CN220456556U

CN220456556U - Battery pack and liquid cooling system

Info

Publication number: CN220456556U
Application number: CN202321981091.2U
Authority: CN
Inventors: 周梦; 陈英旗; 曹楷; 曹辉
Original assignee: Shanghai Ruipu Energy Co Ltd
Current assignee: Shanghai Ruipu Energy Co Ltd
Priority date: 2023-07-25
Filing date: 2023-07-25
Publication date: 2024-02-06
Anticipated expiration: 2033-07-25

Abstract

The utility model discloses a battery pack and a liquid cooling system, and relates to the technical field of batteries, on one hand, the battery pack comprises a plurality of liquid cooling plates, a water inlet pipe, a water outlet pipe and electric core units which are arranged at intervals, a plurality of installation spaces for installing the electric core units are formed between two adjacent liquid cooling plates, and each electric core unit comprises a plurality of electric cores; the water inlet pipe and the water outlet pipe are arranged along the arrangement direction of the liquid cooling plate and are respectively positioned at two ends of the liquid cooling plate in the length direction; the first communication pipelines and the second communication pipelines are respectively arranged in two adjacent installation spaces and are used for being communicated with two liquid cooling plates forming the installation spaces, and the first communication pipelines and the second communication pipelines are respectively arranged at two ends of the length direction of the liquid cooling plates so as to enable the electric cores of the electric core units in the adjacent installation spaces to be staggered. On the other hand, still provide a liquid cooling system. The application solves the problem that the battery pack has a large weight and a small energy density for improving the heat exchange effect.

Description

Battery pack and liquid cooling system

Technical Field

The utility model relates to the technical field of batteries, in particular to a battery pack and a liquid cooling system.

Background

The battery system is a key part of the electric automobile and provides power for the whole automobile. The chemical reaction of the battery cell in the charge and discharge process can generate heat, so that the temperature inside the battery cell can be increased, and the temperature rise phenomenon is more serious especially under the conditions of high current and high power charge and discharge. And as the temperature of the battery cell increases, the performance of the battery cell is greatly attenuated, and even safety accidents can be caused. In addition, a plurality of battery cells are generally arranged in the battery module or the system, when the heat dissipation condition of a single battery cell is poor, the heat dissipation of other battery cells in the whole battery pack can be seriously influenced, so that the heat dissipation effect and the heat dissipation efficiency of the battery pack are poor, the working performance of the battery pack is further influenced, and even thermal runaway is caused.

In the heat management scheme of the prior art, when a battery liquid cooling plate is arranged at the bottom of a battery, a large amount of heat conducting glue is used for fixing a battery core on the bottom liquid cooling plate, then the liquid cooling plate and the battery are fixed in a battery box body through a structural member, or a plurality of liquid cooling plates are arranged at the bottom of a module consisting of the battery cores, a battery cooling system is formed through a pipeline, and the cooling system and the module are fixed in the battery box body through the structural member. In the prior art, the contact area of the liquid cooling plate and the battery cell is small, the heat exchange rate is low, and the heat dissipation effect is poor. When the battery liquid cooling plate is arranged on the side face of the battery core, a large number of pipelines are required to be arranged so as to communicate liquid cooling channels between the liquid cooling plates and communicate with an external liquid cooling component, so that the weight of the battery pack is increased, and meanwhile, when the battery core is arranged, the space for arranging the battery core is limited due to the fact that the communicating pipelines occupy the arrangement space, and the volume energy density of the battery pack is reduced.

Disclosure of Invention

Aiming at the defects in the prior art, the utility model aims to provide a liquid cooling system and a battery pack so as to solve the problem that the volume energy density of the battery pack is smaller for improving the heat exchange effect in the prior art.

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

in one aspect, the present application provides a battery pack comprising:

a plurality of liquid cooling plates which are arranged at intervals, wherein an installation space is formed between two adjacent liquid cooling plates;

the battery cell units are arranged in the installation space, and each battery cell unit comprises a plurality of battery cells;

the water inlet pipe and the water outlet pipe are arranged along the arrangement direction of the liquid cooling plate and are respectively positioned at two ends of the liquid cooling plate in the length direction;

wherein, install first communicating pipe and second communicating pipe respectively in two adjacent installation spaces, above-mentioned first communicating pipe and above-mentioned second communicating pipe are used for the intercommunication to constitute two liquid cooling boards of this installation space, and above-mentioned first communicating pipe and above-mentioned second communicating pipe are located the both ends of above-mentioned liquid cooling board length direction respectively to make the electric core staggered arrangement of electric core unit that is located adjacent above-mentioned installation space.

In some alternative embodiments, the first communicating pipe and the second communicating pipe are three-way connectors, a water gap of the three-way connectors is communicated with the water inlet pipe or the water outlet pipe, and the other two water gaps are respectively communicated with two adjacent liquid cooling plates.

In some alternative embodiments, a plurality of water inlet connectors communicated with the first communicating pipe are arranged along the length direction of the water inlet pipe at intervals, and a plurality of water outlet connectors communicated with the second communicating pipe are arranged along the length direction of the water outlet pipe at intervals.

In some alternative embodiments, two sides of the liquid cooling plate are respectively provided with a cooling liquid communication interface communicated with the first communication pipe and the second communication pipe, and the two cooling liquid communication interfaces are respectively positioned at two ends of the length direction of the liquid cooling plate.

In some alternative embodiments, the device further comprises a box body, wherein a partition plate is arranged in the box body, the partition plate divides the box body into a containing cavity and a cell cavity, the liquid cooling plate is positioned in the cell cavity, and the water inlet pipe and the water outlet pipe are positioned in the containing cavity.

In some alternative embodiments, the inlet pipe and the outlet pipe are each formed by a duct board connected to the partition plate.

In some alternative embodiments, the duct board is an L-shaped board, located outside the partition board away from the cell cavity, the duct board and the partition board form the water inlet pipe and the water outlet pipe, and the duct board and the side wall of the box form a crumple cavity.

In some alternative embodiments, a cooling channel is disposed in the box and is in communication with the water inlet pipe and the water outlet pipe, and the cooling channel is configured to be disposed at the bottom of the BDU.

In some alternative embodiments, the box body is provided with a water inlet pipe joint communicated with the water inlet pipe and a water outlet pipe joint communicated with the water outlet pipe.

In a second aspect, the present application further provides a liquid cooling system, including:

a plurality of liquid cooling plates which are arranged at intervals, and an installation space for placing the battery core is formed between two adjacent liquid cooling plates;

Compared with the prior art, the utility model has the advantages that: through with two above-mentioned liquid cooling boards of arbitrary installation space and inlet tube intercommunication through first communicating pipe, and two above-mentioned liquid cooling boards of adjacent installation space pass through second communicating pipe and outlet pipe intercommunication, and above-mentioned first communicating pipe and second communicating pipe are located above-mentioned liquid cooling board length direction's both ends, thereby only need install a first communicating pipe or second communicating pipe in each installation space, reduce the quantity of arranging of first communicating pipe and second communicating pipe, make the electric core of the electric core unit that is located adjacent installation space can staggered arrangement, not only increased the arrangement space of electric core, the weight of battery package box has been alleviateed, make battery package volume energy density increase, and strengthened the structural stability of battery package.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

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

fig. 2 is a schematic diagram illustrating an arrangement of the battery cells in fig. 1.

FIG. 3 is an exploded view of a liquid cooling system according to the present utility model;

FIG. 4 is a schematic front view of FIG. 3;

fig. 5 is a schematic cross-sectional view of fig. 4.

In the figure: 1. a liquid cooling plate; 11. a cooling liquid communication interface; 2. a first communication pipe; 3. a second communicating pipe; 4. a water inlet pipe; 41. a water inlet joint; 5. a water outlet pipe; 51. a water outlet joint; 6. a cell unit; 61. a battery cell; 7. a third communicating pipe; 8. a fourth communicating pipe; 9. a case; 90. a crush chamber; 91. a cooling channel; 92. a water inlet pipe joint; 93. a water outlet pipe joint; 94. a duct board; 95. partition boards; 96. a partition plate; 10. BDU.

Detailed Description

For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present application based on the embodiments herein.

Embodiments of a liquid cooling system and a battery pack according to the present utility model are described in further detail below with reference to the accompanying drawings.

On the one hand, as shown in fig. 1, the application provides a battery pack, including a plurality of liquid cooling boards 1, a plurality of electric core unit 6, inlet tube 4 and outlet pipe 5, liquid cooling board 1 is used for pasting to establish in electric core unit 6's both sides, cools down electric core unit 6, and the coolant liquid in liquid cooling board 1 flows in and flows out from outlet pipe 5 from inlet tube 4, forms cooling cycle.

Specifically, a plurality of liquid cooling plates 1 are arranged at intervals, and an installation space is formed between two adjacent liquid cooling plates 1; a plurality of battery cells 6 are disposed in the installation space, each of the battery cells 6 including a plurality of battery cells 61; the water inlet pipe 4 and the water outlet pipe 5 are arranged along the arrangement direction of the liquid cooling plate 1 and are respectively positioned at two ends of the liquid cooling plate 1 in the length direction; wherein, a first communicating pipe 2 and a second communicating pipe 3 are respectively installed in two adjacent installation spaces, the first communicating pipe 2 and the second communicating pipe 3 are used for communicating two liquid cooling plates 1 forming the installation space, and the first communicating pipe 2 and the second communicating pipe 3 are respectively located at two ends of the liquid cooling plates 1 in the length direction, so that the electric cores 61 of the electric core units 6 located in the adjacent installation spaces are staggered.

It will be understood that, as shown in fig. 1 and 2, the battery cell unit 6 includes a plurality of battery cells 61 arranged along the length direction of the liquid cooling plate 1, and since one first communication tube 2 or one second communication tube 3 is installed in each installation space, and the first communication tube 2 and the second communication tube 3 in two adjacent installation spaces are respectively arranged at two ends of the length direction of the liquid cooling plate 1, the battery cells 61 installed in the two adjacent installation spaces form a staggered arrangement. Because in each installation space, only unilaterally arrange first communicating pipe 2 or second communicating pipe 3, consequently in each installation space, be used for arranging the space of electric core 61 and promote, set up like this not only can improve the volume energy density of battery package, can provide the support each other between the adjacent electric core 61 simultaneously, reduced the liquid cooling board 1 to the support load of electric core 61, also made the whole rigidity reinforcing of battery package, improved the structural stability of battery package.

Preferably, the liquid cooling plates 1 are attached to two sides of the electric core unit 6, and can be adhered to the electric core unit 6 by using a heat conduction structure adhesive, so that the electric core unit 6 is cooled.

The two liquid cooling plates 1 in any one installation space are two adjacent liquid cooling plates 1 forming the installation space, and one of the liquid cooling plates 1 and the other adjacent liquid cooling plate 1 form an installation space adjacent to the installation space. Therefore, only one first communication pipe 2 or one second communication pipe 3 is required to be installed in each installation space, the cooling liquid in the water inlet pipe 4 can flow into the liquid cooling channel in each liquid cooling plate 1 through the first communication pipe 2, and then flow out into the water outlet pipe 5 through the second communication pipe 3, the flowing directions of the cooling liquid of all the liquid cooling plates 1 are the same, and all the liquid cooling plates 1 are in parallel connection.

Compared with the prior art, the connecting pipelines are required to be installed at the two ends of each liquid cooling plate, so that the liquid cooling plates are communicated with the water inlet pipe and the water outlet pipe, the arrangement structure can reduce the arrangement quantity of the first communication pipes 2 and the second communication pipes 3, the arrangement space of the battery cell unit is improved, the weight of the battery pack box body is reduced, and the volume energy density of the battery pack is increased.

In this example, each liquid cooling plate 1 is provided with a cooling channel for cooling liquid to circulate, and the cooling channels may be a channel or two serpentine channels uniformly distributed, and may have different internal cooling channels according to the shapes of different liquid cooling plates 1, which will not be described herein.

It should be noted that, the two liquid cooling plates 1 forming the installation space are communicated with the water inlet pipe 4 through the first communication pipe 2 or communicated with the water outlet pipe 5 through the second communication pipe 3, and the two liquid cooling plates 1 located at the outermost side are also communicated with the water outlet pipe 5 and the water inlet pipe 4 respectively.

In some alternative embodiments, the two liquid cooling plates 1 located at the outermost sides are respectively communicated with the water inlet pipe 4 and the water outlet pipe 5 through the third communicating pipe 7 and the fourth communicating pipe 8. In this example, the third communication pipe 7 and the fourth communication pipe 8 are each L-shaped bent pipes.

In some alternative embodiments, the first communicating pipe 2 and the second communicating pipe 3 are three-way connectors, one water gap of the three-way connectors is communicated with the water inlet pipe 4 or the water outlet pipe 5, and the other two water gaps are respectively communicated with two adjacent liquid cooling plates 1.

In some alternative embodiments, a plurality of water inlet connectors 41 are provided along the length direction of the water inlet pipe 4 at intervals, and a plurality of water outlet connectors 51 are provided along the length direction of the water outlet pipe 5 at intervals, and are communicated with the second communication pipe 3.

It will be appreciated that the water inlet joint 41 communicates with one water port of the first communication pipe 2, and the water outlet joint 51 communicates with one water port of the second communication pipe 3. Each water inlet joint 41 or water outlet joint 51 is located in one installation space, and one water inlet joint 41 and one water outlet joint 51 are respectively arranged in two adjacent installation spaces. That is, all the water inlet connectors 41 are disposed one by one at a mounting space, and all the water outlet connectors 51 are also disposed one by one at a mounting space.

In some alternative embodiments, two sides of the liquid cooling plate 1 are respectively provided with a cooling liquid communication interface 11 that communicates with the first communication pipe 2 and the second communication pipe 3, and the two cooling liquid communication interfaces 11 are respectively located at two ends of the side liquid cooling plate 1 in the length direction.

In order to optimize the cooling effect of the liquid cooling plates 1, the arrangement of the battery cells 61 in the installation space is also considered, the cooling liquid communication interfaces 11 are provided at both ends of the liquid cooling plates 1 in the length direction, and one cooling liquid communication interface 11 is provided at both sides of each liquid cooling plate 1, so that the two liquid cooling plates 1 can be communicated.

In some alternative embodiments, as shown in fig. 3 to 5, the battery pack according to any one of the above embodiments further includes a case 9, wherein a partition plate 95 is disposed in the case 9, the partition plate 95 divides the case 9 into a receiving chamber and a cell chamber, the liquid cooling plate 1 is disposed in the cell chamber, and the water inlet pipe 4 and the water outlet pipe 5 are disposed in the receiving chamber.

For example, the case 9 may alternatively have a cavity, and the partition plate 95 is provided with a piece dividing the cavity into an upper cell cavity and a lower accommodating cavity. The liquid cooling plate 1 is arranged in the electric core cavity, the water inlet pipe 4 and the water outlet pipe 5 are positioned in the accommodating cavity at the lower part, a plurality of through holes for installing the water inlet joint 41 and the water outlet joint 51 are formed in the partition plate 95, and the water inlet pipe 4 and the water outlet pipe 5 are respectively communicated with the liquid cooling plate 1 positioned in the electric core cavity through the water inlet joint 41 and the water outlet joint 51.

In this example, two partition plates 95 are provided, which are respectively located in the case 9 and on both sides in the longitudinal direction of the liquid cooling plate 1, so as to divide the case 9 into a core chamber and accommodating chambers located on both sides of the core chamber. The water inlet pipe 4 and the water outlet pipe 5 are respectively positioned in the two accommodating cavities at two sides, a plurality of through holes for installing the water inlet joint 41 and the water outlet joint 51 are formed in the partition plate 95, and the water inlet pipe 4 and the water outlet pipe 5 are respectively communicated with the liquid cooling plate 1 positioned in the electric core cavity through the water inlet joint 41 and the water outlet joint 51. The advantage of this arrangement is that the height of the box 9 can be reduced and the space utilization in the box can be further increased.

In some alternative embodiments, the above-mentioned liquid cooling plate 1 may be connected to the partition plate 95 through a heat-conducting structural adhesive, so that the liquid cooling plate 1 is vertically set on the partition plate 95, and of course, other fixing manners may be used, for example, the liquid cooling plate may be fixed in the cell cavity through the cell unit 6.

The size of the box 9 can be set according to the arrangement requirement of the battery cell unit 6 and the size of the liquid cooling plate 1. In this example, the distance between the two partition plates 95 in the case 9 is the same as the length of the liquid cooling plate 1, so that two ends of the liquid cooling plate 1 in the length direction can be tightly attached to the two partition plates 95.

In some alternative embodiments, both the inlet pipe 4 and the outlet pipe 5 are formed by a duct plate 94 connected to the partition 95.

In this example, the conduit plate 94 is an L-shaped plate, and is located on the outer side of the partition plate 95 away from the core cavity, the conduit plate 94 and the partition plate 95 form the water inlet pipe 4 and the water outlet pipe 5, and the conduit plate 94 and the side wall of the tank 9 form the crumple cavity 90 to protect the water inlet pipe 4 and the water outlet pipe 5, so as to prevent the tank 9 from being broken when being broken by external force such as impact, and the water inlet pipe 4 and the water outlet pipe 5 are caused.

In some alternative embodiments, a cooling channel 91 is provided in the box 9 and communicates with the water inlet pipe 4 and the water outlet pipe 5, and the cooling channel 91 is configured to be disposed at the bottom of the BDU 10.

It can be understood that the BDU (battery energy distribution unit) is an important component on the high-voltage circuit of the electric vehicle, which controls the power-on and power-off process, the pre-charging process and the charging process of the high-voltage circuit, and whether the characteristic parameters of the BDU product meet the qualification conditions has an important influence on the service life of the whole vehicle, the control strategy and the high-voltage electric safety. Thus, cooling channels 91 are arranged at the bottom of the BDU to cool the BDU. In this example, a spacer 96 is also provided between the BDU and the cell unit 6.

In some alternative embodiments, the tank 9 is provided with a water inlet pipe joint 92 communicating with the water inlet pipe 4 and a water outlet pipe joint 93 communicating with the water outlet pipe 5.

The water inlet pipe 4 and the water outlet pipe 5 are connected with an external liquid cooling unit through a water inlet pipe joint 92 and a water outlet pipe joint 93. The external liquid cooling unit has the functions of cooling and flowing the cooling medium, and forms a loop with the water inlet pipe 4, the water outlet pipe 5, the cooling channel 91 and the cooling channel inside the liquid cooling plate 1 of the liquid cooling system, so that the external liquid cooling unit can cool the battery and make the cooling medium circularly flow. Therefore, the heat in the liquid cooling system is carried to the outside of the system by the cooling medium, and the cooled cooling medium flows into the liquid cooling system through the water inlet pipe joint 92 to be circulated in a reciprocating manner so as to cool the electric core 61 by heat dissipation.

Alternatively, the water inlet pipe joint 92 and the water outlet pipe joint 93 are respectively fixed on the box body 9 by brazing, and correspond to the positions of the water inlet pipe 4 and the water outlet pipe 5.

On the other hand, as shown in fig. 3-5, the application also provides a liquid cooling system, which comprises a plurality of liquid cooling plates 1, a water inlet pipe 4 and a water outlet pipe 5 which are arranged at intervals, wherein an installation space for placing a battery cell unit 6 is formed between two adjacent liquid cooling plates 1; the water inlet pipe 4 and the water outlet pipe 5 are arranged along the arrangement direction of the liquid cooling plate 1 and are respectively positioned at two ends of the liquid cooling plate 1 in the length direction; wherein, a first communicating pipe 2 and a second communicating pipe 3 are respectively installed in two adjacent installation spaces, the first communicating pipe 2 and the second communicating pipe 3 are used for communicating two liquid cooling plates 1 forming the installation space, and the first communicating pipe 2 and the second communicating pipe 3 are respectively located at two ends of the liquid cooling plates 1 in the length direction, so that the electric cores 61 of the electric core units 6 located in the adjacent installation spaces are staggered.

According to the battery pack and the liquid cooling system, the two liquid cooling plates 1 of any installation space are communicated with the water inlet pipe 4 through the first communicating pipe 2, the two liquid cooling plates 1 of the adjacent installation space are communicated with the water outlet pipe 5 through the second communicating pipe 3, and the first communicating pipe 2 and the second communicating pipe 3 are positioned at two ends of the liquid cooling plate 1 in the length direction, so that only one first communicating pipe 2 or one second communicating pipe 3 is needed to be installed in each installation space, the arrangement quantity of the first communicating pipe 2 and the second communicating pipe 3 is reduced, the arrangement space of the battery cell units 6 is increased, the weight of a battery pack box body is reduced, and the battery cells 61 of the battery cell units 6 in the adjacent two installation spaces are staggered, so that the volume energy density of the battery pack is increased, and the structural stability of the battery pack is also improved; two partition plates 95 are arranged in the box body 9 and are respectively positioned at two sides of the box body 9 in the length direction of the liquid cooling plate 1, so that a containing cavity is formed with the side wall of the box body 9 to form the water inlet pipe 4 and the water outlet pipe 5, the height of the box body 9 can be reduced, and the space utilization rate in the box body can be further increased; by arranging the L-shaped pipeline plate 94, the collapsing cavity 90 is formed with the side wall of the box body 9 so as to protect the water inlet pipe 4 and the water outlet pipe 5 and prevent the box body 9 from being broken when being broken by external force such as impact and the like, so that the water inlet pipe 4 and the water outlet pipe 5 are prevented from being broken.

In the description of the present application, it should be noted that the azimuth or positional relationship indicated by the terms "upper", "lower", etc. are based on the azimuth or positional relationship shown in the drawings, and are merely for convenience of description of the present application and simplification of the description, and are not indicative or implying that the apparatus or element in question must have a specific azimuth, be configured and operated in a specific azimuth, and thus should not be construed as limiting the present application. Unless specifically stated or limited otherwise, the terms "mounted," "connected," and "coupled" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art as the case may be.

It should be noted that in this application, relational terms such as "first" and "second" and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The foregoing is merely a specific embodiment of the application to enable one skilled in the art to understand or practice the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A battery pack, comprising:

a plurality of liquid cooling plates (1) which are arranged at intervals, wherein an installation space is formed between two adjacent liquid cooling plates (1);

a plurality of battery cell units (6) arranged in the installation space, wherein each battery cell unit (6) comprises a plurality of battery cells (61);

the water inlet pipe (4) and the water outlet pipe (5), wherein the water inlet pipe (4) and the water outlet pipe (5) are arranged along the arrangement direction of the liquid cooling plate (1) and are respectively positioned at two ends of the liquid cooling plate (1) in the length direction;

wherein, install first communicating pipe (2) and second communicating pipe (3) respectively in two adjacent installation spaces, first communicating pipe (2) with second communicating pipe (3) are used for the intercommunication to constitute two liquid cooling boards (1) of this installation space, just first communicating pipe (2) with second communicating pipe (3) are located respectively liquid cooling board (1) length direction's both ends to make be located adjacently electric core (61) of electric core unit (6) in the installation space are staggered arrangement.

2. The battery pack according to claim 1, wherein the first communication pipe (2) and the second communication pipe (3) are three-way connectors, a water port of the three-way connectors is communicated with the water inlet pipe (4) or the water outlet pipe (5), and the other two water ports are respectively communicated with two adjacent liquid cooling plates (1).

3. The battery pack according to claim 1, wherein a plurality of water inlet connectors (41) communicated with the first communicating pipe (2) are arranged at intervals along the length direction of the water inlet pipe (4), and a plurality of water outlet connectors (51) communicated with the second communicating pipe (3) are arranged at intervals along the length direction of the water outlet pipe (5).

4. The battery pack according to claim 1, wherein both sides of the liquid cooling plate (1) are respectively provided with a cooling liquid communication interface (11) which communicates with the first communication pipe (2) and the second communication pipe (3), and both the cooling liquid communication interfaces (11) are respectively located at both ends of the liquid cooling plate (1) in the length direction.

5. The battery pack according to any one of claims 1-4, further comprising a box body (9), wherein a partition baffle plate (95) is arranged in the box body (9), the partition baffle plate (95) divides the box body (9) into a containing cavity and a cell cavity, the liquid cooling plate (1) is positioned in the cell cavity, and the water inlet pipe (4) and the water outlet pipe (5) are positioned in the containing cavity.

6. A battery pack according to claim 5, wherein the inlet pipe (4) and the outlet pipe (5) are each formed by a duct plate (94) connected to the partition plate.

7. The battery pack according to claim 6, wherein the duct plate (94) is an L-shaped plate located outside the partition plate (95) away from the cell cavity, the duct plate (94) and the partition plate (95) form the water inlet pipe (4) and the water outlet pipe (5), and the duct plate (94) and the side wall of the case (9) form a crumple chamber (90).

8. A battery pack according to claim 6, wherein a cooling channel (91) communicating with the water inlet pipe (4) and the water outlet pipe (5) is provided in the box (9), and the cooling channel (91) is arranged at the bottom of the BDU (10).

9. A battery pack according to claim 5, wherein the tank (9) is provided with a water inlet pipe joint (92) communicating with the water inlet pipe (4) and a water outlet pipe joint (93) communicating with the water outlet pipe (5).

10. A liquid cooling system, comprising:

a plurality of liquid cooling plates (1) which are arranged at intervals, wherein an installation space for placing the battery cell unit (6) is formed between two adjacent liquid cooling plates (1);