Battery pack and energy storage system

Abstract

A battery pack. The battery pack comprises a casing, wherein the casing is configured to accommodate a battery cell, and an explosion-proof valve is provided on a wall of the casing. The explosion-proof valve comprises a valve body and a valve cover, wherein the valve body comprises an inner cavity, the valve cover is configured to seal the inner cavity, the valve body is provided with an air vent, and the air vent is configured to communicate the inner cavity with the interior of the casing. A cover is disposed in the casing, the cover comprises a first side plate, the projection of the first side plate on the wall covers the air vent, and the first side plate is provided with a plurality of first through holes. When thermal runaway occurs in the battery cell, a solid component released by the battery cell flows to the explosion-proof valve along with a high-temperature gas, and the first side plate of the cover can block the solid component or an electrolyte released by the battery cell when thermal runaway occurs, so as to prevent the solid component or the electrolyte from blocking the explosion-proof valve and thus damaging the explosion-proof valve. Meanwhile, the high-temperature gas generated by the battery cell when thermal runaway occurs can be released from the plurality of first through holes to the explosion-proof valve, and then released to the outside of the battery pack by means of the explosion-proof valve, thereby ensuring the pressure relief capability of the battery pack.

Description

Battery pack and energy storage system

[0001] The present application claims priority to the Chinese patent application No. 202421530073.7, filed on June 28, 2024, and entitled "A battery pack and energy storage system", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of energy storage, in particular to a battery pack and energy storage system. BACKGROUND

[0003] Battery packs are widely used in energy storage systems. In the energy storage system, the battery pack is used to store electrical energy through charging and discharge and supply the stored electrical energy to users. The battery cell is the basic unit for realizing the mutual conversion of chemical energy and electrical energy in the battery pack. With the further improvement of the energy density of the battery cell, the safety problem of the battery cell is increasingly prominent. The battery cell with high energy density is prone to thermal runaway under the working conditions of collision, overheating, extrusion or needle puncture, and a large amount of heat and flammable gas will be released in an instant when the battery cell is in thermal runaway. After the battery cell is in thermal runaway, a large number of battery cells are prone to cause chain-like thermal runaway, which may cause the battery pack to catch fire or even explode.

[0004] During the thermal runaway process of the battery pack, high-temperature gas is generated in the battery cell in the battery pack, the explosion-proof valve of the battery pack is opened, and the high-temperature gas is quickly released from the explosion-proof valve of the battery pack to the outside of the battery pack, thereby reducing the risk of explosion of the battery pack. During the thermal runaway process of the battery pack, part of the auxiliary materials (such as plastic structural parts, aluminum bars, plastic insulation parts, etc. of the battery pack, and structural parts, jacking pieces, etc. inside the battery cell) in the battery pack will melt at high temperature, separate from the original fixed position and be blown to the explosion-proof valve port with high-speed smoke gas during thermal runaway, which may block the explosion-proof valve port or cause the explosion-proof valve to deform and fail, so that the high-temperature gas in the battery pack cannot continue to be discharged, thereby causing the entire battery pack to catch fire or explode. SUMMARY

[0005] The present application provides a battery pack, a cover is arranged on the wall of the battery pack where the explosion-proof valve is arranged, and the cover is located inside the battery pack. On the one hand, a plurality of first through holes are arranged on the cover for flowing the high-temperature gas released during thermal runaway of the battery cell. On the other hand, the cover can block the solid components generated during thermal runaway of the battery pack and the released electrolyte, thereby preventing foreign matter from blocking the explosion-proof valve.

[0006] In a first aspect, the application provides a battery pack, the battery pack comprising a shell, the shell being configured to accommodate a battery cell, the shell comprising four side walls and a top wall, the four side walls being arranged opposite to each other in pairs, and the top wall being connected to the four side walls, the top wall and the four side walls forming an accommodation cavity configured to accommodate the battery cell. The wall of the shell is provided with an explosion-proof valve, the wall being any one of the four side walls and the top wall. The explosion-proof valve comprises a valve body and a valve cover, the valve body comprising an inner cavity, the valve cover being configured to seal the inner cavity, and the valve body being provided with a gas vent, the gas vent being configured to communicate the inner cavity with the inside of the shell. When the internal pressure of the battery pack increases, the high-temperature gas released by the battery pack can be discharged to the outside of the battery pack through the gas vent after the explosion-proof valve is opened. The inside of the shell is provided with a cover shell, the cover shell comprising a first side plate, a projection of the first side plate on the wall covering the gas vent, and a plurality of first through holes being provided on the first side plate. When the battery cell is in thermal runaway, the solid components released by the battery cell in thermal runaway can flow to the explosion-proof valve along with the high-temperature gas, the cover shell can block the solid components or electrolyte released by the battery cell in thermal runaway, prevent the solid components or electrolyte from blocking the gas vent of the explosion-proof valve, inhibit the release of gas in the battery pack, and prevent the battery pack from burning and exploding. At the same time, the high-temperature gas generated by the battery cell in thermal runaway can be released to the explosion-proof valve through the plurality of first through holes, and then released to the outside of the battery pack through the explosion-proof valve, thereby ensuring the pressure relief capability of the battery pack.

[0007] In a possible implementation, the gas vent is a plurality of gas vents, and the plurality of first through holes and the plurality of gas vents are not arranged in overlapping manner. The blocking effect of the first side plate on the solid components released by the battery cell can be enhanced, and the solid components can be prevented from flying to the explosion-proof valve through the plurality of first through holes, thereby blocking the gas vent.

[0008] In a possible implementation, the explosion-proof valve is arranged opposite to and spaced apart from the first side plate. By arranging the explosion-proof valve opposite to the first side plate, the explosion-proof valve can be completely prevented from being exposed to the periphery of the battery cell in thermal runaway, the blocking effect of the first side plate on the solid components released by the battery cell in thermal runaway can be enhanced, and the solid components released by the battery cell in thermal runaway can be prevented from flying to the explosion-proof valve.

[0009] In a possible implementation manner, the valve cover is located outside the wall and is spaced apart from the wall, the first side plate is provided with a second through hole, the wall is provided with a valve hole for mounting an explosion-proof valve, the second through hole is located opposite the valve hole, and the valve body passes through the valve hole and the second through hole in sequence. The valve body is provided with an elastic member, and the elastic member is used to drive the valve cover to move away from the wall when the air pressure in the battery pack increases. When the battery pack is in thermal runaway, the voltage inside the battery pack increases sharply, and the elastic member drives the valve cover to pop up, so that the gas in the battery pack is released to the outside through the gas vent of the explosion-proof valve. The distance between the first side plate and the wall can be shortened while the blocking effect of the first side plate is ensured, the structural compactness of the components inside the battery pack is improved, and the energy density of the battery pack is improved.

[0010] In a possible implementation manner, the plurality of battery cells form a battery module, and the minimum distance between the first side plate and the battery module is greater than 0. The first side plate and the battery module are spaced apart on the side close to the wall, and when the battery pack is in thermal runaway, the high-temperature gas released can flow to the first through hole from the gap, thereby improving the pressure relief capability of the battery pack.

[0011] In a possible implementation manner, the plurality of battery cells form a battery module, and the minimum distance between the valve body and the battery module is greater than 0. The valve body and the battery module are spaced apart on the side close to the wall, and when the battery pack is in thermal runaway, the high-temperature gas released can flow to the first through hole from the gap, thereby improving the pressure relief capability of the battery pack.

[0012] In a possible implementation manner, the cover shell includes four second side plates, the four second side plates are located opposite each other, the four second side plates are perpendicular to and connected with the first side plate, and at least one third through hole is formed in at least one of the four second side plates. If the solid components released by the battery cells in thermal runaway block the first through hole of the first side plate of the cover shell, the high-temperature gas released by the battery cells in thermal runaway can also be released to the outside of the battery pack through the third through hole and the explosion-proof valve, thereby improving the pressure relief effect of the battery pack.

[0013] In a possible implementation manner, one of the four second side plates is located opposite the bottom wall of the battery pack, and the one second side plate is provided with at least one third through hole. After the solid components released by the battery cells in thermal runaway enter the cover shell through the first through hole, the solid components can fall to the bottom wall of the battery pack through the third through hole of the one second side plate, thereby preventing the solid components from blocking the explosion-proof valve.

[0014] In a possible implementation manner, the sum of the areas of the plurality of first through holes is greater than the pressure relief area of the explosion-proof valve. When the battery cell is in thermal runaway, the high-temperature gas generated can be timely released from the plurality of first through holes and the explosion-proof valve to the outside of the battery pack, thereby ensuring the pressure relief effect of the battery pack.

[0015] In a possible implementation manner, the diameter of each of the plurality of first through holes is greater than or equal to 2 mm. The diameter of the first through hole is prevented from being too small, so that the high-temperature gas generated due to thermal runaway of the battery cell cannot be quickly discharged in the battery pack, thereby ensuring the pressure relief effect of the battery pack.

[0016] In a possible implementation manner, the diameter of each of the plurality of first through holes is less than or equal to 10 mm. The diameter of the first through hole is prevented from being too large, so that the solid components released by the battery cell are prevented from being released into the shell through the first through hole, thereby blocking the explosion-proof valve.

[0017] In a possible implementation manner, the sum of the areas of the at least one third through hole is greater than the pressure relief area of the explosion-proof valve. The high-temperature gas in the battery pack is timely discharged to the outside of the battery pack, thereby ensuring the pressure relief effect of the battery pack.

[0018] In a possible implementation manner, the diameter of each of the at least one third through hole is greater than or equal to 2 mm. The pressure relief capability of the battery pack is further enhanced.

[0019] In a possible implementation manner, the shell includes two fixing arms parallel to the first side plate, the two fixing arms are respectively connected with two oppositely arranged second side plates of the four second side plates, and the two fixing arms are fixedly connected with the wall, thereby enhancing the stability of the connection between the shell and the side wall of the battery pack.

[0020] In a possible implementation manner, the shell includes two fixing arms parallel to the first side plate, the two fixing arms are respectively connected with two oppositely arranged second side plates of the four second side plates, and the two fixing arms are fixedly connected with the wall, thereby enhancing the stability of the connection between the shell and the side wall of the battery pack.

[0021] In a possible implementation manner, the shell includes two fixing arms parallel to the first side plate, the two fixing arms are respectively connected with two oppositely arranged second side plates of the four second side plates, and the two fixing arms are fixedly connected with the wall, thereby enhancing the stability of the connection between the shell and the side wall of the battery pack. BRIEF DESCRIPTION OF DRAWINGS

[0022] Fig. 1 is a structural schematic diagram of a battery pack according to an embodiment of the present application;

[0023] Fig. 2 is a side structural sectional view of a battery pack according to an embodiment of the present application;

[0024] Fig. 3 is an enlarged schematic diagram of the structure at A in Fig. 2;

[0025] Fig. 4 is a front view of a wall of a battery pack according to an embodiment of the present application;

[0026] Fig. 5 is a structural schematic diagram of a cover of a battery pack according to an embodiment of the present application installed in a housing;

[0027] Fig. 6 is a structural schematic diagram of a cover of a battery pack according to an embodiment of the present application.

[0028] Fig. 1 is a structural schematic diagram of a battery pack according to an embodiment of the present application; DETAILED DESCRIPTION

[0029] In order to make the objects, technical solutions and advantages of the present application clearer, the following will further describe the present application with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms, and should not be understood as being limited to the embodiments set forth herein. The same reference signs in the drawings represent the same or similar structures, and thus repeated description thereof will be omitted. The expressions of position and direction described in the embodiments of the present application are described with reference to the drawings, but can be changed as needed, and the changes made are included in the scope of protection of the present application. The drawings of the embodiments of the present application are only used to illustrate the relative positional relationship and do not represent the true proportions.

[0030] In the embodiments of the present application, the terms "first", "second", and the like are only used for descriptive purposes, and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features.

[0031] It should be noted that specific details are set forth in the following description in order to facilitate understanding of the present application. However, the present application can be implemented in various other ways than those described herein, and those skilled in the art can make similar generalizations without departing from the scope of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0032] For the convenience of understanding, the terms involved in the embodiments of the present application are first explained.

[0033] Plural: refers to two or more than two.

[0034] "Connection" should be understood broadly, for example, "connection" can be detachable connection, or non-detachable connection; can be direct connection, or indirect connection through intermediate medium. "Fixed" should also be understood broadly, for example, "fixed" can be direct fixation, or indirect fixation through intermediate medium.

[0035] The embodiments of the present application are described below in combination with the drawings in the embodiments of the present application.

[0036] The following embodiments of the present application provide a battery pack, which can be used in photovoltaic energy storage systems and other application scenarios.

[0037] For example, a photovoltaic system includes a photovoltaic panel, a direct current / direct current converter, an energy storage container, and a direct current / alternating current converter. The photovoltaic panel is used to convert solar energy into direct current power. The direct current / direct current converter is used to convert the direct current generated by the photovoltaic panel into adjustable direct current, and then output to the energy storage container for storing the power. Generally, in order to increase the capacity of the energy storage container, the energy storage container includes a plurality of battery packs, the energy storage container includes a plurality of battery compartments, each battery compartment includes a battery cluster, and the battery cluster includes a plurality of battery packs stacked. The battery pack includes a plurality of battery cells. High-energy-density battery cells are prone to thermal runaway under conditions such as collision, overheating, extrusion, or needle puncture, and the battery cells will release a large amount of heat and flammable gas in an instant when thermal runaway occurs. In order to prevent the battery pack from burning and exploding due to thermal runaway of the battery cells, an explosion-proof valve is usually installed on the side wall of the battery pack, and a spring-type explosion-proof valve is usually selected to control the opening and closing of the valve body. When the battery pack is in a normal state, the explosion-proof valve is in a normally closed state by the pulling force of the spring. When the battery cells are in thermal runaway, the spring pushes the valve cover of the explosion-proof valve open after a certain pressure is generated in the battery pack, so that the inside of the battery pack is in communication with the outside, and the explosion-proof valve is closed after the pressure in the battery pack is released, reducing the risk of burning and explosion of the battery pack. In practice, the energy storage container also has a smoke exhaust channel, which is in communication with the explosion-proof valve and the battery pack, and is used to discharge the high-temperature gas released by the thermal runaway of the battery pack to the outside of the cabinet.

[0038] However, in the process of thermal runaway of the battery pack, part of the auxiliary materials in the battery pack (for example, plastic structural parts, aluminum bars, plastic insulating parts, etc. of the battery pack, and structural parts, top holding pieces, etc. inside the battery cell) will melt at high temperature, separate from the original fixed position and be blown to the explosion-proof valve port along with the high-speed smoke of thermal runaway, which may block the explosion-proof valve port or cause the explosion-proof valve to deform, resulting in failure of the explosion-proof valve, so that the high-temperature gas inside the battery pack cannot continue to be discharged, and then the whole battery pack catches fire or explodes. Therefore, how to prevent the battery pack from causing the explosion-proof valve to fail during thermal runaway has become a problem to be solved.

[0039] The battery pack 200 provided by the application has the structure shown in FIG. 1-3. FIG. 1 is a structural schematic diagram of the battery pack 200 provided by the application, FIG. 2 is a side structural sectional view of the battery pack 200 provided by the application, and FIG. 3 is an enlarged schematic diagram of the structure at A in FIG. 2. The battery pack 200 comprises a shell 250 for accommodating battery cells, a plurality of battery cells form a battery module 260, and the battery module 260 is located in the shell 250. The shell 250 comprises four side walls and a top wall 251, the four side walls are arranged opposite to each other in pairs, and the top wall 251 is connected with the four side walls. The top wall 251 and the four side walls form an accommodation cavity for accommodating the battery module 260. The wall 251 is one of the four side walls, and the wall 251 can be the rear wall of the battery pack. The wall 251 of the shell 250 is provided with an explosion-proof valve 210. The explosion-proof valve 210 can also be arranged on the top wall 251 according to actual requirements. The inside of the shell 250 is provided with a cover 220, and the battery module 260 and the cover 220 are arranged along the X direction. The X direction can be the length direction of the battery pack 200, or the width direction of the battery pack 200. The Z direction is the height direction of the battery pack 200. The explosion-proof valve 210 comprises a valve body 212 and a valve cover 211. The valve body 212 comprises an inner cavity, and the valve cover 211 is used for sealing the inner cavity. The valve body 212 is provided with a gas vent 213. The gas vent 213 is used for connecting the inner cavity and the inside of the shell. The gas vent 213 is used for connecting the inside and outside of the battery pack 200 after the explosion-proof valve 210 is opened. The high-temperature gas generated by the thermal runaway of the battery module 260 is discharged through the gas vent 213. The inside of the shell 250 is provided with a cover 220, and the cover 220 comprises a first side plate 222. The projection of the first side plate 222 on the wall 251 covers the gas vent 213, and the first side plate 222 is provided with a plurality of first through holes 221. The structure and position of the first through hole 221 can be shown in FIG. 4 and FIG. 5. FIG. 4 is a structural schematic diagram of the wall 251 of the battery pack 200 provided by the application, and FIG. 5 is a structural schematic diagram of the cover 220 of the battery pack 200 provided by the application installed on the wall 251. The cover 220 is arranged between the gas vent 213 of the explosion-proof valve 210 and the battery cell, and the projection of the first side plate 222 in the X direction covers the gas vent 213 of the explosion-proof valve 210. On the one hand, when the battery cell is in thermal runaway, the solid components released by the thermal runaway of the battery cell will flow to the explosion-proof valve 210 along with the high-temperature gas, as shown by the arrow direction in FIG. 3. The first side plate 222 of the cover 220 can block the solid components or electrolyte released by the thermal runaway of the battery cell, so as to prevent the solid components or electrolyte from blocking and damaging the explosion-proof valve 210. On the other hand, the surface of the cover 220 opposite to the battery cell is provided with a plurality of first through holes 221. The high-temperature gas generated by the thermal runaway of the battery cell can be released to the explosion-proof valve 210 through the plurality of first through holes 221, and then released to the outside of the battery pack 200 through the explosion-proof valve 210, so as to ensure the pressure relief effect of the explosion-proof valve 210.

[0040] To further enhance the pressure relief capability of the battery pack 200 when thermal runaway occurs, the sum of the areas of the plurality of first through holes 221 is greater than the pressure relief area of the explosion-proof valve 210. The pressure relief area of the explosion-proof valve 210 is the area through which other gases or liquids can flow after the explosion-proof valve 210 is opened. If the sum of the areas of the plurality of first through holes 221 is less than the pressure relief area of the explosion-proof valve 210 after it is opened, the high-temperature gas, dust, and electrolyte released by the battery cell when the battery pack 200 experiences thermal runaway cannot be discharged from the plurality of first through holes 221 to the explosion-proof valve 210 in time, and may be blocked inside the battery pack 200, causing the internal pressure of the battery pack 200 to fail to drop in time, resulting in a risk of explosion. Therefore, to ensure the pressure relief effect of the explosion-proof valve 210, the sum of the areas of the plurality of first through holes 221 should be greater than or equal to the pressure relief area of the explosion-proof valve 210 after it is opened.

[0041] If the diameter of the first through hole 221 is too large, the solid or electrolyte released by the battery cell when it experiences thermal runaway can be released to the explosion-proof valve 210 through the first through hole 221, which may still block the explosion-proof valve 210, causing the explosion-proof valve 210 to fail. Therefore, the diameter of the first through hole 221 cannot be too large. For example, the diameter of the plurality of first through holes 221 is less than or equal to 10 mm.

[0042] If the diameter of the first through hole 221 is too small, it will cause a large amount of gas generated by the battery pack 200 in a short period of time to be unable to be quickly released outside the battery pack 200. Therefore, the diameter of the plurality of first through holes 221 cannot be too small. For example, the diameter of the plurality of first through holes 221 is greater than or equal to 2 mm.

[0043] The cover 220 can have various shapes. The cover 220 can be a cuboid cavity, a hemispherical cavity, or a polygonal cavity, etc.

[0044] To increase the pressure relief area of the explosion-proof valve 210, the gas passage 213 can be provided in multiple numbers, and the plurality of first through holes 221 and the plurality of gas passages 213 are not overlapped. This design can enhance the blocking effect of the first side plate 222 on the solid components released by the battery cell, preventing the solid components from flying to the explosion-proof valve 210 through the plurality of first through holes 221, and further blocking the gas passage 213.

[0045] In one example, the explosion-proof valve 210 is arranged opposite and spaced apart from the first side plate 222. That is, there is a distance between the first side plate 222 and the explosion-proof valve 210, further enhancing the blocking effect of the cover 220.

[0046] Continuing to refer to FIG. 5, the explosion-proof valve 210 includes a valve body 212 and a valve cover 211 connected to each other, the valve cover 211 is located outside the wall and is spaced apart from the wall, the first side plate 222 is provided with a second through hole 226, the wall 251 is provided with a valve hole, the second through hole 226 is arranged opposite to the valve hole, and the valve body 212 passes through the valve hole and the second through hole 226 in sequence. The valve body 212 is provided with an elastic member 214, and the elastic member 214 is used to move the valve cover 211 away from the wall when the air pressure in the battery pack 200 increases. When thermal runaway occurs inside the battery pack 200, the voltage inside the battery pack 200 will rise sharply, and the elastic member 214 will pop up the valve cover 211, so that the gas inside the battery pack 200 is released to the outside through the gas vent 213 of the explosion-proof valve 210. In this way, the distance between the first side plate 222 and the wall 251 can be shortened while ensuring the blocking effect of the first side plate 222, improving the structural compactness of the components inside the battery pack 200, and improving the energy density of the battery pack 200.

[0047] In an example, the minimum distance between the first side plate 222 and the battery module 260 is greater than 0. That is, there is a gap between the first side plate 222 and the side of the battery module 260 close to the wall 251, and when the battery pack 200 is in thermal runaway, the high-temperature gas released can flow from the gap to the first through hole 221, thereby enhancing the pressure relief capability of the battery pack 200.

[0048] In an example, the minimum distance between the valve body 212 and the battery module 260 is greater than 0. That is, there is a gap between the valve body 212 and the side of the battery module 260 close to the wall 251, and when the battery pack 200 is in thermal runaway, the high-temperature gas released can flow from the gap to the first through hole 221, thereby enhancing the pressure relief capability of the battery pack 200.

[0049] In an example, the cover 220 includes four second side plates 223, the four second side plates 223 are arranged opposite to each other in pairs, the four second side plates 223 are perpendicular to and connected to the first side plate 222, and at least one of the four second side plates 223 is provided with at least one third through hole 224.

[0050] Referring to the structural schematic diagram of the cover 220 shown in FIG. 6, when the cover 220 is a cuboid cavity, the cover 220 can include four second side plates 223, which are arranged opposite to each other in pairs. The four second side plates 223 are perpendicular to the wall 251, and at least one of the four second side plates 223 is provided with at least one third through hole 224. As shown in FIG. 6, a plurality of third through holes 224 are arranged on each of the four second side plates 223. When the battery cell in the battery pack 200 is in thermal runaway, in addition to releasing high-temperature gas, the battery cell also releases dust, melted auxiliary components, etc., which are sprayed with the high-temperature gas to the plurality of first through holes 221, which may block the plurality of first through holes 221, thereby reducing the pressure relief rate of the battery pack 200. Therefore, at least one of the four second side plates 223 of the cover 220 is provided with a third through hole 224, so that when the first through hole 221 is blocked, the high-temperature gas in the battery pack 200 can still be released to the outside through the third through hole 224. Moreover, since the third through hole 224 is provided on the second side plate 223 of the cover 220, the solid components released by the battery cell will not fly to the explosion-proof valve 210 through the third through hole 224, so as to block the explosion-proof valve 210 inside the cover 220.

[0051] The four second side plates 223 of the cover 220 include one second side plate 223, i.e., the bottom surface of the cover 220, which is arranged opposite to the bottom wall of the battery pack 200, and the third through hole 224 is arranged on the second side plate 223 of the cover 220. When the solid components released by the battery cell in thermal runaway enter the cover 220 through the first through hole 221, they can fall to the bottom wall of the battery pack 200 through the third through hole 224 on the bottom surface, thereby preventing them from blocking the explosion-proof valve 210.

[0052] It should be understood that the sum of the areas of the at least one third through hole 224 is greater than the pressure relief area of the explosion-proof valve 210. If the sum of the areas of the at least one third through hole 224 is less than the pressure relief area of the explosion-proof valve 210 after being opened, the high-temperature gas, dust and electrolyte released by the battery cell when the battery pack 200 is in thermal runaway cannot be discharged to the explosion-proof valve 210 in time through the plurality of first through holes 221, and may be blocked inside the battery pack 200, thereby causing the air pressure inside the battery pack 200 to fail to drop in time, resulting in the risk of explosion. Therefore, in order to ensure the pressure relief effect of the explosion-proof valve 210, the sum of the areas of the plurality of vent holes should be greater than or equal to the pressure relief area of the explosion-proof valve 210 after being opened.

[0053] It should be understood that, in order to further enhance the pressure relief capability of the battery pack 200, the aperture area of the third through hole 224 is greater than or equal to 2 mm.

[0054] The cover 220 includes two fixed arms 225 parallel to the first side plate 222, two fixed arms 225 are respectively connected with two opposite second side plates 223 of the four second side plates 223, and the two fixed arms 225 are fixedly connected with the wall 251. A plurality of screw holes can be provided on the fixed arm 225, and the cover 220 and the wall 251 of the battery pack 200 are fixedly connected through the cooperation of the screw holes and the bolts. The stability of the connection between the cover 220 and the wall 251 of the battery pack 200 is enhanced, and the impact on the cover 220 caused by the thermal runaway of the battery cell is prevented, so that the cover 220 is prevented from falling off. In other examples, the cover 220 can also be fixed by welding, riveting and the like.

[0055] Based on the same inventive concept, the energy storage cabinet includes a plurality of the aforementioned battery packs 200, and the plurality of battery packs 200 are stacked in the energy storage cabinet. Since the cover 220 is arranged inside the battery pack 200, the solid components or electrolyte released after the thermal runaway of the battery cell can be prevented from blocking or damaging the explosion-proof valve 210, thereby improving the safety and stability of the energy storage cabinet.

[0056] The energy storage cabinet also includes a smoke exhaust passage extending along the stacking direction of the plurality of battery packs 200, the smoke exhaust passage includes a plurality of smoke inlets and smoke outlets, the explosion-proof valves 210 of the plurality of battery packs 200 correspond one-to-one to the plurality of smoke inlets, and the plurality of battery packs 200 are in communication with the smoke exhaust passage after the explosion-proof valves 210 of the plurality of battery packs 200 are opened. When the battery pack 200 undergoes thermal runaway, the explosion-proof valve 210 of the battery pack 200 is opened, and the high-temperature gas released by the battery pack 200 is released into the smoke exhaust passage through the explosion-proof valve 210 and the smoke inlet, and then released to the outside through the smoke outlet.

[0057] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A battery pack, characterized by, The battery pack comprises a shell for accommodating a battery cell, the shell comprises four side walls and a top wall, the four side walls are arranged opposite to each other in pairs, and the top wall is connected with the four side walls; the wall of the shell is provided with an explosion-proof valve, and the wall is any one of the four side walls and the top wall; The explosion-proof valve comprises a valve body and a valve cover, the valve body comprises an inner cavity, the valve cover is used for sealing the inner cavity, and the valve body is provided with a gas passage for communicating the inner cavity with the inside of the shell; The inside of the shell is provided with a cover shell, the cover shell comprises a first side plate, the projection of the first side plate on the wall covers the gas passage, and the first side plate is provided with a plurality of first through holes.

2. The battery pack of claim 1, wherein, The gas passage is a plurality of gas passages, and the plurality of first through holes and the plurality of gas passages are not overlapped.

3. The battery pack of claim 1 or 2, wherein, The explosion-proof valve is opposite to and spaced apart from the first side plate.

4. The battery pack of claim 1 or 2, wherein, The valve cover is located outside the wall and is spaced apart from the wall, the first side plate is provided with a second through hole, the wall is provided with a valve hole, the second through hole is opposite to the valve hole, and the valve body passes through the valve hole and the second through hole in sequence; The inner cavity is provided with an elastic member, and the elastic member is used to move the valve cover away from the wall when the air pressure in the battery pack increases.

5. The battery pack of claim 4, wherein, The battery cell is a plurality of battery cells, and the plurality of battery cells form a battery module; the minimum distance between the first side plate and the battery module is greater than 0.

6. The battery pack of claim 4 or 5, wherein, The battery cell is a plurality of battery cells, and the plurality of battery cells form a battery module; the minimum distance between the valve body and the battery module is greater than 0.

7. The battery pack of claim 4, wherein, The cover shell comprises four second side plates, the four second side plates are arranged opposite to each other in pairs, the four second side plates are perpendicular to and connected with the first side plate, and at least one of the four second side plates is provided with at least one third through hole.

8. The battery pack of claim 7, wherein, One of the four second side plates is opposite to the bottom wall of the battery pack, and the one second side plate is provided with at least one third through hole.

9. The battery pack of claim 1 or 2, wherein, The sum of the areas of the plurality of first through holes is greater than the pressure relief area of the explosion-proof valve.

10. The battery pack of claim 7 or 8, wherein, The sum of the areas of the at least one third through hole is greater than the pressure relief area of the explosion-proof valve.

11. The battery pack of claim 7 or 8, wherein, The cover shell comprises two fixing arms, the two fixing arms are parallel to the first side plate, the two fixing arms are connected with two opposite second side plates of the four second side plates respectively, and the two fixing arms are fixedly connected with the wall.

12. An energy storage cabinet characterized by, The energy storage cabinet comprises a plurality of battery packs as claimed in any one of claims 1-11, and the plurality of battery packs are stacked.

13. The energy storage cabinet of claim 12, wherein, The energy storage cabinet comprises a smoke exhaust channel, the smoke exhaust channel extends along the stacking direction of the plurality of battery packs, comprises a plurality of smoke inlets and a smoke outlet, the explosion-proof valves of the plurality of battery packs correspond to the plurality of smoke inlets one by one, and the plurality of battery packs are communicated with the smoke exhaust channel after the explosion-proof valves of the plurality of battery packs are opened.

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