Battery cell

Abstract

The utility model relates to the technical field of batteries, in particular to a battery cell, which comprises a battery cell pole group, the end plate assembly is arranged at the end part of the battery cell pole group; the anti-explosion valve is arranged on the end plate assembly; the end plate assembly is provided with a mounting part, and the limiting assembly is arranged on the mounting part; the limiting assembly is arranged between the anti-explosion valve and the battery cell pole group; and the limiting assembly can limit the distance between the battery cell pole group and the anti-explosion valve. According to the battery cell provided by the invention, when the battery cell triggers thermal runaway, the positions of the battery cell pole groups and the anti-explosion valves arranged on the battery cell pole groups relative to the end plates can be effectively limited, so that the battery cell pole groups are prevented from shielding the anti-explosion valves, the exhaust and heat dissipation effects of the anti-explosion valves are effectively improved, the temperature rise speed of the battery cell due to thermal runaway can be effectively delayed, and the peak temperature is reduced; the passing rate of the thermal runaway test of the battery cell is greatly improved, and the safety performance of the battery cell and even the whole PACK pack is improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell. Background Art

[0002] At present, the existing technology usually has an electrode group insulation protection structure inside the battery cell to prevent abnormal lap short circuit inside the battery cell. However, when the battery cell has thermal runaway, the internal temperature can reach above 600°C in a short period of time, and the internal plastic materials such as the side panels, bare battery cell insulation sheets, end panels, and lower plastic contained in the insulation protection structure of the unit will quickly melt and fail. At this time, under the action of high temperature and high pressure gas inside the shell, the electrode group is easy to lose balance. Because the pressure at the explosion-proof valve of the positive cover is low, the electrode group is easy to move toward the explosion-proof valve, thereby blocking the explosion-proof valve, causing the battery to fail to release pressure in time and catch fire and explode. Utility Model Content

[0003] The purpose of the present application is to provide a battery cell, so as to solve to a certain extent the technical problem in the prior art that the explosion-proof valve is easily blocked when the pole group inside the battery cell undergoes thermal runaway.

[0004] The present application provides a battery cell, comprising: a battery cell electrode group;

[0005] An end plate assembly, the end plate assembly being arranged at the end of the battery cell electrode group;

[0006] An explosion-proof valve, the explosion-proof valve being arranged on the end plate assembly;

[0007] A limiting assembly, wherein the end plate assembly is provided with a mounting portion, and the limiting assembly is arranged on the mounting portion; the limiting assembly is arranged between the explosion-proof valve and the battery cell pole group; the limiting assembly can limit the distance between the battery cell pole group and the explosion-proof valve.

[0008] In the above technical solution, further, the limit assembly includes a first limit member and a second limit member, and the first limit member and the second limit member are both arranged on the mounting portion; the first limit member is connected to the end plate assembly, and the second limit member is connected to the first limit member.

[0009] In any of the above technical solutions, further, an end plate plastic part, the end plate plastic part is arranged facing the battery cell electrode group, and the end plate plastic part is provided with the mounting portion;

[0010] The cover plate, the end plate plastic part is arranged on the cover plate, and the cover plate is located on a side of the end plate plastic part away from the battery cell electrode group; the explosion-proof valve is arranged on the cover plate.

[0011] In any of the above technical solutions, further, the first limiting member has a flat plate structure, the mounting portion has a groove structure or a cylinder structure, a first accommodating portion is formed at the opening of the mounting portion, the shape of the first accommodating portion is adapted to the shape of the first limiting member, and the first limiting member is embedded in the first accommodating portion.

[0012] In any of the above technical solutions, further, a supporting plate is arranged inside the mounting portion, a second accommodating portion is formed on one side of the supporting plate, and the second accommodating portion is connected to the first accommodating portion; the second limiting member is arranged in the second accommodating portion.

[0013] In any of the above technical solutions, further, the second limiting member includes a connecting portion and a stopping portion connected to the connecting portion; the connecting portion has a tube structure, and a hollow heat dissipation channel is formed inside the tube structure.

[0014] The stopper has a flat plate structure, one end of the connecting portion is connected to the stopper, and the other end of the stopper is connected to the first limiting member.

[0015] In any of the above technical solutions, further, the supporting plate is formed with a hole portion, and the hole portion is connected to the heat dissipation channel;

[0016] The battery core further includes a supporting protrusion, which is disposed in the second accommodating portion and extends toward the first limiting member to support the first limiting member.

[0017] In any of the above technical solutions, further, the first limiting member is provided with a through hole for penetrating the connecting portion, and when the connecting portion is penetrated in the through hole, an end of the connecting portion protrudes relative to the through hole to form a riveted portion.

[0018] In any of the above technical solutions, further, the support plate is provided with a through hole, and the number of the through hole is at least one;

[0019] The stopper is provided with notches, the number of the notches is the same as the number of the through openings, and each of the notches is arranged opposite to one of the through openings.

[0020] In any of the above technical solutions, further, among the first limiting member and the second limiting member, at least the stop portion of the second limiting member is made of aluminum alloy.

[0021] Compared with the prior art, the beneficial effects of this application are:

[0022] The battery cell provided in the present application includes: a battery cell pole group; an end plate assembly, which is arranged at the end of the battery cell pole group; an explosion-proof valve, which is arranged on the end plate assembly; a limiting assembly, the end plate assembly is provided with a mounting portion, and the limiting assembly is arranged on the mounting portion; the limiting assembly is arranged between the explosion-proof valve and the battery cell pole group; the limiting assembly can limit the distance between the battery cell pole group and the explosion-proof valve.

[0023] The battery cell provided in the present application can effectively limit the position of the battery cell pole group and the explosion-proof valve arranged on the battery cell pole group relative to the end plate when the battery cell triggers thermal runaway, so as to avoid the battery cell pole group blocking the explosion-proof valve, effectively improve the exhaust and heat dissipation effect of the explosion-proof valve, and can effectively delay the speed of temperature rise of the battery cell due to thermal runaway, reduce the peak temperature, greatly improve the pass rate of the battery cell thermal runaway test, and improve the safety performance of the battery cell and even the entire PACK package. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 A schematic diagram of the structure of a battery cell provided in an embodiment of the present application;

[0026] Figure 2 Another schematic diagram of the structure of the battery cell provided in the embodiment of the present application;

[0027] Figure 3 Another schematic diagram of the structure of the battery cell provided in the embodiment of the present application;

[0028] Figure 4 A schematic diagram of a battery cell provided in an embodiment of the present application from another perspective;

[0029] Figure 5 for Figure 4 Section view along AA.

[0030] Reference numerals:

[0031] 1-cover plate, 2-end plate plastic part, 3-installing part, 301-hole part, 302-first accommodating part, 303-second accommodating part, 4-first limiting member, 401-through hole, 5-second limiting member, 501-connecting part, 5011-heat dissipation channel, 502-stopping part, 5021-notch, 503-riveted part, 6-supporting protrusion, 7-through opening, 8-supporting plate. DETAILED DESCRIPTION

[0032] The technical solution of the present application will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0033] The components of the embodiments of the present application generally described and shown in the accompanying drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the application claimed, but merely represents the selected embodiments of the present application.

[0034] Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of this application.

[0035] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are 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, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0036] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0037] Refer to the following Figures 1 to 5 A battery cell according to an embodiment of the present application is described.

[0038] See also Figures 1 to 5As shown, an embodiment of the present application provides a battery cell, which includes an end plate assembly, a limit assembly and a battery cell pole group, wherein the end plate assembly is provided with a mounting portion 3, the limit assembly is arranged on the mounting portion 3, and an explosion-proof valve is arranged on the end plate assembly. When the battery cell pole group undergoes thermal runaway and generates high-temperature and high-pressure gas with increased temperature and a certain pressure, the high-temperature and high-pressure gas can reopen the explosion-proof valve to release the temperature and pressure of the battery cell pole group to avoid serious situations such as fire and explosion. One side surface of the end plate assembly faces the end plate of the battery cell pole group, the explosion-proof valve is arranged on the side surface of the end plate assembly away from the battery cell pole group, and the limit assembly is located between the battery cell pole group and the explosion-proof valve. When thermal runaway occurs in the battery cell pole group, the high-temperature and high-pressure gas acts on the end plate assembly, which may cause partial or complete deformation or even melting of the end plate assembly, resulting in loss of support between the end plate assembly and the battery cell pole group. At this time, due to the presence of the limit assembly, the limit assembly can limit the movement of the battery cell pole group toward the explosion-proof valve on the end plate assembly, thereby avoiding the battery cell pole group blocking or blocking the explosion-proof valve, affecting temperature and pressure relief.

[0039] Specifically, the end plate assembly includes a cover plate 1 and an end plate plastic part 2. The battery cell also includes a shell for encapsulating the battery cell pole group. The end plate assembly is arranged at the end of the shell. The cover plate 1 encapsulates the end plate plastic part 2 into the shell. The above-mentioned explosion-proof valve is arranged on the cover plate 1. It should be noted that both ends of the shell have openings, and at least one of the openings at both ends of the shell is provided with a cover plate 1.

[0040] In this embodiment, the end plate plastic part 2 is a long strip-shaped part made of plastic material, and is used to support the cell pole group. The end plate plastic part 2 is arranged on the end surface of the cell pole group. A mounting portion 3 is formed partially on one side of the end plate plastic part 2 facing the cell pole group. The mounting portion 3 has a groove structure or a cylinder structure, and the axial direction of the mounting portion 3 extends toward the thickness direction of the end plate plastic part 2. The limit assembly is arranged on the mounting portion 3, and the limit assembly and the mounting portion 3 are mutually adapted and connected, and the connection method can be but is not limited to a snap connection.

[0041] Furthermore, the limiting assembly includes a first limiting member 4 and a second limiting member 5, the first limiting member 4 has a flat plate structure, the mounting portion 3 includes a first accommodating portion 302 and a second accommodating portion 303 which are interconnected, the first accommodating portion 302 and the second accommodating portion 303 are distributed in a T-shape, the mounting portion 3 has a cylindrical structure, and a supporting plate 8 is arranged inside the cylindrical structure, the first accommodating portion 302 is arranged on a side surface of the end plate plastic part 2 facing the cover plate 1 and is located at the opening of the cylindrical structure of the mounting portion 3, the shape of the first accommodating portion 302 is adapted to the shape of the first limiting member 4, so that the first limiting member 4 can be embedded in the first accommodating portion 302, and the second accommodating portion 303 is formed in the space above the supporting plate 8.

[0042] The second limiting member 5 includes a connecting portion 501 and a stopping portion 502, both of which are arranged in the second accommodating portion 303, wherein the stopping portion 502 has a flat plate structure, and the stopping portion 502 is arranged on the supporting plate 8, the connecting portion 501 has a cylindrical structure, the axis of the connecting portion 501 is colinear or parallel to the axis of the mounting portion 3, one end of the connecting portion 501 is connected to the first limiting member 4, the stopping portion 502 has a flat plate structure, and the other end of the connecting portion 501 is connected to the stopping portion 502, the first limiting member 4 and the second limiting member 5 are in the shape of an "I" as a whole, and by limiting the stopping portion 502 of the first limiting member 4 and the second limiting member 5, it is possible to effectively avoid displacement, rotation, etc. of the limiting component, which affects the limiting and blocking effects on the battery cell pole group.

[0043] It should be noted that the interior of the tube structure of the connecting portion 501 is hollow, forming a heat dissipation channel 5011, and a hole portion 301 penetrating the supporting plate 8 is opened at a position opposite to the heat dissipation channel 5011. The hole portion 301 is connected to the heat dissipation channel 5011. The heat dissipation channel 5011 can be used for exhaust when thermal runaway occurs in the battery cell electrode group, and can also prevent heat from accumulating at the position where the limit assembly is located.

[0044] Preferably, in the second accommodating portion 303, a supporting protrusion 6 is formed on the side of the above-mentioned hole portion 301, and the supporting protrusion 6 protrudes toward the end plate plastic part 2. Preferably, the supporting protrusion 6 is a flat plate structure, and the supporting protrusion 6 is arranged on the supporting plate 8. More preferably, the supporting protrusion 6 is vertically arranged to the supporting plate 8. More preferably, the number of the supporting protrusions 6 is two, and the two supporting protrusions 6 are arranged opposite to each other. The end of the supporting protrusion 6 contacts the lower surface of the first limiting member 4, which is used to support the first limiting member 4 and further enhance the stability of the first limiting member 4.

[0045] More preferably, the first limiter 4 and the second limiter 5 are both made of high temperature resistant material, and among the first limiter 4 and the second limiter 5, at least the second limiter 5 is made of metal material, and the metal material used is preferably aluminum alloy.

[0046] Furthermore, a through hole 401 for penetrating and installing the second limiting member 5 is provided at the center position of the first limiting member 4. During the assembly process of the limiting component, after the upper end of the connecting portion 501 of the second limiting member 5 is penetrated into the through hole 401, the end of the connecting portion 501 protrudes a certain height relative to the first limiting member 4 to form a riveted portion 503. A hammer or other tools is used to rivet the riveted portion 503 of the connecting portion 501 to the first limiting member 4 to fix the first limiting member 4 and the second limiting member 5 together.

[0047] It can be seen that the limiting component has a strong structural strength. When the battery cell pole group suffers from thermal runaway, the end plate plastic part 2 is deformed or even melted, while the first limiting member 4 and the second limiting member 5 can remain in their original state, thereby limiting the battery cell pole group and preventing the battery cell pole group and the explosion-proof valve from moving toward the damaged end plate plastic part 2, which would affect the normal pressure relief of the explosion-proof valve.

[0048] Preferably, the bottom of the second accommodating portion 303 is provided with a through opening 7, and the number of the through openings 7 is multiple. In this embodiment, the number of the through openings 7 is specifically four, and the four through openings 7 are provided at four vertex corners of the bottom of the second accommodating portion 303. It should be noted that the bottom of the second accommodating portion 303 is the supporting plate 8, that is, the through openings 7 are formed at certain vertex corners of the supporting plate 8.

[0049] The stopper 502 is formed with the same number of notches 5021 as the through openings 7, and each notch 5021 is arranged opposite to a through opening 7, so that the inside of the slot structure of the second receiving portion 303 is connected with the outside of the slot, so as to prevent the electrolyte from accumulating in the second receiving portion 303 when the electrolyte is injected during the battery cell assembly, thereby affecting the battery cell and the later cycle life of the battery using the battery cell. The through opening 7 may be in the shape of a rectangular through hole, a circular through hole or a through hole of other shapes.

[0050] To sum up, the battery cell provided in the present application can effectively limit the position of the battery cell pole group and the explosion-proof valve arranged on the battery cell pole group relative to the end plate plastic part 2 when the battery cell triggers thermal runaway, so as to avoid the battery cell pole group blocking the explosion-proof valve, effectively improve the exhaust and heat dissipation effect of the explosion-proof valve, and can effectively delay the speed of temperature rise of the battery cell due to thermal runaway, reduce the peak temperature, greatly improve the pass rate of the battery cell thermal runaway test, and improve the safety performance of the battery cell and even the entire PACK package.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery cell, characterized in that: include: Battery cell group; An end plate assembly, the end plate assembly being arranged at the end of the battery cell electrode group; An explosion-proof valve, the explosion-proof valve being arranged on the end plate assembly; A limiting assembly, wherein the end plate assembly is provided with a mounting portion, and the limiting assembly is arranged on the mounting portion; the limiting assembly is arranged between the explosion-proof valve and the battery cell pole group; the limiting assembly can limit the distance between the battery cell pole group and the explosion-proof valve.

2. The battery cell according to claim 1, characterized in that: The limiting assembly includes a first limiting member and a second limiting member, wherein the first limiting member and the second limiting member are both arranged on the mounting portion; the first limiting member is connected to the end plate assembly, and the second limiting member is connected to the first limiting member.

3. The battery cell according to claim 1, characterized in that: The end plate assembly comprises: An end plate plastic part, the end plate plastic part is arranged facing the battery cell electrode group, and the end plate plastic part is provided with the mounting portion; The cover plate, the end plate plastic part is arranged on the cover plate, and the cover plate is located on a side of the end plate plastic part away from the battery cell electrode group; the explosion-proof valve is arranged on the cover plate.

4. The battery cell according to claim 2, characterized in that: The first limiting member has a flat plate structure, the mounting portion has a slot structure or a tube structure, a first accommodating portion is formed at the opening of the mounting portion, the shape of the first accommodating portion is adapted to the shape of the first limiting member, and the first limiting member is embedded in the first accommodating portion.

5. The battery cell according to claim 4, characterized in that: A supporting plate is arranged inside the mounting portion, a second accommodating portion is formed on one side of the supporting plate, and the second accommodating portion is communicated with the first accommodating portion; the second position-limiting member is arranged in the second accommodating portion.

6. The battery cell according to claim 5, characterized in that: The second limiting member includes a connecting portion and a stopping portion connected to the connecting portion; the connecting portion has a tube structure, and a hollow heat dissipation channel is formed inside the tube structure.

7. The battery cell according to claim 6, characterized in that: The supporting plate is formed with a hole portion, and the hole portion is communicated with the heat dissipation channel; The battery core further includes a supporting protrusion, which is disposed in the second accommodating portion and extends toward the first limiting member to support the first limiting member.

8. The battery cell according to claim 6, characterized in that: The first limiting member is provided with a through hole for penetrating the connecting portion. When the connecting portion is penetrated in the through hole, an end portion of the connecting portion protrudes relative to the through hole to form a riveted portion.

9. The battery cell according to claim 6, characterized in that: The supporting plate is provided with a through hole, and the number of the through hole is at least one; The stopper is provided with notches, the number of the notches is the same as the number of the through openings, and each of the notches is arranged opposite to one of the through openings.

10. The battery cell according to any one of claims 5 to 9, characterized in that: Of the first limiting member and the second limiting member, at least the stopper portion of the second limiting member is made of aluminum alloy.

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