RU2813836C1 - Pressure release mechanism, battery box, battery cell, method and apparatus for manufacturing - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to a pressure release mechanism, a battery box, a battery cell, a battery, a method and an apparatus for making, which can improve the operating characteristics of the pressure release mechanism on the lithium-ion battery. Increased safety of lithium-ion batteries is a technical result, which is achieved by the fact that the pressure release mechanism for the battery box comprises connecting mechanism (2131), which is made with opening (2131a) and first bulge (2131b), which is connected to inner wall of opening (2131a) and extends to axis of opening (2131a), pressure release sheet (2132), configured to be actuated to reduce the internal pressure of the battery box when the internal pressure reaches a threshold value, wherein the pressure relief sheet (2132) is located on one side of first bulge (2131b), as well as the first protective sheet (2133), configured to protect the pressure release sheet (2132) and located on the other side of first bulge (2131b) away from the pressure release sheet (2132), compression ring (2134), made with possibility of pressing first protective sheet (2133) and located on side of first protective sheet (2133) away from first bulge (2131b), and clamping structure (2135) connected to connecting mechanism (2131) and capable of pressing to axis of opening (2131a) in order to press compression ring (2134).

EFFECT: said pressure release mechanism design provides convenience of battery assembly, and arrangement of the mechanism on the side wall of the battery box with a smaller area contributes to the arrangement of a plurality of battery cells and can further increase the energy density of the battery.

45 cl, 24 dwg

Description

[01] This application relates to the field of energy storage components, and in particular to a pressure relief mechanism, battery box, battery cell, battery, manufacturing method and apparatus.

BACKGROUND OF THE INVENTION

[02] Li-ion batteries have the advantages of small size, high energy density, long charge/discharge cycle life and long shelf life, etc., and are widely used in some electronic devices, electric vehicles, electronic toys and other fields, such as in mobile phones, laptops, electric bicycles, electric cars, electric airplanes, electric ships, electronic toy cars, electronic toy ships, electronic toy planes, electric tools and the like.

[03] With the continuous development of lithium-ion battery technology, the safety performance of lithium-ion batteries has become increasingly demanding. The pressure relief mechanism on a lithium-ion battery has an important impact on the safety performance of a lithium-ion battery. For example, when short circuit, overcharge, etc. occur. lithium-ion battery, this may cause internal thermal runaway of the lithium-ion battery and in turn cause the internal air pressure to rise sharply, at which time the pressure relief mechanism must be activated to reduce the internal air pressure to the outside to prevent the lithium-ion battery from exploding. Therefore, the design of the pressure relief mechanism is extremely important.

SUMMARY OF THE INVENTION

[04] This application provides a pressure relief mechanism, a battery box, a battery cell, a battery, a method and an apparatus for manufacturing for improving the performance of a pressure relief mechanism on a battery.

[05] According to a first aspect of the present application, there is provided a pressure relief mechanism for a battery box, comprising: a connecting mechanism comprising an opening and a first boss, the first boss being connected to an inner wall of the opening and extending to an axis of the opening; a pressure relief sheet operable to reduce the internal pressure of the battery box when the internal pressure reaches a threshold value, the pressure relief sheet being located on one side of the first bulge; a first protective sheet configured to protect the pressure relief sheet and located on the other side of the first boss away from the pressure relief sheet; a compression ring configured to press the first protective sheet and located on a side of the first protective sheet away from the first thickening; and a pressing structure connected to the connecting mechanism and capable of being pressed against the axis of the opening to press the compression ring.

[06] In the pressure relief mechanism according to embodiments of the present application, the protective sheet is located on the side of the pressure relief sheet that is closer to the inside of the battery box, so that when the pressure relief sheet is used with the battery box, it can prevent the pressure relief sheet from directly contacting the solution electrolyte in the battery box, thereby reducing the corrosion of the pressure relief sheet caused by the electrolyte solution, and also reducing the effect of the electrolyte solution on the pressure relief sheet. In addition, in the installation process, by providing a bulge on the inner wall of the opening of the connecting mechanism and placing a protective sheet and a pressure relief sheet on both sides of the bulge, respectively, the pressure relief mechanism can be installed on both sides at the same time to simplify the installation process. On the side where the protective sheet is installed, the protective sheet can be pressed by the compression ring, and then the compression ring is pressed by the pressing structure. The overall design is simple and easy to operate.

[07] In some embodiments, the clamping structure includes at least one projection structure, and the at least one projection structure is located on a side surface of the coupling mechanism proximate the compression ring and protrudes in a direction away from the compression ring.

[08] The clamp structure in embodiments of the present application may be located around the edge of the opening.

[09] In some embodiments, the at least one projection structure is a plurality of projection structures spaced apart from each other.

[010] By being arranged in a plurality of spaced protruding structures, the structure is simpler and easier to press.

[011] In some embodiments, the height to which the protruding structure projects relative to the side surface of the coupling mechanism in the vicinity of the compression ring is between 0.3 mm and 0.5 mm.

[012] The size of the protruding structure can be flexibly set according to actual applications, such as according to the size of the compression ring.

[013] In some embodiments, the clamping structure, once pressed, extends toward the axis of the opening relative to the inner wall of the opening.

[014] The pressing structure is located at the edge of the opening, and the pressing structure, after being pressed, extends in the axial direction of the opening to press the compression ring.

[015] In some embodiments, the clamping structure, once pressed, extends toward the axis of the opening at a distance of 0.8 mm to 1 mm relative to the inner wall of the opening.

[016] In some embodiments, the thickness of the connecting mechanism along the axial direction of the opening is from 4 mm to 5 mm.

[017] In some embodiments, the thickness of the first thickening is from 1.25 mm to 1.45 mm.

[018] In some embodiments, the thickness of the pressure relief sheet is between 0.3 mm and 1 mm.

[019] In some embodiments, the thickness of the first protective sheet is from 0.3 mm to 0.5 mm.

[020] In some embodiments, the thickness of the compression ring is between 1 mm and 1.2 mm.

[021] The size of each component of the pressure relief mechanism can be flexibly set according to actual applications.

[022] In some embodiments, the coupling mechanism further comprises a second boss, the second boss being coupled to an outer wall of the coupling mechanism and extending away from the axis of the opening, and the second boss being configured to accommodate a pressure relief mechanism on the battery box.

[023] In order to install the pressure relief mechanism on the battery box, a second boss may be provided on the outside of the connecting mechanism related to the pressure relief mechanism. The pressure release mechanism is fixed by a second thickening, which is convenient for installation. For example, when the pressure relief mechanism is installed on the bottom wall of the battery box body, considering that the body is hollow and the depth is affected, it is more convenient to fix and install with the second thickening.

[024] In some embodiments, the second boss is located at the end of the connecting mechanism near the clamping structure.

[025] The side of the pressure relief mechanism near the clamping structure is located inside the battery box, and the second boss is located at the end near the clamping structure, so that the end of the pressure relief mechanism near the clamping structure can be substantially flush with the inner surface of the battery box, while the other the end of the pressure relief mechanism may protrude from the outer surface of the battery box so as not to affect the installation of battery box components such as the internal electrode assembly.

[026] In some embodiments, the thickness of the second thickening is from 0.6 mm to 0.9 mm.

[027] In some embodiments, a side surface of the pressure relief sheet away from the first protective sheet and/or a side surface of the pressure relief sheet proximal to the first protective sheet is provided with a first recess, a bottom wall of the first recess is provided with a second recess, and the pressure relief sheet is configured to cracking on the second recess to reduce the internal pressure of the battery box when the internal pressure reaches a threshold value.

[028] To facilitate cracking of the pressure relief sheet when thermal runaway occurs inside the battery cell, the surface of the pressure relief sheet may be further provided with a recess, that is, the surface of the pressure relief sheet is provided with a recess area, and the thickness of the recess is smaller, so that the pressure relief mechanism can crack in the recess to achieve more precise directional cracking and release. In addition, considering the ease of installation, the connection between the pressure relief sheet and the connecting mechanism does not need to be made too thin. Therefore, the first recess can be provided in the pressure relief sheet, and the second recess can be provided in the first recess, so that the position outside the recess area can be thicker, and the thickness within the second recess can be smaller, which is more convenient for processing.

[029] In some embodiments, the first recess is located on a side surface of the pressure relief sheet away from the first protective sheet.

[030] Given that the side of the pressure relief sheet near the first protective sheet faces the inside of the battery box during installation, if a recess is provided on that side, since there is electrolyte solution in the battery box, if the sealing of the first protective sheet is not good enough, electrolyte solution may accumulate in the recess and corrode the recessed part, and thus may cause premature cracking of the pressure relief mechanism. Therefore, a recess is generally provided on the side of the pressure relief sheet away from the first protective sheet, which can retard corrosion caused by the electrolyte solution.

[031] In some embodiments, the thickness of the pressure relief sheet on the second recess is from 0.08 mm to 0.15 mm.

[032] In some embodiments, the depth of the first recess is 0.3 mm.

[033] The thickness of each recess on the pressure relief sheet can be set according to the thickness of the pressure relief sheet.

[034] In some embodiments, the pressure relief mechanism further comprises: a second protective sheet configured to protect the pressure relief sheet, the second protective sheet mounted on the connecting mechanism, located on a side of the pressure relief sheet away from the first boss and covering the pressure relief sheet.

[035] A second protective sheet provided on a side of the pressure relief sheet away from the inside of the battery box can protect the pressure relief sheet from being affected by external components.

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

[037] In some embodiments, a gap is provided between the surface of the second protective sheet in the direction towards the pressure relief sheet and the surface of the pressure relief sheet in the direction towards the second protective sheet.

[038] Since the pressure relief sheet needs space to open when released, it is necessary to provide a gap between the second protective sheet and the pressure relief sheet. This gap is used to open the pressure relief sheet, and can also prevent wear of the pressure relief sheet when the second protective sheet is attached to the pressure relief sheet, thereby further protecting the pressure relief sheet.

[039] In some embodiments, the gap is greater than or equal to 0.5 mm.

[040] The size of the gap between the second protective sheet and the pressure relief sheet can be set according to actual applications.

[041] In some embodiments, the pressure relief mechanism further comprises: an annular spacer located between the first protective sheet and the first boss.

[042] By adding an annular spacer between the first protective sheet and the first thickening, wear of the first protective sheet can be reduced, which is also more advantageous for sealing the first protective film to the pressure relief sheet, which further reduces the likelihood of the electrolyte solution contacting the pressure relief sheet.

[043] In some embodiments, the thickness of the ring gasket is between 0.2 mm and 0.4 mm.

[044] The size of the ring gasket can be set according to actual applications.

[045] According to a second aspect of the present application, there is provided a battery box comprising: a housing, wherein a first wall of the housing is provided with a through hole; and a pressure relief mechanism as described in the first aspect and any possible implementations of the first aspect, wherein the pressure relief mechanism is located on the first wall by a connecting mechanism and is positioned in accordance with the through hole for actuation to reduce the internal pressure of the battery box when the internal pressure reaches the threshold value.

[046] In some embodiments, the pressure structure is located closer to the interior of the housing than the pressure relief sheet.

[047] The first protective sheet of the pressure relief mechanism is located closer to the inside of the battery box, so that the first protective sheet can protect the pressure relief sheet, reduce corrosion of the pressure relief sheet caused by the electrolyte solution in the battery box, and also reduce the influence of the electrolyte solution on the relief sheet pressure, which causes damage to the pressure relief sheet due to vibration and shock and, in turn, leads to premature failure of the pressure relief sheet.

[048] In some embodiments, a third recess is provided on a side surface of the first wall near the interior of the housing, and a through hole is provided on the bottom wall of the third recess; and the connecting mechanism further comprises a second boss, wherein the second boss is connected to an outer wall of the connecting mechanism and extends from the axis of the opening, wherein the second boss is located at the end of the connecting mechanism near the clamping structure and the second boss is mounted on the lower wall of the third recess, so that the pressure release mechanism is is at least partially located in the through hole.

[049] A recess is provided on the inner wall of the battery box body such that a second pressure relief mechanism boss is mounted on the bottom wall of the recess to realize locking of the pressure relief mechanism, thereby ensuring that the surface of the pressure relief mechanism inside the battery box is substantially flush with the inner surface of the battery box so as not to affect the installation of components such as the electrode assembly inside the battery box.

[050] In some embodiments, the body is a hollow cuboid and includes an opening at the end.

[051] In some embodiments, the first wall is a bottom wall of the housing and the bottom wall of the housing is a wall opposite the opening of the housing.

[052] Given that the electrode clamps are generally located on the cover plate, if the pressure relief mechanism is also located on the cover plate, when thermal runaway occurs inside the battery cell, the pressure release mechanism cracks and the liquid or solid combustible material, which may also contain conductive material , is released when the internal gas pressure in the battery cell is released, resulting in a short circuit between the electrode terminals. Moreover, given that the electrode clamps usually face upward, that is, towards the passenger side when the battery is installed in the vehicle, if the pressure relief mechanism is installed on the same side as the electrode clamps, gas flow and other materials are released after the mechanism cracks pressure release will be ejected upward, which may cause burns or scalding to the occupant, increasing the risk to the occupant. Therefore, in the embodiments of the present application, the pressure relief mechanism is located on the bottom wall of the housing, and the pressure relief mechanism discharges downwards, which can solve the above-mentioned problems to some extent.

[053] In some embodiments, the thickness of the bottom wall of the housing is between 1.5 mm and 2.5 mm.

[054] In some embodiments, the battery box includes a cover plate covering and covering the opening of the housing.

[055] In some embodiments, the battery box further includes electrode clamps, the electrode clamps including a positive electrode clamp and a negative electrode clamp, both of which are located on the cover plate.

[056] According to the third aspect of the present application, there is provided a battery cell comprising: a battery box as described in the second aspect and any possible implementations of the second aspect; and an electrode assembly, the electrode assembly being located in the battery box.

[057] In some embodiments, the body is a hollow cuboid and includes an opening at the end.

[058] In some embodiments, the battery cell further includes a support plate, wherein the support plate is located between the electrode assembly and a bottom wall of the housing, and the bottom wall of the housing is a housing wall located opposite the housing opening.

[059] In some embodiments, the first wall is a bottom wall of the housing, and the support plate is provided with a bypass zone corresponding to the pressure relief mechanism such that the support plate does not block the pressure relief mechanism.

[060] When the pressure relief mechanism is located on the bottom wall, since the bottom wall is also provided with a support plate, when thermal runaway occurs inside the battery cell, the support plate can prevent gas from escaping through the pressure relief mechanism. Therefore, in order to facilitate cracking of the pressure relief mechanism, part of the support plate area can be removed to form a bypass area, that is, a through hole is provided on the support plate at the location of the pressure relief mechanism, so that the support plate does not block the pressure relief mechanism.

[061] According to a fourth aspect of the present application, there is provided a battery comprising: a plurality of battery cells, the plurality of battery cells including at least one battery cell as described in the third aspect and any possible implementations of the third aspect; a bus component configured to provide an electrical connection between a plurality of battery cells; and a housing configured to receive a plurality of battery cells and a busbar component.

[062] According to the fifth aspect of the present application, a power consuming device including a battery as described in the fourth aspect is provided.

[063] The power consuming device may be a vehicle, a ship, or a spacecraft.

[064] According to a sixth aspect of the present application, there is provided a method for manufacturing a pressure relief mechanism for a battery box, the method comprising: providing a connecting mechanism, wherein the connecting mechanism includes an opening and a first boss, the first boss being connected to an inner wall of the opening and extending to an axis of the opening; providing a pressure relief sheet operable to reduce the internal pressure of the battery box when the internal pressure reaches a threshold value, the pressure relief sheet being located on one side of the first boss; providing a first protective sheet configured to protect the pressure relief sheet and located on the other side of the first bulge away from the pressure relief sheet; providing a compression ring configured to compress the first protective sheet and located on a side of the first protective sheet away from the first thickening; and providing a pressing structure connected to the connecting mechanism and capable of pressing against the axis of the opening to press the compression ring.

[065] In some embodiments, the clamping structure includes at least one projection structure, and the at least one projection structure is located on a side surface of the coupling mechanism proximate the compression ring and protrudes in a direction away from the compression ring.

[066] In some embodiments, the clamping structure, once pressed, extends toward the axis of the opening relative to the inner wall of the opening.

[067] In some embodiments, the coupling mechanism further comprises a second boss, the second boss being coupled to an outer wall of the coupling mechanism and extending away from the axis of the opening, and the second boss being configured to accommodate a pressure relief mechanism on the battery box.

[068] It should be understood that the method of manufacturing the pressure relief mechanism in embodiments of the present application can be used to manufacture the pressure relief mechanism in the first aspect and in any possible implementations of the first aspect.

[069] According to a seventh aspect of the present application, there is provided an apparatus for producing a pressure relief mechanism for a battery box, the apparatus comprising a providing module configured to: provide a connecting mechanism, wherein the connecting mechanism includes an opening and a first boss, the first boss is connected to an inner wall of the opening and passes to the axis of the opening; providing a pressure relief sheet operable to reduce the internal pressure of the battery box when the internal pressure reaches a threshold value, the pressure relief sheet being located on one side of the first boss; providing a first protective sheet configured to protect the pressure relief sheet and located on the other side of the first boss away from the pressure relief sheet; providing a compression ring configured to compress the first protective sheet and located on a side of the first protective sheet away from the first thickening; and providing a pressing structure coupled to the connecting mechanism and capable of pressing against the axis of the opening to press the compression ring.

[070] In some embodiments, the clamp structure includes at least one projection structure, and the at least one projection structure is located on a side surface of the coupling mechanism proximate the compression ring and protrudes in a direction away from the compression ring.

[071] In some embodiments, the clamping structure, once pressed, extends toward the axis of the opening relative to the inner wall of the opening.

[072] In some embodiments, the coupling mechanism further comprises a second boss, the second boss being coupled to an outer wall of the coupling mechanism and extending away from the axis of the opening, and the second boss being configured to accommodate a pressure relief mechanism on the battery box.

[073] It should be understood that the pressure relief mechanism manufacturing apparatus of the embodiments of the present application may be used to carry out the method of the sixth aspect and any possible implementations of the sixth aspect. In particular, the apparatus includes a unit for performing the method in the sixth aspect or in any possible implementations of the sixth aspect.

BRIEF DESCRIPTION OF GRAPHIC MATERIALS

[074] The accompanying drawings described herein are used to provide further understanding of this application and constitute a part of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute undue limitation of this application. On graphic materials:

in fig. 1 is a schematic outline view of some embodiments of a vehicle in which a battery of the present application is used;

in fig. 2 is a schematic structural representation of some embodiments of a battery according to the present application;

in fig. 3 is a schematic structural representation of some embodiments of a battery module in a battery according to the present application;

in fig. 4 is an exploded view of some embodiments of a battery cell according to the present application;

in fig. 5 is an exploded view of some embodiments of a battery box with a pressure relief mechanism according to the present application;

in fig. 6 is an exploded view of other embodiments of a battery box with a pressure relief mechanism according to the present application;

in fig. 7 is a top view of a battery cell according to the present application;

in fig. 8 is a cross-sectional view taken in the direction AA' of FIG. 9;

in fig. 9 is a schematic representation of some embodiments of a support plate according to the present application;

in fig. 10-13 are exploded views of some embodiments of the pressure relief mechanism of the present application;

in fig. 14 is a top view of some embodiments of the pressure relief mechanism of the present application;

in fig. 15 is a cross-sectional view of some embodiments of the pressure relief mechanism of the present application along the direction B-B';

in fig. 16 is a schematic diagram of the coupling mechanism shown in FIG. 15;

in fig. 17 is an enlarged view of the area A1 shown in FIG. 15;

in fig. 18 is a schematic view of the pressure relief sheet shown in FIG. 15;

in fig. 19 is a cross-sectional view of other embodiments of the pressure relief mechanism of the present application along the direction B-B';

in fig. 20 is a top view of other embodiments of the pressure relief mechanism of the present application;

in fig. 21 is a cross-sectional view taken in the direction C-C' of FIG. 20;

in fig. 22 is an enlarged view of area A2 shown in FIG. 21;

in fig. 23 is a flow diagram of some embodiments of a method for manufacturing a pressure relief mechanism according to the present application; And

in fig. 24 is a schematic structural representation of some embodiments of an apparatus for manufacturing a pressure relief mechanism according to the present application.

DESCRIPTION OF IMPLEMENTATION OPTIONS

[075] To make the objectives, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and fully described below with reference to the accompanying drawings in the embodiments of the present application. It will be appreciated that the described embodiments represent some, and not all, embodiments of the present application. All other embodiments obtained without creative effort by one skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[076] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used in the description herein are solely for the purpose of describing specific embodiments and are not intended to limit this application. The words “comprise” and “having” and any variations thereof in the specification and claims of this application and in the foregoing description of the accompanying drawings are intended to cover non-exclusive inclusions. The terms “first”, “second”, etc. in the description and claims of this application, as well as in the above graphics, are used to distinguish different objects and not to describe a specific order or primary-minor relationship.

[077] The expression “embodiments” as used herein means that the particular features, structures, or characteristics described in combination with the embodiments may be included in at least one embodiment of the present application. This expression in different places in the description does not necessarily refer to the same embodiment or to an independent or alternative embodiment to the exclusion of another embodiment. Those skilled in the art will appreciate, both explicitly and implicitly, that the embodiment described herein may be combined with another embodiment.

[078] The term “and/or” as used herein is merely a relational relation describing related objects, which indicates the possible existence of three relations. For example, A and/or B may indicate the following three situations: only A exists; there is both A and B; and only B exists. In addition, the "/" symbol in this text generally indicates that the related objects before and after this symbol are in an "or" relationship.

[079] As used herein, "multiple" means two or more (including two). Similarly, “multiple groups” means two groups or more (including two groups), and “multiple sheets” means two sheets or more (including two sheets).

[080] The pressure release mechanism, battery cell, and battery comprising a plurality of battery cells described in the embodiments of the present application are all applicable to various devices using a battery, such as mobile phones, portable devices, laptops, electric vehicles, electric vehicles, ships , spacecraft, electronic toys, power tools and the like. For example, spacecraft include airplanes, rockets, space shuttles, spaceships and the like; electronic toys include fixed or movable electronic toys such as game consoles, electric toy cars, electric toy ships, electric toy airplanes, and the like; and electric tools include electric metal cutting tools, electric abrasive tools, electric assembly tools and electric railway tools such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, electric impact drills, concrete vibrators and electric planes.

[081] The pressure relief mechanism, battery cell, and battery containing a plurality of battery cells described in the embodiments of the present application are not only applicable to the devices described above, but are applicable to all devices using a battery, however, for the sake of brevity, all the following embodiments are described using the example of an electric vehicle.

[082] For example, as shown in FIG. 1, which is a schematic structural view of a vehicle 1 according to one embodiment of the present application, the vehicle 1 may be a fuel-powered vehicle, a gas-powered vehicle, or a , operating on a new type of energy. The new energy vehicle may be a battery electric vehicle, a hybrid vehicle, an extended range vehicle, etc. The battery 10 may be located within the vehicle 1. The battery 10 may be a battery pack or a battery module. For example, the battery 10 may be located at the bottom, or the front, or the rear of the vehicle 1. The controller 30 and the motor 40 may also be located inside the vehicle 1. The battery 10 may be used to supply power to the vehicle 1. For example, , the battery 10 may serve as an operating power supply of the vehicle 1 and be used for an electrical circuit of the vehicle 1, for example, to meet the operating power requirements of the vehicle 1 during starting, navigation, and operation. In another embodiment of the present application, battery 10 may be used not only as an operating power source for the vehicle 1, but also as a source of driving power for the vehicle 1 to provide driving power for the vehicle 1 in place of, or partially in place of, fuel or natural gas.

[083] To meet different power needs, battery 10 may include one or more battery modules (or they may also be called battery packs), and multiple battery modules may be connected in series, or in parallel, or in series-parallel, which is a combination serial connection and parallel connection. For example, as shown in FIG. 2, which is a schematic structural view of a battery 10 according to another embodiment of the present application, the battery 10 includes a first cap 111, a second cap 112, and a plurality of battery modules 11, the shapes of the first cap 111 and the second cap 112 may be determined according to the shape of the combination of one or more battery modules 11. Both the first cover 111 and the second cover 112 contain an opening. For example, each of the first cover 111 and the second cover 112 may be a hollow cuboid and include only one surface as an opening surface, that is, the surface does not include a housing wall to provide communication between the interior and exterior of the housing. The first cap 111 and the second cap 112 are attached to each other at the openings to form a closed shell of the battery 10. One or more battery modules 11 are connected to each other in parallel, series or series-parallel and then placed in the shell formed after being attached to each other the first cover 111 and the second cover 112.

[084] In another embodiment of the present application, when the battery 10 includes one battery module 11, the battery module 11 is housed in a shell formed by attaching the first cover 111 and the second cover 112 to each other.

[085] Electrical power generated by one or more battery modules 11 is output through the shell through an electrically conductive mechanism (not shown).

[086] In addition, battery 10 may further comprise other structures that will not be described in detail herein. For example, battery 10 may further include a busbar component for providing electrical connection between a plurality of battery cells (not shown). As another example, battery 10 may further include a cooling component for holding a cooling medium to cool one or more battery packs 11, but embodiments of the present application are not limited to this.

[087] According to different power requirements, the battery module 11 may include one or more battery cells. For example, as shown in FIG. 3, a single battery module 11 may contain a plurality of battery cells 20, and a plurality of battery cells 20 may be connected in series, parallel, or parallel-series to achieve greater capacity or power. Moreover, any number of battery cells 20 may be installed in one battery module 11. Of this number, each battery cell 20 may include a secondary lithium ion battery, a primary lithium ion battery, a lithium sulfur battery, a lithium sodium an ion battery or a magnesium ion battery, but is not limited to them. The battery cell 20 may be in the shape of a cylinder, a flat body, or a cuboid, or other shapes.

[088] In another embodiment of the present application, a plurality of battery cells 20 may be stacked one above the other, and the plurality of battery cells 20 are connected in series, connected in parallel, or connected in parallel-series. In another embodiment of the present application, each battery cell 20 may be square, cylindrical, or other shapes.

[089] Each battery cell 20 may include a battery box and an electrode assembly disposed within the battery box, wherein the battery box may include two parts: a housing and a cover plate. The body can be a hollow cuboid, cube or cylinder. One of the surfaces of the housing contains an opening so that the electrode assembly can be placed in the housing; and the cover plate is connected to the housing at the housing opening to form a closed battery box of the battery cell 20, and the housing can be filled with an electrolyte solution.

[090] In addition, the battery box also includes two electrode clamps, which are typically located on the cover plate and connected to the electrode assembly. The pressure relief mechanism may also be located on the flat surface of the cover plate, and the pressure release mechanism may be part of the flat surface of the cover plate 212 or may be welded to the flat surface of the cover plate. In the normal state, the pressure release mechanism is sealed with the cover plate, that is, the cover plate is connected to the housing at the housing opening to form a battery box of the battery cell 20, and the space formed by the battery box is sealed. In the battery box, when the battery cell 20 produces too much gas, the expansion of the gas causes the air pressure in the battery box to rise above a preset value, the pressure relief mechanism may crack, allowing communication between the inside and outside of the battery box, and thus the gas released through a crack in the pressure release mechanism, thereby reducing the likelihood of an explosion.

[091] In the existing battery cell, the pressure relief mechanism is usually located on the cover plate and is on the same side as the electrode clamp, so that when thermal runaway occurs inside the battery cell, the pressure relief mechanism cracks, and the liquid or solid combustible material, which may also contain conductive material is expelled while the internal gas pressure in the battery cell is reduced, causing a short circuit between the electrode terminals. Moreover, given that the electrode clamps usually face upward, that is, towards the passenger side when the battery is installed in the vehicle, if the pressure relief mechanism is installed on the same side as the electrode clamps, gas flow and other materials are released after the mechanism cracks pressure release will be ejected upward, which may cause burns or scalding to the occupant, increasing the risk to the occupant. Therefore, in order to solve the above-mentioned problems, it is possible to provide that the pressure relief mechanism is installed in other places, for example installed on the housing below the cover plate, for example installed on the bottom wall of the housing.

[092] However, if the pressure relief mechanism is installed on the housing, since the housing is of a hollow structure with a hole at one end and the pressure relief mechanism is usually in the shape of a sheet, it may be inconvenient to install the pressure relief mechanism on the housing, especially if the pressure relief mechanism is installed on bottom wall of the housing. Due to the housing depth limitation, it is difficult to directly weld the sheet-shaped pressure relief mechanism to the bottom wall. In addition, the strength of the pressure relief mechanism must also be considered. For example, when a pressure relief mechanism is installed on the housing, the pressure of the internal electrode assembly on the pressure relief mechanism must be taken into account. For example, if the battery is installed in a vehicle, impacts will occur while the vehicle is moving, so that the electrode assembly will exert pressure on the side wall and bottom wall of the housing, and thus the pressure release mechanism must have sufficient strength. As another example, since there is an electrolyte solution in the housing, the corrosion of the pressure relief mechanism caused by the electrolyte solution also needs to be taken into account.

[093] Therefore, embodiments of the present application provide a pressure relief mechanism that can solve the above-mentioned installation and strength problems.

[094] In particular, also taking the embodiments shown in FIGS. 1 to 3 as examples, FIG. 4 shows another embodiment of a battery cell 20 of the embodiments of the present application. As shown in FIG. 4, battery cell 20 includes a battery box (not shown), one or more electrode assemblies 22, and a connecting member 23, wherein the battery box in embodiments of the present application includes a housing 211 and a cover plate 212.

[095] In particular, as shown in FIG. 4, the shape of the housing 211 included in the battery box of the battery cell 20 may be determined according to the shape of one or more electrode assemblies 22 after being combined, for example, the housing 211 may be a hollow cuboid , or a cube or a cylinder, and one of the surfaces of the body 211 contains an opening so that one or more electrode assemblies 22 can be placed in the body 211. For example, when the body 211 is a hollow cuboid or cube, one of the planes of the body 211 is surface with a hole, i.e. the plane does not include a housing wall to form communication between the inner and outer portions of the housing 211. When the housing 211 may be a hollow cylinder, the circular side surface of the housing 211 is an opening surface, that is, the circular side surface does not include a housing wall to provide communication between the inner and outer portions of the housing 211. The cover plate 212 is connected to the housing 211 at the opening of the housing 211 to form a closed battery box in which the battery cell 20 is housed, and an electrolyte solution is poured into the housing 211.

[096] As shown in FIG. 4, the battery box of the battery cell 20 may further include two electrode clamps 214, and the two electrode clamps 214 may be located on the cover plate 212. The cover plate 212 is generally in the shape of a flat plate, and the two electrode clamps 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 clamps 214 are a positive electrode clamp 214a and a negative electrode clamp 214b, respectively. Each electrode clamp 214 is suitably provided with a connecting member 23, or the connecting member may also be called a current collector member 23 or a copper-aluminum adapter plate 23, which is located between the cover plate 212 and the electrode assembly 22.

[097] As shown in FIG. 4, each electrode assembly 22 may specifically include at least one positive electrode terminal 221 and at least one negative electrode terminal 222. In addition, the electrode assembly 22 may also include a bare element and an insulating sheet wrapping the bare element, and the specific positions of the positive electrode terminal 221 and the negative electrode terminal 222 in FIG. 4 are not different. A positive electrode terminal 221 of one or more electrode assemblies 22 is connected to one electrode terminal via a connecting member 23. A negative electrode terminal 222 of one or more electrode assemblies 22 is connected to another electrode clamp via another connecting member 23. For example, a positive electrode terminal 214a is connected to a terminal 221 of the positive electrode via a connecting member 23, and the negative electrode terminal 214b is connected to the negative electrode terminal 222 via another connecting member 23.

[098] One or more electrode assemblies 22 may be provided in the battery cell 20 according to practical requirements. As shown in FIG. 4, the battery cell 20 is provided with at least two independent electrode assemblies 22.

[099] In this battery cell 20, the electrode assembly 22 may have a winding structure or may have a multi-layer structure, and embodiments of the present application are not limited to this.

[0100] In addition, as shown in FIG. 4, the battery cell 20 may also include a support plate 24. The support plate 24 is located between the electrode assembly 22 and the bottom wall of the housing 211, can support the electrode assembly 22, and can also effectively prevent interaction of the electrode assembly 22 with rounded corners around the bottom wall of the housing 211. The shape of the support plate 24 in embodiments of the present application may be provided in accordance with actual applications. For example, the support plate 24 may have a rectangular shape corresponding to the shape of the bottom wall of the housing 211, or, as shown in Fig. 4, may also have other shapes. In addition, the support plate 24 may be provided with one or more through holes, such as a plurality of through holes, uniformly or symmetrically spaced so as to provide communication between the spaces of the upper and lower surfaces of the support plate 24 and to allow gas generated in the electrolyte solution and the electrode assembly 22 , as well as the electrolyte solution could freely pass through the support plate 24 to facilitate the direction of liquid and gas.

[0101] The support plate 24 has a thickness typically of 0.3-5 mm and is preferably an insulating component, but may not be insulated. For example, the material of the support plate 24 may be PP, PE, PET, PPS, Teflon, stainless steel, aluminum and other materials that are resistant to electrolyte solutions and are insulating, while a plastic material such as PP, PE, PET or PPS may be a fire-resistant material, and the surface of a metal material such as aluminum or stainless steel may be anodized for insulation.

[0102] In addition, the battery cell 20 in embodiments of the present application may also include other components. For example, the battery cell 20 may also include a top plate, a sealing core, and a plastic core, and the top plate, a sealing core, and a plastic core may be mounted on the cover plate 212. In addition, the battery cell 20 may also include a blue film that is disposed on the outer surface of the battery case 211 to provide insulation and protection functions for the battery cell, but embodiments of the present application are not limited thereto.

[0103] In embodiments of the present application, as shown in FIG. 4, the battery box of the battery cell 20 further includes a pressure release mechanism 213, wherein the pressure release mechanism 213 is operable to reduce the internal pressure of the battery box 21 when the internal pressure reaches a threshold value. In the normal state, the pressure release mechanism 213 is part of the battery box 21 of the battery cell 20, and the space formed by the housing 211 and the cover plate 212 is sealed. However, when the battery cell 20 produces too much gas, the expansion of the gas causes the air pressure in the battery box 21 to rise above a preset value, the pressure release mechanism 213 may crack, providing communication between the inside and outside of the battery box 21, and thus the gas is released outward through a crack in the pressure release mechanism 213, thereby reducing the likelihood of an explosion.

[0104] The pressure relief mechanism 213 in embodiments of the present application may be located on the bottom wall of the housing 211, and the lower wall of the housing 211 is located opposite the opening of the housing 211. For example, the lower wall of the housing 211 may be provided with a through hole, and the pressure relief mechanism 213 is located at through hole. However, in addition to installing the pressure relief mechanism 213 on the bottom wall of the housing 211, as shown in FIG. 4, the pressure relief mechanism 213 can also be installed on any side wall of the housing 211. The side wall of the housing 211 is adjacent to the opening of the housing 211; or the pressure release mechanism 213 may also be mounted on the cover plate 212. Embodiments of the present application are not limited to this.

[0105] Specifically, the housing 211 shown in FIG. 4, which is a hollow cuboid, is taken as an example for description. Accordingly, the battery box is also a hollow cuboid. For example, FIG. 5 shows a schematic diagram of a battery box 21. As shown in FIG. 5, since the cuboid (ie, hexagonal) battery box 21 is exemplified, the battery box 21 includes six walls (or six surfaces). In fig. 5 shows any three adjacent walls of the battery box 21, and the pressure release mechanism 213 in embodiments of the present application may be provided on any wall of the battery box 21. In this case, any of the walls is called a first wall, and the first wall may be provided with a through hole. The pressure relief mechanism 213 is located at a corresponding location of the through hole on the first wall. For example, the pressure relief mechanism 213 may be partially located in the through hole. For example, FIG. 4 shows an example in which the pressure relief mechanism 213 is located on the bottom wall of the housing 211, that is, the first wall in FIG. 5 may be the bottom wall of the housing 211. As another example, as shown in FIG. 6, the mechanism The pressure relief 213 may also be located on any side wall of the housing 211, that is, the first wall in FIG. 5 may be a side wall of the housing 211, but embodiments of the present application are not limited to this.

[0106] In embodiments of the present application, the battery box 21 is a cuboid, and the housing 211 has four side walls, including two side walls with a larger area and two side walls with a smaller area. In the case where the pressure relief mechanism 213 is located on the side wall of the housing 211, the pressure relief mechanism 213 is usually located on the side wall with a smaller area, for example, as shown in FIG. 6. Considering that a plurality of battery cells are assembled into a battery, for example, according to the installation method shown in FIG. 3, for a cube-shaped battery cell, two adjacent battery cells are generally arranged such that the larger area walls in the side walls of the housings in the two battery cells are in contact with each other. Therefore, if the pressure relief mechanism 213 is located on a side wall with a larger area, the opening of the pressure relief mechanism 213 will be affected when a plurality of battery cells are tightly arranged to be assembled into a battery. For example, it is necessary to leave space between the battery cells to open the pressure release mechanism 213, which is not conducive to installing a plurality of battery cells. Therefore, installing the pressure relief mechanism 213 on the side wall with a smaller area facilitates the placement of a plurality of battery cells and can further increase the energy density of the battery.

[0107] For ease of description, the following description will mainly take as an example the pressure relief mechanism 213 located on the bottom wall of the housing 211.

[0108] In FIG. 7 is a top view of the battery cell 20, that is, FIG. 7 shows the surface of the cover plate 212 of the battery cell 20, and FIG. 8 is a cross-sectional view of the battery cell 20 in the direction AA' shown in FIG. 7. As shown in FIG. 8, after assembling the battery cell 20, an electrode assembly 224 and an insulating sheet 223 wrapping the electrode assembly 224 are placed inside the housing 211. The backing plate 24 is located on the inner surface of the bottom wall of the housing 211 under the electrode assembly 224, the cover plate 212 covers and closes the opening of the housing 211, and the pressure release mechanism 213 is located under the battery box 21, that is, the bottom wall of the housing 211.

[0109] Considering that the thickness of each component of the pressure relief mechanism 213 in the embodiments of the present application can be set according to actual applications, the overall thickness of the pressure relief mechanism 213 may be larger. When the pressure relief mechanism is installed on the battery box 21, for example, as shown in FIG. 8, there may be a portion of the pressure release mechanism 213 that protrudes from the outer surface of the bottom portion of the entire battery cell 10.

[0110] In particular, the thickness of the pressure relief mechanism 213 in embodiments of the present application is typically larger and the thickness of the housing 211 is smaller, for example, the thickness of the bottom wall of the housing 22 is typically 1.5 mm to 2.5 mm, for example, it may be 1.5 mm, 2 mm or 2.5 mm, thus the battery cell 20 after installing the pressure relief mechanism 213 may be as shown in FIG. 8, and a portion of the pressure release mechanism 213 may protrude from the outer surface of the lower portion of the entire battery cell 10. Therefore, when the battery cell 20 shown in FIG. 8 is assembled into the battery 10, it is necessary to provide a bypass area for the pressure relief mechanism 213 protruding from the bottom of the battery cell 20. In embodiments of the present application, "mm" denotes millimeter.

[0111] For example, suppose that when assembling the battery cell 20 into the battery 10, it is necessary to place a certain component below the battery cell 20, for example, a cooling plate may be provided to cool the battery cell 20, or a bottom protection plate may also be provided. The embodiments of the present application are not limited to this. For components that are below the battery cell 20, the battery cell 20 can be mounted by providing a recessed bypass area on the surface. For example, if the cooling plate is located below the battery cell 20, a recess or through hole may be located in an area corresponding to the pressure relief mechanism 213 on the cooling plate, so that the pressure relief mechanism 213 may be located in the recess or through hole compared to the protruding portion of the lower outer surface of the battery cell 20, thereby saving space.

[0112] In addition, considering that when the pressure relief mechanism 213 is located on the bottom wall of the housing 211, the support plate 24 located on the bottom wall will cover the pressure release mechanism 213, due to which the support plate 24 may prevent gas from rushing through pressure relief mechanism 213, a bypass zone may be provided on the support plate 24 to ensure that the support plate 24 does not block the pressure relief mechanism 213. Specifically, as shown in FIG. 9, the cuboid support plate 24 is given as an example for description. Part of the area of the support plate 24 can be removed, that is, at the location of the pressure relief mechanism 213, a through hole is accordingly provided on the support plate 24, which functions as a bypass area 241, so that the support plate 24 does not block the pressure release area. For example, as shown in FIG. 9, the support plate 24 is provided with a bypass zone 241 corresponding to the pressure relief mechanism 213, so that the support plate 24 does not block the pressure relief mechanism 213, and the shape of the bypass zone 241 on the support plate 24 generally corresponds to the shape of the side surface. a pressure relief mechanism 213 near the inside of the housing 211. FIG. 9 is just an example, and embodiments of the present application are not limited to this.

[0113] Additionally, to completely prevent the pressure relief mechanism 213 from being blocked by the support plate 24, the area of the bypass zone 241 of the support plate 24 is generally set to be larger than the area of the pressure relief mechanism 213. Alternatively, given that the pressure relief mechanism 213 in the embodiments of the present application is located in the through hole of the bottom wall of the housing 211, the area of the bypass zone 241 of the support plate 24 is larger than the area of the through hole of the bottom wall of the housing 211. However, the embodiments of the present application are not limited to this.

[0114] The pressure release mechanism in embodiments of the present application will be described in detail below with reference to the accompanying drawings. In particular, as shown in FIG. 10 and fig. 11, the pressure relief mechanism 213 located on the battery box 21 in embodiments of the present application may include: a coupling mechanism 2131, a pressure relief sheet 2132, a first protective sheet 2133, a compression ring 2134, and a clamping structure 2135. Specifically, the coupling mechanism includes an opening 2131a and a first boss 2131b, wherein the first boss 2131b is connected to the inner wall of the opening 2131a and extends to the axis of the opening 2131a. The pressure relief sheet 2132 is located on the side of the first bulge 2131b, and the first protective sheet 2133 is located on the other side of the first bulge 2131b away from the pressure relief sheet 2132, and the pressure relief sheet 2132 is operable to reduce the internal pressure of the battery box when the internal pressure reaches a threshold value, and the first protective sheet 2133 is configured to protect the pressure relief sheet 2132. For the side of the first bulge 2131b where the first protective sheet 2133 is located, the side of the first protective sheet 2133 away from the first bulge 2131b is provided with a compression ring 2134 for pressing the first protective sheet 2133. The pressing structure 2135 is connected to the connecting mechanism and is capable of being pressed in the axial direction of the opening 2131a for in order to press the compression ring 2134, while in FIG. 10 is a schematic view of the clamping structure before it is pressed, and FIG. 11 is a schematic illustration of the clamping structure after it has been pressed.

[0115] Considering that the electrode clamps are generally located on the cover plate 212, if the pressure relief mechanism 213 is also located on the cover plate, when thermal runaway occurs inside the battery cell, the pressure release mechanism cracks, and the liquid or solid combustible material, which may also contain conductive material is expelled when the internal gas pressure in the battery cell decreases, causing a short circuit between the electrode terminals. Moreover, given that the electrode clamps generally face upward, that is, towards the passenger side, when the battery is installed in the vehicle, if the pressure release mechanism 213 is installed on the same side as the electrode clamps, gas flow and other materials are released after cracking pressure relief mechanism 213 will be ejected upward, which may cause burns or scalding to the occupant, increasing the risk to the occupant. Therefore, the pressure relief mechanism 213 in embodiments of the present application may be located on the bottom wall or side wall of the housing 211 of the battery box 21. For example, the pressure relief mechanism 213 after installation may be as shown in FIG. 8.

[0116] Thus, in the pressure relief mechanism according to embodiments of the present application, the protective sheet is located on the side of the pressure relief sheet that is closer to the inside of the battery box, so that when the pressure relief sheet is used with the battery box, it can prevent the relief sheet from directly contacting pressure with the electrolyte solution in the battery box, thereby reducing the corrosion of the pressure relief sheet caused by the electrolyte solution, and also reducing the influence of the electrolyte solution on the pressure relief sheet. In addition, in the installation process, by providing a bulge on the inner wall of the opening of the connecting mechanism and placing a protective sheet and a pressure relief sheet on both sides of the bulge, respectively, the pressure relief mechanism can be installed on both sides at the same time to simplify the installation process. On the side where the protective sheet is installed, the protective sheet can be pressed by the compression ring, and then the compression ring is pressed by the pressing structure. The overall design is simple and easy to operate.

[0117] In addition, given that the pressure release mechanism 213 is mounted on the battery box 21, a boss may be located on the outside of the pressure release mechanism 213 to facilitate locking. In particular, as shown in FIG. 12 (pressure structure 2135 in FIG. 12 is shown before it is pressed down) and FIG. 13 (the pressing structure 2135 in FIG. 13 is shown after it has been pressed), the connecting mechanism 2131 may further include a second boss 2131c. The second boss 2131c is connected to the outer wall of the connecting mechanism 2131 and extends from the axis of the opening 2131a. The second boss 2131c is configured to install a pressure relief mechanism on the battery box 21.

[0118] Considering that when installing the pressure relief mechanism 213, the first protective sheet 2133 is closer to the inside of the battery box 21 than the pressure relief sheet 2132, as shown in FIG. 10-13, the second boss 2131c may be located at the end of the connecting mechanism 2131 near the pressing structure 2135. Thus, when the pressure relief mechanism 213 is installed on the wall of the battery box 21, as shown in FIG. 8, for example, the surface of the pressure relief mechanism 213 near the inside of the battery box 21 can be substantially flush with the inner wall surface where the pressure relief mechanism is located so that the installation of components such as the electrode assembly 22 and the support plate 24 within the battery box 21 is not affected, thereby saving internal space .

[0119] In addition, to improve the sealing performance of the first protective sheet 2133, a spacer may be provided between the first protective sheet 2133 and the first thickening 2131b. In particular, as shown in FIG. 12 and FIG. 13, the pressure relief mechanism 213 may further include an annular spacer 2136 disposed between the first protective sheet 2133 and the first boss 2131b, thereby improving the sealing performance of the first protective sheet 2133.

[0120] Considering that when installing the pressure relief mechanism 213 on the battery box 21, the pressure relief sheet 2132 is located away from the inside of the battery box 21 compared with the first protective sheet 2133, or the pressure relief sheet 2132 is located on the outside of the battery box 21, and to prevent influence on the pressure relief sheet 2132 of other components outside the battery box, as shown in FIGS. 12-13, the pressure relief mechanism 213 may further comprise a second protective sheet 2137 configured to protect the pressure relief sheet 2132. The second protective sheet 2137 is mounted on the connecting mechanism 2131, and is located on the side of the pressure relief sheet 2132 away from the first boss 2131b, and covers the pressure relief sheet 2132.

[0121] It should be understood that the size of the pressure relief mechanism 213 in embodiments of the present application can be flexibly set in accordance with actual applications. The following description will give examples of the dimensions of the pressure relief mechanism 213 and its various components included in embodiments of the present application with reference to FIGS. 14-22.

[0122] For example, in FIG. 14 is a schematic top view of the pressure release mechanism 213 before the pressing structure 2135 is pressed. The shape of the pressure release mechanism 213 in the embodiments of the present application can be flexibly set according to actual applications. For example, taking as an example the shape of the top surface in the top view of the pressure relief mechanism and considering that the housing 211 is a cuboid, if the pressure relief mechanism 213 is located on the bottom wall of the housing 211, due to the limitation of the shape of the bottom wall, the pressure relief mechanism 213 is usually may be arranged in the form of a treadmill, as shown in FIG. 14. The shape of a treadmill is like an ellipse, with arcs at both ends but a straight line in the middle. Alternatively, the pressure relief mechanism 213 may also take other forms. The embodiments of the present application are not limited to this.

[0123] In FIG. 15 is a cross-sectional view in the direction B-B' shown in FIG. 14. As shown in FIG. 15, for ease of description, it is assumed that the direction of the pressure relief mechanism 213 is set as shown in FIG. 15. The upper surface and the lower surface described below depend on the direction shown in FIG. 15, while the upper portion of the pressure release mechanism 213 in FIG. 15 corresponds to the inside of the battery box 21 when the pressure relief mechanism 213 is installed in the battery box 21, and the lower part of the pressure relief mechanism 213 in FIG. 15 corresponds to the outside of the battery box 21. For example, in this case, the second boss 2131 of the pressure relief mechanism 213 is located above, that is, the second boss is at the end of the connecting mechanism 2131 near the compression ring 2134. However, embodiments of the present application are not limited to this.

[0124] In particular, when the pressure relief mechanism 213 is mounted on the housing 211, for example, the pressure relief mechanism is mounted on the first wall of the housing 211, and the first wall of the housing 211 is provided with a through hole. The pressure relief mechanism 213 is located on the first wall by the connecting mechanism 2131 and is positioned in accordance with the through hole for actuation to reduce the internal pressure of the battery box when the internal pressure reaches a threshold value. Regarding the installation direction of the pressure relief mechanism 213, the pressing structure 2135 is closer to the inside of the housing than the pressure relief sheet 2132. Specifically, taking as an example the installation of the pressure relief mechanism 213 shown in FIG. 15, the third recess may be provided on the side surface of the first wall near the inside of the housing 211, that is, the third recess is provided on the outer surface of the first wall. The through hole is located on the bottom wall of the third recess, and in this case, the second boss 2131 c of the connecting mechanism 2131 is installed on the bottom wall of the third recess, so that the pressure release mechanism 213 is at least partially located in the through hole, that is, the bottom surface of the second boss 2131 c , shown in Fig. 15, is in contact with and attached to the bottom wall of the third recess. However, since the hole of the third recess faces the inside of the housing 211, the pressure relief mechanism 213 is installed from the inside of the housing 211, so installation is difficult due to the depth of the housing 211.

[0125] In contrast, installation of the pressure relief mechanism 213 may also include: providing a sixth recess on a side surface of the first wall away from the interior of the housing 211, that is, providing a sixth recess on the outer surface, and wherein a through hole is provided in the bottom wall of the sixth recess; and then installing the second boss 2131 from the connecting mechanism 2131 on the bottom wall of the sixth recess so that the pressure relief mechanism 213 is at least partially located in the through hole. That is, the upper surface of the second boss 2131c shown in FIG. 15 is in contact with and attached to the bottom wall of the sixth recess. Moreover, since the hole of the sixth recess faces away from the inside of the body 211, that is, faces outside the body 211, the pressure relief mechanism 213 is installed on the outside of the body 211 through the second thickening 2131 c, which is more convenient for installation.

[0126] As shown in FIG. 15, for the upper surface of the pressure relief mechanism 213 shown in FIG. 15, the upper surface of the connecting mechanism 2131 and the upper surface of the compression ring 2134 may be flush. Thus, only the pressure structure 2135 protrudes upward on the top surface of the pressure release mechanism 213, but the pressure structure 2135 will be pressed and may be positioned flush with the compression ring 2134 after it is pressed. That is, when the pressure relief mechanism 213 shown in FIG. 15 is mounted on the battery box 21, the upper surface of the pressure release mechanism 213 may be flush with the inner surface of the battery box 21 so as not to affect the installation of the internal electrode assembly and other components of the battery box.

[0127] As shown in FIG. 15, the thickness of the connecting mechanism 2131 can be set according to actual applications. For example, given that it is necessary to install many components on the connecting mechanism 2131, the thickness h1 of the connecting mechanism 2131 along the axial direction of the opening 2131a is usually 4.05 mm to 5.05 mm, for example, it may be 4.05 mm, 4.55 mm or 5.05 mm, wherein, as shown in Fig. 15, the thickness h1 is the thickness of the thickest region of the connecting mechanism 2131, that is, including the pressing structure 2135 before it is pressed. The thickness h2 of the first boss 2131b on the connecting mechanism 2131 may generally be from 1.25 mm to 1.45 mm, for example, it may be 1.25 mm, 1.35 mm or 1.45 mm; As for the thickness h3 of the second thickening 2131c on the connecting mechanism 2131, it may generally be from 0.6 mm to 0.9 mm, for example, it may be 0.6 mm, 0.8 mm or 0.9 mm.

[0128] As shown in FIG. 15, the thickness h4 of the second protective sheet 2137 located under the pressure relief sheet 2132 in embodiments of the present application may generally be from 0.1 mm to 0.2 mm, for example, it may be 0.1 mm, 0.15 mm or 0.2 mm. The second protective sheet 2137 may be attached to a side of the connecting mechanism 2131 away from the first thickening 2131b of the pressure relief sheet 2132 by gluing, for example, it may be attached to the bottom surface of the connecting mechanism 2131. When the pressure relief sheet 2132 is worn, a certain opening space is required to In order for the pressure relief sheet 2132 to crack and open, it is therefore necessary to provide a gap between the surface of the second protective sheet 2137 in the direction towards the pressure relief sheet 2132 and the surface of the pressure relief sheet 2132 in the direction towards the second protective sheet 2137. For example, the gap size h5 can generally be greater than or equal to 0.5 mm, for example it could be 0.5 mm, 1 mm or 2 mm. Thus, the pressure relief sheet 2132 can also be protected to prevent the pressure relief sheet 2132 from being compressed by components in the battery when the battery cell is assembled into the battery.

[0129] In order to provide clearance between the pressure relief sheet 2132 and the second protective sheet 2137, a recess may be provided on the bottom surface of the connecting mechanism 2131. Specifically, in FIG. 16 is a schematic representation of the coupling mechanism 2131 shown in FIG. 15. As shown in FIG. 16, a fourth recess a is provided on the side surface of the connecting mechanism 2131 near the pressure relief sheet 2132, a fifth recess b is provided on the bottom wall of the fourth recess a, and an opening 2131a of the connecting mechanism 2131 is provided on the bottom wall of the fifth recess b, so that the side of the connecting mechanism 2131 is proximate The pressure relief sheet 2132 is formed with a stepped structure. That is, the bottom wall of the fifth recess b is a side surface of the first bulge 2131b for receiving the pressure relief sheet 2132, and the depth of the fifth recess b can be set equal to the thickness of the pressure relief sheet 2132. In contrast, as shown in FIG. 15, the bottom surface of the pressure relief sheet 2132 may be flush with the surface of the bottom wall of the fourth recess a. At the same time, the depth of the fourth recess a is equal to the separation distance between the pressure relief sheet 2132 and the second protective sheet 2137 below.

[0130] In FIG. 17 is a partial enlarged view of the area A1 shown in FIG. 15. As shown in FIG. 17, the thickness h6 of the compression ring 2134 in embodiments of the present application may generally be from 1 mm to 1.2 mm, for example, it may be 1 mm, 1.1 mm or 1.2 mm. The thickness h7 of the first protective sheet 2133 in embodiments of the present application may generally be from 0.3 mm to 0.5 mm, for example, it may be 0.3 mm, 0.4 mm or 0.5 mm. The thickness h8 of the ring spacer 2136 in embodiments of the present application may typically be from 0.2 mm to 0.4 mm, for example, it may be 0.2 mm, 0.3 mm or 0.4 mm. With respect to the pressing structure 2135 in embodiments of the present application, the pressing structure 2135 may be a protruding structure that projects upward relative to the upper surface of the pressure release mechanism 213 before being pressed. As shown in FIG. 17, the shape of the protruding structure can be flexibly set according to actual applications. For example, taking the protruding cuboid structure as an example here, the length h9 of the pressing structure 2135 may generally be from 0.4 mm to 0.6 mm, for example, it may be 0.4 mm, 0.5 mm or 0.6 mm; and the height H0 at which the pressing structure 2135 protrudes relative to the top surface of the coupling mechanism 2131, in other words, the height h10 at which the pressing structure 2135 protrudes relative to the side surface of the coupling mechanism 2131 near the compression ring 2134 can generally be from 0.3 mm to 0 .5 mm, for example, it can be 0.3 mm, 0.4 mm or 0.5 mm.

[0131] The size of the pressure relief sheet 2132 in embodiments of the present application will be specified below. The pressure relief sheet 2132 in embodiments of the present application may be attached to one side of the first boss 2131b by welding, for example laser welding may be used. In addition, a uniform sheet-shaped structure may be used in the pressure relief sheet 2132. Alternatively, considering that when thermal runaway occurs inside the battery cell, in order to facilitate cracking of the pressure relief sheet 2132, a recess may be added on the surface of the pressure relief sheet 2132, that is, a recess area is provided on the surface of the pressure relief sheet 2132. The thickness within the recess is thinner so that the pressure release mechanism can crack within the recess to achieve more precise directional cracking and release. In addition, considering the ease of installation, the connection between the pressure relief sheet and the connecting mechanism does not need to be made too thin, so a plurality of recesses can be provided on the pressure relief sheet 2132. In particular, in FIG. 18 shows a schematic illustration of a pressure relief sheet 2132. As shown in FIG. 18, the first recess 2132-1 may be provided on an upper surface and/or a lower surface of the pressure relief sheet 2132 having a sheet shape. In fig. 18 illustrates as an example the first recess 2132-1 provided on the bottom surface of the pressure relief sheet 2132 corresponding to FIG. 15, that is, a side surface of the pressure relief sheet 2132 away from the first protective sheet 2133 and/or a side surface of the pressure relief sheet near the first protective sheet 2133 may be provided with a first recess. Moreover, the second recess 2132-2 may be provided on the bottom wall of the first recess 2132-1, for example, as shown in FIG. 18, therefore, when the internal pressure of the battery box 21 reaches a threshold value, the pressure relief sheet 2132 cracks on the second recess 2132-2 to reduce the internal pressure, wherein the bottom wall of the recess in the embodiments of the present application refers to the wall opposite the opening of the recess, and the side wall of the recess refers to the wall adjacent to the hole.

[0132] To facilitate cracking of the pressure relief sheet 2132 when thermal runaway occurs inside the battery cell, a recess may be added to the surface of the pressure relief sheet 2132, that is, a second recess area 2132-2 is provided on the surface of the pressure relief sheet 2132. The thickness within the second recess 2132-2 is smaller, the second recess 2132-2 can cause the pressure relief sheet 2132 to crack at a predetermined position to reduce the internal pressure, that is, the cracking location of the pressure relief sheet 2132 is more precise, and directional cracking can be achieved.

[0133] It should be understood that the first recess in embodiments of the present application is generally provided on a side surface of the pressure relief sheet 2132 away from the first protective sheet 2133. The reason for this is that during installation, the side of the pressure relief sheet 2132 is adjacent to the first protective sheet 2133 faces the inside of the battery box 21. If the recess is located on this side, since there is an electrolyte solution in the battery box 21, if the seal of the first protective sheet 2133 is not good enough, the electrolyte solution may flow between the first protective sheet 2133 and the pressure relief sheet 2132, thereby accumulating in the recess on the surface of the pressure relief sheet 2132 and causing corrosion of the recessed portion, which may cause premature cracking of the pressure relief sheet 2132. Therefore, a recess is generally provided on a side of the pressure relief sheet 2132 away from the first protective sheet 2133, which can reduce corrosion caused by the electrolyte solution.

[0134] As shown in FIG. 18, the thickness h11 of the pressure relief sheet 2132 in embodiments of the present application may generally be from 0.3 mm to 1 mm, for example, it may be 0.3 mm, 0.5 mm or 1 mm. The depth hl2 of the first recess 2132-1 may generally be from 0.2 mm to 0.4 mm, for example, it may be 0.2 mm, 0.3 mm or 0.4 mm. The thickness hl3 of the pressure relief sheet 2132 on the second recess 2132-2 may generally be from 0.08 mm to 0.15 mm, for example, it may be 0.08 mm, 0.1 mm or 0.15 mm. In addition, the shapes of the bottom wall of the first recess and the bottom wall of the second recess can be set according to actual applications. For example, the bottom wall of the first recess may be circular, and the bottom wall of the second recess may be rectangular, circular, semicircular, or other shape. The embodiments of the present application are not limited to this.

[0135] It should be understood that the foregoing descriptions generally give the corresponding dimensions of the pressure relief mechanism 213 in the embodiments of the present application in the thickness direction. Other dimensions of the pressure relief mechanism 213 can also be set reasonably according to actual applications. For example, the shape of the pressure relief mechanism 213 shown in FIG. 14 is still given here as an example. Fig. 19 corresponds to Fig. 15 and is also a cross-sectional view in the direction B-B'. As shown in FIG. 19, the total area of the pressure relief mechanism 213 can typically be between 400 square meters. mm up to 1500 sq. mm, for example, it can be 400 sq. mm, 1000 sq. mm or 1500 sq. mm. The overall length L1 of the pressure relief mechanism 213 may generally be from 36 mm to 68 mm, for example, it may be 36 mm, 50 mm or 68 mm. Without taking into account the part of the second boss 2131 c protruding from the periphery of the pressure relief mechanism 213, the length L2 is generally from 32 mm to 64 mm, for example, it may be 32 mm, 45 mm or 64 mm. According to the above, in order to facilitate installation of the pressure relief sheet 2132, a fourth recess may be provided on the bottom surface of the connecting mechanism 2131. The corresponding length L3 of the fourth recess is generally 28 mm to 60 mm, for example, it may be 28 mm, 40 mm or 60 mm. A fifth recess is provided in the fourth recess for mounting the pressure relief sheet 2132 on the bottom wall of the fifth recess. The area of the pressure relief sheet 2132 can typically be between 200 sq. mm up to 1300 sq. mm, for example, it can be 200 sq. mm, 750 sq. mm or 1300 sq. mm. The length L4 of the pressure relief sheet 2132 may generally be from 26 mm to 58 mm, for example, it may be 26 mm, 40 mm or 58 mm. For the first boss 2131b, the length L5 of the opening 2131a of the connecting mechanism 2131 may generally be from 22 mm to 54 mm, for example, it may be 22 mm, 40 mm or 54 mm. However, the embodiments of the present application are not limited to this. In embodiments of this application, “sq. mm" stands for square millimeter.

[0136] Above with reference to FIG. 14-19 describe respective components of the pressure release mechanism 213 according to embodiments of the present application before the pressing structure 2135 is pressed. Next, with reference to FIGS. 20 to 22, corresponding components of the pressure release mechanism 213 according to embodiments of the present application after pressing the pressure structure 2135 will be described.

[0137] Specifically, in FIG. 20 is a top view of the pressure release mechanism 213 shown in FIG. 13 after pressing the pressing structure 2135; in fig. 21 is a cross-sectional view in the direction D-D' shown in FIG. 20, that is, in FIG. 21 is a cross-sectional view of the pressure release mechanism 213 after pressing the pressure structure 2135.

[0138] The clamping structure 2135 in embodiments of the present application may include at least one projection structure, and the at least one projection structure is located on a side surface of the coupling mechanism 2131 adjacent to the compression ring 2134 and protrudes in a direction away from the compression ring 2134. The clamping structure 2135 after pressing it, it can extend to the axis of the opening 2131a relative to the inner wall of the opening 2131a. Typically, the clamping structure 2135 may be configured to include a plurality of protruding structures spaced apart from each other. For example, as shown in FIG. 20, in this case, six protruding structures are provided as an example, and the six protruding structures may be evenly or symmetrically arranged at the edge of the opening 2131a of the pressure relief mechanism 213. This ensures that only six protruding structures need to be pressed during pressing. Compared with the 2135 pressing structure, which is made as a circle of continuous protruding structures, the pressing process is more convenient and easier to operate. The width of each pressing structure 2135 can be set reasonably in accordance with the size of the pressure relief mechanism 213 . For example, as shown in FIG. 20, the width L4 of the clamping structure 2135 may be from 2 mm to 4 mm, for example, it may be 2 mm, 3 mm or 4 mm.

[0139] It should be understood that the size of the pressing structure 2135 before and after it is pressed can be set in accordance with actual applications. For example, in FIG. 17 exemplifies the size of the pressing structure 2135 before it is pressed, and accordingly, after it is pressed, the size of the pressing structure 2135 may be as shown in FIG. 20. The distance h15 that the pressing structure 2135 extends to the axis of the opening 2131a relative to the inner wall of the opening 2131a may generally be from 0.8 mm to 1 mm, for example, it may be 0.8 mm, 0.9 mm or 1 mm .

[0140] As shown in FIG. 21, the pressing structure 2135 is deformed after being pressed, and may assume any regular or irregular shape, and after the pressing structure 2135 is deformed, the pressing structure 2135 will extend to the axial direction of the opening 2131a of the connecting mechanism 2131 to press the compression ring 2134. For example, in FIG. 22 is an enlarged view of the area A2 shown in FIG. 21. As shown in FIG. 22, the pressing structure 2135 may be shaped like a triangle after being deformed to press the compression ring 2134. However, embodiments of the present application are not limited to this.

[0141] It should be understood that in addition to the sizes of the components in the above-described pressure relief mechanism 213, the material of each component in the embodiments of the present application can also be set according to actual applications. For example, compression ring 2134 in embodiments of the present application may typically be an aluminum compression ring. The first protective sheet 2133 in embodiments of the present application may typically be a polypropylene film, polyethylene film, or polyethylene terephthalate film, but embodiments of the present application are not limited to this.

[0142] The pressure relief mechanism, battery box, battery cell and battery according to embodiments of the present application are described above with reference to FIGS. 1-22. A method and apparatus for manufacturing a pressure relief mechanism according to embodiments of the present application will be described below with reference to FIGS. 23 and fig. 24.

[0143] Specifically, in FIG. 23 is a flow diagram of a method 200 for manufacturing a pressure relief mechanism according to one embodiment of the present application. As shown in FIG. 23, method 200 may include: S210, providing a connecting mechanism, wherein the connecting mechanism includes an opening and a first boss, wherein the first boss is connected to an inner wall of the opening and extends to an axis of the opening; S220, providing a pressure relief sheet for actuation to reduce the internal pressure of the battery box when the internal pressure reaches a threshold value, the pressure relief sheet being located on one side of the first bulge; S230, providing a first protective sheet for protecting the pressure relief sheet and located on the other side of the first bulge away from the pressure relief sheet; S240, providing a compression ring for pressing the first protective sheet and located on a side of the first protective sheet away from the first bulge; S250, providing a pressing structure connected to the connecting mechanism and capable of pressing against the axis of the opening in order to press the compression ring.

[0144] Optionally, in one embodiment, the clamping structure includes at least one projection structure, and the at least one projection structure is located on a side surface of the coupling mechanism adjacent to the compression ring and protrudes in a direction away from the compression ring.

[0145] Optionally, in one embodiment, the pressing structure, after being pressed, extends toward the axis of the opening relative to the inner wall of the opening.

[0146] Optionally, as one embodiment, the coupling mechanism further comprises a second boss, the second boss being coupled to an outer wall of the coupling mechanism and extending away from the axis of the opening, and the second boss being used to install the pressure relief mechanism on the battery box.

[0147] It should be understood that the method 200 according to an embodiment of the present application can be used to manufacture the pressure relief mechanism 213 according to embodiments of the present application, which will not be repeated here for brevity.

[0148] It should be understood that in the various embodiments of the present application, the order number of the above processes does not indicate the order of execution, and the order of execution of the processes should be determined by their function and internal logic, and should not constitute any limitation on the process of implementing the embodiments implementation of this application.

[0149] In FIG. 24 is a block diagram of an apparatus 300 for manufacturing a pressure relief mechanism according to one embodiment of the present application. As shown in FIG. 24, the apparatus 300 according to an embodiment of the present application includes: a providing module 310, wherein the providing module 310 is used to: provide a connecting mechanism, wherein the connecting mechanism includes an opening and a first boss, wherein the first boss is connected to an inner wall of the opening and extends to the axis of the opening; providing a pressure relief sheet for actuation to reduce the internal pressure of the battery box when the internal pressure reaches a threshold value, the pressure relief sheet being disposed on one side of the first bulge; providing a first protective sheet for protecting the pressure relief sheet and located on the other side of the first boss away from the pressure relief sheet; providing a compression ring for pressing the first protective sheet and located on a side of the first protective sheet away from the first thickening; and providing a pressing structure coupled to the connecting mechanism and capable of pressing against the axis of the opening to press the compression ring.

[0150] Optionally, in one embodiment, the clamping structure includes at least one projection structure, and the at least one projection structure is located on a side surface of the coupling mechanism adjacent to the compression ring and protrudes in a direction away from the compression ring.

[0151] Optionally, in one embodiment, the pressing structure, after being pressed, extends toward the axis of the opening relative to the inner wall of the opening.

[0152] Optionally, as one embodiment, the coupling mechanism further comprises a second boss, the second boss being coupled to an outer wall of the coupling mechanism and extending away from the axis of the opening, and the second boss being used to install the pressure relief mechanism on the battery box.

[0153] It should be understood that the apparatus 300 according to an embodiment of the present application may correspond to implementation of the method 200 in the embodiment of the present application, and the above and other operations and/or functions of each block in the apparatus 300 are respectively designed to implement the corresponding processes of the method 200 shown in fig. 23, which will not be repeated here for brevity.

[0154] Finally, it should be noted that the above embodiments are used only to illustrate and not limit the technical solutions of the present application. Although the present application is illustrated in detail with reference to the above embodiments, it will be understood by those skilled in the art that they may still modify the technical solutions described in the previous embodiments or make equivalent substitutions for some of the technical features described herein. but these changes or substitutions may be made to the corresponding technical solutions without departing from the essence and scope of the technical solutions of the embodiments of the present application.

Claims (73)

1. A pressure relief mechanism for a battery box, comprising: a coupling mechanism (2131), wherein the coupling mechanism (2131) contains an opening (2131a) and a first boss (2131b), wherein the first boss (2131b) is connected to the inner wall of the opening (2131a) and extends to the axis of the opening (2131a); a pressure relief sheet (2132) operable to reduce the internal pressure of the battery box when the internal pressure reaches a threshold value, the pressure relief sheet (2132) being located on one side of the first boss (2131b); a first protective sheet (2133) configured to protect the pressure relief sheet (2132) and located on the other side of the first thickening (2131b) away from the pressure relief sheet (2132); a compression ring (2134) configured to press the first protective sheet (2133) and located on a side of the first protective sheet (2133) away from the first thickening (2131b); And a clamping structure (2135) connected to the connecting mechanism (2131) and capable of being pressed against the axis of the opening (2131a) in order to press the compression ring (2134). 2. The pressure relief mechanism according to claim 1, characterized in that the clamping structure (2135) includes at least one protruding structure, and at least one protruding structure is located on the side surface of the connecting mechanism (2131) near the compression ring (2134) and protrudes away from the compression ring (2134). 3. The pressure relief mechanism according to claim 2, characterized in that the at least one protruding structure represents a plurality of protruding structures spaced apart from each other. 4. The pressure relief mechanism according to claim 2 or 3, characterized in that the height to which the protruding structure protrudes relative to the side surface of the connecting mechanism (2131) near the compression ring (2134) is from 0.3 mm to 0.5 mm. 5. The pressure relief mechanism according to claim 1, characterized in that the clamping structure (2135), after being pressed, extends to the axis of the opening (2131a) relative to the inner wall of the opening (2131a). 6. The pressure relief mechanism according to claim 5, characterized in that the clamping structure (2135), after being pressed, extends to the axis of the opening (2131a) at a distance of 0.8 mm to 1 mm relative to the inner wall of the opening (2131a). 7. The pressure relief mechanism according to claim 1, characterized in that the thickness of the first thickening (2131b) is from 1.25 mm to 1.45 mm. 8. The pressure relief mechanism according to claim 1, characterized in that the thickness of the pressure relief sheet (2132) is from 0.3 mm to 1 mm. 9. The pressure relief mechanism according to claim 1, characterized in that the thickness of the first protective sheet (2133) is from 0.3 mm to 0.5 mm. 10. Pressure relief mechanism according to claim 1, characterized in that the thickness of the compression ring (2134) is from 1 mm to 1.2 mm. 11. The pressure relief mechanism according to claim 1, characterized in that the thickness of the connecting mechanism (2131) along the axial direction of the opening (2131a) is from 4 mm to 5 mm. 12. The pressure relief mechanism according to claim 1, characterized in that the connecting mechanism (2131) further comprises a second thickening (2131 c), wherein the second thickening (2131 c) is connected to the outer wall of the connecting mechanism (2131) and extends from the axis of the opening ( 2131a), and the second thickening (2131c) is configured to install a pressure relief mechanism on the battery box. 13. The pressure relief mechanism according to claim 12, characterized in that the second thickening (2131 c) is located at the end of the connecting mechanism (2131) near the clamping structure (2135). 14. Pressure relief mechanism according to claim 12 or 13, characterized in that the thickness of the second thickening (2131 s) ranges from 0.6 mm to 0.9 mm. 15. The pressure relief mechanism according to claim 1, characterized in that the side surface of the pressure relief sheet (2132) away from the first protective sheet (2133) and/or the side surface of the pressure relief sheet near the first protective sheet (2133) is/is provided with a first recess (2132-1), the bottom wall of the first recess (2132-1) is provided with a second recess (2132-2), and the pressure relief sheet (2132) is configured to crack at the second recess (2132-2) to reduce the internal pressure of the battery box, when internal pressure reaches a threshold value. 16. The pressure relief mechanism according to claim 15, characterized in that the first recess (2132-1) is located on the side surface of the pressure relief sheet (2132) away from the first protective sheet (2133). 17. The pressure relief mechanism according to claim 15 or 16, characterized in that the thickness of the pressure relief sheet (2132) on the second recess (2132-2) is from 0.08 mm to 0.15 mm. 18. The pressure relief mechanism according to claim 15, characterized in that the depth of the first recess (2132-1) is 0.3 mm. 19. The pressure relief mechanism according to claim 1, characterized in that it additionally contains: a second protective sheet (2137) configured to protect the pressure relief sheet (2132), wherein the second protective sheet (2137) is mounted on the connecting mechanism (2131) and is located on a side of the pressure relief sheet (2132) away from the first thickening (2131b) , and covers the pressure relief sheet (2132). 20. The pressure relief mechanism according to claim 19, characterized in that the thickness of the second protective sheet (2137) is from 0.1 mm to 0.2 mm. 21. The pressure relief mechanism according to claim 19 or 20, characterized in that between the surface of the second protective sheet (2137) in the direction towards the pressure relief sheet (2132) and the surface of the pressure relief sheet (2132) in the direction towards the second protective sheet (2137) clearance is provided. 22. The pressure relief mechanism according to claim 21, characterized in that the gap is greater than or equal to 0.5 mm. 23. The pressure relief mechanism according to claim 1, characterized in that it additionally contains: an annular spacer (2136) located between the first protective sheet (2133) and the first thickening (2131b). 24. The pressure relief mechanism according to claim 23, characterized in that the thickness of the ring gasket (2136) is from 0.2 mm to 0.4 mm. 25. Battery box containing: a housing (211), the first wall of the housing (211) being provided with a through hole; And The pressure relief mechanism according to claim 1, wherein the pressure relief mechanism is located on the first wall by means of a connecting mechanism (2131) and is positioned in accordance with the through hole for actuation to reduce the internal pressure of the battery box when the internal pressure reaches a threshold value. 26. The battery box according to claim 25, characterized in that the clamping structure (2135) is closer to the inside of the housing (211) than the pressure relief sheet (2132). 27. The battery box according to claim 26, characterized in that a third recess is provided on a side surface of the first wall near the inside of the housing (211), and a through hole is provided on the bottom wall of the third recess, the connecting mechanism (2131) further comprises a second boss (2131 c), the second boss (2131 c) is connected to the outer wall of the connecting mechanism (2131) and extends from the axis of the opening (2131a), the second boss (2131 c) is located at the end of the connecting mechanism ( 2131) near the clamping structure (2135), and the second boss (2131 c) is mounted on the bottom wall of the third recess so that the pressure relief mechanism is at least partially located in the through hole. 28. Battery box according to any one of paragraphs. 25-27, characterized in that the body (211) is a hollow cuboid and contains a hole at the end. 29. The battery box according to claim 28, characterized in that the first wall is a lower wall of the housing (211), and the lower wall of the housing (211) is a wall opposite the opening of the housing (211). 30. Battery box according to claim 28, characterized in that the thickness of the lower wall of the housing (211) is from 1.5 mm to 2.5 mm. 31. Battery box according to claim 28, characterized in that the battery box contains: a cover plate (212) covering and closing the opening of the housing (211). 32. Battery cell containing: battery box according to item 25; And an electrode assembly (22), wherein the electrode assembly (22) is located in the battery box. 33. The battery cell according to claim 32, characterized in that the housing (211) is a hollow cuboid and contains a hole at the end. 34. Battery cell according to claim 33, characterized in that it additionally contains: a support plate (24), wherein the support plate (24) is located between the electrode assembly and the lower wall of the housing (211), and wherein the lower wall of the housing (211) is a wall of the housing (211) opposite the opening of the housing (211). 35. The battery cell according to claim 34, characterized in that the first wall is the bottom wall of the housing (211), and the support plate (24) is provided with a bypass zone (241) corresponding to the pressure release mechanism, so that the support plate (24) does not block pressure release mechanism. 36. Battery containing: a plurality of battery cells, wherein the plurality of battery cells includes at least one battery cell according to any one of claims. 32-35; a bus component configured to provide electrical connection among a plurality of battery cells; And a housing configured to receive a plurality of battery cells and a busbar component. 37. A vehicle containing a battery according to paragraph 36. 38. A method for manufacturing a pressure relief mechanism for a battery box according to claim 1, the method comprising: providing a connecting mechanism, the connecting mechanism comprising an opening and a first boss, the first boss being connected to an inner wall of the opening and extending to an axis of the opening; providing a pressure relief sheet operable to reduce the internal pressure of the battery box when the internal pressure reaches a threshold value, the pressure relief sheet being located on one side of the first boss; providing a first protective sheet configured to protect the pressure relief sheet and located on the other side of the first bulge away from the pressure relief sheet; providing a compression ring configured to compress the first protective sheet and located on a side of the first protective sheet away from the first thickening; And providing a clamping structure coupled to the coupling mechanism and capable of being pressed against the axis of the opening to press the compression ring. 39. The method of claim 38, wherein the clamping structure comprises at least one projection structure, and the at least one projection structure is located on a side surface of the coupling mechanism near the compression ring and protrudes in a direction away from the compression ring. 40. The method according to claim 38 or 39, characterized in that the clamping structure, after being pressed, extends to the axis of the opening relative to the inner wall of the opening. 41. The method according to claim 38, characterized in that the connecting mechanism further comprises a second thickening, wherein the second thickening is connected to the outer wall of the connecting mechanism and extends from the axis of the opening, and the second thickening is configured to install a pressure relief mechanism on the battery box. 42. An apparatus for manufacturing a pressure relief mechanism for a battery box according to claim 1, wherein the apparatus comprises a provision module configured to: providing a connecting mechanism, the connecting mechanism comprising an opening and a first boss, the first boss being connected to an inner wall of the opening and extending to an axis of the opening; providing a pressure relief sheet operable to reduce the internal pressure of the battery box when the internal pressure reaches a threshold value, the pressure relief sheet being located on one side of the first boss; providing a first protective sheet configured to protect the pressure relief sheet and located on the other side of the first boss away from the pressure relief sheet; providing a compression ring configured to compress the first protective sheet and located on a side of the first protective sheet away from the first thickening; And providing a clamping structure connected to the connecting mechanism and capable of being pressed against the axis of the opening to press the compression ring. 43. The apparatus of claim 42, wherein the clamping structure comprises at least one protruding structure, and the at least one protruding structure is located on a side surface of the coupling mechanism near the compression ring and protrudes in a direction away from the compression ring. 44. The device according to claim 42 or 43, characterized in that the clamping structure, after being pressed, extends to the axis of the opening relative to the inner wall of the opening. 45. The apparatus according to claim 42, characterized in that the connecting mechanism further comprises a second thickening, wherein the second thickening is connected to the outer wall of the connecting mechanism and extends from the axis of the opening, and the second thickening is configured to install a pressure relief mechanism on the battery box.