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

Abstract

A battery box, a battery cell (20), a battery (10), a method and a device for manufacturing a battery box (21). The battery box (21) comprises a pressure relief area (213) comprising a first groove (2131) arranged on an inner surface of the battery box (21) and a second groove (2132) arranged on an outer surface of the battery box (21), the first groove (2131) and the second groove (2132) being arranged oppositely, wherein a bottom wall of the first groove (2131) and / or a bottom wall of the second groove (2132) is provided with a third groove (2133), the pressure relief area (213) being configured to break at the third groove (2133) to release an internal pressure of the battery box (21) when the internal pressure reaches a threshold value. The pressure relief area arranged on the battery box is easy to process.

Description

[0001] This application is a divisional application of the invention application filed on July 10, 2020, with Chinese application number 202080096262.6 and entitled "Battery box, battery cell, battery, method and apparatus for preparing battery box". Technical Field

[0002] This application relates to the field of energy storage components, specifically to a battery box, a battery cell, a battery, and a method and apparatus for manufacturing the battery box. Background Technology

[0003] Lithium-ion batteries have advantages such as small size, high energy density, long cycle life and long storage time, and have been widely used in some electronic devices, electric vehicles and electric toys. For example, they are widely used in mobile phones, laptops, electric bicycles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and power tools.

[0004] With the continuous development of lithium-ion battery technology, higher requirements have been placed on the safety performance of lithium-ion batteries. The pressure relief mechanism on a lithium-ion battery has a significant impact on its safety performance. For example, when a lithium-ion battery experiences a short circuit or overcharging, it may lead to thermal runaway, causing a sudden increase in internal pressure. In this situation, the pressure relief mechanism needs to be activated to release the internal pressure outwards, thereby preventing the lithium-ion battery from exploding. Therefore, the design of the pressure relief mechanism is extremely important. Summary of the Invention

[0005] This application discloses a battery box, a battery cell, a battery, a method and apparatus for manufacturing the battery box, in order to improve battery performance.

[0006] According to a first aspect of this application, a battery box is provided, including a pressure relief region, the pressure relief region including a first groove disposed on the inner surface of the battery box and a second groove disposed on the outer surface of the battery box, the first groove being disposed opposite to the second groove, wherein the bottom wall of the first groove and / or the bottom wall of the second groove is provided with a third groove, the pressure relief region being configured to rupture at the third groove to release the internal pressure when the internal pressure of the battery box reaches a threshold.

[0007] The battery box in this embodiment of the application is provided with a pressure relief area, which includes a first groove and a second groove respectively provided on the inner and outer surfaces of the battery box. Furthermore, a third groove can be further provided on the bottom wall of the third and / or second groove of the first groove, so that the thickness of the third groove in the pressure relief area is thinner than the thickness of other areas of the battery box. In this way, when thermal runaway occurs inside the battery cell, the battery box can rupture at the relatively weak third groove to release the internal pressure. Moreover, the pressure relief area in this embodiment of the application is simpler to manufacture than the method of additionally installing a pressure relief mechanism on the battery box. For example, the first groove, the second groove and the third groove can be set by stamping, wherein the first groove and the second groove are arranged opposite to each other. Specifically, a punching method can be used to process two grooves at the same time. The manufacturing process is convenient and quick, and the size and shape of the three grooves are flexible and can be adjusted according to the actual application.

[0008] In some embodiments, the third groove is disposed on the bottom wall of the second groove.

[0009] Considering that the first groove is located on the inner surface of the battery box, if the third groove is located on the bottom wall of the first groove, the electrolyte inside the battery box will accumulate in the third groove and corrode the third groove, which may cause the pressure relief area to rupture prematurely at the third groove. Therefore, the third groove is usually located on the bottom wall of the second groove on the outer surface to avoid electrolyte corrosion.

[0010] In some embodiments, the thickness of the pressure relief region at the third groove is 0.16 mm to 0.25 mm.

[0011] In some embodiments, the axis perpendicular to the bottom wall of the first groove is the same as the axis perpendicular to the bottom wall of the second groove.

[0012] In other words, the first and second grooves are positioned opposite each other, which makes the structure of the pressure relief area relatively symmetrical, which is conducive to achieving more precise directional rupture in the pressure relief area.

[0013] In some embodiments, the outer surface of the battery box has a protrusion that surrounds the second groove.

[0014] Considering that if the first and second grooves are processed by stamping, there will usually be protrusions at the edges of the grooves. If these protrusions are located inside, they will affect the installation of the internal electrode components. Therefore, these protrusions can be located on the outer surface of the housing.

[0015] In some embodiments, the protrusion protrudes from the outer surface of the battery compartment by a height of 0.25 mm to 1 mm.

[0016] In some embodiments, the bottom wall of the first groove and / or the bottom wall of the second groove are elongated.

[0017] Long, narrow grooves are easier to process.

[0018] In some embodiments, the width of the bottom wall of the first groove and / or the width of the bottom wall of the second groove are 3 mm to 6 mm.

[0019] In some embodiments, the area of ​​the bottom wall of the first groove is 150 mm². 2 Up to 330mm 2 ; and / or, the area of ​​the bottom wall of the second groove is 150 mm². 2 Up to 330mm 2 .

[0020] In some embodiments, the depth of the first groove relative to the inner surface of the battery compartment is 0.4 mm to 0.7 mm; and / or, the depth of the second groove relative to the outer surface of the battery compartment is 0.3 mm to 0.6 mm.

[0021] In some embodiments, the bottom wall of the third groove is elongated.

[0022] In some embodiments, the length of the third groove is 40 mm to 100 mm.

[0023] In some embodiments, the first groove and / or the second groove are annular grooves.

[0024] In some embodiments, the area of ​​the bottom wall of the first groove is 400 mm². 2 Up to 1000mm 2 ; and / or, the area of ​​the bottom wall of the second groove is 600 mm². 2 Up to 1200mm 2 .

[0025] In some embodiments, the depth of the first groove relative to the inner surface of the battery compartment is 1 mm to 2 mm; and / or, the depth of the second groove relative to the outer surface of the battery compartment is 0.3 mm to 0.6 mm.

[0026] In some embodiments, the bottom wall of the second groove is provided with an annular fourth groove, and the third groove is provided on the bottom wall of the fourth groove.

[0027] To facilitate rupture of the pressure relief area in the event of thermal runaway within the battery cell, the thickness of the third groove should be made thinner, allowing rupture to occur at this third groove within the pressure relief area, thus achieving more precise directional rupture and venting. A fourth groove is formed within the second groove, and a third groove is then formed on the bottom wall of the fourth groove, making it easier to obtain a thinner third groove area.

[0028] In some embodiments, the area of ​​the bottom wall of the fourth groove is 200 mm². 2 Up to 800mm 2 .

[0029] In some embodiments, the battery box further includes a protective sheet for protecting the pressure relief area, disposed on the outer surface of the battery box and covering the second groove.

[0030] In some embodiments, the thickness of the protective sheet is 0.1 mm to 0.2 mm.

[0031] A protective plate located on the side of the pressure relief area away from the inside of the battery compartment can protect the pressure relief area from the influence of external components.

[0032] In this embodiment, the pressure relief area is formed by a groove. Therefore, when the protective sheet is placed on the outer surface of the battery box and covers the second groove, there is a gap between the protective sheet and the pressure relief area. In this way, when the pressure relief area is venting, the gap between the protective sheet and the pressure relief area can ensure that the pressure relief area has a certain opening space, and can also prevent the protective sheet from causing wear to the pressure relief area when it is attached to the pressure relief area, thus further protecting the pressure relief area.

[0033] In some embodiments, the battery box includes: a housing, the housing being a hollow cuboid with an opening at one end; and a cover plate, which covers the opening of the housing.

[0034] In some embodiments, the pressure relief area is located on the bottom wall of the housing, which is a wall opposite to the opening of the housing.

[0035] Considering that the electrode terminals are typically located on the battery box cover, if the pressure relief area were also located on the cover, a thermal runaway within the battery cell could cause the pressure relief area to rupture. This would release the internal pressure of the battery cell and eject flammable liquids or solids, potentially including conductive materials, leading to a short circuit between the electrode terminals. Furthermore, since batteries are usually installed in vehicles with the electrode terminals facing upwards, towards the passengers, if the pressure relief area were located on the same side as the electrode terminals, the released gas and other substances would rise after the pressure relief area ruptures, potentially causing burns or scalds to passengers, increasing their risk. Therefore, placing the pressure relief area on the bottom wall of the casing, with the gas venting downwards, avoids these problems.

[0036] In some embodiments, the thickness of the bottom wall of the housing is 1.2 mm to 2 mm.

[0037] In some embodiments, the battery box further includes electrode terminals, the electrode terminals including a positive electrode terminal and a negative electrode terminal both disposed on the cover plate.

[0038] According to a second aspect of this application, a battery cell is provided, comprising: a battery box as described in the first aspect and any possible implementation thereof; and an electrode assembly disposed within the battery box.

[0039] In some embodiments, the battery box includes: a housing, the housing being a hollow cuboid with an opening at one end; and a cover plate, which covers the opening of the housing.

[0040] In some embodiments, the battery cell further includes a pad located between the electrode assembly and the bottom wall of the housing, the bottom wall of the housing being the wall of the housing opposite to the opening of the housing.

[0041] The pad also protects the pressure relief area, preventing the electrode components and electrode fluid inside the battery box from impacting the pressure relief area.

[0042] In some embodiments, the pressure relief area is located on the bottom wall of the housing, and the pad is provided with a through hole corresponding to the pressure relief area so that the pad does not obstruct the pressure relief area.

[0043] When the pressure relief area is located on the bottom wall, if the strength of the pressure relief area can ensure that the electrode assembly and electrode fluid will not damage it, then when thermal runaway occurs inside the battery cell, considering that the pad may block the gas from breaking through the pressure relief area, in order to make the pressure relief area easier to break, a part of the pad can be removed to form a clearance area. For example, a through hole can be set on the pad at the location of the pressure relief area so that the pad will not block the pressure relief area.

[0044] According to a third aspect of this application, a battery is provided, comprising: a plurality of battery cells, wherein the plurality of battery cells includes at least one battery cell as described in the second aspect above and any possible implementation thereof; a busbar for electrically connecting the plurality of battery cells; and a housing for accommodating the plurality of battery cells and the busbar.

[0045] According to a fourth aspect of this application, an electrical device is provided, comprising: a battery as described in the third aspect above.

[0046] This electrical equipment can be used in vehicles, ships, or spacecraft.

[0047] According to a fifth aspect of this application, a method for manufacturing a battery box is provided, comprising: providing a first groove on the inner surface of the battery box and providing a second groove on the outer surface of the battery box to form a pressure relief region of the battery box, wherein the first groove and the second groove are disposed opposite to each other; providing a third groove on the bottom wall of the first groove and / or the bottom wall of the second groove, wherein the pressure relief region is configured to rupture at the third groove to release the internal pressure when the internal pressure of the battery box reaches a threshold.

[0048] In some embodiments, the outer surface of the battery box has a protrusion that surrounds the second groove.

[0049] In some embodiments, the bottom wall of the first groove and / or the bottom wall of the third groove are elongated.

[0050] In some embodiments, the first groove and / or the second groove are annular grooves.

[0051] It should be understood that the method for preparing the battery box in the embodiments of this application can be used to prepare the battery box in the first aspect and any possible implementation of the first aspect.

[0052] According to a sixth aspect of this application, an apparatus for manufacturing a battery box is provided, comprising: a setting module, the setting module being configured to: provide a first groove on the inner surface of the battery box and a second groove on the outer surface of the battery box to form a pressure relief region of the battery box, wherein the first groove and the second groove are disposed opposite to each other; and to provide a third groove on the bottom wall of the first groove and / or the bottom wall of the second groove, wherein the pressure relief region is configured to rupture at the third groove to release the internal pressure when the internal pressure of the battery box reaches a threshold.

[0053] In some embodiments, the outer surface of the battery box has a protrusion that surrounds the second groove.

[0054] In some embodiments, the bottom wall of the first groove and / or the bottom wall of the third groove are elongated.

[0055] In some embodiments, the first groove and / or the second groove are annular grooves.

[0056] It should be understood that the apparatus for manufacturing the battery box according to the embodiments of this application can be used to perform the methods in the fifth aspect or any possible implementation of the fifth aspect described above. Specifically, the apparatus includes units for performing the methods in the fifth aspect or any possible implementation of the fifth aspect described above. Attached Figure Description

[0057] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0058] Figure 1 A schematic diagram of the exterior of some embodiments of a vehicle using the battery of this application;

[0059] Figure 2 These are schematic diagrams illustrating the structure of some embodiments of the battery in this application;

[0060] Figure 3 This is a schematic diagram of the structure of some embodiments of the battery module in the battery of this application;

[0061] Figure 4 These are exploded views of some embodiments of the battery cell of this application;

[0062] Figure 5 Schematic diagrams of some embodiments of the battery box with a pressure relief area according to this application;

[0063] Figure 6 These are exploded views of some other embodiments of the battery cell of this application;

[0064] Figure 7 Schematic diagrams of some embodiments of the pads in this application;

[0065] Figure 8 Cross-sectional views of some embodiments of the housing of the battery box of this application;

[0066] Figure 9 for Figure 8 A magnified view of region A1 in the image;

[0067] Figure 10 Bottom views of some embodiments of the battery box housing of this application;

[0068] Figure 11 for Figure 10 Cross-sectional views of some embodiments shown;

[0069] Figure 12 for Figure 11 A magnified view of region A2 in the image;

[0070] Figure 13 A schematic flowchart illustrating some embodiments of the method for preparing the battery box according to this application;

[0071] Figure 14 The diagram shows some embodiments of the apparatus for preparing the battery box according to this application. Detailed Implementation

[0072] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0073] 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 in the specification 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 drawings of this application, are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, not to describe a particular order or hierarchy.

[0074] 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.

[0075] In this article, 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: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0076] In this application, "multiple" refers to two or more (including two), and similarly, "multiple groups" refers to two or more (including two), and "multiple pieces" refers to two or more (including two).

[0077] The battery boxes, battery cells, and batteries comprising multiple battery cells described in this application are applicable to various battery-using devices, such as mobile phones, portable devices, laptops, electric vehicles, electric cars, ships, spacecraft, electric toys, and power tools. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers.

[0078] The battery box, battery cell, and battery including multiple battery cells described in the embodiments of this application are not limited to the devices described above, but can also be applied to all devices that use batteries. However, for the sake of brevity, the following embodiments are all illustrated using electric vehicles as an example.

[0079] For example, such as Figure 1The diagram shown is a structural schematic of a vehicle 1 according to an embodiment of this application. The vehicle 1 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 10 can be installed inside the vehicle 1. The battery 10 can be a battery pack or a battery module. For example, the battery 10 can be installed at the bottom, front, or rear of the vehicle 1. A controller 30 and a motor 40 can also be installed inside the vehicle 1. The battery 10 can be used to power the vehicle 1. For example, the battery 10 can serve as the operating power source for the vehicle 1's electrical system, such as meeting the power requirements for starting, navigation, and operation of the vehicle 1. In another embodiment of this application, the battery 10 can not only serve as the operating power source for the vehicle 1 but also as the driving power source for the vehicle 1, replacing or partially replacing gasoline or natural gas to provide driving power for the vehicle 1.

[0080] To meet different power demands, battery 10 may include one or more battery modules (or battery groups), wherein the multiple battery modules may be connected in series, parallel, or a combination thereof, with the latter referring to a mixture of series and parallel connections. For example, as... Figure 2 The diagram shown is a structural schematic of a battery 10 according to another embodiment of this application. The battery 10 includes a first cover 111, a second cover 112, and a plurality of battery modules 11. The shapes of the first cover 111 and the second cover 112 can be determined according to the shape of the combination of one or more battery modules 11. The first cover 111 and the second cover 112 each have an opening. For example, the first cover 111 and the second cover 112 can both be hollow cuboids and each has only one side as an opening, that is, this side does not have a shell wall so that the inside and outside of the shell are connected. The first cover 111 and the second cover 112 are fastened together at the opening to form a closed shell of the battery 10. One or more battery modules 11 are connected in parallel, series, or mixed and placed inside the shell formed by the fastening of the first cover 111 and the second cover 112.

[0081] In another embodiment of this application, when the battery 10 includes a battery module 11, the battery module 11 is placed inside the outer shell formed by the first cover 111 and the second cover 112 being fastened together.

[0082] The electricity generated by the one or more battery modules 11 is led out through the housing via a conductive mechanism (not shown).

[0083] In addition, the battery 10 may include other structures, which will not be described in detail here. For example, the battery 10 may also include a busbar component for realizing electrical connection between multiple battery cells (not shown); as another example, the battery 10 may also include a cooling component for containing a cooling medium to cool one or more battery modules 11, but the embodiments of this application are not limited to this.

[0084] Depending on different power requirements, the battery module 11 may include one or more individual battery cells, for example, such as Figure 3 As shown, a battery module 11 may include multiple battery cells 20. These battery cells 20 can be connected in series, parallel, or a combination thereof to achieve a larger capacity or power. The number of battery cells 20 included in a battery module 11 can 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 be cylindrical, flat, cuboid, or other shapes.

[0085] In another embodiment of this application, multiple battery cells 20 can be stacked together, and the multiple battery cells 20 can be connected in series, in parallel or in a mixed manner. In another embodiment of this application, each battery cell 20 can be square, cylindrical or other shapes.

[0086] Each battery cell 20 may include a battery box and an electrode assembly disposed within the battery box. The battery box may include two parts: a housing and a cover plate. The housing may be a hollow cuboid, cube, or cylinder, and one side of the housing has an opening so that the electrode assembly can be placed inside the housing. The cover plate is connected to the housing at the opening of the housing to form a closed battery box for the battery cell 20, and the housing may be filled with electrolyte.

[0087] In addition, the battery box includes two electrode terminals, which are typically mounted on the cover plate and connected to the electrode assembly. A pressure relief mechanism can also be installed on the flat surface of the cover plate; this mechanism can be part of the flat surface of the cover plate or welded to it. Under normal conditions, the pressure relief mechanism is sealed to the cover plate, forming the battery box of the battery cell 20 through the cover plate's connection to the housing at the opening. The space formed by this battery box is airtight. When too much gas is generated by the battery cell 20, the gas expands, causing the pressure inside the battery box to rise above a preset value. At this point, the pressure relief mechanism can rupture, allowing communication between the inside and outside of the battery box. The gas is released outwards through the rupture, thus preventing an explosion.

[0088] Currently, battery cells typically have their pressure relief mechanisms located on the cover, on the same side as the electrode terminals. When thermal runaway occurs inside the battery cell, the pressure relief mechanism ruptures, releasing internal pressure and ejecting liquid or solid combustibles, including potentially conductive materials, which can cause short circuits between the electrode terminals. Furthermore, considering that batteries are usually installed in vehicles with the electrode terminals facing upwards, towards the passengers, if the pressure relief mechanism is located on the same side as the electrode terminals, the released gas and other substances after rupture will rise upwards, potentially causing burns or scalds to passengers, increasing the risk of injury. Therefore, it is advisable to consider installing the pressure relief mechanism in other locations to address these issues, such as on the housing beneath the cover, for example, by mounting it on the bottom wall of the housing.

[0089] However, if the pressure relief mechanism is installed on the housing, the housing is a hollow structure with one open end, while the pressure relief mechanism is usually plate-shaped. This can lead to installation difficulties, especially when installing it on the bottom wall of the housing, where the depth of the housing makes it difficult to directly weld the plate-shaped pressure relief mechanism to the bottom wall. Therefore, embodiments of this application provide a battery box with a pressure relief area, which solves the above problems.

[0090] Specifically, still in the form of Figure 1-3 The illustrated embodiment is an example. Figure 4 Another embodiment of the battery cell 20 according to this application is shown. For example... Figure 4 As shown, the battery cell 20 includes a battery box (not shown), one or more electrode assemblies 22, and a connecting member 23. In this embodiment, the battery box includes a housing 211 and a cover plate 212.

[0091] Specifically, such as Figure 4 As shown, the battery case of the battery cell 20 includes a housing 211 whose shape can be determined by the combination of one or more electrode assemblies 22. For example, the housing 211 can be a hollow cuboid, cube, or cylinder, and one side of the housing 211 has an opening so that one or more electrode assemblies 22 can be placed inside the housing 211. For example, when the housing 211 is a hollow cuboid or cube, one of the planes of the housing 211 is an opening, that is, this plane does not have a housing wall, allowing communication between the inside and outside of the housing 211. When the housing 211 can be a hollow cylinder, the circular side of the housing 211 is an opening, that is, this circular side does not have a housing wall, allowing communication between the inside and outside of the housing 211. The cover plate 212 is connected to the housing 211 at the opening to form a closed battery case, and the housing 211 is filled with electrolyte.

[0092] like Figure 4As shown, the battery box of the battery cell 20 may also include two electrode terminals 214, which may be disposed on the cover plate 212. The cover plate 212 is usually flat, and the two electrode terminals 214 are located on the flat surface of the cover plate 212 and pass through the flat surface of the cover plate 212. The two electrode terminals 214 are positive electrode terminal 214a and negative electrode terminal 214b, respectively. Each electrode terminal 214 is provided with a corresponding connecting member 23, or it may also be called a current collector 23, or a copper-aluminum adapter piece 23, which is located between the cover plate 212 and the electrode assembly 22.

[0093] like Figure 4 As shown, each electrode assembly 22 may specifically include at least one positive electrode tab 221 and at least one negative electrode tab 222. Additionally, the electrode assembly 22 may also include a bare battery cell and an insulating sheet encasing the bare battery cell. Figure 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 an electrode terminal through a connecting member 23, and the negative electrode tab 222 of the one or more electrode assemblies 22 is connected to another electrode terminal through another connecting member 23. For example, the positive electrode terminal 214a is connected to the positive electrode tab 221 through a connecting member 23, and the negative electrode terminal 214b is connected to the negative electrode tab 222 through another connecting member 23.

[0094] In this battery cell 20, depending on actual usage requirements, the electrode assembly 22 can be configured as a single unit or multiple units, such as... Figure 4 As shown, at least two independent electrode assemblies 22 are provided within the battery cell 20.

[0095] In the battery cell 20, the electrode assembly 22 can be a wound structure or a stacked structure, and the embodiments of this application are not limited to this.

[0096] In addition, such as Figure 4 As shown, the battery cell 20 may further include a pad 24, which is located between the electrode assembly 22 and the bottom wall of the housing 211. The pad 24 supports the electrode assembly 22 and effectively prevents interference between the electrode assembly 22 and the rounded corners around the bottom wall of the housing 211. The shape of the pad 24 in this embodiment can be customized according to the actual application. For example, the pad 24 can be a rectangle with the same shape as the bottom wall of the housing 211, or... Figure 4As shown, it can also be set to other shapes; in addition, the pad 24 can be provided with one or more through holes. For example, multiple through holes can be provided in a uniform or symmetrical arrangement, so that the space between the upper and lower surfaces of the pad 24 can be connected, and the electrolyte and the gas generated inside the electrode assembly 22 and the electrolyte can pass freely through the pad 24 to facilitate liquid conduction and gas conduction.

[0097] The thickness of the pad 24 is generally set to 0.3-5mm, and it is preferably an insulating component, but it can also be non-insulating. For example, the material of the pad 24 can be PP, PE, PET, PPS, Teflon, stainless steel, aluminum, etc., which are both resistant to electrolytes and insulating. Among them, plastic materials such as PP, PE, PET, and PPS can be selected as fire-retardant materials, and the surface of metal materials such as aluminum or stainless steel can be anodized for insulation.

[0098] In addition, the battery cell 20 in this embodiment may also include other components. For example, the battery cell 20 may also include at least one of a top cover patch, a sealing pin, and a plastic pin, wherein the top cover patch, sealing pin, and plastic pin can be installed on the cover plate 212; in addition, the battery cell 20 may also include a blue film disposed on the outer surface of the battery casing 211 to achieve the function of insulation and protection of the battery cell. However, the embodiments of this application are not limited to these.

[0099] In this embodiment of the application, a pressure relief area may also be provided on the housing 211 or cover 212 of the battery box, for example, Figure 4 The pressure relief area can be provided on the bottom wall of the casing 211. Specifically, with Figure 5 For example, Figure 5 A schematic diagram of the battery box 21 is shown in this embodiment of the application. Figure 5 The battery box 21 includes, for example, Figure 4 The housing 211 and cover plate 212 are shown. Figure 5 As shown, the battery box 21, which is a cuboid (i.e., a hexahedron), is used as an example for explanation. This battery box 21 includes six walls (or six faces). Figure 5 The diagram shows any three adjacent walls of the battery compartment 21, while the pressure relief region 213 in this embodiment can be located on any one wall of the battery compartment 21. For example, the pressure relief region 213 can be located on the bottom wall of the housing 211 of the battery compartment 21, with the bottom wall of the housing 211 opposite to the opening of the housing 211. Figure 5 The wall of the battery box 21, which has a pressure relief area 213, represents the bottom wall of the housing 211; for example, such as Figure 6As shown, the pressure relief region 213 can also be provided on any side wall of the housing 211, but the embodiments of this application are not limited thereto. In this embodiment, the pressure relief region 213 is used to actuate and release the internal pressure when the internal pressure of the battery box 21 reaches a threshold.

[0100] In this embodiment, the battery box 21 is a cuboid, and the housing 211 has four sidewalls: two larger sidewalls and two smaller sidewalls. When the pressure relief area 213 is located on the sidewall of the housing 211, the pressure relief area 213 is typically located on the smaller sidewall, for example... Figure 6 As shown. Considering the assembly of multiple battery cells into a battery, for example, as... Figure 3 In the installation method shown, for a cuboid battery cell, the placement of two adjacent battery cells usually involves the larger sidewall of the two battery cells contacting each other. Therefore, if the pressure relief area 213 is located on the larger sidewall, arranging multiple battery cells closely together to assemble a battery will affect the opening of the pressure relief area 213. For example, space needs to be left between the battery cells for the pressure relief area 213 to open, which is not conducive to the installation of multiple battery cells. Therefore, installing the pressure relief area 213 on the smaller sidewall is beneficial for the placement of multiple battery cells and can further improve the energy density of the battery.

[0101] When the pressure relief area 213 is located on the bottom wall of the housing 211, considering the pressure exerted by the internal electrode assembly 22 on the pressure relief area 213, such as in a battery installed in a vehicle, where there will be bumps during vehicle operation, the electrode assembly 22 and electrolyte will impact the side and bottom walls of the housing 211. Since the pressure relief area 213 is thinner than other areas of the bottom wall of the housing, therefore... Figure 4 The pad 24 shown, which is provided between the electrode assembly 22 and the bottom wall of the housing 211, can buffer the pressure relief area 213 below to prevent the electrolyte and electrode assembly 22 from impacting the pressure relief area 213 and causing it to break.

[0102] However, on the other hand, the pad 24 on the bottom wall covers the pressure relief area 213. While protecting the pressure relief area 213, it may also prevent the pad 24 from blocking the gas from breaking through the pressure relief area 213. Therefore, a clearance area can also be set on the pad 24 to ensure that the pad does not block the pressure relief area 213. In other words, whether to set a clearance area on the pad 24 can be selected according to factors such as the thickness and strength of the pressure relief area 213 in actual application.

[0103] Specifically, in cases where a clearance zone is provided on the pad 24 to ensure that the pad does not obstruct the pressure relief area 213, such as... Figure 7As shown, taking a rectangular pad 24 as an example, a portion of the pad 24 can be removed. Specifically, a through hole is provided on the pad 24 at the location of the pressure relief area 213 as a clearance area 241, ensuring that the pad 24 does not obstruct the pressure relief area. The shape of the clearance area 241 on the pad 24 is typically consistent with the shape of the surface of the pressure relief area 213 closest to the interior of the housing 211. Figure 7 This is merely an example, and the embodiments described in this application are not limited thereto.

[0104] Furthermore, in order to ensure that the pad 24 does not completely obstruct the pressure relief area 213, the area of ​​the clearance area 241 of the pad 24 is usually set to be larger than the area of ​​the pressure relief area 213; or, considering that the pressure relief area 213 in this embodiment is located in the through hole of the bottom wall of the housing 211, the area of ​​the clearance area 241 of the pad 24 is larger than the area of ​​the through hole of the bottom wall of the housing 211, but this embodiment is not limited to this.

[0105] The pressure relief region 213 in the embodiments of this application will now be described in detail with reference to the accompanying drawings. Specifically, this will be exemplified by setting the pressure relief region 213 on the bottom wall of the housing 211. Figure 8 A cross-sectional view of the housing 211 in an embodiment of this application is shown. For example, the surface shown in the cross-sectional view may be a surface that passes through the pressure relief region 213 and is parallel to a small sidewall of the housing 211. Figure 9 for Figure 8 An enlarged view of region A1, which includes pressure relief region 213, wherein... Figure 9 The upper part corresponds to the interior of the shell 211. Figure 9 The lower part corresponds to the outside of the housing 211. Specifically, as shown in... Figure 9 As shown, the pressure relief region 213 in this embodiment may include a first groove 2131 disposed on the inner surface of the housing 211 of the battery box 21 and a second groove 2132 disposed on the outer surface of the housing 211 of the battery box 21. The first groove 2131 and the second groove 2132 are disposed opposite to each other. The bottom wall of the first groove 2131 and / or the bottom wall of the second groove 2132 are provided with a third groove 2133. The pressure relief region 213 is configured to rupture at the third groove 2133 to release the internal pressure when the internal pressure of the battery box 21 reaches a threshold.

[0106] Thus, when thermal runaway occurs inside a battery cell, the battery box 21 can rupture at the relatively weak third groove 2133 to release internal pressure. Furthermore, the pressure relief area 213 in this embodiment is simpler to manufacture than an additional pressure relief mechanism installed on the battery box 21. For example, the first groove 2131, the second groove 2132, and the third groove 2133 can be formed by stamping, with the first groove 2131 and the second groove 2132 facing each other. Specifically, a punching method can be used to process two grooves simultaneously, making the manufacturing process convenient and quick. Moreover, the size and shape of the three grooves are flexible and can be adjusted according to actual applications. Furthermore, since the housing 211 is typically made of aluminum, the pressure relief area 213 is also made of aluminum. Compared to additional pressure relief mechanisms made of other materials, the pressure relief area 213 in this embodiment is easier to manufacture and can easily open promptly when thermal runaway occurs inside the battery box 21, resulting in smoother and higher venting rates.

[0107] Furthermore, considering that the electrode terminals 214 are typically located on the cover plate 212 of the battery box 21, if the pressure relief area 213 is also located on the cover plate 212, then when thermal runaway occurs inside the battery cell 20, the pressure relief area 213 will rupture, releasing the internal pressure of the battery cell 20 and ejecting liquid or solid combustibles, which may include conductive materials, leading to a short circuit between the electrode terminals 214. Simultaneously, considering that when the battery is installed in a vehicle, the electrode terminals 214 are usually facing upwards, i.e., towards the passengers, if the pressure relief area 213 is located on the same side as the electrode terminals 214, the gas and other substances released after the pressure relief area 213 ruptures will be emitted upwards, potentially causing burns or scalds to passengers, increasing the risk to passengers. Therefore, in this embodiment, the pressure relief area 213 can be flexibly located on the bottom wall or side wall of the battery box 21's housing 211, without being limited by the manufacturing process.

[0108] In this embodiment, the third groove 2133 can be disposed on the bottom wall of the first groove 2131 and / or the bottom wall of the second groove 2132. However, considering that the first groove 2131 is disposed on the inner surface of the battery box 21, if the third groove 2133 is disposed on the bottom wall of the first groove 2131, the electrolyte present in the battery box 21 will accumulate in the third groove 2133, corroding part of the third groove 2133. This may cause the pressure relief area 213 to rupture prematurely at the third groove 2133. Therefore, the third groove 2133 is usually disposed on the bottom wall of the second groove 2132 located on the outer surface to avoid electrolyte corrosion. The following description uses the example of the third groove 2133 being disposed on the bottom wall of the second groove 2132.

[0109] It should be understood that the first groove 2131 and the second groove 2132 in the embodiments of this application are positioned opposite each other, or in other words, the positions of the first groove 2131 and the second groove 2132 are opposite each other in the direction perpendicular to the pressure relief area. For example, relative to the inner surface where the first groove 2131 of the battery box 21 is located, the projection of the second groove 2132 on the inner surface and the projection of the bottom wall of the first groove 2131 on the inner surface are at least partially overlapping. For example, the following description assumes that the first groove 2131 and the second groove 2132 are directly opposite each other, that is, the axis perpendicular to the bottom wall of the first groove 2131 is the same as the axis perpendicular to the bottom wall of the second groove 2132.

[0110] The shapes of the bottom walls of the first groove 2131 and the second groove 2132 in the pressure relief area 213 of this application embodiment can be set according to actual applications, and the shapes of the bottom walls of the first groove 2131 and the second groove 2132 can be the same or different. For ease of explanation, the following description uses the example of the bottom walls of the first groove 2131 and the second groove 2132 having the same shape. The shapes of the bottom walls of the first groove 2131 and the second groove 2132 can be rectangular, circular, elliptical, or annular. These will be described in detail below with reference to two embodiments.

[0111] Optionally, as a first embodiment, such as Figure 8 and 9 As shown, the shape of the bottom wall of the first groove 2131 and the shape of the bottom wall of the second groove 2132 can be annular, for example, a square ring, a circular ring, or other annular shapes. For example, here we take... Figure 5 Taking the runway-shaped ring shown as an example, the runway shape is similar to an ellipse, with rounded ends but a straight line in the middle, but the embodiments of this application are not limited to this.

[0112] like Figure 9 As shown, to facilitate processing, providing a third groove 2133 on the bottom wall of the second groove 2132 may include: the bottom wall of the second groove 2132 being provided with a fourth groove 2134, and the third groove 2133 being disposed on the bottom wall of the fourth groove 2134. Considering that the bottom wall of the second groove 2132 is annular, the shape of the bottom wall of the fourth groove 2134 can be consistent with the shape of the bottom wall of the second groove 2132, also being annular, but the embodiments of this application are not limited to this.

[0113] like Figure 9 As shown, in the embodiments of this application, the first groove 2131, the second groove 2132, the third groove 2133, and the fourth groove 2134 are in Figure 9The shape of the cross-section shown can be set according to the actual application. For example, the angle formed by the bottom wall and side wall of the groove can be... Figure 9 The right-angled grooves shown in the second groove 2132 and the fourth groove 2134, or as shown in the image. Figure 9 The first groove 2131 and the third groove 2133 shown are grooves with inclined angles, but the embodiments of this application are not limited thereto.

[0114] like Figure 9 As shown, since the first groove 2131 and the second groove 2132 are annular grooves, there will be a protruding structure in their central area. Here, we take the protruding structure 2136 near the inside of the housing 211 as an example. The protruding structure 2136 is in the middle area of ​​the annular first groove 2131. The surface of the protruding structure 2136 near the housing 211 can be non-protruding relative to the inner surface of the housing 211 except for the pressure relief area 213. For example, the surface of the protruding structure 2136 near the housing 211 can be basically flush with the inner surface of the housing 211 except for the pressure relief area 213, or, as... Figure 9 As shown, the surface of the protruding structure 2136 near the housing 211 may also be recessed relative to the inner surface of the housing 211 other than the pressure relief area 213, and the embodiments of this application are not limited thereto.

[0115] Meanwhile, the outer periphery of the first groove 2131 does not protrude relative to the inner surface of the housing 211. In this way, there will be no protruding parts on the inner surface of the housing 211. When installing components such as electrode assemblies inside the housing 211, it will not be affected and no additional design is needed to avoid the protruding parts, thereby saving internal space.

[0116] like Figure 9 As shown, for the exterior of the housing 211, a protrusion 2137 may also be provided around the second groove 2132 on the outer surface of the housing 211. The protrusion 2137 extends away from the interior of the housing 211 relative to the outer surface of the housing 211. Considering that if the first groove 2131 and the second groove 2132 are processed by stamping, there will usually be a protrusion at the edge of the groove. If the protrusion is located inside, it will affect the installation of the internal electrode assembly. Therefore, the protrusion 2137 can be provided on the outer surface of the housing 211.

[0117] Assuming that when the battery cell 20 is assembled into the battery 10, a component needs to be placed below the battery cell 20, such as a cooling plate for cooling the battery cell 20, or a bottom protective plate, the embodiments of this application are not limited to these. Due to the presence of the protrusion 2137, for the component located below the battery cell 20, a recessed avoidance area can be provided on the surface to assemble the battery cell 20. For example, if a cooling plate is provided below the battery cell 20, a groove or through hole can be provided on the area of ​​the cooling plate corresponding to the pressure relief area 213, so that the protrusion 2137 in the pressure relief area 213 can be accommodated in the groove or through hole, thereby saving space.

[0118] In addition, due to the presence of the protrusion 2137, there is a gap between the surface of the pressure relief area 213 away from the interior of the housing 211 and the surface of the component located below the pressure relief area 213 (such as the cooling component or the bottom guard plate). Therefore, the pressure relief area 213 can have a certain opening space when venting, ensuring that the third groove 2133 of the pressure relief area 213 can break and open to release the internal pressure.

[0119] like Figure 9 As shown, in order to protect the side of the pressure relief area 213 away from the housing 211 from the influence of other components outside the battery box 21, the pressure relief area 213 may also include: a protective sheet 2135, which is provided on the outer surface of the battery box 21 and covers the second groove 2132 to protect the pressure relief area 213.

[0120] It should be understood that the dimensions of each part in the embodiments of this application can be set according to actual applications. For example, the following is combined with Figure 9 Let's illustrate with examples.

[0121] For the size of the pressure relief area 213, the area of ​​the bottom wall of the first groove can typically be set to 400 mm². 2 Up to 1000mm 2 For example, it can be set to 400mm 2 700mm 2 Or 1000mm 2 The area of ​​the bottom wall of the second groove 2132 can typically be set to 600 mm². 2 Up to 1200mm 2 For example, it can be set to 600mm 2 900mm 2 Or 1200mm 2 The area of ​​the bottom wall of the fourth groove 2134 can typically be set to 200 mm². 2 Up to 800mm 2 For example, it can be set to 200mm 2500mm 2 Or 800mm 2 In this application embodiment, "mm" 2 "" indicates square millimeters.

[0122] like Figure 9 As shown, taking the pressure relief area 213 located on the bottom wall of the housing 211 as an example, the thickness h1 of the bottom wall of the housing 211 can typically be set to 1.2mm to 2mm, for example, it can be set to 1.2mm, 1.5mm, or 2mm; the depth h2 of the first groove 2131 relative to the inner surface of the battery box 21 can typically be set to 1mm to 2mm, for example, it can be set to 1mm, 1.5mm, or 2mm; the depth h3 of the second groove 2132 relative to the outer surface of the battery box 21 is 0.3mm. The thickness h4 between the bottom wall of the second groove 2132 and the bottom wall of the first groove 2131 can typically be set to 0.3mm to 1mm, for example, 0.3mm, 0.5mm, or 1mm; the thickness h5 of the pressure relief area 213 at the third groove 2133 can typically be set to 0.16mm to 0.25mm, for example, 0.16mm, 0.2mm, or 0.25mm. In this embodiment, "mm" represents millimeters.

[0123] like Figure 9 As shown, referring to the relevant dimensions of the first groove 2131 and the second groove 2132, such as depth and bottom wall area, the height h6 of the protrusion 2137 protruding from the outer surface of the battery box 21 can usually be set to 0.5mm to 1mm, for example, it can be set to 0.5mm, 0.8mm or 1mm; in addition, the thickness h7 of the protective sheet 2135 can usually be set to 0.1mm to 0.2mm, for example, it can be set to 0.1mm, 0.15mm or 0.2mm.

[0124] Optionally, as a second embodiment, the shape of the bottom wall of the first groove 2131 and the shape of the bottom wall of the second groove 2132 can also be set to other shapes, such as rectangles, circles, or racetrack shapes. Here, we take a long strip shape as an example. The long strip shape refers to a special type of rectangle, that is, the length of the rectangle is much greater than its width. For example, we still take the example that the pressure relief area 213 is located on the bottom wall of the shell 211. Figure 10 This is a bottom view of housing 211, as shown below. Figure 10 As shown, the second groove 2132 can be elongated. Similarly, the shape of the third groove 2133 in this embodiment can also be consistent with the first groove 2131 and the second groove 2132, and here we also take an elongated shape as an example.

[0125] Specifically, such as Figure 10 As shown, the pressure relief area 213 is elongated, meaning that the length of the second groove 2132 located on the outer surface of the bottom wall of the housing 211 in the pressure relief area 213 is much greater than its width, and the length of the third groove 2133 is also much greater than its width. For example, taking the third groove 2133 as an example, the length L1 of the bottom wall of the third groove 2133 can usually be set to 40mm to 100mm, for example, it can be set to 40mm, 70mm or 100mm. In this way, the elongated third groove 2133 has a large length, a large opening area, smoother exhaust, high exhaust rate, and is less likely to explode.

[0126] Figure 11 A cross-sectional view of the housing 211 in an embodiment of this application is shown. Figure 11 The opening above corresponds to the housing 211. Figure 11 Below is the bottom wall of the housing 211, and a pressure relief area 213 is provided on the bottom wall of the housing 211; Figure 12 for Figure 11 An enlarged view of region A2, which includes pressure relief region 213, wherein... Figure 12 The upper part corresponds to the interior of the shell 211. Figure 12 The lower part corresponds to the outside of the housing 211. Specifically, as shown in... Figure 12 As shown, with Figure 9 Similarly, a first groove 2131 is provided on the inner surface of the housing 211, a second groove 2132 is provided on the outer surface of the housing 211, and a third groove 2133 is provided on the bottom wall of the second groove 2132. Figure 9 The difference is, Figure 12 The cross-sectional shape of the first groove 2131, the second groove 2132 and the third groove 2133 shown is no longer a ring shape with a protruding structure in the middle.

[0127] Regarding the first groove 2131, the second groove 2132, and the third groove 2133 in the embodiments of this application, Figure 12 The shape of the cross section shown, Figure 12 Taking a rounded trapezoid as an example, other shapes can be used depending on the actual application. For example, the angle formed by the bottom wall and side wall of each groove can be a right angle, that is, the first groove 2131, the second groove 2132, and the third groove 2133 can be right-angled grooves; or, considering that the bottom walls of the first groove 2131, the second groove 2132, and the third groove 2133 are all elongated, it is difficult to process them into right angles during the manufacturing process, so the first groove 2131, the second groove 2132, and the third groove 2133 can also be... Figure 12 As shown, the groove has an inclined angle, making its overall shape trapezoidal, for example... Figure 12 The rounded trapezoidal shape means that the area of ​​the bottom wall of the first groove 2131, the second groove 2132 and the third groove 2133 is smaller than the area of ​​the opening, but the embodiments of this application are not limited to this.

[0128] like Figure 12 As shown, with Figure 9 Similarly, for the exterior of the housing 211, a protrusion 2137 may also be present on the outer surface of the housing 211 surrounding the second groove 2132, the protrusion 2137 extending away from the interior of the housing 211 relative to the outer surface of the housing 211. For the sake of simplicity, it will not be described in detail here.

[0129] like Figure 12 As shown, in order to protect the side of the pressure relief area 213 away from the housing 211 from the influence of other components outside the battery box 21, similar to the first embodiment, the pressure relief area 213 may also include: a protective sheet 2135 for protecting the pressure relief area 213, which is disposed on the outer surface of the battery box 21 and covers the second groove 2132.

[0130] It should be understood that the dimensions of each part in the embodiments of this application can be set according to actual applications. For example, the following is combined with Figure 12 Let's illustrate with examples.

[0131] Regarding the size of the pressure relief area 213, the area of ​​the bottom wall of the second groove 2132 is usually set to be equal to the area of ​​the bottom wall of the first groove. For example, the area of ​​the bottom wall of the first groove can usually be set to 150 mm². 2 Up to 330mm 2 For example, it can be set to 150mm 2 200mm 2 Or 330mm 2 The area of ​​the bottom wall of the second groove 2132 can also typically be set to 150mm². 2 Up to 330mm 2 For example, it can be set to 150mm 2 200mm 2 Or 330mm 2 Additionally, the width of the bottom wall of the first groove 2131 can also be equal to the width of the bottom wall of the second groove 2132, for example, as... Figure 12 As shown, the width L2 of the bottom wall of the first groove 2131 is equal to the width L2 of the bottom wall of the second groove 2132, and can be set to 3mm to 6mm, for example, it can be set to 3mm, 5mm or 6mm.

[0132] like Figure 12As shown, taking the pressure relief area 213 located on the bottom wall of the housing 211 as an example, the thickness h11 of the bottom wall of the housing 211 can typically be set to 1.2mm to 2mm, for example, it can be set to 1.2mm, 1.5mm or 2mm; the depth h12 of the first groove 2131 relative to the inner surface of the battery box 21 can typically be set to 0.4mm to 0.7mm, for example, it can be set to 0.4mm, 0.5mm or 0.7mm; the depth h13 of the second groove 2132 relative to the outer surface of the battery box 21 is 0.3mm to 0.6mm, for example, it can be set to 0.3mm, 0.5mm or 0.6mm; the thickness h14 of the pressure relief area 213 at the third groove 2133 can typically be set to 0.16mm to 0.25mm, for example, it can be set to 0.16mm, 0.2mm or 0.25mm.

[0133] Referring to the relevant dimensions of the first groove 2131 and the second groove 2132 mentioned above, such as depth and bottom wall area, etc., Figure 12 As shown, the height h15 of the protrusion 2137 relative to the outer surface of the battery box 21 can typically be set to 0.25mm to 0.5mm, for example, it can be set to 0.25mm, 0.3mm or 0.5mm; the thickness h16 of the protective sheet 2135 can typically be set to 0.1mm to 0.2mm, for example, it can be set to 0.1mm, 0.15mm or 0.2mm.

[0134] The above text combines Figures 1 to 12 The battery box, battery cell, and battery of embodiments of this application are described below. Figure 13 and Figure 14 This application describes a method and apparatus for preparing a battery box according to embodiments of the present application.

[0135] Specifically, Figure 13 A schematic flowchart of a method 200 for preparing a battery box according to an embodiment of this application is shown. Figure 13 As shown, the method 200 may include: S210, providing a first groove on the inner surface of the battery box and a second groove on the outer surface of the battery box to form a pressure relief area of ​​the battery box, wherein the first groove and the second groove are disposed opposite to each other; S220, providing a third groove on the bottom wall of the first groove and / or the bottom wall of the second groove, wherein the pressure relief area is configured to rupture at the third groove to release the internal pressure when the internal pressure of the battery box reaches a threshold.

[0136] Optionally, as one embodiment, the outer surface of the battery box has a protrusion surrounding the second groove.

[0137] Optionally, as an embodiment, the bottom wall of the first groove and / or the bottom wall of the third groove are elongated.

[0138] Optionally, as an embodiment, the first groove and / or the second groove are annular grooves.

[0139] It should be understood that the method 200 of this application embodiment can be used to prepare the battery box 21 of this application embodiment, and for the sake of brevity, it will not be described in detail here.

[0140] It should be understood that in the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0141] Figure 14 A schematic block diagram of an apparatus 300 for manufacturing a battery case according to an embodiment of this application is shown. Figure 14 As shown, the device 300 according to an embodiment of this application includes: a setting module 310, the setting module 310 being configured to: set a first groove on the inner surface of the battery box and set a second groove on the outer surface of the battery box to form a pressure relief area of ​​the battery box, wherein the first groove and the second groove are disposed opposite to each other; and set a third groove on the bottom wall of the first groove and / or the bottom wall of the second groove, the pressure relief area being configured to rupture at the third groove to release the internal pressure when the internal pressure of the battery box reaches a threshold.

[0142] Optionally, as one embodiment, the outer surface of the battery box has a protrusion surrounding the second groove.

[0143] Optionally, as an embodiment, the bottom wall of the first groove and / or the bottom wall of the third groove are elongated.

[0144] Optionally, as an embodiment, the first groove and / or the second groove are annular grooves.

[0145] It should be understood that the apparatus 300 according to the embodiments of this application may correspond to performing the method 200 in the embodiments of this application, and the above and other operations and / or functions of each unit in the apparatus 300 are respectively for implementing Figure 13 The corresponding process of method 200 in the document will not be elaborated here for the sake of brevity.

[0146] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended 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 they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features. However, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A battery cell, characterized in that, include: Electrode assembly (22); The housing (211) is a hollow cuboid with an opening at one end. The housing is used to accommodate the electrode assembly (22). The bottom wall of the housing (211) is provided with a pressure relief area (213). The pressure relief area (213) includes a first groove (2131) provided on the inner surface of the housing (211) and a second groove (2132) provided on the outer surface of the housing (211). The first groove (2131) and the second groove (2132) are arranged opposite to each other. The bottom wall of the first groove (2131) and / or the bottom wall of the second groove (2132) are provided with a third groove (2133). The pressure relief area (213) is configured to rupture at the third groove (2133) to release the internal pressure when the internal pressure of the battery cell reaches a threshold. A pad (24) is located between the electrode assembly (22) and the bottom wall of the housing (211). The pad (24) has a through hole corresponding to the pressure relief area (213) so that the pad (24) does not block the pressure relief area (213). A cover plate (212) covers the opening of the housing (211); The first groove (2131) and / or the second groove (2132) are annular grooves; The bottom wall of the second groove (2132) is provided with an annular fourth groove (2134), and the third groove (2133) is provided on the bottom wall of the fourth groove (2134).

2. The battery cell according to claim 1, characterized in that, The third groove (2133) is disposed on the bottom wall of the second groove (2132).

3. The battery cell according to claim 1, characterized in that, The thickness of the pressure relief area (213) at the third groove (2133) is 0.16 mm to 0.25 mm.

4. The battery cell according to claim 1, characterized in that, The axis perpendicular to the bottom wall of the first groove (2131) is the same as the axis perpendicular to the bottom wall of the second groove (2132).

5. The battery cell according to claim 1, characterized in that, The outer surface of the housing (211) has a protrusion (2137) surrounding the second groove (2132).

6. The battery cell according to claim 5, characterized in that, The protrusion (2137) protrudes from the outer surface of the housing (211) by a height of 0.25 mm to 1 mm.

7. The battery cell according to claim 1, characterized in that, The bottom wall of the first groove (2131) and / or the bottom wall of the second groove (2132) are elongated.

8. The battery cell according to claim 7, characterized in that, The width of the bottom wall of the first groove (2131) and / or the width of the bottom wall of the second groove (2132) is 3mm to 6mm.

9. The battery cell according to claim 7, characterized in that, The bottom wall area of ​​the first groove (2131) is 150 mm². 2 Up to 330mm 2 ; and / or, the area of ​​the bottom wall of the second groove (2132) is 150 mm². 2 Up to 330mm 2 .

10. The battery cell according to claim 7, characterized in that, The first groove (2131) has a depth of 0.4 mm to 0.7 mm relative to the inner surface of the housing (211); and / or, the second groove (2132) has a depth of 0.3 mm to 0.6 mm relative to the outer surface of the housing (211).

11. The battery cell according to claim 7, characterized in that, The bottom wall of the third groove (2133) is elongated.

12. The battery cell according to claim 11, characterized in that, The length of the third groove (2133) is 40mm to 100mm.

13. The battery cell according to claim 1, characterized in that, The bottom wall area of ​​the first groove (2131) is 400 mm². 2 Up to 1000mm 2 ; and / or, the area of ​​the bottom wall of the second groove (2132) is 600 mm². 2 Up to 1200mm 2 .

14. The battery cell according to claim 1, characterized in that, The first groove (2131) has a depth of 1 mm to 2 mm relative to the inner surface of the housing (211); and / or, the second groove (2132) has a depth of 0.3 mm to 0.6 mm relative to the outer surface of the housing (211).

15. The battery cell according to claim 1, characterized in that, The bottom wall area of ​​the fourth groove (2134) is 200 mm². 2 Up to 800mm 2 .

16. The battery cell according to any one of claims 1 to 15, characterized in that, The battery cell also includes: A protective plate (2135) for protecting the pressure relief area is disposed on the outer surface of the housing (211) and covers the second groove (2132).

17. A battery, characterized in that, include: A plurality of battery cells, wherein the plurality of battery cells includes at least one battery cell as described in any one of claims 1 to 16; A busbar component is used to realize the electrical connection of the multiple battery cells; The housing is used to house the plurality of battery cells and the busbar component.

18. An electrical appliance, characterized in that, include: The battery as claimed in claim 17.

19. A method for preparing a battery cell, characterized in that, include: An electrode assembly is disposed inside a housing, which is a hollow cuboid with an opening at one end; A first groove is provided on the inner surface of the bottom wall of the housing, and a second groove is provided on the outer surface of the bottom wall of the housing to form a pressure relief area of ​​the housing, wherein the first groove and the second groove are arranged opposite to each other; A third groove is provided on the bottom wall of the first groove and / or the bottom wall of the second groove, and the pressure relief area is configured to rupture at the third groove to release the internal pressure when the internal pressure of the battery cell reaches a threshold. A pad is provided between the electrode assembly and the bottom wall of the housing; A through hole corresponding to the pressure relief area is provided on the pad so that the pad does not block the pressure relief area; Cover the opening of the housing with the cover plate; Wherein, the first groove (2131) and / or the second groove (2132) are annular grooves; The bottom wall of the second groove (2132) is provided with an annular fourth groove (2134), and the third groove (2133) is provided on the bottom wall of the fourth groove (2134).

20. An apparatus for preparing battery cells, characterized in that, include: The settings module is used for: An electrode assembly is disposed inside a housing, which is a hollow cuboid with an opening at one end; A first groove is provided on the inner surface of the bottom wall of the housing, and a second groove is provided on the outer surface of the bottom wall of the housing to form a pressure relief area of ​​the housing, wherein the first groove and the second groove are arranged opposite to each other; A third groove is provided on the bottom wall of the first groove and / or the bottom wall of the second groove, and the pressure relief area is configured to rupture at the third groove to release the internal pressure when the internal pressure of the battery cell reaches a threshold. A pad is provided between the electrode assembly and the bottom wall of the housing; A through hole corresponding to the pressure relief area is provided on the pad so that the pad does not block the pressure relief area; Cover the opening of the housing with the cover plate; Wherein, the first groove (2131) and / or the second groove (2132) are annular grooves; The bottom wall of the second groove (2132) is provided with an annular fourth groove (2134), and the third groove (2133) is provided on the bottom wall of the fourth groove (2134).

Images