Battery case, battery cell, battery, method and apparatus for manufacturing a battery case

Abstract

To propose a battery case, a battery cell, a battery, and a method and a device for manufacturing a battery case, to improve battery performance.SOLUTION: There are provided a battery case, a battery cell (20), a battery (10), and a method and a device for manufacturing the battery case (21). The battery case (21) includes a pressure release region (213). The pressure release region (213) includes a first recessed groove (2131) provided on the inner surface of the battery case (21) and a second recessed groove (2132) provided on the outer surface of the battery case (21), The first recessed groove (2131) and the second recessed groove (2132) are provided to face each other. A third recessed groove (2133) is provided on the bottom wall of the first recessed groove (2131) and / or the bottom wall of the second recessed groove (2132). When internal pressure of the battery case (21) reaches a threshold, the pressure release region (213) is configured to burst in the third recessed groove (2133) to release the internal pressure. The pressure release region provided in the battery case (21) is easy to process.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] This application relates to the field of energy storage devices, and more specifically to battery cases, battery cells, batteries, and manufacturing methods and apparatuses for battery cases.

Background Art

[0002] Lithium-ion batteries have advantages such as small volume, high energy density, long cycle life, and long storage period, and are widely used in fields such as some electronic devices, electric transportation, and electric toys. For example, they are widely used in mobile phones, notebook computers, electric bicycles, electric vehicles, electric airplanes, electric boats, electric toy cars, electric toy boats, electric toy airplanes, and electric tools.

[0003] With the continuous development of lithium-ion battery technology, the requirements for the safety of lithium-ion batteries are increasing. The pressure relief mechanism of lithium-ion batteries has an important impact on the safety of lithium-ion batteries. For example, when phenomena such as short circuit and overcharging occur in a lithium-ion battery, thermal runaway may occur inside the lithium-ion battery, and the internal air pressure may rise rapidly. At this time, the pressure relief mechanism needs to operate to release the internal air pressure to the outside, thereby preventing the explosion of the lithium-ion battery. Therefore, the design of the pressure relief mechanism is extremely important.

Summary of the Invention

Problems to be Solved by the Invention

[0004] This application proposes a battery case, a battery cell, a battery, and manufacturing methods and apparatuses for a battery case to improve the performance of the battery.

Means for Solving the Problems

[0005] According to the first aspect of the present application, a battery case is provided, which includes a pressure release area. The pressure release area includes a first concave groove provided on the inner surface of the battery case and a second concave groove provided on the outer surface of the battery case. The first concave groove and the second concave groove are provided opposite to each other, and a third concave groove is provided on the bottom wall of the first concave groove and / or the bottom wall of the second concave groove. The pressure release area is configured to rupture at the third concave groove to release the internal pressure when the internal pressure of the battery case reaches a threshold value.

[0006] In the battery case of the embodiment of the present application, a pressure release area is provided. The pressure release area includes a first concave groove and a second concave groove provided on the inner and outer surfaces of the battery case respectively. Further, a third concave groove may be provided on the bottom wall of the third and / or second concave groove of the first concave groove. Thereby, the thickness at the third concave groove of the pressure release area is smaller than the thickness of other areas of the battery case. In this way, when thermal runaway occurs inside the battery cell, the battery case can rupture at the relatively fragile third concave groove to release the internal pressure. Moreover, compared with the method of separately attaching a pressure release mechanism to the battery case, the pressure release area in the embodiment of the present application has a simpler processing process. For example, the first concave groove, the second concave groove, and the third concave groove may be provided by a punching method. The first concave groove and the second concave groove are provided opposite to each other. Specifically, the two concave grooves may be processed simultaneously by a symmetric punching method. The processing process is simple and rapid. Also, the dimensions and shapes of the three concave grooves can be set flexibly and adjusted according to actual applications.

[0007] In some embodiments, the third concave groove is provided on the bottom wall of the second concave groove.

[0008] Considering that the first concave groove is provided on the inner surface of the battery case, if the third concave groove is provided on the bottom wall of the first concave groove, since there is electrolyte in the battery case, the electrolyte will accumulate in the third concave groove and corrode the third concave groove part. As a result, the pressure release area may rupture prematurely at the third concave groove. Therefore, usually, the third concave groove is provided on the bottom wall of the second concave groove located on the outer surface, thereby avoiding corrosion by the electrolyte.

[0009] In some embodiments, the thickness of the pressure release region in the third concave groove is 0.16 mm to 0.25 mm.

[0010] In some embodiments, the axis perpendicular to the bottom wall of the first concave groove and the axis perpendicular to the bottom wall of the second concave groove are the same.

[0011] That is, the first concave groove and the second concave groove are provided opposite to each other. In this way, the structure of the pressure release region is relatively symmetric, which is beneficial to realizing more accurate directional rupture of the pressure release region.

[0012] In some embodiments, there are protrusions on the outer surface of the battery case and surrounding the second concave groove.

[0013] Considering that when the first concave groove and the second concave groove are processed by punching, protrusions usually exist on the edges of the concave grooves. If the protrusions are provided inside, it will affect the installation of the internal electrode assembly. Therefore, the protrusions may be provided on the outer surface of the housing.

[0014] In some embodiments, the height by which the protrusion protrudes from the outer surface of the battery case is 0.25 mm to 1 mm.

[0015] In some embodiments, the shape of the bottom wall of the first concave groove and / or the shape of the bottom wall of the second concave groove is elongated.

[0016] The elongated concave groove is easier to process.

[0017] In some embodiments, the width of the bottom wall of the first concave groove and / or the width of the bottom wall of the second concave groove is 3 mm to 6 mm.

[0018] In some embodiments, the area of the bottom wall of the first concave groove is 150 mm 2 ~330 mm 2 and / or the area of the bottom wall of the second concave groove is 150 mm 2 ~330 mm 2 and the area of the bottom wall of the second concave groove is 150 mm

[0019] In some embodiments, the depth of the first concave groove with respect to the inner surface of the battery case is 0.4 mm to 0.7 mm, and / or the depth of the second concave groove with respect to the outer surface of the battery case is 0.3 mm to 0.6 mm.

[0020] In some embodiments, the shape of the bottom wall of the third concave groove is elongated.

[0021] In some embodiments, the length of the third concave groove is 40 mm to 100 mm.

[0022] In some embodiments, the first concave groove and / or the second concave groove is an annular concave groove.

[0023] In some embodiments, the area of the bottom wall of the first concave groove is 400 mm 2 ~1000 mm 2 and / or the area of the bottom wall of the second concave groove is 600 mm 2 ~1200 mm 2 is.

[0024] In some embodiments, the depth of the first concave groove with respect to the inner surface of the battery case is 1 mm to 2 mm, and / or the depth of the second concave groove with respect to the outer surface of the battery case is 0.3 mm to 0.6 mm.

[0025] In some embodiments, an annular fourth concave groove is provided on the bottom wall of the second concave groove, and the third concave groove is provided on the bottom wall of the fourth concave groove.

[0026] When a thermal runaway occurs inside the battery cell, the pressure release area is more likely to rupture. Therefore, the thickness in the third concave groove should be set smaller so that the third concave groove in the pressure release area can rupture, realizing more accurate directional rupture and exhaust. A fourth concave groove is provided in the second concave groove, and further a third concave groove is provided on the bottom wall of the fourth concave groove. In this way, a thinner third concave groove region can be obtained more easily.

[0027] In some embodiments, the area of the bottom wall of the fourth concave groove is 200 mm2 ~800 mm 2 is.

[0028] In some embodiments, the battery case is used to protect the pressure release region, and further includes a protective sheet provided on the outer surface of the battery case and covering the second concave groove.

[0029] In some embodiments, the thickness of the protective sheet is 0.1 mm to 0.2 mm.

[0030] The protective sheet provided on the side away from the inside of the battery case in the pressure release region can protect the pressure release region from the influence of external members.

[0031] The pressure release region in the embodiments of the present application is formed by a concave groove. Therefore, when the protective sheet is provided on the outer surface of the battery case and covers the second concave groove, there is a gap between the protective sheet and the pressure release region. In this way, when the pressure release region exhausts, the gap between the protective sheet and the pressure release region can ensure that the pressure release region has a certain open space, and when the protective sheet adheres to the pressure release region, it can also prevent the wear of the pressure release region and further protect the pressure release region.

[0032] In some embodiments, the battery case includes a housing that is a hollow rectangular parallelepiped and has an opening at one end, and a cover plate that covers the opening of the housing.

[0033] In some embodiments, the pressure release region is located on the bottom wall of the housing, and the bottom wall of the housing is the wall facing the opening of the housing.

[0034] When considering that the electrode terminals are usually provided on the cover plate of the battery case, if the pressure release area is also provided on the cover plate, when thermal runaway occurs inside the battery cell, the pressure release area will rupture, releasing the internal air pressure of the battery cell, and at the same time, ejecting liquid or solid combustion products outwards, and there may be conductive substances contained therein. As a result, a short circuit between the electrode terminals will be caused. Also, when the battery is installed in a vehicle, usually the electrode terminals face upwards, that is, considering the direction towards the passengers, if the pressure release area is attached to the same side as the electrode terminals, substances such as airflows released when the pressure release area ruptures will be discharged upwards, thus potentially causing burns and heat injuries to the passengers and increasing the danger to the passengers. Therefore, when the pressure release area is provided on the bottom wall of the housing, the pressure release area discharges downwards, and the above problems can be avoided.

[0035] In some embodiments, the thickness of the bottom wall of the housing is 1.2 mm to 2 mm.

[0036] In some embodiments, the battery case further includes electrode terminals, and all of the electrode terminals include a positive electrode terminal and a negative electrode terminal provided on the cover plate.

[0037] According to the second aspect of the present application, a battery cell is provided, including the battery case described in the first aspect and any one possible implementation form of the first aspect, and an electrode assembly provided in the battery case.

[0038] In some embodiments, the battery case includes a housing that is a hollow rectangular parallelepiped and has an opening at one end, and a cover plate that closes the opening of the housing.

[0039] In some embodiments, the battery cell further includes a backing plate located between the electrode assembly and the bottom wall of the housing, and the bottom wall of the housing is the wall of the housing that faces the opening of the housing.

[0040] The backing plate further protects the pressure release area and can avoid the impact of the electrode assembly and the electrolyte inside the battery case on the pressure release area.

[0041] In some embodiments, the pressure release area is located on the bottom wall of the housing, and the backing plate is provided with a through hole corresponding to the pressure release area, so that the backing plate does not shield the pressure release area.

[0042] When the pressure release area is located on the bottom wall, if it can be ensured that the strength of the pressure release area is not destroyed by the electrode assembly and the electrolyte, when a thermal runaway occurs inside the battery cell, considering that the backing plate may prevent the gas from rupturing the pressure release area, therefore, in order to make the pressure release area rupture more easily, a partial area of the backing plate may be removed to form an avoidance area. For example, at the position of the pressure release area, one through hole may be correspondingly provided on the backing plate, so that the backing plate does not shield the pressure release area.

[0043] According to the third aspect of the present application, a battery is provided, including a plurality of battery cells including at least one battery cell described in any one of the above second aspect and possible implementation forms of the second aspect, a bus bar member used to realize the electrical connection of the plurality of battery cells, and a housing used to accommodate the plurality of battery cells and the bus bar member.

[0044] According to the fourth aspect of the present application, a power consumption device including the battery described in the third aspect is provided.

[0045] The power consumption device can be a vehicle, a ship or a spacecraft.

[0046] According to the fifth aspect of the present application, there is provided a method for manufacturing a battery case, including the steps of forming a pressure release area of the battery case by providing a first concave groove on the inner surface of the battery case and a second concave groove on the outer surface of the battery case, wherein the first concave groove and the second concave groove are provided opposite to each other; and providing a third concave groove on the bottom wall of the first concave groove and / or the bottom wall of the second concave groove, wherein the pressure release area is configured to rupture at the third concave groove to release the internal pressure when the internal pressure of the battery case reaches a threshold value.

[0047] In some embodiments, there are protrusions on the outer surface of the battery case and surrounding the second concave groove.

[0048] In some embodiments, the shape of the bottom wall of the first concave groove and / or the shape of the bottom wall of the third concave groove is elongated.

[0049] In some embodiments, the first concave groove and / or the second concave groove is an annular concave groove.

[0050] As can be understood, the method for manufacturing a battery case in the embodiments of the present application can be used to manufacture the battery case in any one of the possible implementation forms of the first aspect and the first aspect above.

[0051] According to the sixth aspect of the present application, there is provided an apparatus for manufacturing a battery case, including an installation module, which is used to form a pressure release area of the battery case by installing a first concave groove on the inner surface of the battery case and a second concave groove on the outer surface of the battery case, wherein the first concave groove and the second concave groove are provided opposite to each other, and is used to install a third concave groove on the bottom wall of the first concave groove and / or the bottom wall of the second concave groove, and the pressure release area is configured to rupture at the third concave groove to release the internal pressure when the internal pressure of the battery case reaches a threshold value.

[0052] In some embodiments, there are protrusions on the outer surface of the battery case and surrounding the second concave groove.

[0053] In some embodiments, the shape of the bottom wall of the first concave groove and / or the shape of the bottom wall of the third concave groove are elongated.

[0054] In some embodiments, the first concave groove and / or the second concave groove are annular concave grooves.

[0055] As can be understood, the manufacturing apparatus of the battery case in the embodiments of the present application can be used to execute the method in any possible implementation form of the above fifth aspect or the fifth aspect. Specifically, the apparatus includes a unit for executing the method in any possible implementation form of the above fifth aspect or the fifth aspect.

[0056] The drawings described herein are for further understanding of the present application, form a part of the present application, and the exemplary embodiments and their descriptions of the present application are used to interpret the present application and do not unduly limit the present application.

Brief Description of the Drawings

[0057]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Embodiments for Carrying Out the Invention

[0058] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, hereinafter, with reference to the drawings of the embodiments of the present application, the technical solutions of the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are some of the embodiments of the present application, not all of them. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the present application.

[0059] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by those skilled in the art. In this specification, the terms used in the description of the application are only for the purpose of explaining specific embodiments, but do not limit the present application. The terms "comprising", "having" and any variations thereof in the description, claims and brief description of the above drawings of the present application are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the description and claims of the present application or the above drawings are used to distinguish different objects, but not for explaining a specific order or primary-secondary relationship.

[0060] References to "Examples" in this specification mean that the specific features, structures, or characteristics described with reference to the Examples may be included in at least one embodiment of the present application. Although this phrase appears in various positions in the specification, it does not necessarily refer to the same embodiment, nor are they independent or alternative embodiments that exclude each other. As can be explicitly and implicitly understood by those skilled in the art, the embodiments described in this specification may be combined with other embodiments.

[0061] In this specification, the term "and / or" simply describes the relationship of the relevant objects and indicates that three types of relationships may exist. For example, A and / or B may indicate three types: when only A exists, when both A and B exist, and when only B exists. Also, in this specification, the character " / " generally indicates that the relevant objects before and after it are in an "or" relationship.

[0062] "Plurality" as it appears in this application means two or more (including two), similarly, "a plurality of sets" means two sets or more (including two), and "a plurality of sheets" means two sheets or more (including two).

[0063] The battery cases, battery cells, and batteries provided with a plurality of battery cells described in the embodiments of the present application can all be applied to various devices using batteries, for example, mobile phones, portable devices, notebook computers, electric bicycles, electric vehicles, steamships, spacecraft, electric toys, and electric tools, etc. For example, spacecraft includes airplanes, rockets, space shuttles, and spaceships, etc., electric toys include fixed or mobile electric toys, for example, game consoles, electric vehicle toys, electric boat toys, and electric airplane toys, etc., and electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, for example, electric drills, electric grinders, electric wrenches, electric drivers, electric hammers, impact drills, concrete vibrators, and electric planers.

[0064] The battery case, battery cell, and battery provided with a plurality of battery cells described in the embodiments of the present application can be applied not only to the devices described above but also to all devices using batteries. However, for the sake of simplicity of explanation, all of the following embodiments will be described by taking an electric vehicle as an example.

[0065] For example, as shown in FIG. 1, it is a structural schematic diagram of a vehicle 1 in an embodiment of the present application. The vehicle 1 may be a fuel vehicle, a fuel gas vehicle, or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle, an extended-range electric vehicle, or the like. A battery 10 may be provided inside the vehicle 1. The battery 10 may be a battery pack or a battery module. For example, the battery 10 may be provided at the bottom, front, or rear of the vehicle 1. A controller 30 and a motor 40 may further be provided inside the vehicle 1. The battery 10 may be used for power supply of the vehicle 1. For example, the battery 10 may be used as an operating power source of the vehicle 1 and used in the circuit system of the vehicle 1. For example, it is used for the starting, navigation, and operating power requirements during driving of the vehicle 1. In another embodiment of the present application, the battery 10 can be used not only as an operating power source of the vehicle 1 but also as a driving power source of the vehicle 1, and provides driving power to the vehicle 1 by replacing or partially replacing fuel or natural gas.

[0066] To meet various power usage demands, the battery 10 may include one or more battery modules (which may also be referred to as battery units). The multiple battery modules may be connected in series, in parallel, or in a series-parallel connection, where the series-parallel connection is a combination of series and parallel connections. For example, as shown in FIG. 2, which is a structural schematic diagram of the battery 10 in another embodiment of the present application, the battery 10 includes a first cover 111, a second cover 112, and multiple battery modules 11. The shapes of the first cover 111 and the second cover 112 may be determined according to the shape formed by combining the one or more battery modules 11. Both the first cover 111 and the second cover 112 have one opening. For example, both the first cover 111 and the second cover 112 are hollow rectangular parallelepipeds and only one surface of each is the opening surface, that is, this surface has no housing wall and communicates the inside and outside of the housing. The first cover 111 and the second cover 112 are engaged with each other at the opening location to form a sealed casing of the battery 10. After the one or more battery modules 11 are combined by being connected in parallel, in series, or in a series-parallel connection with each other, they are arranged in the casing formed by engaging the first cover 111 and the second cover 112.

[0067] In another embodiment of the present application, when the battery 10 includes one battery module 11, the battery module 11 is arranged in the casing formed by engaging the first cover 111 and the second cover 112.

[0068] The power generated by the one or more battery modules 11 is led out by a conductive mechanism (not shown) passing through the casing.

[0069] In addition to this, the battery 10 may further include other structures, which will not be described in detail here. For example, the battery 10 may further include a bus bar member used to realize the electrical connection between multiple battery cells (not shown). Further, for example, the battery 10 may further include a cooling member used to accommodate a cooling medium and cool down the one or more battery modules 11, but the embodiments of the present application are not limited thereto.

[0070] According to various power demands, the battery module 11 may include one or more battery cells. For example, as shown in FIG. 3, one battery module 11 may include a plurality of battery cells 20, and the plurality of battery cells 20 may be connected in series, in parallel, or in series-parallel to achieve a large capacity or power. Moreover, the number of the battery cells 20 provided in one battery module 11 may be set to any value. Each battery cell 20 may include, but is not limited to, a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, or a magnesium-ion battery. The battery cell 20 may have a cylindrical shape, a flat shape, a cuboid shape, or other shapes.

[0071] In another embodiment of the present application, the plurality of battery cells 20 may be integrally stacked, and the plurality of battery cells 20 may be connected to each other in series, in parallel, or in series-parallel. In another embodiment of the present application, each battery cell 20 may have a rectangular shape, a cylindrical shape, or other shapes.

[0072] Each battery cell 20 may include a battery case and an electrode assembly provided in the battery case. The battery case may include two parts, a housing and a cover plate. The housing may be a hollow cuboid, cube, or cylinder, and one surface of the housing may have an opening so that the electrode assembly can be easily arranged in the housing. The cover plate is connected to the housing at the opening of the housing to form a sealed battery case of the battery cell 20, and the housing may be filled with an electrolyte.

[0073] In addition, the battery case further includes two electrode terminals, which are usually provided on the cover plate and connected to the electrode assembly. A pressure release mechanism may be further provided on the flat surface of the cover plate. The pressure release mechanism may be a part of the flat surface of the cover plate or may be welded to the flat surface of the cover plate. In the normal state, the pressure release mechanism is hermetically coupled to the cover plate. That is, the cover plate is connected to the housing at the opening of the housing to form the battery case of the battery cell 20, and the space formed by the battery case is hermetically sealed. When there is too much gas generated in the battery cell 20, if the gas expands and the air pressure in the battery case rises and exceeds a predetermined value, the pressure release mechanism ruptures and can communicate the inside and outside of the battery case, and the gas is released to the outside from the rupture location of the pressure release mechanism, further avoiding the occurrence of an explosion.

[0074] In a conventional battery cell, the pressure release mechanism is usually provided on the cover plate and located on the same side as the electrode terminals. When a thermal runaway occurs inside the battery cell, the pressure release mechanism ruptures, releasing the internal air pressure of the battery cell and at the same time ejecting liquid or solid combustion products to the outside, and there may be conductive substances contained therein. As a result, a short circuit between the electrode terminals is caused. Also, when the battery is installed in a vehicle, usually the electrode terminals face upward, that is, considering the direction of the passengers, if the pressure release area is installed on the same side as the electrode terminals, substances such as the airflow released when the pressure release area ruptures are discharged upward, and thus there is a possibility of causing burns or heat injuries to the passengers, increasing the danger to the passengers. Therefore, it may be considered to install the pressure release mechanism at another position to solve the above problems. For example, it may be installed in the housing under the cover plate, for example, on the bottom wall of the housing.

[0075] However, when the pressure release mechanism is attached to the housing, although the housing has a hollow structure with one end open, since the pressure release mechanism is usually sheet-shaped, there may be a problem that it is inconvenient to attach the pressure release mechanism to the housing. Especially when it is attached to the bottom wall of the housing, due to the limitation of the depth of the housing, it is difficult to directly weld the sheet-shaped pressure release mechanism to the bottom wall. Therefore, the embodiments of the present application provide a battery case with a pressure release area, which can solve the above problems.

[0076] Specifically, continuing with the embodiment shown in FIGS. 1-3 as an example, FIG. 4 shows another embodiment of the battery cell 20 in the embodiment of the present application. As shown in FIG. 4, the battery cell 20 includes a battery case (not shown), one or more electrode assemblies 22, and a connection member 23. The battery case in the embodiment of the present application includes a housing 211 and a cover plate 212.

[0077] Specifically, as shown in FIG. 4, the housing 211 provided in the battery case of the battery cell 20 may be determined according to the shape of one or more combined electrode assemblies 22. For example, the housing 211 may be a hollow rectangular parallelepiped or cube or cylindrical shape, and one surface of the housing 211 has one opening so that one or more electrode assemblies 22 can be arranged in the housing 211. For example, when the housing 211 is a hollow rectangular parallelepiped or cube, one plane of the housing 211 is the opening surface, that is, this plane has no housing wall and communicates the inside and outside of the housing 211. When the housing 211 may be a hollow cylindrical shape, the circular side surface of the housing 211 is the opening surface, that is, this circular side surface has no housing wall and communicates the inside and outside of the housing 211. The cover plate 212 is connected to the housing 211 at the opening of the housing 211 to form a sealed battery case, and the housing 211 is filled with electrolyte.

[0078] As shown in FIG. 4, the battery case of the battery cell 20 may further include two electrode terminals 214, and the two electrode terminals 214 may be provided on the cover plate 212. The cover plate 212 is usually in a flat plate shape, and the two electrode terminals 214 are located on the flat plate surface of the cover plate 212 and penetrate the flat plate surface of the cover plate 212. The two electrode terminals 214 are a positive electrode terminal 214a and a negative electrode terminal 214b respectively. One connection member 23 is provided corresponding to each electrode terminal 214. The connection member 23 may also be referred to as a current collecting member 23 or a copper-aluminum adapter sheet 23, and is located between the cover plate 212 and the electrode assembly 22.

[0079] As shown in FIG. 4, specifically, each electrode assembly 22 may include at least one positive electrode tab 221 and at least one negative electrode tab 222. Further, the electrode assembly 22 may further include a bare cell and an insulating sheet that wraps the bare cell. In FIG. 4, the specific positions of the positive electrode tab 221 and the negative electrode tab 222 are not distinguished. The positive electrode tab 221 of the one or more electrode assemblies 22 is connected to one electrode terminal via one connection member 23, and the negative electrode tab 222 of the one or more electrode assemblies 22 is connected to another electrode terminal via another connection member 23. For example, the positive electrode terminal 214a is connected to the positive electrode tab 221 via one connection member 23, and the negative electrode terminal 214b is connected to the negative electrode tab 222 via another connection member 23.

[0080] In the battery cell 20, one or more electrode assemblies 22 may be provided according to actual usage requirements. As shown in FIG. 4, at least two independent electrode assemblies 22 are provided in the battery cell 20.

[0081] In the battery cell 20, the electrode assembly 22 may have a wound structure or a stacked structure, but the embodiments of the present application are not limited thereto.

[0082] In addition, as shown in FIG. 4, the battery cell 20 may further include a backing plate 24, which is located between the electrode assembly 22 and the bottom wall of the housing 211, and can not only exert a supporting effect on the electrode assembly 22, but also effectively prevent interference between the electrode assembly 22 and the fillet around the bottom wall of the housing 211. The shape of the backing plate 24 in the embodiment of the present application may be set according to actual applications. For example, the backing plate 24 may be set to a rectangle that matches the shape of the bottom wall of the housing 211, or, as shown in FIG. 4, may be set to other shapes. In addition, one or more through holes may be provided in the backing plate 24. For example, a plurality of through holes arranged uniformly or symmetrically may be provided. In this way, the spaces on the upper and lower surfaces of the backing plate 24 can be communicated, and both the electrolyte and the gas and electrolyte generated inside the electrode assembly 22 can freely pass through the backing plate 24, facilitating the guiding of the electrolyte and gas.

[0083] The thickness of the backing plate 24 is generally set to 0.3-5 mm, and preferably it is an insulating member, but it may also be a non-insulating member. For example, the material of the backing plate 24 may be a material having both electrolyte resistance and insulation properties, such as PP, PE, PET, PPS, Teflon (registered trademark), stainless steel, aluminum, etc. For plastic materials such as PP, PE, PET, and PPS, a refractory material may be selected, or insulation may be performed on the surface of a metal material such as aluminum or stainless steel by anodization.

[0084] In addition, the battery cell 20 in the embodiment of the present application may further include other members. For example, the battery cell 20 may further include at least one of a top cover patch, a sealing nail, and a plastic nail, and the top cover patch, the sealing nail, and the plastic nail may be attached to the cover plate 212. In addition, the battery cell 20 may further include a blue film provided on the outer surface of the battery housing 211, which plays a role in insulating and protecting the battery cell. However, the embodiment of the present application is not limited thereto.

[0085] In the embodiment of the present application, a pressure release region may be further provided on the housing 211 or the cover plate 212 of the battery case. For example, the pressure release region may be provided on the bottom wall of the housing 211 in FIG. 4. Specifically, taking FIG. 5 as an example, FIG. 5 shows a schematic diagram of the battery case 21. In the embodiment of the present application, the battery case 21 in FIG. 5 includes the housing 211 and the cover plate 212 shown in FIG. 4. As shown in FIG. 5, when the battery case 21 having a rectangular parallelepiped (i.e., hexahedron) shape is taken as an example for description here, the battery case 21 includes six walls (or also referred to as six faces). FIG. 5 shows any three adjacent walls of the battery case 21. However, the pressure release region 213 in the embodiment of the present application may be provided on any one of the walls of the battery case 21. For example, the pressure release region 213 may be provided on the bottom wall of the housing 211 of the battery case 21. The bottom wall of the housing 211 and the opening of the housing 211 are opposed to each other. That is, in FIG. 5, the wall provided with the pressure release region 213 of the battery case 21 shows the bottom wall of the housing 211. Further, for example, as shown in FIG. 6, the pressure release region 213 may be provided on any one of the side walls of the housing 211. However, the embodiment of the present application is not limited thereto. The pressure release region 213 in the embodiment of the present application is used to operate and release the internal pressure when the internal pressure of the battery case 21 reaches a threshold value.

[0086] In the embodiments of the present application, the battery case 21 is a cuboid. In this case, the housing 211 has four side walls, namely two side walls with a large area and two side walls with a small area. When the pressure release region 213 is provided on the side wall of the housing 211, for example, as shown in FIG. 6, the pressure release region 213 is usually provided on the side wall with a small area. When assembling a plurality of battery cells to form a battery, for example, in the mounting method shown in FIG. 3, for a cuboid-shaped battery cell, considering the arrangement between two adjacent battery cells, usually the walls with a large area among the housing side walls of the two battery cells are in contact with each other. Therefore, if the pressure release region 213 is provided on the side wall with a large area, when assembling a plurality of battery cells closely side by side to form a battery, it will affect the opening of the pressure release region 213. For example, it is necessary to leave a space for the pressure release region 213 to open between the battery cells. This is disadvantageous for the mounting of a plurality of battery cells. Therefore, by attaching the pressure release region 213 to the side wall with a small area, it is advantageous for the arrangement between a plurality of battery cells, and furthermore, the energy density of the battery can be improved.

[0087] When the pressure release region 213 is provided on the bottom wall of the housing 211, considering the pressure of the internal electrode assembly 22 on the pressure release region 213, for example, in the case of a battery mounted in a vehicle, since the vehicle shakes during driving, the electrode assembly 22 and the electrolyte exert an impact on the side wall and the bottom wall of the housing 211. The pressure release region 213 is thinner than other regions of the bottom wall of the housing. Therefore, as shown in FIG. 4, the backing plate 24 provided between the electrode assembly 22 and the bottom wall of the housing 211 can exert a buffering effect on the pressure release region 213 below it, preventing the electrolyte and the electrode assembly 22 from impacting the pressure release region 213 and causing the rupture of the pressure release region 213 during vibration and impact.

[0088] However, on the other hand, the backing plate 24 on the bottom wall covers the pressure release area 213 to protect the pressure release area 213. At the same time, the backing plate 24 may also prevent the gas from rupturing the pressure release area 213. Therefore, an avoidance area may be provided on the backing plate 24 to ensure that the backing plate does not shield the pressure release area 213. That is, depending on elements such as the thickness and strength of the pressure release area 213 in actual applications, it may be selected whether to provide an avoidance area on the backing plate 24 or not.

[0089] Specifically, when an avoidance area is provided on the backing plate 24 to ensure that the backing plate does not shield the pressure release area 213, as shown in FIG. 7, here, the rectangular parallelepiped-shaped backing plate 24 is taken as an example for description. A partial area of the backing plate 24 is removed. That is, at the position of the pressure release area 213, one through hole may be correspondingly provided on the backing plate 24 as the avoidance area 241, so that the backing plate 24 does not shield the pressure release area. The shape of the avoidance area 241 of the backing plate 24 usually conforms to the shape of the surface on the side close to the inside of the housing 211 of the pressure release area 213. FIG. 7 is merely an example, and the embodiments of the present application are not limited thereto.

[0090] And, since the backing plate 24 does not completely shield the pressure release area 213, usually, the area of the avoidance area 241 of the backing plate 24 may be set to be larger than the area of the pressure release area 213. Or, considering that the pressure release area 213 in the embodiments of the present application is provided in the through hole of the bottom wall of the housing 211, therefore, the area of the avoidance area 241 of the backing plate 24 is larger than the area of the through hole of the bottom wall of the housing 211, but the embodiments of the present application are not limited thereto.

[0091] Hereinafter, the pressure release region 213 in the embodiments of the present application will be described in detail with reference to the drawings. Specifically, here, it is taken as an example that the pressure release region 213 is provided on the bottom wall of the housing 211. FIG. 8 shows a cross-sectional view of the housing 211 in the embodiment of the present application. For example, the surface shown in the cross-sectional view is a plane that passes through the pressure release region 213 and is parallel to the side wall with a small area of the housing 211. FIG. 9 is an enlarged view of the region A1 in FIG. 8, and the pressure release region 213 is included in the region A1. The upper side in FIG. 9 corresponds to the inside of the housing 211, and the lower side in FIG. 9 corresponds to the outside of the housing 211. Specifically, as shown in FIG. 9, the pressure release region 213 in the embodiment of the present application may include a first concave groove 2131 provided on the inner surface of the housing 211 of the battery case 21 and a second concave groove 2132 provided on the outer surface of the housing 211 of the battery case 21. The first concave groove 2131 and the second concave groove 2132 are provided opposite to each other. A third concave groove 2133 is provided on the bottom wall of the first concave groove 2131 and / or the bottom wall of the second concave groove 2132. The pressure release region 213 is configured to rupture at the third concave groove 2133 to release the internal pressure when the internal pressure of the battery case 21 reaches a threshold value.

[0092] Thus, when a thermal runaway occurs inside the battery cell, the battery case 21 can rupture at the relatively fragile third concave groove 2133 to release the internal pressure. Moreover, compared with the method of separately attaching a pressure release mechanism to the battery case 21, the pressure release region 213 in the embodiment of the present application has a simpler processing process. For example, the first concave groove 2131, the second concave groove 2132, and the third concave groove 2133 may be provided by a punching method. The first concave groove 2131 and the second concave groove 2132 are provided oppositely. Specifically, the two concave grooves may be processed simultaneously by a symmetric punching method. The processing process is simple and rapid. Also, the dimensions and shapes of the three concave grooves can be flexibly set and adjusted according to actual applications. Moreover, the material used for the housing 211 is usually metal aluminum. In this case, the material of the pressure release region 213 is also aluminum. Compared with the pressure release mechanism of other separately provided materials, the pressure release region 213 in the embodiment of the present application is easier to process, is more likely to be opened in a timely manner when a thermal runaway occurs inside the battery case 21, makes the exhaust smoother, and has a high exhaust speed.

[0093] Also, considering that the electrode terminal 214 is usually provided on the cover plate 212 of the battery case 21, if the pressure release region 213 is also provided on the cover plate 212, when a thermal runaway occurs inside the battery cell 20, the pressure release region 213 ruptures, releasing the internal air pressure of the battery cell 20 and at the same time spraying liquid or solid combustion products outward, and there may be conductive substances contained therein. As a result, a short circuit between the electrode terminals 214 is caused. Also, when the battery is installed in a vehicle, usually, the electrode terminal 214 faces upward, that is, considering the direction of the passenger, if the pressure release region 213 is attached to the same side as the electrode terminal 214, substances such as the airflow released when the pressure release region 213 ruptures are discharged upward. In this way, there is a possibility of causing burns or scalds to the passenger, increasing the danger to the passenger. Therefore, in the embodiment of the present application, it can be flexibly selected whether the pressure release region 213 is provided on the bottom wall or the side wall of the housing 211 of the battery case 21, without being restricted by the processing method.

[0094] In the embodiment of the present application, the third concave groove 2133 may be provided on the bottom wall of the first concave groove 2131 and / or the bottom wall of the second concave groove 2132. However, considering that the first concave groove 2131 is provided on the inner surface of the battery case 21, if the third concave groove 2133 is provided on the bottom wall of the first concave groove 2131, since there is electrolyte in the battery case 21, the electrolyte will accumulate in the third concave groove 2133 and corrode the third concave groove 2133 portion. As a result, the pressure release area 213 may rupture by being lifted at the third concave groove 2133. Therefore, usually, the third concave groove 2133 is provided on the bottom wall of the second concave groove 2132 located on the outer surface, thereby avoiding the corrosion of the electrolyte. Hereinafter, the case where the third concave groove 2133 is provided on the bottom wall of the second concave groove 2132 will be taken as an example for explanation.

[0095] As can be understood, the positions of the first concave groove 2131 and the second concave groove 2132 in the embodiment of the present application are provided opposite to each other, or in the direction perpendicular to the pressure release area, the positions of the first concave groove 2131 and the second concave groove 2132 are opposite to each other. For example, with respect to the inner surface where the first concave groove 2131 of the battery case 21 is located, the projection of the second concave groove 2132 on the inner surface and the projection of the bottom wall of the first concave groove 2131 on the inner surface at least partially overlap. For example, hereinafter, the case where the first concave groove 2131 and the second concave groove 2132 are provided facing each other will be taken as an example for explanation, that is, the axis perpendicular to the bottom wall of the first concave groove 2131 and the axis perpendicular to the bottom wall of the second concave groove 2132 are the same.

[0096] The shapes of the bottom walls of the first concave groove 2131 and the second concave groove 2132 provided in the pressure release area 213 in the embodiment of the present application may be set according to actual applications, and the shapes of the bottom walls of the first concave groove 2131 and the second concave groove 2132 may be the same or different. For the convenience of explanation, hereinafter, the case where the shapes of the bottom walls of the first concave groove 2131 and the second concave groove 2132 are the same will be taken as an example for explanation. The shapes of the bottom walls of the first concave groove 2131 and the second concave groove 2132 may be rectangular, circular, elliptical or annular. Hereinafter, two embodiments will be referred to for detailed explanation.

[0097] Optionally, as a first embodiment, as shown in FIGS. 8 and 9, the shape of the bottom wall of the first concave groove 2131 and the shape of the bottom wall of the second concave groove 2132 may be annular, for example, square annular, circular annular or annular in other shapes. For example, here, the racetrack-shaped annulus shown in FIG. 5 is taken as an example. The racetrack shape is similar to an ellipse, with both ends being arc-shaped and the middle being linear. However, the embodiments of the present application are not limited thereto.

[0098] As shown in FIG. 9, for the convenience of processing, providing a third concave groove 2133 on the bottom wall of the second concave groove 2132 may include providing a fourth concave groove 2134 on the bottom wall of the second concave groove 2132 and providing the third concave groove 2133 on the bottom wall of the fourth concave groove 2134. Considering that the shape of the bottom wall of the second concave groove 2132 is annular, therefore, the shape of the bottom wall of the fourth concave groove 2134 may be consistent with the shape of the bottom wall of the second concave groove 2132 and may be set to be annular. However, the embodiments of the present application are not limited thereto.

[0099] As shown in FIG. 9, the cross-sectional shapes of the first concave groove 2131, the second concave groove 2132, the third concave groove 2133 and the fourth concave groove 2134 in the embodiments of the present application may be set according to actual applications. For example, regarding the angle formed by the bottom wall and the side wall of the concave groove, it may be a right-angled concave groove shown in the second concave groove 2132 and the fourth concave groove 2134 in FIG. 9, or an inclined concave groove shown in the first concave groove 2131 and the third concave groove 2133 in FIG. 9. However, the embodiments of the present application are not limited thereto.

[0100] As shown in FIG. 9, the first concave groove 2131 and the second concave groove 2132 are annular concave grooves. Therefore, there is a protruding structure in their central region. Here, the protruding structure 2136 close to the inside of the housing 211 will be taken as an example for explanation. The protruding structure 2136 is in the middle region of the annular first concave groove 2131. The surface of the protruding structure 2136 close to the housing 211 does not protrude with respect to the inner surface of the housing 211 excluding the pressure release region 213. For example, the surface of the protruding structure 2136 close to the housing 211 may be substantially flush with the inner surface of the housing 211 excluding the pressure release region 213, or, as shown in FIG. 9, the surface of the protruding structure 2136 close to the housing 211 may be recessed with respect to the inner surface of the housing 211 excluding the pressure release region 213, but the embodiments of the present application are not limited thereto.

[0101] Also, the periphery of the first concave groove 2131 does not protrude with respect to the inner surface of the housing 211. In this way, there is no protruding portion on the inner surface of the housing 211. When installing members such as the electrode assembly inside the housing 211, it is not affected and there is no need to perform additional design to avoid the protruding portion, thereby saving the internal space.

[0102] As shown in FIG. 9, regarding the outside of the housing 211, there may be further protrusions 2137 on the outer surface of the housing 211, surrounding the second concave groove 2132. The protrusions 2137 extend in a direction away from the inside of the housing 211 with respect to the outer surface of the housing 211. Considering that there are usually protrusions at the edges of the concave grooves when processing the first concave groove 2131 and the second concave groove 2132 by punching, if the protrusions are provided inside, it will affect the installation of the internal electrode assembly. Therefore, the protrusions 2137 may be provided on the outer surface of the housing 211.

[0103] When assembling the battery cell 20 to form the battery 10, assuming that it is necessary to provide a member below the battery cell 20, for example, a cooling plate used to cool the battery cell 20 may be provided, or a bottom protection plate may be provided, but the embodiments of the present application are not limited thereto. Due to the presence of the protrusion 2137, the member located below the battery cell 20 may be assembled with the battery cell 20 by providing an avoidance area recessed on the surface. For example, when a cooling plate is provided below the battery cell 20, by providing a concave groove or a through hole in the area corresponding to the pressure release area 213 of the cooling plate, the protruding protrusion 2137 of the pressure release area 213 can be accommodated in the concave groove or the through hole, thereby saving space.

[0104] Also, due to the presence of the protrusion 2137, there is a gap between the surface of the housing 211 of the pressure release area 213 away from the inside and the surface of the member (for example, a cooling member or a bottom protection plate) located below the pressure release area 213. In this case, the pressure release area 213 can have a certain open space during exhaust, ensuring that the third concave groove 2133 of the pressure release area 213 ruptures and opens to release the internal pressure.

[0105] As shown in FIG. 9, in order to protect the side of the pressure release area 213 away from the housing 211 from the influence of other members outside the battery case 21, the pressure release area 213 may further include a protective sheet 2135 provided on the outer surface of the battery case 21 and covering the second concave groove 2132 for protecting the pressure release area 213.

[0106] As can be understood, in the embodiments of the present application, the dimensions of each of the above parts may be set according to actual applications. For example, the following will be exemplarily described with reference to FIG. 9.

[0107] Regarding the dimensions of the pressure release area 213, the area of the bottom wall of the first concave groove is usually set to be 400mm 2 ~1000mm 2 and may be, for example, 400mm 2 , 700mm 2 or 1000mm2 It may be set to, and the area of the bottom wall of the second concave groove 2132 is usually 600 mm 2 ~1200 mm 2 It may be set to, for example, 600 mm 2 , 900 mm 2 or 1200 mm 2 It may be set to, and the area of the bottom wall of the fourth concave groove 2134 is usually 200 mm 2 ~800 mm 2 It may be set to, for example, 200 mm 2 , 500 mm 2 or 800 mm 2 It may be set to. In the embodiments of the present application, "mm 2 " represents square millimeters.

[0108] As shown in FIG. 9, here, taking the example that the pressure release region 213 is provided on the bottom wall of the housing 211, the thickness h1 of the bottom wall of the housing 211 may usually be set to 1.2 mm to 2 mm, for example, it may be set to 1.2 mm, 1.5 mm or 2 mm. The depth h2 of the first concave groove 2131 with respect to the inner surface of the battery case 21 may usually be set to 1 mm to 2 mm, for example, it may be set to 1 mm, 1.5 mm or 2 mm. The depth h3 of the second concave groove 2132 with respect to the outer surface of the battery case 21 is 0.3 mm to 0.6 mm, for example, it may be set to 0.3 mm, 0.4 mm or 0.6 mm. The thickness h4 between the bottom wall of the second concave groove 2132 and the bottom wall of the first concave groove 2131 may usually be set to 0.3 mm to 1 mm, for example, it may be set to 0.3 mm, 0.5 mm or 1 mm. The thickness h5 at the third concave groove 2133 of the pressure release region 213 may usually be set to 0.16 mm to 0.25 mm, for example, it may be set to 0.16 mm, 0.2 mm or 0.25 mm. In the embodiments of the present application, "mm" represents millimeters.

[0109] As shown in FIG. 9, referring to the relevant dimensions of the first concave groove 2131 and the second concave groove 2132, such as depth, the area of the bottom wall, etc., the height h6 by which the protrusion 2137 protrudes with respect to the outer surface of the battery case 21 may usually be set to 0.5 mm to 1 mm, for example, it may be set to 0.5 mm, 0.8 mm or 1 mm. Also, the thickness h7 of the protective sheet 2135 may usually be set to 0.1 mm to 0.2 mm, for example, it may be set to 0.1 mm, 0.15 mm or 0.2 mm.

[0110] Optionally, as a second embodiment, the shape of the bottom wall of the first concave groove 2131 and the shape of the bottom wall of the second concave groove 2132 may be set to other shapes, for example, they may be set to rectangular, circular or racetrack-shaped. Here, taking the example of being set to a long shape, the long shape is a special rectangle, that is, the length of the rectangle is much larger than the width. For example, here, continuing with the example where the pressure release area 213 is located on the bottom wall of the housing 211, FIG. 10 is a bottom view of the housing 211. As shown in FIG. 10, the second concave groove 2132 may be long-shaped. Similarly, the shape of the third concave groove 2133 in the embodiment of the present application may coincide with that of the first concave groove 2131 and the second concave groove 2132. Here, the long shape is also taken as an example.

[0111] Specifically, as shown in FIG. 10, the pressure release area 213 is long-shaped, that is, the length of the second concave groove 2132 located on the outer surface of the bottom wall of the housing 211 of the pressure release area 213 is much larger than the width, and the length of the third concave groove 2133 is also much larger than the width. For example, taking the third concave groove 2133 as an example, the length L1 of the bottom wall of the third concave groove 2133 may usually be set to 40 mm to 100 mm, for example, it may be set to 40 mm, 70 mm or 100 mm. In this way, the length of the long-shaped third concave groove 2133 is large, the opening area is large, the exhaust is smoother, the exhaust speed is high, and it is difficult for an explosion to occur.

[0112] FIG. 11 shows a cross-sectional view of the housing 211 in the embodiment of the present application. The upper side in FIG. 11 corresponds to the opening of the housing 211, the lower side in FIG. 11 is the bottom wall of the housing 211, and a pressure release region 213 is provided on the bottom wall of the housing 211. FIG. 12 is an enlarged view of region A2 in FIG. 11, and the pressure release region 213 is included in the region A2. The upper side in FIG. 12 corresponds to the inside of the housing 211, and the lower side in FIG. 12 corresponds to the outside of the housing 211. Specifically, as shown in FIG. 12, similar to FIG. 9, a first concave groove 2131 is provided on the inner surface of the housing 211, a second concave groove 2132 is provided on the outer surface of the housing 211, and a third concave groove 2133 is provided on the bottom wall of the second concave groove 2132. Different from FIG. 9, the cross-sectional shapes of the first concave groove 2131, the second concave groove 2132, and the third concave groove 2133 shown in FIG. 12 are not annular with a protruding structure in the middle.

[0113] Regarding the shapes of the cross-sections shown in FIG. 12 of the first concave groove 2131, the second concave groove 2132, and the third concave groove 2133 in the embodiment of the present application, FIG. 12 takes a rounded trapezoid as an example, but it may be set to other shapes according to actual applications. For example, regarding the angle formed by the bottom wall and the side wall of each concave groove, it may be a right angle, that is, the first concave groove 2131, the second concave groove 2132, and the third concave groove 2133 may be right-angled concave grooves. Or, since the bottom walls of the first concave groove 2131, the second concave groove 2132, and the third concave groove 2133 are all elongated and considering that it is very difficult to machine a right angle during the processing process, therefore, the first concave groove 2131, the second concave groove 2132, and the third concave groove 2133 may be concave grooves with an inclined angle as shown in FIG. 12, and be trapezoidal as a whole. For example, the rounded trapezoid in FIG. 12 is mentioned, that is, the area of the bottom wall of the first concave groove 2131, the second concave groove 2132, and the third concave groove 2133 is less than the area of the opening, but the embodiment of the present application is not limited thereto.

[0114] As shown in FIG. 12, similar to FIG. 9, regarding the outside of the housing 211, there may be further protrusions 2137 on the outer surface of the housing 211, surrounding the second concave groove 2132, and the protrusions 2137 extend in a direction away from the inside of the housing 211 with respect to the outer surface of the housing 211. For the sake of brevity, detailed description is omitted here.

[0115] As shown in FIG. 12, in order to protect the side of the pressure release region 213 away from the housing 211 from the influence of other members outside the battery case 21, similar to the first embodiment, the pressure release region 213 may further include a protective sheet 2135 that is used to protect the pressure release region 213, provided on the outer surface of the battery case 21 and covering the second concave groove 2132.

[0116] As can be understood, in the embodiments of the present application, the dimensions of each of the above parts may all be set according to actual applications. For example, the following will be exemplarily described with reference to FIG. 12.

[0117] Regarding the area of the pressure release region 213, the area of the bottom wall of the second concave groove 2132 is usually set to be equal to the area of the bottom wall of the first concave groove. For example, the area of the bottom wall of the first concave groove is usually set to 150 mm 2 ~330 mm 2 and may be set, for example, to 150 mm 2 , 200 mm 2 or 330 mm 2 and the area of the bottom wall of the second concave groove 2132 is also usually set to 150 mm 2 ~330 mm 2 and may be set, for example, to 150 mm 2 , 200 mm 2 or 330 mm 2 In addition, the width of the bottom wall of the first concave groove 2131 may be equal to the width of the bottom wall of the second concave groove 2132. For example, as shown in FIG. 12, the width L2 of the bottom wall of the first concave groove 2131 is equal to the width L2 of the bottom wall of the second concave groove 2132 and may be set to 3 mm to 6 mm, for example, 3 mm, 5 mm or 6 mm.

[0118] As shown in FIG. 12, here, taking the case where the pressure release region 213 is provided on the bottom wall of the housing 211 as an example, the thickness h11 of the bottom wall of the housing 211 may usually be set to 1.2 mm to 2 mm, for example, it may be set to 1.2 mm, 1.5 mm or 2 mm. The depth h12 of the first concave groove 2131 with respect to the inner surface of the battery case 21 may usually be set to 0.4 mm to 0.7 mm, for example, it may be set to 0.4 mm, 0.5 mm or 0.7 mm. The depth h13 of the second concave groove 2132 with respect to the outer surface of the battery case 21 is 0.3 mm to 0.6 mm, for example, it may be set to 0.3 mm, 0.5 mm or 0.6 mm. The thickness h14 at the third concave groove 2133 of the pressure release region 213 may usually be set to 0.16 mm to 0.25 mm, for example, it may be set to 0.16 mm, 0.2 mm or 0.25 mm.

[0119] Referring to the relevant dimensions of the above first concave groove 2131 and second concave groove 2132, such as depth and the area of the bottom wall, etc., as shown in FIG. 12, the height h15 by which the protrusion 2137 protrudes with respect to the outer surface of the battery case 21 may usually be set to 0.25 mm to 0.5 mm, for example, it may be set to 0.25 mm, 0.3 mm or 0.5 mm. The thickness h16 of the protective sheet 2135 may usually be set to 0.1 mm to 0.2 mm, for example, it may be set to 0.1 mm, 0.15 mm or 0.2 mm.

[0120] Above, the battery case, battery cell and battery in the embodiments of the present application have been described with reference to FIGS. 1 to 12. Hereinafter, the manufacturing method and apparatus of the battery case in the embodiments of the present application will be described with reference to FIGS. 13 and 14.

[0121] Specifically, FIG. 13 shows a schematic flowchart of a method 200 for manufacturing a battery case in an embodiment of the present application. As shown in FIG. 13, the method 200 includes S210, a step of forming a pressure release region of the battery case by installing a first concave groove on an inner surface of the battery case and a second concave groove on an outer surface of the battery case, wherein the first concave groove and the second concave groove are provided opposite to each other; and S220, a step of installing a third concave groove on a bottom wall of the first concave groove and / or a bottom wall of the second concave groove, wherein the pressure release region is configured to rupture at the third concave groove to release the internal pressure when the internal pressure of the battery case reaches a threshold value.

[0122] Optionally, as an embodiment, there is a protrusion on an outer surface of the battery case and the second concave groove surrounds the protrusion.

[0123] Optionally, as an embodiment, a shape of a bottom wall of the first concave groove and / or a shape of a bottom wall of the third concave groove is elongated.

[0124] Optionally, as an embodiment, the first concave groove and / or the second concave groove is an annular concave groove.

[0125] As can be understood, the method 200 in the embodiment of the present application can be used to manufacture the battery case 21 in the embodiment of the present application. For the sake of brevity, the detailed description is omitted here.

[0126] As can be understood, in various embodiments of the present application, the magnitude of the numbers of the above processes does not mean the priority order of the execution order, and the execution order of each process should be determined by its function and internal logic, and does not limit the implementation process of the embodiments of the present application.

[0127] FIG. 14 shows a schematic block diagram of a battery case manufacturing apparatus 300 according to an embodiment of the present application. As shown in FIG. 14, the apparatus 300 according to the embodiment of the present application includes an installation module 310. The installation module 310 is used to form a pressure release area of the battery case by installing a first concave groove on the inner surface of the battery case and a second concave groove on the outer surface of the battery case. The first concave groove and the second concave groove are provided opposite to each other, and are used to install a third concave groove on the bottom wall of the first concave groove and / or the bottom wall of the second concave groove. The pressure release area is configured to rupture at the third concave groove to release the internal pressure when the internal pressure of the battery case reaches a threshold value.

[0128] Optionally, as an embodiment, there is a protrusion on the outer surface of the battery case and surrounds the second concave groove.

[0129] Optionally, as an embodiment, the shape of the bottom wall of the first concave groove and / or the shape of the bottom wall of the third concave groove is elongated.

[0130] Optionally, as an embodiment, the first concave groove and / or the second concave groove is an annular concave groove.

[0131] As can be understood, the apparatus 300 in the embodiment of the present application can be executed in association with the method 200 in the embodiment of the present application, and the above and other operations and / or functions of each unit of the apparatus 300 are respectively for realizing the corresponding processes of the method 200 in FIG. 13. For the sake of brevity, the detailed description is omitted here.

[0132] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and do not limit them. Although the present application has been described in detail with reference to the above embodiments, as can be understood by those skilled in the art, it is still possible to change the technical solutions described in the above embodiments or equivalently replace some of the technical features among them. However, these changes and replacements do not deviate from the spirit and scope of the technical solutions of the present application corresponding to the technical solutions of each embodiment of the present application.

Description of Symbols

[0133] 10 Battery 11 Battery Module 20 Battery Cell 21 Battery Case 22 Electrode Assembly 23 Current Collector Member, Copper-Aluminum Adapter Sheet, Connection Member 24 Backing Plate 30 Controller 40 Motor 111 First Cover 112 Second Cover 200 Manufacturing Method 211 Battery Housing, Housing 212 Cover Plate 213 Pressure Release Region 214 Electrode Terminal 221 Positive Electrode Tab 222 Negative Electrode Tab 241 Avoidance Region 300 Manufacturing Apparatus 310 Installation Module 2131 First Groove 2132 Second Groove 2133 Third Groove 2134 Fourth Groove 2135 Protection Sheet 2136 Protrusion Structure 2137 Protrusion

Claims

1. A battery case comprising: a pressure release region, the pressure release region comprising a first groove provided on an inner surface of the battery case and a second groove provided on an outer surface of the battery case, the first groove and the second groove being provided opposite each other, the first groove and / or the second groove being annular grooves, a fourth annular groove being provided on a bottom wall of the second groove, and a third groove being provided on a bottom wall of the fourth groove, the pressure release region being configured to rupture at the third groove to release the internal pressure when an internal pressure of the battery case reaches a threshold value.

2. The battery case according to claim 1 , wherein the pressure release area has a thickness of 0.16 mm to 0.25 mm at the third groove.

3. The battery case according to claim 1 , wherein an axis perpendicular to the bottom wall of the first groove and an axis perpendicular to the bottom wall of the second groove are the same.

4. The battery case according to any one of claims 1 to 3, wherein a protrusion is provided on an outer surface of the battery case and surrounds the second groove.

5. 5. The battery case according to claim 4, wherein the height of the projection protruding from the outer surface of the battery case is 0.25 mm to 1 mm.

6. The area of ​​the bottom wall of the first groove is 400 mm ２ ~1000mm ２ and / or the area of ​​the bottom wall of the second groove is 600 mm ２ ~1200mm ２ The battery case according to any one of claims 1 to 5,

7. The battery case according to any one of claims 1 to 6, wherein the depth of the first groove relative to the inner surface of the battery case is 1 mm to 2 mm, and / or the depth of the second groove relative to the outer surface of the battery case is 0.3 mm to 0.6 mm.

8. The area of ​​the bottom wall of the fourth groove is 200 mm ２ ~800mm ２ The battery case according to any one of claims 1 to 7,

9. The battery case according to any one of claims 1 to 8, further comprising a protective sheet used to protect the pressure release area, the protective sheet being provided on an outer surface of the battery case and covering the second groove.

10. The battery case according to claim 9, wherein the protective sheet has a thickness of 0.1 mm to 0.2 mm.

11. A housing that is a hollow rectangular parallelepiped and has an opening at one end; a cover plate for covering an opening of the housing; The battery case according to any one of claims 1 to 10, comprising:

12. The battery case according to claim 11 , wherein the pressure release area is located in a bottom wall of the housing, the bottom wall of the housing being a wall facing the opening of the housing.

13. The battery case according to claim 12, wherein the thickness of the bottom wall of the housing is 1.2 mm to 2 mm.

14. A battery cell, The battery case according to any one of claims 1 to 13, an electrode assembly provided in the battery case; Equipped with The battery case is A housing that is a hollow rectangular parallelepiped and has an opening at one end; a cover plate for covering an opening of the housing; The battery cell includes: The battery cell further comprises a backing plate positioned between the electrode assembly and a bottom wall of the housing, the bottom wall of the housing being a wall of the housing facing the housing opening.

15. 15. The battery cell of claim 14, wherein the pressure release area is located on a bottom wall of the housing, and the backing plate has a through hole corresponding to the pressure release area, so that the backing plate does not cover the pressure release area.

16. A battery, A plurality of battery cells including at least one battery cell according to claim 14 or 15; A bus bar member used to realize electrical connection of the plurality of battery cells; a housing used to house the plurality of battery cells and the bus bar member; Equipped with a battery.

17. 17. A power consuming device comprising the battery of claim 16.

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