Patent Publication Number: US-2023163410-A1

Title: Exhaust apparatus, battery cell, battery, and electric apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of International Application PCT/CN2021/121368, filed Sep. 28, 2021 and entitled “EXHAUST APPARATUS, BATTERY CELL, BATTERY, AND ELECTRIC APPARATUS”, which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     This application relates to the field of battery technologies, and in particular, to an exhaust apparatus, a battery cell, a battery, an electric apparatus, and a manufacturing method and manufacturing device of exhaust apparatus. 
     BACKGROUND 
     Batteries are widely used in electronic devices such as mobile phones, laptops, battery carts, electric vehicles, electric aircrafts, electric ships, electric toy cars, electric toy ships, electric toy aircrafts, and electric tools. 
     In the development of battery technologies, in addition to performance improvement of battery cells, safety is also an issue that needs to be considered. Therefore, how safety performance of battery cells is enhanced is an urgent issue that needs to be solved in battery technologies. 
     SUMMARY 
     Embodiments of this application provide an exhaust apparatus, a battery cell, a battery, an electric apparatus, a method, and a device. Such exhaust apparatus can meet internal gas exhaust requirements of battery cells, and can also ensure safety performance of battery cells. 
     According to a first aspect, an embodiment of this application provides an exhaust apparatus applied to a battery cell, including an exhaust body and an exhaust mechanism including a connection member and a ventilation member that are provided on the exhaust body, where the connection member is configured to connect the exhaust body, the connection member is provided with a plurality of first through holes, the ventilation member covers the plurality of first through holes, and the ventilation member is configured to, when a pressure of gas inside the battery cell reaches a first threshold, exhaust the gas to the outside of the battery cell through the plurality of first through holes; and the connection member includes a connection portion formed between two adjacent ones of the first through holes, and the connection portion is configured to attach to the ventilation member to limit deformation of the ventilation member. 
     In the foregoing technical solution, the exhaust apparatus includes an exhaust body and an exhaust mechanism, where the exhaust mechanism includes a connection member and a ventilation member that are provided on the exhaust body, the connection member is provided with a plurality of first through holes, the ventilation member covers the plurality of first through holes, and when a pressure of gas inside a battery cell reaches a first threshold, the gas is exhausted to the outside of the battery cell through the ventilation member and the plurality of first through holes, so as to achieve the purpose of exhausting the gas inside the battery cell. The connection member includes the connection portion formed between two adjacent ones of the first through holes, and therefore it can be attached to the ventilation member through the connection portion. When the gas inside the battery cell acts on the ventilation member in the process of exhaust to the outside of the battery cell through the ventilation member, the connection portion may provide the ventilation member with a counterforce against the gas pressure in the battery cell to reduce deformation of the ventilation member, improve the overall internal pressure resistance of the exhaust apparatus, and further enhance safety performance of the battery cell. 
     In some embodiments, the ventilation member is provided on a side of the connection member close to the inside of the battery cell, and the connection portion is configured to provide an anchorage force for the ventilation member when the ventilation member deforms towards the outside of the battery cell. 
     In the foregoing technical solution, the ventilation member is provided on the side of the connection member close to the inside of the battery cell. In the exhaust process, the connection member can provide an anchorage force for the ventilation member, ensuring sufficient exhaust area, avoiding deformation or displacement of the ventilation member due to excessive pressure in the battery cell, ensuring the integrity of the ventilation member, and enhance safety performance of the ventilation member. In addition, the ventilation member is provided on the side of the connection member close to the inside of the battery cell. Such position arrangement can increase the utilization of an exterior space of the end cover and facilitate the placement of other components. 
     In some embodiments, the plurality of first through holes have same shape and equal area. 
     In the foregoing technical solution, the plurality of first through holes having the same shape and equal area is beneficial for the gas to uniformly and quickly pass through the plurality of first through holes in the exhaust process. This enables the ventilation member to bear the same gas pressure as the corresponding component, avoiding deformation of the ventilation member under the action of gas due to the uneven distribution of the plurality of first through holes. Moreover, the plurality of first through holes may be processed by punching or milling. By making the plurality of first through holes have same shape and equal area, the same processing procedure may be used to process the first through holes, which can simplify the processing procedure, reduce the machining costs, and improve the forming efficiency. 
     In some embodiments, the plurality of first through holes are spaced apart from each other, and a minimum distance D between two adjacent ones of the first through holes and a thickness L of the ventilation member in an axial direction of the first through hole satisfy 1.2≤D/L≤5. 
     In the foregoing technical solution, the minimum distance D between the two adjacent ones of the first through holes and the thickness L of the ventilation member in the axial direction of the first through hole satisfy 1.2≤D/L≤5, which not only can ensure the mechanical strength of the connection portion and the attachment area between the connection portion and the ventilation member, but also can decrease a probability of deformation of the ventilation member under the action of the internal pressure of the battery cell. 
     In some embodiments, the first through hole is in one of a circular shape, an ellipse shape, a kidney shape, and a polygon shape. 
     In the foregoing technical solution, the first through hole being in one of a circular shape, an ellipse shape, a kidney shape, and a polygon shape not only can ensure the exhaust efficiency in the exhaust process, but also can make the first through holes have a regular geometric shape or an approximately regular geometric shape, which is beneficial to the processing and forming of the first through holes. 
     In some embodiments, the first through hole is circular, and a bore diameter d of the first through hole and a minimum distance D between two adjacent ones of the first through holes satisfy 0.1≤d/D≤4. 
     If the bore diameter d of the first through hole is too small, the minimum distance D between two adjacent ones of the first through holes is too large, in other words, when d/D&lt;0.1, under the condition that the ventilation area remains unchanged, an area occupied by the overall distribution of the first through holes is too large, which is not conducive to the assembly of other components; and if the bore diameter d of the first through hole is too large, the minimum distance D between the two adjacent ones of the first through holes is too small, in other words, when d/D&gt;4, a jointing area between the connection portion and the ventilation member is too small, and correspondingly, connection strength therebetween is too small, which may lead to separation of the ventilation member from the connection portion, thereby affecting the performance of the ventilation member and making the ventilation member be prone to a risk of deformation when the internal pressure of the battery cell is too high. In the foregoing technical solution, the first through hole is circular, and the bore diameter d of the first through hole and the minimum distance D between the two adjacent ones of the first through holes satisfy 0.1≤d/D≤4, which can make a ratio of the bore diameter d of the first through hole and the minimum distance D between the two adjacent ones of the first through holes be moderate, so as to avoid excessively large area being occupied by the plurality of first through holes caused by the excessively large or small ratio of the two, or avoid separation of the ventilation member from the connection portion caused by insufficient attachment strength therebetween. 
     In some embodiments, the minimum distance D between two adjacent ones of the first through holes satisfies D≥0.5 mm. 
     In the foregoing technical solution, the minimum distance D between two adjacent ones of the first through holes satisfies D≥0.5 mm, which can ensure the effective contact area of a matching portion between the connection portion and the ventilation member, and ensure the requirements for attachment strength between the connection portion and the ventilation member. 
     In some embodiments, in the axial direction of the first through hole, a sum S1 of orthographic projection areas of all of the first through holes and an orthographic projection area S2 of the ventilation member satisfy S1/S2≤0.8. 
     In the foregoing technical solution, in the axial direction of the first through hole, the sum S1 of the orthographic projection areas of all of the first through holes and the orthographic projection area S2 of the ventilation member satisfy S1/S2≤0.8, which can ensure the effective contact area of the matching portion between the connection portion and the ventilation member, enhance the attachment strength between the ventilation member and the ventilation member, decrease a probability of deformation of the ventilation member, and ensure integrity and reliability of the ventilation member. 
     In some embodiments, the exhaust body and the exhaust mechanism are provided separately, and the exhaust mechanism is connected to the exhaust body through the connection member. 
     In the foregoing technical solution, the exhaust body and the exhaust mechanism are separately formed, and the exhaust mechanism is connected to the exhaust body through the connection member, so that the exhaust body and the exhaust mechanism are independent components, which is convenient for processing and assembly. In addition, this separate-forming method enables the exhaust body and the exhaust mechanism to be processed and manufactured separately from different materials, such that an appropriate material and processing technology can be selected for the entire exhaust apparatus according to the structural characteristics and usage requirements of the exhaust mechanism. 
     In some embodiments, the exhaust body is provided with a first concave portion, and the first concave portion is configured to accommodate at least part of the exhaust mechanism. 
     In the foregoing technical solution, the first concave portion is configured to accommodate at least part of the exhaust mechanism, which can reduce the occupied space of the entire exhaust apparatus, and such arrangement of the first concave portion can enable positioning of the exhaust mechanism for installation and reduce assembly difficulty between the exhaust mechanism and the exhaust body. 
     In some embodiments, the connection member includes a body region and an exhaust region, where the body region is configured to connect the exhaust body, the exhaust region includes the connection portion and the plurality of first through holes, one part of the ventilation member is attached to the body region, and the other part of the ventilation member is attached to the connection portion of the exhaust region; and the exhaust body is provided at the bottom of the first concave portion with a shielding portion and a second through hole, the shielding portion is configured to shield at least part of the exhaust region, and the second through hole is configured to communicate with a space defined by the first concave portion. 
     In the foregoing technical solution, the connection member includes the body region and the exhaust region, and can be connected to the exhaust body through the body region to ensure the connection strength between the connection member and the exhaust body. The gas inside the battery cell can be exhausted through the exhaust region to ensure safety performance of the battery cell. Because one part of the ventilation member is attached to the body region and the other part of the ventilation member is attached to the exhaust region, to be specific, the ventilation member is attached not only to the connection portion but also to the body region, the attachment strength between the ventilation member and the connection member can be ensured, the risk of separation of the ventilation member from the connection member can be reduced. The shielding portion is configured to shield at least part of the exhaust region, and the shielding portion can prevent at least part of impurities from entering the plurality of first through holes, thereby avoiding influence on the ventilation member and ensuring performance of the ventilation member. The second through hole is configured to communicate with the space defined by the first concave portion, so that the gas inside the battery cell can be exhausted normally, so as to ensure safety performance of the battery cell. 
     In some embodiments, the shielding portion completely shields the exhaust region in the axial direction of the first through hole, and the second through hole is completely staggered from the exhaust region. 
     In the foregoing technical solution, in the axial direction of the first through hole, the shielding portion completely shields the exhaust region, and the second through hole is completely staggered from the exhaust region, which can not only ensure the internal gas exhaust requirements of the battery cell but also effectively protect the connection member and ventilation member through the shielding portion, decreasing a probability that the ventilation member is damaged or corroded by external impurities or internal electrolyte. 
     In some embodiments, the shielding portion is provided with a second concave portion, where the second concave portion is recessed from the bottom of the first concave portion in a direction leaving away from the ventilation member, and an avoidance space is formed between the bottom of the second concave portion and the exhaust mechanism to avoid the exhaust region. 
     In the foregoing technical solution, the shielding portion is provided with the second concave portion, and the avoidance space is formed between the bottom of the second concave portion and the exhaust mechanism, so that in the axial direction of the first through hole, when the orthographic projections of at least part of the first through holes are covered by the shielding portion, the shielding portion can be prevented from contacting the exhaust region of the connection member, thereby preventing the shielding portion from closing the first through holes covered by the shielding portion, ensuring the internal gas exhaust requirements of the battery cell and enhancing safety performance of the battery cell. 
     In some embodiments, the exhaust apparatus further includes a ventilation limiting member, where the ventilation limiting member is at least partially located in the second concave portion and is configured to limit deformation of the exhaust region. 
     In the foregoing technical solution, the exhaust apparatus further includes the ventilation limiting member, and the ventilation limiting member is at least partially located in the second concave portion to limit deformation of the exhaust region, thereby decreasing a probability of deformation of the ventilation member and enhancing safety performance of the exhaust apparatus. 
     In some embodiments, the ventilation limiting member is attached to the exhaust region and supported on the exhaust region. 
     In the foregoing technical solution, the ventilation limiting member is attached to the exhaust region and supported on the exhaust region, which can enhance air pressure resistance of the exhaust region, decrease a probability of deformation of the exhaust region, and further decrease a probability of deformation of a region to which the ventilation member is attached. 
     In some embodiments, the first concave portion is recessed from an outer surface of the exhaust body in a direction approaching towards the inside of the battery cell, the shielding portion is located on a side of the exhaust mechanism close to the inside of the battery cell, and the second through hole is configured to communicate an interior space of the battery cell with the first concave portion. 
     In the foregoing technical solution, the first concave portion is recessed from the outer surface of the exhaust body in the direction approaching towards the inside of the battery cell, the shielding portion is located on the side of the exhaust mechanism close to the inside of the battery cell, and the second through hole is configured to communicate the interior space of the battery cell with the first concave portion, which is convenient for installation and positioning of the exhaust mechanism. 
     In some embodiments, the first concave portion is recessed from an inner surface of the exhaust body in a direction leaving away from the inside of the battery cell, the shielding portion is located on a side of the exhaust mechanism far away from the inside of the battery cell, and the second through hole is configured to communicate an exterior space of the battery cell with the first concave portion. 
     In the foregoing technical solution, the first concave portion is recessed from the inner surface of the exhaust body in the direction leaving away from the inside of the battery cell, the shielding portion is located on the side of the exhaust mechanism far away from the inside of the battery cell, and the second through hole is configured to communicate the exterior space of the battery cell with the first concave portion, so that the gas inside the battery cell can flow through the second through hole and the first through holes in sequence and be exhausted through the ventilation mechanism. A position of the shielding portion can effectively prevent external impurities from entering the first through holes, thereby reducing the risk of damage to the ventilation member. 
     In some embodiments, the ventilation member and the connection member are integrally connected by chemical bonding. 
     In the foregoing technical solution, the ventilation member and the connection member are integrally connected by chemical bonding, such connection between the two components by chemical bonding makes the connection between the ventilation member and the connection member more firmly, ensures the connection strength of the two, gives less influence on performance of the ventilation member, and can guarantee performance of the ventilation member. 
     In some embodiments, an accommodating chamber is formed inside the exhaust body, the exhaust body has a plurality of walls defining the accommodating chamber, and the exhaust mechanism is provided on at least one of the walls. 
     In the foregoing technical solution, the accommodating chamber is formed inside the exhaust body, the exhaust body has the plurality of walls defining the accommodating chamber, and the exhaust mechanism is provided on at least one of the walls, in other words, the exhaust apparatus may be a shell structure capable of accommodating an electrode assembly, and the exhaust apparatus integrates an accommodating function and an exhaust function. 
     In some embodiments, the exhaust body is an end cover of the battery cell. 
     In the foregoing technical solution, the exhaust body is the end cover of the battery cell, in other words, the exhaust mechanism may be the end cover disposed on the battery cell. 
     In some embodiments, the exhaust apparatus further includes an insulating member, where the insulating member is located on a side of the exhaust body close to the inside of the battery cell, the insulating member is provided with a third through hole, and the third through hole is configured to communicate the interior space of the battery cell with the first through holes. 
     In the foregoing technical solution, provision of the insulating member can avoid short circuit caused by contact between the electrode assembly and the end cover metal, and the third through hole provided on the insulating member can communicate the interior space of the battery cell with the first through holes, ensuring the internal gas exhaust requirements of the battery cell. 
     In some embodiments, in the axial direction of the first through hole, the third through hole is completely staggered from the first through hole. 
     In the foregoing technical solution, the insulating member can block liquid or impurity particles, ensuring the performance of the ventilation member, and the foregoing arrangement can also prevent the gas inside the battery cell from directly acting on the first through holes via the third through hole, reducing impact force on the first through holes, decreasing a probability of deformation of the ventilation member, and further ensuring safety performance of the battery cell. 
     According to a second aspect, an embodiment of this application provides a battery cell, including the exhaust apparatus according to any one of the embodiments of the first aspect. 
     According to a third aspect, an embodiment of this application provides a battery, including: the battery cell according to any one of the embodiments of the second aspect; and a box, configured to accommodate the battery cell. 
     According to a fourth aspect, an embodiment of this application provides an electric apparatus, including the battery according to any one of the embodiments of the third aspect, where the battery is configured to supply electric energy. 
     According to a fifth aspect, an embodiment of this application provides a manufacturing method of exhaust apparatus, where the method includes: providing an exhaust body; and providing an exhaust mechanism, and connecting the exhaust mechanism to the exhaust body, where the exhaust mechanism includes a connection member and a ventilation member, the connection member is configured to connect the exhaust body, the connection member is provided with a plurality of first through holes, the ventilation member covers the plurality of first through holes, and the ventilation member is configured to, when a pressure of gas inside the battery cell reaches a first threshold, exhaust the gas to the outside of the battery cell through the plurality of first through holes; and the connection member includes a connection portion formed between two adjacent ones of the first through holes, and the connection portion is configured to attach to the ventilation member to limit deformation of the ventilation member. 
     According to a sixth aspect, an embodiment of this application provides a manufacturing device of exhaust apparatus, where the device includes: a providing apparatus, configured to provide an exhaust body; and an assembly apparatus, configured to provide an exhaust mechanism and connect the exhaust mechanism to the exhaust body, where the exhaust mechanism includes a connection member and a ventilation member, the connection member is configured to connect the exhaust body, the connection member is provided with a plurality of first through holes, the ventilation member covers the plurality of first through holes, and the ventilation member is configured to, when a pressure of gas inside the battery cell reaches a first threshold, exhaust the gas to the outside of the battery cell through the plurality of first through holes; and the connection member includes a connection portion formed between two adjacent ones of the first through holes, and the connection portion is configured to attach to the ventilation member to limit deformation of the ventilation member. 
     The foregoing descriptions are merely an overview of the technical solutions of this application. To understand the technical means of this application more clearly, the technical solutions can be implemented according to the contents of this specification, and to make the preceding and other purposes, features, and advantages of this application more clear and easy to understand, the following specific embodiments of this application are presented. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       To describe the technical solutions in the embodiments of this application more clearly, the following briefly describes the accompanying drawings required for describing the embodiments of this application. Apparently, the accompanying drawings in the following descriptions show merely some embodiments of this application, and a person of ordinary skill in the art may still derive other drawings from the accompanying drawings without creative efforts. 
         FIG.  1    is a schematic structural diagram of a vehicle according to an embodiment of this application; 
         FIG.  2    is a schematic structural diagram of a battery according to some embodiments of this application; 
         FIG.  3    is an exploded view of a battery cell according to some embodiments of this application; 
         FIG.  4    is a top view of an exhaust apparatus according to some embodiments of this application; 
         FIG.  5    is a cross-sectional view along direction A-A in  FIG.  4   ; 
         FIG.  6    is an exploded view of an exhaust apparatus according to some embodiments of this application; 
         FIG.  7    is a top view of a connection member of an exhaust apparatus according to some embodiments of this application; 
         FIG.  8    is a cross-sectional view of an exhaust apparatus according to some other embodiments of this application; 
         FIG.  9    is a top view of an exhaust apparatus according to some other embodiments of this application; 
         FIG.  10    is a cross-sectional view along direction B-B in  FIG.  9   ; 
         FIG.  11    is an exploded view of an exhaust apparatus according to some other embodiments of this application; 
         FIG.  12    is a cross-sectional view of an exhaust apparatus according to still some other embodiments of this application; 
         FIG.  13    is a cross-sectional view of an exhaust apparatus according to yet some other embodiments of this application; 
         FIG.  14    is a cross-sectional view of an exhaust apparatus according to still some other embodiments of this application; 
         FIG.  15    is a cross-sectional view of an exhaust apparatus according to yet some other embodiments of this application; 
         FIG.  16    is a cross-sectional view of an exhaust apparatus according to still some other embodiments of this application; 
         FIG.  17    is a top view of an exhaust apparatus according to still some other embodiments of this application; 
         FIG.  18    is a cross-sectional view along direction C-C in  FIG.  17   ; 
         FIG.  19    is an enlarged view of position D in  FIG.  18   ; 
         FIG.  20    is a cross-sectional view of an exhaust apparatus according to yet some other embodiments of this application; 
         FIG.  21    is a flowchart of a manufacturing method of exhaust apparatus according to some embodiments of this application; and 
         FIG.  22    is a schematic block diagram of a manufacturing device of exhaust apparatus according to some embodiments of this application. 
     
    
    
     Reference signs in the specific embodiments are described as follows:
       1000 . vehicle;     100 . battery;  200 . controller;  300 . motor;     10 . box;  11 . first portion;  12 . second portion;     20 . battery cell;     21 . housing;     22 . electrode assembly;  221 . positive electrode tab;  222 . negative electrode tab;     23 . end cover;  231 . positive electrode terminal;  232 . negative electrode terminal;     24 . exhaust apparatus;     241 . exhaust body;  2411 . first concave portion;  2412 . shielding portion;  2413 . second through hole;  2414 . second concave portion;  2415 . avoidance space;  2416 . accommodating chamber;  2417   a . bottom wall;  2417   b . side wall;     242 . exhaust mechanism;  2421 . connection member;  2421   a . first through hole;  2421   b . connection portion;  24211 . body region;  24212 . exhaust region;  2422 . ventilation member;     243 . ventilation limiting member;     244 . insulating member;  2441 . third through hole;     2100 . providing apparatus;  2200 . assembly apparatus; X. axial direction.   

     In the accompanying drawings, the same reference signs represent the same components, and the figures are not drawn to scale. 
     DESCRIPTION OF EMBODIMENTS 
     To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the following clearly describes the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Apparently, the embodiments described are some rather than all embodiments of this application. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of this application without creative efforts shall fall within the protection scope of this application. 
     Unless otherwise defined, all technical and scientific terms used in this application shall have the same meanings as commonly understood by those skilled in the art to which this application relates. The terms used in the specification of this application are intended to merely describe the specific embodiments rather than to limit this application. The terms “include”, “comprise”, and any variations thereof in the specification and claims of this application as well as the foregoing description of drawings are intended to cover non-exclusive inclusions. In the specification, claims, or accompanying drawings of this application, the terms “first”, “second”, and the like are intended to distinguish between different objects rather than to indicate a particular order or relative importance. 
     In this application, reference to “embodiment” means that specific features, structures or characteristics described with reference to the embodiment may be incorporated in at least one embodiment of this application. The word “embodiment” appearing in various places in the specification does not necessarily refer to the same embodiment or an independent or alternative embodiment that is exclusive of other embodiments. 
     In the description of this application, it should be noted that unless otherwise specified and defined explicitly, the terms “mount”, “connect”, “join”, and “attach” should be understood in their general senses. For example, they may refer to a fixed connection, a detachable connection, or an integral connection, and may refer to a direct connection, an indirect connection via an intermediate medium, or an internal communication between two elements. A person of ordinary skills in the art can understand specific meanings of these terms in this application as appropriate to specific situations. 
     The term “and/or” in this application is only an associative relationship for describing associated objects, indicating that three relationships may be present. For example, A and/or B may indicate three cases: presence of only A; presence of both A and B; and presence of only B. In addition, the character “/” in this application generally indicates an “or” relationship between contextually associated objects. 
     In the embodiments of this application, the same reference signs denote the same components. For brevity, in different embodiments, detailed descriptions of the same components are not repeated. It should be understood that, as shown in the accompanying drawings, sizes such as thickness, length, and width of various components and sizes such as thickness, length, and width of integrated devices in the embodiments of this application are merely for illustrative purposes and should not constitute any limitations on this application. 
     In this application, “a plurality of” means more than two (inclusive). 
     In this application, the battery cell may include a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery, a magnesium-ion battery, or the like. This is not limited in the embodiments of this application. The battery cell may be cylindrical, flat, cuboid, or of other shapes, which is not limited in the embodiments of this application either. Battery cells are typically divided into three types by packaging method: cylindrical cell, prismatic cell, and pouch cell. The type of battery is not limited in the embodiments of this application either. 
     The battery mentioned in the embodiments of this application is a single physical module that includes one or more battery cells for providing a higher voltage and capacity. For example, the battery mentioned in this application may include a battery module, a battery pack, or the like. A battery typically includes a box configured to enclose one or more battery cells. The box can prevent liquids or other foreign matters from affecting charging or discharging of the battery cell. 
     The battery cell includes an electrode assembly and an electrolyte. The electrode assembly includes a positive electrode plate, a negative electrode plate, and a separator. Working of the battery cell mainly relies on migration of metal ions between the positive electrode plate and the negative electrode plate. The positive electrode plate includes a positive electrode current collector and a positive electrode active substance layer. The positive electrode active substance layer is applied on a surface of the positive electrode current collector. The part of positive electrode current collector uncoated with the positive electrode active substance layer protrudes out of the part of positive electrode current collector coated with the positive electrode active substance layer and serves as a positive electrode tab. A lithium-ion battery is used as an example, for which, the positive electrode current collector may be made of aluminum and the positive electrode active substance may be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate, or the like. The negative electrode plate includes a negative electrode current collector and a negative electrode active substance layer. The negative electrode active substance layer is applied on a surface of the negative electrode current collector. The part of negative electrode current collector uncoated with the negative electrode active substance layer protrudes out of the part of negative electrode current collector coated with the negative electrode active substance layer and serves as a negative electrode tab. The negative electrode current collector may be made of copper, and the negative electrode active substance may be carbon, silicon, or the like. To allow a large current to pass through without any fusing, multiple positive electrode tabs are provided and stacked together, and multiple negative electrode tabs are provided and stacked together. The separator may be made of PP (polypropylene, polypropylene), PE (polyethylene, polyethylene), or the like. In addition, the electrode assembly may be a winding structure or a laminated structure, but the embodiments of this application are not limited thereto. 
     For the development of battery technology, many design factors need to be considered, for example, performance parameters such as energy density, cycle life, discharge capacity, and charge and discharge rate, as well as safety of the battery. 
     In the battery cell, after many charge and discharge cycles, there are side reactions, and gas is continuously generated, such that there is a specific air pressure in the battery cell. As the air pressure increases, the gas between the electrode plates cannot be exhausted in due course, which affects intercalation and deintercalation of lithium ions, and then leads to the risk of lithium precipitation. To ensure safety performance of the battery cell, an exhaust apparatus is typically provided in the battery cell, and the gas generated inside the battery cell is exhausted through the exhaust apparatus to ensure safety performance of the battery cell. 
     The inventors found that even if an exhaust apparatus is provided in the battery cell, the risks of fire and explosion of the battery cell still occur. The inventors found through further studies that in an existing exhaust apparatus, a large through hole is generally provided on the exhaust body, and a ventilation member covers the through hole. When an air pressure in the battery cell reaches a preset threshold, the gas is exhausted from the battery cell through the ventilation member. The gas acts on the ventilation member in the exhaust process, which makes the ventilation member easy to deform, accelerates the aging of the ventilation member, and brings a safety risk to the battery cell. 
     In view of this, an embodiment of this application provides an exhaust apparatus, in which a connection member and a ventilation member are provided on an exhaust body. The connection member is configured to connect the exhaust body, and the connection member is provided with a plurality of first through holes. The ventilation member covers the plurality of first through holes, and the ventilation member is configured to, when a pressure of gas inside a battery cell reaches a first threshold, exhaust the gas to the outside of the battery cell through the plurality of first through holes. The connection member includes a connection portion formed between two adjacent ones of the first through holes, and the connection portion is configured to attach to the ventilation member to limit deformation of the ventilation member. 
     If such exhaust apparatus is applied to the battery cell, and when a pressure of gas inside a battery cell reaches a first threshold, the ventilation member exhausts the gas to the outside of the battery cell through the plurality of first through holes, so as to achieve the purpose of exhausting the gas inside the battery cell. The connection member includes the connection portion formed between two adjacent ones of the first through holes, and therefore it can be attached to the ventilation member through the connection portion. When the gas inside the battery cell is relatively high and acts on the ventilation member, the connection portion can provide the ventilation member with a counterforce against the pressure in the battery cell to reduce deformation of the ventilation member, improve the overall internal pressure resistance of the exhaust apparatus, decrease an aging rate of the ventilation member, and further enhance safety performance of the battery cell. 
     The pressure relief apparatus described in the embodiments of this application is applicable to battery cells, batteries, and electric apparatuses and devices using a battery. 
     The electric apparatus and device may be vehicles, mobile phones, portable devices, notebook computers, ships, spacecrafts, electric toys, electric tools, or the like. The vehicle may be a fossil fuel vehicle, a natural gas vehicle, or a new energy vehicle. The new energy vehicle may be a battery electric vehicle, a hybrid electric vehicle, a range-extended electric vehicle, or the like. The spacecraft includes an airplane, a rocket, a space shuttle, a spaceship, and the like. The electric toy includes a fixed or mobile electric toy, for example, a game console, an electric toy car, an electric toy ship, an electric toy airplane, and the like. The electric tool includes an electric metal cutting tool, an electric grinding tool, an electric assembly tool, and an electric railway-specific tool, for example, an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an electric impact drill, a concrete vibrator, and an electric planer. The embodiments of this application impose no special limitation on the foregoing electric device. 
     For ease of description, the electric apparatus being a vehicle is used as example for description of the following embodiments. 
     Referring to  FIG.  1   ,  FIG.  1    is a schematic structural diagram of a vehicle  1000  according to some embodiments of this application. The vehicle  1000  is provided with a battery  100  inside, where the battery  100  may be disposed at the bottom, front or rear of the vehicle  1000 . The battery  100  may be configured to supply power to the vehicle  1000 . For example, the battery  100  may be used as an operational power source for the vehicle  1000 . 
     The vehicle  1000  may further include a controller  200  and a motor  300 , where the controller  200  is configured to control the battery  100  to supply power to the motor  300 , for example, to satisfy power needs of start, navigation, and driving of the vehicle  1000 . 
     In some embodiments of this application, the battery  100  can be used as not only the operational power source for the vehicle  1000  but also a driving power source for the vehicle  1000 , replacing or partially replacing fossil fuel or natural gas to provide driving traction for the vehicle  1000 . 
     Referring to  FIG.  2   ,  FIG.  2    is a schematic structural diagram of a battery  100  according to some embodiments of this application. The battery  100  includes a box  10  and a battery cell  20 , where the box  10  is configured to accommodate the battery cell  20 . 
     The box  10  is an element for accommodating the battery cell  20 , providing an accommodating space for the battery cell  20 . The box  10  may be a variety of structures. In some embodiments, the box  10  may include a first portion  11  and a second portion  12 . The first portion  11  and the second portion  12  fit together to jointly define a space for accommodating the battery cell  20 . The first portion  11  and the second portion  12  may have a variety of shapes, for example, cuboid, cylinder, or the like. The first portion  11  may be a hollow structure with one side open, and the second portion  12  may also be a hollow structure with one side open, where the open side of the second portion  12  is engaged with the open side of the first portion  11  so as to form a box  10  having an accommodating space. Alternatively, the first portion  11  may be a hollow structure with one side open, and the second portion  12  may be a plate structure, where the second portion  12  is engaged with the open side of the first portion  11  so as to form a box  10  having an accommodating space. The first portion  11  and the second portion  12  may be sealed by a sealing element, and the sealing element may be a sealing ring, a sealing adhesive, or the like. 
     In the battery  100 , one or a plurality of battery cells  20  may be provided. If a plurality of battery cells  20  are provided, the plurality of battery cells  20  may be connected in series, in parallel, or in series-parallel, where being connected in series-parallel means a combination of series and parallel connections of the plurality of battery cells  20 . Alternatively, the plurality of battery cells  20  may be connected in series, in parallel, or in series-parallel first to form a battery module first, and then a plurality of battery modules are connected in series, in parallel, or in series-parallel to form an entirety which is accommodated in the box  10 . It is also possible that all the battery cells  20  are directly connected in series, in parallel, or in series-parallel to form an entirety which is then accommodated in the box  10 . 
     Referring to  FIG.  3   ,  FIG.  3    is an exploded view of a battery cell  20  according to some embodiments of this application. The battery cell  20  includes an end cover  23 , an electrode assembly  22 , a housing  21 , and an exhaust apparatus  24 . 
     The housing  21  is a component for accommodating the electrode assembly  22 , and the housing  21  may be a hollow structure with an opening formed at one end. The housing  21  may be in various shapes, such as cylinder and cuboid. The housing  21  may be made of various materials such as copper, iron, aluminum, steel, and aluminum alloy. 
     The electrode assembly  22  in the housing  21  may be provided in one or in plurality. For example, as shown in  FIG.  3   , there are a plurality of electrode assemblies  22 , and the plurality of electrode assemblies  22  are arranged in a stacking manner. 
     The electrode assembly  22  is a component of the battery cell  20  in which electrochemical reactions occur. The electrode assembly  22  includes a negative electrode plate, a positive electrode plate, and a separator. The electrode assembly  22  may be a winding structure formed by winding the positive electrode plate, the separator, and the negative electrode plate, or may be a stacked structure formed by stacking the positive electrode plate, the separator, and the negative electrode plate. 
     The positive electrode plate may include a positive electrode current collector and a positive electrode active substance layer coated on each of two opposite sides of the positive electrode current collector. The negative electrode plate may include a negative electrode current collector and a negative electrode active substance layer coated on each of two opposite sides of the negative electrode current collector. The electrode assembly  22  has a positive electrode tab  221  and a negative electrode tab  222 . The positive electrode tab  221  may be part of the positive electrode plate uncoated with the positive electrode active material layer, and the negative electrode tab  222   may be part of the negative electrode plate uncoated with the negative electrode active material layer. 
     The end cover  23  is a component that covers the opening of the housing  21  to isolate the internal environment of the battery cell  20  from the external environment. The end cover  23  covers the opening of the housing  21 , and the end cover  23  and the housing  21  together define a sealed space for accommodating the electrode assembly  22 , the electrolyte, and other components. A shape of the end cover  23  may match a shape of the housing  21 . For example, the housing  21  is a cuboid structure, and the end cover  23  is a rectangular plate structure that matches the housing  21 . For another example, the housing  21  is a cylinder structure, and the end cover  23  is a circular plate structure that matches the housing  21 . The end cover  23  may also be made of various materials such as copper, iron, aluminum, steel, and aluminum alloy. The end cover  23  and the housing  21  may be made of a same material or different materials. 
     An electrode terminal may be provided on the end cover  23 , and the electrode terminal is configured to electrically connect to the electrode assembly  22  so as to output electrical energy of the battery cell  20 . The electrode terminal may include a positive electrode terminal  231  and a negative electrode terminal  232 . The positive electrode terminal  231  is configured to electrically connect to the positive electrode tab  221 . and the negative electrode terminal  232  is configured to electrically connect to the negative electrode tab  222 . The positive electrode terminal  231  and the positive electrode tab  221  may be directly connected or indirectly connected, and the negative electrode terminal  232  and the negative electrode tab  222  may be directly connected or indirectly connected. 
     The exhaust apparatus  24  is a component that exhausts the gas inside the battery cell  20 , and when a pressure of gas inside the battery cell  20  reaches a first threshold, the exhaust apparatus  24  exhausts the gas inside the battery cell  20 . A specific structure of the exhaust apparatus  24  is described in detail below with reference to the accompanying drawings. 
     Referring to  FIG.  4    to  FIG.  6   ,  FIG.  4    is a top view of an exhaust apparatus  24  according to some embodiments of this application,  FIG.  5    is a cross-sectional along direction A-A in  FIG.  4   , and  FIG.  6    is an exploded view of the exhaust apparatus  24  according to some embodiments of this application. The exhaust apparatus  24  provided in this embodiment of this application is applied to the battery cell  20 , and the exhaust apparatus  24  includes an exhaust body  241  and an exhaust mechanism  242 . The exhaust mechanism  242  includes a connection member  2421  and a ventilation member  2422  that are provided on the exhaust body  241 , the connection member  2421  is configured to connect the exhaust body  241 , the connection member  2421  is provided with a plurality of first through holes  2421   a , the ventilation member  2422  covers the plurality of first through holes  2421   a , and the ventilation member  2422  is configured to, when a pressure of gas inside the battery cell  20  reaches a first threshold, exhaust the gas to the outside of the battery cell  20  through the plurality of first through holes  2421   a . The connection member  2421  includes a connection portion  2421   b  formed between two adjacent ones of the first through holes  2421   a , and the connection portion  2421   b  is configured to attach to the ventilation member  2422  to limit deformation of the ventilation member  2422 . 
     The exhaust body  241  may be a component mounted on the end cover  23 , for example, the exhaust apparatus  24  is a plate structure mounted on the end cover  23 . The entire exhaust body  241  may also be the end cover  23  for covering the electrode assembly  22 . For example, the end cover  23  is the exhaust body  241 . The exhaust body  241  may also be the housing  21  for accommodating the electrode assembly  22 . For example, the housing  21  is the exhaust body  241 , and the connection member  2421  of the exhaust mechanism  242  may be connected to the housing  21 . 
     The connection member  2421  and the exhaust body  241  may be of an integrated structure, or certainly may be of a split structure. When the split structure is used, the two may be fixedly connected by welding or the like. 
     The number of first through holes  2421   a  provided in the connection member  2421  may be two, three, or more. The specific number is not limited in this application. 
     The first through hole  2421   a  may be in a regular geometric shape, such as a circle, an ellipse, and a regular polygon. Certainly, the first through hole  2421   a  may alternatively be in an irregular geometric shape. The specific shape is not limited in this application, provided that internal gas exhaust requirements of the battery cell  20  can be met. 
     All of the first through holes  2421   a  may have a same shape. For example, the plurality of first through holes  2421   a  may all be in a circular shape, an ellipse shape, or a kidney shape. Certainly, all of the first through holes  2421   a  may be in different shapes, or at least part of the first through holes  2421   a  may be in different shapes. For example, part of the first through holes  2421   a  may be in a circular shape, and part of the first through holes  2421   a  may be in an ellipse shape, a kidney shape, or a polygon shape. 
     The first through hole  2421   a  may be formed in various ways, such as punching and milling, which is not particularly limited in the embodiments of this application. 
     The distribution pattern of the plurality of first through holes  2421   a  on the connection member  2421  is not specifically limited. For example, the plurality of first through holes  2421   a  may be distributed in rows and columns or in an array, or may be distributed in sequence along a circular track, or certainly may be distributed in sequence along a linear track or a curved track. 
     Hole walls of two adjacent ones of the first through holes  2421   a  are at least partially spaced apart, and the connection portion  2421   b  is a region where the connection member  2421  is located between two adjacent ones of the first through holes  2421   a . In any direction perpendicular to the axial direction of the first through hole  2421   a , the connection portion  2421   b  may be formed between every two adjacent ones of the first through holes  2421   a . 
     The connection portion  2421   b  is attached to the ventilation member  2422 , and the ventilation member  2422  may contact and abut against the connection portion  2421   b . The ventilation member  2422  and the connection portion  2421   b  may be connected to each other by means of bonding or chemical bonding. Deformation of the ventilation member  2422  may be caused by bulging at least partially in a direction leaving away from the electrode assembly  22 . 
     The ventilation member  2422  may be provided on a side of the connection member  2421  close to the inside of the battery cell  20 . In this case, the connection portion  2421   b  is configured to provide an anchorage force for the ventilation member  2422  when the ventilation member  2422  deforms towards the outside of the battery cell  20 . Certainly, the ventilation member  2422  may alternatively be provided on a side of the connection member  2421  far away from the inside of the battery cell  20 . In this case, the connection portion  2421   b  is configured to provide pulling stress for the ventilation member  2422  when the ventilation member  2422  deforms towards the outside of the battery cell  20 . 
     The ventilation member  2422  covers the plurality of first through holes  2421   a . Specifically, an orthographic projection of the ventilation member  2422  can cover orthographic projections of all of the first through holes  2421   a  in the axial direction X of the first through hole  2421   a . The ventilation member  2422  is configured to exhaust the gas to the outside of the battery cell  20  through the plurality of first through holes  2421   a  when the gas pressure in the battery cell  20  reaches the first threshold. 
     The ventilation member  2422  has a ventilation function, and may be made of PP (polypropylen, polypropylene), PE (polyethylene, polyethylene), PU (polyurethane, polyurethane), or the like. The gas inside the battery cell  20  needs to pass through the ventilation member  2422  when it is exhausted. The ventilation member  2422  can allow the gas inside the battery cell  20  to flow to the outside, and can block water vapor and the like outside the battery cell  20  from entering the inside of the battery cell  20 . 
     In the foregoing technical solution, the exhaust mechanism  242  includes the exhaust body  241  and the exhaust mechanism  242  provided on the exhaust body  241 . The exhaust mechanism  242  includes the connection member  2421  and the ventilation member  2422 , and the connection member  2421  is provided with the plurality of first through holes  2421   a . The ventilation member  2422  covers the plurality of first through holes  2421   a . When the pressure of the gas in the battery cell  20  reaches the first threshold, the gas is exhausted to the outside of the battery cell  20  through the ventilation member  2422  and the plurality of first through holes  2421   a , so as to achieve the purpose of exhausting the gas inside the battery cell  20 . The connection member  2421  includes the connection portion  2421   b  formed between two adjacent ones of the first through holes  2421   a , and therefore it can be attached to the ventilation member  2422  through the connection portion  2421   b . When the gas inside the battery cell  20  acts on the ventilation member  2422  in the process of exhaust to the outside of the battery cell  20  through the ventilation member  2422 , the connection portion  2421   b  can provide the ventilation member  2422  with a counterforce against the pressure in the battery cell  20  to reduce deformation of the ventilation member  2422 , improve the overall internal pressure resistance of the exhaust apparatus  24 , and further enhance safety performance of the battery cell  20 . 
     In some embodiments, the ventilation member  2422  is provided on the side of the connection member  2421  close to the inside of the battery cell  20 , and the connection portion  2421   b  is configured to provide an anchorage force for the ventilation member  2422  when the ventilation member  2422  deforms towards the outside of the battery cell  20 . 
     The side of the connection member  2421  close to the inside of the battery cell  20  may be a side of the connection member  2421  close to the inside of the battery cell  20  in the axial direction X of the first through hole  2421   a . When the ventilation member  2422  deforms towards the outside of the battery cell  20 , the connection portion  2421   b  can provide the anchorage force for the ventilation member  2422  in the axial direction X of the first through hole  2421   a  to limit deformation of the ventilation member  2422 . 
     The ventilation member  2422  is provided on the side of the connection member  2421  close to the inside of the battery cell  20 . In the exhaust process, the connection member  2421  can provide the anchorage force for the ventilation member  2422 , ensuring sufficient exhaust area, avoiding deformation or displacement of the ventilation member  2422  due to excessive pressure in the battery cell  20 , ensuring the integrity of the ventilation member  2422 , and enhancing safety performance of the ventilation member  2422 . In addition, the ventilation member  2422  is provided on the side of the connection member  2421  close to the inside of the battery cell  20 . Such position arrangement can increase the utilization of an exterior space of the end cover  23 , which is convenient for marking or implementing more functions. 
     In some embodiments, the plurality of first through holes  2421   a  have same shape and equal area. The plurality of first through holes  2421   a  may have the same shapes, for example, the plurality of first through holes  2421   a  may all be circular holes. Certainly, the plurality of first through holes  2421   a  may all be elliptical holes or polygonal holes, and optionally may be regular polygonal holes. The plurality of first through holes  2421   a  having the equal area means that any two of the first through holes  2421   a  have equal area. For example, when the plurality of first through holes  2421   a  are all circular holes, any two of the first through holes  2421   a  have equal diameter, and when all of the plurality of first through holes  2421   a  are elliptical holes, any two of the first through holes  2421   a  have equal major axes and equal minor axes. 
     The plurality of first through holes  2421   a  have same shape and equal area, which is beneficial for the gas to uniformly and quickly pass through the plurality of first through holes  2421   a  in the exhaust process. This enables the ventilation member  2422  to bear the same gas pressure as a corresponding component, avoiding deformation of the ventilation member  2422  under the action of gas due to the uneven distribution of the gas flowing through the plurality of first through holes  2421   a . Moreover, the plurality of first through holes  2421   a  may be processed by punching or milling. By making the plurality of first through holes  2421   a  have same shape and equal area, the same processing procedure may be used to process the first through holes  2421   a , which can simplify the processing procedure, reduce the machining costs, and improve the forming efficiency. 
     Still referring to  FIG.  4    to  FIG.  7   ,  FIG.  7    is a top view of the connection member  2421  of the exhaust apparatus  24  according to some embodiments of this application. In some embodiments, the plurality of first through holes  2421   a  are spaced apart from each other, and a minimum distance D between two adjacent ones of the first through holes  2421   a  and a thickness L of the ventilation member  2422  in an axial direction X of the first through hole  2421   a  satisfy 1.2≤D/L≤5. 
     The plurality of first through holes  2421   a  are spaced apart from each other, so that hole walls of two adjacent ones of the first through holes  2421   a  are spaced apart from each other. The minimum distance D between two adjacent ones of the first through holes  2421   a  may be a minimum distance between orthographic projections of the hole walls of the two adjacent ones of the first through holes  2421   a  in the axial direction X of the first through hole  2421   a . For example, a point a may be taken from an orthographic projection of one of the two adjacent ones of the first through holes  2421   a , and a point b may be taken from an orthographic projection of the other one. In line segments formed by connecting a and b, a line segment with the shortest length is the minimum distance D between the two adjacent ones of the first through holes  2421   a . 
     Through the foregoing arrangement, mechanical strength of the connection portion  2421   b  and an attachment area between the connection portion  2421   b  and the ventilation member  2422  can be ensured, and a probability of deformation of the ventilation member  2422  under the action of the pressure in the battery cell  20  is decreased. 
     In some embodiments, the first through hole  2421   a  is in one of a circular shape, an ellipse shape, a kidney shape, and a polygon shape. 
     The shape of the first through hole  2421   a  may be a shape of an orthographic projection of the first through hole  2421   a  in the axial direction X thereof, and may be in one of a circular shape, an ellipse shape, a kidney shape, and a polygon shape. The first through holes  2421   a  may all be in one of a circular shape, an ellipse shape, a kidney shape, and a polygon shape. 
     Through the foregoing arrangement, in the exhaust process, the battery cell  20  can not only ensure exhaust efficiency, but also make the first through holes  2421   a  have a regular geometric shape or an approximately regular geometric shape, which is beneficial to the processing and forming of the first through holes  2421   a . 
     In some embodiments, the first through holes  2421   a  are circular, and a bore diameter d of the first through hole  2421   a  and a minimum distance D between two adjacent ones of the first through holes  2421   a  satisfy 0.1≤d/D≤4. 
     If the bore diameter d of the first through hole  2421   a  is too small, the minimum distance D between two adjacent ones of the first through holes  2421   a  is too large, in other words, when d/D&lt;0.1, under the condition that the ventilation area remains unchanged, an area occupied by the overall distribution of the first through holes  2421   a  is too large, which is not conducive to the assembly of other components; and if the bore diameter d of the first through hole  2421   a  is too large, the minimum distance D between the two adjacent ones of the first through holes  2421   a  is too small, in other words, when d/D&gt;4, a jointing area between the connection portion  2421   b  and the ventilation member  2422  is too small, and correspondingly, connection strength therebetween is too small, which may lead to separation of the ventilation member  2422  from the connection portion  2421   b , thereby affecting the performance of the ventilation member  2422  and making the ventilation member  2422  be prone to a risk of deformation when the internal pressure of the battery cell  20  is too high. In the foregoing technical solution, the first through hole  2421   a  is circular, and the bore diameter d of the first through hole  2421   a  and the minimum distance D between the two adjacent ones of the first through holes  2421   a  satisfy 0.1≤d/D≤4, which can make a ratio of the bore diameter d of the first through hole  2421   a  to the minimum distance D between the two adjacent ones of the first through holes  2421   a  be moderate, so as to avoid excessively large area being occupied by the plurality of first through holes  2421   a  caused by the excessively large or small ratio of the two, or avoid separation of the ventilation member from the connection portion caused by insufficient attachment strength therebetween. 
     In some embodiments, the minimum distance D between two adjacent ones of the first through holes  2421   a  satisfies D≥0.5 mm. 
     If the distance between two adjacent ones of the first through holes  2421   a  is too small, the first through holes  2421   a  may be deformed or even the connection portion  2421   b  between the two adjacent ones of the first through holes  2421   a  may be broken, resulting in deformation and even failure of the ventilation member  2422 . The foregoing arrangement can ensure a larger effective contact area of a matching portion between the connection portion  2421   b  and the ventilation member  2422 , ensure the attachment strength requirements of the connection portion  2421   b  and the ventilation member  2422 , and avoid fracture and failure of the connection portion  2421   b  caused by a too small distance between the two adjacent ones of the first through holes  2421   a . 
     In some embodiments, in the axial direction of the first through hole  2421   a , a sum S1 of orthographic projection areas of all of the first through holes  2421   a  and an orthographic projection area S2 of the ventilation member  2422  satisfy S1/S2≤0.8. 
     The area of the orthographic projection of each of the first through holes  2421   a  in its own axial direction X is an area enclosed by an orthographic projection contour of the hole wall of the first through hole  2421   a  in the axial direction X. For example, when the first through hole  2421   a  is a circular hole, the orthographic projection of the first through hole  2421   a  in its own axial direction X is circular, and the area of the orthographic projection of the first through hole  2421   a  is an area of the circular inner region. When the orthographic projection of the first through hole  2421   a  in its own axial direction X is polygonal, the area of the orthographic projection of the first through hole  2421   a  is an area of the inner region of the polygon. 
     When the number of the first through holes  2421   a  is 8, the sum S1 of the areas of the orthographic projections of all of the first through holes  2421   a  is equal to a value obtained by adding areas of orthographic projections of the 8 first through holes  2421   a  in the axial direction X of the first through hole  2421   a . When the number of the first through holes  2421   a  is 16, the sum S1 of the areas of the orthographic projections of all of the first through holes  2421   a  is equal to a value obtained by adding areas of orthographic projections of the 16 first through holes  2421   a  in the axial direction X of the first through hole  2421   a . 
     In the axial direction X of the first through hole  2421   a , the area S2 of the orthographic projection of the ventilation member  2422  is greater than the sum S1 of the areas of the orthographic projections of all of the first through holes  2421   a . 
     The foregoing arrangement can ensure the effective contact area of the matching portion between the connection portion  2421   b  and the ventilation member  2422 , enhance the attachment strength between the ventilation member  2422  and the connection portion  2421   b , decrease a probability of deformation of the ventilation member  2422 , and ensure integrity and reliability of the ventilation member  2422 . 
     Still referring to  FIG.  4    to  FIG.  7   , in some embodiments, the exhaust body  241  and the exhaust mechanism  242  are provided separately, and the exhaust mechanism  242  is connected to the exhaust body  241  through the connection member  2421 . 
     The exhaust body  241  and the exhaust mechanism  242  are provided separately, that is, the exhaust body  241  and the exhaust mechanism  242  may be two independent components before they are assembled, and are produced and processed separately, and when the exhaust body  241  and the exhaust mechanism  242  are assembled together, the exhaust mechanism  242  is connected to the connection member  2421  through the exhaust body  241 . 
     In the foregoing arrangement, the exhaust body  241  and the exhaust mechanism  242  are independent components, which is convenient for processing and assembling. In addition, this separate-forming method enables the exhaust body  241  and the exhaust mechanism  242  to be processed and manufactured separately from different materials, such that an appropriate material and processing technology can be selected for the entire exhaust apparatus according to the structural characteristics and usage requirements of the exhaust mechanism  242 . 
     In some embodiments, the exhaust body  241  is provided with a first concave portion  2411 , and the first concave portion  2411  is configured to accommodate at least part of the exhaust mechanism  242 . 
     The first concave portion  2411  is formed by removing part of the material on the exhaust body  241 . In the axial direction X of the first through hole  2421   a , a thickness of a bottom wall of the first concave portion  2411  is smaller than a thickness of a corresponding another region of the exhaust body  241 . When the exhaust apparatus  24  is applied to the battery cell  20 , the first concave portion  2411  may be provided close to the electrode assembly  22 , or certainly may be provided far away from the electrode assembly  22 . 
     In the axial direction X of the first through hole  2421   a , the orthographic projection of the first concave portion  2411  may be in a circular shape, an ellipse shape, a polygon shape, or the like, which is not specifically limited in this application. 
     The exhaust mechanism  242  may be partially located in the first concave portion  2411 , or certainly the exhaust mechanism  242  may alternatively be entirely located in the first concave portion  2411 . When the exhaust mechanism  242  is entirely located in the first concave portion  2411 , in the axial direction X of the first through hole  2421   a , a side of the exhaust mechanism  242  far away from the bottom wall of the first concave portion  2411  may be flush with the exhaust body  241 . 
     The first concave portion  2411  is provided on the exhaust body  241 , and the exhaust mechanism  242  is accommodated at least partially in the first concave portion  2411 , which can reduce the occupied space of the entire exhaust apparatus  24 , and such arrangement of the first concave portion  2411  can enable positioning of the exhaust mechanism  242  for installation and reduce assembly difficulty between the exhaust mechanism  242  and the exhaust body  241 . 
     In some embodiments, the connection member  2421  includes a body region  24211  and an exhaust region  24212 . The body region  24211  is configured to connect the exhaust body  241 , the exhaust region  24212  includes the connection portion  2421   b  and the plurality of first through holes  2421   a , one part of the ventilation member  2422  is attached to the body region  24211 , and the other part of the ventilation member  2422  is attached to the connection portion  2421   b  of the exhaust region  24212 . The exhaust body  241  is provided with a shielding portion  2412  and a second through hole  2413  at the bottom of the first concave portion  2411 . The shielding portion  2412  is configured to shield at least part of the exhaust region  24212 , and the second through hole  2413  is configured to communicate with space defined by the first concave portion  2411 . 
     The body region  24211  and the exhaust region  24212  of the connection member  2421  may be of an integrated structure, or certainly may be of a split structure, and optionally they are of an integrated structure, which can ensure the connection strength between the two and facilitate the forming of the connection member  2421 . 
     The body region  24211  of the connection member  2421  may be disposed around the exhaust region  24212 , and the outer circumference of the body region  24211  may be connected to the exhaust body  241 , or optionally may be fixedly connected to the exhaust body  241  by welding or the like. 
     The plurality of first through holes  2421   a  and the connection portion  2421   b  are all provided in the exhaust region  24212 , and the ventilation member  2422  is attached to both the connection portion  2421   b  of the exhaust region  24212  and the body region  24211 . 
     The first concave portion  2411  includes a bottom and side walls, and the side walls are arranged around the bottom. The shielding portion  2412  is located at the bottom of the first concave portion  2411 , and the second through hole  2413  may run through the bottom of the first concave portion  2411  in the axial direction X of the first through hole  2421   a . 
     The number of the second through holes  2413  may be one or more, and a bore diameter of the second through hole  2413  may be equal to or not equal to the bore diameter of the first through hole  2421   a . Optionally, the bore diameter of the second through hole  2413  may be larger than that of any one of the first through holes  2421   a . 
     In the axial direction X of the first through hole  2421   a , the second through hole  2413  and the first through hole  2421   a  may be opposite, or certainly in some embodiments, may be staggered in the axial direction X of the first through hole  2421   a . 
     By defining that the connection member  2421  includes the body region  24211  and the exhaust region  24212 , the connection member  2421  can be connected to the exhaust body  241  through the body region  24211  to ensure the connection strength between the connection member  2421  and the exhaust body  241 . The gas inside the battery cell  20  can be exhausted through the exhaust region  24212  to ensure safety performance of the battery cell  20 . Because one part of the ventilation member  2422  is attached to the body region  24211  and the other part of the ventilation member  2422  is attached to the exhaust region  24212 , to be specific, the ventilation member  2422  is attached not only to the connection portion  2421   b  but also to the body region  24211 , the attachment strength between the ventilation member  2422  and the connection member  2421  can be ensured, and the risk of separation of the ventilation member  2422  from the connection member  2421  can be reduced. The shielding portion  2412  is configured to shield at least part of the exhaust region  24212 , and the shielding portion  2412  can prevent at least part of impurities from entering the plurality of first through holes  2421   a , thereby avoiding influence on the ventilation member  2422  and ensuring performance of the ventilation member  2422 . The second through hole  2413  is configured to communicate with the space defined by the first concave portion  2411 , so that the gas inside the battery cell  20  can be exhausted, so as to ensure safety performance of the battery cell  20 . 
     In some embodiments, the shielding portion  2412  is provided with a second concave portion  2414 , where the second concave portion  2414  is recessed from the bottom of the first concave portion  2411  in a direction leaving away from the ventilation member  2422 , and an avoidance space  2415  is formed between the bottom of the second concave portion  2414  and the exhaust mechanism  242  to avoid the exhaust region  24212 . 
     The orthographic projection of the second concave portion  2414  in the axial direction X of the first through hole  2421   a  may be in various shapes such as circle, ellipse, or polygon. Optionally, in the axial direction X of the first through hole  2421   a , the area of the orthographic projection of the second concave portion  2414  is smaller than an area of an orthographic projection of the first concave portion  2411 . Optionally, the orthographic projection of the second concave portion  2414  is located inside the orthographic projection of the first concave portion  2411 . 
     The second through hole  2413  may extend from the bottom of the second concave portion  2414  in the axial direction X of the first through hole  2421   a  and penetrate through the exhaust body  241 . In the axial direction X of the first through hole  2421   a , the bottom of the second concave portion  2414  is spaced apart from the exhaust mechanism  242  to form the avoidance space  2415 . 
     The shielding portion  2412  is provided with the second concave portion  2414 , and the avoidance space  2415  is formed between the bottom of the second concave portion  2414  and the exhaust mechanism  242 , so that in the axial direction of the first through hole  2421   a , when the orthographic projections of at least part of the first through holes  2421   a  are covered by the shielding portion  2412 , the shielding portion  2412  can be prevented from contacting the exhaust region  24212  of the connection member  2421 , thereby preventing the shielding portion  2412  from closing the first through holes  2421   a  covered by the shielding portion  2412 , ensuring the internal gas exhaust requirements of the battery cell  20  and enhancing safety performance of the battery cell  20 . 
     Referring to  FIG.  8   ,  FIG.  8    is a cross-sectional structural view of the exhaust apparatus  24  according to some other embodiments of this application. In some embodiments, in the axial direction X of the first through hole  2421   a , the shielding portion  2412  completely shields the exhaust region  24212 , and the second through hole  2413  is completely staggered from the exhaust region  24212 . 
     To be specific, in the axial direction X of the first through hole  2421   a , the orthographic projection of the shielding portion  2412  completely covers the orthographic projection of the exhaust region  24212 , and the orthographic projection of the second through hole  2413  is completely staggered from the orthographic projection of the exhaust region  24212 . 
     The foregoing arrangement can not only ensure the internal gas exhaust requirements of the battery cell  20  but also effectively protect the connection member  2421  and ventilation member  2422  through the shielding portion  2412 , decreasing a probability that the ventilation member  2422  is damaged or corroded by external impurities or internal electrolyte. 
     Still referring to  FIG.  4    to  FIG.  8   , in some embodiments, the first concave portion  2411  is recessed from the inner surface of the exhaust body  241  in the direction leaving away from the inside of the battery cell  20 , the shielding portion  2412  is located on the side of the exhaust mechanism  242  far away from the inside of the battery cell  20 , and the second through hole  2413  is configured to communicate an exterior space of the battery cell  20  with the first concave portion  2411 . 
     The first concave portion  2411  may be formed by recessing the inner surface of the exhaust body  241  to the outside of the battery cell  20 , and the first concave portion  2411  may be recessed in the axial direction X of the first through hole  2421   a . In the axial direction X of the first through hole  2421   a , the exhaust mechanism  242  is located between the shielding portion  2412  and the electrode assembly  22 . When the orthographic projection of the shielding portion  2412  in the axial direction X of the first through hole  2421   a  covers at least part of the first through holes  2421   a , the second concave portion  2414  is provided on the shielding portion  2412 . In this example, the second concave portion  2414  may be recessed from the bottom of the first concave portion  2411  in the axial direction X leaving away from the ventilation member  2422 , and the exhaust mechanism  242  is located between the second through hole  2413  and the electrode assembly  22 . 
     In the foregoing technical solution, the first concave portion  2411  is recessed from the inner surface of the exhaust body  241  in the direction leaving away from the inside of the battery cell  20 , the shielding portion  2412  is located on the side of the exhaust mechanism  242  far away from the inside of the battery cell  20 , and the second through hole  2413  is configured to communicate the exterior space of the battery cell  20  with the first concave portion  2411 , so that the gas inside the battery cell  20  can flow through the second through hole  2413  and the first through holes  2421   a  in sequence and be exhausted through the ventilation mechanism. The position of the shielding portion  2412  can effectively prevent external impurities from entering the first through holes  2421   a , thereby reducing the risk of damage to the ventilation member  2422 . 
     Referring to  FIG.  9    to  FIG.  11   ,  FIG.  9    is a top view of an exhaust apparatus  24  according to some other embodiments of this application,  FIG.  10    is a cross-sectional view along direction B-B in  FIG.  9   , and  FIG.  11    is an exploded view of an exhaust apparatus  24  according to some other embodiments of this application. 
     In some embodiments, the first concave portion  2411  may alternatively be recessed from an outer surface of the exhaust body  241  in the direction approaching towards the inside of the battery cell  20 , the shielding portion  2412  is located on the side of the exhaust mechanism  242  close to the inside of the battery cell  20 , and the second through hole  2413  is configured to communicate an interior space of the battery cell  20  with the first concave portion  2411 . 
     The first concave portion  2411  may be recessed from the outer surface of the exhaust body  241  toward the inside of the battery cell  20  in the axial direction X of the first through hole  2421   a . When the orthographic projection of the shielding portion  2412  in the axial direction X of the first through hole  2421   a  covers at least part of the first through holes  2421   a , the second concave portion  2414  is provided on the shielding portion  2412 . In this example, the second concave portion  2414  may be recessed from the bottom of the first concave portion  2411  in the axial direction X approaching towards the ventilation member  2422 , and the second through hole  2413  is located between the exhaust mechanism  242  and the electrode assembly  22 . 
     In the foregoing technical solution, the gas generated by the battery cell  20  first flows through the second through holes  2413 , then flows through the ventilation member  2422 , and then is exhausted through the plurality of first through holes  2421   a . The first concave portion  2411  can support and protect the ventilation member  2422  to facilitate installation and positioning of the ventilation member  2422  in  2511  of the first concave portion  2411 . 
     Referring to  FIG.  12    and  FIG.  13   ,  FIG.  12    is a cross-sectional of an exhaust apparatus  24  according to still some other embodiments of this application, and  FIG.  13    is an exploded view of an exhaust apparatus  24  according to yet some other embodiments of this application. 
     In some embodiments, the exhaust apparatus  24  further includes a ventilation limiting member  243 , where the ventilation limiting member  243  is at least partially located in the second concave portion  2414  and is configured to limit deformation of the exhaust region  24212 . 
     The ventilation limiting member  243  has a ventilation function. Optionally, the ventilation limiting member  243  may be partially located in the second concave portion  2414 , or certainly may be entirely located in the second concave portion  2414 . In the axial direction X of the first through hole  2421   a , the ventilation limiting member  243  may be held between the shielding portion  2412  and the exhaust mechanism  242 , thereby providing an anchorage force for the exhaust mechanism  242  and limiting deformation of the exhaust region  24212 , specifically, limiting deformation of the exhaust region  24212  in the axial direction X of the first through hole  2421   a . 
     Optionally, the ventilation limiting member  243  may be a film layer structure with a predetermined thickness, and optionally, the ventilation limiting member  243  may also have a waterproof function. 
     Optionally, the ventilation limiting member  243  may be in contact with but not connected to the exhaust mechanism  242  and the shielding portion  2412 , or certainly the ventilation limiting member  243  may alternatively be in contact with and connected to the exhaust mechanism  242 , or the ventilation limiting member  243  may alternatively be in contact with and connected to both the exhaust mechanism  242  and the shielding portion  2412 . 
     The exhaust apparatus  24  further includes the ventilation limiting member  243 , and the ventilation limiting member  243  is at least partially located in the second concave portion  2414 , which can provide support for the exhaust mechanism  242  through the ventilation limiting member  243  to limit deformation of the exhaust region  24212 , thereby decreasing a probability of deformation of the ventilation member  2422  and improving safety performance of the exhaust apparatus  24 . 
     In some embodiments, the ventilation limiting member  243  is attached to the exhaust region  24212  and supported on the exhaust region  24212 . 
     The ventilation limiting member  243  is attached to the exhaust region  24212 , which can cover the first through holes  2421   a  of the exhaust region  24212  and abut against the connection portion  2421   b . The ventilation limiting member  243  and the exhaust region  24212  may be directly connected to each other by means of bonding, chemical bonding, or the like. 
     The foregoing arrangement can enhance air pressure resistance of the exhaust region  24212 , decrease a probability of deformation of the exhaust region  24212 , and further decrease a probability of deformation of a region to which the ventilation member  2422  is attached. 
     In some embodiments, in the axial direction X of the first through hole  2421   a , the ventilation limiting member  243  may cover the plurality of first through holes  2421   a  and the connection portion  2421   b . 
     The foregoing arrangement can not only limit deformation of the exhaust region  24212 , but also can provide protection for the side of the ventilation member  2422  in the axial direction X, so as to prevent external impurities or internal electrolyte from acting on the ventilation member  2422  and causing damage to the ventilation member  2422 , thereby ensuring safety performance of the exhaust mechanism  242   
     In some embodiments, the ventilation member  2422  and the connection member  2421  are integrally connected by chemical bonding. 
     A chemical bond is a general term for a strong interaction force between two or more adjacent atoms (or ions) in a pure substance molecule or a crystal. An action force that binds ions or atoms together is known as a chemical bond. 
     The ventilation member  2422  and the connection member  2421  are integrally connected by chemical bonding, which makes connection between the ventilation member  2422  and the connection member  2421  more secure, ensures the connection strength of the two, minimizes influence on the performance of the ventilation member  2422 , and can guarantee the performance of the ventilation member  2422 . 
     Referring to  FIG.  14    and  FIG.  15   ,  FIG.  14    is a cross-sectional of an exhaust apparatus  24  according to still some other embodiments of this application, and  FIG.  15    is an exploded view of an exhaust apparatus  24  according to yet some other embodiments of this application. 
     In some embodiments, the exhaust apparatus  24  further includes an insulating member  244 , where the insulating member  244  is located on a side of the exhaust body  241  close to the inside of the battery cell  20 , the insulating member  244  is provided with a third through hole  2441 , and the third through hole  2441  is configured to communicate the interior space of the battery cell  20  with the first through holes  2421   a . 
     The insulating member  244  is a component that separates the end cover  23  from the electrode assembly  22 , and the insulating member  244  implements insulative isolation between the end cover  23  and the electrode assembly  22 . The insulating member  244  is made of an insulating material, and the insulating member  244  may be made of an insulating material such as plastic and rubber. For example, the insulating member  244  is provided between the end cover  23  and the electrode assembly  22 . It can be understood that if there are a plurality of electrode assemblies  22 , the insulating member  244  covers all of the plurality of electrode assemblies  22 . 
     The insulating member  244  may be a plate. In the axial direction X of the first through hole  2421   a , the third through hole  2441  may be arranged corresponding to or not corresponding to the first through hole  2421   a , and a bore diameter of the third through hole  2441  may be equal to or not equal to that of the first through hole  2421   a . 
     Provision of the insulating member  244  can avoid short circuit caused by contact between the electrode assembly  22  and the end cover  23  metal, and the third through hole  2441  provided on the insulating member  244  can communicate the interior space of the battery cell  20  with the first through holes  2421   a , ensuring the internal gas exhaust requirements of the battery cell  20 . 
     Referring to  FIG.  16   ,  FIG.  16    is a cross-sectional view of an exhaust apparatus  24  according to still some other embodiments of this application. In some embodiments, in the axial direction of the first through hole  2421   a , the third through hole  2441  is completely staggered from the first through hole  2421   a . In the axial direction X of the first through hole  2421   a , the third through hole  2441  and the first through hole  2421   a  do not overlap. 
     The foregoing arrangement can block liquid or impurity particles, thereby ensuring the performance of the ventilation member  2422 . In addition, the foregoing arrangement can also prevent the gas inside the battery cell  20  from directly acting on the first through holes  2421   a  via the third through hole  2441 , reducing the impact force on the first through holes  2421   a , decreasing a probability of deformation of the ventilation member  2422 , and further ensuring safety performance of the battery cell  20 . 
     Referring to  FIG.  17    to  FIG.  19   ,  FIG.  17    is a top view of an exhaust apparatus  24  according to still some other embodiments of this application,  FIG.  18    is a cross-sectional view along direction C-C in  FIG.  17   , and  FIG.  19    is an exploded view of position D shown in  FIG.  18   . 
     In some embodiments, the exhaust body  241  is the end cover  23  of the battery cell  20 . To be specific, the exhaust apparatus  24  may be provided at a position of the end cover  23  of the battery cell  20 . 
     The foregoing arrangement can enable the end cover  23  of the battery cell  20  to be integrated with an exhaust function, which can ensure safety performance of the battery cell  20 . 
     It can be understood that, the foregoing embodiments are all illustrated by using the exhaust body  241  as the end cover  23  of the battery cell  20  as an example. 
     Referring to  FIG.  20   ,  FIG.  20    is a cross-sectional view of an exhaust apparatus  24  according to yet some other embodiments of this application. In some other embodiments, the exhaust body  241  may also be internally formed with an accommodating chamber  2416 , the exhaust body  241  has a plurality of walls defining the accommodating chamber  2416 , and the exhaust mechanism  242  is provided on at least one of the walls. 
     At least one of the walls of the exhaust body  241  is provided with an exhaust structure, and only one of the walls may be provided with an exhaust structure, or some of the walls each may be provided with an exhaust structure. The exhaust structure may be provided on an outer surface of the wall, or may be provided on an inner surface of the wall. 
     The exhaust body  241  may be in various shapes such as a cuboid and a cylinder. The exhaust body  241  being in a cuboid shape is used as an example. The exhaust body  241  may have five walls, one bottom wall  2417   a  and four side walls  2417   b  enclose together to form the accommodating chamber  2416  with an opening formed at an end, and an exhaust structure is provided on the bottom wall  2417   a . The exhaust body  241  being in a cylinder shape is used as an example. The exhaust body  241  may have two walls, one bottom wall  2417   a  and one peripheral wall. A peripheral wall encloses an edge of the bottom wall  2417   a , and the peripheral wall and the bottom wall  2417   a  enclose together to form the accommodating chamber  2416  with an opening formed at an end, and the exhaust body  241  is provided on the bottom wall  2417   a . 
     In this embodiment, because the accommodating chamber  2416  for accommodating the electrode assembly  22  is formed inside the exhaust body  241 , and the plurality of walls of the exhaust body  241  define the accommodating chamber  2416 , so that the exhaust apparatus  24  is the housing  21  capable of accommodating the electrode assembly  22 , and the exhaust apparatus  24  integrate both accommodating function and pressure relief function. 
     An embodiment of this application provides a battery cell  20 , including the exhaust apparatus  24  according to any one of the foregoing embodiments. 
     An embodiment of this application provides a battery, including a box and the battery cell  20  according to any one of the foregoing embodiments, where the box is configured to accommodate the battery cell  20 . 
     An embodiment of this application provides an electric apparatus, including the battery according to any one of the foregoing embodiments, where the battery is configured to supply electric energy. 
     Referring to  FIG.  21   ,  FIG.  21    is a flowchart of a manufacturing method of exhaust apparatus  24  according to some embodiments of this application. An embodiment of this application provides a manufacturing method of exhaust apparatus  24 , where the method includes the following steps. 
     S 100 : Provide an exhaust body  241 . 
     S 200 : Provide an exhaust mechanism  242  and connect the exhaust mechanism  242  and the exhaust body  241 . 
     The exhaust mechanism  242  includes a connection member  2421  and a ventilation member  2422 . The connection member  2421  is configured to connect the exhaust body  241 , and the connection member  2421  is provided with a plurality of first through holes  2421   a . The ventilation member  2422  covers the plurality of first through holes  2421   a , and the ventilation member  2422  is configured to, when a pressure of gas inside the battery cell  20  reaches a first threshold, exhaust the gas to the outside of the battery cell  20  through the plurality of first through holes  2421   a . The connection member  2421  includes a connection portion  2421   b  formed between two adjacent ones of the first through holes  2421   a , and the connection portion  2421   b  is configured to attach to the ventilation member  2422  to limit deformation of the ventilation member  2422 . 
     The manufacturing method of exhaust apparatus  24  provided in this embodiment of this application can be used for molding the exhaust apparatus  24  provided in the foregoing embodiments. In the exhaust apparatus  24  manufactured by using this method, the connection member  2421  includes the connection portion  2421   b  formed between two adjacent ones of the first through holes  2421   a , and therefore it can be attached to the ventilation member  2422  through the connection portion  2421   b . When the gas inside the battery cell  20  acts on the ventilation member  2422  in the process of exhaust to the outside of the battery cell  20  through the ventilation member  2422 , the connection portion  2421   b  can provide the ventilation member  2422  with a counterforce against the pressure in the battery cell  20  to reduce deformation of the ventilation member  2422 , improve the overall internal pressure resistance of the exhaust apparatus  24 , and further enhance safety performance of the battery cell  20 . 
     Referring to  FIG.  22   ,  FIG.  22    is a schematic block diagram of a manufacturing device of exhaust apparatus  24  according to some embodiments of this application. An embodiment of this application provides a manufacturing device of exhaust apparatus  24 , where the device includes a providing apparatus  2100  and an assembly apparatus  2200 . The providing apparatus  2100  is configured to provide an exhaust body  241 ; and the assembly apparatus  2200  is configured to provide an exhaust mechanism  242 , and connect the exhaust mechanism  242  to the exhaust body  241 , where the exhaust mechanism  242  includes a connection member  2421  and a ventilation member  2422 , the connection member  2421  is configured to connect the exhaust body  241 , the connection member  2421  is provided with a plurality of first through holes  2421   a , the ventilation member  2422  covers the plurality of first through holes  2421   a , and the ventilation member  2422  is configured to, when a pressure of gas inside the battery cell  20  reaches a first threshold, exhaust the gas to the outside of the battery cell  20  through the plurality of first through holes  2421   a ; and the connection member  2421  includes a connection portion  2421   b  formed between two adjacent ones of the first through holes  2421   a , and the connection portion  2421   b  is configured to attach to the ventilation member  2422  to limit deformation of the ventilation member  2422 . 
     The manufacturing device of exhaust apparatus  24  provided in this embodiment of this application can be configured to manufacture the exhaust apparatus  24  provided in the foregoing embodiments. In the exhaust apparatus  24  manufactured by using this method, the connection member  2421  includes the connection portion  2421   b  formed between two adjacent ones of the first through holes  2421   a , and therefore it can be attached to the ventilation member  2422  through the connection portion  2421   b . When the gas inside the battery cell  20  acts on the ventilation member  2422  in the process of exhaust to the outside of the battery cell  20  through the ventilation member  2422 , the connection portion  2421   b  can provide the ventilation member  2422  with a counterforce against the pressure in the battery cell  20  to reduce deformation of the ventilation member  2422 , improve the overall internal pressure resistance of the exhaust apparatus  24 , and further enhance safety performance of the battery cell  20 . 
     It should be noted that, in absence of conflicts, the embodiments and features in the embodiments in this application may be mutually combined. 
     The foregoing embodiments are only intended to illustrate the technical solutions of this application which are not intended to limit this application. Persons skilled in the art understand that this application may have various modifications and variations. Any modifications, equivalent replacements, and improvements made without departing from the spirit and principle of this application shall fall within the protection scope of this application.