A battery pack and an electric device

Abstract

The battery pack and the electric device are provided, the battery pack comprises: a box body, the box body comprises a frame, a bottom plate and a cover plate, the frame comprises a first beam body, the first beam body has a notch, a first cavity is arranged in the first beam body, and the first cavity is communicated to the notch; a heat exchange plate is arranged in the accommodating cavity, a battery pack is supported on the heat exchange plate, a gap space is formed between the heat exchange plate and the bottom plate, and the gap space is communicated to the notch; and a first blocking piece is arranged in the first cavity, so that gas in the gap space passes through the first cavity after entering the first cavity from the notch. Compared with the related art, the first cavity and the gap space are formed in airtight isolation by arranging the first blocking piece in the first beam body of the frame, the gas in the gap space is fundamentally blocked from reaching the electrical cabin through the notch and the first cavity, the heat diffusion rate and the risk of combustion and explosion are reduced, and the thermal safety performance and the reliability of the battery pack are significantly improved.

Description

Technical Field

[0001] This disclosure relates to the field of battery technology, and in particular to a battery pack and an electrical device. Background Technology

[0002] With the increasing demand for high-energy-density and high-safety power battery systems in new energy vehicles, the thermal management performance of battery packs has become one of the key factors restricting the safety and lifespan of the entire vehicle. To achieve the requirements of high energy density and thermal management, liquid-cooled heat exchange plates are generally integrated into the bottom of the battery pack. The heat exchange plates are laid inside the bottom plate of the battery pack, and the battery pack is directly supported on top of the heat exchange plates. There is a gap between the heat exchange plates and the bottom plate. This gap serves two purposes: firstly, it accommodates excess coolant from the pipes, wiring harnesses, and structural adhesive; secondly, it can also accommodate a buffer layer.

[0003] However, throughout the battery pack's lifespan, the aforementioned gap space will continuously accumulate flammable gases (mainly H2, CO, CH4, and carbonate vapors) from electrolyte evaporation and sealing material release. When the battery experiences thermal runaway, a large amount of high-temperature gas is instantly ejected and further enters this gap space, forming a high-pressure, high-temperature, and flammable gas storage chamber.

[0004] In related technologies, there is a notch in the frame of the battery pack, which is connected to the gap space. Gas in the gap space can be conducted through the frame to the electrical compartment of the battery pack, which brings the risk of heat diffusion and explosion. Utility Model Content

[0005] The purpose of this disclosure is to provide a battery pack and an electrical device to solve the technical problems in the related art.

[0006] In a first aspect, this disclosure provides a battery pack, comprising: The enclosure includes a frame, a bottom plate, and a cover plate. The frame has a first end and a second end. The first end of the frame is fixed to the bottom plate, and the second end of the frame is fixed to the cover plate to form an enclosure cavity for accommodating a battery pack. The frame includes a first beam with a notch. A first chamber is provided inside the first beam and the first chamber communicates with the notch. A heat exchange plate is disposed within the receiving cavity, the battery pack is supported on the heat exchange plate, a gap space is formed between the heat exchange plate and the base plate, and the gap space communicates with the notch; A first sealing element is disposed within the first chamber to restrict gas in the gap space from entering the first chamber through the gap and then passing through the first chamber.

[0007] Secondly, this disclosure provides an electrical device including the aforementioned battery pack.

[0008] Compared with related technologies, this disclosure creates an airtight barrier between the first chamber and the gap space by setting a first sealing element in the first beam of the enclosure. This fundamentally blocks the gas leakage path from the gap space to the electrical compartment via the gap and the first chamber, reducing the thermal diffusion rate and the risk of combustion and explosion, and significantly improving the thermal safety performance and reliability of the battery pack. Attached Figure Description

[0009] Figure 1 This is a perspective view of the battery pack provided in an embodiment of this disclosure.

[0010] Figure 2 yes Figure 1 The provided top view shows the battery pack with some components hidden.

[0011] Figure 3 yes Figure 1 A perspective view of the first beam of the provided battery pack in one direction.

[0012] Figure 4 yes Figure 1 A perspective view of the first beam of the provided battery pack from another direction.

[0013] Figure 5 yes Figure 1 A bottom view of the first beam of the provided battery pack.

[0014] Figure 6 yes Figure 5 A sectional view along the AA direction.

[0015] Explanation of reference numerals in the attached figures: 10-Box body, 11-Frame, 111-First beam, 112-Main body, 113-Extension, 114-Notch, 115-First chamber, 116-First opening, 117-First limiting member, 118-First bottom surface, 119-Cavity, 120-Second chamber, 121-First through hole, 122-Second through hole, 123-Second opening, 124-Second limiting member, 125-Outer box, 126-Connecting hole, 12-Bottom plate, 13-Cover plate, 14-Electrical compartment, 15-Weld mark; 20 - Heat exchange plate; 30 - First sealing component; 40 - Second sealing component; 50-Battery pack. Detailed Implementation

[0016] The embodiments of this disclosure are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this disclosure, and should not be construed as limiting this disclosure.

[0017] like Figures 1 to 6 As shown, an embodiment of this disclosure provides a battery pack, including a housing 10 and a heat exchange plate 20 and a first sealing member 30 disposed within the housing 10.

[0018] A battery pack, as a rechargeable battery, is the power source for new energy vehicles. A battery pack includes a battery pack composed of multiple battery cells connected in series and / or in parallel, a battery management system (BMS), a thermal management system, an electrical connection system (high-voltage / low-voltage connectors, wiring harnesses, etc.), structural components (shell, brackets, etc.), and protective components. All of the above components are placed inside the housing 10 and sealed by the cover plate 13 to form a complete functional unit that can directly output electrical energy.

[0019] The enclosure 10 refers to a closed or semi-closed structure made of materials such as metal and plastic. It is the physical carrier of the battery pack, and its design and manufacturing must meet the safety, reliability and functionality requirements of the battery pack in different usage scenarios.

[0020] The enclosure 10 provides installation space for the battery pack, BMS, cooling system, electrical connection components, etc., and through reasonable structural design, these components are fixed inside the enclosure 10 to ensure that they maintain a relatively stable position during battery pack operation, and to avoid damage to components or loosening of connections due to vibration, impact or other factors.

[0021] The heat exchange plate 20 is used to dissipate heat from the battery cells to regulate their temperature. A refrigerant can be stored within the heat exchange plate 20, and cooling of the battery cells is achieved through a phase change of the refrigerant. The refrigerant can be a gas, solid, or liquid.

[0022] When the refrigerant is liquid, a liquid with a high specific heat capacity, such as water, can be placed inside the liquid refrigerant as a coolant to achieve liquid cooling heat dissipation for the battery cells. The heat exchange plate 20 has liquid cooling channels, specifically, the shapes of which are varied, such as "U", "U-", or "S" shaped. Optionally, the heat exchange plate 20 also includes a liquid inlet and a liquid outlet, both of which are connected to a current collector for the inlet and outlet of the heat exchange medium. The heat exchange plate 20 can be made of a material with a certain hardness and strength (such as stainless steel). This makes the heat exchange plate 20 less prone to deformation when the battery cells are subjected to compression or impact, allowing the battery cells to have higher structural strength and improved safety performance. The heat exchange plate 20 can be made of various materials, including but not limited to: copper, iron, aluminum, stainless steel, aluminum alloy, etc. The heat exchange plate 20 can also be made of nylon, plastic, etc.

[0023] When the refrigerant is gas, the heat exchange plate 20 is located at the bottom of the housing 10, i.e., connected to the frame 11, forming a sealed housing structure. The heat exchange plate 20 can be fixed to the frame 11 using nuts or other means. In order to form an airflow cavity inside the housing 10, a gap is left between the heat exchange plate 20 and the bottom plate 12, so that the bottom plate 12, the frame 11, and the heat exchange plate 20 together form an airflow cavity.

[0024] The housing 10 includes a frame 11, a base plate 12, and a cover plate 13. The frame 11 has a first end and a second end. The first end of the frame 11 is fixed to the base plate 12, and the second end of the frame 11 is fixed to the cover plate 13 to form a receiving cavity for accommodating the battery pack 50.

[0025] The frame 11 can be made of various materials, such as aluminum alloy, copper alloy, steel, and plastic. The frame 11 can be rectangular, circular, polygonal, etc., with no specific limitation. Multiple beams together constitute the frame 11, including a first beam 111 and longitudinal beams connecting the first beam 111. The first beam 111 is a transverse beam, with its opposite ends connected to the longitudinal beams. The first beam 111 has a notch 114, forming a lateral channel for the heat exchange plate 20 to extend out of the frame 11 and connect to the liquid cooling connector. A first chamber 115 is provided inside the first beam 111, communicating with the notch 114 and extending along the length of the first beam 111. The first chamber 115 can serve as a weight-reduction hole, reducing the weight per unit length of the frame 11 to meet lightweight requirements.

[0026] The base plate 12 is the main load-bearing component of the battery pack, used to support and fix the battery pack 50, battery management system, cooling system, and other components inside the battery pack. The base plate 12 is located at the bottom of the frame 11, for example, by welding, riveting, screwing, or other methods. The base plate 12 can be made of various materials, such as high-strength materials like aluminum alloy, steel, and stainless steel. The base plate 12 can be rectangular, circular, polygonal, or a plate-like structure; its specific shape is not limited, and its size is determined by the number of batteries contained in the battery pack and the size of the batteries.

[0027] The cover plate 13 is a sealing component used to enclose the receiving cavity of the housing 10, sealing the battery pack 50 within the receiving cavity and isolating it from the outside world to prevent external moisture and dust from affecting the battery pack 50. The cover plate 13 can be made of non-metallic materials, such as resin materials used as raw materials for plastic products, such as polyphenylene sulfide resin (PPS), polyphenylene sulfide resin (PPO), polypropylene resin (PP), etc.; or it can be a composite material including reinforcing agents and resin, with commonly used reinforcing agents being glass fiber, carbon fiber, graphite fiber, etc. It can also be made of metallic materials, such as iron, aluminum, aluminum alloys, iron alloys, stainless steel, etc. The cover plate 13 can be in various shapes, such as a cuboid, depending on the specific requirements.

[0028] The heat exchange plate 20 is located within the receiving cavity, between the base plate 12 and the battery pack 50. The heat exchange plate 20 serves as a load-bearing support, supporting the battery pack 50. The heat exchange plate 20 uses liquid cooling to quickly dissipate the heat generated during charging and discharging of the battery pack 50, preventing thermal runaway. A gap space is formed between the heat exchange plate 20 and the base plate 12. This gap space serves two purposes: firstly, it accommodates excess coolant pipes, wiring harnesses, and structural adhesive; secondly, it can also accommodate a buffer layer. The gap space connects to the notch 114. Gas within the gap space can enter the first beam 111 through the notch 114, then enter other beams (such as longitudinal beams), and finally connect to the electrical compartment 14 of the battery pack, posing a risk of heat diffusion and explosion.

[0029] In the embodiments provided in this disclosure, reference is made to Figure 3 As shown, the first sealing element 30 is disposed within the first chamber 115 to achieve intracavity cutoff, thereby restricting the gas in the gap space from entering the first chamber 115 through the gap 114 and then passing through the first chamber 115 to reach other beam bodies. The first sealing element 30 is a plate structure, completely housed within the first chamber 115. The first sealing element 30 utilizes the first chamber 115 as an installation channel and is protected by the peripheral wall of the beam body to avoid failure due to bumps during assembly and transportation.

[0030] The first sealing element 30 blocks the gas entering the first beam 111 from being conducted out of the first beam 111, thus forming an airtight isolation between the first chamber 115 and the gap space. This fundamentally blocks the gas in the gap space from reaching the electrical compartment 14 through the gap 114 and the first chamber 115, reducing the thermal diffusion rate and the risk of combustion and explosion, and significantly improving the thermal safety performance and reliability of the battery pack.

[0031] Furthermore, referring to Figure 3 as well as Figure 4 As shown, along the length of the first beam 111, a first opening 116 is formed on the side wall of the first chamber 115 away from the notch 114. The first opening 116 and the notch 114 are on opposite sides along the length of the first beam 111. The first opening 116 is close to the adjacent beam (e.g., a longitudinal beam). The first sealing member 30 is disposed close to the first opening 116. The distance between the sealing surface formed by the first sealing member 30 and the end face of the first opening 116 is between 0-5mm. It can either fit against the end face of the first opening 116 or have a reserved gap between it and the end face of the first opening 116.

[0032] In related technologies, if the first sealing member 30 is installed from the side of the notch 114, the operator needs to push it in laterally from the side of the notch 114. The pushing stroke is short and the visibility is poor, and the space is relatively cramped, making assembly difficult. However, the embodiment provided in this disclosure places the first sealing member 30 on the side away from the notch 114. The first opening 116 is directly exposed on the end face of the first beam 111 along its length direction to form an open end. The first sealing member 30 is inserted through the first opening 116, which has a long stroke and good visibility. The installation and fixing tools are not interfered with by surrounding parts. At the same time, the sealing member is placed close to the first opening 116, which means that its final sealing surface is located at the end of the first chamber 115. A cavity is formed between the notch 114 and the first sealing member 30. This cavity can serve as an expansion buffer volume for ejected material in the event of battery thermal runaway, reducing the instantaneous pressure peak and reducing the risk of thermal diffusion.

[0033] In one feasible implementation, the first sealing member 30 is welded to the inner wall of the first chamber 115 to form a weld mark 15, and the circumferential outer wall surface of the first sealing member 30 is welded to the inner wall surface of the first chamber 115 to seal the first chamber 115. The high-strength connection brought about by the welding connection can make the first sealing member 30 maintain its sealing performance even under thermal runaway high pressure, reducing the diffusion of gas or heat.

[0034] Along the length of the first beam 111, the shortest distance between the weld mark 15 and the first opening 116 is less than 2mm-8mm. Specifically, the shortest distance can be 2mm, 3mm, 4mm, 5mm, 6mm, 7mm or 8mm, and can be any value between 2mm and 8mm, as listed above.

[0035] The minimum distance between the solder mark 15 and the first opening 116 cannot be too large. If the minimum distance between the solder mark 15 and the first opening 116 is too large and exceeds the preset range, the first sealing member 30 must extend into the interior of the first chamber 115. During assembly, the visibility is poor and the welding tools are difficult to reach, causing assembly difficulties.

[0036] In the embodiments provided in this disclosure, reference is made to Figure 6 As shown, the first beam 111 has a first limiting member 117 within the first chamber 115. The first limiting member 117 is used to limit the installation position of the first sealing member 30. The first limiting member 117 and the first beam 111 are preferably integrally formed. Through mechanical interference limiting, the first sealing member 30 has a unique installation position. When the first sealing member 30 is inserted, the front end of the first sealing member 30 contacts the first limiting member 117 and reaches the predetermined axial position, eliminating the error of manual pushing depth and ensuring that the distance between the weld mark 15 and the first opening 116 is within the range of less than 2mm-8mm.

[0037] In one feasible implementation, the first limiting member 117 is a limiting rib protruding from the inner wall of the first chamber 115. The limiting rib is a strip-shaped protrusion extending along the length of the first beam 111. The end of the limiting rib can contact the end face of the first sealing member 30 to restrict the first sealing member 30 from moving further inward. The limiting rib has a certain height and is symmetrically arranged. The first sealing member 30 stops when it is pushed into the limiting rib, ensuring that the distance between the weld mark 15 and the first opening 116 is within the range of less than 2mm-8mm.

[0038] The protrusion dimension of the first limiting member 117 is 1mm-10mm. Specifically, the protrusion dimension can be 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm or 10mm. The value can be one of the aforementioned values ​​or any value between 1mm and 10mm.

[0039] The protruding dimension of the first limiting member 117 cannot be too small. If it is too small, the limiting height will be insufficient, and the first sealing member 30 may easily exceed the first limiting member 117 after thermal expansion or long-term vibration, resulting in axial movement and causing the sealing position of the first limiting member 117 to shift, resulting in local gaps. The protruding dimension of the first limiting member 117 cannot be too large. If it is too large, it will encroach on the expansion buffer space of the first beam 111 as ejected material in the event of battery thermal runaway, increasing the risk of thermal diffusion, and the two opposing first limiting members 117 are prone to interference.

[0040] In the embodiments provided in this disclosure, reference is made to Figure 3 as well as Figure 4 As shown, the first beam 111 includes a main body 112 and an extension 113, which are preferably integrally formed. The main body 112 has a first bottom surface 118 on the side near the bottom plate 12, and the extension 113 is disposed on the first bottom surface 118. There are at least two extensions 113, and multiple extensions 113 are spaced apart along the length direction of the main body 112.

[0041] The extension 113 is located in the gap space between the heat exchange plate 20 and the base plate 12. The notch 114 is formed between two adjacent extensions 113. The number of notches 114 can be freely increased or decreased according to actual needs, which improves design flexibility. Both the base plate 12 and the heat exchange plate 20 have protruding parts. The protruding parts of the base plate 12 and the heat exchange plate 20 are located between the two extensions 113 and extend into the notch 114. The notch 114 is also facing the gap space.

[0042] The first chamber 115 is located inside the extension 113, which is used to form a notch 114. The main body 112 remains completely closed to bear the torsion load of the whole vehicle and the bottom ball impact load, so as to avoid forming a notch 114 in the main stress area of ​​the frame 11, thereby damaging the overall strength of the frame 11.

[0043] In the embodiments provided in this disclosure, the main body 112 is provided with a plurality of cavities 119, which form a mesh structure and extend along the length direction of the main body 112. The cavities 119 serve as weight-reduction holes, reducing the weight per unit length of the main body 112 and meeting the requirements for lightweighting. The cavities 119 can also serve as common spaces for cooling channels or wiring harness channels, and are not limited thereto.

[0044] Furthermore, referring to Figure 6As shown, the plurality of cavities 119 includes a second chamber 120, which is one of the cavities 119. The second chamber 120 is adjacent to the first chamber 115 and is located above the first chamber 115. A plurality of first through holes 121 are provided through the wall shared by the second chamber 120 and the first chamber 115. The first through holes 121 extend along the direction of gravity and are arranged at intervals along the length of the main body 112. A plurality of second through holes 122 are provided through the wall of the first chamber 115 away from the second chamber 120. The second through holes 122 also extend along the direction of gravity. The plurality of second through holes 122 and the plurality of first through holes 121 are arranged one-to-one to allow bolts to pass through sequentially. After the bolts fix the base plate 12 to the frame 11, the tail end of the bolt passes through the second through holes 122 and the first through holes 121 sequentially to achieve a fixed connection.

[0045] Along the length of the first beam 111, refer to Figure 3 , Figure 4 as well as Figure 6 As shown, a second opening 123 is formed on the side wall of the second chamber 120 away from the notch 114. The second opening 123 and the first opening 116 are located on the same side wall. Since the second chamber 120 and the first chamber 115 are connected by the first through hole 121, the gas in the gap space can also enter the second chamber 120 through the first through hole 121. To prevent gas in the second chamber 120 from being conducted out through the second opening 123 of the first beam 111, in the embodiments provided in this disclosure, the battery pack is further provided with a second sealing member 40. The second sealing member 40 is disposed in the second chamber 120 and is closer to the second opening 123 than the plurality of first through holes 121. On the one hand, this makes it easier for the second sealing member 40 to be inserted into the second opening 123 for assembly. On the other hand, the sealing surface formed by the second sealing member 40 is located between the plurality of first through holes 121 and the second opening 123. Gas overflowing into the second chamber 120 from the first through holes 121 is blocked by the second sealing member 40, fundamentally blocking the gas in the gap space from reaching the electrical compartment 14 through the notch 114, the first chamber 115, the first through holes 121 and the second chamber 120, thereby reducing the thermal diffusion rate and the risk of combustion and explosion, and significantly improving the thermal safety performance and reliability of the battery pack.

[0046] In the embodiments provided in this disclosure, the first beam 111 is provided with a second limiting member 124 within the second chamber 120. The second limiting member 124 is used to limit the installation position of the second sealing member 40. The second limiting member 124 and the first beam 111 are preferably integrally formed. Through mechanical interference limiting, the second sealing member 40 has a unique installation position. When the second sealing member 40 is inserted, the front end of the second sealing member 40 contacts the second limiting member 124 and reaches the predetermined axial position, eliminating the error of manual pushing depth.

[0047] In one feasible implementation, the second limiting member 124 is a limiting rib protruding from the inner wall of the second chamber 120. The limiting rib is a strip-shaped protrusion extending along the length direction of the first beam 111. The end of the limiting rib can contact the end face of the second sealing member 40 to restrict the second sealing member 40 from moving further inward. The limiting rib has a certain height and is symmetrically arranged. The second sealing member 40 stops when it is pushed into the limiting rib.

[0048] The protrusion dimension of the second limiting member 124 is 1mm-10mm. Specifically, the protrusion dimension can be 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm or 10mm. The value can be one of the values ​​listed above or any value between 1mm and 10mm.

[0049] The protruding dimension of the second limiting member 124 cannot be too small. If it is too small, the limiting height will be insufficient, and the second sealing member 40 may easily exceed the second limiting member 124 after thermal expansion or long-term vibration, resulting in axial movement and causing the sealing position of the second limiting member 124 to shift, resulting in local gaps. The protruding dimension of the second limiting member 124 cannot be too large. If it is too large, the two opposing second limiting members 124 are prone to interference.

[0050] In one feasible implementation, the first sealing element 30 and the second sealing element 40 are an integral structure. The common wall of the first chamber 115 and the second chamber 120 can serve as the limit for this integral sealing element. The integral sealing element can simultaneously seal the first chamber 115 and the second chamber 120. Only one assembly is needed to form an annular seal on the inner wall surface of the first chamber 115 and the second chamber 120, which speeds up the assembly cycle and eliminates the need to worry about missing either the first sealing element 30 or the second sealing element 40.

[0051] In another feasible implementation, the first sealing component 30 and the second sealing component 40 are separate structures, which can be assembled and replaced separately and are easy to maintain.

[0052] In the embodiments provided in this disclosure, the side of the first beam 111 facing away from the receiving cavity has an extension box 125. The extension box 125 is integrally formed or welded to the first beam 111. The heat exchange plate 20 extends from the notch 114 only into the extension box 125. The extension box 125 is provided with a connection hole 126. The extension box 125 is a box structure, and the connection hole 126 is disposed through the box structure. The axis of the connection hole 126 can be perpendicular to the surface of the protrusion 125. A liquid cooling connector is installed in the connection hole 126. The liquid cooling connector can be installed and fixed by means of threaded insertion, compression fitting, or quick plug-in, etc., which is not limited here. An O-ring or sealant can be added between the liquid cooling connector and the connection hole 126 to further reduce the risk of leakage.

[0053] The liquid cooling connector is connected to the heat exchange plate 20 extending into the outer casing 125. The liquid cooling connector can be connected by welding, brazing, crimping, or threaded connection, so that the flow channels of the liquid cooling connector and the heat exchange plate 20 are connected. Since the outer casing 125 extends out of the housing 10, the connection position between the liquid cooling connector and the heat exchange plate 20 is outside the housing 10, which does not encroach on the arrangement space of the battery pack 50 inside the housing 10, thereby improving the energy density of the battery pack 50.

[0054] Secondly, this disclosure provides an electrical device that includes the aforementioned battery pack.

[0055] By way of example only, electrical equipment can be, but is not limited to, vehicles, ships, aircraft, household appliances, and industrial equipment. For example, vehicles can be passenger cars, trucks, construction vehicles, etc.

[0056] In addition, electrical equipment can also be used for the storage, conversion, and release of recyclable electrical energy.

[0057] The above description, based on the embodiments shown in the figures, details the structure, features, and effects of this disclosure. The above description is only a preferred embodiment of this disclosure, but this disclosure does not limit the scope of implementation to what is shown in the figures. Any changes made in accordance with the concept of this disclosure, or modifications to equivalent embodiments with equivalent changes, that do not exceed the spirit covered by the specification and figures, should be within the protection scope of this disclosure.

Claims

1. A battery pack, characterized in that, include: The enclosure includes a frame, a bottom plate, and a cover plate. The frame has a first end and a second end. The first end of the frame is fixed to the bottom plate, and the second end of the frame is fixed to the cover plate to form an enclosure cavity for accommodating a battery pack. The frame includes a first beam with a notch. A first chamber is provided inside the first beam and the first chamber communicates with the notch. A heat exchange plate is disposed within the receiving cavity, the battery pack is supported on the heat exchange plate, a gap space is formed between the heat exchange plate and the base plate, and the gap space communicates with the notch; A first sealing element is disposed within the first chamber to restrict gas in the gap space from entering the first chamber through the gap and then passing through the first chamber.

2. The battery pack according to claim 1, characterized in that, Along the length of the first beam, a first opening is formed on the side wall of the first chamber away from the notch, and the first sealing member is disposed close to the first opening.

3. The battery pack according to claim 2, characterized in that, The first sealing component is welded to the inner wall of the first chamber to form a weld mark. In the length direction of the first beam, the shortest distance between the weld mark and the first opening is less than 2mm-8mm.

4. The battery pack according to claim 1, characterized in that, The first beam is provided with a first limiting member in the first cavity, and the first limiting member is used to limit the installation position of the first sealing member.

5. The battery pack according to claim 4, characterized in that, The first limiting member is a limiting rib protruding from the inner wall of the first chamber.

6. The battery pack according to claim 5, characterized in that, The protrusion of the first limiting member is 1mm-10mm.

7. The battery pack according to claim 1, characterized in that, The first beam includes a main body and an extension, wherein: The main body has a first bottom surface on the side near the bottom plate; The extension is provided on the first bottom surface, and there are at least two extensions. The multiple extensions are spaced apart along the length direction of the main body. The notch is formed between two adjacent extensions, and the first chamber is provided inside the extension.

8. The battery pack according to claim 7, characterized in that, The main body is provided with a plurality of cavities, which extend along the length direction of the main body.

9. The battery pack according to claim 8, characterized in that, The cavity includes a second chamber adjacent to the first chamber. A plurality of first through holes are provided through the wall shared by the second chamber and the first chamber. The first through holes are arranged at intervals along the length of the main body. A plurality of second through holes are provided through the wall of the first chamber away from the second chamber. The plurality of second through holes and the plurality of first through holes are arranged in a one-to-one correspondence to allow bolts to pass through in sequence.

10. The battery pack according to claim 9, characterized in that, Along the length of the first beam, a second opening is formed on the side wall of the second chamber away from the notch. The battery pack is also provided with a second sealing member, which is disposed in the second chamber. The second sealing member is closer to the second opening than the plurality of first through holes, so as to restrict the gas in the gap space from entering the second chamber through the first through holes and passing through the second chamber.

11. The battery pack according to claim 10, characterized in that, The first beam is provided with a second limiting member in the second cavity, and the second limiting member is used to limit the installation position of the second sealing member.

12. The battery pack according to claim 11, characterized in that, The second limiting member is a limiting rib protruding from the inner wall of the second chamber.

13. The battery pack according to claim 12, characterized in that, The protrusion of the second limiting member is 1mm-10mm.

14. The battery pack according to claim 10, characterized in that, The first sealing element and the second sealing element are an integral structure.

15. The battery pack according to claim 10, characterized in that, The first sealing component and the second sealing component are separate structures.

16. The battery pack according to claim 1, characterized in that, The first beam has an extension box on the side opposite to the receiving cavity. The heat exchange plate extends into the extension box from the notch. The extension box is provided with a connection hole. A liquid cooling connector is installed in the connection hole and connected to the heat exchange plate extending into the extension box.

17. An electrical appliance, characterized in that, Includes the battery pack as described in any one of claims 1-16.

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