CN219959143U

CN219959143U - Battery pack

Info

Publication number: CN219959143U
Application number: CN202321252751.3U
Authority: CN
Inventors: 黄伟才; 杨绍
Original assignee: Eve Energy Co Ltd
Current assignee: Eve Energy Co Ltd
Priority date: 2023-05-23
Filing date: 2023-05-23
Publication date: 2023-11-03
Anticipated expiration: 2033-05-23

Abstract

The utility model discloses a battery pack, which comprises a box body, a battery pack, a cooling assembly and a liquid collecting box, wherein the battery pack is arranged in a first accommodating cavity of the box body; the cooling assembly is arranged in the first accommodating cavity and comprises a split-flow collecting pipe and at least two liquid cooling pipes, the split-flow collecting pipe is communicated with at least one of the water inlet interface, the first water outlet interface and the liquid cooling pipes through a connecting part, and the liquid cooling pipes are abutted against the electric core for cooling the electric core; the liquid collecting box is arranged in the first accommodating cavity, a second accommodating cavity is arranged in the liquid collecting box, and the connecting part is positioned in the second accommodating cavity. The first connecting part and the second connecting part on the cooling assembly are arranged in the second accommodating cavity of the liquid collecting box, the water pipe connector position and the battery pack can be separated, leaked cooling liquid is collected in the second accommodating cavity of the liquid collecting box and cannot flow into the area of the battery pack, and short circuit caused by soaking of the leaked cooling liquid of the battery pack is avoided.

Description

Battery pack

Technical Field

The utility model relates to the technical field of electricity storage equipment, in particular to a battery pack.

Background

With the increasing exhaustion of fossil energy sources such as petroleum, coal and natural gas and the increasing attention of people to environmental problems, especially the automobile manufacturing industry, great research is facing, and new energy automobiles are required to replace traditional fuel automobiles. Most new energy automobiles in the market adopt a battery pack as a main energy form of the new energy automobiles, and the performance of the battery pack can directly influence the overall performance of the new energy automobiles.

Although the waterproof requirement of the battery pack is strict, the battery pack is used in severe environments such as vibration, jolt and the like for a long time, and a liquid cooling system in the battery pack is easy to damage and leak; the leaked cooling liquid can flow everywhere in the battery pack, so that the battery pack module is easy to be damaged by water inflow and even short-circuit ignition occurs, and irrecoverable loss is caused for vehicles and passengers.

Disclosure of Invention

The aim of the embodiment of the utility model is that: provided is a battery pack which is less likely to cause short-circuiting and has high safety.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

provided is a battery pack including:

the box body is internally provided with a first accommodating cavity, and a water inlet interface and a first water outlet interface are arranged on the box body;

the battery pack is arranged in the first accommodating cavity and comprises a plurality of electric cores;

the cooling assembly is arranged in the first accommodating cavity and comprises a split-flow collecting pipe and at least two liquid cooling pipes, the split-flow collecting pipe is communicated with at least one of the water inlet interface, the first water outlet interface and the liquid cooling pipes through a connecting part, and the liquid cooling pipes are propped against the electric core and are used for cooling the electric core;

the liquid collecting box is arranged in the first accommodating cavity, a second accommodating cavity is arranged in the liquid collecting box, and the connecting part is positioned in the second accommodating cavity.

As a preferred scheme of the battery pack, the connecting parts comprise a first connecting part and a second connecting part, the first connecting part is arranged at two ends of the split-flow collecting pipe, the two first connecting parts are respectively communicated with the water inlet interface and the first water outlet interface, the second connecting part is arranged on the split-flow collecting pipe, and the split-flow collecting pipe is connected with the liquid cooling pipe through the second connecting part.

As a preferred aspect of the battery pack, the liquid collecting box is provided with one, and the flow dividing collecting pipe is positioned in the second accommodating cavity; or alternatively, the first and second heat exchangers may be,

the liquid collecting boxes are arranged in a plurality, and the liquid collecting boxes are arranged at least corresponding to the first connecting portions and the second connecting portions.

As a preferred scheme of battery package, including retrieving the subassembly, retrieve the subassembly and be used for absorbing the second holds the intracavity coolant liquid, retrieve the subassembly and include the recovery pipe, be provided with the second on the box and go out the water interface, the recovery pipe sets up the second holds the intracavity, the second goes out the water interface and runs through the liquid collecting box with the one end intercommunication of recovery pipe.

As a preferred scheme of the battery pack, the recycling assembly comprises a leakage sensor, and the leakage sensor is arranged at the bottom of the second accommodating cavity.

As a preferable scheme of the battery pack, the bottom of the second accommodating cavity is concavely provided with a liquid collecting tank, and one end of the recovery pipe, which is far away from the second water outlet, is arranged in the liquid collecting tank.

As a preferred scheme of the battery pack, a convex hull is arranged on the bottom surface of the liquid collecting box corresponding to the liquid collecting groove, an avoidance groove is formed in the bottom plate of the box body, and the convex hull is inserted into the avoidance groove.

As a preferred scheme of battery pack, be provided with a plurality of through-holes on the liquid collecting box, the liquid cooling pipe the inlet connection with first water outlet connection runs through respectively the through-hole, the lowest of through-hole with the bottom interval of second holding chamber.

As a preferred scheme of battery package, the liquid collecting box is including last box body and the lower box body of detachable connection, it is provided with first breach to go up the box body, be provided with the second breach on the lower box body, go up the box body with the lower box body is connected and is enclosed to form the second and hold the chamber, first breach with the second breach intercommunication is formed the through-hole.

As a preferable mode of the battery pack, the liquid collecting box is detachably connected with the box body.

As a preferred scheme of battery package, the reposition of redundant personnel collection pipe includes along the first body, second body, third body and the fourth body that coolant flow direction set gradually, first body with be provided with on the fourth body respectively first connecting portion, the second body with the third body stacks up and sets up, the entrance point and the exit end of liquid cooling pipe all are located the same end of liquid cooling pipe, follow the length direction interval of second body is provided with a plurality of second connecting portion, on the second body the second connecting portion with the entrance point intercommunication of liquid cooling pipe, follow the length direction interval of third body is provided with a plurality of second connecting portion, on the third body the second connecting portion with the exit end intercommunication of liquid cooling pipe.

As a preferable mode of the battery pack, the liquid collecting box is arranged on one side of the battery pack, and the upper surface of the liquid collecting box does not protrude out of the upper surface of the battery cell.

The beneficial effects of the utility model are as follows: the position of water piping connection portion is easiest to appear leaking, sets up the liquid collecting box, holds the intracavity with the second of connecting portion setting at the liquid collecting box, can separate connecting portion and group battery, if when leaking appears at first connecting portion or second connecting portion, the coolant liquid of spilling is collected in the second of liquid collecting box holds the intracavity, and can not flow into the region of group battery, avoids the group battery to be soaked by the coolant liquid of spilling and causes the short circuit, promotes the security performance of battery package.

Drawings

The utility model is described in further detail below with reference to the drawings and examples.

Fig. 1 is a schematic view of a battery pack according to an embodiment of the present utility model.

Fig. 2 is an enlarged schematic view of a portion of fig. 1 (upper case is not shown).

FIG. 3 is a schematic view of a housing and recovery assembly according to an embodiment of the present utility model.

Fig. 4 is a schematic cross-sectional view of a battery pack according to an embodiment of the present utility model.

Fig. 5 is a schematic cross-sectional view of a housing and recovery assembly according to an embodiment of the present utility model.

FIG. 6 is a schematic cross-sectional view of a tank and cooling assembly according to an embodiment of the utility model.

In the figure:

1. a battery pack; 11. a battery cell; 2. a case; 21. an avoidance groove; 22. a first accommodation chamber; 23. a water inlet port; 24. a first water outlet port; 25. a second water outlet port; 31. a shunt header; 311. a first tube body; 312. a second tube body; 313. a third tube body; 314. a fourth pipe body; 315. a first connection portion; 316. a second connecting portion; 32. a liquid-cooled tube; 4. a liquid collecting box; 41. an upper case; 42. a lower case; 421. a liquid collecting tank; 422. convex hulls; 43. a through hole; 44. a second accommodation chamber; 51. a recovery pipe; 52. and a liquid leakage sensor.

Detailed Description

In order to make the technical problems solved by the present utility model, the technical solutions adopted and the technical effects achieved more clear, the technical solutions of the embodiments of the present utility model will be described in further detail below with reference to the accompanying drawings, and it is obvious that the described embodiments are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to fall within the scope of the utility model.

In the description of the present utility model, unless explicitly stated and limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

As shown in fig. 1 to 4, the battery pack provided by the utility model comprises a box body 2, a battery pack 1, a cooling assembly and a liquid collecting box 4, wherein a first accommodating cavity 22 is arranged in the box body 2, and a water inlet interface 23 and a first water outlet interface 24 are arranged on the box body 2; the battery pack 1 is arranged in the first accommodating cavity 22, and the battery pack 1 comprises a plurality of electric cells 11; the cooling assembly is arranged in the first accommodating cavity 22, and comprises a split-flow collecting pipe 31 and at least two liquid cooling pipes 32, wherein the split-flow collecting pipe 31 is connected with at least one of the water inlet interface 23, the first water outlet interface 24 and the liquid cooling pipes 32 through connecting parts, and the liquid cooling pipes 32 are propped against the battery cells 11 for cooling the battery cells 11; the liquid collecting box 4 is arranged in the first accommodating cavity 22, a second accommodating cavity 44 is arranged in the liquid collecting box 4, and the connecting part is arranged in the second accommodating cavity 44. It can be understood that the liquid leakage is most likely to occur at the connecting part position of the water pipe, the liquid collecting box 4 is arranged, the connecting parts are all arranged in the second accommodating cavity 44 of the liquid collecting box 4, the connecting parts can be separated from the battery pack 1, if the liquid leakage occurs at the connecting parts, the leaked cooling liquid is collected in the second accommodating cavity 44 of the liquid collecting box 4 and cannot flow into the area of the battery pack 1, the short circuit caused by the soaking of the leaked cooling liquid of the battery pack 1 is avoided, and the safety performance of the battery pack is improved.

Further, the connecting portion includes a first connecting portion 315 and a second connecting portion 316, the first connecting portion 315 is disposed at two ends of the split-flow collecting pipe 31, the two first connecting portions 315 are respectively communicated with the water inlet port 23 and the first water outlet port 24, the split-flow collecting pipe 31 is provided with the second connecting portion 316, the second connecting portion 316 is communicated with the liquid cooling pipe 32, the first connecting portion 315 and the second connecting portion 316 are both located in the second accommodating cavity 44, and the liquid cooling pipe 32 penetrates through the liquid collecting box 4 to be connected with the second connecting portion 316. Through first connecting portion and second connecting portion, can make things convenient for the branch collection pipe to be connected with other pipelines, reduce the equipment degree of difficulty of battery package.

In this embodiment, the water inlet port 23 and the first water outlet port 24 may be communicated with an external refrigerator, the external refrigerator introduces low-temperature cooling liquid into the cooling assembly through the water inlet port 23, and extracts the cooling liquid in the cooling assembly through the first water outlet port 24 for secondary cooling and introduces the cooling liquid into the cooling assembly through the water inlet port 23 for recycling.

In this embodiment, the drip box 4 is provided with only one, the branch header 31 being located in the second containing chamber 44; only one liquid collecting box 4 is arranged, so that the number of parts in the battery pack can be reduced, the structure of the battery pack is simplified, and the installation is convenient; in other embodiments, the liquid collecting box 4 may be provided with a plurality of liquid collecting boxes 4, for example, corresponding to each of the first connecting portion 315 and the second connecting portion 316 and other interface portions, when liquid leakage occurs in one of the first connecting portion 315 or the second connecting portion 316, the leaked cooling liquid does not affect the other connecting portions, and the flowing range of the leaked cooling liquid is further limited.

Referring to fig. 3 and 5, further, in this embodiment, the battery pack is provided with only one liquid collecting box 4, the battery pack includes a recovery component for absorbing the cooling liquid in the second accommodating cavity 44, the recovery component includes a recovery pipe 51, the second water outlet 25 is provided on the tank 2, the recovery pipe 51 is provided in the second accommodating cavity 44, the second water outlet 25 penetrates through the liquid collecting box 4 to be communicated with one end of the recovery pipe 51, and the other end of the recovery pipe 51 is located at the bottom of the second accommodating cavity 44. By arranging the recovery component, the recovery component can recover the cooling liquid collected in the second accommodating cavity 44, so that secondary leakage caused by excessive cooling liquid in the second accommodating cavity 44 is avoided, and damage to components such as a BATTERY pack 1 or a BMS component (BATTERY management system) in the BATTERY pack is avoided; in this embodiment, the second water outlet 25 may be communicated with an external refrigerator, and after the refrigerator cools down, the coolant flows into the cooling assembly again through the water inlet 23 to cool down the battery cell 11 of the battery pack 1, at this time, the leaked coolant may participate in the cooling circulation operation of the battery cell 11 again, so that the flow of the coolant in the liquid cooling tube 32 may be ensured, thereby ensuring the heat dissipation effect of the cooling assembly on the battery cell 11.

Preferably, the recovery assembly includes a leakage sensor 52, the leakage sensor 52 being disposed at the bottom of the second receiving chamber 44. Through setting up weeping sensor 52, can monitor constantly whether the cooling module appears leaking the liquid phenomenon, when the weeping sensor 52 monitors that the cooling module takes place to leak the liquid, can start immediately and retrieve the subassembly, inhale the coolant liquid that spills away the second and hold chamber 44, avoid the second to hold in the chamber 44 too much coolant liquid and lead to secondary seepage, prevent that group battery 1 from intaking the short circuit. In the present embodiment, two liquid leakage sensors 52 are provided, and the two liquid leakage sensors 52 are arranged at intervals in the width direction of the battery pack.

In the present embodiment, the bottom of the second accommodating chamber 44 is concavely provided with a liquid collecting tank 421, and one end of the recovery pipe 51 away from the second water outlet 25 is disposed in the liquid collecting tank 421; it can be appreciated that under the action of gravity, water flows downwards, and the bottom of the second accommodating cavity 44 is provided with the liquid collecting tank 421, so that leaked cooling liquid can be collected in the liquid collecting tank 421, and at this time, the recovery effect of the recovery assembly on the cooling liquid is improved, and the residual quantity of the leaked cooling liquid in the second accommodating cavity 44 is reduced. Further, the bottom of the sump 421 may be inclined, and an end of the recovery pipe 51 remote from the second water outlet port 25 is disposed at the lowest position of the bottom of the sump 421. Of course, in other embodiments, the liquid collecting tank 421 may not be provided, only the bottom of the second accommodating chamber 44 is obliquely provided, and the end of the recovery pipe 51 away from the second water outlet 25 is disposed at the lowest position of the bottom of the second accommodating chamber 44, and at this time, the coolant leaked from the second accommodating chamber 44 will also collect at the lowest position of the bottom of the second accommodating chamber 44 under the action of gravity.

Further, the liquid collecting box 4 is detachably connected with the box body 2. Through setting up box 2 and the liquid collecting box 4 of detachable connection, can reduce the installation degree of difficulty of retrieving subassembly and cooling module, reduce the manufacturing cost of battery package. In this embodiment, the liquid collecting box 4 is connected with the box body 2 by a screw, and a fixing block is arranged on the liquid collecting box 4 and is used for installing the screw.

Further, the liquid collecting box 4 comprises an upper box body 41 and a lower box body 42 which are detachably connected, and the upper box body 41 and the lower box body 42 are connected and enclosed to form a second accommodating cavity 44. Through setting up box body 41 and lower box body 42, set up split type liquid collecting box 4 promptly, not only can reduce the processing degree of difficulty of liquid collecting box 4, can also reduce the installation degree of difficulty of cooling module and recovery subassembly, reduce the manufacturing cost of battery package. In this embodiment, the upper case 41 and the lower case 42 are connected by screws, and the upper case 41 and the lower case are provided with fixing blocks for mounting screws. In this embodiment, the lower case 42 is connected to the case 2 by screws.

In this embodiment, the liquid collecting tank 421 is disposed on the lower box 42, a convex hull 422 is disposed on the bottom surface of the lower box 42 corresponding to the area of the liquid collecting tank 421, an avoidance groove 21 is disposed on the bottom plate of the box 2, and the convex hull 422 is inserted into the avoidance groove 21; the convex hull 422 is arranged, so that the thickness of the lower box body 42 can be reduced, the wall thickness of the lower box body 42 is consistent, and in the embodiment, the liquid leakage sensor 52 is arranged in the liquid collecting groove 421, and preferably, the liquid collecting groove 421 is formed by stamping; through set up on the bottom plate of box 2 and dodge groove 21, on the one hand, dodge the convex closure 422 of box 42 under the groove 21 can dodge, promote the battery package inner space utilization, on the other hand, the convex closure 422 can provide spacingly with dodging the cooperation in groove 21, reduces the equipment degree of difficulty between liquid collecting box 4 and the box 2.

Specifically, the liquid collecting box 4 is provided with a plurality of through holes 43, the liquid cooling pipe 32, the water inlet port 23 and the first water outlet port 24 respectively penetrate through the through holes 43, and the lowest part of the through holes 43 is spaced from the bottom of the second accommodating cavity 44. In the present embodiment, since the split-flow header 31 is disposed in the second accommodating chamber 44 of the liquid collecting box 4, the provision of the through-hole 43 enables the liquid cooling tube 32, the water inlet port 23 and the first water outlet port 24 to communicate with the split-flow header 31 through the liquid collecting box 4; the lowest part of the through hole 43 is arranged at a distance from the second accommodating cavity 44, and when the leakage of the cooling liquid occurs, the height of the through hole 43 is higher than the liquid level of the cooling liquid, so that the cooling liquid can be prevented from flowing out of the liquid collecting box 4 from the position of the through hole 43, and the short circuit of the battery pack 1 caused by the flowing of the cooling liquid into the battery pack 1 is avoided.

In this embodiment, the upper case 41 is provided with a first notch, the lower case 42 is provided with a second notch, and when the upper case 41 and the lower case 42 are connected, the first notch and the second notch are connected to form a through hole 43. This reduces the height of the lower housing 42, thereby facilitating the assembled connection of the liquid cooling tube 32 to the second connection 316.

Further, the groove wall of the avoidance groove 21 on the bottom plate of the case 2 is spaced from the convex hull 422 on the lower case 42. Through setting up the cell wall that dodges groove 21 on the box 2 bottom plate and the convex closure 422 interval on the lower box body 42, if when the coolant liquid flows out the second from through-hole 43 holds chamber 44, under the effect of gravity, the coolant liquid that spills can be along the lateral wall down flow to the dodging inslot 21 of box 2 bottom plate of liquid collecting box 4, dodges in the inslot 21 can collect partial coolant liquid, can further avoid coolant liquid to flow to group battery 1 like this.

Referring to fig. 6, in the present embodiment, the split-flow header 31 includes a first pipe body 311, a second pipe body 312, a third pipe body 313 and a fourth pipe body 314 that are sequentially disposed along the flow direction of the coolant, first connecting portions 315 are disposed on the first pipe body 311 and the fourth pipe body 314, respectively, the second pipe body 312 is flush with two ends of the third pipe body 313, the second pipe body 312 is disposed in a stacked manner with the third pipe body 313, the inlet end and the outlet end of the liquid-cooled pipe 32 are both disposed at the same end of the liquid-cooled pipe 32, a plurality of second connecting portions 316 are disposed at intervals along the length direction of the second pipe body 312, the second connecting portions 316 on the second pipe body 312 are communicated with the inlet end of the liquid-cooled pipe 32, a plurality of second connecting portions 316 are disposed at intervals along the length direction of the third pipe body 313, and the second connecting portions 316 on the third pipe body 313 are communicated with the outlet end of the liquid-cooled pipe 32. By providing the second pipe 312 and the third pipe 313 in a stacked arrangement, the space in the second accommodating chamber 44 can be saved, the cooling liquid in the second pipe 312 flows in from the inlet end of the liquid cooling pipe 32, the channel flow in the liquid cooling pipe 32 cools the battery cell 11, then flows in from the outlet end of the liquid cooling pipe 32 into the third pipe 313 above the second pipe 312, and finally flows out of the battery pack through the fourth pipe 314. In this embodiment, the second connection portion 316 of the second pipe 312 and the third pipe 313 is a single integral unit, and a partition plate is disposed inside the integral unit to divide the interior of the integral unit into two independent channels, which are respectively connected to the second pipe 312 and the third pipe 313. In this embodiment, the second pipe body 312 and the third pipe body 313 are nylon pipes, the second pipe body 312 includes a plurality of first pipe body segments, two adjacent first pipe body segments are connected by a second connecting portion 316, the third pipe body 313 includes a plurality of second pipe body segments, two adjacent second pipe body segments are connected by a second connecting portion 316, the first connecting portion 315 is a quick-connection plug, the first pipe body 311 is connected with the water inlet interface 23 by a quick-connection plug, and correspondingly, the first pipe body 311 is connected with the second pipe body 312, the third pipe body 313 is connected with the fourth pipe body 314, and the fourth pipe body 314 is connected with the first water outlet by a quick-connection plug.

Further, the liquid collecting box 4 is provided at one side of the battery pack 1, and the upper surface of the liquid collecting box 4 does not protrude from the upper surface of the battery cell 11. Through setting up the upper surface of collecting box 4 and not protruding in the upper surface of electric core 11, can reduce the influence of collecting box 4 to the battery package size, avoid collecting box 4 to increase the thickness of battery package, guarantee the energy density of battery package.

In this embodiment, the water inlet port 23, the first water outlet port 24 and the second water outlet port 25 are all fixed on the case 2 by welding, so that a gap between the ports and the case 2 can be avoided.

In the description herein, it should be understood that the terms "upper," "lower," "left," "right," and the like are based on the orientation or positional relationship shown in the drawings, and are merely for convenience of description and to simplify the operation, rather than to indicate or imply that the apparatus or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the utility model. Furthermore, the terms "first," "second," and the like, are used merely for distinguishing between descriptions and not for providing a special meaning.

In the description herein, reference to the term "one embodiment," "an example," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the utility model. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples.

Furthermore, it should be understood that although the present disclosure describes embodiments, not every embodiment is provided with a separate embodiment, and that this description is provided for clarity only, and that the disclosure is not limited to the embodiments described in the foregoing embodiments, and that the embodiments described in the foregoing embodiments may be combined appropriately to form other embodiments that will be understood by those skilled in the art.

The technical principle of the present utility model is described above in connection with the specific embodiments. The description is made for the purpose of illustrating the general principles of the utility model and should not be taken in any way as limiting the scope of the utility model. Other embodiments of the utility model will be apparent to those skilled in the art from consideration of this specification without undue burden.

Claims

1. A battery pack, comprising:

2. The battery pack according to claim 1, wherein the connection portion includes a first connection portion and a second connection portion, the first connection portion is provided at both ends of the split header, the two first connection portions are respectively communicated with the water inlet port and the first water outlet port, the second connection portion is provided on the split header, and the split header and the liquid cooling pipe are connected by the second connection portion.

3. The battery pack of claim 2, wherein said header is provided with one and said manifold is located within said second receiving cavity; or alternatively, the first and second heat exchangers may be,

4. A battery pack according to any one of claims 1 to 3, comprising a recovery assembly for absorbing the cooling liquid in the second receiving chamber, the recovery assembly comprising a recovery tube provided with a second water outlet port on the tank, the recovery tube being provided in the second receiving chamber, the second water outlet port communicating with one end of the recovery tube through the liquid collecting box.

5. The battery pack of claim 4, wherein the recovery assembly includes a leakage sensor disposed at a bottom of the second receiving chamber.

6. The battery pack according to claim 4, wherein the bottom of the second accommodating chamber is concavely provided with a liquid collecting tank, and an end of the recovery pipe away from the second water outlet port is disposed in the liquid collecting tank.

7. The battery pack according to claim 6, wherein a convex hull is arranged on the bottom surface of the liquid collecting box in a region corresponding to the liquid collecting groove, an avoidance groove is arranged on the bottom plate of the box body, and the convex hull is inserted into the avoidance groove.

8. A battery pack according to any one of claims 1 to 3, wherein the liquid collecting box is provided with a plurality of through holes, the liquid cooling pipe, the water inlet port and the first water outlet port respectively penetrate through the through holes, and the lowest part of the through holes is spaced from the bottom of the second accommodating cavity.

9. The battery pack according to claim 8, wherein the liquid collecting box comprises an upper box body and a lower box body which are detachably connected, the upper box body is provided with a first notch, the lower box body is provided with a second notch, the upper box body and the lower box body are connected and enclosed to form the second accommodating cavity, and the first notch and the second notch are communicated to form the through hole.

10. A battery pack according to any one of claims 1 to 3, wherein the header box is detachably connected to the case.

11. The battery pack according to claim 2 or 3, wherein the split header includes a first pipe body, a second pipe body, a third pipe body and a fourth pipe body which are sequentially arranged along a flow direction of the coolant, the first pipe body and the fourth pipe body are respectively provided with the first connecting portion, inlet ends and outlet ends of the liquid cooling pipes are both located at the same end of the liquid cooling pipes, a plurality of second connecting portions are arranged at intervals along a length direction of the second pipe body, the second connecting portions on the second pipe body are communicated with an inlet end of the liquid cooling pipes, a plurality of second connecting portions are arranged at intervals along a length direction of the third pipe body, and the second connecting portions on the third pipe body are communicated with an outlet end of the liquid cooling pipes.