Top cover assembly and battery

Abstract

The utility model belongs to battery technical field discloses a top cover subassembly and battery. Top cover subassembly includes top cover body and explosion -proof valve subassembly, and top cover body is seted up with the mounting through -hole, explosion -proof valve subassembly includes first explosion -proof structure and second explosion -proof structure, and first explosion -proof structure sealedly connects in the top opening end of mounting through -hole, and second explosion -proof structure sealedly connects in the bottom opening end of mounting through -hole. Through above -mentioned setting, first explosion -proof structure and second explosion -proof structure can provide double -layer insurance for battery, when non -external force thermal runaway occurs in the battery inside, will first extrude the explosion -proof structure of second explosion -proof structure in the bottom of top cover body, after the rupture of second explosion -proof structure, first explosion -proof structure can provide the outer layer insurance for battery, make the high temperature electrolyte that spouts from the battery inside will not spout from the mounting through -hole, thereby make the thermal runaway of battery has been effectively controlled, avoided the battery fire combustion, and the use of battery is more safe and reliable, and the safety performance of battery carrier such as car has been further guaranteed.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a top cover assembly and a battery. Background Technology

[0002] One of the pain points of lithium-ion batteries is the safety hazard of fire and explosion. This hazard makes many potential electric vehicle customers hesitate before placing an order, indicating that the current safety measures for power batteries are still insufficient.

[0003] Currently, mass-produced batteries, especially ternary lithium batteries, will quickly catch fire and burn once thermal runaway occurs. Moreover, the top cover assembly of batteries is usually designed with a single explosion-proof valve. When thermal runaway occurs without external force, the battery will basically break through the restraint of the explosion-proof valve, causing the electrolyte inside the battery to spray out and burn. This leads to uncontrolled thermal runaway of the battery, making the safety performance of battery carriers such as automobiles lack assurance.

[0004] Therefore, it is necessary to design a top cover assembly and battery to solve the problems existing in the prior art. Utility Model Content

[0005] The purpose of this utility model is to provide a top cover assembly and battery that can mitigate the phenomenon of electrolyte spraying outwards and causing battery fire, combustion, and explosion when the battery experiences non-external thermal runaway, thereby improving safety. The structure is simple and highly feasible.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] A top cover assembly includes: a top cover body having an installation through hole; and an explosion-proof valve assembly including a first explosion-proof structure and a second explosion-proof structure, wherein the first explosion-proof structure is sealed to the top opening of the installation through hole, and the second explosion-proof structure is sealed to the bottom opening of the installation through hole.

[0008] Preferably, the explosion-proof valve assembly further includes a fire extinguishing device disposed within the mounting through hole.

[0009] Preferably, the fire extinguishing device is a cover filled with liquid, the cover having a sealing part, the melting point temperature of the sealing part being equal to the temperature of the electrolyte entering the mounting through hole when the second explosion-proof structure is opened, and the liquid including fire extinguishing agent and / or flame retardant and isolating agent.

[0010] Preferably, the explosion-proof valve assembly further includes a sensing device disposed in the mounting through hole. The sensing device is communicatively connected to the controller and configured to detect whether it comes into contact with electrolyte and send the detection signal to the controller.

[0011] Preferably, the first explosion-proof structure includes an explosion-proof sheet and a venting part. The explosion-proof sheet is sealed to the top opening end, and a venting hole is provided on the explosion-proof sheet. The venting part is sandwiched between the sensing device and the explosion-proof sheet, and the venting part is connected to the venting hole.

[0012] Preferably, the breathable part is an RO membrane.

[0013] Preferably, the first explosion-proof structure further includes an elastic insulating sealing ring, which is sandwiched between the explosion-proof sheet and the sensing device. The inner edge of the elastic insulating sealing ring is connected to the vent, and the outer edge of the elastic insulating sealing ring protrudes from the sensing device and seals the mounting through hole.

[0014] Preferably, the mounting through hole includes a first hole segment and a second hole segment. The inner diameter of the first hole segment is larger than the inner diameter of the second hole segment, and the first hole segment is closer to the top of the top cover body than the second hole segment. The first explosion-proof structure is sealed and connected to the end of the first hole segment away from the second hole segment, and the second explosion-proof structure is sealed and connected to the end of the second hole segment away from the first hole segment. The fire extinguishing device and the sensing device overlap on the stepped surface of the first hole segment and the second hole segment.

[0015] Preferably, the outer peripheral surface of the first hole section is provided with an annular boss, the explosion-proof sheet is covered on the top of the annular boss, the bottom of the explosion-proof sheet is provided with a first annular limiting groove, and the elastic insulating sealing ring is sandwiched between the bottom surface of the first annular limiting groove and the annular boss.

[0016] And / or, the top of the elastic insulating sealing ring is provided with a second annular limiting groove, and the vent is accommodated in the second annular limiting groove;

[0017] And / or, the outer periphery of the second hole section is recessed inward to provide a third annular limiting groove, and the second explosion-proof structure is accommodated in the third annular limiting groove;

[0018] And / or, the top surface of the annular boss is provided with a fourth annular limiting groove, and the explosion-proof sheet is disposed in the fourth annular limiting groove.

[0019] The battery includes a cell body, a housing, and the aforementioned top cover assembly. The cell body is housed within the housing, and the top cover assembly is sealed over the opening of the housing and electrically connected to the cell body.

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

[0021] In the top cover assembly provided in this embodiment, since a first explosion-proof structure and a second explosion-proof structure are provided on the top cover body, the first explosion-proof structure and the second explosion-proof structure can provide double protection for the battery. When thermal runaway occurs inside the battery due to non-external force, the second explosion-proof structure located at the bottom of the top cover body will be squeezed and burst first. After the second explosion-proof structure breaks, the first explosion-proof structure can provide an outer layer of protection for the battery, so that the high-temperature electrolyte sprayed from inside the battery will not spray out from the mounting through hole, thereby effectively controlling the thermal runaway of the battery, avoiding battery fire and combustion, making the use of the battery safer and more reliable, and thus ensuring the safety performance of battery carriers such as automobiles. Attached Figure Description

[0022] Figure 1 This is a top view of the top cover assembly provided by this utility model;

[0023] Figure 2 This is an exploded view of the top cover assembly provided by this utility model;

[0024] Figure 3 It is along Figure 1 Cross-sectional view at point AA;

[0025] Figure 4 yes Figure 3 A magnified view of a section at point B in the middle;

[0026] Figure 5 This is a schematic diagram of the battery structure provided by this utility model.

[0027] In the picture:

[0028] 100. Top cover assembly; 200. Outer shell;

[0029] 1. Top cover body; 11. Mounting through hole; 111. First hole section; 112. Second hole section; 1121. Third annular limiting groove; 113. Annular boss; 1131. Fourth annular limiting groove;

[0030] 2. Explosion-proof valve assembly; 21. First explosion-proof structure; 211. Explosion-proof sheet; 2111. Vent hole; 2112. First annular limiting groove; 212. Vent part; 213. Elastic insulating sealing ring; 2131. Second annular limiting groove; 22. Second explosion-proof structure; 23. Fire extinguishing device; 24. Sensing device. Detailed Implementation

[0031] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0032] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction 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.

[0033] 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.

[0034] In the description of this embodiment, the terms "upper," "lower," "right," and "left," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0035] The technical solution provided by this utility model will be described below with reference to the accompanying drawings and specific embodiments.

[0036] Combination Figures 1 to 4 As shown, this embodiment provides a top cover assembly 100, which is applied to a battery and includes a top cover body 1 and an explosion-proof valve assembly 2. The top cover body 1 has a mounting through hole 11 for mounting the explosion-proof valve assembly 2. The explosion-proof valve assembly 2 includes a first explosion-proof structure 21 and a second explosion-proof structure 22. The first explosion-proof structure 21 is sealed to the top opening of the mounting through hole 11, and the second explosion-proof structure 22 is sealed to the bottom opening of the mounting through hole 11.

[0037] In the top cover assembly 100 provided in this embodiment, since a first explosion-proof structure 21 and a second explosion-proof structure 22 are provided on the top cover body 1, the first explosion-proof structure 21 and the second explosion-proof structure 22 can provide double protection for the battery. When non-external force thermal runaway occurs inside the battery, the second explosion-proof structure 22 located at the bottom of the top cover body 1 will be squeezed and burst first. After the second explosion-proof structure 22 breaks, the first explosion-proof structure 21 can provide an outer layer of protection for the battery, so that the high-temperature electrolyte sprayed from inside the battery will not spray out from the mounting through hole 11, thereby effectively controlling the thermal runaway of the battery, avoiding battery fire and combustion, making the use of the battery safer and more reliable, and thus ensuring the safety performance of battery carriers such as automobiles.

[0038] In this embodiment, reference Figure 2 , Figure 3 As shown, the explosion-proof valve assembly 2 also includes a fire extinguishing device 23, which is installed in the mounting through hole 11. When the second explosion-proof structure 22 is broken, the fire extinguishing device 23 is activated and can quickly remove the heat inside the battery, reduce the battery temperature, and prevent the battery from further thermal reaction, thereby achieving the purpose of controlling the battery fire and preventing the battery from continuing to thermally run away. This makes the battery thermal runaway slower and more controllable, further improving the safety of battery use.

[0039] Preferably, the fire extinguishing device 23 is a cover filled with liquid, and the cover has a sealing part. The melting point temperature of the sealing part is equal to the temperature of the electrolyte entering the mounting through hole 11 when the second explosion-proof structure 22 is opened, and the liquid includes at least one of a fire extinguishing agent and a flame retardant isolating agent. For example, the fire extinguishing agent can be perfluorohexanone. After the fire extinguishing device 23 comes into contact with the high-temperature electrolyte sprayed from inside the battery, the sealing part of the fire extinguishing device 23 is heated and melts. At the same time, the perfluorohexanone inside the fire extinguishing device 23 is heated and can quickly evaporate and carry away the heat inside the battery, thereby achieving the purpose of reducing the battery temperature. The flame retardant isolating agent is an organophosphorus flame retardant isolating agent. Organophosphorus compounds can decompose into a carbonized layer covering the mounting through hole 11 at high temperatures, thereby isolating oxygen and heat, and achieving the function of isolating oxygen and extinguishing fire.

[0040] Optionally, the explosion-proof valve assembly 2 provided in this embodiment also includes a sensing device 24. The sensing device 24 is disposed in the mounting through hole 11 and is communicatively connected to the controller. When the second explosion-proof structure 22 breaks and the extinguishing agent is released and enters the battery, the sensing device 24 will also come into contact with the electrolyte at the same time. At this time, the sensing device 24 can send the detection signal to the controller in time, and the controller sends an alarm signal to the outside of the battery so that the staff can deal with the thermal runaway battery in time and prevent the battery from continuing to thermal runaway.

[0041] refer to Figure 4As shown, in this embodiment, the installation method of the fire extinguishing device 23 and the sensing device 24 in the mounting through hole 11 is as follows: the mounting through hole 11 includes a first hole segment 111 and a second hole segment 112. The inner diameter of the first hole segment 111 is larger than the inner diameter of the second hole segment 112, and the first hole segment 111 is closer to the top of the top cover body 1 than the second hole segment 112. The first explosion-proof structure 21 is sealed and connected to the end of the first hole segment 111 away from the second hole segment 112. The second explosion-proof structure 22 is sealed and connected to the end of the second hole segment 112 away from the first hole segment 111. The fire extinguishing device 23 and the sensing device 24 overlap on the stepped surface of the first hole segment 111 and the second hole segment 112. In the above installation process, this embodiment first welds the first explosion-proof structure 21 onto the second hole section 112, then attaches the fire extinguishing device 23 to the stepped surface of the first hole section 111 and the second hole section 112, and the sensing device 24 is attached to the top of the fire extinguishing device 23. Finally, the second explosion-proof structure 22 is welded onto the first hole section 111. This top cover assembly 100 structure can realize the installation of the fire extinguishing device 23 and the sensing device 24 without additional parts, thereby simplifying the structure and improving the production efficiency of the top cover assembly 100 and the battery.

[0042] Specifically, in this embodiment, the first explosion-proof structure 21 includes an explosion-proof sheet 211 and a vent 212. The explosion-proof sheet 211 is sealed to the top opening, and a vent hole 2111 is provided on the explosion-proof sheet 211. The vent 212 is sandwiched between the sensing device 24 and the explosion-proof sheet 211, and the vent 212 is connected to the vent hole 2111. When the battery experiences thermal runaway, high-temperature gas can be discharged outward through the vent 212 and the vent hole 2111, enabling the first explosion-proof structure 21 to provide a function of leaking gas but not electrolyte, thereby timely depressurization, preventing excessively high internal temperature and pressure of the battery, and greatly reducing the risk of further battery explosion.

[0043] Preferably, in this embodiment, the vent 212 is made of an RO (Reverse Osmosis) membrane. Since the RO membrane is a non-metallic material, the detection signal of the sensor 24 can be transmitted to the controller through the vent 212 and the vent 2111, which prevents the sensor 24 from being enclosed in a Faraday cage and ensures that the sensor 24 maintains a communication connection with the controller set outside the battery, thereby providing early warning signals to the staff in a timely manner.

[0044] More specifically, in this embodiment, the first explosion-proof structure 21 further includes an elastic insulating sealing ring 213. The elastic insulating sealing ring 213 is sandwiched between the explosion-proof sheet 211 and the sensing device 24. The inner edge of the elastic insulating sealing ring 213 is connected to the vent 212, and the outer edge of the elastic insulating sealing ring 213 protrudes from the sensing device 24 and is sealed in the mounting through hole 11. On the one hand, the elastic insulating sealing ring 213 can press against the top of the sensing device 24, so that after the top cover assembly 100 is assembled, the elastic insulating sealing ring 213 can limit the horizontal position of the sensing device 24 and the fire extinguishing device 23, ensuring that the sensing device 24 and the fire extinguishing device 23 can respond to thermal runaway in a timely manner. On the other hand, it can also block the gap between the fire extinguishing device 23, the sensing device 24 and the inner wall of the mounting through hole 11 and the outside of the battery, so that the sealing effect of the elastic insulating sealing ring 213 on the electrolyte is better, further enhancing the safety of the battery. For example, in this embodiment, the elastic insulating sealing ring 213 is a silicone ring. Of course, in other parallel embodiments, the elastic insulating sealing ring 213 can also be made of other elastic materials such as rubber, fluororubber, and polytetrafluoroethylene. This utility model is not limited in this respect.

[0045] It should also be noted that, in order to ensure the stable installation of the fire extinguishing device 23 and the sensing device 24 within the mounting through hole 11 while effectively reducing the overall thickness of the top cover assembly 100 after assembly, in this embodiment, an annular boss 113 is provided on the outer peripheral surface of the first hole segment 111. The first explosion-proof structure 21 covers the top of the annular boss 113. The bottom of the explosion-proof plate 211 in the first explosion-proof structure 21 is provided with a first annular limiting groove 2112. The elastic insulating sealing ring 213 is sandwiched between the bottom surface of the first annular limiting groove 2112 and the annular boss 113, so that the elastic insulating sealing ring 213 can be wrapped inside the explosion-proof plate 211. This not only restricts the horizontal movement of the elastic insulating sealing ring 213 and ensures the installation stability of the elastic insulating sealing ring 213, but also reduces the space occupation rate of the elastic insulating sealing ring 213 on the top cover assembly 100, thereby improving the battery energy density.

[0046] Furthermore, in this embodiment, a second annular limiting groove 2131 is provided on the top of the elastic insulating sealing ring 213, and the vent 212 is accommodated in the second annular limiting groove 2131, so that the vent 212 can be embedded in the elastic insulating sealing ring 213, avoiding the situation where the vent 212 is superimposed on the elastic insulating sealing ring 213, which would increase the thickness of the top cover assembly 100, thereby further ensuring the high energy density of the battery.

[0047] Optionally, in this embodiment, the outer periphery of the second hole segment 112 is recessed inward to provide a third annular limiting groove 1121, and the second explosion-proof structure 22 is accommodated in the third annular limiting groove 1121, thereby avoiding the situation where the second explosion-proof structure 22 is superimposed on the bottom of the top cover body 1, which would cause the thickness of the top cover assembly 100 to increase, so that the thickness of the top cover assembly 100 can be further reduced.

[0048] Optionally, in this embodiment, a fourth annular limiting groove 1131 is provided on the top surface of the annular boss 113, and the explosion-proof sheet 211 is disposed in the fourth annular limiting groove 1131, thereby reducing the distance between the annular boss 113 and the explosion-proof sheet 211. In this way, through the setting of the first annular limiting groove 2112, the second annular limiting groove 2131, the third annular limiting groove 1121 and the fourth annular limiting groove 1131, the thickness of the top cover assembly 100 is greatly reduced, making the top cover assembly 100 thinner. The thickness of the top cover assembly 100 can meet the requirements of actual working conditions, significantly improving the energy density and range of the battery, making it equally suitable for compact installation spaces and with a wider range of applications.

[0049] This embodiment also provides a battery, see reference. Figure 5 As shown, the battery includes a cell body (not shown), a housing 200, and the aforementioned top cover assembly 100. The cell body is housed within the housing 200, and the top cover assembly 100 seals the opening of the housing 200. The top cover assembly 100 is electrically connected to the cell body, thereby enabling the cell body to connect to external electrical equipment. By incorporating the top cover assembly 100 within the battery, and because the top cover assembly 100 includes a first explosion-proof structure 21 and a second explosion-proof structure 22 spaced apart, a second layer of protection can be provided by the first explosion-proof structure 21 even if the battery experiences thermal runaway and the second explosion-proof structure 22 ruptures. This prevents electrolyte leakage that could lead to battery combustion and explosion, thus making battery thermal runaway slower and more controllable, improving battery safety, and eliminating obstacles for users purchasing battery carriers such as electric vehicles.

[0050] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0051] 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 various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments 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. A top cover assembly, characterized in that, include: The top cover body (1) has an installation through hole (11) on it; An explosion-proof valve assembly (2) includes a first explosion-proof structure (21) and a second explosion-proof structure (22). The first explosion-proof structure (21) is sealed to the top opening of the mounting through hole (11), and the second explosion-proof structure (22) is sealed to the bottom opening of the mounting through hole (11).

2. The top cover assembly according to claim 1, characterized in that, The explosion-proof valve assembly (2) also includes a fire extinguishing device (23), which is disposed in the mounting through hole (11).

3. The top cover assembly according to claim 2, characterized in that, The fire extinguishing device (23) is a cover filled with liquid. The cover has a sealing part. The melting point temperature of the sealing part is equal to the temperature of the electrolyte entering the mounting through hole (11) when the second explosion-proof structure (22) is opened. The liquid includes fire extinguishing agent and / or flame retardant and isolating agent.

4. The top cover assembly according to claim 2, characterized in that, The explosion-proof valve assembly (2) also includes a sensing device (24), which is disposed in the mounting through hole (11). The sensing device (24) is communicatively connected to the controller and configured to detect whether it is in contact with electrolyte and send the detection signal to the controller.

5. The top cover assembly according to claim 4, characterized in that, The first explosion-proof structure (21) includes an explosion-proof sheet (211) and a vent (212). The explosion-proof sheet (211) is sealed to the top opening end, and a vent hole (2111) is provided on the explosion-proof sheet (2111). The vent (212) is sandwiched between the sensing device (24) and the explosion-proof sheet (211), and the vent (212) is connected to the vent hole (2111).

6. The top cover assembly according to claim 5, characterized in that, The breathable part (212) is an RO membrane.

7. The top cover assembly according to claim 5, characterized in that, The first explosion-proof structure (21) further includes an elastic insulating sealing ring (213), which is sandwiched between the explosion-proof sheet (211) and the sensing device (24). The inner edge of the elastic insulating sealing ring (213) is connected to the vent (212), and the outer edge of the elastic insulating sealing ring (213) protrudes from the sensing device (24) and seals the mounting through hole (11).

8. The top cover assembly according to claim 7, characterized in that, The mounting through hole (11) includes a first hole section (111) and a second hole section (112). The inner diameter of the first hole section (111) is larger than the inner diameter of the second hole section (112), and the first hole section (111) is closer to the top of the top cover body (1) than the second hole section (112). The first explosion-proof structure (21) is sealed to the end of the first hole section (111) away from the second hole section (112), and the second explosion-proof structure (22) is sealed to the end of the second hole section (112) away from the first hole section (111). The fire extinguishing device (23) and the sensing device (24) overlap on the stepped surface of the first hole section (111) and the second hole section (112).

9. The top cover assembly according to claim 8, characterized in that, The outer peripheral surface of the first hole segment (111) is provided with an annular boss (113), the explosion-proof sheet (211) is covered on the top of the annular boss (113), the bottom of the explosion-proof sheet (211) is provided with a first annular limiting groove (2112), and the elastic insulating sealing ring (213) is sandwiched between the bottom surface of the first annular limiting groove (2112) and the annular boss (113). And / or, the top of the elastic insulating sealing ring (213) is provided with a second annular limiting groove (2131), and the vent (212) is accommodated in the second annular limiting groove (2131); And / or, the outer periphery of the second hole segment (112) is recessed inward to provide a third annular limiting groove (1121), and the second explosion-proof structure (22) is housed in the third annular limiting groove (1121); And / or, the top surface of the annular boss (113) is provided with a fourth annular limiting groove (1131), and the explosion-proof sheet (211) is disposed in the fourth annular limiting groove (1131).

10. A battery, characterized in that, The device includes a battery cell body, a housing (200), and a top cover assembly (100) according to any one of claims 1-9. The battery cell body is housed within the housing (200), and the top cover assembly (100) is sealed over the opening of the housing (200) and electrically connected to the battery cell body.

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