A battery pack

Abstract

The application discloses a battery pack, and relates to the technical field of batteries, which comprises a box frame and a pressure relief body; the pressure relief body comprises a first pressure relief cavity and a second pressure relief cavity which are separated by a heat insulation plate; at least one frame of the box frame is provided with a frame pressure relief cavity, the first pressure relief cavity is communicated with the frame pressure relief cavity through a plurality of first communication holes which are arranged at intervals, the second pressure relief cavity is communicated with the frame pressure relief cavity through a plurality of second communication holes which are arranged at intervals, and the box frame is provided with a box explosion-proof valve which is communicated with the frame pressure relief cavity. The first pressure relief cavity and the second pressure relief cavity are separated by the heat insulation plate, when thermal runaway occurs in a certain single battery in one battery cavity, the heat insulation plate can effectively block the transmission of heat and flame to the other battery cavity, and the risk of thermal runaway spreading is greatly reduced. The influence range of the thermal runaway event is controlled in one battery cavity, the overall failure of the whole battery pack is avoided, and the safety of the system is improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a battery pack. Background Technology

[0002] To improve space utilization, current battery packs are designed with two battery layers stacked together, and a pressure relief chamber is placed between the two battery layers so that the two battery layers can share the pressure relief chamber.

[0003] When a single cell in a battery pack experiences thermal runaway, the resulting high-temperature, high-pressure gas enters the pressure relief chamber and is then discharged from the battery pack to prevent the battery pack from exploding due to high pressure. However, if only one layer of the battery pack experiences thermal runaway, the runaway gas discharged into the pressure relief chamber can cause the temperature of the other layer of the battery pack to rise, subsequently triggering thermal runaway in that other layer.

[0004] Therefore, how to prevent cascading thermal runaway in different battery layers is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0005] In view of this, the purpose of this application is to provide a battery pack to prevent cascading thermal runaway in different battery layers.

[0006] To achieve the above objectives, this application provides the following technical solution:

[0007] A first aspect of this application provides a battery pack, including a battery housing and a battery pack, wherein the battery housing includes a housing frame and a pressure relief body;

[0008] The cavity enclosed by the frame of the housing includes at least a battery cavity for accommodating the battery pack. The pressure relief body is disposed in the battery cavity to divide the battery cavity into a first battery cavity and a second battery cavity along a first direction.

[0009] The pressure relief body includes a first pressure relief chamber and a second pressure relief chamber separated by a heat insulation plate. The first battery chamber contains a first battery pack, and the second battery chamber contains a second battery pack. The explosion-proof valves of the individual cells in the first battery pack and the second battery pack are all facing the pressure relief body. The first pressure relief chamber and the second pressure relief chamber are provided with pressure relief sections for the passage of thermal runaway gas at positions corresponding to the explosion-proof valves of the individual cells. The first pressure relief chamber is the pressure relief channel for the first battery pack, and the second pressure relief chamber is the pressure relief channel for the second battery pack.

[0010] At least one side of the enclosure frame is provided with a frame pressure relief cavity. The first pressure relief cavity is connected to the frame pressure relief cavity through a plurality of first connecting holes arranged at intervals. The second pressure relief cavity is connected to the frame pressure relief cavity through a plurality of second connecting holes arranged at intervals. An explosion-proof valve for the enclosure is provided on the enclosure frame and is connected to the frame pressure relief cavity.

[0011] The battery pack provided in this application has a pressure relief body inside the casing frame. The pressure relief body is divided into a first pressure relief chamber and a second pressure relief chamber by a heat insulation plate, which respectively constitute pressure relief channels for the battery pack in the two battery chambers. At least one side of the casing frame has a side pressure relief chamber. Two pressure relief bodies are connected to the side pressure relief chambers through multiple connecting holes, so that after the thermal runaway of a single battery cell in the battery pack, the pressure can be released through the pressure relief chambers of the pressure relief body and the side pressure relief chambers of the casing frame, breaking through the explosion-proof valve of the casing. The pressure relief body and the casing frame provide a discharge path for the high temperature, high pressure, flammable and explosive gases and particulate matter generated during battery thermal runaway, which can effectively prevent the disorderly diffusion of high temperature ejected materials in the battery casing and avoid the chain reaction of thermal propagation to adjacent normal single cells.

[0012] The first and second pressure relief chambers are separated by a heat insulation plate, preventing heat propagation between them. When a single cell in one of the chambers experiences thermal runaway, the emitted flames and high-temperature materials are confined to the corresponding pressure relief chamber. The heat insulation plate effectively blocks heat and flames from being transferred to the other chamber, significantly reducing the risk of thermal runaway propagation. By controlling the impact of a thermal runaway event within one chamber, the overall failure of the battery pack is avoided, improving system safety.

[0013] The pressure relief chamber is formed directly on the frame of the battery pack, without taking up too much valuable space, making it ideal for battery packs with extremely high space requirements. The battery pack consists of two battery layers that share the central pressure relief chamber, which saves more space and weight compared to designing a separate pressure relief channel for each battery layer.

[0014] The pressure relief chamber on the pressure relief body is connected to the pressure relief chamber on the frame through multiple spaced-apart connecting holes, ensuring that gas enters the frame pressure relief chamber quickly and evenly. When thermal runaway gas enters the larger frame pressure relief chamber from the pressure relief chamber on the pressure relief body, the space increases instantaneously, producing a certain expansion and depressurization effect, making the subsequent depressurization process smoother. The multiple connecting holes also provide redundancy; even if some connecting holes are blocked by ejected material, the other connecting holes still ensure that the pressure relief path remains unobstructed. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a partial structural diagram of the battery pack disclosed in an embodiment of this application;

[0017] Figure 2 This is a schematic diagram of the battery pack disclosed in this application after the battery pack has been removed.

[0018] Figure 3 This is a schematic diagram of the longitudinal section of the battery pack disclosed in an embodiment of this application;

[0019] Figure 4 This is a schematic diagram of the longitudinal section of a battery pack disclosed in another embodiment of this application;

[0020] Figure 5 This is a schematic cross-sectional view of the battery pack disclosed in an embodiment of this application;

[0021] Figure 6 This is a schematic diagram of the structure of the pressure relief body disclosed in the embodiments of this application;

[0022] Figure 7 This is a cross-sectional view of the pressure relief body disclosed in the embodiments of this application.

[0023] The meanings of the various reference numerals in the figure are as follows:

[0024] 100-Battery housing; 110-Housing frame; 111-Frame pressure relief chamber; 1111-First frame pressure relief chamber; 1112-Second frame pressure relief chamber; 112-First connecting hole; 113-Second connecting hole; 114-Partition plate; 120-Housing explosion-proof valve; 130-Pressure relief body; 131-First pressure relief chamber; 1311-First side plate hole; 132-Second pressure relief chamber; 1321-Second side plate hole; 133-Heat insulation plate; 1331-Heat insulation coating; 134-First support plate; 1341-First pressure relief part; 135-Second support plate; 1351-Second pressure relief part; 136-First reinforcing rib; 137-Second reinforcing rib; 140-Mica sheet;

[0025] 200 - First battery pack;

[0026] 300 - Second battery pack. Detailed Implementation

[0027] This application discloses a battery pack to prevent cascading thermal runaway in different battery layers.

[0028] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] The battery explosion-proof valve of a single battery cell is a key component for ensuring battery safety, playing a crucial role in responding to abnormal conditions. A single battery cell can store chemical energy and controllably convert it into electrical energy. In recyclable single batteries, the active materials can be reactivated through charging after discharge, allowing for continued use. A single battery cell generally consists of a casing and a battery cell housed within the casing.

[0030] A battery explosion-proof valve is a component or part that can be actuated to release internal pressure or temperature when the internal pressure or temperature of a single battery reaches a predetermined threshold. During the use of a single battery, the battery explosion-proof valve is mainly used to prevent excessive increase in internal pressure, which could cause deformation or explosion of the single battery, in the event of thermal runaway or other situations. It allows gas to escape from the battery, thereby reducing the internal pressure.

[0031] The materials used for battery explosion-proof valves are not limited, including but not limited to aluminum, steel, alloys, etc. The shapes of battery explosion-proof valves are not limited, such as square, oblong, elliptical, racetrack-shaped, etc. The types of battery explosion-proof valves are not limited, such as scored explosion-proof valves, which can be formed by stamping or laser etching.

[0032] When a single battery cell generates a large amount of heat and gas due to overcharging, over-discharging, short circuits, or other reasons, causing the internal pressure to rise sharply to a certain threshold, the battery explosion-proof valve will open under pressure to release the gas and heat inside the single battery cell, thereby reducing the internal pressure of the single battery cell and preventing serious safety accidents such as explosion or rupture due to excessive internal pressure.

[0033] To allow thermal runaway gases to escape from the battery pack, a pressure relief body is required, with a pressure relief chamber on it. The pressure relief body has a pressure relief zone corresponding to the battery's explosion-proof valve location. This pressure relief zone typically has a pressure relief hole, allowing the thermal runaway gases to enter the pressure relief chamber through the pressure relief valve and then escape from the battery pack through the pressure relief chamber.

[0034] When a battery pack has two battery layers, and the two battery layers share a common pressure relief chamber, if only one battery layer experiences thermal runaway, the thermal runaway gas discharged into the pressure relief chamber will cause the temperature of the other battery layer to rise, which in turn will trigger thermal runaway in the other battery layer.

[0035] Based on this, embodiments of this application disclose a battery pack, such as... Figures 1-5 As shown, the battery pack includes a battery housing 100 and a battery pack (the battery pack can be a cylindrical battery pack or a prismatic battery pack). The battery housing 100 includes a housing frame 110 and a pressure relief body 130.

[0036] The cavity enclosed by the casing frame 110 includes at least a battery cavity for accommodating the battery pack. It should be noted that the cavity enclosed by the casing frame 110 may also include an electrical cavity in addition to the battery cavity. A pressure relief body 130 is disposed within the battery cavity to divide the battery cavity into a first battery cavity and a second battery cavity along a first direction. When the battery pack is placed on a horizontal plane, the first direction can be vertical, so that the first battery cavity and the second battery cavity are vertically distributed.

[0037] It should be noted that the pressure relief body 130 can be welded to the box frame 110, or it can be designed as an integral structure with the box frame 110, or it can be fixed to the box frame 110 through other connection methods. This embodiment does not limit the connection relationship between the pressure relief body 130 and the box frame 110.

[0038] The pressure relief body 130 includes a first pressure relief chamber 131 and a second pressure relief chamber 132 separated by a heat insulation plate 133. The first pressure relief chamber 131 serves as a pressure relief channel for the battery pack within the first battery chamber, and the second pressure relief chamber 132 serves as a pressure relief channel for the battery pack within the second battery chamber. For ease of understanding, the battery pack within the first battery chamber is defined as the first battery pack 200, and the battery pack within the second battery chamber is defined as the second battery pack 300. The first pressure relief chamber 131 serves as a pressure relief channel for the first battery pack 200; after a single cell in the first battery pack 200 experiences thermal runaway, the thermal runaway gas will be released through the first pressure relief chamber 131. The second pressure relief chamber 132 serves as a pressure relief channel for the second battery pack 300; after a single cell in the second battery pack 300 experiences thermal runaway, the thermal runaway gas will be released through the second pressure relief chamber 132.

[0039] The first pressure relief chamber 131 and the second pressure relief chamber 132 are separated by the heat insulation plate 133, so that the first pressure relief chamber 131 and the second pressure relief chamber 132 are not directly connected. The thermal runaway gas in the first pressure relief chamber 131 will not pass through the heat insulation plate 133 and enter the second pressure relief chamber 132, and vice versa.

[0040] The first battery pack 200 includes multiple first individual cells, and the second battery pack 300 includes multiple second individual cells. The explosion-proof valves of the first individual cells and the second individual cells are both oriented toward the pressure relief body 130.

[0041] The first pressure relief chamber 131 and the second pressure relief chamber 132 are respectively provided with pressure relief sections for the passage of thermal runaway gas at the positions corresponding to the battery explosion-proof valve of the first individual battery. For ease of understanding, the pressure relief section provided at the position corresponding to the battery explosion-proof valve of the first individual battery in the first pressure relief chamber 131 is defined as the first pressure relief section 1341, and the pressure relief section corresponding to the battery explosion-proof valve of the second individual battery in the second pressure relief chamber 132 is defined as the second pressure relief section 1351. The first pressure relief section 1341 can be a pressure relief hole or a thinned section; similarly, the second pressure relief section 1351 can be a pressure relief hole or a thinned section. A thinned section refers to a section with a relatively thin thickness, which can be broken through when the battery explosion-proof valve is opened to relieve pressure, causing the thinned section to collapse and deform, thus completing the pressure relief.

[0042] At least one side of the enclosure frame 110 is provided with a frame pressure relief chamber 111. A first pressure relief chamber 131 is connected to the frame pressure relief chamber 111 through a plurality of first connecting holes 112 arranged at intervals. A second pressure relief chamber 132 is connected to the frame pressure relief chamber 111 through a plurality of second connecting holes 113 arranged at intervals. An enclosure explosion-proof valve 120 is provided on the enclosure frame 110 and is connected to the frame pressure relief chamber 111.

[0043] The battery pack explosion-proof valve 120 is a component that is actuated to release internal pressure or temperature when the internal pressure or temperature of the battery pack reaches a predetermined threshold. The explosion-proof valve 120 is used to prevent the risk of explosion caused by abnormal conditions such as battery overheating or overcharging, ensuring the safe operation of the battery. When the battery is operating normally, the explosion-proof valve 120 seals the battery pack 100 to ensure normal battery operation; in the event of thermal runaway, the explosion-proof valve 120 needs to activate its explosion-proof function promptly to release internal gases and heat, thereby reducing the risk of explosion.

[0044] The working principle of the explosion-proof valve 120 is to establish a regulating venting channel inside the battery box 100. When the internal pressure of the battery box 100 increases, the explosion-proof valve 120 opens, allowing gas to be released from the battery box 100, thereby reducing the pressure. The explosion-proof valve 120 may include a housing, a valve cover, and a hinge structure. The explosion-proof valve 120 can be made of metal or flame-retardant polymer materials such as polyvinyl chloride, polyvinylidene chloride, and fluoroplastics.

[0045] The location of the explosion-proof valve 120 in the battery box can be carefully designed according to the overall vehicle layout. For example, it can be placed outside the vehicle collision protection zone, behind the wheels, or in a direction that is unlikely to cause secondary harm to critical vehicle components (such as high-voltage wiring harnesses and other controllers) and pedestrians. If thermal runaway is accompanied by open flame, the explosion-proof valve 120 can guide the flame to a predetermined direction, preventing the flame from directly burning other components inside the battery box or causing other weak parts of the battery box to be burned through. In summary, the battery pack disclosed in this application embodiment has a pressure relief body 130 provided inside the box frame 110. The pressure relief body 130 is divided into a first pressure relief chamber 131 and a second pressure relief chamber 132 by a heat insulation plate 133, so as to form pressure relief channels for the battery pack in the two battery chambers respectively. At least one side of the housing frame 110 is provided with a frame pressure relief chamber 111. Two pressure relief bodies 130 are respectively connected to the frame pressure relief chamber 111 through multiple connecting holes (first connecting hole 112, second connecting hole 113), so that after the thermal runaway of a single cell in the battery pack, the pressure can be released through the pressure relief chambers (first pressure relief chamber 131 and second pressure relief chamber 132) of the pressure relief body 130 and the frame pressure relief chamber 111 of the housing frame 110 to break through the housing explosion-proof valve 120. The pressure relief body 130 and the housing frame 110 provide a discharge path for the high temperature, high pressure, flammable and explosive gases and particulate matter generated during battery thermal runaway, which can effectively prevent the disorderly diffusion of high temperature ejected materials in the battery housing and avoid the chain reaction of thermal spread to adjacent normal single cells.

[0046] The first pressure relief chamber 131 and the second pressure relief chamber 132 are separated by a heat insulation plate 133, which prevents heat propagation between the first and second battery chambers. When a single cell in one of the battery chambers experiences thermal runaway, the emitted flames and high-temperature substances are confined within the corresponding pressure relief chamber. The heat insulation plate 133 effectively blocks the transfer of heat and flames to the other battery chamber, greatly reducing the risk of thermal runaway propagation. By controlling the impact of the thermal runaway event within one battery chamber, the overall failure of the entire battery pack is avoided, improving system safety.

[0047] The pressure relief chamber 111 is formed directly on the frame 110 of the housing, without taking up too much valuable space, making it ideal for battery packs with extremely high space requirements. The battery pack consists of two battery packs that share the central pressure relief chamber 130, which saves more space and weight compared to designing a separate pressure relief channel for each battery pack.

[0048] The pressure relief chamber on the pressure relief body 130 is connected to the frame pressure relief chamber 111 via multiple spaced-apart connecting holes, ensuring that gas enters the frame pressure relief chamber 111 quickly and uniformly. When thermal runaway gas enters the larger frame pressure relief chamber 111 from the pressure relief chamber on the pressure relief body 130, the space increases instantaneously, resulting in a certain expansion and depressurization effect, making the subsequent depressurization process smoother. The multiple connecting holes also provide redundancy; even if some connecting holes are blocked by ejected material, the other connecting holes can still ensure that the pressure relief path is unobstructed. In addition, by only opening multiple connecting holes on the pressure relief body 130 and the frame, the problem of excessive reduction in the strength of the pressure relief body 130 and the frame due to direct hollowing out can be prevented.

[0049] If one battery pack experiences extremely severe thermal runaway, it will eject not only high-temperature gases but also potentially large amounts of flames and high-temperature particles. These substances, within the common frame pressure relief chamber 111, may impact or preheat the explosion-proof valve 120 of the corresponding battery pack. Even if the explosion-proof valve 120 is not open, prolonged exposure to high temperatures may weaken its performance or, in extreme cases, pose a safety risk to another normal battery pack.

[0050] like Figure 4 As shown, in this embodiment, a partition 114 can be provided inside the frame pressure relief cavity 111. The partition 114 divides the frame pressure relief cavity 111 into a first frame pressure relief cavity 1111 and a second frame pressure relief cavity 1112 along a first direction. The partition 114 can divide the frame pressure relief cavity 111 into two cavities (the first frame pressure relief cavity 1111 and the second frame pressure relief cavity 1112). The volumes of the first frame pressure relief cavity 1111 and the second frame pressure relief cavity 1112 can be designed to be the same or different according to requirements.

[0051] The first pressure relief chamber 131 is connected to the first frame pressure relief chamber 1111 through the first connecting hole 112, and the second pressure relief chamber 132 is connected to the second frame pressure relief chamber 1112 through the second connecting hole 113. Multiple first connecting holes 112 and multiple second connecting holes 113 should be provided. Each of the first frame pressure relief chamber 1111 and the second frame pressure relief chamber 1112 is equipped with a corresponding explosion-proof valve 120.

[0052] In this embodiment, by adding the partition 114, the final pressure relief paths of the upper and lower layers are completely physically isolated, eliminating any cross-influence. The first frame pressure relief chamber 1111 and the second frame pressure relief chamber 1112 serve only one battery pack layer. When thermal runaway occurs in a certain layer, the generated high-pressure gas only builds pressure in its dedicated frame pressure relief chamber 111 (one of the first frame pressure relief chamber 1111 and the second frame pressure relief chamber 1112), and quickly pushes open the corresponding enclosure explosion-proof valve 120. For the battery pack layer that has not experienced thermal runaway, its corresponding frame pressure relief chamber 111 (the other of the first frame pressure relief chamber 1111 and the second frame pressure relief chamber 1112) is a closed, low-pressure space. The presence of the partition ensures that the high-pressure gas generated by the thermal runaway layer will not leak to the other side, thereby ensuring that all pressure can be effectively used to open the enclosure explosion-proof valve 120 of this layer.

[0053] like Figure 3 As shown, the first pressure relief chamber 131 and the second pressure relief chamber 132 can also be connected to the same frame pressure relief chamber 111, that is, the first connecting hole 112 and the second connecting hole 113 are both connected to the frame pressure relief chamber 111. In other words, the frame pressure relief chamber 111 is not divided into two pressure relief chambers by a partition. When a single cell in either of the upper or lower battery packs experiences thermal runaway, pressure can be directly relieved through the frame pressure relief chamber 111. Since the frame pressure relief chamber 111 is not divided into two independent small pressure relief chambers, it has a larger pressure relief space. In the event of thermal runaway of a single cell, the larger pressure relief space is more conducive to venting.

[0054] In a specific embodiment of this application, the total opening area of ​​the first connecting hole 112 and the second connecting hole 113 is greater than the exhaust area of ​​the explosion-proof valve 120 after it bursts open. It should be noted that the total opening area of ​​the first connecting hole 112 and the second connecting hole 113 refers to the sum of the opening areas of all the first connecting holes 112 and the second connecting holes 113; the exhaust area of ​​the explosion-proof valve 120 after it bursts open refers to the sum of the exhaust areas of all the explosion-proof valves 120 after they burst open.

[0055] The opening pressure and opening speed of the explosion-proof valve 120 are precisely calculated and are part of the active safety design. By ensuring that the total opening area of ​​the first connecting hole 112 and the second connecting hole 113 is greater than the total opening area of ​​the explosion-proof valve 120, it can be ensured that thermal runaway gas encounters almost no resistance before reaching the explosion-proof valve 120. The pressure relief rate and opening characteristics are entirely determined by the performance of the explosion-proof valve 120, making pressure relief predictable. The sufficiently large total area of ​​the through holes (the total opening area of ​​the first connecting hole 112 and the second connecting hole 113) allows high-temperature and high-pressure gas to flow very smoothly from the first pressure relief chamber 131 and the second pressure relief chamber 132 into the frame pressure relief chamber 111 with low flow resistance.

[0056] The total opening area of ​​the first connecting hole 112 and the second connecting hole 113 is larger than the exhaust area of ​​the explosion-proof valve 120 after it bursts. This ensures that the thermal runaway gas can be transmitted to the explosion-proof valve 120 without obstruction, allowing it to quickly reach the opening pressure and activate. This allows for the rapid discharge of high-temperature substances from the enclosure, preventing pressure buildup in the pressure relief body 130 and significantly reducing the risk of enclosure deformation or internal structural damage due to excessive pressure.

[0057] Thermal runaway eruptions can contain not only gases but also molten particles or flames. A sufficiently large orifice area means that even if a small amount of particulate matter partially blocks some orifices, the remaining total orifice area may still be larger than the exhaust area of ​​the explosion-proof valve 120 after it bursts, allowing the system to still effectively depressurize.

[0058] In a specific embodiment of this application, the box frame 110 is a rectangular structure formed by long side frames and short side frames, that is, the box frame 110 includes two parallel long side frames and two parallel short side frames.

[0059] The frame pressure relief cavity 111 is provided on at least one long side frame of the housing frame 110. That is, the frame pressure relief cavity 111 can be provided on one of the long side frames, or the frame pressure relief cavity 111 can be provided on both long side frames.

[0060] For rectangular battery packs, the distance from the center to the long side frame is typically shorter than the distance to the short side frame. In this embodiment, the pressure relief chamber 111 is located on the long side frame, meaning that the high-pressure gas generated by thermal runaway can reach the explosion-proof valve 120 of the enclosure with a shorter path and less resistance, which helps to quickly reduce the pressure inside the enclosure.

[0061] Furthermore, the plurality of first connecting holes 112 and the plurality of second connecting holes 113 are arranged along a second direction, which is the length direction of the large surface of the long side frame and is perpendicular to the first direction. The long side of the long side frame has a larger size, so arranging the plurality of first connecting holes 112 and the plurality of second connecting holes 113 at intervals along the second direction provides a larger arrangement space.

[0062] The number of first connecting holes 112 and second connecting holes 113 can be the same, or they can be designed differently according to requirements. The first connecting holes 112 and second connecting holes 113 are arranged correspondingly along the first direction, that is, in the first direction, each first connecting hole 112 is correspondingly arranged with one second connecting hole 113, and the two are aligned along the first direction. Of course, the first connecting holes 112 and second connecting holes 113 can also be staggered along the first direction. This embodiment does not limit the layout position of the first connecting holes 112 and second connecting holes 113.

[0063] In one specific embodiment of this application, there are multiple explosion-proof valves 120 for the enclosure, and these multiple explosion-proof valves 120 can be located at one end of the long side frame along the second direction. Concentrating multiple explosion-proof valves 120 at one end of the long side frame makes the leakage risk relatively concentrated and easier to control. Furthermore, it can direct the emission of all hazardous substances in a predetermined, safest direction. For example, the pressure relief port of the explosion-proof valve 120 can be directed towards the front of the vehicle or towards a specific, safe area without critical components, requiring only protection in one direction.

[0064] In another embodiment of this application, some of the explosion-proof valves 120 of the enclosure can be arranged along the second direction at one end of the long side frame, and the other part of the explosion-proof valves 120 of the enclosure can be arranged along the second direction at the other end of the long side frame. Regardless of where thermal runaway occurs in the battery pack, the distance for high-pressure gas to reach the nearest explosion-proof valve 120 is the shortest. This enables rapid and balanced pressure release, preventing deformation or tearing of the enclosure due to excessive pressure buildup at the other end of the battery pack. Even in extreme cases, if one end of the explosion-proof valve 120 fails to open properly due to blockage or damage, the other end of the explosion-proof valve 120 can still be activated to release pressure, greatly improving the reliability of the system. Due to the wide distribution of pressure relief points, the short internal gas flow path, and the relatively low overall flow velocity, the possibility of secondary risks caused by high-temperature particles splashing inside the enclosure due to high-speed airflow is reduced.

[0065] like Figure 6 and Figure 7 As shown, the pressure relief body 130 includes a first support plate 134 and a second support plate 135 arranged parallel to each other and spaced apart along a first direction, and a heat insulation plate 133 disposed between the first support plate 134 and the second support plate 135. A first pressure relief cavity 131 is formed between the first support plate 134 and the heat insulation plate 133, and a second pressure relief cavity 132 is formed between the second support plate 135 and the heat insulation plate 133; the end of the first single cell equipped with a battery explosion-proof valve is fixed to the first support plate 134, and the end of the second single cell equipped with a battery explosion-proof valve is fixed to the second support plate 135.

[0066] It should be noted that the pressure relief body 130 is a profile structure. In addition to the first support plate 134, the second support plate 135 and the heat insulation plate 133, it may also have side plates around the four edges of the first support plate 134 and the second support plate 135. A first side plate hole 1311 communicating with the first pressure relief cavity 131 and a second side plate hole 1321 communicating with the second pressure relief cavity 132 are opened on one of the side plates.

[0067] Correspondingly, a first side panel hole corresponding to the first side panel hole 1311 and a second side panel hole corresponding to the second side panel hole 1321 are opened on the corresponding side panel of the housing frame 110. The first side panel hole 1311 and the first side panel hole are connected to form a first connecting hole 112; the second side panel hole 1321 and the second side panel hole are connected to form a second connecting hole 113.

[0068] Furthermore, a first reinforcing rib 136 is provided in the first pressure relief chamber 131, and the first reinforcing rib 136 is connected to the first support plate 134 and the heat insulation plate 133 respectively. Correspondingly, a second reinforcing rib 137 is provided in the second pressure relief chamber 132, and the second reinforcing rib 137 is connected to the second support plate 135 and the heat insulation plate 133 respectively.

[0069] Thermal runaway of a single cell is a violent energy release process that instantly generates extremely high pressure inside the first pressure relief chamber 131 and the second pressure relief chamber 132. The first reinforcing rib 136 and the second reinforcing rib 137 are equivalent to adding tie rods between the heat insulation plate 133 and the first support plate 134 and the second support plate 135, which can greatly enhance the rigidity and bending strength of the heat insulation plate 133 and prevent the heat insulation plate 133 from bending, bulging or permanently deforming under the impact of high-pressure gas.

[0070] The core function of the heat insulation panel 133 is to insulate heat and separate the upper and lower cavities. If the heat insulation panel 133 is deformed or even torn due to impact, the upper and lower first pressure relief cavities 131 and second pressure relief cavities 132 will become interconnected, and the entire isolation design will fail. The first reinforcing rib 136 and the second reinforcing rib 137 ensure the structural stability of the heat insulation panel 133, thereby ensuring that it can still perform its isolation function under the worst working conditions.

[0071] Battery packs are subjected to various vibrations and shocks during vehicle use. A more robust pressure relief body 130 can reduce the risk of fatigue damage caused by vibration, while also helping to protect the battery pack mounted on the pressure relief body 130.

[0072] Furthermore, the first reinforcing rib 136 needs to avoid the first pressure relief part 1341 to prevent the first reinforcing rib 136 from obstructing the pressure relief; correspondingly, the second reinforcing rib 137 needs to avoid the second pressure relief part 1351 to prevent the second reinforcing rib 137 from obstructing the pressure relief.

[0073] In one specific embodiment of this application, the side of the heat insulation plate 133 facing the first pressure relief chamber 131 may be provided with a heat insulation coating 1331; correspondingly, the side of the heat insulation plate 133 facing the second pressure relief chamber 132 may also be provided with a heat insulation coating 1331.

[0074] Thermal runaway in a single battery cell is not only caused by high-temperature gases, but is often accompanied by the direct ejection of high-temperature flames. While the substrate of the heat insulation plate 133 (usually aluminum or steel) has heat insulation properties, its temperature rises rapidly under continuous flame. The heat insulation coating 1331 (which can be made of ceramic coating, thermally conductive adhesive, etc.) effectively blocks the direct transfer of flames and extremely high-temperature heat to the heat insulation plate 133, preventing it from melting, deforming, or experiencing a decline in mechanical properties due to overheating, thus ensuring its structural integrity.

[0075] The core function of the heat shield 133 is heat insulation. Adding the heat shield coating 1331 is equivalent to adding an active thermal barrier to the existing structural heat insulation, reducing the rate of heat transfer and the total amount of heat from the thermal runaway side to the safe side. In the event of thermal runaway, it can block heat from the dangerous side outside the heat shield 133 for a longer period. This provides the battery management system with more valuable time for fault diagnosis, early warning, and occupant escape, and significantly reduces the possibility of heat transfer to the other battery pack, triggering a secondary thermal runaway.

[0076] Metallic materials experience a sharp decrease in strength at high temperatures. If the insulation plate 133 itself is too hot, even with reinforcing ribs (first reinforcing rib 136 and second reinforcing rib 137), it may still creep or bulge under internal pressure. The insulation coating 1331 maintains the core temperature of the insulation plate 133 at a low level, ensuring that it can maintain its shape under high pressure impact and keeping the pressure relief channel unobstructed.

[0077] When a single battery cell experiences thermal runaway, the gas ejected from the battery's explosion-proof valve is not only high-temperature gas, but often also open flames reaching thousands of degrees Celsius. This high-temperature gas can easily cause a chain reaction of thermal runaway in the surrounding single batteries.

[0078] To ensure that in the event of thermal runaway in a single battery cell, the ejected flammable material does not cause thermal runaway in nearby battery cells, such as... Figure 2 As shown, in this embodiment, mica sheets 140 are provided on both sides of the pressure relief body 130 along the first direction, that is, mica sheets 140 are provided between the pressure relief body 130 and the first battery pack 200 and the second battery pack 300.

[0079] The mica sheet 140 has a thinned area at the location of the battery explosion-proof valve for each individual cell. This thinned area, being more fragile, is more easily broken in the event of thermal runaway of that individual cell, preventing the entire mica sheet 140 from being lifted. Alternatively, grooves can be made on the mica sheet 140 between adjacent individual cells, dividing it into multiple sheets corresponding to each individual cell. When one individual cell experiences thermal runaway, the mica sheet 140 will break at the groove, lifting only the sheet corresponding to that cell, while the sheets corresponding to other cells remain covered, thus preventing thermal runaway in other individual cells.

[0080] As illustrated in this application, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements. An element defined by the phrase "comprising an..." does not exclude the presence of other identical elements in the process, method, product, or apparatus that includes the element.

[0081] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0082] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0083] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this application. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A battery pack, characterized in that, It includes a battery housing (100) and a battery pack, wherein the battery housing (100) includes a housing frame (110) and a pressure relief body (130). The cavity enclosed by the box frame (110) includes at least a battery cavity for accommodating the battery pack. The pressure relief body (130) is disposed in the battery cavity to divide the battery cavity into a first battery cavity and a second battery cavity along a first direction. The pressure relief body (130) includes a first pressure relief chamber (131) and a second pressure relief chamber (132) separated by a heat insulation plate (133). The first battery chamber is provided with a first battery pack (200), and the second battery chamber is provided with a second battery pack (300). The battery explosion-proof valves of the individual cells of the first battery pack (200) and the second battery pack (300) are all facing the pressure relief body (130). The first pressure relief chamber (131) and the second pressure relief chamber (132) are provided with pressure relief parts for the passage of heat runaway gas at positions corresponding to the battery explosion-proof valves of the individual cells. The first pressure relief chamber (131) is the pressure relief channel of the first battery pack (200), and the second pressure relief chamber (132) is the pressure relief channel of the second battery pack (300). At least one side of the enclosure frame (110) is provided with a frame pressure relief cavity (111). The first pressure relief cavity (131) is connected to the frame pressure relief cavity (111) through a plurality of first connecting holes (112) arranged at intervals. The second pressure relief cavity (132) is connected to the frame pressure relief cavity (111) through a plurality of second connecting holes (113) arranged at intervals. The enclosure frame (110) is provided with an enclosure explosion-proof valve (120) that is connected to the frame pressure relief cavity (111).

2. The battery pack as described in claim 1, characterized in that, A partition (114) is provided inside the frame pressure relief cavity (111), and the partition (114) divides the frame pressure relief cavity (111) into a first frame pressure relief cavity (1111) and a second frame pressure relief cavity (1112) along the first direction. The first pressure relief chamber (131) is connected to the first frame pressure relief chamber (1111) through the first connecting hole (112), and the second pressure relief chamber (132) is connected to the second frame pressure relief chamber (1112) through the second connecting hole (113); The first frame pressure relief chamber (1111) and the second frame pressure relief chamber (1112) are respectively provided with the explosion-proof valve (120) of the box body.

3. The battery pack as described in claim 1, characterized in that, The first pressure relief chamber (131) is connected to the frame pressure relief chamber (111) through the first connecting hole (112), and the second pressure relief chamber (132) is connected to the frame pressure relief chamber (111) through the second connecting hole (113).

4. The battery pack as described in claim 1, characterized in that, The total opening area of ​​the first connecting hole (112) and the second connecting hole (113) is greater than the exhaust area of ​​the explosion-proof valve (120) after it bursts open.

5. The battery pack as described in claim 1, characterized in that, The box frame (110) is a rectangular structure formed by a long side frame and a short side frame, and the frame pressure relief cavity (111) is disposed on at least one of the long side frames of the box frame (110).

6. The battery pack as described in claim 5, characterized in that, The plurality of first connecting holes (112) and the plurality of second connecting holes (113) are arranged along a second direction, which is the length direction of the large surface of the long side frame and is perpendicular to the first direction.

7. The battery pack as described in claim 6, characterized in that, There are multiple explosion-proof valves (120) for the enclosure, and the multiple explosion-proof valves (120) are located at one end of the long side frame along the second direction.

8. The battery pack as described in claim 6, characterized in that, There are multiple explosion-proof valves (120) for the enclosure, some of which are located at one end of the long side frame along the second direction, and other parts of which are located at the other end of the long side frame along the second direction.

9. The battery pack as claimed in claim 1, characterized in that, The pressure relief body (130) includes a first support plate (134) and a second support plate (135) arranged in parallel and spaced apart along the first direction, and the heat insulation plate (133) is disposed between the first support plate (134) and the second support plate (135); The first pressure relief cavity (131) is formed between the first support plate (134) and the heat insulation plate (133), and the second pressure relief cavity (132) is formed between the second support plate (135) and the heat insulation plate (133). The end of the individual battery cell of the first battery pack (200) with a battery explosion-proof valve is fixed to the first support plate (134), and the end of the individual battery cell of the second battery pack (300) with a battery explosion-proof valve is fixed to the second support plate (135).

10. The battery pack as claimed in claim 9, characterized in that, The first pressure relief chamber (131) is provided with a first reinforcing rib (136), and the first reinforcing rib (136) is connected to the first support plate (134) and the heat insulation plate (133) respectively; And / or, The second pressure relief chamber (132) is provided with a second reinforcing rib (137), which is connected to the second support plate (135) and the heat insulation plate (133) respectively.

11. The battery pack as claimed in claim 10, characterized in that, The first pressure relief chamber (131) has a pressure relief part (1341), the second pressure relief chamber (132) has a pressure relief part (1351), the first reinforcing rib (136) avoids the first pressure relief part (1341), and the second reinforcing rib (137) avoids the second pressure relief part (1351).

12. The battery pack according to any one of claims 1-11, characterized in that, The heat insulation plate (133) has a heat insulation coating (1331) on the side facing the first pressure relief chamber (131). And / or, The heat insulation plate (133) has a heat insulation coating (1331) on the side facing the second pressure relief chamber (132).

13. The battery pack according to any one of claims 1-11, characterized in that, The pressure relief body (130) has mica sheets (140) on both sides along the first direction.

14. The battery pack according to any one of claims 1-11, characterized in that, The battery pack is a cylindrical battery pack.

Images