Battery pack shell and battery pack

Abstract

The utility model provides a battery pack shell and a battery pack. Wherein the battery pack shell comprises a box body, the box body is provided with a box body mounting cavity, the box body mounting cavity is used for accommodating a cooling liquid to immerse a plurality of battery monomers, a liquid outlet is formed in the side part of the box body, and the liquid outlet is used for mounting a liquid outlet pipe to discharge the cooling liquid; and the liquid outlet structure is mounted at the side part of the box body, is positioned in the box body mounting cavity, and is provided with a communicating opening and a liquid outlet cavity which are communicated with each other. Wherein the box body mounting cavity is communicated with the liquid outlet through the communication opening and the liquid outlet cavity, a first horizontal plane where the communication opening is located is higher than the upper surfaces of the battery monomers and the bottom of the liquid outlet cavity, and a second horizontal plane where the bottom end of the liquid outlet is located is lower than the first horizontal plane; cooling liquid for immersing the plurality of single batteries sequentially flows into the communication opening, the liquid outlet cavity and the liquid outlet pipe from the box body mounting cavity. Therefore, when the height of the bottom end of the liquid outlet is lower than that of the upper surface of the battery monomer, the cooling liquid can also immerse the battery monomer.

Description

Technical Field

[0001] The utility model relates to the field of batteries, and particularly to a battery pack housing and a battery pack. Background Art

[0002] In a submerged battery pack, the liquid outlet of the coolant needs to be a certain distance above the upper surface of the battery module so that the coolant can completely submerge the battery module. Therefore, the position design of the liquid outlet in the battery pack housing is restricted by the height of the battery module, which is not conducive to the design of the battery pack housing. Summary of the Utility Model

[0003] An embodiment of the utility model provides a battery pack housing and a battery pack, which can solve the problem of low space utilization rate of the battery pack.

[0004] In a first aspect, an embodiment of the utility model provides a battery pack housing, which includes:

[0005] A box body is provided with a box body installation cavity for accommodating a coolant to submerge a plurality of battery cells. A liquid outlet is provided on the side of the box body for installing a liquid outlet pipe to discharge the coolant; and a liquid outlet structure is installed on the side of the box body, located in the box body installation cavity, and is provided with a communicating opening and a liquid outlet cavity that communicate with each other; wherein, the box body installation cavity communicates with the liquid outlet through the communicating opening and the liquid outlet cavity. The first horizontal plane where the communicating opening is located is higher than the upper surface of the plurality of battery cells and the bottom of the liquid outlet cavity, and the second horizontal plane where the bottom end of the liquid outlet is located is lower than the first horizontal plane, so that the coolant submerging the plurality of battery cells flows from the box body installation cavity into the communicating opening, the liquid outlet cavity, and the liquid outlet pipe in sequence.

[0006] In one embodiment, the second horizontal plane is lower than the upper surface of the plurality of battery cells.

[0007] In one embodiment, the communicating opening is provided at the top of the liquid outlet structure and communicates with the top of the liquid outlet cavity. The liquid outlet structure includes side plates that face the liquid outlet and enclose at least a part of the liquid outlet cavity. The orthographic projection of the liquid outlet on the side plates is located within the boundary of the side plates.

[0008] In one embodiment, the distance from the side of the side plate close to the liquid outlet to the side is D1, the length of the side plate is D2, and the cross-sectional area of the inner diameter of the liquid outlet pipe is S1; wherein, 2*S1 > D1*D2 > S1.

[0009] In one embodiment, the inner diameter of the liquid outlet pipe is r1; wherein, 2*r1 > D1 > r1.

[0010] In one embodiment, the outer diameter of the liquid outlet pipe is R1; wherein, R1 + 20mm > D2 > R1 + 10mm.

[0011] In one embodiment, the battery pack housing further includes a cover plate. The top of the box body is provided with a box body installation opening communicating with the box body installation cavity. The cover plate covers the box body installation opening. The distance between the cover plate and the communicating opening is D3, and the height difference between the first horizontal plane and the upper surfaces of the plurality of battery cells is H1; wherein, D3 > 5 mm and H1 > 10 mm.

[0012] In one embodiment, the width of the side plate is D4; wherein, R1 + 20 mm > D4 > R1 + 10 mm.

[0013] In one embodiment, the center of the liquid outlet is located on the center line in the width direction of the side plate.

[0014] In a second aspect, an embodiment of the present invention provides a battery pack, including the battery pack housing as in the first aspect.

[0015] The present invention provides a battery pack housing and a battery pack. The battery pack housing includes a box body and a liquid outlet structure. Among them, the box body is provided with a box body installation cavity, and a liquid outlet is opened on its side. The liquid outlet is used to install a liquid outlet pipe to discharge the coolant. The liquid outlet structure is installed on the side of the box body and is located in the box body installation cavity, and is provided with a communicating opening and a liquid outlet cavity. The box body installation cavity communicates with the liquid outlet through the communicating opening and the liquid outlet cavity in sequence. The first horizontal plane where the communicating opening is located is higher than the upper surfaces of the plurality of battery cells and higher than the second horizontal plane where the bottom end of the liquid outlet is located. When the coolant submerges the plurality of battery cells, the coolant then flows through the communicating opening, the liquid outlet cavity, and the liquid outlet pipe in sequence. Therefore, when the horizontal plane where the bottom end of the liquid outlet of the battery pack housing provided by the present invention is lower than the upper surfaces of the plurality of battery cells, it can still achieve that the coolant completely submerges the plurality of battery cells and then discharges from the liquid outlet. Therefore, the position design of the liquid outlet on the battery pack housing is no longer restricted by the height of the upper surfaces of the battery cells, which is convenient for the design of the battery pack housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those skilled in the art, without creative efforts, other drawings can be obtained according to these drawings.

[0017] Figure 1 is a schematic structural diagram of the battery pack housing provided by the embodiment of the present invention;

[0018] Figure 2 is Figure 1 a schematic structural diagram of the liquid outlet structure installed on the side of the box body in

[0019] Figure 3 is Figure 2Enlarged schematic view of part A;

[0020] Figure 4 is Figure 3 a sectional view;

[0021] Figure 5 is Figure 2 a top view structural schematic diagram;

[0022] Figure 6 is Figure 4 an enlarged schematic view of part B;

[0023] Figure 7 is Figure 2 a front view structural schematic diagram;

[0024] Figure 8 is Figure 6 an enlarged schematic view of part C.

[0025] Explanation of reference numerals:

[0026] 100, battery pack housing; 110, box body; 120, liquid outlet structure; 121, communication opening; 122, liquid outlet cavity; 123, side plate; 130, box body installation cavity; 140, liquid outlet pipe; 200, battery cell; 300, cover plate; 400, box body installation opening. Specific embodiments

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present invention. In addition, it should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention. In the present invention, unless otherwise stated, the orientation terms such as "upper" and "lower" usually refer to the upper and lower in the actual use or working state of the device, specifically the drawing direction in the accompanying drawings; and "inner" and "outer" refer to the outline of the device.

[0028] An immersion battery pack is a battery pack design in which the entire battery module or battery cell is placed in a liquid coolant to provide more effective heat dissipation. Compared with traditional air-cooled or liquid-cooled heat dissipation systems, the immersion battery pack can dissipate heat more evenly and has better thermal management performance under extreme working conditions. The immersion battery pack generally consists of a battery module, a coolant circulation system, a coolant, and a battery pack housing, etc. Several battery cells in the battery module are placed in a sealed container in the coolant to ensure that the battery is completely immersed. Among them, the coolant circulation system, usually composed of a pump, a radiator, pipes, and a control unit, is used to circulate the coolant to achieve heat dissipation. In the related art, in order to achieve the "immersion" effect, when designing the battery pack housing, it is necessary to ensure that the height of the bottom end of the liquid outlet is higher than the upper surface of the battery module by a certain distance, so that the coolant can completely immerse the battery module and then be discharged from the liquid outlet. Therefore, the position design of the liquid outlet in the battery pack housing is restricted by the height of the battery module.

[0029] To solve the problem of the limited design of the battery pack housing described above, an embodiment of the present utility model provides a battery pack housing 100. Please refer to Figure 1 、 Figure 2 and Figure 3 , Figure 1 is a schematic structural diagram of the battery pack housing 100 provided by an embodiment of the present utility model, Figure 2 is Figure 1 a schematic structural diagram of the liquid outlet structure 120 installed on the side of the box body 110 in Figure 3 is Figure 2 an enlarged schematic diagram of part A in

[0030] Among them, please refer to Figure 4 , Figure 4 is Figure 3Cross-sectional view. The housing installation cavity 130 communicates with the liquid outlet through the communication opening 121 and the liquid outlet cavity 122. The first horizontal plane where the communication opening 121 is located is higher than the upper surfaces of the plurality of battery cells 200 and the bottom of the liquid outlet cavity 122. The second horizontal plane where the bottom end of the liquid outlet is located is lower than the first horizontal plane, so that the coolant submerging the plurality of battery cells 200 flows from the housing installation cavity 130 into the communication opening 121, the liquid outlet cavity 122, and the liquid outlet pipe 140 in sequence. After the coolant in the housing installation cavity 130 submerges the plurality of battery cells 200, it is necessary to wait for the liquid level height of the coolant to gradually rise to the height of the first horizontal plane where the communication opening 121 is located, and then flow into the liquid outlet cavity 122 of the liquid outlet structure 120 from the communication opening 121, and finally flow out from the pipe orifice of the liquid outlet pipe 140 located in the liquid outlet cavity 122.

[0031] In this embodiment, even when the second horizontal plane where the bottom end of the liquid outlet is located is lower than the height of the upper surface of the battery cell 200, due to the limitation of the liquid outlet structure 120, the coolant must submerge the upper surface of the battery cell 200 before it can flow into the liquid outlet pipe 140 installed at the liquid outlet from the communication opening 121 of the liquid outlet structure 120. At the same time, the liquid outlet structure 120 occupies a small volume in the housing installation cavity 130, so the space utilization rate of the battery pack is ensured to be high, which is convenient for the installation of other components and reduces the production material cost of the battery pack housing 100.

[0032] In some embodiments, please refer to Figure 1 , the second horizontal plane where the bottom end of the liquid outlet is located is lower than the upper surfaces of the plurality of battery cells 200.

[0033] Among them, even when the height of the second horizontal plane where the bottom end of the liquid outlet pipe 140 is located is lower than the height of the upper surfaces of the plurality of battery cells 200, through the liquid outlet structure 120 installed around the liquid outlet in this embodiment, it is only necessary to ensure that the height of the first horizontal plane where the communication opening 121 in the liquid outlet structure 120 is located is higher than the height of the upper surfaces of the plurality of battery cells 200, so as to realize that after the coolant submerges the plurality of battery cells 200, it is necessary to wait for the liquid level height of the coolant to rise to the height of the first horizontal plane before it will flow out from the liquid outlet pipe 140. Therefore, this embodiment ensures the cooling effect while reducing the requirement for the height of the liquid outlet when designing the battery pack housing 100, which is convenient for the design of the battery pack housing 100.

[0034] In some embodiments, please refer to Figure 3 . The communication opening 121 is provided at the top of the liquid outlet structure 120 and communicates with the top of the liquid outlet cavity 122. The liquid outlet structure 120 includes side plates 123. The side plates 123 face the liquid outlet and enclose at least a part of the liquid outlet cavity 122. The orthographic projection of the liquid outlet on the side plates 123 is located within the boundary of the side plates 123.

[0035] In this embodiment, by arranging the communication opening 121 formed by enclosing the upper ends of the side plates 123 facing the liquid outlet at the top of the liquid outlet structure 120, and the orthographic projection of the liquid outlet on the side plate 123 being located within the boundary of the side plate 123, that is, the pipe orifice at one end of the liquid outlet pipe 140 facing the box body installation cavity 130 is located in the liquid outlet cavity 122 of the liquid outlet structure 120. Therefore, when the coolant submerges the upper surfaces of multiple battery cells 200, the liquid level height of the coolant gradually rises to be higher than the top of the liquid outlet structure 120, and then flows into the liquid outlet cavity 122 from the communication opening 121, and finally is discharged from the box body 110 through the liquid outlet pipe 140.

[0036] In some embodiments, please refer to Figure 5 、 Figure 6 , Figure 5 is Figure 2 the top view structural schematic diagram of Figure 6 is Figure 5 the enlarged schematic diagram of part B in

[0037] It is easy to understand that D1*D2 is the area size of the communication opening 121 of the liquid outlet structure 120. In this embodiment, setting the area of the communication opening 121 to be larger than the cross-sectional area S1 of the inner diameter of the liquid outlet pipe 140 can make it so that when the liquid level height of the coolant in the box body installation cavity 130 gradually rises to the height of the first horizontal plane where the communication opening 121 is located, due to the relatively large area size of the communication opening 121, the liquid inlet rate of the coolant flowing into the liquid outlet cavity 122 from the communication opening 121 is also relatively fast. Thus, it is ensured that after the liquid level height of the coolant in the box body installation cavity 130 reaches the first horizontal plane where the communication opening 121 is located, the coolant exchange rate between the inside and outside of the box body installation cavity 130 is relatively fast, making the cooling effect of the coolant better.

[0038] If the area of the communication opening 121 is smaller than the cross-sectional area S1 of the inner diameter of the liquid outlet pipe 140, then the liquid inlet rate of the coolant flowing into the liquid outlet cavity 122 from the communication opening 121 is slower, which in turn leads to a slower liquid outlet rate of the coolant flowing from the liquid outlet cavity 122 into the liquid outlet pipe 140, and ultimately results in a general cooling effect of the coolant.

[0039] In this embodiment, the area of the communication opening 121 is set to be less than twice the cross-sectional area S1 of the inner diameter of the liquid outlet pipe 140 and greater than the cross-sectional area S1 of the inner diameter of the liquid outlet pipe 140. This can not only ensure a relatively fast liquid inlet rate of the coolant flowing from the communication opening 121 into the liquid outlet chamber 122, at which time the cooling effect of the coolant is better, but also ensure that the volume occupied by the liquid outlet structure 120 is small, so as to ensure a high space utilization rate of the box installation cavity 130.

[0040] In some embodiments, the inner diameter of the pipe orifice of the liquid outlet pipe 140 is r1, and the distance from the side of the side plate 123 close to the liquid outlet to the side of the box body 110 is D1, where 2*r1 > D1 > r1.

[0041] In this embodiment, by limiting the distance D1 from the side of the side plate 123 close to the liquid outlet to the side of the box body 110 to be greater than the inner diameter r1 of the pipe orifice of the liquid outlet pipe 140, it is ensured that the side plate 123 will not be too close to the pipe orifice of the liquid outlet pipe 140, thereby causing the liquid outlet rate of the coolant flowing from the liquid outlet chamber 122 into the liquid outlet pipe 140 to be slow, ultimately affecting the cooling effect of the coolant.

[0042] In some embodiments, the outer diameter of the liquid outlet pipe 140 is R1, and the length of the side plate 123 is D2, where R1 + 20mm > D2 > R1 + 10mm. In this embodiment, it is easy to understand that if it is necessary to ensure that the liquid outlet chamber 122 can accommodate one end of the liquid outlet pipe 140, it is necessary to ensure that the distance D1 from the side of the side plate 123 close to the liquid outlet to the side of the box body 110 is greater than the vertical distance V1 between the plane where the pipe orifice of the liquid outlet pipe 140 is located and the side, and at the same time, it is also necessary to satisfy that the length D2 of the side plate 123 is greater than the outer diameter R1 of the liquid outlet pipe 140. In the actual production process of the battery pack housing 100, it is necessary to fix the liquid outlet structure 120 around the liquid outlet pipe 140. When the fixing method is welding, weld beads often appear at the welding joint between the liquid outlet structure 120 and the side, so it is necessary to reserve some extra distance for the weld beads to exist. When the fixing method is bolt fixing, a certain gap is also required for the bolts to exist.

[0043] Therefore, in this embodiment, the length D2 of the side plate 123 is set to be greater than the outer diameter R1 of the liquid outlet pipe 140 and 10mm is reserved, that is, D2 > R1 + 10mm, for the existence of weld beads or bolts. In addition, in order to avoid the length D2 of the side plate 123 being too large and affecting the space utilization rate of the box installation cavity 130, in this embodiment, the length D2 of the side plate 123 is set to be less than the outer diameter R1 + 20mm of the liquid outlet pipe 140, so that the length of the side plate 123 meets the requirements for the occupation of weld beads or bolts during the fixation of the liquid outlet structure 120, and at the same time, the volume occupied by the liquid outlet structure 120 is small, so as to ensure the space utilization rate of the box installation cavity 130.

[0044] In some embodiments, please refer toFigure 7 and Figure 8 , Figure 7 is Figure 2 the front view structural schematic diagram of Figure 8 is Figure 7 the enlarged schematic diagram of part C in . The battery pack housing 100 further includes a cover plate 300. A housing installation opening 400 communicating with the housing installation cavity 130 is provided at the top of the housing 110. The cover plate 300 covers the housing installation opening 400. The distance between the cover plate 300 and the communication opening 121 is D3. The height difference between the first horizontal plane where the communication opening 121 is located and the upper surfaces of the plurality of battery cells 200 is H1. Among them, D3>5mm and H1>10mm.

[0045] In this embodiment, by defining that the distance D3 between the cover plate 300 and the communication opening 121 is greater than 5mm, it can be ensured that the liquid level height of the coolant located in the housing installation cavity 130 is always less than the installation opening of the housing 110, so that the amount of coolant in the housing installation cavity 130 will not be too full and cause overflow, thereby ensuring safety. At the same time, by defining that the height difference H1 between the first horizontal plane where the communication opening 121 is located and the upper surfaces of the plurality of battery cells 200 is greater than 10mm, it can be ensured that when the amount of coolant in the housing installation cavity 130 gradually increases to a stable state, the liquid level of the coolant is always higher than the upper surfaces of the plurality of battery cells 200, thus avoiding the limitation of the position design of the liquid outlet by the height of the battery module and making the design of the battery pack housing 100 more convenient.

[0046] In some embodiments, the width of the side plate 123 is D4, and the outer diameter of the liquid outlet pipe 140 is R1. Among them, R1 + 20mm>D4>R1 + 10mm. In this embodiment, the width D4 of the side plate 123 is defined to meet the requirements for the fillet weld or bolt occupancy when the liquid outlet structure 120 is fixed, and at the same time, the volume occupied by the liquid outlet structure 120 is relatively small, which is consistent with the beneficial effect of defining the length D2 of the side plate 123 in the above embodiment. For details, please refer to the above.

[0047] In some embodiments, the center of the liquid outlet is located on the center line in the width direction of the side plate 123.

[0048] In this embodiment, the center of the liquid outlet is set on the center line in the width direction of the side plate 123. This design ensures that the distance between the liquid outlet pipe 140 installed at this liquid outlet and the end plates at both ends in the length direction of the side plate 123 is equal. By making the position of the liquid outlet on the center line of the side plate 123, the symmetry between the liquid outlet and the two end plates can be effectively guaranteed, so as to reserve enough space on the side of the liquid outlet in the liquid outlet cavity 122, facilitating the fixation of the liquid outlet structure 120 on the side of the box body 110. This design aims to reserve sufficient space for welding beads or bolts, etc., providing convenience for the fixed installation of the liquid outlet structure 120.

[0049] In some cases, the thickness of the liquid outlet structure 120 usually ranges between 0.5 mm and 1.5 mm. In this embodiment, we set the thickness of the liquid outlet structure 120 to be greater than 0.5 mm to ensure that its strength can meet the required standards. At the same time, we also set the thickness of the liquid outlet structure 120 to be less than 1.5 mm to reduce the space it occupies, thereby maximizing the space utilization rate of the box body installation cavity 130. Such a design scheme finds a suitable compromise point between balancing the strength requirements of the liquid outlet structure 120 and the space utilization rate. By controlling the thickness of the liquid outlet structure 120 between 0.5 mm and 1.5 mm, we not only ensure its sufficient strength but also save space to the greatest extent, making the overall design more compact and efficient.

[0050] In some embodiments, when the liquid outlet structure 120 is fixed to the side of the box body 110 by welding, the welding positions are the two side plates 123 and the bottom plate connected to the side plate 123, and the two side plates 123 and the bottom plate are welded together by continuous welding to ensure the sealing between the two side plates 123, the bottom plate and the side of the box body 110. At the same time, the structural material of the liquid outlet structure 120 is the same as that of the box body 110 because the combination of the same materials is more likely to form a uniform weld, thereby improving the strength and stability of the welded joint, thus providing higher welding strength. It can also avoid the brittle fracture problem caused by the material difference between the two during welding. In addition, keeping the structural material of the liquid outlet structure 120 the same as that of the box body 110 makes their physical properties such as melting point also the same, so that the welding process is easier to control, thus ensuring the welding quality. This consistency helps to ensure the stability and controllability during the welding process, while improving the quality and reliability of the welded joint.

[0051] The present utility model provides a battery pack housing 100, which includes a box body 110 and a liquid outlet structure 120. Among them, the box body 110 is provided with a box body installation cavity 130, and a liquid outlet is formed in its side part, and the liquid outlet is used for installing a liquid outlet pipe 140 to discharge the coolant. The liquid outlet structure 120 is installed on the side part of the box body 110 and is located in the box body installation cavity 130, and is provided with a communication opening 121 and a liquid outlet cavity 122. The box body installation cavity 130 communicates with the liquid outlet through the communication opening 121 and the liquid outlet cavity 122 in sequence. The first horizontal plane where the communication opening 121 is located is higher than the upper surfaces of a plurality of battery cells 200 and higher than the second horizontal plane where the liquid outlet is located. When the coolant submerges the plurality of battery cells 200, the coolant then flows through the communication opening 121, the liquid outlet cavity 122, and the liquid outlet pipe 140 in sequence. Therefore, when the horizontal plane where the bottom end of the liquid outlet of the battery pack housing 100 provided by the present utility model is lower than the upper surfaces of the plurality of battery cells 200, it can still achieve that the coolant completely submerges the plurality of battery cells 200 and then is discharged from the liquid outlet.

[0052] An embodiment of the present utility model also provides a battery pack, which includes the above-mentioned battery pack housing 100. Compared with the related art, the immersion-type battery pack provided by the present utility model can not only provide a relatively uniform heat dissipation effect, reduce the temperature gradient of the battery, but also ensure that it occupies a smaller space under the same energy storage requirement, reduce the required materials and manufacturing costs under the same energy requirement, and reduce the production cost of the battery pack.

[0053] The above has introduced the embodiments of the present utility model in detail. Specific examples are used in this article to elaborate on the principle and implementation manner of the present utility model. The description of the above embodiments is only used to help understand the method and its core idea of the present utility model; at the same time, for those skilled in the art, according to the idea of the present utility model, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present utility model.

Claims

1. A battery pack housing, characterized in that: include: A box body is provided with a box body installation cavity, the box body installation cavity is used to contain coolant to immerse a plurality of battery cells, and a liquid outlet is provided on the side of the box body, the liquid outlet is used to install a liquid outlet pipe to discharge the coolant; as well as A liquid outlet structure, installed on the side of the box body, located in the box body installation cavity, and provided with a communicating opening and a liquid outlet cavity that are connected to each other; Among them, the box installation cavity is connected to the liquid outlet through the connecting opening and the liquid outlet cavity, the first horizontal plane where the connecting opening is located is higher than the upper surface of the multiple battery cells and the bottom of the liquid outlet cavity, and the second horizontal plane where the bottom end of the liquid outlet is located is lower than the first horizontal plane, so that the cooling liquid that immerses the multiple battery cells flows from the box installation cavity into the connecting opening, the liquid outlet cavity, and the liquid outlet pipe in sequence.

2. The battery pack housing according to claim 1, characterized in that: The second horizontal plane is lower than the upper surfaces of the plurality of battery cells.

3. The battery pack housing according to claim 1, characterized in that: The connecting opening is arranged at the top of the liquid outlet structure and connected to the top of the liquid outlet cavity. The liquid outlet structure includes a side plate, which is opposite to the liquid outlet and surrounds at least a part of the liquid outlet cavity. The positive projection of the liquid outlet on the side plate is located within the boundary of the side plate.

4. The battery pack housing according to claim 3, characterized in that: The distance from the side of the side plate close to the liquid outlet to the side portion is D1, the length of the side plate is D2, and the cross-sectional area of ​​the inner diameter of the liquid outlet pipe is S1; wherein, 2*S1>D1*D2>S1.

5. The battery pack housing according to claim 4, characterized in that: The inner diameter of the liquid outlet pipe is r1; wherein, 2*r1>D1>r1.

6. The battery pack casing according to claim 4, characterized in that: The outer diameter of the liquid outlet pipe is R1; wherein, R1+20mm>D2>R1+10mm.

7. The battery pack housing according to claim 3, characterized in that: It also includes a cover plate, and the top of the box is provided with a box installation opening connected to the box installation cavity, the cover plate covers the box installation opening, the distance between the cover plate and the connecting opening is D3, and the height difference between the first horizontal plane and the upper surface of the plurality of battery cells is H1; wherein D3>5mm, H1>10mm.

8. The battery pack casing according to claim 3, characterized in that: The width of the side plate is D4; wherein, R1+20mm>D4>R1+10mm.

9. The battery pack housing according to claim 3, characterized in that: The center of the liquid outlet is located on the center line of the side plate in the width direction.

10. A battery pack, characterized in that: Comprising a battery pack casing as described in any one of claims 1-9.

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