to stress concentration between the two. This can improve the problem of secondary damage to the electrode sheet caused by local stress concentration at the contact surface between the electrode assembly 14 and the first boss 120, and further improve the situation where the electrode sheet of the electrode assembly is crushed.

[0159] According to some embodiments of this application, such as Figure 10 As shown, the dimension H3 of the second groove 140 along the second direction Y satisfies: 2mm≤H3≤4mm.

[0160] It is understandable that the size H3 of the second groove 140 can be 2mm, 2.2mm, 2.4mm, 2.6mm, 2.8mm, 3mm, 3.2mm, 3.4mm, 3.6mm, 3.8mm and 4mm, etc.

[0161] By setting the range of the second groove size H3, the second groove size H3 can be made not to exceed 4mm, so as not to significantly reduce the contact area between the electrode assembly 14 and the insulating member 15, so that the insulating member can effectively support the electrode assembly. At the same time, the second groove size H3 is not less than 2mm, which can also avoid the position that is prone to crushing as much as possible.

[0162] According to some embodiments of this application, such as Figure 13The second surface 112 is also provided with a third groove 160. The third groove 160 extends along the third direction Z. The third groove 160 is located on the outside of the first boss 120 away from the other first boss 120, and the third groove 160 also penetrates the outside of the first boss 120 in the direction away from the other first boss 120.

[0163] by Figure 13 Taking the first protrusion 120 on the left side (the first protrusion on the right side is not shown) as an example, the second surface 112 of the first protrusion 120 is provided with a third groove 160. The third groove 160 can be formed by recessing the second surface 112 along the first direction X. It can be understood that the third groove 160 extends along the third direction Z in a long strip-like structure, and its two ends in the third direction Z do not necessarily penetrate the first protrusion 120, such as... Figure 13 The second groove 140 may also have a portion of the first protrusion at each end along the third direction, so as not to reduce the contact area between the first protrusion and the electrode assembly too much.

[0164] The third groove 160 can be located on the outer side of the first boss 120 (the first boss on the left) away from the other first boss (the first boss on the right). Furthermore, the end of the groove away from the other first boss can also penetrate through the outer side of the first boss 120. Figure 13 In the middle, the left side of the third groove 160 may also have an open opening.

[0165] Understandably, after relevant research, the inventors also discovered that the outer side (outer ring) of the bending area of ​​the wound electrode assembly is also prone to spiral misalignment and protrusion, and it may also be subject to mutual force and compression with the insulating component.

[0166] By providing a third groove 160 on the outer side of the first protrusion, which corresponds to the outer side of the bending area of ​​the electrode assembly 14, the situation where the electrode sheet on the outer side of the bending area is easily damaged can be improved, thereby improving the self-discharge problem caused by the separator being punctured in the battery cell. At the same time, it can also improve the thermal runaway problem caused by internal short circuit, thus improving the safety of the battery cell.

[0167] In some embodiments, such as Figure 13 As shown, the first boss 120 has a first support portion 144 located at both ends of the third groove 160 along the third direction Z.

[0168] In this embodiment, the third groove 160 extends along the third direction Z without penetrating both ends of the first boss 120. That is, the first boss 120 has second support portions 144 located at both ends of the third groove 160 along the third direction Z. The second support portions 144 can contact the electrode assembly 14, thereby providing support for it.

[0169] The second support portions 144 at both ends of the third groove 160 can support the electrode assembly 14, thereby improving the phenomenon that the electrode sheet on the outside of the bending area is easily damaged by pressure as much as possible without excessively reducing the support of the first boss 120 on the electrode assembly 14.

[0170] According to some embodiments of this application, such as Figure 13 As shown, the third groove 160 has a second sidewall 161 perpendicular to the second direction Y. The battery cell 11 includes one or a plurality of electrode assemblies 14 arranged along the third direction Z. The first center plane A of each electrode assembly 14 of the battery cell 11 is projected onto the plane where the second sidewall 161 is located within the second sidewall 161.

[0171] The second sidewall 161 can be arranged perpendicular to the second direction Y, and the second sidewall 161 can extend along the third direction Z. It can be understood that the dimension of the second sidewall 161 extending along the third direction Z (the dimension of the third groove 160 along the third direction Z) can be determined according to the position of the first center surface A of each electrode assembly 14.

[0172] When the battery cell 11 includes an electrode assembly, the orthographic projection of the first center plane A of the electrode assembly onto the plane where the second sidewall 161 is located can be a line segment, which is located within the second sidewall 161.

[0173] When the battery cell 11 includes multiple electrode assemblies, Figure 13 Taking two examples, the orthographic projection of the two first center planes A of the two electrode assemblies 14 onto the plane where the second sidewall 161 is located is two parallel line segments, and these two line segments are also located within the second sidewall 161.

[0174] In other words, the third groove 160 can extend along the third direction Z to the first center surface A passing through all electrode assemblies. It can be understood that the closer to the first center surface A on the outer side of the bending area of ​​each electrode assembly, the more severe the helical misalignment.

[0175] The third groove 160 extends along a third direction to cover the first center surface of each electrode assembly, so that the third groove can effectively avoid the outer side of the bending area of ​​the electrode assembly, thereby further improving the situation where the electrode sheet on the outer side of the bending area is easily damaged by pressure, improving the self-discharge problem caused by the separator being punctured in the battery cell, and also improving the thermal runaway problem caused by internal short circuit, thus improving the safety of the battery cell.

[0176] According to some embodiments of this application, the groove wall of the third groove 160 and the second surface 112 have a rounded transition.

[0177] It is understandable that the third groove 160 and the second surface 112 can achieve a rounded transition through methods such as rounding corners, that is, the transition between the two can be relatively smooth without forming sharp edges or corners. Figure 13 In the third groove 160, there are three sidewalls: a second sidewall 161 and two sidewalls opposite each other along the third direction. It can be understood that each sidewall can have a rounded transition with the second surface 112.

[0178] The size of the fillet can be set according to the actual size of the groove. The sizes of the transition fillets between the third groove 160 and the second surface 112, the second groove 140 and the second surface 112, and the first groove 130 and the second surface 112 can be the same or different, depending on the actual situation.

[0179] In this embodiment, by providing a rounded transition between the groove wall of the third groove 160 and the second surface 112, it is possible to avoid the formation of sharp corners that are prone to stress concentration between the two. This can improve the problem of secondary damage to the electrode sheet caused by local stress concentration at the contact surface between the electrode assembly 14 and the first boss 120, and further improve the situation where the electrode sheet of the electrode assembly is crushed.

[0180] According to some embodiments of this application, please refer to Figure 5 , Figure 9 , Figure 10 and Figure 13 The end cap assembly 30 further includes: a pressure relief member 31, which is disposed on the end cap 12; the first surface 111 is also provided with a third protrusion 170, the orthographic projection of the third protrusion 170 on the first surface 111 at least partially coincides with the orthographic projection of the pressure relief member 31 on the first surface 111, the third protrusion 170 is located between the two first protrusions 120, and the height D3 of the third protrusion 170 protruding from the first surface 111 and the height D1 of the first protrusion 120 protruding from the first surface satisfy: D1≥D3.

[0181] The pressure relief component 31 can be a pressure relief mechanism that releases internal pressure when the internal pressure or temperature of the battery cell 11 reaches a threshold, and it can be installed on the end cover.

[0182] The third protrusion 170 can protrude from the first surface 111 and can be located between the two first protrusions 120, for example, at the center of the two first protrusions. The orthographic projection of the third protrusion 170 on the first surface 111 and the orthographic projection of the pressure relief member 31 on the first surface at least partially coincide, that is, the third protrusion 170 can be provided corresponding to the pressure relief member 31. In some embodiments, the third protrusion 170 can be provided with a pressure relief hole or other structure that can connect the pressure relief member 31 with the interior of the battery cell.

[0183] The third protrusion 170 can extend in the X direction along the third side in an elongated shape. The height D3 of the third protrusion 170 protruding from the first surface 111 can be equal to the height D1 of the first protrusion 120, or D3 can be slightly less than the height D1 of the first protrusion 120.

[0184] By setting a third protrusion, the electrode assembly can be further supported, making the electrode assembly more effective.

[0185] According to some embodiments of this application, please refer to Figure 9 and Figure 13 The height D3 of the third boss 170 protruding from the first surface 111 is equal to the height D1 of the first boss 120 protruding from the first surface 111; the third boss 170 is provided with a fourth groove 180 on a fourth surface 171 away from the first surface 111; the fourth groove 180 penetrates the third boss along the second direction Y, and the fourth groove 180 has a first bottom wall 181 perpendicular to the first direction X, and the orthographic projection of the first center plane A of the electrode assembly 14 on the plane where the first bottom wall 181 is located is located within the first bottom wall 181.

[0186] When the height of the third boss 170 is equal to that of the first boss 120, the fourth surface 171 of the third boss 170, which is away from the first surface 111, can also be slotted to form a fourth groove 180. The two ends of the fourth groove 180 along the second direction Y can penetrate the third boss 170, thereby forming a through groove.

[0187] The fourth groove 180 may have a first bottom wall 181 perpendicular to the first direction X, and the first bottom wall 181 may extend into an elongated shape along the third direction Z. It can be understood that the dimension of the first bottom wall 181 extending along the third direction Z (the dimension of the fourth groove 180 along the third direction Z) can be determined according to the position of the first center plane A of each electrode assembly 14.

[0188] When the battery cell 11 includes an electrode assembly, the orthographic projection of the first center plane A of the electrode assembly onto the plane where the first bottom wall 181 is located can be a line segment, which is located within the first bottom wall 181.

[0189] When the battery cell 11 includes multiple electrode assemblies, Figure 13 Taking two examples, the orthographic projection of the two first center planes A of the two electrode assemblies 14 onto the plane where the first bottom wall 181 is located is two parallel line segments, and these two line segments are also located within the first bottom wall 181.

[0190] In other words, the fourth groove 180 can extend along the third direction Z to the first center surface A that passes through all electrode assemblies. It can be understood that, as mentioned above, the position where the end face of the electrode plate of the electrode assembly 14 intersects with the first center surface A (at the center line L) is prone to severe spiral misalignment, that is, the electrode plate at this position is more likely to be crushed.

[0191] The fourth groove 180 extends along a third direction to cover the first center surface of each electrode assembly, so that the fourth groove can effectively avoid the position of the first center surface of the electrode assembly, thereby further improving the situation where the electrode sheet in this area is easily damaged by pressure, thereby improving the self-discharge problem caused by the separator being punctured in the battery cell, and also improving the thermal runaway problem caused by internal short circuit, thus improving the safety of the battery cell.

[0192] In some embodiments, such as Figure 10 The two first protrusions 120 are symmetrically arranged about the second center plane E, which is a plane passing through the center of the insulating member 15 and perpendicular to the second direction Y. The two first protrusions 120 can be symmetrically arranged about the second center plane E, that is, each first protrusion 120 can be provided with a first groove 130, a second groove 140 and a third groove 160, so as to further improve the situation where the electrode sheet is easily damaged by pressure.

[0193] It is understood that this embodiment uses structural optimization to prevent interference between the electrode and the insulating component. It is also understood that the main failure locations of the electrode formed after the electrode assembly is wound are at the center line L of its end face and the inner circle of the bending area.

[0194] Without minimizing the contact area between the insulating component and the electrode assembly, a groove is cut into the first protrusion of the insulating component to create structural clearance. This prevents the severely misaligned position of the electrode (the protruding part of the electrode) from contacting the first protrusion and causing damage to the electrode when the battery cell is inverted.

[0195] This application embodiment also provides a battery device 100, such as Figure 2 As shown, it includes the battery cell 11 in the above embodiments.

[0196] It is understood that the battery device 100 provided in this application, by using any of the aforementioned battery cells 11, has all the beneficial effects of the aforementioned battery cells 11, which will not be repeated here.

[0197] This application provides an electrical device, which includes the battery device 100 in the above embodiments, and the battery device 100 is used to provide electrical energy.

[0198] Electrical devices include vehicles (such as cars, electric vehicles, ships, spacecraft, etc.), display devices (such as mobile phones, tablets, laptops, etc.), electric toys, power tools, etc.

[0199] It is understood that the electrical device provided in this application, by using any of the aforementioned battery cells 11, has all the beneficial effects of the aforementioned battery cells 11, which will not be elaborated here.

[0200] This application provides an energy storage device, which includes the battery device 100 in the above embodiments, and the battery device 100 is used to store electrical energy.

[0201] Energy storage devices can include, but are not limited to, centralized energy storage devices (such as containerized energy storage devices), distributed energy storage devices, mobile energy storage devices, wearable energy storage devices, and so on.

[0202] It is understood that the energy storage device provided in this application, by using any of the aforementioned battery cells 11, has all the beneficial effects of the aforementioned battery cells 11, which will not be elaborated here.

[0203] In some embodiments, the battery cell 11 includes a housing 13, an electrode assembly 14, and an end cap assembly 30. The housing 13 has an opening 16 at one end along a first direction X; the electrode assembly 14 is housed in the housing 13; an insulating member 15 is connected to the opening 16 of the housing 13; the end cap assembly 30 includes the insulating member 15 and an end cap 12, the end cap 12 covering the opening 16; the insulating member 15 is disposed on the side of the end cap 12 facing the electrode assembly 14; the insulating member 15 has a first surface 111 facing the electrode assembly 14; the first surface 111 has first protrusions 120 for supporting the electrode assembly 14 at both ends along a second direction Y; the first protrusions 120 have a first groove 130 on a second surface 112 away from the first surface 111; the first groove 130 penetrates the first protrusion 120 along the second direction Y; and the first groove 130 is located at the position where the first protrusion 120 intersects with the first center plane A of the electrode assembly 14.

[0204] In addition, the second surface 112 is also provided with a second groove 140, which extends along a third direction Z. The second groove is located inside the first boss facing another first boss, and the second groove 140 also penetrates the inside of the first boss 120 in the direction facing another first boss 120. The first boss 120 has first support portions 143 located at both ends of the second groove 140 along the third direction Z.

[0205] In this embodiment, the housing 13 is provided with two electrode assemblies 14 arranged along the third direction Z. A first groove 130 is provided at the intersection of the first center surface A of each electrode assembly 14 and the first boss 120. Furthermore, the second groove 140 extends along the third direction Z so that it can pass through each of the first center surfaces A of the electrode assembly 14.

[0206] It is understandable that spiral misalignment is unavoidable during the winding process. This causes the electrode to bulge beyond its original end face at the center line L position, the inner ring of the bending zone, and the outer ring of the bending zone after winding. Especially in inverted applications, gravity exacerbates the bulging, making the electrode more susceptible to damage and causing burrs on the negative electrode coating material. During long-cycle vibration, relative movement between the electrodes can lead to wrinkling, and the burrs can puncture the electrodes.

[0207] In this embodiment, to improve this situation, second grooves 140 are formed on both sides of the first boss 120 of the insulating component perpendicular to the second direction Y, so that the insulating component structure is free from gaps and the inner ring electrode sheet of the winding area is not damaged. In addition, a through groove 130 can be formed on the first boss parallel to the second direction Y and located at the first center surface of each electrode assembly. The groove depth can be 0.5-1mm. The number of first grooves can be determined according to the number of electrode assemblies. In addition, the grooves on the left and right first bosses set along the second direction Y can be symmetrically arranged to improve the interference between the through protrusion of the electrode sheet in the middle part and the first boss, and improve the phenomenon of self-discharge of the electrode assembly caused by the electrode sheet being easily damaged. This improves the problem of low voltage of the battery cell due to self-discharge and the safety hazard of internal short circuit when self-discharge is severe.

[0208] It is understood that this embodiment does not significantly reduce the contact area between the electrode assembly and the insulating component, and the junction of each groove and the second surface 112 can be rounded to improve the secondary damage to the electrode sheet caused by local stress concentration at the contact surface between the electrode assembly and the insulating component. This further improves the electrode sheet crushing condition of the electrode assembly, prevents the electrode assembly from self-discharging and causing low voltage, or even thermal runaway caused by internal short circuit, and effectively improves the safety performance of the battery cell.

[0209] 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 in that, include: The housing has an opening at one end along a first direction; Electrode assembly, housed within the housing; An end cap assembly includes an end cap and an insulating member. The end cap covers the opening, and the insulating member is disposed on the side of the end cap facing the electrode assembly. The insulating member has a first surface facing the electrode assembly. The first surface has a first protrusion at each end along a second direction. The first protrusion has a first groove on a second surface away from the first surface. The first groove extends along the second direction and is located at the position where the first protrusion intersects with the first center surface of the electrode assembly. Wherein, the first center plane is a plane passing through the center of the electrode assembly and perpendicular to a third direction, and the first direction, the second direction and the third direction are perpendicular to each other.

2. The battery cell according to claim 1, characterized in that, The first groove extends through the first boss along the second direction.

3. The battery cell according to claim 1, characterized in that, The groove wall of the first groove and the second surface have a rounded transition.

4. The battery cell according to claim 1, characterized in that, The depth H1 of the first groove along the first direction satisfies: 1mm.

5. The battery cell according to claim 1, characterized in that, The battery cell includes one or more electrode assemblies arranged along the third direction, and the first groove is provided at each position where the first boss intersects with the first center plane of each electrode assembly of the battery cell.

6. The battery cell according to any one of claims 1-5, characterized in that, The second surface is further provided with a second groove, which extends along the third direction. The second groove is located inside the first boss facing another first boss, and the second groove also penetrates the inside of the first boss in the direction facing the other first boss.

7. The battery cell according to claim 6, characterized in that, The first boss has a first support portion located at both ends of the second groove along the third direction.

8. The battery cell according to claim 6, characterized in that, The second groove has a first sidewall perpendicular to the second direction, and the battery cell includes one or a plurality of electrode assemblies arranged along the third direction. The orthographic projections of the first center plane of each electrode assembly of the battery cell onto the plane containing the first sidewall are all located within the first sidewall.

9. The battery cell according to claim 6, characterized in that, A second boss is connected to the inner side of the first boss facing another first boss. The second boss is disposed on the first surface, and the height D1 of the first boss protruding from the first surface and the height D2 of the second boss protruding from the first surface satisfy: D1 ; The depth H2 of the second groove along the first direction satisfies: H2=D1-D2.

10. The battery cell according to claim 6, characterized in that, The groove wall of the second groove and the second surface have a rounded transition.

11. The battery cell according to claim 6, characterized in that, The dimension H3 of the second groove along the second direction satisfies: 4mm.

12. The battery cell according to any one of claims 1-5, characterized in that, The second surface is also provided with a third groove, which extends along the third direction. The third groove is located on the outside of the first boss away from the other first boss, and the third groove also penetrates the outside of the first boss in the direction away from the other first boss.

13. The battery cell according to claim 12, characterized in that, The first boss has a second support portion located at both ends of the third groove along the third direction.

14. The battery cell according to claim 12, characterized in that, The third groove has a second sidewall perpendicular to the second direction, and the battery cell includes one or a plurality of electrode assemblies arranged along the third direction. The orthographic projections of the first center plane of each electrode assembly of the battery cell onto the plane containing the second sidewall are all located within the second sidewall.

15. The battery cell according to claim 12, characterized in that, The groove wall of the third groove has a rounded transition with the second surface.

16. The battery cell according to any one of claims 1-5, characterized in that, The end cap assembly further includes: a pressure relief component, the pressure relief component being disposed on the end cap; The first surface is further provided with a third protrusion, which is located between the two first protrusions. The orthographic projection of the third protrusion on the first surface at least partially coincides with the orthographic projection of the pressure relief component on the first surface, and the height D3 of the third protrusion protruding from the first surface and the height D1 of the first protrusion protruding from the first surface satisfy: D1 .

17. The battery cell according to claim 16, characterized in that, The height D3 of the third boss protruding from the first surface is equal to the height D1 of the first boss protruding from the first surface; The third protrusion has a fourth groove on a fourth surface opposite to the first surface. The fourth groove penetrates the third protrusion along the second direction. The fourth groove has a first bottom wall perpendicular to the first direction. The orthographic projection of the first center plane of the electrode assembly onto the plane where the first bottom wall is located is located within the first bottom wall.

18. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-17.

19. An electrical appliance, characterized in that, The electrical device includes the battery device as described in claim 18, the battery device being used to provide electrical energy.

20. An energy storage device, characterized in that, The energy storage device includes the battery device as described in claim 18, the battery device being used to store electrical energy.

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