Explosion-proof shell, battery cell and battery module

Abstract

The utility model relates to the technical field of energy storage equipment, in particular to an explosion-proof shell, a battery cell and a battery module, the explosion-proof shell comprises a shell body, an explosion-proof valve, a first cover plate, a positive electrode output end and a negative electrode output end, the first cover plate covers an opening at one end of the shell body along the length direction of the first cover plate in a sealing manner; the anti-explosion valve is arranged on the first side wall of one end of the shell body in the width direction of the shell body, the anti-explosion valve is close to the first side wall and is arranged away from the first end of the first cover plate in the length direction of the shell body, and the positive electrode output end and the negative electrode output end are both arranged on the first cover plate. The battery cell comprises a pole group and the explosion-proof shell, wherein the pole group is arranged in the explosion-proof shell. The battery module comprises a plurality of the battery cells, the plurality of battery cells are sequentially arranged in the thickness direction of the battery cells to form one row or multiple rows of battery cells, and the anti-explosion valve of any battery cell does not face any other battery cell. The explosion-proof shell, the battery cell and the battery module can prevent thermal runaway from spreading, and the safety is improved.

Description

Technical Field

[0001] This utility model relates to the field of energy storage equipment technology, and in particular to an explosion-proof housing, a battery cell, and a battery module. Background Technology

[0002] To improve the safety performance of battery cells, pressure relief mechanisms such as explosion-proof valves are typically installed. When a battery cell malfunctions and the internal pressure becomes too high, the gas can be released through the pressure relief mechanism to prevent explosions or other major safety accidents. Currently, the explosion-proof valves of battery cells are all located on the cover plate, which also houses output components such as terminals for electrical connection. Furthermore, when multiple battery cells are arranged in a battery module, to shorten the length of the electrical connections between cells, the output components of adjacent cells are generally placed close together, meaning the cover plates of adjacent cells are placed close together. When a short circuit occurs inside the terminal group of a battery cell, the terminal group may ignite. As the internal temperature and pressure of the cell rise, the explosion-proof valve opens, and gas, electrolyte, and molten slag mixed with sparks are rapidly released from the valve. Because the output components of adjacent cells are placed close together, these components are exposed to high temperatures and sparks, causing the insulation of the output components to melt and fail, leading to short circuits in adjacent cells and triggering thermal runaway. If this situation spreads, it can cause serious safety accidents. Utility Model Content

[0003] One objective of this invention is to provide an explosion-proof housing that can prevent the spread of thermal runaway and improve the safety of the battery module.

[0004] To achieve this objective, the present invention adopts the following technical solution:

[0005] An explosion-proof housing is provided, comprising a housing body, an explosion-proof valve, a first cover plate, a positive output terminal, and a negative output terminal. The first cover plate is sealed over an opening at one end of the housing body along its length. The explosion-proof valve is disposed on a first sidewall at one end of the housing body along its width, and is located near the first sidewall at a first end along the length of the housing body away from the first cover plate. Both the positive output terminal and the negative output terminal are disposed on the first cover plate.

[0006] Optionally, the minimum distance 'a' between the edge of the explosion-proof valve and the edge of the first end satisfies that 'a' ≥ 10 mm.

[0007] Optionally, the maximum distance between the edge of the explosion-proof valve and the edge of the first end is b, and the dimension of the first sidewall along the length direction of the shell body is c, satisfying b < c / 2.

[0008] Optionally, at least two explosion-proof valves are provided, and the at least two explosion-proof valves are sequentially and spaced apart along the length of the shell body on the first side wall.

[0009] Optionally, the interval d between two adjacent explosion-proof valves satisfies the condition that d > 10 mm;

[0010] And / or, the maximum distance between the edge of the explosion-proof valve furthest from the first end and the edge of the first end in at least two of the explosion-proof valves is e, and the dimension of the first sidewall along the length direction of the shell body is c, satisfying e < c / 2.

[0011] Optionally, it also includes a side plate, which is disposed on the inner side of the first side wall, and the side plate has a plurality of vent holes, at least some of which are opened corresponding to the explosion-proof valve.

[0012] Optionally, the side plate has an exhaust groove at one end away from the first side wall, the exhaust groove extends along the length of the shell body, and the exhaust hole is opened at the bottom of the exhaust groove.

[0013] Optionally, the side plate has a first region and a second region, and a plurality of the exhaust holes are partially located in the first region and partially located in the second region. The first region corresponds to the explosion-proof valve, and the second region and the first region are symmetrically arranged along the length direction of the shell body.

[0014] Another objective of this invention is to provide a battery cell that can prevent the spread of thermal runaway and improve the safety of the battery module.

[0015] To achieve this objective, the present invention adopts the following technical solution:

[0016] A battery cell is provided, comprising an electrode assembly and the aforementioned explosion-proof housing, wherein the electrode assembly is disposed within the explosion-proof housing.

[0017] Another objective of this invention is to provide a battery module that can prevent the spread of thermal runaway and improve the safety of the battery module.

[0018] To achieve this objective, the present invention adopts the following technical solution:

[0019] A battery module is provided, comprising a plurality of the above-described battery cells, wherein the plurality of battery cells are arranged sequentially along their own thickness direction to form one or more rows of battery cells, wherein the explosion-proof valve of any battery cell does not face any other battery cell.

[0020] The beneficial effects of this utility model are:

[0021] This utility model provides an explosion-proof housing, including a housing body, an explosion-proof valve, a first cover plate, a positive output terminal, and a negative output terminal. The first cover plate is sealed over an opening at one end of the housing body along its length. The explosion-proof valve is disposed on a first sidewall at one end of the housing body along its width, and is located near the first end of the first sidewall away from the first cover plate along the length of the housing body. Both the positive and negative output terminals are located on the first cover plate. By placing the explosion-proof valve on the first sidewall, it can be positioned away from the positive and negative output terminals on the first cover plate to a certain extent. This allows the high-temperature mixture of sparks ejected from the thermally runaway battery cell to be kept away from the output terminals of adjacent battery cells during the explosion-proof valve rupture, preventing the spread of thermal runaway during the explosion-proof valve rupture and improving safety. Furthermore, placing the explosion-proof valve on the first sidewall away from the first cover plate further increases the distance between the explosion-proof valve and the two output terminals, further achieving thermoelectric separation and improving safety.

[0022] This utility model also provides a battery cell, including an electrode assembly and the aforementioned explosion-proof housing, with the electrode assembly disposed within the explosion-proof housing. This battery cell can prevent the propagation of thermal runaway and improve the safety of the battery module.

[0023] This utility model also provides a battery module comprising multiple cells as described above, arranged sequentially along their thickness direction to form one or more rows of cells, wherein the explosion-proof valve of any cell does not face any other cell. This battery module can prevent the spread of thermal runaway and improve the safety of the battery module. Attached Figure Description

[0024] Figure 1 This is a first-view structural schematic diagram of the explosion-proof housing provided in this embodiment of the present invention;

[0025] Figure 2 This is a second-view structural schematic diagram of the explosion-proof housing provided in this embodiment of the present invention;

[0026] Figure 3 This is a third-view structural schematic diagram of the explosion-proof housing (with an explosion-proof valve) provided in this embodiment of the utility model;

[0027] Figure 4 This is a third-view structural schematic diagram of the explosion-proof housing (with two explosion-proof valves) provided in this embodiment of the present invention;

[0028] Figure 5 This is an exploded view of the battery cell provided in an embodiment of this utility model.

[0029] In the picture:

[0030] 1. Shell body; 11. First sidewall; 111. First end;

[0031] 2. Explosion-proof valve; 3. First cover plate; 4. Positive output terminal; 5. Negative output terminal;

[0032] 6. Side panel; 61. Exhaust vent; 601. First area; 602. Second area;

[0033] 7. Second cover plate; 8. Injection hole plug; 9. Injection hole cover;

[0034] 100. Explosion-proof housing; 200. Electrode assembly; 300. First insulating patch; 400. Second insulating patch; 500. Outer insulating film; 600. Inner insulating film. Detailed Implementation

[0035] The technical solution of this utility model will be further described below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for explaining this utility model and not for limiting it. Furthermore, it should be noted that, for ease of description, only the parts related to this utility model are shown in the drawings, not all of them.

[0036] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0037] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0038] To improve the safety performance of battery cells, pressure relief mechanisms such as explosion-proof valves are typically installed. When a battery cell malfunctions and the internal pressure becomes too high, the gas can be released through the pressure relief mechanism to prevent explosions or other major safety accidents. Currently, the explosion-proof valves of battery cells are all located on the cover plate, which also houses output components such as terminals for electrical connection. Furthermore, when multiple battery cells are arranged in a battery module, to shorten the length of the electrical connections between cells, the output components of adjacent cells are generally placed close together, meaning the cover plates of adjacent cells are placed close together. When a short circuit occurs inside the terminal group of a battery cell, the terminal group may ignite. As the internal temperature and pressure of the cell rise, the explosion-proof valve opens, and gas, electrolyte, and molten slag mixed with sparks are rapidly released from the valve. Because the output components of adjacent cells are placed close together, these components are exposed to high temperatures and sparks, causing the insulation of the output components to melt and fail, leading to short circuits in adjacent cells and triggering thermal runaway. If this situation spreads, it can cause serious safety accidents.

[0039] Therefore, this embodiment provides an explosion-proof housing 100 to solve the above-mentioned problems. The explosion-proof housing 100 can prevent the spread of thermal runaway and improve the safety of the battery module.

[0040] like Figures 1-3 As shown, the explosion-proof housing 100 of this embodiment includes a housing body 1, an explosion-proof valve 2, a first cover plate 3, a positive output terminal 4, and a negative output terminal 5. The first cover plate 3 is sealed and covered at the opening at one end of the housing body 1 along its own length direction. The explosion-proof valve 2 is disposed on the first side wall 11 at one end of the housing body 1 along its own width direction, and the explosion-proof valve 2 is disposed near the first end 111 of the first side wall 11 along the length direction of the housing body 1 away from the first cover plate 3. The positive output terminal 4 and the negative output terminal 5 are both disposed on the first cover plate 3.

[0041] By placing the explosion-proof valve 2 on the first sidewall 11, it can be positioned to a certain extent away from the positive output terminal 4 and the negative output terminal 5 on the first cover plate 3. This allows the high-temperature mixture of hot sparks ejected from the thermally runaway battery cell to be kept away from the electrical output terminals of adjacent cells during the explosion of the explosion-proof valve 2, preventing the spread of thermal runaway and improving the safety of the battery module. Furthermore, placing the explosion-proof valve 2 on the first sidewall 11, away from the first end 111 of the first cover plate 3, further increases the distance between the explosion-proof valve 2 and the two output terminals, further achieving thermal-electric separation and improving safety. The first sidewall 11 has a smaller area than the two adjacent sidewalls and is less prone to deformation; therefore, the explosion-proof valve 2 is placed on the first sidewall 11.

[0042] Optionally, the explosion-proof housing 100 further includes a second cover plate 7, which is sealed at the opening at the other end of the housing body 1 along its own length direction. That is, the second cover plate 7 is arranged opposite to the first cover plate 3, and the housing body 1, the first cover plate 3 and the second cover plate 7 together form a sealed battery cell housing.

[0043] like Figure 3 As shown, optionally, the minimum distance 'a' between the edge of the explosion-proof valve 2 and the edge of the first end 111 satisfies the condition that 'a' ≥ 10 mm, meaning that the edge of the explosion-proof valve 2 near the first end 111 is at least 10 mm away from the edge of the first end 111. An explosion-proof hole needs to be opened on the first sidewall 11, and the sealing cap of the explosion-proof valve 2 is used to seal the explosion-proof hole. If the explosion-proof hole is too close to the first end 111 of the first sidewall 11, it will be difficult to position during punching, and it will easily cause deformation of the opening at the first end 111, affecting the sealing connection between the shell body 1 and the second cover plate 7.

[0044] Optionally, the maximum distance between the edge of the explosion-proof valve 2 and the edge of the first end 111 is b, and the dimension of the first sidewall 11 along the length of the shell body 1 is c, satisfying b < c / 2. That is, the maximum distance between the edge of the explosion-proof valve 2 away from the edge of the first end 111 and the edge of the first end 111 cannot exceed half the length of the first sidewall 11, meaning the explosion-proof valve 2 must be located in this half-area of ​​the first sidewall 11 with the first end 111. The above limitation can further ensure that the distance between the explosion-proof valve 2 and the first cover plate 3 is sufficient, and can ensure the effectiveness of electrothermal separation.

[0045] Optionally, as the cell length increases, to ensure the effectiveness of explosion protection and avoid excessively long venting paths that could lead to delayed explosion protection, more than one explosion-proof valve 2 can be installed. Optionally, when the cell length is in the range of 200mm-400mm, generally one explosion-proof valve 2 is sufficient. Figure 1 and Figure 3 As shown. When the length of the battery cell is in the range of 400mm-600mm, one or two explosion-proof valves are generally installed.

[0046] like Figure 4 As shown, at least two explosion-proof valves 2 are provided, and at least two explosion-proof valves 2 are arranged sequentially and at intervals along the length direction of the shell body 1 on the first side wall 11.

[0047] Optionally, the interval d between two adjacent explosion-proof valves 2 shall satisfy that d > 10 mm. If the interval between two adjacent explosion-proof valves 2 is too close, i.e. less than 10 mm, it is easy to cause collapse and deformation when punching explosion-proof holes, which will affect the assembly of explosion-proof valves 2 and the insertion of electrode assembly 200 into the shell, resulting in poor process. Therefore, it is necessary to limit the interval between two adjacent explosion-proof valves 2 to be greater than 10 mm.

[0048] Optionally, the maximum distance between the edge of the explosion-proof valve 2 furthest from the first end 111 and the edge of the first end 111 is e, and the dimension of the first sidewall 11 along the length of the shell body 1 is c, satisfying e < c / 2. That is, at least two explosion-proof valves 2 need to be located in the half-region of the first sidewall 11 with the first end 111, to ensure that the explosion-proof valve 2 closest to the first cover plate 3 is also at least half the length of the shell body 1 away from the first cover plate 3, thereby ensuring the effectiveness of thermoelectric separation.

[0049] like Figure 5 As shown, optionally, the explosion-proof housing 100 also includes a side plate 6, which is used to support the electrode assembly 200. The side plate 6 is disposed on the inner side of the first side wall 11. The side plate 6 has a plurality of exhaust holes 61, at least some of which are opened to correspond to the explosion-proof valve 2, so as to ensure that the side plate 6 will not block the explosion-proof holes, thereby ensuring normal exhaust in the event of thermal runaway.

[0050] Optionally, an exhaust groove is formed on the end face of the side plate 6 opposite to the first side wall 11. The exhaust groove extends along the length of the shell body 1, and the exhaust hole 61 is formed at the bottom of the exhaust groove. The gas flow cross section is larger at the exhaust groove, the gas is discharged faster, and the pressure is lower, which can help to safely and quickly exhaust the gas. Optionally, multiple exhaust grooves can be formed parallel to each other along the width direction of the first side wall 11, and some exhaust holes 61 correspond to one exhaust groove, while other exhaust holes 61 correspond to other exhaust grooves.

[0051] Optionally, the side plate 6 has a first region 601 and a second region 602. A plurality of vent holes 61 are partially located in the first region 601 and partially in the second region 602. The first region 601 corresponds to the explosion-proof valve 2, and the second region 602 and the first region 601 are symmetrically arranged along the length of the shell body 1. This symmetrical arrangement prevents the side plate 6 from being assembled in reverse and simplifies the assembly process.

[0052] Optionally, the explosion-proof housing 100 further includes an injection hole plug 8 and an injection hole cover 9. Optionally, in this embodiment, the injection hole is opened on the first cover plate 3, the injection hole plug 8 is used to block the injection hole, and the injection hole cover 9 is placed on the outside of the injection hole plug 8 to perform secondary sealing of the injection hole.

[0053] This embodiment also provides a battery cell, including a pole group 200 and the aforementioned explosion-proof housing 100, with the pole group 200 disposed within the explosion-proof housing 100. Optionally, the battery cell further includes a first insulating patch 300 attached to the outside of the first cover plate 3, a second insulating patch 400 attached to the outside of the second cover plate 7, an outer insulating film 500 wrapped around the outside of the housing body 1, and an inner insulating film 600 wrapped around the outside of the pole group 200, to ensure insulation at all points and prevent short circuits. It should be noted that the first insulating patch 300 has through holes to allow the positive output terminal 4 and the negative output terminal 5 to be electrically connected to the outside.

[0054] The explosion-proof housing 100 of the battery cell places the explosion-proof valve 2 at a position far away from the output end, which can effectively ensure electrothermal separation, prevent the spread of thermal runaway, and improve the safety of the battery module.

[0055] This embodiment also provides a battery module, including a module housing and multiple battery cells as described above, all of which are disposed within the module housing. In this embodiment, a battery module contains multiple battery cells arranged sequentially along its thickness direction, forming a row of cells or multiple rows of cells in groups, which can be selected according to the size of the cells and the size of the battery module. Taking the first sidewall 11 located at the bottom as an example, thermal runaway of a battery cell will cause the high-temperature mixture to be discharged vertically downwards, and the first cover plate 3 located on one side will not be significantly affected, thus preventing short circuits between adjacent cells and facilitating the prevention of thermal runaway within the battery module, thereby ensuring the safety performance of the battery module. Furthermore, the explosion-proof valve 2 of any cell is not oriented towards any other cell. Taking multiple rows of cells as an example, when multiple rows of cells are located at the same height, the explosion-proof valves 2 are all oriented vertically upwards or downwards, or the explosion-proof valves 2 of the row of cells on the left are all oriented to the left, and the explosion-proof valves 2 of the row of cells on the right are all oriented to the right. Of course, the examples above are only to make the limitations clearer, and there are other ways to arrange things besides the examples.

[0056] The explosion-proof housing 100 of the battery module's cells places the explosion-proof valve 2 at a position far from the output end, which can effectively ensure the electrothermal separation of the cells, prevent the spread of thermal runaway, and improve the safety of the battery module.

[0057] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. An explosion-proof housing, characterized in that, The device includes a shell body (1), an explosion-proof valve (2), a first cover plate (3), a positive output terminal (4), and a negative output terminal (5). The first cover plate (3) is sealed over the opening at one end of the shell body (1) along its length. The explosion-proof valve (2) is disposed on the first side wall (11) at one end of the shell body (1) along its width. The explosion-proof valve (2) is disposed near the first side wall (11) at the first end (111) of the shell body (1) away from the first cover plate (3) along its length. The positive output terminal (4) and the negative output terminal (5) are both disposed on the first cover plate (3).

2. The explosion-proof housing according to claim 1, characterized in that, The minimum distance a between the edge of the explosion-proof valve (2) and the edge of the first end (111) satisfies that a ≥ 10 mm.

3. The explosion-proof housing according to claim 1, characterized in that, The maximum distance between the edge of the explosion-proof valve (2) and the edge of the first end (111) is b, and the dimension of the first sidewall (11) along the length direction of the shell body (1) is c, satisfying b < c / 2.

4. The explosion-proof housing according to claim 1, characterized in that, At least two explosion-proof valves (2) are provided, and at least two explosion-proof valves (2) are arranged sequentially at intervals along the length direction of the shell body (1) on the first side wall (11).

5. The explosion-proof housing according to claim 4, characterized in that, The interval d between two adjacent explosion-proof valves (2) satisfies that d > 10 mm; And / or, the maximum distance between the edge of the explosion-proof valve (2) furthest from the first end (111) and the edge of the first end (111) is e, and the dimension of the first sidewall (11) along the length direction of the shell body (1) is c, satisfying e < c / 2.

6. The explosion-proof enclosure according to any one of claims 1-5, characterized in that, It also includes a side plate (6), which is disposed on the inner side of the first side wall (11). The side plate (6) has a plurality of exhaust holes (61), at least some of which are opened corresponding to the explosion-proof valve (2).

7. The explosion-proof housing according to claim 6, characterized in that, The side plate (6) has an exhaust groove at one end away from the first side wall (11). The exhaust groove extends along the length of the shell body (1), and the exhaust hole (61) is opened at the bottom of the exhaust groove.

8. The explosion-proof housing according to claim 6, characterized in that, The side plate (6) has a first region (601) and a second region (602). A plurality of exhaust holes (61) are partially located in the first region (601) and partially located in the second region (602). The first region (601) corresponds to the explosion-proof valve (2). The second region (602) and the first region (601) are symmetrically arranged along the length direction of the shell body (1).

9. A battery cell, characterized in that, It includes a pole assembly (200) and an explosion-proof housing as described in any one of claims 1-8, wherein the pole assembly (200) is disposed within the explosion-proof housing (100).

10. A battery module, characterized in that, It includes multiple battery cells as described in claim 9, the multiple battery cells are arranged sequentially along their own thickness direction to form one or more rows of battery cells, and the explosion-proof valve (2) of any battery cell does not face any other battery cell.

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