Pressure relief member, battery cell, battery, and power consumption device

Abstract

The present invention relates to a pressure relief member, a battery cell, a battery, and a power consumption device, all of which belong to the battery technology field. The pressure relief member includes a pressure relief portion, a reinforcing portion, and a first weak portion. The pressure relief portion is configured to tear when the battery cell releases pressure, thereby releasing the internal pressure of the battery cell. The reinforcing portion is connected to the pressure relief portion and surrounds the pressure relief portion. The first weak portion is connected to the pressure relief portion via the reinforcing portion, and the rigidity of the first weak portion is lower than that of the reinforcing portion. The pressure relief member employing this structure makes the first weak portion more deformable, so that when the battery cell is deformed due to internal or external impact, the first weak portion can absorb the deformation energy of the battery cell. This allows the first weak portion to perform a certain buffering function, further reducing the occurrence of deformation or breakage of the pressure relief portion, thereby improving the usability and service life of the pressure relief member.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to Chinese Patent Application No. 2023105014847, entitled "Pressure Relief Member, Battery Cell, Battery and Power Consumption Device," filed on May 6, 2023, the entire contents of which are incorporated herein by reference.

[0002] The present application relates to the field of battery technology, and more particularly to a pressure relief member, a battery cell, a battery, and a power consumption device. [Background technology]

[0003] In recent years, new energy vehicles have developed dramatically, and in the field of electric vehicles, power batteries play an irreplaceable and important role as the power source of electric vehicles. With the rapid popularity of new energy vehicles, the demand for power battery products is also increasing day by day. As a core component of new energy vehicles, batteries have relatively high requirements in terms of both usage reliability and service life.

[0004] In battery technology, to ensure the safety of battery cells, a pressure relief member is generally installed in the battery cell housing to relieve the internal pressure of the battery cell, so that when the internal pressure or temperature of the battery cell reaches a threshold, the pressure relief member can be activated to relieve the internal pressure of the battery cell. However, the pressure relief member of conventional battery cells often activates and relieves pressure prematurely during use, resulting in a relatively poor usage stability of the battery cell, which is detrimental to improving the service life and usage reliability of the battery cell. Summary of the Invention

[0005] The embodiments of the present application provide a pressure relief member, a battery cell, a battery, and a power consumption device that can effectively improve the service life and usage reliability of the battery cell.

[0006] According to a first aspect, an embodiment of the present application provides a pressure relief member for use in a battery cell, the pressure relief member including a pressure relief portion, a reinforcing portion and a first weak portion, the pressure relief portion being configured to tear when the battery cell is released from pressure to release the internal pressure of the battery cell, the reinforcing portion being connected to the pressure relief portion and being arranged to surround the pressure relief portion, the first weak portion being connected to the pressure relief portion via the reinforcing portion, and the rigidity of the first weak portion being smaller than the rigidity of the reinforcing portion.

[0007] In the above technical solution, a pressure release part, a reinforcing part, and a first weak part are sequentially connected to the pressure release member, and the reinforcing part is arranged to surround the pressure release part, and the pressure release part is connected to the first weak part via the reinforcing part. By setting the rigidity of the first weak part lower than that of the reinforcing part, the deformation resistance of the first weak part is weaker than that of the reinforcing part, making the first weak part more easily deformed. This allows the first weak part to effectively absorb the deformation energy of the battery cell when the battery cell is deformed due to internal or external impact forces. This allows the first weak part to play a certain buffering role, thereby providing a certain protective role for the pressure release part located inside the reinforcing part. Furthermore, the pressure release part of the pressure release member can effectively reduce the occurrence of phenomena such as deformation or breakage when the battery cell is subjected to internal or external impact forces. This effectively alleviates the situation where the pressure release part of the pressure release member activates early to release pressure during use, thereby improving the usage stability and service life of the pressure release member and advantageously improving the service life and usage reliability of battery cells equipped with such a pressure release member.

[0008] In some embodiments, the thickness of the first weakened portion is less than the thickness of the reinforcement portion.

[0009] In the above technical proposal, the thickness of the first weak part is set smaller than the thickness of the reinforced part, making the first weak part more easily deformable than the reinforced part, thereby realizing that the rigidity of the first weak part is smaller than the rigidity of the reinforced part, resulting in a simple structure and easy implementation.

[0010] In some embodiments, the pressure relief member further includes a main body portion, and the first weak portion connects the main body portion and the reinforcing portion, wherein the rigidity of the first weak portion is less than the rigidity of the main body portion.

[0011] In the above technical solution, the pressure relief member further has a main body portion, and the first weak part is connected between the main body portion and the reinforcing part. The rigidity of the first weak part is set to be smaller than the rigidity of the main body portion. By doing so, the pressure relief member forms a structure in which the rigidity decreases and then increases from the main body portion to the first weak part and then to the reinforcing part. This allows the first weak part to form a buffer area between the main body portion and the reinforcing part that is more easily deformed, further improving the structural strength of the pressure relief member itself and further improving the protective effect of the pressure relief part. This further mitigates the occurrence of phenomena such as deformation or breakage when the battery cell is subjected to internal and external impact forces.

[0012] In some embodiments, the thickness of the first weakened portion is less than the thickness of the body portion.

[0013] In the above technical proposal, the thickness of the first weak portion is set smaller than the thickness of the main body portion, making the first weak portion more easily deformable than the main body portion, thereby realizing that the rigidity of the first weak portion is smaller than the rigidity of the main body portion, resulting in a simple structure and easy implementation.

[0014] In some embodiments, the thickness of the first weakened portion is D1, and the thickness of the main body portion is D2, satisfying 0.3D2≦D1≦0.9D2.

[0015] In the above technical solution, the thickness of the first weak part is set to 0.3 to 0.9 times the thickness of the main body part. This, on the one hand, mitigates the risk of the pressure relief member being relatively weak in overall structural strength and prone to fracture due to the first weak part being too thin, thereby improving the service life and reliability of the pressure relief member; on the other hand, it mitigates the phenomenon where the first weak part is too thick, resulting in the first weak part being less effective in absorbing deformation energy when the battery cell is subjected to internal or external impact forces. This improves the cushioning effect of the first weak part and improves the protective effect of the pressure relief member on the pressure relief part.

[0016] In some embodiments, the first weakened portion has a thickness D1, and the main body has a thickness D2, satisfying 0.5D2≦D1≦0.7D2.

[0017] In the above technical solution, the thickness of the first weak portion is set to 0.5 to 0.7 times the thickness of the main body, which on the one hand further mitigates the risk of the pressure relief member being relatively weak in overall structural strength and prone to fracture due to the first weak portion being too thin, thereby improving the service life and reliability of the pressure relief member and reducing the phenomenon where the first weak portion requires too much material to be removed, optimizing the production tact time and improving the production efficiency of the pressure relief member; on the other hand, it further mitigates the phenomenon where the first weak portion is too thick, reducing the first weak portion's effectiveness in absorbing deformation energy when the battery cell is subjected to internal and external impact forces, and reduces the phenomenon where the first weak portion is too difficult to process.

[0018] In some embodiments, the pressure relief member has a first recessed groove, and the pressure relief member has the first weakened portion in a region where the first recessed groove is provided.

[0019] In the above technical solution, a first groove is provided in the pressure release member, and a first weak portion of the pressure release member is formed in the area where the first groove is provided. A pressure release member employing such a structure is advantageous because it is easy to form the first weak portion in the pressure release member, which reduces the manufacturing difficulty of forming the first weak portion in the pressure release member, and improves the production efficiency of the pressure release member.

[0020] In some embodiments, the first groove has a groove width W, which satisfies 0.5 mm≦W≦10 mm.

[0021] In the above technical solution, by setting the width of the first groove to 0.5mm to 10mm, on the one hand, it is possible to alleviate the phenomenon that the width of the first groove is too small, resulting in the width of the first weak part being too small, which reduces the effectiveness of the first weak part in absorbing deformation energy when the battery cell is deformed due to internal or external impact forces, thereby improving the cushioning effect of the first weak part and improving the protective effect of the pressure relief member on the pressure relief member; on the other hand, it is possible to alleviate the phenomenon that the width of the first groove is too large, resulting in the first weak part occupying too much space in the pressure relief member, which weakens the strength of the overall structure of the pressure relief member, thereby reducing the risk of breakage during use of the pressure relief member.

[0022] In some embodiments, the first groove has a groove width W, which satisfies 2 mm≦W≦5 mm.

[0023] In the above technical solution, the width of the first groove is set to 2mm to 5mm, which, on the one hand, further mitigates the phenomenon that a groove width of the first groove that is too small results in a width of the first weak portion that is too small, thereby reducing the effectiveness of the first weak portion in absorbing deformation energy when the battery cell is deformed due to internal or external impact forces, and also mitigates the phenomenon that a groove width of the first groove that is too small results in the first groove being too difficult to process; on the other hand, it also mitigates the phenomenon that a groove width of the first groove that is too large results in the first weak portion taking up too much space in the pressure relief member, thereby further mitigating the phenomenon that the strength of the overall structure of the pressure relief member is relatively weakened; and it also reduces the processing range of the first groove, optimizes the production cycle time, and thereby improves the production efficiency of the pressure relief member.

[0024] In some embodiments, the first groove is located on a side of the pressure relief member facing the inside of the battery cell.

[0025] In the above technical solution, the first groove on the pressure relief member is located on one side of the pressure relief member facing the inside of the battery cell, thereby reducing the phenomenon of the first groove on the pressure relief member becoming dirty during use.

[0026] In some embodiments, the first groove is located on a side of the pressure relief member that is away from the interior of the battery cell.

[0027] In the above technical proposal, by providing the first groove on the pressure relief member on one side away from the inside of the battery cell of the pressure relief member, it is easy to form the first groove by processing the pressure relief member from the outside, which is advantageous in reducing the difficulty of providing the first groove on the pressure relief member and improving processing efficiency.

[0028] In some embodiments, the first groove is provided on both sides of the pressure relief member.

[0029] In the above technical proposal, by providing a first groove on both sides of the pressure release member, the pressure release member can be thinned from both sides and then the first weak part can be formed. By adopting such a structure, on the one hand, the processing depth for providing the first groove on one side of the pressure release member can be reduced, which is advantageous in that it reduces the difficulty of forming the first weak part in the pressure release member; on the other hand, it is advantageous in that it facilitates the flow of material when processing and forming the first groove, and improves the processing quality of the first groove.

[0030] In some embodiments, a protrusion is formed on one side of the pressure release member away from the first groove and at a position corresponding to the first groove.

[0031] In the above technical solution, a protrusion is formed on one side of the pressure relief member away from the first groove and at a position corresponding to the first groove, so that the first groove can be formed by a pressing process, thereby forming a first weak part in the area corresponding to the first groove of the pressure relief member, which is advantageous in that it is easy to process and form the first weak part and improves processing efficiency.

[0032] In some embodiments, a projection of the protrusion covers a portion of the bottom surface of the first recess along the thickness direction of the first weakened portion.

[0033] In the above technical solution, the projection of the first weak part of the protrusion in the thickness direction covers only the bottom part of the first groove, so that the protrusion and the first groove are misaligned with each other, and the first weak part formed in the area where the first groove of the pressure relief member is provided is made into a stepped structure with different thicknesses, which is advantageous because it allows the first weak part to deform and absorb the internal and external impact forces received by the battery cell.

[0034] In some embodiments, the groove width of the first groove is W, and the size of the portion of the first fragile portion where the protrusion is not formed along the groove width direction of the first groove is L, which satisfies 0.1W≦L≦0.5W.

[0035] In the above technical solution, the size of the portion where the first weak portion forms a protrusion in the groove width direction of the first groove is set to 0.1 to 0.5 of the groove width of the first groove. This, on the one hand, can alleviate the phenomenon where a proportion that is too small results in the area where the first weak portion forms a protrusion being too large, thereby making the first weak portion less effective at absorbing impact forces received from inside and outside the battery cell; and, on the other hand, can alleviate the phenomenon where a proportion that is too large results in too much misalignment between the protrusion and the first groove, thereby making it relatively difficult to press the first groove.

[0036] In some embodiments, the first weakened portion is an annular structure extending circumferentially around the reinforcement portion.

[0037] In the above technical proposal, the first weak part is provided in a ring-shaped structure extending along the circumferential direction of the reinforcing part, so that the first weak part is configured to surround the reinforcing part, thereby enabling the first weak part to absorb impact forces transmitted to the pressure relief member from various directions, which is advantageous in improving the protective effect of the first weak part on the pressure relief member's pressure relief part.

[0038] In some embodiments, the size of the pressure relief member in the first direction is smaller than the size of the pressure relief member in the second direction, and the first direction, the second direction, and the thickness direction of the pressure relief member are perpendicular to each other. The first weak portion is located on at least one side of the reinforcing portion along the first direction.

[0039] In the above technical solution, the size of the pressure release member in the first direction is smaller than the size of the pressure release member in the second direction, so that the pressure release portion of the pressure release member is relatively far from the edge of the pressure release member in the second direction and is relatively less affected by impact forces, and the pressure release portion of the pressure release member is relatively more affected by impact forces in the first direction, so that the first weak portion only needs to be located on one side of the reinforcing portion in the first direction to reduce the impact forces on the pressure release portion of the pressure release member in the first direction, and there is no need to surround the first weak portion outside the entire reinforcing portion, which reduces processing costs and improves the overall structural strength of the pressure release member.

[0040] In some embodiments, the first weakened portion is disposed on both sides of the reinforcement portion along the first direction.

[0041] In the above technical proposal, by installing a first weak part on both sides of the reinforcing part along the first direction, it is possible to install a first weak part on both sides in the direction in which the pressure relief part of the pressure relief member is relatively more affected by impact forces, which is advantageous because it further reduces the impact on the pressure relief part of the pressure relief member when the battery cell is subjected to impact forces from inside or outside.

[0042] In some embodiments, the length of the first weakened portion in the second direction is greater than the size of the pressure relief portion in the second direction.

[0043] In the above technical proposal, by setting the length of the first weak part in the second direction to be larger than the size of the pressure relief part in the second direction, it is possible to effectively block the impact force that the pressure relief part receives in the first direction, thereby improving the protective effect of the first weak part on the pressure relief part.

[0044] In some embodiments, both ends of the first weakened portion extend to both ends of the pressure relief member along the second direction.

[0045] In the above technical proposal, the first weak parts are installed at both ends in the second direction and extend to both ends of the pressure relief member, respectively. This, on the one hand, can further block the pressure relief part from receiving the impact force transmitted from the first direction, thereby further improving the protective effect of the first weak parts on the pressure relief part; and, on the other hand, it is advantageous because it makes it easier to manufacture the first weak parts and reduces the processing difficulty and processing cost of forming the first weak parts in the pressure relief member.

[0046] In some embodiments, a second groove is formed along the thickness direction of the pressure relief member on one side of the pressure relief member away from the inside of the battery cell, and a protrusion is formed on the other side at a position corresponding to the second groove, wherein the groove bottom wall of the second groove includes the pressure relief portion.

[0047] In the above technical solution, a second groove is provided on one side of the pressure relief member away from the inside of the battery cell, and the bottom wall of the second groove includes a pressure relief portion, i.e., the pressure relief portion is formed on the bottom wall of the second groove, so that the second groove can provide a certain protective effect for the pressure relief portion, reduce the phenomenon of the pressure relief portion being worn or damaged by the external environment, and further improve the service life of the pressure relief member.

[0048] In some embodiments, the reinforcing portion is formed surrounding the groove sidewall of the second groove, and the first weak portion is connected to the outside of the reinforcing portion along the radial direction of the reinforcing portion.

[0049] In the above technical proposal, by arranging the reinforcing portion so as to surround the groove side wall of the second groove, i.e., by forming the entire groove side wall of the second groove by the reinforcing portion, the first weak portion and the reinforcing portion are arranged along the radial direction of the reinforcing portion, making it easy to manufacture and process.

[0050] In some embodiments, the pressure relief member further includes a main body, the first weak portion connects the main body and the reinforcing portion, and the stiffness of the first weak portion is less than that of the main body, and a groove sidewall of the second groove includes the first weak portion, and the first weak portion is connected between the main body and the reinforcing portion along the thickness direction of the pressure relief member.

[0051] In the above technical proposal, the groove side wall of the second groove includes a first weak portion, whereby the first weak portion is formed on the groove side wall of the second groove, thereby forming a structure in which the reinforcing portion, the first weak portion and the main body portion are arranged along the thickness direction of the pressure relief member, so that the first weak portion can better absorb the impact force transmitted from the main body portion to the reinforcing portion, which is advantageous because it further improves the protective effect of the first weak portion on the pressure relief portion of the pressure relief member.

[0052] In some embodiments, the pressure relief portion is integrally molded with the reinforcing portion, a notch is provided in the pressure relief member, the pressure relief member forms the pressure relief portion in the area where the notch is provided, and the pressure relief member can tear along the notch when the battery cell releases pressure.

[0053] In the above technical solution, a cut groove is provided in the pressure release member, thereby forming a pressure release section for pressure release in the area where the cut groove is provided on the pressure release member, thereby forming a structure in which the pressure release section and the reinforcing section are integrally molded. A pressure release member employing such a structure is advantageous in that it improves the connection stability between the pressure release section and the reinforcing section, reduces the risk of the pressure release section falling off during use, and effectively improves the stability and reliability of use of the pressure release member.

[0054] In some embodiments, the pressure relief member further includes a second weak portion, the reinforcing portion is connected to the pressure relief portion via the second weak portion, and the thickness of the second weak portion is smaller than the thickness of the reinforcing portion and larger than the thickness of the pressure relief portion.

[0055] In the above technical solution, a second weak part is installed between the pressure relief part and the reinforcing part, and the thickness of the second weak part is smaller than that of the reinforcing part but larger than that of the pressure relief part, so that the thickness decreases sequentially from the reinforcing part to the pressure relief part. On the one hand, this is advantageous because it makes it easier to form a cut groove in the pressure relief member, thereby forming the pressure relief part and reducing the difficulty of processing the cut groove on the pressure relief member; on the other hand, the second weak part can further play a certain buffering effect between the pressure relief part and the reinforcing part, thereby mitigating the phenomenon that stress in the reinforcing part directly acts on the pressure relief part, thereby reducing the risk of cracks or breakage occurring during the use of the pressure relief part, and is advantageous because it improves the stability and reliability of use of the pressure relief part.

[0056] In some embodiments, the pressure relief member has a first surface along a thickness direction of the pressure relief member, and a first groove is provided on the first surface, the cut groove is provided on a groove bottom surface of the first groove, the extension direction of the first groove is the same as the extension direction of the cut groove, and the groove bottom wall of the first groove includes the second weakened portion.

[0057] In the above technical solution, a first groove is provided on the first surface of the pressure relief member, and a cut groove is provided on the bottom surface of the first groove, and the extension direction of the cut groove is aligned with the extension direction of the first groove. That is, the first groove is first provided in the area of ​​the pressure relief member where the cut groove is to be provided, and the cut groove is then provided on the bottom surface of the first groove. This allows the pressure relief member to be thinned in a local area before the cut groove is provided, and the first groove forms a second weakened portion that reduces the thickness, which is easy to implement. A pressure relief member using this structure, on the one hand, can reduce the depth of the cut groove provided on the pressure relief member, reducing the manufacturing difficulty and demand for manufacturing equipment for processing the cut grooves on the pressure relief member, and thus reducing manufacturing costs. On the other hand, it can reduce the molding force that the pressure relief member receives when processing the cut grooves, thereby reducing the risk of cracks occurring in the pressure relief member and improving the production quality of the pressure relief member.

[0058] In some embodiments, the first groove and the cut groove are both annular grooves.

[0059] In the above technical solution, the first groove and the cut groove are both formed in an annular groove structure, so that the pressure relief portion and the second fragile portion are both formed in an annular structure. In a pressure relief member using this structure, on the one hand, the shape of the first groove is the same as the shape of the cut groove, so that the area of ​​the pressure relief member where the cut groove is formed only needs to be locally thinned, which is advantageous because it reduces the difficulty of processing the first groove and reduces the processing range of the first groove; on the other hand, by forming the cut groove in an annular structure, when the pressure relief member releases the internal pressure of the battery cell, the area located inside the cut groove can fall off as a whole after the pressure relief member tears along the cut groove, which is advantageous because it improves the pressure relief area and pressure relief speed of the pressure relief member.

[0060] In some embodiments, the first surface is positioned away from the interior of the battery cell along the thickness direction of the pressure relief member.

[0061] In the above technical solution, the first surface is set as a surface of the pressure relief member that is away from the inside of the battery cell, and the cut groove is set on one side of the pressure relief member that is away from the inside of the battery cell, which is advantageous because it reduces the difficulty of processing the cut groove and makes it easier to process and form the cut groove in the pressure relief member.

[0062] In some embodiments, along the thickness direction of the pressure relief member, the pressure relief member has a second surface opposite to the first surface, and a second groove is provided on the second surface at a position corresponding to the first groove, and the extension direction of the second groove is the same as the extension direction of the first groove.

[0063] In the above technical solution, the pressure relief member further has a second surface opposite to the first surface, and a second groove is provided on the second surface at a position corresponding to the first groove, with the same extension direction as the first groove. This allows the area of ​​the pressure relief member where the cut groove is to be provided to be locally thinned by the first groove and the second groove. On the one hand, the pressure relief member can be thinned from both sides by the first groove and the second groove before the second weak part is formed, which is advantageous in that it is easy to handle and process, and reduces the processing difficulty of forming the second weak part on the pressure relief member. On the other hand, it can improve the shape of the flowable material during the process of forming the cut groove, which is advantageous in that the material generated when forming the cut groove will flow, and improve the structural consistency of the cut groove.

[0064] In some embodiments, the pressure relief portion and the reinforcing portion are installed separately, the pressure relief portion is attached to the reinforcing portion, and a notch is provided on the pressure relief portion, so that the pressure relief portion can tear along the notch when the battery cell releases pressure.

[0065] In the above technical solution, the pressure relief part and the reinforcing part are installed as separate parts, and a notch is provided in the pressure relief part so that the pressure relief part can release the internal pressure of the battery cell after tearing along the notch. This structure is advantageous because it reduces the difficulty of installing the pressure relief part on the pressure relief member, easing the difficulty of manufacturing the pressure relief member, and further improving the production efficiency of the pressure relief member.

[0066] According to a second aspect, an embodiment of the present application further provides a battery cell including the above-mentioned pressure relief member, wherein the pressure relief member is configured to release internal pressure of the battery cell.

[0067] In some embodiments, the battery cell further includes a housing, the housing having a wall, and the pressure relief member is the wall.

[0068] In the above technical solution, the housing has a wall, and the pressure relief member is a wall of the housing, i.e., the pressure relief member is one wall of the housing, so that the first weak part of the pressure relief member can effectively absorb the deformation energy generated by the housing when the battery cell housing is deformed, and protect the pressure relief member.

[0069] In some embodiments, the battery cell further includes a housing, the housing having a wall, the wall having a pressure relief hole, and the pressure relief member is attached to the wall and covers the pressure relief hole.

[0070] In the above technical solution, the housing has a wall, and the pressure relief member is attached to the wall and covers the pressure relief hole in the wall, i.e., the pressure relief member and the housing are installed separately, and the pressure relief member is an independent member attached to one wall of the housing. Adopting such a structure is advantageous for reducing the difficulty of assembling the pressure relief member and the housing and improving the production efficiency of the battery cells.

[0071] In some embodiments, the housing includes a case and end caps, the case having an opening formed therein to define a receiving cavity for receiving an electrode assembly, and the end caps seal the opening. The end caps are the wall portions.

[0072] In the above technical solution, the wall of the housing is set as an end cap for the housing to seal the opening of the case, and therefore, a battery cell adopting this structure is advantageous because it can attach a pressure relief member or form a pressure relief portion and a first weak portion on the end cap, which can effectively reduce the processing difficulty of the battery cell and improve the production efficiency of the battery cell.

[0073] In some embodiments, the housing includes a case and end caps, the case having an interior cavity formed therein with an opening, the cavity being adapted to accommodate an electrode assembly, and the end caps sealing the opening. The case includes the wall portion.

[0074] In the above technical solution, the wall of the housing is installed as one wall of the case. Therefore, a battery cell adopting this structure can reduce the impact on the pressure relief part of the stress generated when the end cap and the case are connected to each other, thereby reducing phenomena such as cracks occurring in the pressure relief part and the first weak part, and further improving the usage stability and service life of the battery cell.

[0075] According to a third aspect, an embodiment of the present application further provides a battery including the battery cell described above.

[0076] According to a fourth aspect, embodiments of the present application further provide a power consuming device including the battery described above. [Brief explanation of the drawings]

[0077] In order to more clearly explain the technical solutions of the embodiments of the present application, the drawings that need to be used in the embodiments are briefly introduced below. It should be understood that the following drawings only illustrate some embodiments of the present application and should not be considered as limiting the scope, and those skilled in the art can obtain other related drawings based on these drawings without any creative efforts.

[0078] [Figure 1] 1 is a structural schematic diagram of a vehicle according to some embodiments of the present application. [Figure 2] 1 is an exploded view of a battery according to some embodiments of the present application. FIG. [Figure 3] 1 is a structural schematic diagram of a battery cell according to some embodiments of the present application; [Figure 4] FIG. 2 is an exploded structural view of a battery cell according to some embodiments of the present application. [Figure 5] 1 is a cross-sectional view of a pressure relief member of a battery cell according to some embodiments of the present application; [Figure 6] 6 is a locally enlarged view of a portion A of the pressure relief member of the battery cell shown in FIG. 5. [Figure 7] 1 is a bottom view of a pressure relief member of a battery cell according to some embodiments of the present application. [Figure 8] 4A and 4B are cross-sectional views of pressure relief members of battery cells according to some other embodiments of the present application. [Figure 9] 9 is a locally enlarged view of a portion B of the pressure relief member of the battery cell shown in FIG. 8. FIG. [Figure 10] 1 is a structural schematic diagram of a battery cell according to some further embodiments of the present application. [Figure 11] 10A and 10B are cross-sectional views of pressure relief members of battery cells according to further some embodiments of the present application. [Figure 12] 12 is a locally enlarged view of a portion C of the pressure relief member of the battery cell shown in FIG. 11. [Figure 13] 10 is a bottom view of another embodiment of a pressure relief member of a battery cell according to some embodiments of the present application. FIG. [Figure 14] 10A and 10B are bottom views of some other embodiments of a pressure relief member of a battery cell according to some embodiments of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0079] In order to clarify the objectives, technical solutions and advantages of the embodiments of the present application, the following will clearly describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some of the embodiments of the present application, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without any creative efforts fall within the scope of protection of the present application.

[0080] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by those skilled in the art of this application, and the terms used in the specification of this application are only for describing specific embodiments and are not intended to limit this application, and the terms "comprises," "has," and any variations thereof in the specification and claims of this application and the above drawings are intended to cover a non-exclusive "comprise." The terms "first," "second," etc. in the specification and claims of this application or the above drawings are not intended to describe a specific order or a hierarchical relationship, but are intended to distinguish different objects.

[0081] An "embodiment" referred to in this application means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of this phrase in various places in the specification do not necessarily all refer to the same embodiment, nor are they mutually exclusive, separate, or alternative embodiments of other embodiments.

[0082] In the description of this application, it should be explained that unless otherwise clearly defined or limited, the terms "attached," "connected," "joined," and "attached" should be understood in a broad sense, and may refer to, for example, a fixed connection, a detachable connection, or an integral connection, a direct connection, an indirect connection via an intermediate medium, or internal communication between two elements. Those skilled in the art can understand the specific meanings of the above terms in this application according to specific circumstances.

[0083] The term "and / or" in this application merely describes the relationship between related objects and indicates that three relationships may exist, for example, A and / or B may represent three cases: A alone, a combination of A and B, and B alone. Also, the character " / " in this application generally indicates that the related objects before and after are in an "or" relationship.

[0084] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments will be omitted. It should be understood that the dimensions such as thickness, aspect, etc. of various components in the embodiments of the present application shown in the drawings, and the dimensions such as thickness, aspect, etc. of the entire integrated device are for illustrative purposes only and do not constitute any limitations on the present application.

[0085] The term "plurality" as used herein refers to two or more (including two).

[0086] In the embodiment of the present application, the battery cell may be a secondary battery, which is a battery cell that can be continuously used by activating the active material in a charging manner after discharging the battery cell.

[0087] The battery cells may be lithium ion batteries, sodium ion batteries, sodium lithium ion batteries, lithium metal batteries, sodium metal batteries, lithium sulfur batteries, magnesium ion batteries, nickel metal hydride batteries, nickel cadmium batteries, lead acid batteries, etc., and the embodiments of the present application are not limited thereto.

[0088] A battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator member. During charging and discharging of the battery cell, active ions (e.g., lithium ions) are absorbed and released by oscillating between the positive electrode and the negative electrode. The separator member, located between the positive electrode and the negative electrode, prevents short-circuiting between the positive and negative electrodes and allows ions to pass through.

[0089] In some embodiments, the positive electrode may be a positive plate, which may include a positive current collector and a positive active material disposed on at least one surface of the positive current collector.

[0090] For example, the positive electrode current collector has two surfaces that face each other in the thickness direction of the positive electrode current collector, and the positive electrode active material is disposed on either one or both of the two facing surfaces of the positive electrode current collector.

[0091] For example, the positive electrode current collector may be a metal foil sheet or a composite current collector. For example, the metal foil sheet may be silver-surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (such as aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, or silver alloy) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, or polyethylene).

[0092] For example, the positive electrode active material may include at least one of a lithium-containing phosphate, a lithium transition metal oxide, and a modified compound thereof. However, the present application is not limited to these materials, and other conventional materials that can be used as a battery positive electrode active material may also be used. These positive electrode active materials may be used alone or in combination of two or more. Here, examples of the lithium-containing phosphate may include, but are not limited to, at least one of lithium iron phosphate (e.g., LiFePO4 (also abbreviated as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (e.g., LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon.

[0093] In some examples, the negative electrode may be a negative electrode plate, and the negative electrode plate may include a negative electrode current collector.

[0094] For example, the negative electrode current collector may be a metal foil sheet, a metal foam, or a composite current collector. For example, the metal foil sheet may be silver-surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium. The metal foam may be nickel foam, copper foam, aluminum foam, alloy foam, or carbon foam. The composite current collector may include a polymeric material base layer and a metal layer. The composite current collector may be formed by forming a metal material (such as copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, or silver alloy) on a polymeric material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, or polyethylene).

[0095] For example, the negative electrode plate may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0096] For example, the negative electrode current collector has two surfaces facing each other in the thickness direction thereof, and the negative electrode active material is disposed on either one or both of the two facing surfaces of the negative electrode current collector.

[0097] For example, the negative electrode active material may be any negative electrode active material known in the art for use in battery cells, and may include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, a silicone-based material, a tin-based material, and lithium titanate.

[0098] In some examples, the material of the positive electrode current collector may be aluminum and the material of the negative electrode current collector may be copper.

[0099] In some embodiments, the electrode assembly further includes a separator member disposed between the positive electrode and the negative electrode.

[0100] In some embodiments, the separator member is a separator. There may be multiple types of separators, and any known porous separator with good chemical stability and mechanical stability may be selected.

[0101] For example, the main material of the separator may be at least one selected from glass fiber, nonwoven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic.

[0102] In some embodiments, the separator member is a solid electrolyte disposed between the positive and negative electrodes, and simultaneously functions to transport ions and separate the positive and negative electrodes.

[0103] In some embodiments, the battery cell further comprises an electrolyte, which serves to conduct ions between the positive and negative electrodes. The electrolyte may be a liquid, gel, or solid.

[0104] In some embodiments, the electrode assembly is a wound structure, and the positive and negative electrode plates are wound into the wound structure.

[0105] In some embodiments, the electrode assembly is a laminate structure.

[0106] In some embodiments, the electrode assembly may have a cylindrical, flattened, or polygonal prism shape, or the like.

[0107] In some embodiments, the electrode assembly is provided with tabs through which current can be drawn from the electrode assembly, including a positive electrode tab and a negative electrode tab.

[0108] In some embodiments, the battery cell may include a housing. The housing may be used to package components such as the electrode assembly and the electrolyte. The housing may be a steel housing, an aluminum housing, a plastic housing (e.g., polypropylene), a composite metal housing (e.g., a copper-aluminum composite housing), an aluminum-plastic film, or the like.

[0109] For example, the battery cells may be cylindrical battery cells, prismatic battery cells, or battery cells of other shapes, where prismatic battery cells include, but are not limited to, rectangular battery cells, blade-shaped battery cells, and polygonal prismatic batteries, and polygonal prismatic batteries include, for example, hexagonal prismatic batteries.

[0110] The battery referred to in the examples of this application refers to a single physical module containing one or more battery cells to provide higher voltage and capacity.

[0111] In some embodiments, the battery may be a battery module, and if there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0112] In some embodiments, the battery may be a battery pack, which includes a housing and battery cells, with the battery cells or modules housed within the housing.

[0113] In some embodiments, the housing may be part of a chassis structure of a vehicle, for example, a portion of the housing may be at least a portion of a floor of the vehicle, or a portion of the housing may be at least a portion of a cross member and a side member of the vehicle.

[0114] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage electrical cabinet, or the like.

[0115] Batteries have outstanding advantages such as high energy density, low environmental pollution, high power density, long service life, wide application range, low self-discharge coefficient, etc., and are currently an important component of the development of new energy. With the rapid development and increasing demand for batteries, the demand for battery service life and reliability is also increasing accordingly.

[0116] In battery technology, to ensure the safety of conventional battery cells, a pressure relief member is generally installed in the battery cell to release the internal pressure of the battery cell, thereby effectively improving the safety of the battery cell. In related technology, the pressure relief member is generally formed on the housing using an integral molding process, i.e., integrated into the battery cell housing, or connected to the housing by welding, fastening, or other methods. When the internal pressure or temperature of the battery cell reaches a threshold, the pressure relief member can be activated and opened to release the internal pressure of the battery cell. However, during use, when the battery cell is subjected to internal or external impact forces, the housing will be deformed, such as an internal impact caused by the expansion of the electrode assembly or an external impact caused by an external collision. This causes the deformation energy of the housing to act directly on the pressure relief member, putting it at risk of deformation or damage. Furthermore, the stability of the pressure relief member is relatively poor, and the pressure relief member is likely to be activated and release pressure prematurely during use, which is detrimental to improving the service life and reliability of the battery cell.

[0117] Based on the above considerations, in order to solve the problems of the relatively short service life and relatively low usage reliability of battery cells, an embodiment of the present application provides a pressure relief member for use in a battery cell, the pressure relief member including a pressure relief portion, a reinforcing portion, and a first weak portion. The pressure relief portion is configured to tear when the battery cell is released from pressure to release the internal pressure of the battery cell. The reinforcing portion is connected to the pressure relief portion and is disposed surrounding the pressure relief portion. The first weak portion is connected to the pressure relief portion via the reinforcing portion, and the rigidity of the first weak portion is less than the rigidity of the reinforcing portion.

[0118] In a battery cell having such a pressure relief member, a pressure relief portion, a reinforcing portion, and a first weak portion are arranged in this order on the pressure relief member, and the reinforcing portion is arranged to surround the pressure relief portion, and the pressure relief portion is connected to the first weak portion via the reinforcing portion. By setting the rigidity of the first weak portion to be smaller than that of the reinforcing portion, the deformation resistance of the first weak portion is made weaker than that of the reinforcing portion, making the first weak portion more susceptible to deformation. This allows the first weak portion to effectively absorb the deformation energy of the battery cell when the battery cell is deformed due to internal or external impact forces. This allows the first weak portion to provide a certain cushioning effect, thereby providing a certain protective effect for the pressure relief portion located inside the reinforcing portion. Furthermore, the pressure relief portion of the pressure relief member can effectively reduce the occurrence of phenomena such as deformation or breakage when the battery cell is subjected to internal or external impact forces. This effectively alleviates the situation where the pressure relief portion of the pressure relief member activates early to relieve pressure during use, improving the usability and service life of the pressure relief member and advantageously improving the service life and usability reliability of the battery cell.

[0119] The pressure relief member disclosed in the embodiments of the present application can be used in, but is not limited to, batteries of power consumption devices such as vehicles, ships, and aircraft, etc. The battery cells and batteries disclosed in the present application can be used to configure the power supply system of the power consumption device, which is advantageous in mitigating the phenomenon of premature opening and pressure relief during use of the battery cells, thereby improving the service life and usage reliability of the battery cells.

[0120] An embodiment of the present application provides a power-consuming device that uses a battery as a power source, and the power-consuming device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a steamship, a spacecraft, etc. Here, the electric toy may include a stationary or mobile electric toy, such as a game console, an electric car toy, an electric steamship toy, and an electric plane toy, and the spacecraft may include an airplane, a rocket, a spacecraft, a spaceship, etc.

[0121] For convenience of explanation, the following embodiment will be described by taking an example in which the power consumption device of one embodiment of the present application is a vehicle 1000.

[0122] Referring to FIG. 1, FIG. 1 is a structural schematic diagram of a vehicle 1000 according to some embodiments of the present application. The vehicle 1000 may be a gasoline-powered vehicle, a gas-powered vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, a range-extender vehicle, etc. A battery 100 is installed inside the vehicle 1000, and the battery 100 may be installed at the bottom, head, or tail of the vehicle 1000. The battery 100 may be used to supply power to the vehicle 1000, for example, the battery 100 may be used as an operating power source for the vehicle 1000. The vehicle 1000 may further include a controller 200 and a motor 300, and the controller 200 is used to control the battery 100 to supply power to the motor 300, for example, to meet operating power consumption needs during startup, navigation, and driving of the vehicle 1000.

[0123] In some embodiments of the present application, the battery 100 can not only be the operating power source for the vehicle 1000, but can also be the driving power source for the vehicle 1000, providing driving power to the vehicle 1000 in place of or in place of fuel oil or natural gas.

[0124] 2 and 3, Fig. 2 is an exploded structural view of a battery 100 according to some embodiments of the present application, and Fig. 3 is a schematic structural view of a battery cell 20 according to some embodiments of the present application. The battery 100 may include a housing 10 and a battery cell 20, and the battery cell 20 is adapted to be housed in the housing 10.

[0125] Here, the housing 10 is used to provide an assembly space for the battery cells 20, and the housing 10 may have various structures. In some embodiments, the housing 10 may include a first housing body 11 and a second housing body 12, where the first housing body 11 and the second housing body 12 are fitted over each other, and the first housing body 11 and the second housing body 12 jointly define an assembly space for accommodating the battery cells 20. The second housing body 12 may have a hollow structure with one end open, or the first housing body 11 may have a plate-like structure, and the first housing body 11 is fitted over the open side of the second housing body 12, whereby the first housing body 11 and the second housing body 12 jointly define the assembly space. Of course, the structure of the housing 10 is not limited thereto, and the first housing body 11 and the second housing body 12 may both have a hollow structure with one end open, and the open side of the first housing body 11 is fitted over the open side of the second housing body 12. Similarly, the housing 10 formed by the first housing body 11 and the second housing body 12 may have various shapes, for example, a cylinder, a rectangular parallelepiped, etc. Illustratively, in FIG. 2, the housing 10 has a rectangular parallelepiped structure.

[0126] Alternatively, the battery 100 may contain one or more battery cells 20 housed within the housing 10. When the housing 10 contains multiple battery cells 20, the multiple battery cells 20 may be connected in series, parallel, or series-parallel, and a series-parallel connection refers to both a series connection and a parallel connection among the multiple battery cells 20. The multiple battery cells 20 may be directly connected in series, parallel, or series-parallel, and an entire module consisting of the multiple battery cells 20 may be housed within the housing 10. Of course, in some embodiments, the battery 100 may be formed by first connecting the multiple battery cells 20 in series, parallel, or series-parallel to form a battery module, and then connecting the multiple battery modules in series, parallel, or series-parallel to form an integrated battery module housed within the housing 10.

[0127] In some embodiments, each battery 100 may further include other structures, for example, the battery 100 may further include bus bar members that are connected to the plurality of battery cells 20 to provide electrical connection between the plurality of battery cells 20.

[0128] Here, each battery cell 20 may be a secondary battery or a primary battery, and may be, but is not limited to, a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery. The battery cells 20 may be cylindrical, flat, rectangular, or have other shapes. For example, in FIG. 3, the battery cells 20 have a rectangular parallelepiped structure.

[0129] Referring to Fig. 3 and further to Fig. 4, Fig. 4 is a structural exploded view of a battery cell 20 according to some embodiments of the present application. The battery cell 20 includes a housing 21 and an electrode assembly 22, and the electrode assembly 22 is housed in the housing 21.

[0130] Here, the housing 21 can also be used to accommodate an electrolyte, for example, an electrolyte solution. The housing 21 may have various structural shapes, for example, a cylindrical body, a rectangular parallelepiped, a prismatic structure, etc. Similarly, the material of the housing 21 may be various materials, for example, copper, iron, aluminum, steel, or an aluminum alloy, etc.

[0131] In some embodiments, the housing 21 may include a case 211 and an end cap 212, where an accommodating cavity is formed inside the case 211, the accommodating cavity is used to accommodate the electrode assembly 22, and the accommodating cavity has an opening 2111, that is, the case 211 is a hollow structure with the opening 2111 at one end, and the end cap 212 is fitted over the opening 2111 of the case 211 to form a sealed connection, thereby forming a sealed space for accommodating the electrode assembly 22 and the electrolyte.

[0132] When assembling the battery cell 20, the electrode assembly 22 may be first placed in the case 211, and the case 211 may be filled with an electrolyte. Then, the end cap 212 may be placed over the opening 2111 of the case 211 to complete the assembly of the battery cell 20.

[0133] The case 211 may have various shapes, such as a cylinder, a rectangular parallelepiped, or a prismatic structure. The shape of the case 211 may be determined based on the specific shape of the electrode assembly 22. For example, if the electrode assembly 22 has a cylindrical structure, a cylindrical case 211 may be selected, and if the electrode assembly 22 has a rectangular parallelepiped structure, a rectangular case 211 may be selected. Of course, the end cap 212 may have a variety of structures. For example, the end cap 212 may have a plate-like structure or a hollow structure with one end open. For example, in FIG. 4, the case 211 has a rectangular parallelepiped structure.

[0134] Of course, it can be understood that the housing 21 is not limited to the above structure, and the housing 21 may have other structures. For example, the housing 21 may include a case 211 and two end caps 212, the case 211 being a hollow structure with openings 2111 on opposite sides, and one end cap 212 correspondingly covering one opening 2111 of the case 211 and forming a sealed connection, thereby forming a sealed space for accommodating the electrode assembly 22 and the electrolyte; that is, the case 211 has openings 2111 on both opposite sides, and the two end caps 212 are respectively covered on opposite sides of the case 211 to seal the corresponding openings 2111.

[0135] It should be noted that the electrode assembly 22 is a component that generates an electrochemical reaction within the battery cell 20. The electrode assembly 22 may have a variety of structures, for example, the electrode assembly 22 may have a wound structure formed by winding a positive electrode plate, a separator member, and a negative electrode plate, or a stacked structure formed by stacking and arranging a positive electrode plate, a separator member, and a negative electrode plate.

[0136] For example, the separator member may be a separator, and the main material of the separator may be at least one selected from glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride.

[0137] Alternatively, the number of electrode assemblies 22 housed in the housing 21 may be one or more. For example, in Fig. 4, two electrode assemblies 22 are installed in the housing 21 of the battery cell 20, and the two electrode assemblies 22 are stacked along the thickness direction of the battery cell 20. Of course, in other embodiments, the number of electrode assemblies 22 housed in the housing 21 may be one, three, four, five, six, seven, or eight, etc.

[0138] In some embodiments, the battery cell 20 may further include an electrode terminal 23, which is insulatedly attached to the housing 21 and electrically connected to the electrode assembly 22 to output or input electrical energy to the battery cell 20.

[0139] It should be noted that the electrode terminal 23 is insulatedly attached to the housing 21, that is, no electrical connection is made between the electrode terminal 23 and the housing 21.

[0140] 3 , the battery cell 20 includes two electrode terminals 23. Accordingly, each electrode assembly 22 has two tabs 221. The polarities of the two tabs 221 are opposite. The two electrode terminals 23 are electrically connected to the two tabs 221 of the electrode assembly 22, respectively, to realize the input or output of the positive and negative electrodes of the battery cell 20. It should be noted that the tabs 221 of the electrode assembly 22 are formed by stacking and connecting regions of positive electrode plates where no positive electrode active material layer is applied, or by stacking and connecting regions of negative electrode plates where no negative electrode active material layer is applied. When the tabs 221 are used to output the positive electrode of the electrode assembly 22, the tabs 221 are formed by stacking and connecting regions of positive electrode plates where no positive electrode active material layer is applied. When the tabs 221 are used to output the negative electrode of the electrode assembly 22, the tabs 221 are formed by stacking and connecting regions of negative electrode plates where no negative electrode active material layer is applied.

[0141] For example, the electrode terminals 23 may be made of a variety of materials, such as copper, iron, aluminum, steel, or an aluminum alloy.

[0142] Optionally, the structure by which the electrode terminals 23 are attached to the housing 21 may be of various types. For example, in FIGS. 3 and 4, both of the two electrode terminals 23 are attached to the end cap 212 of the housing 21. Of course, the structure of the battery cell 20 is not limited thereto, and in other embodiments, both of the two electrode terminals 23 may be attached to the case 211 of the housing 21. Similarly, one of the two electrode terminals 23 may be attached to the case 211 of the housing 21 and the other electrode terminal 23 may be attached to the end cap 212 of the housing 21. In some embodiments, referring to FIG. 3, the battery cell 20 may further include a pressure relief mechanism, which is installed in the housing 21 and is used to release pressure inside the battery cell 20 when the internal pressure or temperature of the battery cell 20 reaches a predetermined value.

[0143] According to some embodiments of the present application, as shown in FIGS. 3 and 4 , the battery cell 20 may further include a pressure relief member 24, which is installed in the housing 21 and configured to release the internal pressure of the battery cell 20 when the internal pressure or temperature of the battery cell 20 reaches a threshold.

[0144] Here, the pressure release member 24 may have a variety of structures, may be a structure installed separately from the housing 21, or may be one wall of the housing 21. When the pressure release member 24 and the housing 21 are installed separately, that is, the housing 21 is provided with a pressure release hole for attaching the pressure release member 24, and the pressure release member 24 is connected to the housing 21 and covers the pressure release hole, the connection method between the pressure release member 24 and the housing 21 may be a variety of methods, such as welding or fastening. Similarly, the pressure release member 24 may be attached to the end cap 212 of the housing 21 or to the case 211 of the housing 21. When the pressure release member 24 is one wall of the housing 21, that is, the pressure release member 24 is integrated into the housing 21 and forms one wall of the housing 21, that is, the pressure release member 24 may be the end cap 212 of the housing 21 or may be one wall of the case 211 of the housing 21.

[0145] For example, in Figures 3 and 4, the pressure relief member 24 is the end cap 212 of the housing 21, that is, the pressure relief member 24 is integrated with the end cap 212, so that the pressure relief member 24 can seal the opening 2111 of the case 211, and the two electrode terminals 23 are both attached to the pressure relief member 24.

[0146] According to some embodiments of the present application, with reference to FIGS. 3 and 4 , and further with reference to FIGS. 5 , 6 and 7 , FIG. 5 is a cross-sectional view of a pressure relief member 24 of a battery cell 20 according to some embodiments of the present application, FIG. 6 is a local enlarged view of portion A of the pressure relief member 24 of the battery cell 20 shown in FIG. 5 , and FIG. 7 is a bottom view of the pressure relief member 24 of the battery cell 20 according to some embodiments of the present application. The present application provides a pressure relief member 24 for use in a battery cell 20, which includes a pressure relief portion 241, a reinforcing portion 242 and a first fragile portion 243. The pressure relief portion 241 is configured to tear when the battery cell 20 is released from pressure, thereby releasing the internal pressure of the battery cell 20. The reinforcing portion 242 is connected to the pressure relief portion 241 and is disposed around the pressure relief portion 241. The first weak portion 243 is connected to the pressure release portion 241 via the reinforcing portion 242 , and the rigidity of the first weak portion 243 is smaller than the rigidity of the reinforcing portion 242 .

[0147] Here, the pressure relief portion 241 of the pressure relief member 24 plays a role in pressure relief, and is broken and torn when the internal pressure or temperature of the battery cell 20 reaches a predetermined value, thereby releasing the pressure inside the battery cell 20. The pressure relief portion 241 and the reinforcing portion 242 may be an integrated structure, that is, the pressure relief portion 241 has a fragile structure formed in the pressure relief member 24 that allows it to tear when the battery cell 20 releases pressure, and the reinforcing portion 242 has a structure that surrounds and is connected to the pressure relief portion 241. Of course, the pressure relief portion 241 and the reinforcing portion 242 may also be separate structures, and the pressure relief portion 241 may be connected to the reinforcing portion 242 by a process such as welding. When the pressure relief portion 241 and the reinforcing portion 242 are separate structures, the pressure relief portion 241 may be a component such as an explosion-proof valve, an explosion-proof sheet, an air valve, a pressure relief valve, or a safety valve.

[0148] The reinforcing part 242 is disposed around the pressure relief part 241 , that is, the reinforcing part 242 has a ring structure with a connected head and tail, and is disposed around the outside of the pressure relief part 241 .

[0149] The first weak portion 243 is connected to the pressure relief portion 241 via the reinforcing portion 242, i.e., the pressure relief portion 241 and the first weak portion 243 are connected via the reinforcing portion 242. Optionally, in FIGS. 5 , 6 and 7 , the pressure relief member 24 may further include a main body portion 245, which is connected to the reinforcing portion 242 via the first weak portion 243, i.e., the edge of the main body portion 245 is at least a part of the edge of the pressure relief member 24. For example, in FIGS. 6 and 7 , the first weak portion 243 has an annular structure, and accordingly, the main body portion 245 has an annular structure that surrounds the first weak portion 243, whereby the edge of the main body portion 245 is the edge of the pressure relief member 24. Of course, in some embodiments, the pressure relief member 24 may not have a main body portion 245, i.e., the first weak portion 243 is installed surrounding the reinforcing portion 242, so that the area located outside the reinforcing portion 242 of the pressure relief member 24 is the first weak portion 243.

[0150] The rigidity of the first weak portion 243 is less than that of the reinforced portion 242. Rigidity refers to the ability of a material or structure to resist elastic deformation when subjected to force, and is a characteristic of the difficulty of a material or structure to elastically deform. That is, the deformation resistance ability of the first weak portion 243 is weaker than that of the reinforced portion 242, and therefore the first weak portion 243 is more likely to deform when subjected to impact than the reinforced portion 242.

[0151] The pressure release member 24 is provided with a pressure release section 241, a reinforcing section 242, and a first weak section 243, which are connected in this order, and the reinforcing section 242 is arranged to surround the pressure release section 241, and the pressure release section 241 is connected to the first weak section 243 via the reinforcing section 242. By setting the rigidity of the first weak section 243 to be smaller than the rigidity of the reinforcing section 242, the deformation resistance of the first weak section 243 is made weaker than that of the reinforcing section 242, making the first weak section 243 more susceptible to deformation. As a result, the first weak section 243 effectively absorbs the deformation energy of the battery cell 20 when the battery cell 20 is deformed due to an internal or external impact force. Therefore, the first fragile part 243 can provide a certain buffering effect, thereby providing a certain protective effect for the pressure relief part 241 located inside the reinforcing part 242. Furthermore, the pressure relief part 241 of the pressure relief member 24 can effectively reduce the occurrence of phenomena such as deformation or breakage when the battery cell 20 is subjected to an internal or external impact force. This effectively mitigates the situation in which the pressure relief part 241 of the pressure relief member 24 operates prematurely to relieve pressure during use, improves the stability and service life of the pressure relief member 24, and is advantageous for improving the service life and reliability of the battery cell 20 equipped with such a pressure relief member 24.

[0152] According to some embodiments of the present application, as shown in FIGS. 5 and 6, the thickness of the first weakened portion 243 is less than the thickness of the reinforcement portion 242.

[0153] Here, the first weak portion 243 and the reinforcing portion 242 are an integrally molded structure, i.e., the material of the first weak portion 243 is the same as the material of the reinforcing portion 242, and thereby the thickness of the first weak portion 243 is set to be smaller than the thickness of the reinforcing portion 242, thereby realizing the first weak portion 243 having a lower rigidity than the reinforcing portion 242. Of course, in other embodiments, the pressure release member 24 may have other structures, for example, the first weak portion 243 and the reinforcing portion 242 are set to be made of different materials, and the strength of the material of the first weak portion 243 is lower than the strength of the material of the reinforcing portion 242, thereby realizing the first weak portion 243 having a lower rigidity than the reinforcing portion 242.

[0154] In FIG. 6, the thickness of the first weak portion 243 is D1, and the thickness of the reinforcement portion 242 is D3. The thickness of the first weak portion 243 is smaller than the thickness of the reinforcement portion 242, i.e., D1 <D3である。

[0155] For example, a first groove 244 is provided in the pressure relief member 24, thereby thinning the area of ​​the pressure relief member 24 where the first groove 244 is formed, thereby forming a first weak portion 243 in the area where the pressure relief member 24 forms the first groove 244. It should be noted that the first groove 244 may be formed by cutting or pressing. For example, in FIG. 6, the first groove 244 is formed by pressing, thereby forming a protrusion 246 on one side of the pressure relief member 24 that is away from the first groove 244. Here, the protrusion 246 may be located directly opposite the first groove 244, that is, the protrusion 246 covers the entire bottom surface of the first groove 244 in the thickness direction of the first weak portion 243. In this embodiment, the first weak portion 243 has a structure that protrudes on one side that is away from the first groove 244 of the pressure relief member 24, and the thickness D1 of the first weak portion 243 is the thickness of the entire bottom wall of the first groove 244. 6, the protrusion 246 may be offset from the first groove 244, i.e., the protrusion 246 covers a portion of the bottom surface of the first groove 244 in the thickness direction of the first weak portion 243. In this embodiment, the first weak portion 243 forms a stepped structure with different thicknesses, so that the first weak portion 243 is formed into two parts connected to each other, one of the two parts has a protrusion, so that this part protrudes toward a side away from the first groove 244 of the pressure relief member 24, and the other part has no protrusion, so that this part does not protrude toward a side away from the first groove 244 of the pressure relief member 24. The thickness D1 of the first weak portion 243 is the thickness of the part of the first weak portion 243 that does not protrude toward a side away from the first groove 244 of the pressure relief member 24.

[0156] By setting the thickness of the first weak portion 243 to be smaller than the thickness of the reinforced portion 242, the first weak portion 243 is made more easily deformable than the reinforced portion 242, thereby realizing that the rigidity of the first weak portion 243 is smaller than the rigidity of the reinforced portion 242, resulting in a simple structure that is easy to realize.

[0157] According to some embodiments of the present application, as shown in Figures 5, 6 and 7, the pressure relief member 24 may further include a main body portion 245, and the first weak portion 243 connects the main body portion 245 and the reinforcing portion 242, and the rigidity of the first weak portion 243 is less than the rigidity of the main body portion 245.

[0158] Here, the rigidity of the first fragile portion 243 is less than the rigidity of the main body portion 245, i.e., the deformation resistance of the first fragile portion 243 is weaker than that of the main body portion 245, and therefore the first fragile portion 243 is more likely to deform when subjected to an impact than the main body portion 245.

[0159] It should be noted that when the pressure relief member 24 is one wall of the housing 21, the main body 245 serves to connect the other walls of the housing 21, so that the pressure relief member 24 and the other walls of the housing 21 surround and form an enclosed space for accommodating the electrode assembly 22; when the pressure relief member 24 and the housing 21 are installed separately and the pressure relief member 24 is an independent member attached to the housing 21, the main body 245 serves to connect the housing 21, so that the pressure relief member 24 is attached to the housing 21.

[0160] The pressure release member 24 further has a main body portion 245, and the first weak portion 243 is connected between the main body portion 245 and the reinforcing portion 242. The rigidity of the first weak portion 243 is set to be smaller than the rigidity of the main body portion 245. This allows the pressure release member 24 to form a structure in which the rigidity decreases and then increases from the main body portion 245 to the first weak portion 243 and then to the reinforcing portion 242. This allows the first weak portion 243 to form a buffer area between the main body portion 245 and the reinforcing portion 242 that is more easily deformed, thereby further improving the structural strength of the pressure release member 24 itself and further improving the protective effect of the pressure release portion 241. This further reduces the occurrence of phenomena such as deformation or breakage when the battery cell 20 is subjected to internal or external impact forces by the pressure release portion 241.

[0161] In some embodiments, as shown in FIGS. 5 and 6, the thickness of first weakened portion 243 is less than the thickness of body portion 245.

[0162] Here, the first weak portion 243 and the main body portion 245 are formed as an integral structure, i.e., the material of the first weak portion 243 is the same as the material of the main body portion 245, and the thickness of the first weak portion 243 is set to be smaller than the thickness of the main body portion 245, thereby realizing the first weak portion 243 having a lower rigidity than the main body portion 245. Of course, in other embodiments, the pressure release member 24 may have other structures, for example, the first weak portion 243 and the main body portion 245 are set to be made of different materials, and the strength of the material of the first weak portion 243 is lower than the strength of the material of the main body portion 245, thereby realizing the first weak portion 243 having a lower rigidity than the main body portion 245.

[0163] In FIG. 6, the thickness of the first weak portion 243 is D1, and the thickness of the main body portion 245 is D2. The thickness of the first weak portion 243 is smaller than the thickness of the main body portion 245, i.e., D1 <D2である。

[0164] By setting the thickness of the first fragile portion 243 to be smaller than the thickness of the main body portion 245, the first fragile portion 243 is made more easily deformable than the main body portion 245, thereby realizing that the rigidity of the first fragile portion 243 is smaller than the rigidity of the main body portion 245, resulting in a simple structure that is easy to realize.

[0165] According to some embodiments of the present application, as shown in FIG. 6, the thickness of the first weakened portion 243 is D1, and the thickness of the main body portion 245 is D2, satisfying 0.3D2≦D1≦0.9D2.

[0166] Here, the thickness of the first fragile portion 243 is D1, i.e., the thickness of the first fragile portion 243 in the depth direction of the first groove 244 is D1. The thickness of the main body 245 is D2, i.e., the thickness of the main body 245 in the thickness direction X of the pressure relief member is D2.

[0167] For example, the thickness D1 of the first weak portion 243 may be 0.3 times, 0.35 times, 0.4 times, 0.45 times, 0.5 times, 0.6 times, 0.7 times, 0.8 times, or 0.9 times the thickness D2 of the main body portion 245.

[0168] By setting the thickness of the first weak portion 243 to 0.3 to 0.9 times the thickness of the main body portion 245, on the one hand, the risk of the pressure relief member 24 being relatively weak in strength and prone to fracture due to the first weak portion 243 being too small in thickness can be mitigated, thereby improving the service life and reliability of the pressure relief member 24; on the other hand, the phenomenon of the first weak portion 243 being less effective in absorbing deformation energy when the battery cell 20 is subjected to internal or external impact forces due to the first weak portion 243 being too large can be mitigated, thereby improving the cushioning effect of the first weak portion 243 and improving the protective effect of the pressure relief member 24 on the pressure relief portion 241.

[0169] In some embodiments, continuing to show FIG. 6, first weakened portion 243 has a thickness D1 and main body portion 245 has a thickness D2, where 0.5D2≦D1≦0.7D2.

[0170] For example, the thickness D1 of the first weak portion 243 may be 0.5 times, 0.52 times, 0.55 times, 0.58 times, 0.6 times, 0.62 times, 0.65 times, 0.7 times, or the like, the thickness D2 of the main body portion 245.

[0171] By setting the thickness of the first weak portion 243 to 0.5 to 0.7 times the thickness of the main body portion 245, on the one hand, the risk of the pressure relief member 24 being relatively weak in strength and prone to fracture due to the first weak portion 243 being too small can be further mitigated, thereby improving the service life and reliability of the pressure relief member 24 and reducing the phenomenon where too much material needs to be removed from the first weak portion 243, optimizing the production takt time and improving the production efficiency of the pressure relief member 24; on the other hand, the phenomenon where the first weak portion 243 is too thick, resulting in the first weak portion 243 being less effective at absorbing deformation energy when the battery cell 20 is subjected to internal and external impact forces, can be further mitigated, thereby reducing the phenomenon where the first weak portion 243 is too difficult to process.

[0172] According to some embodiments of the present application, as shown in Figures 5, 6 and 7, a first groove 244 is provided in the pressure relief member 24, and the pressure relief member 24 forms a first weak portion 243 in the area where the first groove 244 is provided.

[0173] Here, the pressure relief member 24 forms a first fragile portion 243 in the area where the first groove 244 is provided, i.e., the pressure relief member 24 has a reduced thickness in the area where the first groove 244 is formed, so that the portion of the pressure relief member 24 where the first groove 244 is provided is the first fragile portion 243.

[0174] Alternatively, the first groove 244 may be located on one side of the pressure relief member 24 facing the inside of the housing 21, or on one side of the pressure relief member 24 facing away from the inside of the housing 21. Furthermore, the first groove 244 may be formed on both sides of the pressure relief member 24, so that the first grooves 244 located on both sides of the pressure relief member 24 form a first weak portion 243 after the pressure relief member 24 is thinned.

[0175] By providing a first groove 244 in the pressure release member 24, a first weak portion 243 of the pressure release member 24 is formed in the area where the first groove 244 of the pressure release member 24 is provided. A pressure release member 24 employing such a structure is advantageous because it is easy to form the first weak portion 243 in the pressure release member 24, which reduces the manufacturing difficulty of forming the first weak portion 243 in the pressure release member 24 and improves the production efficiency of the pressure release member 24.

[0176] According to some embodiments of the present application, as shown in FIG. 6, the width of the first groove 244 is W, which satisfies 0.5 mm≦W≦10 mm.

[0177] Here, the groove width W of the first groove 244 is the width of the groove bottom surface of the first groove 244 , that is, the width of the first fragile portion 243 .

[0178] For example, the groove width W of the first groove 244 may be 0.5 mm, 0.6 mm, 0.8 mm, 1 mm, 1.5 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, or 10 mm.

[0179] By setting the width of the first groove 244 to 0.5 mm to 10 mm, on the one hand, it is possible to alleviate the phenomenon that the width of the first groove 244 is too small, resulting in the width of the first weak part 243 being too small, which results in the first weak part 243 being less effective at absorbing deformation energy when the battery cell 20 is deformed due to internal or external impact forces, thereby improving the cushioning effect of the first weak part 243 and improving the protective effect of the pressure relief member 24 for the pressure relief part 241; on the other hand, it is possible to alleviate the phenomenon that the width of the first groove 244 is too large, resulting in the first weak part 243 occupying too much space in the pressure relief member 24, which results in the overall structural strength of the pressure relief member 24 being relatively weak, thereby reducing the risk of the pressure relief member 24 breaking during use.

[0180] In some embodiments, as further shown in FIG. 6, the first groove 244 has a groove width W, which satisfies 2 mm≦W≦5 mm.

[0181] For example, the groove width W of the first groove 244 may be 2 mm, 2.2 mm, 2.5 mm, 2.8 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, or 5 mm.

[0182] By setting the width of the first groove 244 to 2 mm to 5 mm, on the one hand, it is possible to alleviate the phenomenon that a groove width of the first groove 244 that is too small results in a width of the first weak portion 243 that is too small, which makes the first weak portion 243 less effective at absorbing deformation energy when the battery cell 20 is deformed due to internal or external impact forces, and that a groove width of the first groove 244 that is too small results in the first groove 244 being too difficult to process; on the other hand, it is possible to alleviate the phenomenon that a groove width of the first groove 244 that is too large results in the first weak portion 243 occupying too much space in the pressure relief member 24, which makes the overall structure of the pressure relief member 24 relatively weak, and it also reduces the processing range of the first groove 244, optimizes the production cycle time, and thereby improves the production efficiency of the pressure relief member 24.

[0183] 5 and 6, and furthermore, FIG. 8 and FIG. 9 show cross-sectional views of pressure relief members 24 of battery cells 20 according to further embodiments of the present application, and FIG. 9 shows enlarged views of a portion B of the pressure relief members 24 of the battery cells 20 shown in FIG. The first groove 244 is disposed on one side of the pressure relief member 24 facing the inside of the battery cells 20.

[0184] Here, the first groove 244 is located on one side of the pressure relief member 24 facing the inside of the battery cell 20, that is, the first groove 244 is located on one side of the pressure relief member 24 facing the internal space of the housing 21.

[0185] By providing the first groove 244 on the pressure relief member 24 on one side of the pressure relief member 24 facing the inside of the battery cell 20, the phenomenon of the first groove 244 on the pressure relief member 24 becoming dirty during use can be reduced.

[0186] 10, 11 and 12, according to some embodiments of the present application, Fig. 10 is a structural schematic diagram of a battery cell 20 according to some other embodiments of the present application, Fig. 11 is a cross-sectional view of a pressure relief member 24 of the battery cell 20 according to some other embodiments of the present application, and Fig. 12 is a local enlarged view of point C of the pressure relief member 24 of the battery cell 20 shown in Fig. 11. The first groove 244 is located on one side of the pressure relief member 24 away from the interior of the battery cell 20.

[0187] Here, the first groove 244 is located on one side of the pressure relief member 24 away from the interior of the battery cell 20, i.e., the first groove 244 is located on one side of the pressure relief member 24 away from the internal space of the housing 21, that is, the first groove 244 is located on one side of the pressure relief member 24 facing the external environment.

[0188] By locating the first groove 244 on the pressure relief member 24 on one side of the pressure relief member 24 away from the inside of the battery cell 20, it is easy to form the first groove 244 by processing the pressure relief member 24 from the outside, which is advantageous in reducing the difficulty of forming the first groove 244 on the pressure relief member 24 and improving processing efficiency.

[0189] Of course, the structure of the pressure relief member 24 is not limited to this, and in some embodiments, the first groove 244 is provided on both sides of the pressure relief member 24 .

[0190] Here, the two first grooves 244 provided on both sides of the pressure release member 24 are provided corresponding to the thickness direction X of the pressure release member, and the first fragile portion 243 can be formed after the two first grooves 244 are thinned from both sides of the pressure release member 24.

[0191] By providing the first grooves 244 on both sides of the pressure release member 24, the pressure release member 24 can be thinned from both sides before the first weak portion 243 is formed. By adopting this structure, on the one hand, the processing depth for providing the first grooves 244 on one side of the pressure release member 24 can be reduced, which is advantageous because it reduces the difficulty of forming the first weak portion 243 in the pressure release member 24; on the other hand, it is advantageous because it facilitates the flow of material when processing and forming the first grooves 244, and improves the processing quality of the first grooves 244.

[0192] According to some embodiments of the present application, as shown in FIGS. 5 and 6, a protrusion 246 is formed on one side of the pressure relief member 24 away from the first groove 244 and at a position corresponding to the first groove 244.

[0193] Here, a protrusion 246 is formed on one side away from the first groove 244 of the pressure release member 24 and at a position corresponding to the first groove 244, i.e., at least a portion of the first fragile portion 243 formed in the area where the first groove 244 of the pressure release member 24 is provided protrudes on one side away from the first groove 244 of the pressure release member 24.

[0194] By forming a protrusion 246 on one side away from the first groove 244 of the pressure relief member 24 and at a position corresponding to the first groove 244, the first groove 244 can be formed by a pressing process, thereby forming a first weak portion 243 in the area corresponding to the first groove 244 of the pressure relief member 24, which is advantageous in that it is easy to process and form the first weak portion 243 and improves processing efficiency.

[0195] In some embodiments, the projection of the protrusion 246 covers a portion of the bottom surface of the first recessed groove 244 along the thickness direction of the first weakened portion 243 .

[0196] Here, in Figure 6, the reinforcing portion 242, the first weak portion 243 and the main body portion 245 are structured to be arranged along the radial direction of the reinforcing portion 242, i.e., the thickness direction of the first weak portion 243 is the thickness direction X of the pressure relief member.

[0197] The projection of the protrusion 246 covers a portion of the bottom surface of the first groove 244, i.e., the protrusion 246 and the first groove 244 are offset from each other, so that the first weak portion 243 has a stepped structure with different thicknesses. For example, in FIG. 6 , a portion of the protrusion 246 is located corresponding to the first groove 244 in the thickness direction of the pressure relief member, and the other portion is connected to the reinforcing portion 242. Here, the portion of the protrusion 246 located corresponding to the first groove 244 forms the first weak portion 243, so that the first weak portion 243 has a stepped structure with different thicknesses, so that the protrusion 246 is located at the portion of the first weak portion 243 and not at the other portion.

[0198] It should be noted that in FIG. 6 , the first groove 244 is located on one side of the pressure relief member 24 facing the inside of the housing 21, and the reinforcing portion 242, the first fragile portion 243 and the main body portion 245 are arranged along the radial direction of the reinforcing portion 242, and the protrusion 246 formed on one side of the pressure relief member 24 away from the first groove 244 can further be used to attach a patch, thereby playing a role in protecting the pressure relief member 241.

[0199] The projection of the protrusion 246 onto the first fragile portion 243 in the thickness direction covers only the bottom surface of the first groove 244, thereby causing the protrusion 246 and the first groove 244 to be misaligned with each other, and giving the first fragile portion 243 formed in the area where the first groove 244 of the pressure relief member 24 is provided a stepped structure with different thicknesses, which is advantageous because it allows the first fragile portion 243 to deform and absorb internal and external impact forces received by the battery cell 20.

[0200] In some embodiments, as shown in FIG. 6 , the groove width of the first groove 244 is W, and the size of the portion of the first fragile portion 243 along the groove width direction of the first groove 244 where the protrusion 246 is not formed is L, which satisfies 0.1W≦L≦0.5W.

[0201] Here, the size of the part of the first fragile portion 243 where the protrusion 246 is not formed is L, that is, the size in the groove width direction of the first groove 244 in the part where the thickness of the first fragile portion 243 of the step structure is relatively small is L.

[0202] 0.1W≦L≦0.5W, i.e., no protrusion 246 is formed on the first weak portion 243, and the relatively thin portion of the first weak portion 243 with a stepped structure accounts for 10% to 50% of the groove width of the first groove 244, i.e., the area where the projection of the protrusion 246 in the thickness direction of the first weak portion 243 covers the bottom surface of the first groove 244 accounts for 50% to 90% of the groove width of the first groove 244 at the bottom surface of the first groove 244.

[0203] By setting the size of the portion of first weak portion 243 in the groove width direction of first groove 244 where protrusion 246 is formed to 0.1 to 0.5 of the groove width of first groove 244, on the one hand, it is possible to alleviate the phenomenon where, if the ratio is too small, the area where protrusion 246 is formed of first weak portion 243 is too large, making the first weak portion 243 relatively poor at absorbing impact forces received from inside and outside of battery cell 20; on the other hand, it is possible to alleviate the phenomenon where, if the ratio is too large, the misalignment between protrusion 246 and first groove 244 is too large, making it relatively difficult to press first groove 244.

[0204] According to some embodiments of the present application, as shown in FIGS. 5, 6 and 7, the first weakened portion 243 is an annular structure extending along the circumferential direction of the reinforcing portion 242.

[0205] Here, the first weak portion 243 has a ring-shaped structure extending along the circumferential direction of the reinforcement portion 242, i.e., the first weak portion 243 has a ring-shaped structure connected at its head and tail, and extends along the circumferential direction of the reinforcement portion 242, so that the first weak portion 243 has a structure that is installed around the reinforcement portion 242.

[0206] Optionally, in FIG. 7, the pressure relief portion 241 has an elliptical ring structure, whereby the reinforcing portion 242 has an elliptical structure arranged surrounding the pressure relief portion 241, wherein the size of the reinforcing portion 242 in the first direction Y is smaller than the size of the reinforcing portion 242 in the second direction Z, whereby the reinforcing portion 242 has two strip-shaped segments 2421 arranged opposite to each other in the first direction Y and two arc-shaped segments 2422 arranged opposite to each other in the second direction Z, and the two arc-shaped segments 2422 are respectively connected to both ends of the strip-shaped segment 2421 in the first direction Y, and the first direction Y, the second direction Z and the thickness direction X of the pressure relief member are perpendicular to each other.

[0207] For example, in Figures 5 and 7, there is one first weak portion 243, but of course, in some embodiments, there may be multiple first weak portions 243, and the multiple first weak portions 243 are structured to be arranged in a surrounding manner in sequence, that is, one first weak portion 243 is arranged to surround the outside of another first weak portion 243, and each adjacent two first weak portions 243 are connected via a connecting portion.

[0208] Optionally, in FIG. 7, the first weak portion 243 has a structure having a uniform width and a uniform thickness in its extension direction; of course, in other embodiments, the first weak portion 243 may be configured to have a structure having a non-uniform thickness in its extension direction; for example, the thickness of the region connected to the strip segment 2421 of the reinforcement portion 242 of the first weak portion 243 may be smaller than the thickness of the region connected to the first weak portion 243 and the arc segment 2422 of the reinforcement portion 242; and the thickness of the region connected to the strip segment 2421 of the reinforcement portion 242 of the first weak portion 243 may be larger than the thickness of the region connected to the first weak portion 243 and the arc segment 2422 of the reinforcement portion 242. Similarly, the first weak portion 243 may further be arranged in a structure having an uneven width in its extension direction. For example, refer to FIG. 13, which is a bottom view of another embodiment of the pressure relief member 24 of the battery cell 20 according to some embodiments of the present application, in which the width in the second direction Z of the region where the first weak portion 243 is connected to the arc segment 2422 is larger than the width in the first direction Y of the region where the first weak portion 243 is connected to the strip segment 2421. That is, in a structure in which the pressure relief portion 241 is formed in the region where the first groove 244 is provided in the pressure relief member 24, the groove width of the portion where the first groove 244 is connected to the arc segment 2422 is larger than the groove width of the portion where the first groove 244 is connected to the strip segment 2421. Of course, the pressure relief member 24 may have other structures. For example, refer to FIG. 14, which is a bottom view of some other embodiments of the pressure relief member 24 of the battery cell 20 according to some embodiments of the present application, in which the width in the first direction Y of the region where the first weak portion 243 and the strip-shaped segment 2421 are connected is larger than the width in the second direction Z of the region where the first weak portion 243 and the arc segment 2422 are connected. In other words, in a structure in which the pressure relief member 241 is formed in the region where the first groove 244 is provided in the pressure relief member 24, the groove width of the portion where the first groove 244 and the strip-shaped segment 2421 are connected is larger than the groove width of the portion where the first groove 244 and the arc segment 2422 are connected.

[0209] By providing the first weak portion 243 in a ring-shaped structure extending along the circumferential direction of the reinforcing portion 242, the first weak portion 243 is structured to be installed surrounding the reinforcing portion 242, which is advantageous because it enables the pressure relief member 24 to absorb impact forces transmitted from various directions, thereby improving the protective effect of the first weak portion 243 on the pressure relief portion 241 of the pressure relief member 24.

[0210] 10, 11 and 12, the size of the pressure relief member 24 in the first direction Y is smaller than the size of the pressure relief member 24 in the second direction Z, and the first direction Y, the second direction Z and the thickness direction X of the pressure relief member are perpendicular to each other. A first weak portion 243 is provided on at least one side of the reinforcing portion 242 along the first direction Y.

[0211] 10 , the pressure relief member 24 is one wall on the case 211 of the housing 21, and is connected to the wall at the largest surface of the case 211 and the wall where the case 211 and the end cap 212 face each other. As a result, the pressure relief member 24 is one side wall of the case 211 in the longitudinal direction of the battery cell 20. As a result, the first direction Y is the thickness direction of the battery cell 20, and the second direction Z is the height direction of the battery cell 20. The wall at the largest surface of the case 211 is more susceptible to deformation during use. Therefore, by adopting this structure, the deformation energy of the case 211 can be effectively absorbed by the first weak part 243, and the impact of the deformation of the case 211 on the pressure relief member 241 can be reduced. Of course, in other embodiments, the pressure relief member 24 may be the bottom wall where the case 211 and the end cap 212 face each other, or the wall at the largest surface of the case 211.

[0212] Optionally, the first weak portion 243 is a strip-shaped structure extending along the second direction Z, and of course, in other embodiments, the first weak portion 243 may be an arc-shaped structure, etc., located on one side of the reinforcing portion 242 in the first direction Y.

[0213] The size of the pressure release member 24 in the first direction Y is smaller than the size of the pressure release member 24 in the second direction Z, so that the pressure release portion 241 of the pressure release member 24 is relatively far from the edge of the pressure release member 24 in the second direction Z and is relatively less affected by the impact force it receives, and the pressure release portion 241 of the pressure release member 24 is relatively more affected by the impact force it receives in the first direction Y. Therefore, it is only necessary to install the first weak portion 243 so that it is located on one side of the reinforcing portion 242 in the first direction Y, to reduce the effect of the impact force that the pressure release portion 241 of the pressure release member 24 receives in the first direction Y. Furthermore, there is no need to install the first weak portion 243 around and outside the entire reinforcing portion 242, which is advantageous in reducing processing costs and improving the overall structural strength of the pressure release member 24.

[0214] In some embodiments, the first weak portions 243 are provided on both sides of the reinforcing portion 242 along the first direction Y. That is, the pressure release member 24 has two first weak portions 243, each located on both sides of the reinforcing portion 242 in the first direction Y.

[0215] For example, in Figure 10, only one first weak portion 243 is installed on one side of the reinforcement portion 242 in the first direction Y, but of course, in some embodiments, there may be multiple first weak portions 243 installed on one side of the reinforcement portion 242 in the first direction Y, and the multiple first weak portions 243 are arranged at intervals along the first direction Y, and each adjacent two first weak portions 243 in the multiple first weak portions 243 located on the same side of the reinforcement portion 242 in the first direction Y are connected via a connecting portion.

[0216] By providing the first weak portions 243 on both sides of the reinforcing portion 242 along the first direction Y, the first weak portions 243 are provided on both sides in the direction in which the pressure relief portion 241 of the pressure relief member 24 is relatively more susceptible to impact forces, which is advantageous in further reducing the impact on the pressure relief portion 241 of the pressure relief member 24 when the battery cell 20 is subjected to internal or external impact forces.

[0217] According to some embodiments of the present application, as shown in Fig. 10, the length of the first weak portion 243 in the second direction Z is greater than the size of the pressure relief portion 241 in the second direction Z. That is, the length of the first weak portion 243 extending in the second direction Z is greater than the spatial size of the pressure relief portion 241 in the second direction Z.

[0218] By setting the length of the first fragile portion 243 in the second direction Z to be larger than the size of the pressure relief portion 241 in the second direction Z, the impact force that the pressure relief portion 241 receives in the first direction Y can be effectively blocked, thereby improving the protective effect of the first fragile portion 243 on the pressure relief portion 241.

[0219] In some embodiments, along the second direction Z, both ends of the first weakened portion 243 extend to both ends of the pressure relief member 24, respectively.

[0220] For example, the first weak portion 243 has a structure formed in the area where the first groove 244 is provided in the pressure relief member 24, and both ends of the first weak portion 243 extend to both ends of the pressure relief member 24 along the second direction Z, that is, the first groove 244 extends along the second direction Z, and both ends of the first groove 244 in the second direction Z respectively penetrate both ends of the pressure relief member 24, which makes it easier to process the first groove 244 and is advantageous in reducing the difficulty of material flow when the pressure relief member 24 processes the first groove 244.

[0221] By installing the first weak portion 243 at both ends in the second direction Z and extending it to both ends of the pressure relief member 24, on the one hand, the pressure relief portion 241 can be further isolated from the impact force transmitted from the first direction Y, thereby further improving the protective effect of the first weak portion 243 on the pressure relief portion 241; on the other hand, it is advantageous because it makes it easier to manufacture the first weak portion 243 and reduces the processing difficulty and processing cost of forming the first weak portion 243 in the pressure relief member 24.

[0222] According to some embodiments of the present application, as shown in FIGS. 5 and 6 , a second groove 247 is formed on one side of the pressure relief member 24 that is away from the inside of the battery cell 20 along the thickness direction X of the pressure relief member, and a protrusion 248 is formed on the other side at a position corresponding to the second groove 247, and the groove bottom wall of the second groove 247 includes a pressure relief portion 241.

[0223] Here, a second groove 247 is formed on one side of the pressure relief member 24 away from the inside of the battery cell 20, and a protrusion 248 is formed on the other side at a position corresponding to the second groove 247. This structure of the second groove 247 is formed by a press process, which is easy to process and advantageous for improving the processing efficiency of providing the second groove 247 in the pressure relief member 24.

[0224] The bottom wall of the second groove 247 includes a pressure relief portion 241, i.e., the pressure relief portion 241 forms at least a part of the bottom wall of the second groove 247. It should be noted that when the pressure relief portion 241 and the reinforcing portion 242 are an integral structure, i.e., when the pressure relief member 24 is manufactured by an integral molding process, the pressure relief portion 241 is located on the bottom wall of the second groove 247; when the pressure relief portion 241 and the reinforcing portion 242 are separate structures, i.e., when the pressure relief member 24 has a structure in which the pressure relief portion 241 and the reinforcing portion 242 are separately installed and the pressure relief portion 241 is attached to the reinforcing portion 242 by a process such as welding, the pressure relief portion 241 is located on the bottom wall of the second groove 247. For example, in FIG. 6, the pressure relief portion 241 and the reinforcing portion 242 are an integrated structure, that is, the pressure relief portion 241 is provided on the bottom wall of the second groove 247, a notch 249 is provided on the bottom wall of the second groove 247, and the pressure relief member 24 forms the pressure relief portion 241 in the area where the notch 249 is provided.

[0225] A second groove 247 is provided on one side of the pressure relief member 24 facing away from the interior of the battery cell 20, and the bottom wall of the second groove 247 includes a pressure relief portion 241, i.e., the pressure relief portion 241 is formed on the bottom wall of the second groove 247, so that the second groove 247 can provide a certain protective effect for the pressure relief portion 241, thereby reducing the phenomenon of the pressure relief portion 241 being worn or damaged by the external environment, and further improving the service life of the pressure relief member 24.

[0226] According to some embodiments of the present application, as still shown in Figures 5 and 6, the reinforcing portion 242 is formed by surrounding the groove side wall of the second groove 247, and the first weak portion 243 is connected to the outside of the reinforcing portion 242 along the radial direction of the reinforcing portion 242.

[0227] Here, the reinforcing portion 242 surrounds and forms the groove side wall of the second groove 247, i.e., the groove side wall of the second groove 247 is formed by the reinforcing portion 242, that is, the groove side wall of the second groove 247 is at least a part of the reinforcing portion 242.

[0228] Along the radial direction of the reinforcing portion 242, the first weak portion 243 is connected to the outside of the reinforcing portion 242, i.e., the pressure relief portion 241 is installed inside the reinforcing portion 242, and the first weak portion 243 is installed outside the reinforcing portion 242, thereby forming a structure in which the reinforcing portion 242, the first weak portion 243, and the main body portion 245 are arranged in order along the radial direction of the reinforcing portion 242.

[0229] It should be noted that in an embodiment in which the first weak portion 243 is connected to the outside of the reinforcing portion 242 along the radial direction of the reinforcing portion 242, the first weak portion 243 may be a ring-shaped structure, i.e., the first weak portion 243 surrounds the outside of the reinforcing portion 242; of course, the first weak portion 243 may be a band-shaped structure, i.e., the first weak portion 243 is located on one side of the reinforcing portion 242 along the radial direction of the reinforcing portion 242.

[0230] By forming the reinforcing portion 242 so as to surround the groove side wall of the second groove 247, the first fragile portion 243 and the reinforcing portion 242 are arranged along the radial direction of the reinforcing portion 242, which is easy to manufacture and process.

[0231] According to some embodiments of the present application, as shown in Figures 8 and 9, the pressure relief member 24 may further include a main body portion 245, a first weak portion 243 connecting the main body portion 245 and the reinforcing portion 242, and the rigidity of the first weak portion 243 is less than that of the main body portion 245, and the groove side wall of the second groove 247 includes the first weak portion 243, and the first weak portion 243 is connected between the main body portion 245 and the reinforcing portion 242 along the thickness direction X of the pressure relief member.

[0232] Here, the groove sidewall of the second groove 247 includes a first weakened portion 243, i.e., the first weakened portion 243 is formed on the groove sidewall of the second groove 247, so that the first weakened portion 243 is at least a part of the groove sidewall of the second groove 247. In a structural embodiment in which the first weakened portion 243 is formed in the region where the first groove 244 is provided on the pressure release member 24, the first groove 244 is provided on one side of the groove sidewall of the second groove 247, and the first groove 244 may be provided on one side of the groove sidewall of the second groove 247 facing the second groove 247, or on one side of the groove sidewall of the second groove 247 facing away from the second groove 247. For example, the first groove 244 is provided on one side of the groove sidewall of the second groove 247 facing away from the second groove 247.

[0233] Along the thickness direction X of the pressure release member, the first weak portion 243 is connected between the main body portion 245 and the reinforcing portion 242, i.e., the pressure release portion 241 and the main body portion 245 are arranged at intervals along the thickness direction X of the pressure release member, so that the reinforcing portion 242, the first weak portion 243 and the main body portion 245 are arranged in order along the thickness direction X of the pressure release member.

[0234] It should be noted that in FIG. 9 , the first fragile portion 243 is formed on the side wall of the second groove 247. In this embodiment, a protrusion 255 may be provided on one side of the main body 245 that is away from the interior of the battery cell 20. The protrusion 255 has a ring-shaped structure that surrounds the pressure relief portion 241 and forms an attachment space for attaching a protective patch, thereby serving to protect the pressure relief portion 241.

[0235] The groove side wall of the second groove 247 includes a first weak portion 243, so that the first weak portion 243 is formed on the groove side wall of the second groove 247, so that the reinforcing portion 242, the first weak portion 243 and the main body portion 245 are arranged along the thickness direction X of the pressure relief member, so that the first weak portion 243 can better absorb the impact force transmitted by the main body portion 245 to the reinforcing portion 242, which is advantageous because it further improves the protective effect of the first weak portion 243 on the pressure relief portion 241 of the pressure relief member 24.

[0236] According to some embodiments of the present application, as shown in FIGS. 5 and 6 , the pressure relief portion 241 is integrally molded with the reinforcing portion 242, and a notch 249 is provided on the pressure relief member 24, and the pressure relief member 24 forms the pressure relief portion 241 in the area where the notch 249 is provided, so that the pressure relief member 24 can tear along the notch 249 when the battery cell 20 is released from the pressure.

[0237] Here, the pressure relief portion 241 is integrally molded with the reinforcing portion 242, that is, the pressure relief member 24 has a structure formed by an integral molding process, so that the pressure relief portion 241 and the reinforcing portion 242 are formed in the pressure relief member 24 as an integral structure.

[0238] The pressure relief member 24 forms a pressure relief portion 241 in the area where the cutout groove 249 is provided, that is, the pressure relief member 24 forms a fragile structure at the position where the cutout groove 249 is provided, and this fragile structure is the pressure relief portion 241 for releasing pressure when the pressure relief member 24 is used to release the internal pressure of the battery cell 20. When the battery cell 20 releases the internal pressure using the pressure relief member 24, the pressure relief member 24 can tear along the cutout groove 249, thereby breaking the pressure relief portion 241 and thereby releasing the internal pressure of the battery cell 20. Of course, the structure of the pressure relief portion 241 is not limited to this, and in other embodiments, the pressure relief portion 241 can have other structures. For example, a fragile region can be formed in the pressure relief member 24 by punching, and the fragile region can be broken when the battery cell 20 releases pressure, thereby releasing the internal pressure of the battery cell 20, and this fragile region is the pressure relief portion 241.

[0239] By providing a cut groove 249 in the pressure release member 24, a pressure release section 241 for releasing pressure is formed in the area on the pressure release member 24 where the cut groove 249 is provided, thereby forming a structure in which the pressure release section 241 and the reinforcing section 242 are integrally molded. A pressure release member 24 employing such a structure is advantageous because it improves the connection stability between the pressure release section 241 and the reinforcing section 242, reduces the risk of the pressure release section 241 falling off during use, and further effectively improves the stability and reliability of use of the pressure release member 24.

[0240] According to some embodiments of the present application, as shown in FIG. 6 , the pressure relief member 24 may further include a second weak portion 250, and the reinforcing portion 242 is connected to the pressure relief portion 241 through the second weak portion 250, and the thickness of the second weak portion 250 is smaller than the thickness of the reinforcing portion 242 and larger than the thickness of the pressure relief portion 241.

[0241] Here, the reinforcing portion 242 is connected to the pressure relief portion 241 via the second weakened portion 250, i.e., the pressure relief member 24 further has a second weakened portion 250 between the area where the cutout groove 249 and the pressure relief portion 241 are formed and the reinforcing portion 242, the second weakened portion 250 being smaller in thickness than the reinforcing portion 242 but larger in thickness than the pressure relief portion 241. Of course, in some embodiments, the pressure relief member 24 does not need to have the second weakened portion 250, i.e., the pressure relief member 24 is directly connected to the reinforcing portion 242 in the area where the cutout groove 249 and the pressure relief portion 241 are formed.

[0242] A second weak portion 250 is disposed between the pressure relief portion 241 and the reinforcing portion 242, and the thickness of the second weak portion 250 is smaller than that of the reinforcing portion 242 but larger than that of the pressure relief portion 241. This results in a structure in which the thickness decreases sequentially from the reinforcing portion 242 to the pressure relief portion 241. On the one hand, this is advantageous because it makes it easier to form the cutouts 249 in the pressure relief member 24, thereby forming the pressure relief portion 241 and reducing the difficulty of processing the cutouts 249 on the pressure relief member 24. On the other hand, the second weak portion 250 can further provide a certain buffering effect between the pressure relief portion 241 and the reinforcing portion 242, thereby mitigating the phenomenon in which the stress in the reinforcing portion 242 directly acts on the pressure relief portion 241. This is advantageous because it reduces the risk of cracks or breakage occurring in the pressure relief portion 241 during use, thereby improving the stability and reliability of use of the pressure relief portion 241.

[0243] According to some embodiments of the present application, as shown in FIGS. 5 and 6 , along the thickness direction X of the pressure relief member, the pressure relief member 24 has a first surface 251, a first groove 252 is provided on the first surface 251, a cut groove 249 is provided on the groove bottom surface of the first groove 252, the extension direction of the first groove 252 is the same as the extension direction of the cut groove 249, and the groove bottom wall of the first groove 252 includes a second fragile portion 250.

[0244] Here, the first surface 251 may be a surface on which the pressure relief member 24 is installed facing the inside of the housing 21, or a surface on which the pressure relief member 24 is installed away from the inside of the housing 21. For example, in FIG. 5 , the first surface 251 is installed away from the inside of the housing 21, that is, the first surface 251 is a surface on which the pressure relief member 24 is installed away from the electrode assembly 22 of the battery cell 20.

[0245] A first groove 252 is formed on the first surface 251, and a notched groove 249 is formed on the bottom surface of the first groove 252. That is, the first groove 252 is first formed on the first surface 251, and then the notched groove 249 is formed on the bottom surface of the first groove 252. As a result, the first groove 252 and the notched groove 249 are arranged along the thickness direction X of the pressure relief member.

[0246] The extension direction of the first groove 252 is the same as the extension direction of the cut groove 249, that is, the shape of the first groove 252 is the same as the shape of the cut groove 249, and the structure is such that a multi-stage step groove is formed on the first surface 251, and the multi-stage step groove includes the first groove 252 and the cut groove 249 arranged in sequence along the thickness direction X of the pressure relief member.

[0247] The bottom wall of the first groove 252 includes a second weak portion 250, i.e., the second weak portion 250 is the area where the first groove 252 is provided in the pressure relief member 24, and is structured to be connected between the pressure relief portion 241 and the reinforcing portion 242, i.e., the area where the cut groove 249 is not provided in the bottom wall of the first groove 252, and the area located between the cut groove 249 and the reinforcing portion 242 is the second weak portion 250.

[0248] The pressure relief member 24 has a first groove 252 formed on a first surface 251 thereof, and a notched groove 249 formed on the bottom surface of the first groove 252, with the extension direction of the notched groove 249 being aligned with the extension direction of the first groove 252. That is, the pressure relief member 24 has a region where the notched groove 249 is to be formed, where the first groove 252 is first formed with the same extension direction as the notched groove 249, and the notched groove 249 is formed on the bottom surface of the first groove 252, whereby the pressure relief member 24 can be thinned in a local region before the notched groove 249 is formed. The second weak part 250 can be formed to have a thinner thickness, which is easy to realize. The pressure relief member 24 adopting such a structure is advantageous in that, on the one hand, it can reduce the depth of the cut groove 249 in the pressure relief member 24, reducing the manufacturing difficulty of machining the cut groove 249 in the pressure relief member 24 and the demand for manufacturing equipment, thereby reducing manufacturing costs; on the other hand, it can reduce the molding force that the pressure relief member 24 receives when machining the cut groove 249, reducing the risk of cracks occurring in the pressure relief member 24 and improving the production quality of the pressure relief member 24.

[0249] 4, 5 and 6, the first groove 252 and the cut groove 249 are both annular grooves. That is, the first groove 252 and the cut groove 249 are connected to each other in an annular structure, thereby forming an annular pressure relief portion 241 on the pressure relief member 24. In actual manufacturing, the annular first groove 252 is first formed on the pressure relief member 24, and then the cut groove 249 is formed on the bottom surface of the first groove 252, thereby forming the pressure relief portion 241 at the position where the cut groove 249 is located on the pressure relief member 24.

[0250] It should be noted that the structures of the first groove 252 and the notched groove 249 are not limited thereto, and in other embodiments, the first groove 252 and the notched groove 249 may have other structures, for example, the first groove 252 and the notched groove 249 may both have a strip-shaped structure, an arc-shaped structure, a triangular structure, a rectangular structure, or a pentagonal structure, etc. Of course, in some embodiments, the first groove 252 and the notched groove 249 may both have an "H"-shaped structure, a "V"-shaped structure, or an "X"-shaped structure, etc.

[0251] The first groove 252 and the notched groove 249 are both formed in an annular groove structure, so that the pressure relief portion 241 and the second fragile portion 250 both have an annular structure. In the pressure relief member 24 employing this structure, on the one hand, the shape of the first groove 252 is the same as the shape of the notched groove 249, so that the area of ​​the pressure relief member 24 where the notched groove 249 is formed only needs to be locally thinned, which is advantageous because it makes the processing of the first groove 252 easier and reduces the processing area of ​​the first groove 252; on the other hand, the notched groove 249 has an annular structure, so that when the pressure relief member 24 releases the internal pressure of the battery cell 20, the area inside the notched groove 249 can be entirely detached after the pressure relief member 24 tears along the notched groove 249, which is advantageous because it improves the pressure relief area and pressure relief speed of the pressure relief member 24.

[0252] According to some embodiments of the present application, as shown in FIGS. 5 and 6, the first surface 251 is disposed away from the interior of the battery cell 20 along the thickness direction X of the pressure relief member.

[0253] Here, the first surface 251 is disposed away from the interior of the battery cell 20, i.e., the first surface 251 is disposed away from the interior of the housing 21 of the battery cell 20, and the first groove 252 and the notch 249 are provided on a side of the pressure relief member 24 that is away from the electrode assembly 22 of the battery cell 20. Of course, in other embodiments, the first groove 252 and the notch 249 may be provided on a side of the pressure relief member 24 that faces the interior of the housing 21 of the battery cell 20.

[0254] By positioning the first surface 251 as a surface of the pressure relief member 24 that is away from the inside of the battery cell 20, the cutout 249 is positioned on one side of the pressure relief member 24 that is away from the inside of the battery cell 20, which is advantageous because it reduces the difficulty of processing the cutout 249 and makes it easier to process and form the cutout 249 in the pressure relief member 24.

[0255] According to some embodiments of the present application, as still shown in Figures 5 and 6, along the thickness direction X of the pressure relief member, the pressure relief member 24 has a second surface 253 opposite to the first surface 251, and a second groove 254 is provided at a position corresponding to the first groove 252 on the second surface 253, and the extension direction of the second groove 254 is the same as the extension direction of the first groove 252.

[0256] Here, the pressure release member 24 has a second surface 253 opposite to the first surface 251 in the thickness direction X of the pressure release member, that is, the pressure release member 24 has a first surface 251 and a second surface 253 on both sides of the pressure release member in the thickness direction X.

[0257] A second groove 254 is provided at a position corresponding to the first groove 252 on the second surface 253, and the extension direction of the second groove 254 is the same as the extension direction of the first groove 252, that is, the first groove 252 and the second groove 254 are arranged opposite each other in the thickness direction X of the pressure relief member, and the shapes of the first groove 252 and the second groove 254 are the same, so that the cut groove 249 is provided in the region where the pressure relief member 24 is located between the groove bottom surface of the first groove 252 and the groove bottom surface of the second groove 254, and the pressure relief member 24 is located in the region between the groove bottom surface of the first groove 252 and the groove bottom surface of the second groove 254 where the cut groove 249 is not provided, and the region located between the cut groove 249 and the reinforcing portion 242 is a second fragile portion 250.

[0258] The pressure relief member 24 further has a second surface 253 opposite to the first surface 251. A second groove 254 is formed on the second surface 253 at a position corresponding to the first groove 252, extending in the same direction as the first groove 252. This allows the area of ​​the pressure relief member 24 where the cut groove 249 is to be formed to be locally thinned by the first groove 252 and the second groove 254. This allows the pressure relief member 24 to be thinned from both sides by the first groove 252 and the second groove 254 before the second weakened portion 250 is formed, which is advantageous for ease of handling and processing and reduces the difficulty of forming the second weakened portion 250 on the pressure relief member 24. On the other hand, this improves the shape of the flowable material during the formation of the cut groove 249. This is advantageous for the material generated during the formation of the cut groove 249 to flow, which is advantageous for improving the structural consistency of the cut groove 249.

[0259] According to some embodiments of the present application, as shown in Figures 10, 11 and 12, the pressure relief portion 241 and the reinforcing portion 242 are installed separately, the pressure relief portion 241 is attached to the reinforcing portion 242, and a notch 249 is formed in the pressure relief portion 241, so that the pressure relief portion 241 can tear along the notch 249 when the battery cell 20 is released from pressure.

[0260] Here, the pressure relief portion 241 and the reinforcing portion 242 are installed separately, that is, the pressure relief portion 241 is a component installed independently on the pressure relief member 24, and the pressure relief portion 241 may be attached to the reinforcing portion 242 by a process such as welding.

[0261] The pressure relief portion 241 is provided with a notch 249, and the pressure relief portion 241 can tear along the notch 249 when the battery cell 20 is released from pressure, that is, the notch 249 is provided in the pressure relief portion 241, forming a weakened area in the pressure relief portion 241, so that the pressure relief portion 241 can tear along the notch 249 when the battery cell 20 is released from pressure, thereby releasing the internal pressure of the battery cell 20.

[0262] For example, the pressure relief part 241 may be an explosion-proof valve, an explosion-proof sheet, an air valve, a pressure relief valve, a safety valve, or the like.

[0263] By installing the pressure relief portion 241 and the reinforcing portion 242 as separate components and providing a notch 249 in the pressure relief portion 241, the internal pressure of the battery cell 20 can be released after the pressure relief portion 241 tears along the notch 249. Adopting such a structure is advantageous because it reduces the difficulty of installing the pressure relief portion 241 in the pressure relief member 24, thereby reducing the difficulty of manufacturing the pressure relief member 24, and further improves the production efficiency of the pressure relief member 24.

[0264] According to some embodiments of the present application, as shown in FIGS. 3 and 4 , the embodiments of the present application further provide a battery cell 20, which includes a pressure relief member 24 of any one of the above solutions, and the pressure relief member 24 is configured to release the internal pressure of the battery cell 20.

[0265] Here, the battery cell 20 includes a housing 21, and the pressure relief member 24 is installed in the housing 21. Alternatively, the pressure relief member 24 may be installed in a variety of structures in the housing 21 of the battery cell 20. The pressure relief member 24 may be installed separately from the housing 21, or may be a wall of the housing 21. In the case where the pressure relief member 24 and the housing 21 are installed separately, that is, the housing 21 has a pressure relief hole for installing the pressure relief member 24, and the pressure relief member 24 is connected to the housing 21 and covers the pressure relief hole. The connection between the pressure relief member 24 and the housing 21 may be in a variety of ways, such as welding or fastening. Similarly, the pressure relief member 24 may be attached to an end cap 212 of the housing 21 or to the case 211 of the housing 21. When the pressure relief member 24 is one wall of the housing 21, that is, when the pressure relief member 24 is integrated into the housing 21 and forms one wall of the housing 21, the pressure relief member 24 may be an end cap 212 of the housing 21 or may be one wall of the case 211 of the housing 21.

[0266] According to some embodiments of the present application, referring to Figures 4, 5 and 6, or referring to Figures 8 and 9, or referring to Figures 10, 11 and 12, the battery cell 20 further includes a housing 21, the housing 21 has a wall portion 213, and the pressure relief member 24 is the wall portion 213.

[0267] Here, the housing 21 has a wall 213, and the pressure relief member 24 is the wall 213, i.e., the pressure relief member 24 is one wall of the housing 21, that is, the pressure relief member 24 is integrated into the housing 21, and the pressure relief member 24 can be an end cap 212 of the housing 21, so that the pressure relief member 24 can seal the opening 2111 of the case 211; of course, the pressure relief member 24 can also be one wall of the case 211, so that the pressure relief member 24 can be surrounded by another wall of the case 211 to form an accommodating cavity for accommodating the electrode assembly 22.

[0268] 4, 5 and 6, the pressure relief member 24 is an end cap 212 of the housing 21 of the battery cell 20, and the pressure relief member 24 is connected to the case 211 and covers the opening 2111 of the case 211.

[0269] 10, 11, and 12, the pressure relief member 24 is one wall of the case 211 of the housing 21, and the pressure relief member 24 is connected to another wall of the case 211 to surround and form an accommodating cavity for accommodating the electrode assembly 22. In such an embodiment, the electrode terminal 23 may be attached to the case 211 or the end cap 212. For example, in FIG. 10, the electrode terminal 23 is attached to the end cap 212.

[0270] It should be noted that in an embodiment in which the pressure relief member 24 is one wall of the end cap 212 or the case 211 of the housing 21, the pressure relief portion 241 of the pressure relief member 24 may have an integral structure with the reinforcing portion 242 or a separate structure. For example, in Figures 4, 5 and 6, the pressure relief portion 241 and the reinforcing portion 242 are an integrally molded structure, and in Figures 10, 11 and 12, the pressure relief portion 241 and the reinforcing portion 242 are separate structures.

[0271] The housing 21 has a wall portion 213, and the pressure relief member 24 is the wall portion 213 of the housing 21, i.e., the pressure relief member 24 is one wall of the housing 21, so that the first weak portion 243 of the pressure relief member 24 can effectively absorb the deformation energy generated by the housing 21 when the housing 21 of the battery cell 20 is deformed, and protect the pressure relief portion 241.

[0272] In some embodiments, the battery cell 20 may have other structures, for example, the battery cell 20 further includes a housing 21, the housing 21 having a wall 213, the wall 213 having a pressure relief hole, and the pressure relief member 24 attached to the wall 213 and covering the pressure relief hole.

[0273] Here, the pressure relief member 24 is attached to the wall 213 and covers the pressure relief hole, i.e., the pressure relief member 24 is a member independent of the housing 21, i.e., the pressure relief member 24 and the housing 21 are installed as separate bodies, and the pressure relief member 24 is connected to the wall 213 of the housing 21 by a process such as welding and covers the pressure relief hole installed in the wall 213 of the housing 21, so that when the pressure relief portion 241 of the pressure relief member 24 is destroyed, the battery cell 20 can release the internal pressure of the battery cell 20 through the pressure relief hole.

[0274] The housing 21 has a wall 213, and the pressure relief member 24 is attached to the wall 213 and covers the pressure relief hole of the wall 213; that is, the pressure relief member 24 and the housing 21 are installed as separate bodies, and the pressure relief member 24 is an independent member attached to one wall of the housing 21. Adopting such a structure is advantageous because it reduces the difficulty of assembly between the pressure relief member 24 and the housing 21, thereby improving the production efficiency of the battery cells 20.

[0275] According to some embodiments of the present application, as shown in Figures 3, 4, and 5, the housing 21 may include a case 211 and an end cap 212. An accommodating cavity having an opening 2111 for accommodating the electrode assembly 22 is formed inside the case 211. The end cap 212 seals the opening 2111, and the end cap 212 has a wall portion 213.

[0276] Here, the end cap 212 is the wall 213, i.e., the pressure relief member 24 is the end cap 212 or the pressure relief member 24 is attached to the end cap 212; that is, in an embodiment where the pressure relief member 24 is the wall 213 of the housing 21, the pressure relief member 24 is the end cap 212 of the housing 21; in an embodiment where the pressure relief member 24 is attached to the wall 213 of the housing 21, a pressure relief hole is provided in the end cap 212, and the pressure relief member 24 is attached to the end cap 212 and covers the pressure relief hole.

[0277] By setting the wall portion 213 of the housing 21 as the end cap 212 for the housing 21 to seal the opening 2111 of the case 211, the battery cell 20 adopting such a structure is advantageous because the pressure relief member 24 is attached to the end cap 212 or the pressure relief portion 241 and the first weak portion 243 are formed, thereby effectively reducing the processing difficulty of the battery cell 20 and improving the production efficiency of the battery cell 20.

[0278] 10 , 11 , and 12 , the housing 21 may include a case 211 and an end cap 212. The case 211 has an interior formed with a receiving cavity having an opening 2111 for receiving the electrode assembly 22. The end cap 212 seals the opening 2111, and the case 211 includes a wall portion 213.

[0279] Here, the case 211 includes a wall 213, i.e., the pressure relief member 24 is one wall of the case 211 or the pressure relief member 24 is attached to one wall of the case 211; that is, in an embodiment in which the pressure relief member 24 is the wall 213 of the housing 21, the pressure relief member 24 is one wall of the case 211, and in an embodiment in which the pressure relief member 24 is attached to the wall 213 of the housing 21, a pressure relief hole is provided in one wall of the case 211, and the pressure relief member 24 is attached to one wall of the case 211 and covers the pressure relief hole.

[0280] 10 , the case 211 includes integrally molded side walls and a bottom wall. The side walls are disposed around the periphery of the bottom wall. One end of the side wall is connected to the bottom wall and the other end surrounds the bottom wall to form an opening 2111 along the thickness direction of the bottom wall. The bottom wall is disposed opposite an end cap 212. The side walls and the bottom wall together define an accommodating cavity for accommodating the electrode assembly 22, and the end cap 212 seals the opening 2111. Here, the side walls include four walls connected in order, and the four walls include two first walls 2112 disposed opposite to each other and two second walls 2113 disposed opposite to each other. The first walls 2112 are the surfaces with the largest area among the outer surfaces of the battery cell 20. Optionally, the wall portions 213 may be the bottom wall of the case 211, the first walls 2112 of the case 211, or the second walls 2113 of the case 211. For example, in FIG. 10 , the wall portion 213 is the second wall 2113 of the case 211, and the pressure relief member 24 is the second wall 2113 of the case 211. The first wall 2112 is the surface with the largest area among the outer surfaces of the battery cell 20, so the first wall 2112 is more likely to deform during use of the battery cell 20, and the amount of deformation is relatively large. Therefore, by installing the pressure relief member 24 as the second wall 2113 of the case 211, the deformation of the pressure relief member 24 can be effectively alleviated, and the first weak portion 243 can effectively absorb the deformation energy generated by the first wall 2112, thereby improving the protective effect of the pressure relief member 24 on the pressure relief portion 241.

[0281] By installing the wall portion 213 of the housing 21 as one wall of the case 211, the battery cell 20 adopting this structure can reduce the impact on the pressure relief portion 241 of the stress generated when the end cap 212 and the case 211 are connected to each other, thereby reducing phenomena such as cracks occurring in the pressure relief portion 241 and the first weak portion 243, and further improving the usage stability and service life of the battery cell 20.

[0282] According to some embodiments of the present application, the embodiments of the present application further provide a battery 100 including the battery cell 20 of any one of the above solutions.

[0283] Here, as shown in FIG. 2, the battery 100 may further include a housing 10, and the battery cells 20 are housed within the housing 10.

[0284] In some embodiments, the housing 10 may include a first housing body 11 and a second housing body 12, the first housing body 11 and the second housing body 12 being fitted over each other, and the first housing body 11 and the second housing body 12 jointly defining an assembly space for accommodating the battery cells 20.

[0285] Alternatively, the second housing body 12 may have a hollow structure with one end open, and the first housing body 11 may have a plate-like structure, with the first housing body 11 placed over the open side of the second housing body 12, so that the first housing body 11 and the second housing body 12 jointly define the assembly space; the first housing body 11 and the second housing body 12 may both have a hollow structure with one end open, with the open side of the first housing body 11 placed over the open side of the second housing body 12.

[0286] Of course, the housing 10 formed by the first housing body 11 and the second housing body 12 may have various shapes, such as a cylinder or a rectangular parallelepiped, etc. Illustratively, in FIG. 2, the housing 10 has a rectangular parallelepiped structure.

[0287] Alternatively, the number of battery cells 20 installed within the housing 10 may be one or more. For example, in FIG. 2 , a plurality of battery cells 20 are installed within the housing 10 of the battery 100, and the plurality of battery cells 20 may be connected in series, parallel, or series-parallel, where series-parallel connection refers to both series and parallel connections among the plurality of battery cells 20. The plurality of battery cells 20 may be directly connected in series, parallel, or series-parallel, and the entire plurality of battery cells 20 may be housed within the housing 10. Of course, the battery 100 may be formed by first connecting the plurality of battery cells 20 in series, parallel, or series-parallel to form a battery module, and then connecting the plurality of battery modules in series, parallel, or series-parallel to form an integrated battery module housed within the housing 10.

[0288] Here, each battery 100 may further include other structures, for example, the battery 100 may further include bus bar members, which are connected to the multiple battery cells 20 to realize electrical connection between the multiple battery cells 20.

[0289] It should be noted that in some embodiments, the battery 100 may not be provided with the housing 10, and the battery 100 may include a plurality of battery cells 20. The battery 100, which is made up of the plurality of battery cells 20, may be directly assembled to a power consuming device, thereby providing electrical energy to the power consuming device via the plurality of battery cells 20. That is, the housing 10 may be a part of the power consuming device. For example, the power consuming device may be a vehicle 1000, and the housing 10 may be a part of the chassis structure of the vehicle 1000. For example, a portion of the housing 10 may form at least a portion of the floor of the vehicle 1000, or a portion of the housing 10 may form at least a portion of a cross member and a side member of the vehicle 1000.

[0290] According to some embodiments of the present application, the embodiments of the present application further provide a power consuming device, which includes a battery 100 of any one of the above solutions, and the battery 100 is used to provide electrical energy to the power consuming device.

[0291] Here, the power consuming device may be any one of the above-mentioned devices or systems that utilizes the battery 100.

[0292] According to some embodiments of the present application, as shown in Figures 4 to 7, the present application provides a pressure relief member 24, which includes an integrally molded main body 245, a pressure relief portion 241, a reinforcing portion 242, and a first weak portion 243. The pressure relief portion 241 has an annular structure and is configured to tear when the battery cell 20 is released to release the internal pressure of the battery cell 20. The reinforcing portion 242 is connected to the pressure relief portion 241 and surrounds the pressure relief portion 241. The pressure relief member 24 is provided with a first groove 244, which is provided on one side of the pressure relief member 24 facing the inside of the battery cell 20. The pressure relief member 24 forms a first weak portion 243 in the area where the first groove 244 is provided. The first groove 244 is an annular groove, giving the first weak portion 243 an annular structure. The first fragile portion 243 connects the reinforcing portion 242 and the main body portion 245, and the first fragile portion 243 surrounds the outside of the reinforcing portion 242. The thickness of the first fragile portion 243 is smaller than the thickness of the reinforcing portion 242 and the thickness of the main body portion 245. A second groove 247 is formed on one side of the pressure release member 24 that is away from the inside of the battery cell 20 along the thickness direction X of the pressure release member, and a protrusion 248 is formed on the other side at a position corresponding to the second groove 247. The reinforcing portion 242 surrounds the groove side wall of the second groove 247, and the first fragile portion 243 is connected to the outside of the reinforcing portion 242 along the radial direction of the reinforcing portion 242. The first groove 244 is provided on the groove bottom surface of the second groove 247, so that the groove bottom wall of the second groove 247 includes the pressure release portion 241. The pressure release member 24 has a first surface 251 and a second surface 253 facing each other along the thickness direction X of the pressure release member. The first surface 251 is positioned away from the interior of the battery cell 20. A first groove 252 is formed in the first surface 251. A cut groove 249 is formed in the bottom surface of the first groove 252. The extension direction of the first groove 252 is the same as the extension direction of the cut groove 249. The first groove 252 and the cut groove 249 are both annular grooves. The bottom wall of the first groove 252 includes a second fragile portion 250. A second groove 254 is formed in the second surface 253 at a position corresponding to the first groove 252. The extension direction of the second groove 254 is the same as the extension direction of the first groove 252. Here, the thickness of the first fragile portion 243 is D1, and the thickness of the main body portion 245 is D2, satisfying 0.5D2≦D1≦0.7D2.The groove width of the first groove 244 is W, which satisfies 2 mm≦W≦5 mm.

[0293] 3 and 4 , according to some embodiments of the present application, the present application provides a battery cell 20, which includes a housing 21, an electrode assembly 22, and a pressure relief member 24. The housing 21 includes a case 211 and an end cap 212. An accommodating cavity having an opening 2111 is formed inside the case 211. The electrode assembly 22 is accommodated in the accommodating cavity, and the end cap 212 seals the opening 2111. The pressure relief member 24 is the end cap 212.

[0294] It should be noted that, unless there is a conflict, the embodiments and features in the embodiments in the present application can be combined with each other.

[0295] The above is only a preferred embodiment of the present application, and is not intended to limit the present application. Those skilled in the art can make various modifications and variations to the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application. [Explanation of symbols]

[0296] 1000 - vehicle, 100 - battery, 10 - housing, 11 - first box body, 12 - second box body, 20 - battery cell, 21 - housing, 211 - case, 2111 - opening, 2112 - first wall, 2113 - second wall, 212 - end cap, 213 - wall portion, 22 - electrode assembly, 221 - tab, 23 - electrode terminal, 24 - pressure relief member, 241 - pressure relief portion, 242 - reinforcing portion, 2421 - strip-shaped segment, 2 422—arc segment, 243—first weakened portion, 244—first recessed portion, 245—main body portion, 246—protrusion, 247—second recessed portion, 248—protrusion portion, 249—notched groove, 250—second weakened portion, 251—first surface, 252—first groove, 253—second surface, 254—second groove, 255—protrusion portion, 200—controller, 300—motor, X—thickness direction of pressure relief member, Y—first direction, Z—second direction

Claims

1. A pressure relief member for use in a battery cell, a pressure relief portion configured to break when the battery cell is released from pressure to release the internal pressure of the battery cell; a reinforcing portion connected to the pressure relief portion and surrounding the pressure relief portion; a first weak portion connected to the pressure relief portion via the reinforcing portion, the first weak portion having a rigidity lower than a rigidity of the reinforcing portion; A pressure relief member comprising:

2. The pressure release member according to claim 1 , wherein the thickness of the first weak portion is smaller than the thickness of the reinforcing portion.

3. The pressure relief member further includes a main body portion, the first fragile portion connects the main body portion and the reinforcing portion, The pressure release member according to claim 1 or 2, wherein the first weak portion has a rigidity lower than that of the main body portion.

4. The pressure release member according to claim 3 , wherein the thickness of the first weakened portion is smaller than the thickness of the main body portion.

5. The thickness of the first weak part is D １ and the thickness of the main body is D ２ and 0.3D ２ ≦D １ ≦0.9D ２ The pressure release member according to claim 4 , which satisfies the above.

6. 0.5D ２ ≦D １ ≦0.7D ２ The pressure relief member according to claim 5 , which satisfies the above.

7. The pressure release member according to claim 3 , wherein a first recessed groove is provided in the pressure release member, and the pressure release member forms the first weakened portion in a region where the first recessed groove is provided.

8. The pressure release member according to claim 7 , wherein the first groove has a width W, which satisfies 0.5 mm≦W≦10 mm.

9. The pressure release member according to claim 8, wherein 2 mm≦W≦5 mm is satisfied.

10. The pressure relief member according to claim 7 , wherein the first groove is disposed on one side of the pressure relief member facing the inside of the battery cell.

11. The pressure relief member according to claim 7 , wherein the first groove is disposed on one side of the pressure relief member that is away from the interior of the battery cell.

12. The pressure release member according to claim 7 , wherein the first groove is provided on both sides of the pressure release member.

13. The pressure release member according to claim 7 , wherein a protrusion is formed on one side of the pressure release member away from the first groove at a position corresponding to the first groove.

14. The pressure release member according to claim 13 , wherein a projection of the protrusion covers a portion of a bottom surface of the first recessed groove along a thickness direction of the first weakened portion.

15. The pressure relief member of claim 14, wherein the groove width of the first groove is W, and the size of the portion of the first fragile portion where the protrusion is not formed along the groove width direction of the first groove is L, and 0.1W≦L≦0.5W is satisfied.

16. The pressure release member according to claim 1 , wherein the first weakened portion has an annular structure extending along a circumferential direction of the reinforcing portion.

17. a size of the pressure release member in a first direction is smaller than a size of the pressure release member in a second direction, and two of the first direction, two of the second direction, and two of the thickness direction of the pressure release member are perpendicular to each other; The pressure release member according to claim 1 , wherein the first weak portion is disposed on at least one side of the reinforcing portion along the first direction.

18. The pressure release member according to claim 17 , wherein the first weak portions are respectively disposed on both sides of the reinforcing portion along the first direction.

19. The pressure release member according to claim 17 or 18, wherein the length of the first weak portion in the second direction is greater than the size of the pressure release portion in the second direction.

20. The pressure release member according to claim 19 , wherein both ends of the first weak portion extend to both ends of the pressure release member along the second direction.

21. a second recessed groove is formed on one side of the pressure release member that is away from the inside of the battery cell along the thickness direction of the pressure release member, and a protrusion is formed on the other side at a position corresponding to the second recessed groove; The pressure release member according to claim 1 , wherein a bottom wall of the second groove includes the pressure release portion.

22. The pressure relief member according to claim 21, wherein the reinforcing portion is formed surrounding a groove side wall of the second groove, and the first weak portion is connected to the outside of the reinforcing portion along a radial direction of the reinforcing portion.

23. The pressure relief member further includes a main body portion, the first weak portion connects the main body portion and the reinforcing portion, and the rigidity of the first weak portion is smaller than the rigidity of the main body portion; The pressure relief member of claim 21, wherein the groove side wall of the second groove includes the first weak portion, and the first weak portion is connected between the main body portion and the reinforcing portion along the thickness direction of the pressure relief member.

24. 24. A pressure relief member according to claim 1, wherein the pressure relief portion is integrally molded with the reinforcing portion, a cut groove is provided in the pressure relief member, the pressure relief member forms the pressure relief portion in the area where the cut groove is provided, and the pressure relief member tears along the cut groove when the battery cell releases pressure.

25. The pressure relief member further includes a second weak portion, The pressure relief member of claim 24, wherein the reinforcement portion is connected to the pressure relief portion via the second weak portion, and the thickness of the second weak portion is smaller than the thickness of the reinforcement portion and larger than the thickness of the pressure relief portion.

26. The pressure release member has a first surface along a thickness direction of the pressure release member, and a first groove is provided on the first surface, The pressure relief member of claim 25, wherein the cut groove is provided on the bottom surface of the first groove, the extension direction of the first groove is the same as the extension direction of the cut groove, and the bottom wall of the first groove includes the second weak portion.

27. 27. The pressure relief member according to claim 26, wherein the first groove and the cut groove are both annular grooves.

28. The pressure relief member according to claim 26 or 27, wherein the first surface is disposed away from the interior of the battery cell along a thickness direction of the pressure relief member.

29. A pressure relief member as described in any one of claims 26 to 28, wherein the pressure relief member has a second surface opposite to the first surface along the thickness direction of the pressure relief member, a second groove is provided at a position corresponding to the first groove on the second surface, and the extension direction of the second groove is the same as the extension direction of the first groove.

30. 24. A pressure relief member according to claim 1, wherein the pressure relief portion and the reinforcing portion are installed separately, the pressure relief portion is attached to the reinforcing portion, a cut groove is provided in the pressure relief portion, and the pressure relief portion tears along the cut groove when the battery cell releases pressure.

31. A battery cell, comprising the pressure relief member of any one of claims 1 to 30, wherein the pressure relief member is configured to relieve internal pressure of the battery cell.

32. The battery cell is further comprising a housing having a wall; The battery cell according to claim 31 , wherein the pressure relief member is the wall portion.

33. The battery cell is a housing having a wall with a pressure relief hole; The battery cell according to claim 31 , wherein the pressure relief member is attached to the wall portion and covers the pressure relief hole.

34. The housing includes: a case having an accommodating cavity formed therein with an opening, the accommodating cavity being used to accommodate an electrode assembly; an end cap sealing the opening; Including, 34. The battery cell of claim 32 or 33, wherein the end cap is the wall portion.

35. The housing includes: a case having an accommodating cavity formed therein with an opening, the accommodating cavity being used to accommodate an electrode assembly; an end cap sealing the opening; Including, 34. The battery cell according to claim 32 or 33, wherein the case includes the wall portion.

36. A battery comprising the battery cell of any one of claims 31 to 35.

37. 37. A power consuming device comprising the battery of claim 36.

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