Battery box, battery pack and electric device

Abstract

The battery box comprises an upper cover and a lower box body, the lower box body comprises two oppositely arranged first side beams and a second side beam, the second side beam is located between the two first side beams and is connected with the end portions of the first side beams; the second side beam comprises a first portion and a second portion, the first portion is connected with the upper cover, and the second portion is located on the side of the first portion away from the upper cover; the second portion has a thinning area, and the thinning area is located on the outer side of the lower box body. Both the sealing performance of the connection between the second side beam and the upper cover can be ensured, and the overall size of the battery box can be reduced as much as possible, so that the energy density of the battery pack is not greatly affected.

Description

Technical Field

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

[0002] Battery packs, used for storing and providing electrical energy, are widely used in various devices. With technological advancements, increasingly stringent requirements are being placed on battery pack performance, including size, capacity, energy density, and safety. However, these parameters may be mutually restrictive. For example, improving battery pack safety may necessitate reducing its size; conversely, reducing battery pack size may reduce its capacity. Utility Model Content

[0003] In view of this, the present disclosure provides a battery housing, a battery pack, and an electrical device, which aims to at least improve the problem that improving the safety performance of the battery pack will simultaneously lead to an increase in the size of the battery pack.

[0004] In a first aspect, this disclosure provides a battery housing, which includes an upper cover and a lower housing. The lower housing includes two opposing first side beams and a second side beam, the second side beam being located between the two first side beams and connected to the ends of the first side beams. The second side beam includes a first portion and a second portion, the first portion being connected to the upper cover, and the second portion being located on the side of the first portion away from the upper cover. The second portion has a thinned area, and the thinned area is located on the outside of the lower housing.

[0005] Secondly, this disclosure also provides a battery pack, which includes a plurality of battery cells and a battery housing as described above, wherein the plurality of battery cells are arranged in the battery housing.

[0006] Thirdly, this disclosure also provides an electrical appliance that includes the battery pack described above.

[0007] According to the battery housing, battery pack, and electrical equipment provided in this disclosure, the portion of the second side beam furthest from the top cover is thinned. This results in a larger thickness at the connection between the second side beam and the top cover, ensuring a better seal and improving the safety of the battery pack during use. Simultaneously, the smaller thickness of the portion of the second side beam furthest from the top cover minimizes the overall size of the battery housing, ensuring that the energy density of the battery pack is not significantly affected. Attached Figure Description

[0008] It should be understood that the following figures only illustrate certain embodiments of this disclosure and should not be construed as limiting the scope.

[0009] It should be understood that the same or similar reference numerals are used in the accompanying drawings to denote the same or similar elements.

[0010] It should be understood that the accompanying drawings are only schematic, and the dimensions and scales of the elements in the drawings are not necessarily precise.

[0011] Figure 1 This is a schematic diagram of an exemplary battery box.

[0012] Figure 2 for Figure 1 The diagram shows the structure of the battery housing from one perspective.

[0013] Figure 3 for Figure 1 Enlarged view of point A in the middle.

[0014] Figure 4 for Figure 1 The diagram shows the structure of the battery box from another perspective.

[0015] Figure 5 for Figure 4 A sectional view along the CC direction.

[0016] Figure 6 for Figure 5 Enlarged view of point B in the middle.

[0017] Figure 7 This is a schematic diagram of an exemplary second side beam.

[0018] Figure 8 for Figure 7 The diagram shows the structure of the second side beam from a certain perspective.

[0019] Explanation of reference numerals in the attached drawings: 10, top cover; 11, main body; 12, bending part; 13, transition part; 20, lower housing; 201, electrical compartment; 202, battery compartment; 21, first side beam; 22, second side beam; 221, first part; 222, second part; 223, connecting part; 23, partition beam; 30, fastener. Detailed Implementation

[0020] Numerous specific details are set forth below to provide an understanding of the structure, function, and use of the embodiments described and illustrated in the specification and figures. It is to be understood that the embodiments described and illustrated herein are non-limiting examples, and thus it will be appreciated that the particular structural and functional details disclosed herein are representative and exemplary. Variations and changes may be made to these embodiments without departing from the scope of the claims.

[0021] In related technologies, the battery housing includes an upper cover and a lower housing, which are connected to form a receiving space to house multiple battery cells, forming a battery pack. Considering the safety performance during battery pack use, the connection between the upper cover and the lower housing needs to be sealed to meet certain sealing requirements, preventing moisture and dust from entering the battery housing. To meet these sealing requirements, the thickness of the lower housing's side beams is typically increased to ensure a larger contact surface at the connection point and better sealing. However, as the thickness of the battery housing's side beams increases, the overall size of the battery housing also increases. Consequently, the overall size of the battery pack also increases, and the energy density of the battery pack is significantly reduced due to the increased size of the battery housing.

[0022] The inventors discovered that the cause of the above problems was that the thickness of the side beams of the battery box was increased in order to ensure the sealing performance between the top cover and the lower box.

[0023] To address the aforementioned issues, the inventors made numerous attempts and ultimately creatively proposed the following technical solution: thinning the portion of the second side beam furthest from the top cover. This results in a larger thickness at the connection between the second side beam and the top cover, ensuring a tighter seal and improving the safety of the battery pack during use. Simultaneously, the smaller thickness of the portion of the second side beam furthest from the top cover minimizes the overall size of the battery pack, ensuring that the energy density of the battery pack is not significantly affected.

[0024] <Example Battery Housing>

[0025] This disclosure provides a battery housing, which includes an upper cover 10 and a lower housing 20. The lower housing 20 includes two opposing first side beams 21 and a second side beam 22. The second side beam 22 is located between the two first side beams 21 and connected to the ends of the first side beams 21. The second side beam 22 includes a first portion 221 and a second portion 222. The first portion 221 is connected to the upper cover 10, and the second portion 222 is located on the side of the first portion 221 away from the upper cover 10. The second portion 222 has a thinned area, and the thinned area is located on the outside of the lower housing 20.

[0026] For ease of understanding, the battery housing will be described in detail below with reference to the accompanying drawings. In the drawings, the direction shown by the X-axis can be defined, for example, as the length direction of the battery housing, i.e., the length direction of the first side beam; the direction shown by the Y-axis can be defined, for example, as the width direction of the battery housing; and the direction shown by the Z-axis can be defined, for example, as the height direction of the battery housing.

[0027] See Figures 1 to 6The battery housing includes an upper cover 10 and a lower housing 20. It can be understood that both the upper cover 10 and the lower housing 20 are hollow structures with one open end. The open end of the upper cover 10 and the open end of the lower housing 20 can be connected to each other to form a closed receiving cavity. Multiple battery cells can be located in this receiving cavity to form a battery pack.

[0028] like Figure 2 As shown, the upper cover 10 can be an integral structure obtained through processes such as die casting or injection molding. The lower housing 20 can include, for example, two opposing first side beams 21 and a second side beam 22 and a third side beam (not shown) located between the two and perpendicular to the two first side beams 21. The second side beam 22 and the third side beam are also opposing, and the two opposing first side beams 21, second side beam 22 and third side beam are connected in sequence to form the frame of the lower housing 20. Then, one end opening of the frame is closed by a bottom plate, thereby forming a lower housing 20 with an open end. To achieve the connection between the upper cover 10 and the lower housing 20, the ends of the first side beams 21, second side beam 22 and third side beams facing the upper cover 10 can be connected to the upper cover 10.

[0029] The first side beam 21, the second side beam 22, and the third side beam can be made of various materials such as aluminum alloy, copper alloy, steel, and plastic. The frame formed by the three beams can be rectangular, circular, polygonal, etc., without specific limitations. The interior of the frame can be a solid structure or contain cavities.

[0030] The explanation will take the second side beam 22 as an example: (See details in [link to documentation]). Figure 7 and Figure 8 Along the height direction of the battery box, the second side beam 22 is divided into a first part 221 and a second part 222. The first part 221 is located above the second part 222, meaning it is closer to the top cover 10. The surface of the second part 222 on the outside of the receiving cavity has a thinner area compared to the surface of the first part 221 on the outside of the receiving cavity. Therefore, along the length direction of the battery box, the size of the corresponding area of ​​the second part 222 is smaller than the size of the corresponding area of ​​the first part 221.

[0031] When the second side beam 22 connects to the top cover 10 via the side of the first part 221 facing the top cover, for example, the upper end face of the first part 221, the first part 221 has a relatively large width, ensuring a sufficiently large contact area between its upper end face and the top cover 10 to meet the sealing requirements of the battery box. Furthermore, since the second part 222 has a thinner area compared to the first part 221, the size of the battery box does not increase excessively due to the higher sealing requirements, thus not adversely affecting the energy density of the battery pack. In this way, the sealing performance of the battery box is guaranteed, ensuring the safety of the battery pack during use; at the same time, the sealing performance is maintained without increasing the size of the battery box, thus not adversely affecting the energy density of the battery pack.

[0032] like Figure 5 As shown, the battery housing may include, for example, multiple partition beams 23. These partition beams 23 may be spaced apart along the length of the battery housing to divide the housing into multiple housing units. These housing units may include, for example, a battery compartment 202 and an electrical compartment 201. Multiple battery cells may be arranged within the battery compartment 202, while the electrical compartment 201 can be used to house electrical connectors such as a BMS for controlling the multiple battery cells and connecting to external circuits. The second side beam 22 may be located near the electrical compartment 201. Electrical connectors within the electrical compartment 201 for connecting to external circuits may extend through the second portion 222 to the outside of the battery housing. This shortens the size of the electrical connectors, improving the insertion and removal space between the connectors and external circuits. Furthermore, the electrical connectors extending from the second portion 222 provide sufficient installation space for fasteners used to secure the connectors to the second portion 222, facilitating operation.

[0033] Preferably, the inner surfaces of the first part 221 and the second part 222 are coplanar; the inner surface of the first part 221 is the surface of the first part 221 located inside the lower housing 20, and the inner surface of the second part 222 is the surface of the second part 222 located inside the lower housing 20; in the length direction parallel to the first side beam 21, the thickness of the first part 221 is d1 in mm, and the thickness of the second part 222 is d2 in mm, where d1 > d2.

[0034] The first part 221 and the second part 222 are coplanar on one side of the receiving cavity. This means that the surface of the first part 221 facing the receiving cavity and the surface of the second part 222 facing the receiving cavity are on the same plane. Therefore, when the thickness d1 of the first part 221 is set to be greater than the thickness d2 of the second part 222, a thinning area will exist on the outer surface of the second part 222, reducing the length of the battery pack and thus improving its energy density.

[0035] Preferably, the value of d1 is in the range of 25mm to 30mm. A d1 within this range ensures a large contact area at the connection point between the first part 221 and the upper cover 10, thus guaranteeing the sealing performance of the battery housing. Simultaneously, the thickness of the first part 221 within this range will not be excessive, to avoid the battery housing becoming too large and negatively impacting the energy density of the battery pack.

[0036] Preferably, the value of d2 is in the range of 15mm to 20mm. A d2 within this range ensures that the second part 222 has a smaller thickness, effectively reducing the size of the battery housing and enabling the battery pack to have a larger energy density. Simultaneously, the second part within this thickness range also possesses sufficient strength to meet the strength requirements of the lower housing 20.

[0037] like Figure 7 and Figure 8 As shown, in one optional embodiment, a connecting portion 223 is provided between the first portion 221 and the second portion 222. Along the length direction parallel to the first side beam 21, the thickness of the connecting portion 223 gradually decreases from the side closer to the first portion 221 to the side closer to the second portion 222. The connecting portion 223 allows for a gradual transition from the first portion 221 to the second portion 222, thus preventing abrupt changes in thickness between them. This avoids stress concentration at the connection point of the first portion 221 and the second portion 222. Simultaneously, it also prevents sharp edges at the connection point, improving the safety of the battery casing during assembly and processing.

[0038] In one alternative embodiment, the top cover 10 includes a main body 11 and a bent portion 12. The bent portion 12 is located at the periphery of the main body 11, and a transition portion 13 is provided between the bent portion 12 and the main body 11. The first portion 221 is connected to the bent portion 12 by a fastener 30.

[0039] like Figures 4 to 6As shown, the upper cover 10 includes a main body 11, a bent portion 12, and a transition portion 13. The bent portion 12 is located at the periphery of the main body 11 and extends a certain distance away from the main body 11, so that the bent portion 12 has a certain width to achieve the connection between the bent portion 12 and the lower housing 20. Taking the connection between the bent portion 12 and the second side beam 22 as an example, the following description is provided. Figure 6 As shown, the bent portion 12 is made parallel to the upper end face of the first portion 221 of the second side beam 22, and the fastener 30 is made to pass perpendicularly through the bent portion 12 and enter the interior of the first portion 221. Thus, the connection between the bent portion 12 and the second side beam 22 is achieved by the fastener 30. The fastener 30 can be, for example, a bolt, etc., and this application does not specifically limit its application.

[0040] See also Figure 6 A transition portion 13 is provided between the main body 11 and the bent portion 12. This transition portion 13 can be configured as a smooth transition structure, such as an arc shape. The transition portion 13 configured in this way can not only reduce the stress concentration between the main body 11 and the bent portion 12 and prevent warping when the bent portion 12 is connected to the lower casing 20, but also prevent the connection between the main body 11 and the bent portion 12 from being too sharp, thus avoiding scratching the battery cells during the assembly of the battery casing and the battery cells.

[0041] See also Figure 6 As an optional implementation, the first portion 221 has a first orthographic projection on the plane where the bent portion 12 is located, and the transition portion 13 has a second orthographic projection on the plane where the bent portion 12 is located, and the first and second orthographic projections do not overlap. That is, when the bent portion 12 is connected to the first portion 221, the transition portion 13 is located outside the contact surface between the bent portion 12 and the first portion 221. In this case, in the length direction parallel to the first side beam 21, the distance between the inner surface of the second side beam 22 and the fastener 30 is L1, in mm, where 13.75mm≤L1≤16.75mm.

[0042] As described above, the inner surface of the second side beam 22 can be understood, for example, as the surface of the second side beam 22 facing the electrical compartment 201. The distance L1 between the inner surface of the second side beam 22 and the fastener 30 can be understood, for example, as the distance between the inner surface of the first part 221 and the central axis of the fastener 30. L1 satisfying the above range ensures a sufficiently large contact surface between the bent portion 12 and the first part 221, ensuring good sealing performance between the top cover 10 and the second side beam 22, preventing moisture or dust from the external environment from entering the battery box. Simultaneously, L1 satisfying the above range ensures that the contact surface between the bent portion 12 and the first part 221 is not excessively large, avoiding a decrease in battery pack energy density due to an excessively large battery box.

[0043] Optionally, L1 can be 14mm, 14.5mm, 15mm, or 16mm, etc. During use, the value of L1 can be adjusted adaptively according to factors such as the sealing requirements and dimensions of the battery housing, and is not limited to the values ​​listed above.

[0044] Alternatively, the first portion 221 has a first orthographic projection on the plane where the bend 12 is located, and the transition portion 13 has a second orthographic projection on the plane where the bend 12 is located, with the first and second orthographic projections having an overlapping area. That is, when the bend 12 is connected to the first portion 221, the transition portion 13 is located within the contact surface between the bend 12 and the first portion 221.

[0045] In this situation, due to the shape limitations of the transition portion 13, not the entire contact area between the bent portion 12 and the first portion 221 can provide a sealing effect. Therefore, in the length direction parallel to the first side beam 21, the distance between the connection point of the transition portion 13 and the bent portion 12 and the fastener 30 is L2, in mm, where 13.75mm ≤ L2 ≤ 20.75mm. For example, if the transition portion 13 is arc-shaped, the connection point between the transition portion 13 and the bent portion 12 can be understood as the tangent point between them. Only when L2 meets this range can it be ensured that the contact area between the bent portion 12 and the first portion 221 has a sufficiently large area to provide a sealing effect, ensuring good sealing performance between the top cover 10 and the second side beam 22, and preventing moisture or dust from the external environment from entering the battery pack. Simultaneously, L2 meeting the above range ensures that the contact area between the bent portion 12 and the first portion 221 is not too large, avoiding a decrease in battery pack energy density due to an excessively large battery pack.

[0046] Optionally, the value of L2 can be 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, or 20mm, etc. In use, the value of L2 can be adaptively adjusted according to factors such as the sealing requirements of the battery box and the size of the battery box, and is not limited to the values ​​listed above.

[0047] Furthermore, a buffer is provided between the first part 221 and the bent part 12. This buffer can be a gasket made of materials such as rubber, polytetrafluoroethylene, or asbestos, or it can be a sealant, to further improve the sealing and energy absorption between the first part 221 and the bent part 12. It should be noted that the size of this buffer should be less than or equal to the size of the contact surface between the first part 221 and the bent part 12 to avoid additionally increasing the size of the battery casing.

[0048] In one alternative embodiment, the end of the first side beam 21 protrudes from the surface of the second portion 222 away from the electrical compartment 201, and the edge of the second side beam 22 facing the first side beam 21 is welded to the first side beam 21.

[0049] See also Figure 1 and Figure 3 One end of the first side beam 21, near the second side beam 22, protrudes from the surface of the second part 222 that faces away from the electrical compartment 201 (i.e., the second part 222 is located on the surface outside the electrical compartment 201). Thus, the two edges of the second side beam 22, which are arranged opposite each other in the width direction of the battery box, contact the end of the first side beam 21, and the connection between the first side beam 21 and the second side beam 22 is achieved by welding.

[0050] One end of the first side beam 21, near the second side beam 22, protrudes from the surface of the second part 222 opposite to the electrical compartment 201. When the second side beam 22 is welded to the first side beam 21, the welding area between the corresponding edge of the second part 222 and the first side beam 21 can be increased, thereby appropriately increasing the width of the weld. This not only facilitates the welding operation but, more importantly, also improves the weld strength between the first side beam 21 and the second side beam 22.

[0051] See also Figure 3 As an optional implementation, in the length direction parallel to the first side beam 21, the length by which the end of the first side beam 21 protrudes beyond the surface of the second part 222 away from the electrical compartment is L3, in mm, where 5mm ≤ L3 ≤ 10mm. A L3 within this range not only ensures a sufficiently wide weld when welding the first side beam 21 and the second part 222 to guarantee the welding strength between them, but also prevents L3 from being too large, meaning the end of the first side beam 21 does not protrude too much, thus avoiding a large battery box size and negatively impacting the energy density of the battery pack.

[0052] The value of L3 can be, for example, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, or 9mm. In use, the size of L3 can be adaptively adjusted according to the welding strength requirements between the first side beam 21 and the second side beam 22, the energy density of the battery pack, and other performance requirements, and is not limited to the values ​​listed above.

[0053] In one alternative implementation, such as Figure 8As shown, the height of the second side beam 22 is H, in mm. Along the height direction of the second side beam 22, the height of the second part 222 is h, in mm, with 54% ≤ h / H ≤ 90%. The second part 222, with a height within this range, serves two purposes: firstly, its height is large enough to ensure a sufficiently long weld between the second part 222 and the first side beam 21, meeting the welding strength requirements between the first side beam 21 and the second side beam 22; secondly, the height of the second part 222 is not excessive, ensuring that the first part 221 also has sufficient height to accommodate the height of the fastener 30, thus improving the connection strength between the first part 221 and the upper cover 10.

[0054] The h / H ratio can be, for example, 60%, 65%, 68%, 70%, 72%, 75%, 80%, or 85%. In use, the h / H ratio can be adjusted adaptively according to the height of the second side beam 22, the sealing requirements of the battery box, etc., and is not limited to the ratios listed above.

[0055] The value of h ranges from 108mm to 126mm. For example, h can be 110mm, 115mm, 118mm, 120mm, 122mm, or 125mm. The value of H ranges from 140mm to 200mm. For example, H can be 150mm, 155mm, 160mm, 170mm, 180mm, or 190mm. During use, the values ​​of h and H can be adjusted adaptively according to the capacity requirements of the battery pack, and are not limited to the values ​​listed above.

[0056] In one alternative embodiment, the second part 222 has a weld between it and the first side beam 21, the weld width being L4 in mm, and 0.5 ≤ L4 / L3 ≤ 1.

[0057] The weld width L4 can be understood, for example, as the lateral distance between the two weld toes on the weld surface. A weld width within the above-mentioned proportional range ensures the weld strength between the first side beam 21 and the second side beam 22, thereby improving the stability between the first side beam 21 and the second side beam 22. At the same time, a weld width within the above range will not be too large, so as to avoid problems such as welding deformation and residual stress caused by excessive weld width when welding the first side beam 21 to the second part 222.

[0058] The L4 / L3 ratio can be, for example, 0.6, 0.65, 0.7, 0.75, 0.8, or 0.9. In use, the L4 / L3 ratio can be adjusted adaptively according to factors such as the material and thickness of the first side beam 21 and the second side beam 22, and is not limited to the ratios listed above.

[0059] The value of L4 ranges from 5mm to 8mm. For example, the value of L4 can be 5.5mm, 6mm, 6.5mm, 7mm, or 7.6mm, etc.

[0060] See also Figure 3 As an optional implementation, the edge of the end of the first side beam 21 is flush with the surface of the first portion 221 facing away from the electrical compartment 201. That is, along the length of the battery pack, the edge of the first side beam 21 near the second side beam 22 is flush with the surface of the first portion 221 facing away from the electrical compartment 201. This not only ensures that there is contact between the first side beam 21 and the first portion 221, allowing for welding, but also minimizes the length of the first side beam 21, avoiding unnecessary increases in the size of the battery pack and thus preventing any adverse impact on the energy density of the battery pack.

[0061] <Example Battery Pack>

[0062] This disclosure also provides a battery pack, which includes, for example, a battery management system (BMS), a thermal management system, an electrical connection system (high-voltage / low-voltage connectors, wiring harnesses, etc.), and a battery housing as described above. Placing these components inside the battery housing forms a complete functional unit capable of directly outputting electrical energy.

[0063] The battery enclosure may include, for example, an electrical compartment 201 and a battery compartment 202, wherein multiple battery cells are arranged in the battery compartment 202; a battery management system (BMS), a thermal management system, an electrical connection system, etc. may be installed in the electrical compartment 201.

[0064] <Example Electrical Equipment>

[0065] This disclosure also provides an electrical device including the battery pack described above. This electrical device can be, for example, a vehicle, a ship, an aircraft, a household appliance, industrial equipment, or an energy storage device. The vehicle can be, for example, a passenger car, a truck, or a construction vehicle.

[0066] It should be noted that the elements described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0067] It should be understood that multiple components and / or parts can be provided by a single integrated component or part. Alternatively, a single integrated component or part can be divided into multiple separate components and / or parts. The use of the public designation "a" or "an" to describe a component or part is not intended to exclude other components or parts.

[0068] It should be understood that although terms such as “first” or “second” may be used in this disclosure to describe various elements (such as the first side beam and the second side beam), these elements are not defined by these terms, which are only used to distinguish one element from another.

[0069] The basic principles of this disclosure have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this disclosure are merely examples and not limitations, and should not be considered as essential features of each embodiment of this disclosure. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the scope of this disclosure to the necessity of employing the aforementioned specific details for implementation.

[0070] The above are merely specific embodiments of this disclosure, but the scope of protection of this disclosure 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 disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A battery housing, characterized in that, It includes an upper cover (10) and a lower box (20). The lower box (20) includes two opposing first side beams (21) and a second side beam (22). The second side beam (22) is located between the two first side beams (21) and connected to the ends of the first side beams (21). The second side beam (22) includes a first part (221) and a second part (222), the first part (221) being connected to the upper cover (10), and the second part (222) being located on the side of the first part (221) away from the upper cover (10); The second part (222) has a thinning region, and the thinning region is located on the outside of the lower housing (20).

2. The battery housing as described in claim 1, characterized in that, The top cover (10) includes a main body (11) and a bent portion (12). The bent portion (12) is located at the periphery of the main body (11). A transition portion (13) is provided between the bent portion (12) and the main body (11). The first part (221) is connected to the bent portion (12) by a fastener (30).

3. The battery housing as described in claim 2, characterized in that, The first part (221) has a first orthographic projection on the plane where the bent part (12) is located, and the transition part (13) has a second orthographic projection on the plane where the bent part (12) is located; The first orthographic projection and the second orthographic projection do not overlap. In the length direction parallel to the first side beam (21), the distance between the inner surface of the second side beam (22) and the fastener (30) is L1, in mm, 13.75mm≤L1mm≤16.75mm. The inner surface of the second side beam (22) is the surface of the second side beam (22) located inside the lower box (20).

4. The battery housing as described in claim 2, characterized in that, The first part (221) has a first orthographic projection on the plane where the bent part (12) is located, and the transition part (13) has a second orthographic projection on the plane where the bent part (12) is located; The first orthographic projection and the second orthographic projection have an overlapping area. In the length direction parallel to the first side beam (21), the distance between the connection point of the transition part (13) and the bending part (12) and the fastener (30) is L2, in mm, 13.75mm≤L2mm≤20.75mm.

5. The battery housing as described in claim 2, characterized in that, A buffer is provided between the first part (221) and the bent part (12).

6. The battery housing as described in claim 1, characterized in that, The height of the second side beam (22) is H, in mm. In the height direction of the second side beam (22), the height of the second part (222) is h, in mm, and 54% ≤ h / H ≤ 90%.

7. The battery housing as described in claim 1, characterized in that, The inner surface of the first part (221) and the inner surface of the second part (222) are coplanar; The inner surface of the first part (221) is the surface of the first part (221) located inside the lower box (20), and the inner surface of the second part (222) is the surface of the second part (222) located inside the lower box (20); Along the length direction parallel to the first side beam (21), the thickness of the first part (221) is d1 in mm, and the thickness of the second part (222) is d2 in mm, where d1 > d2.

8. The battery housing as described in claim 7, characterized in that, A connecting portion (223) is provided between the first part (221) and the second part (222). In the length direction parallel to the first side beam (21), the thickness of the connecting portion (223) gradually decreases from the side closer to the first part (221) to the side closer to the second part (222).

9. The battery housing as described in claim 1, characterized in that, The end of the first side beam (21) protrudes from the outer surface of the second part (222), and the edge of the second side beam (22) facing the first side beam (21) is welded to the first side beam (21); The outer surface of the second part (222) is the surface of the second part (222) located outside the lower housing (20).

10. The battery housing as described in claim 9, characterized in that, In the length direction parallel to the first side beam (21), the length of the end of the first side beam (21) protruding from the outer surface of the second part (222) is L3, in mm, where 5mm≤L3mm≤10mm.

11. The battery housing as described in claim 10, characterized in that, The second part (222) has a weld between it and the first side beam (21), the weld width being L4 in mm, and 0.5≤L4 / L3≤1.

12. The battery housing as described in claim 1, characterized in that, The edge of the end of the first side beam (21) is flush with the outer surface of the first part (221); The outer surface of the first part (221) is the surface of the first part (221) located outside the lower housing (20).

13. The battery housing as described in claim 6, characterized in that, The value of h ranges from 108 mm to 126 mm.

14. The battery housing as described in claim 6, characterized in that, The value of H ranges from 140mm to 200mm.

15. The battery housing as described in claim 7, characterized in that, The value of d1 ranges from 25mm to 30mm.

16. The battery housing as described in claim 7, characterized in that, The value of d2 ranges from 15mm to 20mm.

17. The battery housing as described in claim 11, characterized in that, The value of L4 ranges from 5mm to 8mm.

18. A battery pack, characterized in that, It includes a plurality of battery cells and a battery housing as described in any one of claims 1 to 17, wherein the plurality of battery cells are arranged in the battery housing.

19. An electrical appliance, characterized in that, Includes the battery pack as described in claim 18.

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