Power battery system pressure relief assembly

Abstract

A power battery system pressure relief assembly, used for a power battery system, and comprising a flow guide pipe and an explosion-proof valve (2). The flow guide pipe is provided with flow collecting sections (11) and flow converging sections (12). Each flow collecting section (11) is provided with a first port and a second port. The first port is communicated with a corresponding battery module (4) of the power battery system, and the second port is communicated with the corresponding flow converging section (12). One end of the explosion-proof valve (2) is communicated with the flow converging sections (12), and the other end of the explosion-proof valve (2) is communicated with the outside of the power battery system.

Description

A power battery system pressure relief assembly

[0001] The present application claims priority to the Chinese patent application No. 2024214246307, filed on June 20, 2024, with the Chinese Patent Office, the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of battery, in particular to a power battery system pressure relief assembly. BACKGROUND

[0003] The current power battery system, the pressure relief channel of the pressure relief system is composed of the cavity of the aluminum profile box and the bottom guard plate. After the thermal runaway of the battery cell, the thermal runaway material passes through the pressure relief cavity and is finally discharged to the external environment through the explosion-proof valve installed on the aluminum profile box. When there are many battery cells, the pressure relief valves of all battery cells are generally arranged in the same direction, and then a pressure relief cavity is arranged in this direction to provide a channel for discharging thermal runaway materials for the battery cells that may have thermal runaway. TECHNICAL PROBLEM

[0004] When there are many battery cells, the length of the corresponding pressure relief cavity will become longer. When the conventional pressure relief cavity discharges thermal runaway materials, it will cause certain thermal influence on the battery cells flowing through, and cannot well control the spread of heat. TECHNICAL SOLUTION

[0005] The present application provides a power battery system pressure relief assembly for a power battery system, comprising:

[0006] A flow guide pipe having a flow collecting section and a flow converging section, the flow collecting section having a first port and a second port, the first port being in communication with a battery module of the power battery system, and the second port being in communication with the flow converging section;

[0007] An explosion-proof valve, one end of which is in communication with the flow converging section, and the other end is in communication with the outside of the power battery system;

[0008] Wherein, the flow collecting section and the flow converging section both have a gap between them and the battery cells in the power battery system. ADVANTAGEOUS EFFECTS

[0009] The power battery system storage part is designed and assembled in the form of a battery module, the length of a pressure relief cavity in the battery module can be controlled, the heat spread problem is relieved to a certain extent, and more importantly, when thermal runaway occurs in the battery module, the thermal runaway substances flowing out of the battery module are sequentially collected by a current collecting section, a current collecting cavity, and an explosion-proof valve, and then discharged from the power battery system, since the flow guide pipe is independent of the battery module in which the battery cells are assembled, and a gap is left between the flow guide pipe and the battery cells in the power battery system, the influence of heat spread is greatly relieved. BRIEF DESCRIPTION OF DRAWINGS

[0010] Fig. 1 is an exploded structure schematic diagram of the present application;

[0011] Fig. 2 is a structure schematic diagram of the explosion-proof valve and the structure cover plate in a threaded connection state of the present application;

[0012] Fig. 3 is an A-A cross-sectional structure schematic diagram of Fig. 2 of the present application;

[0013] Fig. 4 is a first perspective structure schematic diagram of the explosion-proof valve and the structure cover plate in a threaded connection state of the present application;

[0014] Fig. 5 is a second perspective structure schematic diagram of the explosion-proof valve and the structure cover plate in a threaded connection state of the present application;

[0015] Fig. 6 is a structure schematic diagram of the structure cover plate in a flange plate and shell connection state of the present application;

[0016] Fig. 7 is a B-B cross-sectional structure schematic diagram of Fig. 6 of the present application.

[0017] Fig. 8 is a first perspective structure schematic diagram of the structure cover plate in a flange plate and shell connection state of the present application;

[0018] Fig. 9 is a second perspective structure schematic diagram of the structure cover plate in a flange plate and shell connection state of the present application;

[0019] Wherein, the meaning of the reference signs is as follows: 11, current collecting section; 12, current collecting cavity; 2, explosion-proof valve; 21, extension pipe; 3, structure cover plate; 31, pressure relief pipe; 32, flange plate; 33, threaded hole; 34, limiting protrusion; 4, battery module; 41, battery cell; 42, pressure relief valve; 43, pressure relief cavity; 5, shell; 51, assembly hole; 6, sealing structure; 7, current collecting cavity; 8, sealing strip; 81, avoiding hole; 9, U-shaped pipe. Embodiment of the present application

[0020] In the description of the present application, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terminology used in the specification of the present application is only for the purpose of describing specific embodiments and is not intended to limit the present application.

[0022] Referring to FIGS. 1-5, the present application discloses a power battery system pressure relief assembly for a power battery system, comprising a flow guide pipe and an explosion-proof valve 2, the flow guide pipe having a current collecting section 11 and a current collecting section 12, the current collecting section 11 having a first port and a second port, the first port being in communication with a battery module 4 of the power battery system, the second port being in communication with the current collecting section 12, the explosion-proof valve 2 being in communication with the current collecting section 12 at one end and being communicated to the outside of the power battery system at the other end, wherein the current collecting section 11 and the current collecting section 12 both have a gap between the battery cell in the power battery system.

[0023] Specifically, the flow guide pipe has a current collecting section 11 and a current collecting section 12, wherein the current collecting section 11 is used to collect the thermal runaway substances that may be generated in the battery module 4 that it is in communication with, and the current collecting section 12 is used to combine the thermal runaway substances collected by the current collecting section 11 and discharge the thermal runaway substances from the explosion-proof valve 2. The two ends of the current collecting section 11 are a first port and a second port, respectively, the first port is in communication with the battery module 4 of the power battery system, used to collect the thermal runaway substances generated in the battery module 4, and the second port is in communication with the current collecting section 12, used to transmit the collected thermal runaway substances to the current collecting section 12.

[0024] The working principle of the above structure is:

[0025] When the battery module 4 appears thermal runaway, the thermal runaway substance in the battery module 4 will flow from the first port of the current collecting section 11 to the second port, and then flow out of the power battery system through the current collecting section 12 and the explosion-proof valve 2. Compared with the prior art, when the thermal runaway substance generated by the battery module 4 flows in the pressure relief cavity 43, it will affect the adjacent other battery modules 4. After the battery module 4 appears thermal runaway, the above structure directly flows into the flow guide pipe (current collecting section 11 and current collecting section 12) through the inside of the battery module 4. Since there is a gap between the flow guide pipe and the battery module 4, the thermal runaway substance directly flows into the flow guide pipe and then separates from the contact with the battery module 4, greatly reducing the risk and degree of thermal spread and improving the safety performance of the power battery system.

[0026] Referring to FIG. 3, in some embodiments, in order to adapt to the requirement of placing the battery cell 41 horizontally in part of the power battery system, the battery module 4 is provided with the battery cell 41 and the pressure relief cavity 43. The large surface of the battery cell 41 is arranged horizontally. The battery cell 41 is provided with a pressure relief valve 42. The pressure relief valve 42 is in communication with the pressure relief cavity 43. The first port is in communication with the pressure relief cavity 43.

[0027] Specifically, when the large surface of the battery cell 41 is arranged horizontally, i.e. when the battery cell 41 is placed horizontally, the conventional pressure relief cavity 43 structure cannot achieve pressure relief. The above structure adopts the combination of the pressure relief cavity 43 and the flow guide pipe, which can discharge the thermal runaway substance leaked into the pressure relief cavity 43 by the pressure relief valve 42 when the battery cell 41 is placed horizontally, thereby reducing the risk of thermal spread of the power battery system.

[0028] By adopting the above scheme, when the large surface of the battery cell 41 is arranged horizontally, i.e. when the battery cell 41 is placed horizontally, the conventional pressure relief cavity structure cannot achieve pressure relief on the basis of the structure. When the battery cell 41 appears thermal runaway, the high-temperature and high-pressure substance is directly discharged into the current collecting section through the short pressure relief cavity 43, and then discharged from the power battery system through the current collecting section and the explosion-proof valve, thereby greatly reducing the risk of thermal spread of the power battery system.

[0029] Referring to FIGS. 1-3, in some embodiments, when the power battery system is provided with more than one battery module 4, i.e. the power battery system is provided with N battery modules 4 (N≥1), the current collecting section 11 is provided with N, wherein each first port is in one-to-one correspondence with each battery module 4, at least one second port is in communication with the current collecting section 12, and the other second ports are directly / indirectly in communication with the current collecting section 12.

[0030] Specifically, when the power battery system is provided with N battery modules 4, the corresponding current collecting section 11 is provided with N current collecting sections, and the first port of the N current collecting sections 11 is in one-to-one correspondence with the pressure relief cavity 43 of the N battery modules 4, and at least one second port of the N current collecting sections 11 is in communication with the current collecting section 12, and the remaining second ports can be directly in communication with the current collecting section 12, that is, the second port is directly in communication with the current collecting section 12, and the current collecting section 12 is in communication with the second port of all the current collecting sections 11.

[0031] By adopting the above scheme, when the power battery system is provided with N battery modules, N current collecting sections are correspondingly provided, wherein the first port of each current collecting section is installed corresponding to one of the battery modules, for preparing to collect the thermal runaway substances that can be generated in each battery module, and the second port of the N current collecting sections can be connected in a mode selected according to requirements, which can be directly connected with the current collecting section, or at least one second port of the N current collecting sections is in communication with the current collecting section, and the second port of the other current collecting sections that are not directly connected with the current collecting section is connected to the adjacent current collecting section to indirectly communicate with the current collecting section.

[0032] Of course, according to requirements, a check valve or the like can be arranged at the opening to prevent the adjacent thermal runaway substances from flowing into other battery modules 4 during the flow process to the explosion-proof valve 2.

[0033] Referring to FIGS. 1-2, in some embodiments, the power battery system is also provided with N battery modules 4, and the current collecting section 11 is provided with N current collecting sections, wherein each first port is in one-to-one correspondence with each battery module 4, and an opening is arranged between the first port and the second port of the current collecting section 11, and the second port of the current collecting section 11 close to the current collecting section 12 is in communication with the current collecting section 12 in the direction of the current collecting section 12, and the remaining second ports are sequentially connected with the openings on the adjacent current collecting sections 11.

[0034] Specifically, the first port of each current collecting section 11 is installed corresponding to one of the battery modules 4, for preparing to collect the thermal runaway substances that can be generated in each battery module 4, and an opening is arranged between the first port and the second port of the current collecting section 11, which is used to communicate with the adjacent second port to realize the sequential connection of the current collecting sections 11, facilitate the design of the flow guide pipe, and reduce the occupied volume of the pressure relief assembly in the power battery system.

[0035] In some embodiments, the explosion-proof valve 2 is directly connected with the current collecting section 12, and the current collecting section 11 is used to connect the pressure relief cavities 43 between the adjacent two battery modules 4, so as to realize the collection and discharge of the thermal runaway substances in the case of multiple battery modules 4.

[0036] In some embodiments, the collecting section 12 in the flow guide pipe is the main pipe, and the collecting section 11 is the branch pipe. One end of all the branch pipes is in communication with the pressure relief cavity 43 of the battery module 4, and the other end is in communication with the main pipe. The above structure forms a reliable pressure relief pipe 31 with a simple pipe network structure. Similarly, the designer can set a check valve at the branch pipe according to the use requirement to prevent the thermal runaway substance from flowing into other normal battery modules 4.

[0037] Referring to FIG. 1, in some embodiments, in order to facilitate the installation of the pressure relief valve 42, the shell 5 of the power battery system is provided with an assembly hole 51, and the explosion-proof valve 2 is installed at the assembly hole 51. The assembly hole 51 facilitates the installation of the explosion-proof valve 2, and the explosion-proof valve 2 facilitates the communication between the inside and outside of the power battery system. In addition, a structure for fixing the explosion-proof valve 2, such as a buckle, a threaded hole 33, etc., can be arranged at the assembly hole 51. In some embodiments, a threaded hole is arranged at the assembly hole 51 of the shell 5, and the explosion-proof valve 2 is provided with a threaded hole corresponding in number and position to the threaded hole. The explosion-proof valve 2 is fixed to the shell 5 by means of a bolt passing through the threaded hole arranged at the assembly hole 51 and the threaded hole arranged on the explosion-proof valve 2.

[0038] Referring to FIGS. 1-5, in some embodiments, in order to improve the sealing performance of the connection between the explosion-proof valve 2 and the assembly hole 51, a sealing structure 6 is arranged at the connection between the explosion-proof valve 2 and the assembly hole 51. The sealing structure 6 can ensure the sealing performance of the explosion-proof valve 2 and the assembly hole 51, and prevent the thermal runaway substance from escaping from the joint between the explosion-proof valve 2 and the assembly hole 51.

[0039] Referring to FIGS. 1-5, specifically, the sealing structure 6 can be a sealing ring, a sealing strip 8, or a sealing glue, etc., which can strengthen the airtightness of the explosion-proof valve 2 and the assembly hole 51. In some embodiments, the sealing structure 6 adopts a sealing ring, which is sleeved on the side of the explosion-proof valve 2 facing the shell 5. When the explosion-proof valve 2 is assembled, the sealing ring seals the joint between the explosion-proof valve 2 and the assembly hole 51, thereby improving the sealing performance of the explosion-proof valve 2 and the assembly hole 51.

[0040] Referring to FIGS. 1-5, in some embodiments, in order to facilitate the connection between the explosion-proof valve 2 and the collecting section 12, a structure cover plate 3 is arranged between the explosion-proof valve 2 and the collecting section 12. The structure cover plate 3 is connected to the explosion-proof valve 2, and a collecting cavity 7 is formed between the structure cover plate 3 and the explosion-proof valve 2. The collecting cavity 7 is used for preliminarily collecting the thermal runaway substance discharged by the collecting section 12. The collecting section 12 is in communication with the collecting cavity 7 through the structure cover plate 3.

[0041] Referring to FIG. 1-5, in some embodiments, the structural cover plate 3 is provided with a pressure relief pipe 31, the pressure relief pipe 31 is communicated with the confluence section 12, and the pressure relief pipe 31 is communicated with the confluence cavity 7. Specifically, the structural cover plate 3 is provided with the pressure relief pipe 31 which is communicated with the confluence section 12, and the confluence section 12 and the pressure relief pipe 31 are communicated through the U-shaped pipe 9, which facilitates the assembly of the structural cover plate 3 and the pressure relief pipe 31. Of course, the confluence section 12 and the pressure relief pipe 31 can also be indirectly connected, for example, in some embodiments, the confluence section 12 is connected through the U-shaped pipe 9.

[0042] On the basis of the above structure, the structure of the explosion-proof valve 2 is mainly divided into two kinds:

[0043] One, referring to FIG. 1-5, the explosion-proof valve 2 is provided with an extension pipe 21, the shell 5 of the power battery system is provided with an assembly hole 51, the extension pipe 21 passes through the assembly hole 51, and the structural cover plate 3 is threadedly connected with the extension pipe 21. The above structure adopts the way of setting the extension pipe 21 on the explosion-proof valve 2, and the extension pipe 21 is threadedly connected with the structural cover plate 3 after passing through the assembly hole 51, which can make the confluence cavity 7 formed by the explosion-proof valve 2 and the structural cover plate 3 have better air tightness, and the assembly of the explosion-proof valve 2 and the structural cover plate 3 is also more convenient. The threadedly connected structural cover plate 3 and the extension pipe 21 can be provided with matching threads.

[0044] Two, referring to FIG. 6-9, the outer edge of the structural cover plate 3 extends to form a flange plate 32, and the structural cover plate 3 is fixedly connected with the shell 5 through the flange plate 32. The above structure greatly improves the air tightness of the connection between the structural cover plate 3 and the shell 5 by fixing the structural cover plate 3 and the shell 5 through the flange plate 32.

[0045] In some embodiments, in order to improve the air tightness of the connection between the structural cover plate 3 and the shell 5, a sealing strip 8 is arranged between the flange plate 32 and the shell 5, the sealing strip 8 is arranged along the coverage of the flange plate 32 on the shell 5, and the flange plate 32 is provided with a limiting protrusion 34 on the side facing the sealing strip 8. The limiting protrusion 34 can control the distance between the flange plate 32 and the shell 5, thereby controlling the compression amount of the sealing strip 8, and ensuring the air tightness and stability of the sealing strip 8.

[0046] In some embodiments, the flange 32 is bolted to the shell 5, the flange 32 is provided with bolt holes 33 through which the bolts pass, and the limiting protrusions 34 are arranged along the hole edge of the bolt holes 33, the sealing strip 8 is provided with avoiding holes 81 at the corresponding positions of the bolt holes 33, and the limiting protrusions 34 pass through the avoiding holes 81. The above structure can control the compression amount of the sealing strip 8 by arranging the limiting protrusions 34 on the flange 32 at the bolt holes 33, and the sealing strip 8 is correspondingly provided with the avoiding holes 81 for avoiding the limiting protrusions 34, and the limiting protrusions 34 abut against the shell 5 through the avoiding holes 81, so as to prevent the problem of excessive compression of the sealing strip 8, thereby improving the sealing performance and stability of the sealing strip 8. In addition, the cooperation of the avoiding holes 81 and the limiting protrusions 34 also facilitates the positioning and installation of the sealing strip 8.

[0047] Of course, the designer can also set the number and position of the bolt holes 33 according to the needs, and correspondingly set the number and position of the limiting protrusions 34 and the avoiding holes 81, so as to improve the stability of the contact between the limiting protrusions 34 and the shell 5.

[0048] In addition, the flow guide pipe in the present application can be provided with multiple pipes according to the needs, and the connection mode can adopt one of the above connection modes. In some embodiments, two flow guide pipes are provided to improve the flux per unit time, thereby improving the safety of the power battery system.

Claims

1. A pressure relief assembly for a power battery system, used in a power battery system, comprising: The guide pipe has a collecting section (11) and a converging section (12). The collecting section (11) has a first port and a second port. The first port is connected to the battery module (4) of the power battery system, and the second port is connected to the converging section (12). An explosion-proof valve (2) is provided, with one end connected to the busbar (12) and the other end connected to the outside of the power battery system. Both the current collecting section (11) and the current converging section (12) have gaps between them and the cells in the power battery system.

2. The pressure relief assembly for a power battery system according to claim 1, wherein, The battery module (4) is provided with a battery cell (41) and a pressure relief chamber (43). The large surface of the battery cell (41) is arranged horizontally. The battery cell (41) has a pressure relief valve (42). The pressure relief valve (42) is connected to the pressure relief chamber (43). The first port is connected to the pressure relief chamber (43).

3. A pressure relief assembly for a power battery system according to claim 1, wherein, The power battery system has N battery modules (4) and N current collection sections (11). Each first port is connected to each battery module (4) in a one-to-one correspondence, and the second port is connected to the current collection section (12).

4. A pressure relief assembly for a power battery system according to claim 1, wherein, The power battery system has N battery modules (4) and N current collection sections (11). Each first port is connected to each battery module (4) in a one-to-one correspondence. An opening is provided between the first port and the second port of the current collection section (11). In the direction towards the current collection section (12), the second port of the current collection section (11) closest to the current collection section (12) is connected to the current collection section (12), and the remaining second ports are connected to the openings on the adjacent current collection sections (11) in sequence.

5. A pressure relief assembly for a power battery system according to claim 1, wherein, The housing (5) of the power battery system is provided with an assembly hole (51), and the explosion-proof valve (2) is installed at the assembly hole (51).

6. A pressure relief assembly for a power battery system according to claim 5, wherein, The explosion-proof valve (2) is provided with a sealing structure (6) at the connection between it and the assembly hole (51).

7. A pressure relief assembly for a power battery system according to any one of claims 1-6, wherein, A structural cover plate (3) is provided between the explosion-proof valve (2) and the manifold (12). The structural cover plate (3) is connected to the explosion-proof valve (2). The structural cover plate (3) and the explosion-proof valve (2) form a manifold (7). The manifold (12) is connected to the manifold (7) through the structural cover plate (3).

8. A pressure relief assembly for a power battery system according to claim 7, wherein, The structural cover plate (3) is provided with a pressure relief pipe (31), one end of which is connected to the manifold section (12), and the other end of which is connected to the manifold cavity (7).

9. A pressure relief assembly for a power battery system according to claim 7, wherein, The explosion-proof valve (2) is provided with an extension tube (21), the outer shell (5) of the power battery system is provided with an assembly hole (51), the extension tube (21) is provided through the assembly hole (51), and the structural cover plate (3) is threadedly connected to the extension tube (21).

10. A pressure relief assembly for a power battery system according to claim 9, wherein, The outer edge of the structural cover plate (3) extends to form a flange (32), and the structural cover plate (3) is fixedly connected to the outer shell (5) through the flange (32).

11. A pressure relief assembly for a power battery system according to claim 10, wherein, A sealing strip (8) is provided between the flange (32) and the outer shell (5). The sealing strip (8) is provided along the flange (32) on the covering surface of the outer shell (5). A limiting protrusion (34) is provided on the side of the flange (32) facing the sealing strip (8).

12. A pressure relief assembly for a power battery system according to claim 11, wherein, The flange (32) is bolted to the housing (5). The flange (32) has a bolt hole (33) through which the bolt passes. The limiting protrusion (34) is provided along the edge of the bolt hole (33). The sealing strip (8) has a clearance hole (81) at the corresponding position of the bolt hole (33). The limiting protrusion (34) passes through the clearance hole (81).

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