Battery pack and energy storage system

Abstract

This application provides a battery pack and energy storage system. The battery pack includes a housing for housing battery cells, and an explosion-proof valve is provided on the wall of the housing. It includes a valve body and a valve cover. The valve body includes an inner cavity, and the valve cover seals the inner cavity. The valve body has a vent for connecting the inner cavity and the interior of the housing. A cover is provided inside the housing, and the cover includes a first side plate. The projection of the first side plate onto the wall covers the vent, and the first side plate has multiple first through holes. When a battery cell experiences thermal runaway, the solid components released by the cell flow towards the explosion-proof valve along with the high-temperature gas. The first side plate of the cover can block the solid components or electrolyte released during thermal runaway, preventing them from clogging or damaging the explosion-proof valve. Simultaneously, the high-temperature gas generated by the thermal runaway of the cell can be released through the multiple first through holes to the explosion-proof valve, and then released to the outside of the battery pack through the explosion-proof valve, ensuring the pressure relief capability of the battery pack.

Description

[0001] This application claims priority to Chinese Patent Application No. 202421530073.7, filed on June 28, 2024, entitled “A Battery Pack and Energy Storage System”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of energy storage technology, and in particular to a battery pack and energy storage system. Background Technology

[0003] Battery packs are widely used in energy storage systems. In these systems, electrical energy is stored and supplied to users through the charging and discharging of the battery pack. The battery cell is the basic unit within the battery pack that converts chemical energy into electrical energy. As the energy density of battery cells continues to increase, their safety becomes increasingly prominent. High-energy-density cells are prone to thermal runaway under conditions such as impact, overheating, compression, or puncture. Furthermore, a cell releasing a large amount of heat and flammable gases at the moment of thermal runaway can trigger a chain reaction of thermal runaway in numerous cells, potentially leading to a battery pack fire or even an explosion.

[0004] During thermal runaway, the cells inside the battery pack generate high-temperature gases. The battery pack's explosion-proof valve opens, and these gases are rapidly released to the outside, reducing the risk of combustion and explosion. However, during thermal runaway, some auxiliary materials within the battery pack (such as plastic structural components, aluminum busbars, plastic insulation, and internal structural components of the cells, such as top support plates) melt at high temperatures. These materials detach from their original positions and are blown towards the explosion-proof valve opening by the high-speed thermal runaway gases. This may block the valve opening or cause it to deform and malfunction, preventing the high-temperature gases inside the battery pack from escaping and potentially leading to a fire or explosion of the entire battery pack. Utility Model Content

[0005] This application provides a battery pack with a cover installed on the wall of the battery pack where the explosion-proof valve is located. The cover is located inside the battery pack. On the one hand, the cover is provided with a plurality of first through holes for the flow of high-temperature gas released by thermal runaway of the battery cells. On the other hand, the cover can block solid components and electrolyte released by thermal runaway of the battery pack, preventing foreign objects from clogging the explosion-proof valve.

[0006] Firstly, this application provides a battery pack, the battery pack including a housing for accommodating battery cells. The housing includes four side walls and a top wall, the four side walls being arranged opposite each other in pairs, and the top wall being connected to the four side walls. The top wall and the four side walls form a receiving cavity for accommodating the battery cells. An explosion-proof valve is provided on one of the four side walls and the top wall. The explosion-proof valve includes a valve body and a valve cover. The valve body includes an inner cavity, and the valve cover is used to seal the inner cavity. The valve body is provided with a vent for connecting the inner cavity and the interior of the housing. When the internal pressure of the battery pack increases and the explosion-proof valve opens, the high-temperature gas released by the battery pack can be discharged to the outside of the battery pack through the vent. A cover is provided inside the housing, the cover including a first side plate. The projection of the first side plate on the wall covers the vent, and the first side plate is provided with multiple first through holes. When a battery cell experiences thermal runaway, the solid components released during this event flow with the high-temperature gas toward the explosion-proof valve. The casing can block these released solid components or electrolyte, preventing them from clogging the vents of the explosion-proof valve and suppressing gas release from inside the battery pack, thus preventing a battery pack explosion. Simultaneously, the high-temperature gas generated by the thermal runaway can be released through multiple primary through-holes to the explosion-proof valve, and then through the valve to the outside of the battery pack, ensuring the battery pack's pressure relief capability.

[0007] In one possible implementation, there are multiple vents, and the multiple first through holes and the multiple vents are arranged without overlap. This can enhance the blocking effect of the first side plate on solid components released from the battery cell, preventing solid components from flying towards the explosion-proof valve through the multiple first through holes and thus blocking the vents.

[0008] In one possible implementation, the explosion-proof valve is positioned opposite and spaced apart from the first side plate. By positioning the explosion-proof valve and the first side plate opposite each other, the explosion-proof valve can be completely prevented from being exposed to the outer periphery of the battery cell that has experienced thermal runaway. This enhances the blocking effect of the first side plate on solid components released during thermal runaway of the battery cell, thereby preventing solid components released by the thermally runaway battery cell from flying towards the explosion-proof valve.

[0009] In one possible implementation, the valve cover is located outside the wall and spaced apart from it. A second through-hole is provided on the first side plate, and a valve hole is provided on the wall for installing an explosion-proof valve. The second through-hole is opposite to the valve hole, and the valve body passes through the valve hole and the second through-hole sequentially. An elastic element is provided inside the valve body, which is used to move the valve cover away from the wall when the gas pressure inside the battery pack increases. When thermal runaway occurs in the battery pack, the voltage inside the battery pack will rise sharply, and the elastic element will spring up the valve cover, allowing the gas inside the battery pack to be released to the outside through the vent of the explosion-proof valve. This can shorten the distance between the first side plate and the wall while ensuring the blocking effect of the first side plate, improving the structural compactness of the internal components of the battery pack, and increasing the energy density of the battery pack.

[0010] In one possible implementation, there are multiple battery cells, which together form a battery module. The minimum distance between the first side plate and the battery module is greater than zero. A gap exists between the first side plate and the side of the battery module closest to the wall. When thermal runaway occurs in the battery pack, the released high-temperature gas can flow through this gap to the first through-hole, enhancing the pressure relief capability of the battery pack.

[0011] In one possible implementation, there are multiple battery cells, which together form a battery module. The minimum distance between the valve body and the battery module is greater than zero. A gap exists between the valve body and the side of the battery module closest to the wall. When thermal runaway occurs in the battery pack, the released high-temperature gas can flow through this gap to the first through-hole, enhancing the pressure relief capability of the battery pack.

[0012] In one possible implementation, the casing includes four second side plates, which are arranged opposite each other in pairs. The four second side plates are perpendicular to and connected to the first side plate, and at least one of the four second side plates has at least one third through hole. If the solid components released during thermal runaway of the battery cell block the first through hole of the first side plate of the casing, the high-temperature gas released during thermal runaway of the battery cell can still 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 one possible implementation, one of the four second side plates is disposed opposite to the bottom wall of the battery pack, and the second side plate is provided with at least one of the third through holes. When a cell experiences thermal runaway, the released solid components enter the casing through the first through hole, and can then fall onto the bottom wall of the battery pack through the third through hole of the second side plate, preventing them from clogging the explosion-proof valve.

[0014] In one possible implementation, 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 thermal runaway occurs in the battery cell, the generated high-temperature gas can be released to the outside of the battery pack in a timely manner through the plurality of first through holes and the explosion-proof valve, ensuring the pressure relief effect of the battery pack.

[0015] In one possible implementation, the diameter of each of the plurality of first through holes is greater than or equal to 2 mm. This prevents the high-temperature gas generated by thermal runaway of the battery cell from accumulating inside the battery pack due to an excessively small diameter of the first through holes, thus ensuring the pressure relief effect of the battery pack.

[0016] In one possible implementation, the diameter of each of the plurality of first through holes is less than or equal to 10 mm. This prevents the solid components released from the battery cell from being released into the casing through the first through hole if the diameter of the first through hole is too large, thereby blocking the explosion-proof valve.

[0017] In one possible implementation, 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. This ensures timely release of high-temperature gas from inside the battery pack to the outside, guaranteeing the effective pressure relief of the battery pack.

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

[0019] In one possible implementation, the housing includes two fixing arms parallel to the first side plate. The two fixing arms are respectively connected to two of the four opposing second side plates. The two fixing arms are fixedly connected to the wall, thereby enhancing the stability of the connection between the housing and the side wall of the battery pack.

[0020] Secondly, this application provides an energy storage cabinet, which includes multiple battery packs as described in the first aspect, and the multiple battery packs are stacked. Because a casing is provided inside the battery pack, solid components or electrolyte released after thermal runaway of the battery cells can be prevented from clogging or damaging the explosion-proof valve, thereby improving the safety and stability of the energy storage cabinet.

[0021] In one possible implementation, a smoke exhaust channel extends along the stacking direction of the multiple battery packs. The smoke exhaust channel includes multiple smoke inlets and smoke outlets. Explosion-proof valves of the multiple battery packs correspond one-to-one with the multiple smoke inlets. After the explosion-proof valves of the multiple battery packs are opened, the multiple battery packs are connected to the smoke exhaust channel. When a battery pack experiences thermal runaway, the high-temperature gases released by the battery pack can be discharged into the smoke exhaust channel through the smoke inlets, and then discharged to the outside of the energy storage cabinet through the smoke outlets of the smoke exhaust channel, reducing the risk of combustion and explosion of the energy storage cabinet. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a battery pack provided in an embodiment of this application;

[0023] Figure 2 This is a side structural cross-sectional view of a battery pack provided in an embodiment of this application;

[0024] Figure 3 yes Figure 2 Enlarged schematic diagram of the structure at point A;

[0025] Figure 4 This is a front view of the wall of the battery pack provided in the embodiment of this application;

[0026] Figure 5 This is a schematic diagram of the structure of the battery pack cover installed inside the housing according to an embodiment of this application;

[0027] Figure 6 This is a schematic diagram of a battery pack casing provided in an embodiment of this application.

[0028] Figure Labels

[0029] 200-Battery pack; 210-Explosion-proof valve; 211-Valve cover; 212-Valve body; 213-Ventilation port; 214-Elastic element; 220-Cover; 221-First through hole; 222-First side plate; 223-Second side plate; 224-Third through hole; 225-Fixing arm; 226-Second through hole; 250-Housing; 251-Wall; 252-Top wall 251; 260-Battery module 260. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. However, the exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein. The same reference numerals in the figures denote the same or similar structures, and therefore repeated descriptions of them will be omitted. The terms expressing position and direction described in the embodiments of this application are illustrative based on the accompanying drawings, but changes can be made as needed, and all such changes are included within the scope of protection of this application. The accompanying drawings of the embodiments of this application are for illustrating relative positional relationships only and do not represent actual scale.

[0031] In the embodiments of this application, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0032] It should be noted that specific details are set forth in the following description to facilitate understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0033] For ease of understanding, the terminology used in the embodiments of this application will be explained first.

[0034] Multiple: refers to two or more.

[0035] The term "connection" should be interpreted broadly. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. Similarly, "fixation" should also be interpreted broadly. For example, "fixation" can be direct fixation or indirect fixation through an intermediate medium.

[0036] The embodiments of this application are described below with reference to the accompanying drawings.

[0037] The following embodiments of this application provide a battery pack that can be used in applications such as photovoltaic energy storage systems.

[0038] For example, a photovoltaic (PV) system includes PV panels, DC / DC converters, energy storage containers, and DC / AC converters. PV panels convert solar energy into DC power. DC / DC converters convert the DC power generated by the PV panels into adjustable DC power, which is then output to the energy storage container for storage. Generally, to increase the capacity of an energy storage container, it includes multiple battery packs, multiple battery compartments, each containing a battery cluster, and multiple stacked battery packs. Each battery pack contains multiple battery cells. High-energy-density battery cells are prone to thermal runaway under conditions such as impact, overheating, compression, or puncture. Furthermore, a battery cell releases a large amount of heat and flammable gas at the moment of thermal runaway. To prevent the battery pack from exploding due to thermal runaway of the cells, explosion-proof valves are usually installed on the side walls of the battery pack. Spring-loaded explosion-proof valves are typically chosen, with a spring structure controlling the opening and closing of the valve. When the battery pack is in normal condition, the spring tension keeps the explosion-proof valve in a normally closed state. In the event of thermal runaway of a battery cell, a certain pressure is generated inside the battery pack, causing a spring to push open the cover of the explosion-proof valve, thus connecting the inside of the battery pack with the outside. The valve closes after the internal pressure is released, reducing the risk of combustion and explosion. In practice, energy storage containers are also equipped with exhaust ducts, which are connected to the battery pack via explosion-proof valves. These exhaust ducts are used to vent the high-temperature gases released during thermal runaway of the battery pack outside the container.

[0039] However, during thermal runaway of a battery pack, some auxiliary materials (such as plastic structural components, aluminum busbars, plastic insulation components, and internal structural components of the cells, such as top support plates) melt at high temperatures. These materials detach from their original positions and are blown towards the explosion-proof valve port by the high-speed runaway gases. This can clog the valve port or cause it to deform, leading to valve failure. Consequently, the high-temperature gases inside the battery pack cannot escape, potentially causing the entire battery pack to catch fire or explode. Therefore, preventing the explosion-proof valve from failing during thermal runaway is a pressing issue that needs to be addressed.

[0040] This application provides a battery pack 200, the structure of which can be referred to. Figures 1-3 As shown. Figure 1 This is a schematic diagram of the structure of the battery pack 200 provided in this application. Figure 2 This is a side structural cross-sectional view of the battery pack 200 provided in this application. Figure 3 for Figure 2 An enlarged schematic diagram of the structure at point A. The battery pack 200 includes a housing 250, which houses the battery cells. Multiple battery cells form a battery module 260, which is located within the housing 250. The housing 250 includes four side walls and a top wall 251. The four side walls are arranged in pairs opposite each other, and the top wall 251 is connected to all four side walls, forming a receiving cavity for accommodating the battery module 260. Wall 251 is one of the four side walls and can be the rear wall of the battery pack. Wall 251 of the housing 250 has an explosion-proof valve 210. The explosion-proof valve 210 can also be located on the top wall 251 according to actual needs. A cover 220 is provided inside the housing 250. The battery module 260 and the cover 220 are arranged along the X direction, which can be the length or width of the battery pack 200. The Z direction is the height of the battery pack 200. The explosion-proof valve 210 includes a valve body 212 and a valve cover 211. The valve body 212 includes an inner cavity, and the valve cover 211 is used to seal the inner cavity. The valve body 212 is provided with a vent 213, which is used to connect the inner cavity and the interior of the housing. The vent 213 is used to connect the interior and exterior of the battery pack 200 after the explosion-proof valve 210 is opened, and the high-temperature gas generated by the thermal runaway of the battery module 260 is discharged through the vent 213. A cover 220 is provided inside the housing 250. The cover 220 includes a first side plate 222. The projection of the first side plate 222 on the wall 251 covers the vent 213. The first side plate 222 is provided with multiple first through holes 221. The structure and position of the first through holes 221 can be found in [reference needed]. Figure 4 and Figure 5 As shown. Figure 4 This is a schematic diagram of the structure of wall 251 of the battery pack 200 provided in this application. Figure 5This is a schematic diagram of the structure of the battery pack 200 provided in this application embodiment, with the casing 220 mounted on the wall 251. The casing 220 is disposed between the 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 vent 213 of the explosion-proof valve 210. On the one hand, when the battery cell experiences thermal runaway, the solid components released by the thermal runaway will flow towards the explosion-proof valve 210 along with the high-temperature gas, such as... Figure 3 As indicated by the arrow in the diagram. The first side plate 222 of the casing 220 can block solid components or electrolyte released during thermal runaway of the battery cell, preventing them from clogging or damaging the explosion-proof valve 210. On the other hand, the surface of the casing 220 opposite to the battery cell is provided with multiple first through holes 221. The high-temperature gas generated during thermal runaway of the battery cell can be released through the multiple first through holes 221 to the explosion-proof valve 210, and then released to the outside of the battery pack 200 through the explosion-proof valve 210, ensuring the pressure relief effect of the explosion-proof valve 210.

[0041] To further enhance the pressure relief capability of the battery pack 200 in the event of thermal runaway, the sum of the areas of the multiple 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 substances or liquids can flow after the explosion-proof valve 210 is opened. If the sum of the areas of the multiple first through holes 221 is less than the pressure relief area of ​​the explosion-proof valve 210 after it is opened, then when the battery pack 200 experiences thermal runaway, the high-temperature gas, dust, and electrolyte released by the cells cannot be discharged to the explosion-proof valve 210 in time through the multiple first through holes 221, and may become blocked inside the battery pack 200, causing the internal pressure of the battery pack 200 to fail to drop in time, leading to a risk of combustion and explosion. Therefore, to ensure the pressure relief effect of the explosion-proof valve 210, the sum of the areas of the multiple 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.

[0042] If the diameter of the first through hole 221 is too large, the solids or electrolyte released during thermal runaway of the battery cell will be released through the first through hole 221 to the explosion-proof valve 210, which may still block the explosion-proof valve 210 and cause it to fail. Therefore, the diameter of the first through hole 221 cannot be too large. For example, the diameter of multiple first through holes 221 should be less than or equal to 10 mm.

[0043] If the diameter of the first through hole 221 is too small, the large amount of gas generated by the battery pack 200 in a short period of time will not be able to be released quickly outside the battery pack 200. Therefore, the diameter of the multiple first through holes 221 cannot be too small. For example, the diameter of the multiple first through holes 221 is greater than or equal to 2 mm.

[0044] The cover 220 can have various shapes. The cover 220 can be a cuboid cavity, a hemispherical cavity, or a polygonal cavity, etc.

[0045] To increase the pressure relief area of ​​the explosion-proof valve 210, multiple vents 213 can be provided, with multiple first through holes 221 and multiple vents 213 arranged without overlap. This design can enhance the blocking effect of the first side plate 222 on solid components released from the battery cell, preventing solid components from flying towards the explosion-proof valve 210 through the multiple first through holes 221 and thus blocking the vents 213.

[0046] In one example, the explosion-proof valve 210 is positioned 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, which further enhances the blocking effect of the cover 220.

[0047] See also Figure 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 on the outside of the wall and spaced apart from the wall. A second through hole 226 is provided on the first side plate 222. A valve hole is provided on the wall 251. The second through hole 226 is arranged opposite to the valve hole. The valve body 212 passes through the valve hole and the second through hole 226 in sequence. An elastic element 214 is provided inside the valve body 212. The elastic element 214 is used to move the valve cover 211 away from the wall when the gas pressure inside the battery pack 200 increases. When thermal runaway occurs inside the battery pack 200, the voltage inside the battery pack 200 will increase sharply. The elastic element will bounce the valve cover 211 up, allowing the gas inside the battery pack 200 to be released to the outside through the vent 213 of the explosion-proof valve 210. This design can shorten the distance between the first side plate 222 and the wall 251 while ensuring the blocking effect of the first side plate 222, improving the structural compactness of the internal components of the battery pack 200, and increasing the energy density of the battery pack 200.

[0048] In one 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 closest to the wall 251. When the battery pack 200 experiences thermal runaway, the released high-temperature gas can flow through this gap to the first through hole 221, thereby enhancing the pressure relief capability of the battery pack 200.

[0049] In one example, the shortest 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 battery module 260 on the side near the wall 251. When the battery pack 200 experiences thermal runaway, the released high-temperature gas can flow through this gap to the first through hole 221, enhancing the pressure relief capability of the battery pack 200.

[0050] In one example, the cover 220 includes four second side plates 223, which are arranged opposite each other in pairs. The four second side plates 223 are perpendicular to and connected to the first side plate 222. At least one of the four second side plates 223 has at least one third through hole 224.

[0051] Reference Figure 6 The schematic diagram of the casing 220 shown illustrates that when the casing 220 is a cuboid cavity, it may include four second side plates 223, which are arranged opposite 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 has at least one third through hole 224. Figure 6 As shown, multiple third through holes 224 are respectively provided on the four second side plates 223. When the battery cells in the battery pack 200 experience thermal runaway, in addition to releasing high-temperature gases, the cells will also release dust, melted auxiliary components, etc. These solids will be sprayed towards the multiple first through holes 221 along with the high-temperature gases, potentially blocking the multiple first through holes 221. At this time, the depressurization rate of the battery pack 200 will be reduced. Therefore, at least one of the four second side plates 223 of the cover 220 is provided with a third through hole 224. When the first through holes 221 are blocked, the high-temperature gases in the battery pack 200 can still be released to the outside through the third through hole 224. Furthermore, 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 cells will not fly towards the explosion-proof valve 210 through the third through hole 224, thus preventing them from being released into the cover 220 and blocking the explosion-proof valve 210.

[0052] The four second side plates 223 of the cover 220 include one second side plate 223, which is the bottom surface of the cover 220. The second side plate 223 of the cover 220 is disposed opposite to the bottom wall of the battery pack 200. A third through hole 224 is provided on the second side plate 223 of the cover 220. When the battery cell experiences thermal runaway, the solid components released enter the cover 220 through the first through hole 221 and can fall onto the bottom wall of the battery pack 200 through the third through hole 224 on the bottom surface, preventing them from blocking the explosion-proof valve 210.

[0053] It should be understood that the sum of the areas of 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 at least one third through-hole 224 is less than the pressure relief area of ​​the explosion-proof valve 210 after it is opened, then when the battery pack 200 experiences thermal runaway, the high-temperature gas, dust, and electrolyte released by the cells cannot be discharged to the explosion-proof valve 210 in time through the multiple first through-holes 221, and may become blocked inside the battery pack 200, causing the internal pressure of the battery pack 200 to fail to drop in time, leading to a risk of combustion and explosion. Therefore, in order to ensure the pressure relief effect of the explosion-proof valve 210, the sum of the areas of the multiple vents should be greater than or equal to the pressure relief area of ​​the explosion-proof valve 210 after it is opened.

[0054] 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.

[0055] The housing 220 includes two fixing arms 225, which are parallel to the first side plate 222. Each fixing arm 225 is connected to two of the four opposing second side plates 223. The fixing arms 225 are also fixedly connected to the wall 251. Multiple screw holes can be provided on the fixing arms 225, and the housing 220 is fixedly connected to the wall 251 of the battery pack 200 through the engagement of the screw holes and bolts. This enhances the stability of the connection between the housing 220 and the wall 251 of the battery pack 200, preventing the housing 220 from detaching due to impact during thermal runaway of the battery cells. In other examples, the housing 220 can also be fixed by welding, riveting, or other methods.

[0056] Based on the same inventive concept, the energy storage cabinet includes multiple battery packs 200 as described above, which are stacked within the cabinet. Because a casing 220 is provided inside each battery pack 200, solid components or electrolyte released after thermal runaway of the battery cells can be prevented from clogging or damaging the explosion-proof valve 210, thus improving the safety and stability of the energy storage cabinet.

[0057] The energy storage cabinet also includes a smoke exhaust duct that extends along the stacking direction of the multiple battery packs 200. The smoke exhaust duct includes multiple smoke inlets and outlets. Each battery pack 200 has an explosion-proof valve 210 corresponding to one of its smoke inlets. After the explosion-proof valves 210 of each battery pack 200 are opened, they connect to the smoke exhaust duct. In the event of thermal runaway in a battery pack 200, the explosion-proof valves 210 of the battery pack 200 open, and the high-temperature gas released from the battery pack 200 is released into the smoke exhaust duct through the explosion-proof valves 210 and the smoke inlets, and then released to the outside through the smoke exhaust outlets.

[0058] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A battery pack, characterized in that, The battery pack includes a housing for accommodating battery cells. The housing includes four side walls and a top wall. The four side walls are arranged opposite each other in pairs. The top wall is connected to the four side walls. The walls of the housing are provided with explosion-proof valves. The wall can be any one of the four side walls and the top wall. The housing has an internal cover, which includes a first side plate. The projection of the first side plate on the wall covers the explosion-proof valve. The first side plate has multiple first through holes.

2. The battery pack according to claim 1, characterized in that, The explosion-proof valve is positioned opposite the first side plate and spaced apart from it.

3. The battery pack according to claim 1, characterized in that, The explosion-proof valve includes a valve body and a valve cover. The valve body has an inner cavity. The valve cover is located on the outside of the wall and is spaced apart from the wall. A second through hole is provided on the first side plate. The wall has a valve hole. The second through hole is opposite to the valve hole. The valve body passes through the valve hole and the second through hole in sequence. The inner cavity is provided with an elastic element, which is used to move the valve cover away from the wall when the air pressure inside the battery pack increases, so as to make the battery pack communicate with the external environment.

4. The battery pack according to any one of claims 1-3, characterized in that, The cover includes four second side plates, which are arranged opposite each other in pairs. The four second side plates are perpendicular to and connected to the first side plate. At least one of the four second side plates has at least one third through hole.

5. The battery pack according to claim 4, characterized in that, One of the four second side plates is disposed opposite to the bottom wall of the battery pack, and the second side plate is provided with at least one of the third through holes.

6. The battery pack according to any one of claims 1-3, characterized in that, The sum of the areas of the plurality of first through holes is greater than the pressure relief area of ​​the explosion-proof valve.

7. The battery pack according to claim 4, characterized in that, 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.

8. The battery pack according to claim 4, characterized in that, The cover includes two fixing arms, which are parallel to the first side plate. The two fixing arms are respectively connected to two of the four second side plates that are arranged opposite to each other. The two fixing arms are fixedly connected to the wall.

9. An energy storage system, characterized in that, The energy storage cabinet includes a plurality of battery packs as described in any one of claims 1-8, and the plurality of battery packs are stacked.

10. The energy storage system according to claim 9, characterized in that, The energy storage cabinet includes a smoke exhaust channel that extends along the stacking direction of the multiple battery packs and includes multiple smoke inlets and smoke outlets. The explosion-proof valves of the multiple battery packs correspond one-to-one with the multiple smoke inlets. After the explosion-proof valves of the multiple battery packs are opened, the multiple battery packs are connected to the smoke exhaust channel.

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