Patent Publication Number: US-2022233899-A1

Title: Fire-fighting apparatus, box assembly, battery, power consumption apparatus, and method for preparing battery

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of International Application No. PCT/CN2020/129433, filed on Nov. 17, 2020, the disclosure of which is hereby incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present application relates to the technical field of battery safety, and in particular, to a fire-fighting apparatus, a box assembly, a battery, a power consumption apparatus, and a method for preparing a battery. 
     BACKGROUND 
     As an energy storage device, a battery is a core component of a hybrid vehicle and an electric vehicle. When the battery is overcharged or over-discharged or short-circuited, thermal runaway occurs, and a combustible gas emitted may explode and cause a fire. Therefore, fireproofing processing requires to be performed on the battery. 
     SUMMARY 
     The present application aims to provide a fire-fighting apparatus, a box assembly, a battery, a power consumption apparatus, and a method for preparing a battery, so as to reduce the risk of open flames when thermal runaway occurs in the battery. 
     In a first aspect, an embodiment of the present application provides a fire-fighting apparatus configured for a battery, including: a pipe, a gas release mechanism, and a blocking structure. The pipe has an air inlet end and an air outlet end, and the air inlet end is configured to be connected to a box of the battery, so that a combustible gas generated in the battery during thermal runaway events is capable of entering the pipe from the box via the air inlet end and being discharged from the pipe via the air outlet end; and the gas release mechanism is configured to be connected to the pipe, and the gas release mechanism is configured to release a fire-fighting gas into the pipe when thermal runaway occurs in the battery; where a blocking structure is provided in the pipe, and the blocking structure is configured to block the combustible gas and the fire-fighting gas and change a flow direction, so that the combustible gas and the fire-fighting gas are capable of being mixed before being discharged from the pipe. 
     In the forgoing technical solution, when thermal runaway occurs in a battery, a combustible gas inside a box enters a pipe via an air inlet end of the pipe, so that an air pressure inside the box of the battery is reduced, and an explosion caused by excessive air pressure inside the box is avoided. In addition, a fire-fighting gas is produced, which quickly fills the pipe, and drives the combustible gas to be discharged from an air outlet end of the pipe after being mixed with the combustible gas. Therefore, it is possible to provide a barrier between the outside air and the combustible gas discharged from the box. 
     Furthermore, a blocking structure allows the fire-fighting gas and the combustible gas to mix in the pipe, to reduce the concentration of the combustible gas in the pipe, so that the mixed gas discharged from the air outlet end of the pipe is not easy to catch fire or explode when it comes into contact with air. In addition, the fire-fighting gas is also beneficial for lowering a temperature of the combustible gas, thereby further preventing the occurrence of open flames. 
     Therefore, the fire-fighting apparatus provided by the foregoing solution of the present application could reduce the risk of open flames when thermal runaway occurs in the battery, while suppressing the spread of thermal runaway in the battery, which extends the safety evacuation time of a person, and achieves the purpose of fire prevention and safety protection. 
     In some embodiments of the present application, the blocking structure is configured to make a flow path of at least part of a gas in the pipe a meandering shape. 
     In the foregoing technical solution, advantages of a gas traveling in the pipe in a meandering manner are as follows: on one hand, a mixing path of the fire-fighting gas and the combustible gas can he extended, and a mixing time of the fire-fighting gas and the combustible gas can be increased, thereby improving the mixing effect of the two; on another hand, traveling in a meandering manner intensifies the colliding and mixing of the fire-fighting gas and the combustible gas, thereby improving the mixing effect of the two and reducing the situation of the occurrence of fire due to the excessive-high local concentration of the combustible gas discharged from the pipe. 
     In some embodiments of the present application, a projection of the blocking structure in an extension direction of the pipe covers a projection of a cavity of the pipe in the extension direction of the pipe. 
     In the foregoing technical solution, a projection of the blocking structure in an extension direction of the pipe covers a projection of a cavity (that is, an internal passage) of the pipe in the extension direction of the pipe, so that the combustible gas discharged from the box and the fire-fighting gas both in the pipe flow through the blocking structure and travel in a meandering manner rather than in a straight line. 
     In some embodiments of the present application, the blocking structure includes a plurality of baffle plates, the plurality of baffle plates are arranged at interval in an extension direction of the pipe, and the baffle plate is provided with an opening for a gas to pass through, or the baffle plate encloses with an inner wall of the pipe to form an opening for a gas to pass through, where projections of two adjacent openings in the extension direction of the pipe are disposed to be misaligned. 
     In the foregoing technical solution, when the gas flows through a plurality of baffle plates, a flow path of the gas is a meandering path. In addition, the baffle plate can not only mix gases, but also prevent a high-temperature particle entering the pipe from the box from flowing out of the pipe, thereby avoiding risks that may be caused by the outflow of the high-temperature particle, such as causing a fire. 
     In some embodiments of the present application, the plurality of baffle plates at least includes a pair of arc-shaped plates, and concave surfaces of the pair of arc-shaped plates are disposed opposite to each other. 
     In the foregoing technical solution, since concave surfaces of a pair of arc-shaped plates are disposed opposite to each other, when a gas enters an interval of the pair of arc-shaped plates, a concave surface of one arc-shaped plate of the pair of arc-shaped plates can guide the gas toward the other arc-shaped plate, which could intensify the collision of gases between the pair of arc-shaped plates and increase the mixing time of the gases, and thus it is beneficial for a full mixing of the fire-fighting gas and the combustible gas. 
     In some embodiments of the present application, the blocking structure includes a spiral blade, and a centerline of the spiral blade coincides with or is parallel to a central axis of the pipe. 
     In the foregoing technical solution, the spiral blade can make a flow path of the mixed gas a spiral shape, which is beneficial for full mixing of the fire-fighting gas and the combustible gas. 
     In some embodiments of the present application, the blocking structure includes a plurality of spiral blades, the plurality of spiral blades are arranged in an extension direction of the pipe, and directions of rotation of two adjacent spiral blades are opposite. 
     In the foregoing technical solution, spiral blades with two different directions of rotation may change a direction of rotation of the gas, which could further enhance the effect of mixing the gases. 
     In some embodiments of the present application, the gas release mechanism is installed at the pipe. 
     In the foregoing technical solution, it is beneficial for shortening the time for the fire-fighting gas to enter the pipe, and an intermediate connector between the gas release mechanism and the pipe is omitted, which could simplify the structure and save the cost. 
     In some embodiments of the present application, an installation position of the gas release mechanism while compared with the blocking structure, is closer to the air inlet end. 
     In the foregoing technical solution, it is beneficial for mixing the fire-fighting gas and the combustible gas, thereby ensuring the mixing effect of the blocking structure on the fire-fighting gas and combustible gas. 
     In some embodiments of the present application, the gas release mechanism is provided outside the pipe, a through hole is provided on a wall of the pipe, and the gas release mechanism is connected to the through hole, to release the fire-fighting gas into the pipe through the through hole. 
     In some embodiments of the present application, the through hole is multiple in quantity, and the multiple through holes are arranged at interval in an extension direction of the pipe. 
     In the foregoing technical solution, multiple through holes may ensure a rapid release of a sufficient amount of fire-fighting gas, thereby ensuring the reliability of fire prevention. 
     In some embodiments of the present application, the gas release mechanism includes: a fire-fighting medium, a housing, and a closure member. The fire-fighting medium is the fire-fighting gas, or, a fire-fighting solid or a fire-fighting liquid capable of generating the fire-fighting gas; the housing is configured to accommodate the fire-fighting medium, and the housing is connected to the through hole and is provided with an air outlet hole; and the closure member is configured to close the air outlet hole, and the closure member is configured to be capable of releasing closure of the air outlet hole when thermal runaway occurs in the battery, so that the fire-fighting gas enters the pipe through the air outlet hole. 
     In some embodiments of the present application, the fire-fighting medium is the fire-fighting solid or the fire-fighting liquid, and the gas release mechanism further includes a trigger, the trigger is configured to trigger the fire-fighting solid or the fire-fighting liquid when thermal runaway occurs in the battery to generate the fire-fighting gas, and the closure member is configured to be capable of opening the air outlet hole when an air pressure in the housing reaches a first threshold to release the fire-fighting gas. 
     In some embodiments of the present application, the fire-fighting medium is the fire-fighting liquid or the fire-fighting gas capable of generating the fire-fighting gas, and the fire-fighting liquid or the fire-fighting gas is encapsulated in the housing, and when the air outlet hole is enclosed by the closure member, a pressure in the housing is larger than a pressure in the pipe, and the closure member is a valve. 
     In some embodiments of the present application, a length of the pipe is 50-200 cm. 
     In the foregoing technical solution, advantages of setting the length of the pipe within such a range are as follows: first, it facilitates the installation of the gas release mechanism, which is beneficial for the installation of a plurality of gas release mechanisms; second, a distance for lowering a temperature is increased, so that the mixed gas of the fire-fighting gas and the combustible gas has a sufficient distance for lowering a temperature, and thus the possibility of catching a fire at the air outlet end of the pipe is reduced; and third, a distance for exchanging the oxygen is increased, so that a high-temperature region near the box becomes an oxygen-deficient region, thereby reducing the risk of open flames in the high-temperature region. 
     In some embodiments of the present application, the fire-fighting apparatus further includes a gas collection device, and the gas collection device is hermetically connected to the air outlet end to collect a gas discharged from the air outlet end. 
     In the foregoing technical solution, a gas collection device is provided, which could prevent the mixed gas from being directly discharged to the external environment and polluting the environment 
     In a second aspect, an embodiment of the present application provides a box assembly, including: a box, a pressure relief mechanism, and the fire-fighting apparatus provided according to the embodiment of the first aspect; the box is configured to accommodate a battery cell; the fire-fighting apparatus is provided outside the box, and the air inlet end of the fire-fighting apparatus is connected to the box; and the pressure relief mechanism is configured to be actuated when an air pressure or temperature in the box reaches a second threshold, so that a combustible gas in the box is capable of entering the pipe from the air inlet end. 
     In some embodiments of the present application, the pressure relief mechanism is provided on the box, and the air inlet end is provided on the pressure relief mechanism while covering it. 
     In a third aspect, an embodiment of the present application provides a battery, including a battery cell, and the box assembly provided according to the embodiment of the second aspect; and the battery cell is provided in the box. 
     In a fourth aspect, an embodiment of the present application provides a power consumption apparatus, including the battery provided by the third aspect. 
     In a fifth aspect, a method for producing a battery is provided, including providing a battery cell; providing a box; providing a fire-fighting apparatus, the fire-fighting apparatus including: a pipe and a gas release mechanism, the pipe having an air inlet end and an air outlet end, and the air inlet end being configured to be connected to the box, so that a combustible gas generated in the battery during thermal runaway events in the battery is capable of entering the pipe from the box via the air inlet end and being discharged from the pipe via the air outlet end; and the gas release mechanism being connected to the pipe, and the gas release mechanism being configured to release a fire-fighting gas into the pipe when thermal runaway occurs in the battery; where a blocking structure is provided in the pipe, and the blocking structure is configured to block the combustible gas and the fire-fighting gas and change a flow direction, so that the combustible gas and the fire-fighting gas are capable of being mixed before being discharged from the pipe; disposing the battery cell in the box; and disposing the fire-fighting apparatus outside the box, and connecting the air inlet end to the box. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       To describe the technical solutions in the embodiments of the present application more clearly, the following briefly introduces accompanying drawings required for describing the embodiments. it should be understood that the following accompanying drawings only show some of the embodiments of the present application, and thus should not be regarded as limitation on the scope; and a person of ordinary skill in the art may still derive other drawings from these accompanying drawings without creative efforts. 
         FIG. 1  is a schematic diagram of a vehicle provided by an embodiment of the present application; 
         FIG. 2  is an exploded schematic diagram of a battery provided by an embodiment of the present application; 
         FIG. 3  is a schematic diagram of a three-dimensional structure of a box assembly provided by an embodiment of the present application, where an upper cover body is not shown; 
         FIG. 4  is a schematic front view of a box assembly provided by an embodiment of the present application, where an upper cover body is not shown; 
         FIG. 5  is a schematic diagram of a three-dimensional structure of a fire-fighting apparatus provided by an embodiment of the present application; 
         FIG. 6  is a schematic left view of a fire-fighting apparatus provided by an embodiment of the present application; 
         FIG. 7  is a schematic cross-sectional landscape diagram of a fire-fighting apparatus provided by an embodiment of the present application, where a gas release mechanism is not shown; 
         FIG. 8  is a schematic cross-sectional landscape diagram of a fire-fighting apparatus provided by an embodiment of the present application; 
         FIG. 9  is a schematic cross-sectional landscape diagram of a fire-fighting apparatus provided by another embodiment of the present application; 
         FIG. 10  is a schematic cross-sectional landscape diagram of a fire-fighting apparatus provided by yet another embodiment of the present application; 
         FIG. 11  is a schematic diagram of a three-dimensional structure of a blocking structure of a fire-fighting apparatus provided by an embodiment of the present application, where a plurality of baffles are shown; 
         FIG. 12  is a schematic perspective view of a three-dimensional structure of a fire-fighting apparatus provided by an embodiment of the present application, where a C-shaped plate is shown; 
         FIG. 13  is a schematic cross-sectional diagram of a fire-fighting apparatus in an extension direction of a pipe provided by another embodiment of the present application, where a spherical plate is shown; 
         FIG. 14  is an enlarged schematic diagram of part A in  FIG. 13 ; 
         FIG. 15  is a schematic cross-sectional diagram of a fire-fighting apparatus in are extension direction of a pipe provided by an embodiment of the present application, where a spiral blade is shown and cross-sectional processing is not performed on a gas release mechanism; 
         FIG. 16  is a schematic diagram of a three-dimensional structure of a blocking structure provided by an embodiment of the present application, where a spiral blade is shown; 
         FIG. 17  is a schematic cross-sectional diagram of a fire-fighting apparatus in an extension direction of a pipe provided by an embodiment of the present application, where a spiral blade and a baffle are shown, and cross-sectional processing is not performed on a gas release mechanism; 
         FIG. 18  is a schematic cross-sectional diagram of a fire-fighting apparatus in an extension direction of a pipe provided by an embodiment of the present application, where a convex part is shown; 
         FIG. 19  is a schematic front view of a fire-fighting apparatus provided by an embodiment of the present application; 
         FIG. 20  is a schematic diagram of a three-dimensional structure of a fire-fighting apparatus provided by an embodiment of the present application, where a gas release mechanism is not shown; 
         FIG. 21  is a schematic front view of a fire-fighting apparatus provided by an embodiment of the present application, where a gas collection device is shown; 
         FIG. 22  is a schematic cross-sectional diagram of a gas release mechanism of a fire-fighting apparatus provided by an embodiment of the present application; 
         FIG. 23  is a schematic bottom view of a gas release mechanism of a fire-fighting apparatus provided by an embodiment of the present application; 
         FIG. 24  is a schematic diagram of a three-dimensional structure of a gas release mechanism of a fire-fighting apparatus provided by another embodiment of the present application; 
         FIG. 25  is a schematic front view of a gas release mechanism of a fire-fighting apparatus provided by another embodiment of the present application; and 
         FIG. 26  is a schematic flowchart of a method for preparing a battery provided by an embodiment of the present application. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     To describe the technical solutions in the embodiments of the present application more clearly, the following briefly introduces accompanying drawings required for describing the embodiments. It should be understood that the following accompanying drawings only show some of the embodiments of the present application, and thus should not he regarded as limitation on the scope; and a person of ordinary skill in the art may still derive other drawings from these accompanying drawings without creative efforts. 
     To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the following clearly and completely describes the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are merely some but not all of the embodiments of the present application. Generally, components of the embodiments of the present application described and illustrated in the accompanying drawings herein may be arranged and designed in various different configurations. 
     Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the protection scope of the present application, but only represents the selected embodiment of the present application. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present application without creative efforts shah fall within the protection scope of the present application. 
     It shall be noted that the embodiments of the present application and the characteristics in the embodiments may be combined with each other in the case of no conflict. It should be noted that similar reference signs and letters indicate similar items in the following accompanying drawings. Therefore, once a certain item is defined in one drawing, it is not necessary to further define and explain it in the following accompanying drawings. 
     In the description of the embodiments of the present application, it should be noted that the indication of orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship usually placed when the product of the present application is used, or the orientation or positional relationship commonly understood by a person of skilled in the art, which is merely for convenience of describing the present application and for simplifying the description, rather than for indicating or implying that an apparatus or element indicated must have a specific orientation, and must be constructed and operated in a specific orientation, which thus may not be understood as limitation to the present application. In addition, the terms “first”, “second”, and “third” are only used to distinguish descriptions, and shall not be understood as an indication or implication of relative importance. 
     In the description of the present invention, it should also be noted that unless otherwise explicitly specified and defined, the terms “disposing”, “mounting”, “connecting” and “connection” should be understood in a broad sense, for example, they may be a fixed connection, a detachable connection, or an integrated connection, may be a mechanical connection, or may be an electrical connection, may be a direct connection and may also be an indirect connection via an intermediate medium, or may be communication between the interiors of two elements. A person of ordinary skill in the art may appreciate the specific meanings of the foregoing terms in the present application according to specific conditions. 
     In addition, the battery mentioned in the embodiment of the present application refers to a single physical module that includes one or more battery cells to provide a higher voltage and capacity. For example, the battery mentioned in the present application may include a battery pack or a battery module. The battery generally includes a box for enclosing one or more battery cells. The box may prevent a liquid or other foreign matters from affecting the charging or discharging of the battery cell. 
     A plurality of battery cells are connected in series and/or in parallel via a bus component to be applied to various applications. In some high-power applications such as electric vehicles, there are generally three levels: a battery cell, a battery module, and a battery pack. The battery module is to electrically connect a certain number of battery cells together. The battery pack is composed of one or more battery modules in a sealed box, and the battery pack is connected to a chassis of the electric vehicle through the box. 
     A 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 or a magnesium-ion battery, etc., which is not limited by the embodiments of the present application. The battery cell may be cylindrical, flat, cuboid or another shape, which is also not limited by the embodiments of the present application. The battery cell is generally divided into three types according to the way of packaging: a cylindrical battery cell, a prismatic battery cell and a pouch battery cell, which is not limited by the embodiments of the present application. 
     The battery cell includes an electrode assembly and an electrolytic solution, and the electrode assembly is composed of a positive electrode sheet, a negative electrode sheet and an isolation film. The operation of the battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet includes a positive electrode current collector and a positive active material layer. The positive active material layer is coated on a surface of the positive electrode current collector, and the current collector not coated with the positive active material layer protrudes from the current collector coated with the positive active material layer and is used as a positive electrode tab. Taking a lithium-ion battery as an example, the material of the positive electrode current collector may be aluminum and the positive active material may be lithium cobalt oxides, lithium iron phosphate, ternary lithium or lithium manganate, or the like. The negative electrode sheet includes a negative electrode current collector and a negative active material layer. The negative active material layer is coated on a surface of the negative electrode current collector, and the current collector not coated with the negative active material layer protrudes from the current collector coated with the negative active material layer and is used as a negative electrode tab. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon or silicon, etc. In order to ensure that no fusing occurs when a large current passes, there are a plurality of positive electrode tabs which are stacked together, and there are a plurality of negative electrode tabs which are stacked together. A material of the isolation film/ may be PP (polypropylene), PE (polyethylene: or the like. In addition, the electrode assembly may have a winding structure or a laminated structure, and the embodiments of the present application are not limited thereto. 
     The development of the battery technology must consider many design factors at the time, such as energy density, cycle life. discharge capacity, C-rate and other performance parameters. In addition, the safety of the battery should also be considered. 
     During the use of the battery, due to short circuit, overcharge, collision and other reasons, a large amount of gas may be generated and the temperature may rise rapidly inside the battery cell in a short time, which may eventually cause explosion and fire of the battery cell, resulting in safety risks. In order to solve this problem, a pressure relief mechanism is usually provided on the battery cell. When the pressure relief mechanism is actuated, high-temperature and high-pressure substances inside the battery cell as emissions are discharged outwards from an actuated position, that is, into the battery box. In this way, the pressure and temperature in the battery cell may be relieved in the case of a controllable pressure or temperature, thereby avoiding potentially more serious accidents. However, when there are too many high-temperature and high-pressure substances discharged from the battery cell into the box, there is also a possibility of explosion and fire after the internal pressure or temperature of the box of the battery reaches a certain value. Therefore, a pressure relief mechanism is also provided on the box of the battery, to control the internal pressure or temperature of the box. 
     The pressure relief mechanism refers to an element or component that is actuated to relieve an internal pressure or temperature when the internal pressure or temperature of the battery cell or box where it is located reaches a predetermined threshold. The threshold design varies according to different design requirements, and the threshold of the pressure relief mechanism on the battery cell may depend on the material of one or more of the positive electrode sheet, the negative electrode sheet, the electrolytic solution and the isolation film in the battery cell. The threshold of the pressure relief mechanism on the box of the battery may depend on the number of battery cells inside the box, the material of one or more of the positive electrode sheet, the negative electrode sheet, the electrolytic solution and the isolation film in each battery cell, and the material of the box itself. 
     The pressure relief mechanism may take the form of an explosion-proof valve, an air valve, a pressure relief valve or a safety valve, etc., and may specifically adopt a pressure-sensitive or temperature-sensitive element or structure. That is, when the internal pressure or temperature of the battery cell or box where the pressure relief mechanism is located reaches a predetermined threshold, the pressure relief mechanism performs an action or a weakened structure provided in the pressure relief mechanism is damaged, so as to form an opening or channel for relieving the internal pressure or temperature. 
     The “actuation” mentioned in the present application means that the pressure relief mechanism acts or is activated to a certain state, such that the internal pressure and temperature of the battery cell or box can be relieved. The action generated by the pressure relief mechanism may include but be not limited to: at least a portion of the pressure relief mechanism being fractured, broken, torn or opened, and so on. 
     The emissions mentioned in the present application include but are not limited to: the electrolytic; solution, high-temperature particles (such as the dissolved or split positive and negative electrode sheets, or fragments of the isolation film), high-temperature and high-pressure gases generated by reaction such as combustible gases such as H 2  and CO), flames, etc. 
     During the use of the battery, a large amount of gas is generated and the temperature rises rapidly inside the battery cell in a short time, which causes the pressure relief mechanism on the battery cell to be actuated, to discharge a large amount of gas into the box of the battery, causes a large amount of gas the box to gather and the temperature to rise, and may eventually cause explosion and fire of the battery. This phenomenon is called thermal runaway of the battery. 
     When thermal runaway occurs in the battery, the pressure relief mechanism on the box of the battery is actuated to relieve the pressure or temperature in the battery. However, in the prior art, the pressure relief mechanism on the box is directly exposed to the air, which causes the high-temperature gas generated when thermal runaway occurs in the battery to come in contact with oxygen in the air after being discharged by the pressure relief mechanism, which is easy to produce open flames, resulting in explosion and fire. 
     In view of this, the present application provides a fire-fighting apparatus  500  which can be configured for a battery  40 . With the fire-fighting apparatus  500 , the risk of open flames when thermal runaway occurs in the battery  40  can be reduced, and the spread of the thermal runaway of the battery  40  can be suppressed, thereby achieving the purpose of fire prevention and safety protection. 
     An embodiment of the present application provides a power consumption apparatus using a battery  40  as a power source, and the power consumption apparatus may be, but is not limited to, a vehicle, a ship or an aircraft, or the like. 
     It can be understood that the battery described in the embodiment of the present application is applicable to various apparatuses using apparatus batteries, such as mobile phones, notebook computers, battery carts, electric vehicles, ships, spacecrafts, electric toys and electric tools, etc., for example, the spacecrafts include rockets, space shuttles and spaceships, etc.; the electric toys include fixed or mobile electric toys, such as gauge consoles, electric vehicle toys, electric ship toys and electric airplane toys, etc.; the electric tools include metal cutting power tools, grinding power tools, assembly power tools and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, concrete vibrators, and electric planers. 
     The battery  40  described in an embodiment of the present application is not only applicable to the power consumption apparatus described above, but also applicable to all apparatuses that use batteries. 
     As shown in  FIG. 1 ,  FIG. 1  is a schematic structural diagram of a vehicle  10  according to an embodiment of the present application. The vehicle  10  may be a fuel-powered vehicle, a gas-powered vehicle or a new energy vehicle. The new energy vehicle may be a battery electric vehicle, a hybrid vehicle or an extended-range vehicle, or the like. A motor  20 , a controller  30  and a battery  40  may be provided inside the vehicle  10 , and the controller  30  is configured to control the battery  40  to supply power to the motor  20 , for example, the battery  40  is provided at the bottom or head of the vehicle  10 . The battery  40  may be configured to supply power to the vehicle  10 . For example, the battery  40  may be configured as an operation power source of the vehicle  10  and is configured to a circuit system of the vehicle  10 , for example, for a working power demand of the vehicle  10  during startup, navigation and running. 
     In another embodiment of the present application, the battery  40  may be configured not only as an operation power source of the vehicle  10 , but also as a driving power source of the vehicle  10 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle  10 . 
     In some embodiments, the vehicle  10  is powered by a battery  40  as shown in  FIG. 2 . The battery  40  may include a box assembly  400  and a battery cell  600 , the battery assembly  400  includes a box  410 , and the battery cell  600  is provided in the box  410 . 
     As shown in  FIG. 2-4 , the box assembly  400  provided by an embodiment of the present application may include the foregoing box  410 , a fire-fighting apparatus  500  and a pressure relief mechanism  700 . The fire-fighting apparatus  500  is provided outside the box  410 , and the fire-fighting apparatus  500  includes a pipe  510 , and an air inlet end  511  of the pipe  510  is connected to the box  410 , for example, the air inlet end  511  is connected to the box  410  through the pressure relief mechanism  700 . 
     In an embodiment of the present application, the pressure relief mechanism  700  is configured to be actuated when an air pressure or temperature in the box  410  reaches a preset value (for example, when an air pressure or temperature reaches a second threshold), so that a combustible gas in the box  410  can enter the fire-fighting apparatus  500  through the air inlet end  511 . In this way, when thermal runaway occurs in the battery  40 , the combustible gas generated by the thermal runaway of the battery cell  600  in the box  410  can be discharged into the fire-fighting apparatus  500  via the pressure relief mechanism  700 , so that the fire-fighting apparatus  500  performs fire-fighting processing on the foregoing combustible gas, thereby reducing the possibility of fire, and simultaneously reducing the air pressure inside the box  410  in time to prevent explosion. 
     In an embodiment of the present application, the pressure relief mechanism  700  may be provided on the box  410 , or provided on the fire-fighting apparatus  500 , for example, provided on the pipe  510  of the fire-fighting apparatus  500 . 
     As shown in  FIG. 2-4 , in an embodiment of the present application, the pressure relief mechanism  700  is provided on the box  410 , and the air inlet end  511  of the pipe  510  is provided on the pressure relief mechanism  700  while covering it, so that all combustible gases coming out through the pressure relief mechanism  700  can enter the pipe  510 . In other embodiments of the present application, the pressure relief mechanism  700  may be provided at the air inlet end  511 . 
     In an embodiment of the present application, as shown in  FIG. 2-4 , the box  410  may include a lower box  411  and an upper cover body  412 , and the upper cover body  412  is hermetically covered on the lower box  411 . The fire-fighting apparatus  500  may be connected to the lower box  411 . In other embodiments of the present application, the fire-fighting apparatus  500  may be connected to the upper cover body  412  of the box  410 . 
     As shown in  FIG. 5-7 , a fire-fighting apparatus  500  provided by an embodiment of the present application may include a pipe  510 , a gas release mechanism  520 , and a Hocking structure  530 . The pipe  510  has an air inlet end  511  and an air outlet end  512 . The air inlet end  511  is configured to be connected to a box  410  of the battery  40 , so that a combustible gas generated in the battery  40  during a thermal runaway event is capable of entering the pipe  510  from the box  410  via the air inlet end  511  and being discharged from the pipe  510  via the air outlet end  512 . The gas release mechanism  520  is configured to be connected to the pipe  510 , and the gas release mechanism  520  is configured to release a fire-fighting gas into the pipe  510  when thermal _runaway occurs in the battery  40 . A blocking structure  530  is provided in the pipe  510 , and is configured to block the fire-fighting gas and combustible gas and change a flow direction, so that the fire-fighting gas and combustible gas are capable of being mixed before being discharged from the pipe  510 . 
     With the foregoing technical solution, when thermal runaway occurs in the battery  40 , the combustible gas inside the box  410  enters the pipe  510  via the air inlet end  511  of the pipe  510 , so that an air pressure inside the box  410  of the battery  40  is reduced, and the possibility of explosion caused by excessive air pressure inside the box  410  is reduced. In addition, a fire-fighting gas is produced, which quickly fills the pipe  510 , and drives the combustible gas to be discharged from the air outlet end  512  of the pipe  510  after being mixed with the combustible gas. Therefore, it is possible to provide a barrier between the external air and the combustible gas discharged from the box  4101 . 
     Furthermore, a blocking structure  530  allows the combustible gas and the fire-fighting gas to mix in the pipe  510 , to reduce the concentration of the combustible gas in the pipe  510 , so that the mixed gas discharged from the air outlet end  512  of the pipe  510  is not easy to catch fire or explode when it comes into contact with air. In addition, the fire-fighting gas is also beneficial for lowering a temperature of the combustible gas, thereby further preventing the occurrence of open flames. 
     To sum up, the fire-fighting apparatus  500  provided in the foregoing embodiment of the present application could reduce the risk of open flanges when thermal runaway occurs in the battery, while suppressing the spread of thermal runaway in the battery  40 , to achieve the purpose of fire prevention and safety protection. 
     The air inlet end  511  of the pipe  510  may be directly connected to the box  410  of the battery  40 , or indirectly connected thereto through an intermediate member, which is not limited in the present application. 
     In the embodiment of the present application, the fire-fighting gas may be any suitable gas as long as it can have a fire prevention effect after being mixed with the combustible gas. 
     In some embodiments of the present application, the fire-fighting gas may include a non-combustible gas such as an inert gas, carbon dioxide gas, heptafluoroproparre gas, sulfur hexafluoride, or the like. 
     In order to ensure the full mixing of the fire-fighting gas and the combustible gas, the blocking structure  530  may be configured to make a flow path of at least part of a gas in the pipe  510  a meandering shape, that is, through the blocking structure  530 , the mixed gas of the fire-fighting gas and the combustible gas at least partially travels along a curved path toward the air outlet end  512  of the pipe  510  in the pipe  510 . The advantages of the gas traveling in the pipe  510  in a meandering manner are as follows: on one hand, a mixing path of the fire-fighting gas and the combustible gas can be extended, and a mixing time of the fire-fighting gas and the combustible gas can be increased, thereby improving the mixing effect of the two; on another hand, traveling in a meandering manner intensifies the colliding and mixing of the fire-fighting gas and the combustible gas, thereby improving the mixing effect of the two and reducing the situation of the occurrence of fire due to the excessively high local concentration of the combustible gas even discharged from the pipe  510 . 
     Here, the flow path of the gas in “the meandering shape” may mean that the flow path of the gas in he pipe  510  is any suitable curved shape such as an shape, a spiral shape, a sine/cosine wave, or the like. 
     In order to ensure that the gas travels in the pipe  510  in a meandering manner, in some embodiments of the present application, a projection of the blocking structure  530  in an extension direction of the pipe covers a projection of a cavity (that is, an inner passage) of the pipe  510  in the extension direction of the pipe  510 . For example, in the embodiment shown in  FIG. 6 , a projection of two baffle plates  531  of the blocking structure  530  that are disposed at interval in an extension direction of the pipe  510  covers a projection of a cavity of the pipe  510  in the extension direction of the pipe  510 , so that the combustible gas discharged from the box  410  and the fire-fighting gas both in the pipe  510  flow through the blocking structure  530  and travel in a meandering manner rather than in a straight line. 
     In the embodiment of the present application, the blocking structure  530  may have any appropriate structure as long as it can make a flow path of the gas a meandering shape when the gas flows through the blocking structure  530 . 
     As shown in  FIG. 714 , in an embodiment of the present application, a blocking structure  530  may include a plurality of baffle plates  531 , and the plurality of baffle plates  531  are arranged at interval in an extension direction of a pipe  510 . The baffle plate  531  is provided with an opening  800  for a gas to pass through, or the baffle plate  531  encloses with an inner wall of the pipe  510  to form an opening  800  for a gas to pass through. The projections of two adjacent openings  800  in the extension direction of the pipe  510  are disposed to be misaligned, so that when the gas flows through the plurality of baffle plates  531 , a flow path of the gas is in a meandering path. The baffle plate  531  can not only mix the gases, but also prevent a high-temperature particle entering the pipe  510  from the box  410  from flowing out of the pipe  510 , thereby avoiding risks that may be caused by the outflow of the high-temperature particle, such as causing a fire. 
     As described above, in order to allow the gas to pass through the blocking structure  530 , the baffle plate  531  may be provided with an opening  800 , or the baffle plate  531  may enclose with an inner wall of the pipe  510  to form. an opening  800 , or the baffle plate  531  may be provided with an opening  800 , and meanwhile the baffle plate  531  and the inner wall of the pipe  510  may also define the opening  800 . 
     As shown in  FIG. 8  and  FIG. 9 , in some embodiments of the present application, each baffle plate  531  encloses with the inner wall of the pipe  510  are enclosed to form an opening  800 , and corresponding two adjacent openings  800  formed by enclosing the inner wall of the pipe  510  with baffle plate  531  are disposed to be misaligned. As shown in  FIG. 8 , a shape of the opening  800  is a quarter circle. As shown in  FIG. 9 , a shape of the opening  800  is a semicircle. 
     As shown in  FIG. 10 , in an embodiment of the present application, an opening  800  is formed on each baffle plate  531 , and the two adjacent openings  800  formed by the baffle plates  531  and the inner wall of the pipe  510  are disposed to be misaligned. The shape of the opening  800  may be a circle. 
     It should be noted that the specific shape of the opening  800  is not limited in the present application, but may be determined according to the shape of the projection (that is, the cross section) of the pipe  510  in the extension direction of the pipe  510  and the shape of the baffle plate  531 . In addition to the shapes shown in  FIG. 8  to  FIG. 10 , it may be a square, a polygon, or the like. 
     As shown in  FIG. 11 , in an embodiment of the present application, the baffle plate  531  is a circular baffle plate with a quarter circular notch. A diameter of the circular baffle plate may be equal to an inner diameter of the pipe  510 , so that when an outer edge of the circular baffle plate is connected to an inner wall of the pipe  510 , the circular baffle plate and the inner wall of the pipe  510  may be enclosed to form an opening  800  with a quarter circle shape. 
     A plurality of the above-mentioned circular baffle plates with notches may be divided into two groups, and the two groups of circular baffle plates are arranged at interval in the extension direction of the pipe  510 . Each group of circular baffle plates includes four circular baffle plates, the four circular baffle plates are arranged at interval in the extension direction of the pipe  510 , and projections of quarter circular notches of two adjacent circular baffle plates in the extension direction of the pipe  510  are disposed to be misaligned. In this way, when the mixed gas of the fire-fighting gas and the combustible gas flows through the foregoing four circular baffle plates with notches, a flow path of the mixed gas is in a spiral shape, which is beneficial for the full mixing of the fire-fighting gas and the combustible gas. 
     As shown in  FIG. 11 , the plurality of baffle plates  531  may be connected as a whole through a first connecting of  533  to facilitate the connection between the plurality of baffle plates  531  and the pipe  510 . For example, when the plurality of baffle plates  531  are installed, only one of the baffle plates  531  is needed to be connected to the inner wall of the pipe  510  rather than each baffle plate  531  to be connected to the inner wall of the pipe  510 . 
     It can be understood that the number of the foregoing circular baffle plates with notches is not limited in the present application, and the number thereof may be eight as shown in  FIG. 11 , or may be only one group of the foregoing circular baffle plates, that is, four circular baffle plates are provided. Alternatively, only two circular baffle plates may be provided, so that a path of the gas flowing through the two circular baffle plates is S-shaped, which is also beneficial for the mixing of the fire-fighting gas and the combustible gas. 
     As shown in  FIG. 12-14 , in some embodiments of the present application, a plurality of baffle plates  531  at least include a pair of arc-shaped plates, and concave surfaces  5311  of the pair of arc-shaped plates are disposed opposite to each other. Since the concave surfaces  5311  of the pair of arc-shaped plates are disposed opposite to each other, when a gas enters an interval of the pair of arc-shaped plates, a concave surface  5311  of one arc-shaped plate of the pair of arc-shaped plates can guide the gas toward the other arc-shaped plate, which could intensify the collision of gases between the pair of arc-shaped plates and increase the mixing time of the gases, and thus it is beneficial or a full mixing of the fire-fighting gas and the combustible gas. 
     It should be noted that the embodiment of the present application does not limit the specific shape of the arc-shaped plate. Optionally, the arc-shaped plate may be configured as a C-shaped plate as shown in  FIG. 12 , or as a spherical plate as shown in  FIG. 13  and  FIG. 14 . The C-shaped plate and the spherical plate are simple in structure. In other embodiments of the present application, the arc-shaped plate may be an S-shaped plate, or the like. 
     As shown in  FIG. 15  and  FIG. 16 , in an embodiment of the present application, a blocking structure  530  includes a spiral blade  532 . A centerline of the spiral blade  532  may coincide with or be parallel to a central axis of the pipe  510 , so that the spiral blade  532  can make a flow path of the mixed gas a spiral shape, which is beneficial for the full mixing of the fire-fighting gas and the combustible gas. 
     In order to further improve the mixing effect of the blocking structure  530  on the fire-fighting gas and the combustible gas, as shown in  FIG. 15  and  FIG. 16 , there may be a plurality of spiral blades  532  (for example, two spiral blades), and the plurality of spiral blades  532  are arranged in an extension direction of the pipe  510 , and directions of rotation of two adjacent spiral blades  532  are opposite. The spiral blades  532  with two different rotary directions may change a direction of rotation of the gas, which could further enhance the effect of mixing the gases. 
     As shown in  FIG. 16 , a plurality of spiral blades  532  may be connected as a whole through a second connecting rod  534  to facilitate the connection between the plurality of spiral blades  532  and the pipe  510 . For example, when the plurality of spiral blades  532  are installed, may be enough to connect only one of the spiral blades  532 . may be connected to the inner wall of the pipe  510  rather than connect each spiral blade  532  to the inner wall of the pipe  510 . 
       FIG. 16  shows an embodiment in which there are two spiral blades  532 . In other embodiments of the present application, the number of the spiral blades  532  may be multiple such as, three, four, five, or the like, which may be determined according to factors such as the size of the pipe  510  in the extension direction, and the present application does not limit thereto. 
     In addition, as shown in  FIG. 17 , in an embodiment of the present application, a baffle plate  531  and a spiral blade  532  may be provided in the pipe  510  at the same time. 
     In addition, as shown in  FIG. 18 , in an embodiment of the present application, a wall of the pipe  510  is recessed inwardly to form a convex part  535  in a cavity of the pipe  510  and the convex part  535  can play a role in blocking the air flow, changing the direction of the air flow, which is beneficial for the mixing of the fire-fighting gas and the combustible gas. That is, in this embodiment, the blocking structure  530  includes the convex part  535 . 
     As shown in  FIG. 18 , there may be a plurality of convex parts  535 , and the plurality of convex parts  535  are arranged at interval in an extension direction of the pipe  510 , so as to further enhance the effect of blocking the gas and improve the effect of mixing the combustible gas and the fire-fighting gas. 
     In addition, as shown in  FIG. 18 , the plurality of convex parts  535  may include at least one pair of arc-shaped convex parts, and arc-shaped concave surfaces  5351  of the arc-shaped convex parts are disposed opposite to each other. When a gas enters an interval of the pair of arc-shaped convex parts, an arc-shaped concave surface of one arc-shaped convex part of the pair of arc-shaped convex parts can guide the gas towards the other arc-shaped convex part, which could intensify the collision of gases between the pair of arc-shaped convex parts and increase the mixing time of the gases, and thus it is beneficial for a full mixing of the fire-fighting gas and the combustible gas. 
     In addition, it should be noted that, in addition to the foregoing ways of arranging the baffle plate  531  and the spiral blades  532  in the pipe  510  or forming the convex part  535  by recessing the wall of the pipe  510  to construct the blocking structure  530 , in other embodiments of the present application, a plurality of small protrusions may be provided on the inner wall of the pipe  510  to construct the blocking structure  530 . In other embodiments, the cavity (that is, the internal passage) of the pipe  510  may also be designed, for example, the cavity is designed to include a plurality of cavity segments in the extension direction of the pipe  510 , and at least one pressurized cavity segment is included in the plurality of cavity segments. In this way, when the fire-fighting gas and the combustible gas flow through the pressurized cavity segment, the flow rate is increased, which is beneficial for the uniform mixing of the two. Here, the pressurized cavity segment may be configured as a structure whose internal cavity is tapered along a direction from the air inlet end  511  to the air outlet end  512  of the pipe  510 . 
     As shown in  FIG. 17  to  FIG. 19 , in some embodiments of the present application, an installation position of the gas release mechanism  520 while compared with the blocking structure  530 , is closer to the air inlet end  511 , so as to facilitate the full mixing of the fire-fighting gas and the combustible gas through the blocking structure  530 , thereby ensuring the mixing effect of the blocking structure  530  on the fire-fighting gas and the combustible gas. 
     It can be understood that in other embodiments of the present application, when the number of the blocking structures  530  is multiple, or each blocking structure  530  includes a plurality of baffle plates  531 , the installation position of the gas release mechanism  520  on the pipe  510  may be located between the plurality of blocking structures  530 , or between the plurality of baffle plates  531 . 
     In an embodiment of the present application, the gas release mechanism  520  may be directly connected to the pipe  510 , for example, plugged into the pipe  510 . The gas release mechanism  520  may also be indirectly connected to the pipe  510 , for example, the gas release mechanism  520  is connected to a gas guiding pipe and the gas guiding pipe extends from the air outlet end of the pipe  510  to a position close to the air inlet end  511  of the pipe  510 , and the gas guiding pipe is configured to guide a gas released by the gas release mechanism  520  into the pipe  510 . 
     As shown in  FIG. 19 , in some embodiments of the present application, the gas release mechanism  520  is directly installed at the pipe  510 . The direct installation of the gas release mechanism  520  at the pipe  510  could shorten the time for the fire-fighting gas to enter the pipe  510 , and omit an intermediate connector between the gas release mechanism  520  and the pipe  510 , for example, omit the foregoing gas guiding pipe, and the structure could be simplified and the cost could be saved. 
     The gas release mechanism  520  may be disposed either outside or inside the pipe  510 . 
     As shown in  FIG. 19  and  FIG. 20 , in an embodiment, of the present application, a gas release mechanism  520  may be disposed outside a pipe  510 . A through hole  513  is provided on a wall of the pipe  510 , and the gas release mechanism  520  is connected to the through hole  513  to release a fire-fighting gas into the pipe  510  through the through hole  513 . The gas release mechanism  520  is disposed outside the pipe  510 , so that a size of the gas release mechanism  520  may not be limited by a size of a cavity of the pipe  510 , which is beneficial for the installation of the gas release mechanism  520  which has a larger gas production. 
     As shown in  FIG. 19  and  FIG. 20 , in an embodiment of the present application, the number of through holes  513  is multiple, and the multiple through holes  513  are arranged at interval in an extension direction of the pipe  510 . The multiple through holes  513  may ensure a rapid release of a sufficient amount of fire-fighting gas, thus ensuring the reliability of fire prevention. 
     Regarding the relationship between the through hole  513  and the gas release mechanism  520 , each through hole  513  may correspond to one gas release mechanism  520 , or multiple through holes  513  may correspond to one gas release mechanism  520 . In other words, only one gas release mechanism  520  may be provided, and the gas release mechanism  520  is connected to the pipe  510  through the multiple through holes  513 . A plurality of gas release mechanisms  520  may be provided, and each gas release mechanism  520  may correspond to one, two or any suitable number of through holes  513 . 
     The foregoing through hole  513  may be configured as a threaded through hole  513  to form a threaded connection with the gas release mechanism  520 , so as to ensure the reliability of the installation of the gas release mechanism  520  on the pipe  510  and the sealing connection of the gas release mechanism  520  and the pipe  510 . 
     Optionally, a sealant (a sealing silicone rubber) may be provided at a connection position of the gas release mechanism  520  and the pipe  510  to further ensure the sealing performance of the connection between the gas release mechanism  520  and the inner wall of the through hole  513 . 
     The embodiment of the present application does not limit a length L of the pipe. Optionally, as shown in  FIG. 19 , in an embodiment of the present application, the length L of the pipe is 50-200 cm. The advantages of setting the length L of the pipe within such a range are as follows: first, it facilitates the installation of the gas release mechanism  520 , which is beneficial for the installation of a plurality of gas release mechanisms  520 ; second, a distance for lowering temperature is increased, so that the mixed gas of the fire-fighting gas and the combustible gas has a sufficient distance for lowering temperature, and thus the possibility of catching a fire at the air outlet end of the pipe  510  is reduced; third, a distance for exchanging the oxygen is increased, so that a high-temperature region near the box  410  becomes an oxygen-deficient region, thereby reducing the risk of open flames in the high-temperature region. 
     In order to facilitate the connection between the pipe  510  and the box  410 , as shown in  FIG. 19  and  FIG. 20 , in an embodiment of the present application, the air inlet end  511  of the pipe  510  is provided with a flange  514 . 
     As shown in  FIG. 21 , a fire-fighting apparatus  500  also includes a gas collection device  540 , and the gas collection device  540  is hermetically connected to the air outlet end  512  of the pipe  510 , and is configured to collect a gas discharged from the air outlet end, so as to prevent the mixed gas from being directly discharged to the external environment, and polluting the environment. 
     In an embodiment of the present application, the gas release mechanism  520  may have any suitable structure and shape. As shown in  FIG. 22-25 , the gas release mechanism  520  may include a fire-fighting medium  521  (a fire-fighting agent), a housing  522 , and a closure member  523 . The fire-fighting medium  521  may be a fire-fighting gas or a fire-fighting solid or a fire-fighting liquid capable of generating the fire-fighting gas. The housing  522  is configured to accommodate the fire-fighting medium  521 , and the housing  522  is connected to the through hole  513 , and the housing  522  is provided with an air outlet hole  5221 . The closure member  523  is configured to enclose the air outlet hole  5221 , and the closure member  523  is configured to release closure of the air outlet hole  5221  when thermal runaway occurs in the battery  40 , so that the fire-fighting gas enters the pipe  510  through the air outlet hole  5221 . 
     In this embodiment, when the battery  40  works normally, the closure member  523  closes the air outlet hole  5221 . When thermal runaway occurs in the battery  40 , the closure member  523  releases the closure of the air outlet hole  5221 , that is, the air outlet hole  5221  opens, so that the fire-fighting gas in the housing  522  can enter the pipe  510  through the air outlet hole  5221  to realize mixing with the combustible gas. 
     Here, in addition to the inert gas, carbon dioxide gas, heptafluoropropane gas, sulfur hexafluoride, or the like, the fire-fighting gas may he any other appropriate gas that is helpful to prevent fires, which is not listed here. 
     The closure, member  523  may be configured to open when a pressure (such as the air pressure in the housing  522 ) reaches a certain value, or may be configured to open when a temperature reaches a certain value if the closure member  523  is a membrane or a pressure valve, for example, the closure member  523  is configured as a meltable membrane, to be capable of melting when the temperature reaches a certain value, so as to open the air outlet hole  5221 . 
     As shown in  FIG. 22  and  FIG. 23 , the fire-fighting medium  521  is a fire-fighting solid or a fire-fighting liquid, the gas release mechanism  520  further includes a trigger  524 , and the trigger  524  is configured to trigger the fire-fighting solid or fire-fighting liquid to generate a fire-fighting gas when thermal runaway occurs in the battery. The closure member  523  is configured to be able to open the air outlet hole  5221  when the air pressure in the housing  522  reaches a first threshold, so as to release the fire-fighting gas. 
     In this embodiment, when thermal runaway occurs in the battery  40 , the trigger  524  triggers the fire-fighting medium  521  to generate a large amount of fire-fighting gas, and the fire-fighting gas gathers in the housing  522  so that the air pressure in the housing  522  increases. When the air pressure reaches the first threshold, the air outlet hole  5221  opens through the closure member  523 , and the fire-fighting gas in the housing  522  enters the pipe  510  through the through hole  513 . 
     The trigger  52 . 4  may be an electrically controlled thermal initiator, which generates heat when thermal runaway occurs in the battery, so as to trigger the fire-fighting solid or the fire-fighting liquid to generate the fire-fighting gas. 
     In addition, the foregoing “first threshold” may be any appropriate value, and the specific parameter may be determined according to the actual situation. 
     In an embodiment of the present application, a controller may be used to send a trigger signal to the trigger  524 . The controller configured to send the trigger signal to the trigger  524  may be a controller of the battery  40  or a built-in controller of the fire-fighting apparatus  500 . The controller may detect the thermal runaway of the battery  40  through, for example, a temperature sensor or a smoke sensor, or the like. When the thermal runaway occurs in the battery  40 , the temperature sensor or the smoke sensor may send the detected result to the controller, and then the controller controls the trigger  524  to work according to the detection structure of the temperature sensor or the smoke sensor. 
     As shown in  FIG. 22 , the gas release rnechanism  520  also includes a lead  525 , one end of the lead  525  is electrically connected to the trigger  524 , and another end thereof may pass through the housing  522  and be electrically connected to an external controller. The controller sends, to the trigger  524  through the lead  525 , a trigger signal used for triggering the fire-fighting medium  521  to generate the gas. In other embodiments, the controller may communicate wirelessly with the trigger  524 . 
     As shown in  FIG. 2.4  and  FIG. 25 , in another embodiment of the present application, a fire-fighting medium  521  is a fire-fighting liquid or a fire-fighting gas capable of generating a fire-fighting gas, and the fire-fighting liquid or the fire-fighting gas is encapsulated in a housing  522 . When a closure member  523  closes the air outlet hole  5221 , a pressure in the housing  522  is greater than a pressure in the pipe  510 , that is, the fire-fighting liquid or the fire-fighting gas is pressurized and encapsulated in the housing  522 , and the closure member  523  is a valve, such as an electric control valve. 
     In this embodiment, when the battery  40  is in normal conditions, a certain pressure is maintained in the housing  522 , and the closure member  523  closes the air outlet hole  5221 . If the fire-fighting medium  521  is the fire-fighting liquid, when thermal runaway occurs in the battery  40 , the air outlet hole  5221  opens through the closure member  523 , so that the inner portion of the housing  522  communicates with the inner portion of the pipe  510 , and the pressure in the housing  522  decreases, so that the fire-fighting liquid is vaporized and enters the pipe  510  through the air outlet hole  5221 . 
     In this embodiment, when the fire-fighting medium  521  is the fire-fighting gas, since the fire-fighting gas is pressurized and encapsulated in the housing  522 , the fire-fighting gas may be sprayed into the pipe  510  when the air outlet hole  5221  opens through the closure member  523 , thereby ensuring the reliability of releasing the gas into the pipe  510  by the gas release mechanism  520 . 
     As shown in  FIG. 24  and  FIG. 25 , the housing  522  is also provided with a sealing valve  526  configured to input the fire-fighting liquid or the fire-fighting gas. 
     In the embodiment of the present application, the fire-fighting medium may be one or more of the fire-fighting solid, the fire-fighting liquid and the fire-fighting gas, which is not limited in the present application. 
     The fire-fighting solid, such as a solid aerosol, is adjustable in both size and shape, and also has a large gas production per unit volume, which can maximize the space utilization. The fire-fighting solid is triggered to generate the gas when the thermal runway occurs, forming an aerosol form. 
     Optionally, the fire-fighting medium  521  may be selected from a substance that can generate a free radical scavenger or contain a free radical scavenges, and the free radical scavenger, also known as a free radical capture agent is a substance that can react with an active free radical to form a stable free radical or a stable molecule. For example, 2,2-diphenyl-1-trinitrophenylhydrazine (DPPIT), p-benzoquinone, tetramethylbenzoquinone, rosomethane, and phenyl-N-tert-butyl nitrone, etc. can react with the free radical to form a stable free radical. 
     In this embodiment, the fire-fighting medium  521  is solid potassium nitrate, which thermally decomposes to form a free radical scavenger. The free radical scavenger is easier to combine with oxygen (including oxygen in the gas discharged from the pressure relief mechanism  700 , oxygen in the pipe  510 , and oxygen in the external environment) or a substance discharged from the pressure relief mechanism  700  that is easy to combine with oxygen to generate a high-temperature combustible substance, and the substance combined with the free radical scavenger is a combustible free radical. The free radical scavenger can consume a combustible free radical generated after the thermal runaway of the battery  40 , which reduces the possibility of combining and combusting of the combustible free radical and oxygen, and reduces the possibility of enerating open flames from tackling the root cause. The free radical scavenger combining with the combustible free radical can generate inert gas such as nitrogen, the inert gas is difficult to chemically react with oxygen or other substances, and occupies the internal space of the pipe  510 , so as to reduce the oxygen content in the pipe  510 , dilute the gas in the pipe  510  and reduce the concentration of combustible substances and oxygen in the pipe  510 . The inert gas occupying the inner space of the pipe  510  also acts as a barrier between the external air and the gas discharged from the pressure relief mechanism  700 , thereby reducing or avoiding the contact between the external air and the gas discharged from the pressure relief mechanism  700 . In addition, decomposition of the reagent absorbs heat, which could lower the temperature in the pipe  510  and further prevent the generation of open flames. Different reagents produce different free radical scavengers, and the combustible free radicals that can be combined with are also different, so that different inert gases can be produced. 
     The fire-fighting liquid may be liquid sulfur hexafluoride or hexafluoropropane, and the gasification thereof can achieve the effect of lowering the temperature. Since sulfur hexafluoride or hexafluoropropane has strong electrical insulation characteristics, it, can dilute the combustible gas while protecting the high voltage circuit of the battery  40 . 
     In an embodiment of the present application, the housing  522  of the gas release mechanism  520  may be a steel housing such as a stainless steel housing) to ensure the strength of the housing  522 . 
     According to another aspect of the present application, a method for producing a battery is provided, as shown in  FIG. 26 , the method includes the following steps. 
     S 1 , providing a battery cell  600 ; S 2 , providing a box  410 ; 
     S 3 : providing a fire-fighting apparatus  500 , the fire-fight apparatus  500  includes a pipe  510  and a gas release mechanism  520 , the pipe  510  has an air inlet end  511  and an air outlet end, and the air inlet end  511  is configured to be connected to the box  410 , so that a combustible gas generated in the battery during a thermal runaway is capable of entering the pipe  510  from the box  410  via the air inlet end  511  and being discharged from the pipe  510  via the air outlet end  512 . The gas release mechanism  520  is connected to the pipe  510 , and the gas release mechanism  520  is configured to release a fire-fighting gas into the pipe  510  when thermal runaway occurs in the battery. A blocking structure  530  is provided in the pipe  510 , and the blocking structure  530  is configured to block the fire-fighting gas and the combustible gas and change a flow direction, so that the combustible gas and the fire-fighting gas are capable of being mixed before being discharged from the pipe  510 ; 
     S 4 : disposing the battery cell  600  in the box  410 ; and S 5 : disposing the fire-fighting apparatus  500  outside the box  410 , and connecting the air inlet end  511  to the box  410 . 
     It should be noted that the sequence of the foregoing steps can be adjusted as required. For example, may first connect the air inlet end  511  of the pipe  510  of the fire-fighting apparatus  500  with the box  410  to form a box assembly  400 , then place the battery cell  600  in the box  410  of the box assembly  400 . 
     The pipe  510 , the gas release mechanism  520 , and the blocking structure  530  may be the foregoing pipe  510 , the foregoing gas release mechanism  520 , and the foregoing blocking structure  530 . 
     The foregoing descriptions are merely preferred embodiments of the present application, and are not intended to limit the present application. For a person of skilled in the art, the present application may have various modifications and variations. Any modification, equivalent substitution, improvement etc., made within the spirit and principle of the present application shall fall within the protection scope of the present application.