Thermal runaway protection device and battery pack

Abstract

The utility model provides a thermal runaway protection device and a battery pack. The thermal runaway protection device comprises a vent valve arranged on a shell of the battery pack, the vent valve comprises a valve seat penetrating through the battery pack shell, a cover plate hinged to the valve seat and a valve element assembly arranged on the valve seat, the cover plate is located on the outer side of the battery pack shell, and an elastic piece is arranged between the cover plate and the valve seat; a valve hole penetrating through the interior and the exterior of the battery pack shell is formed in the valve seat, the valve element assembly comprises a valve element rotationally arranged in the valve hole and a driving part arranged on the valve seat, and the driving end of the driving part is connected with the valve element; the cover plate is pushed by the elastic piece to cover the valve hole in a sealing mode, and the valve element can be driven by the driving part to have a first use state for blocking the valve hole and a second use state for enabling the valve hole to be through after the cover plate is pushed open. The thermal runaway protection device disclosed by the utility model can achieve the purpose of rapid cooling, and is beneficial to the improvement of the safety of the battery pack.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a thermal runaway protection device. At the same time, the utility model also relates to a battery pack provided with the thermal runaway protection device. Background Art

[0002] The battery pack is an indispensable part of an electric vehicle. However, during the long-term use of lithium batteries, a large amount of heat energy is very likely to be generated, which poses a certain safety risk to electric vehicles, especially when driving in hot weather in summer, and it is relatively easy to cause a fire accident due to thermal runaway.

[0003] Therefore, the improvement of the thermal management cooling technology of the battery pack is an important factor affecting the safety quality of the battery pack. At present, there are many methods for cooling the battery pack on the market, but the cooling effect is poor. When the temperature of the battery pack rises rapidly or even thermal runaway occurs, the traditional cooling method may not be able to quickly cool down and avoid the occurrence of thermal runaway, which is not conducive to the improvement of the safety of the battery pack. Summary of the Utility Model

[0004] In view of this, the utility model aims to provide a thermal runaway protection device, which can improve the safety of the battery pack.

[0005] To achieve the above object, the technical solution of the utility model is realized as follows:

[0006] A thermal runaway protection device includes a ventilation valve provided on the battery pack housing.

[0007] The ventilation valve includes a valve seat penetrating the battery pack housing, a cover plate hinged on the valve seat, and a valve core assembly provided on the valve seat. The cover plate is located outside the battery pack housing, and an elastic member is provided between the cover plate and the valve seat.

[0008] The valve seat is provided with a valve hole communicating the inside and outside of the battery pack housing. The valve core assembly includes a valve core rotatably provided in the valve hole and a driving portion provided on the valve seat. The driving end of the driving portion is connected to the valve core.

[0009] The cover plate seals the valve hole under the pushing of the elastic member, and the valve core can, under the driving of the driving portion, have a first use state of blocking the valve hole and a second use state of opening the cover plate to make the valve hole communicate.

[0010] Further, the valve core includes a rotating shaft rotatably provided in the valve hole and a baffle provided on the rotating shaft. The rotating shaft is arranged along the radial direction of the valve seat and is connected to the driving end of the driving portion.

[0011] Further, the cover plate is hinged to the valve seat through a pin shaft. The elastic member includes a torsion spring sleeved on the pin shaft. One end of the torsion spring is connected to the cover plate, and the other end of the torsion spring is connected to the valve seat.

[0012] Further, a sealing member is provided on one side of the valve seat facing the cover plate.

[0013] Further, a sunk groove is provided at one end of the valve seat facing the cover plate. The sunk groove is arranged along the circumferential direction of the valve seat. The sealing member is arranged in the sunk groove, and the sealing member is a circle arranged around the circumferential direction of the sunk groove.

[0014] Further, the valve seat is arranged on the side plate of the battery pack housing.

[0015] Further, a connecting flange is provided on the side of the valve seat away from the cover plate; the connecting flange is provided with connecting holes for connecting with the inner side wall of the side plate, and / or, a sealing ring is sleeved on the valve seat, and the sealing ring is located on the side of the connecting flange facing the side plate.

[0016] Further, it further includes a BMS connected to the driving part and a detection unit connected to the BMS. The detection unit is used to detect the thermal runaway situation of the battery pack; and / or, a plurality of the vent valves are arranged on two opposite side plates of the battery pack housing.

[0017] Compared with the prior art, the present utility model has the following advantages:

[0018] The thermal runaway protection device of the present utility model can push the cover plate through the elastic member, so that the battery pack in the normal working state can maintain good sealing performance, and can drive the valve core to rotate through the driving part to push open the cover plate, so that the battery pack in the state of too high temperature or thermal runaway can achieve the purpose of rapid ventilation, heat dissipation and cooling. Thereby, the risk of thermal runaway and the loss of the battery pack during thermal runaway can be reduced, making the battery pack have better safety and economy.

[0019] In addition, the valve core includes a rotating shaft and a baffle. The rotating shaft is arranged radially along the valve seat, so that the structure is simple. The on-off of the valve hole can be realized by rotating the baffle, and then the ventilation of the battery pack can be realized. The torsion spring is adopted, the product is mature, which is beneficial to cost reduction and maintenance and replacement. A sealing member is provided on one side of the valve seat facing the cover plate, which can improve the sealing effect when the cover plate seals the valve hole. The sunk groove is provided, which is beneficial to the arrangement and installation of the sealing member and can also ensure the sealing effect.

[0020] In addition, the valve seat is provided on the side plate of the battery pack housing, which can reduce the impact on the structural performance of the battery pack housing. The connection flange is provided to facilitate the arrangement, disassembly and assembly of the ventilation valve. The sealing ring is provided to cooperate with the seal to ensure the sealing performance of the battery pack housing when the ventilation valve is not opened. The detection unit is provided, and both the detection unit and the driving part are connected to the BMS, which is conducive to realizing the automatic control of the ventilation valve. A plurality of ventilation valves are provided on two opposite side plates of the battery pack housing, which can achieve rapid cooling when the temperature in the battery pack is too high, and achieve the purpose of rapid pressure relief during thermal runaway, avoiding the spread of thermal runaway.

[0021] Another object of the present invention is to provide a battery pack, on which the above-mentioned thermal runaway protection device is provided.

[0022] Furthermore, it further includes a battery pack housing, and a plurality of battery cell modules provided in the battery pack housing, and a heat insulation plate is provided between two adjacent battery cell modules.

[0023] The battery pack of the present invention and the above-mentioned thermal runaway protection device have the same beneficial effects as compared with the traditional technology, and will not be elaborated here. Description of the Drawings

[0024] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0025] Figure 1 It is a schematic structural diagram when the ventilation valve described in the embodiment of the present invention is assembled with the battery pack housing;

[0026] Figure 2 It is a schematic structural diagram of the ventilation valve described in the embodiment of the present invention;

[0027] Figure 3 It is a schematic structural diagram when the valve seat and the valve core are assembled in the embodiment of the present invention;

[0028] Figure 4 It is a schematic structural diagram of the valve core assembly in the embodiment of the present invention;

[0029] Figure 5 It is a schematic structural diagram when the valve seat is assembled with the cover plate in the embodiment of the present invention;

[0030] Figure 6 It is a schematic structural diagram of the cover plate described in the embodiment of the present invention;

[0031] Figure 7 It is a schematic structural diagram of the sinking groove described in the embodiment of the present invention;

[0032] Figure 8 Schematic diagram of the structure when the detection unit, BMS and ventilation valve described in the embodiments of the present invention are connected;

[0033] Explanation of reference numerals:

[0034] 1. Battery pack housing;

[0035] 2. Ventilation valve; 21. Valve seat; 210. Valve hole; 211. Mounting block; 212. Sunk groove; 213. Connecting flange; 2131. Connecting hole; 22. Cover plate; 221. Pin shaft; 23. Spool assembly; 231. Spool; 2311. Rotating shaft; 2312. Baffle; 232. Driving part; 24. Sealing element; 25. Sealing ring;

[0036] 3. BMS; 4. Detection unit. Detailed implementation manners

[0037] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other.

[0038] In the description of the present invention, it should be noted that if terms indicating orientation or positional relationship such as "upper", "lower", "inner", "outer", etc. appear, they are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention 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 construed as a limitation to the present invention. In addition, if terms such as "first", "second", etc. appear, they are also only for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0039] In addition, in the description of the present invention, unless otherwise clearly defined, the terms "installation", "connection", "connection", "connecting piece" 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 directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in combination with specific situations.

[0040] The present invention will be described in detail below with reference to the drawings and in combination with embodiments.

[0041] Embodiment 1

[0042] This embodiment relates to a thermal runaway protection device, which can solve the problem that the traditional cooling method has poor effect and it is not easy to achieve rapid cooling and avoid the occurrence of thermal runaway, thus being beneficial to improving the safety performance of the battery pack.

[0043] In terms of the overall structure, asFigures 1 to 8 As shown, the thermal runaway protection device of this embodiment includes a ventilation valve 2 provided on the battery pack housing 1. Among them, the ventilation valve 2 includes a valve seat 21 penetrating the battery pack housing 1, a cover plate 22 hinged on the valve seat 21, and a valve core assembly 23 provided on the valve seat 21. The cover plate 22 is located outside the battery pack housing 1, and an elastic member is provided between the cover plate 22 and the valve seat 21.

[0044] Furthermore, a valve hole 210 penetrating the inside and outside of the battery pack housing 1 is provided on the valve seat 21. The valve core assembly 23 includes a valve core 231 rotatably provided in the valve hole 210, and a driving portion 232 provided on the valve seat 21. The driving end of the driving portion 232 is connected to the valve core 231. The cover plate 22 seals the valve hole 210 under the pushing of the elastic member, and the valve core 231 can, under the driving of the driving portion 232, have a first use state of blocking the valve hole 210 and a second use state of opening the cover plate 22 to make the valve hole 210 penetrate.

[0045] At this time, with the above settings, the elastic member can push the cover plate 22, so that the battery pack in the normal working state can maintain good airtightness, and the driving portion 232 can be used to drive the valve core 231 to rotate to open the cover plate 22, so that the battery pack in the state of too high temperature or thermal runaway can achieve the purpose of rapid ventilation, heat dissipation and temperature reduction, thereby reducing the risk of thermal runaway and the loss of the battery pack during thermal runaway, and improving the safety of the battery pack.

[0046] Based on the above overall introduction, specifically, in this embodiment, as a preferred implementation form, see Figures 2 to 4 As shown, the valve core 231 includes a rotating shaft 2311 rotatably provided in the valve hole 210 and a baffle 2312 provided on the rotating shaft 2311. The rotating shaft 2311 is arranged along the radial direction of the valve seat 21 and is connected to the driving end of the driving portion 232. With such settings, the structure can be simple, and the opening and closing of the valve hole 210 can be realized by rotating the baffle 2312, thereby realizing the ventilation of the battery pack.

[0047] Specifically, in this embodiment, as a preferred implementation form, see Figure 3 、 Figure 5 and Figure 6 As shown, the cover plate 22 is hinged on the valve seat 21 through a pin shaft 221. The elastic member includes a torsion spring sleeved on the pin shaft 221. One end of the torsion spring is connected to the cover plate 22, and the other end of the torsion spring is connected to the valve seat 21.

[0048] It is understandable that using a torsion spring makes the product mature, which is beneficial for cost reduction and maintenance and replacement. At the same time, for the convenience of assembling the cover plate 22 and the valve seat 21, the pin shafts 221 are preferably set as two respectively arranged at both ends of the base of the cover plate 22, and two relatively arranged mounting blocks 211 are provided on the valve seat 21, and the two pin shafts 221 are respectively clamped in the mounting holes of the corresponding mounting blocks 211. Of course, when necessary, common technical means in the art can also be used to set one side of the pin shaft 221 to be telescopic relative to the base, so as to facilitate the installation between the two pin shafts 221 and the corresponding mounting blocks 211.

[0049] In addition, in this embodiment, as a preferred implementation form, still referring to Figure 3 As shown, a sealing member 24 is provided on the side of the valve seat 21 facing the cover plate 22. The setting of the sealing member 24 can improve the sealing effect when the cover plate 22 seals the valve hole 210.

[0050] During specific implementation, in this embodiment, as a preferred implementation form, referring to Figure 7 As shown, a sunk groove 212 is provided at one end of the valve seat 21 facing the cover plate 22. The sunk groove 212 is arranged along the circumferential direction of the valve seat 21, the sealing member 24 is arranged in the sunk groove 212, and the sealing member 24 is a circle arranged around the circumference of the sunk groove 212. By providing the sunk groove 212, it is beneficial for the arrangement and installation of the sealing member 24 and can also ensure the sealing effect.

[0051] It is worth mentioning that the above-mentioned sealing member 24 can adopt a sealing washer well-known to those skilled in the art, and the above-mentioned sunk groove 212 can be preferably arranged on the outer peripheral wall of the valve seat 21, which is beneficial for reducing the processing difficulty of the sunk groove 212 and the disassembly and assembly difficulty of the sealing member 24.

[0052] In addition, in this embodiment, as a preferred implementation form, referring to Figure 1 As shown, the valve seat 21 is arranged on the side plate of the battery pack housing 1. The advantage of this setting is that it can reduce the impact on the structural performance of the battery pack housing 1.

[0053] In this embodiment, in detail, as a preferred implementation form, in combination with Figure 1 and Figure 2 As shown, a connecting flange 213 is provided on the side of the valve seat 21 away from the cover plate 22. A connecting hole 2131 for connecting with the inner side wall of the side plate is provided on the connecting flange 213, so that the connecting flange 213 and the valve seat 21 are connected by screwing, which is beneficial for the arrangement, disassembly and assembly of the ventilation valve 2.

[0054] Similarly, as a preferred implementation form, a sealing ring 25 is sleeved on the valve seat 21 of this embodiment, and the sealing ring 25 is located on the side of the connecting flange 213 facing the side plate. In this way, the sealing ring 25 can cooperate with the sealing member 24 to ensure the sealing performance of the battery pack housing 1 when the ventilation valve 2 is not opened.

[0055] Of course, the sealing ring 25 can adopt a sealing washer that is the same as that of the sealing member 24. Specifically in implementation, the valve seat 21 penetrates through the battery pack housing 1, the connecting flange 213 is tightly arranged against the inner wall of the side plate of the battery pack housing 1, and the cover plate 22 is arranged on the outer side of this side plate.

[0056] Meanwhile, in this embodiment, as a preferred implementation form, refer to Figure 8 As shown, the thermal runaway protection device of this embodiment further includes a BMS 3 connected to the driving part 232, and a detection unit 4 connected to the BMS 3. The detection unit 4 is used to detect the thermal runaway situation of the battery pack.

[0057] By setting the detection unit 4, and both the detection unit 4 and the driving part 232 are connected to the BMS 3, it is beneficial to realize the automatic control of the ventilation valve 2. Specifically in implementation, the detection unit 4 can adopt common thermal runaway sensor products in the art, such as battery thermal runaway detection sensors, gas sensors, pressure sensors, flame sensors, etc.

[0058] Furthermore, as a preferred implementation form, in this embodiment, a plurality of ventilation valves 2 are arranged on two opposite side plates of the battery pack housing 1. The advantage of such a setting is that it can achieve rapid cooling when the temperature in the battery pack is too high, and achieve the purpose of rapid pressure relief during thermal runaway, avoiding the spread of thermal runaway.

[0059] Of course, in this embodiment, in addition to arranging a plurality of ventilation valves 2 on two opposite side plates of the battery pack housing 1, according to the actual cooling requirements of the battery pack, such as Figure 1 As shown, only a plurality of ventilation valves 2 are arranged on one side plate, and the number and arrangement form of the ventilation valves 2 can also be adjusted according to the actual cooling requirements of the battery pack. For example, specifically, they can be four, five, six, etc. arranged at intervals along the length direction of the side plate.

[0060] The thermal runaway protection device of this embodiment can keep the battery pack in a good sealing state under normal working conditions, and can achieve the purpose of rapid ventilation, heat dissipation and cooling for the battery pack in a state of too high temperature or thermal runaway, thereby reducing the risk of thermal runaway and the loss of the battery pack during thermal runaway, making the battery pack have better safety and economy.

[0061] Embodiment 2

[0062] This embodiment relates to a battery pack, and the thermal runaway protection device in Embodiment 1 is provided on this battery pack.

[0063] In this embodiment, as a preferred implementation form, the battery pack further includes a battery pack housing 1 and a plurality of battery cell modules disposed in the battery pack housing 1, and a heat insulation plate is provided between adjacent two battery cell modules. Through the arrangement of the heat insulation plate, the spread and propagation of thermal runaway between modules can be prevented, which is beneficial to reducing the loss of the battery pack and the subsequent maintenance cost.

[0064] For the battery pack of this embodiment, through the thermal runaway protection device in Embodiment 1, the thermal runaway protection effect can be improved, and the loss and subsequent maintenance cost during thermal runaway can be reduced, thereby being beneficial to improving the overall safety of the battery pack and the market competitiveness.

[0065] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A thermal runaway protection device, characterized in that: It includes a ventilation valve provided on the battery pack housing; The ventilation valve includes a valve seat penetrating the battery pack housing, a cover plate hinged on the valve seat, and a valve core assembly provided on the valve seat. The cover plate is located outside the battery pack housing, and an elastic member is provided between the cover plate and the valve seat; A valve hole communicating with the inside and outside of the battery pack housing is provided on the valve seat. The valve core assembly includes a valve core rotatably provided in the valve hole and a driving portion provided on the valve seat. The driving end of the driving portion is connected to the valve core; The cover plate seals the valve hole under the pushing of the elastic member, and the valve core can, under the driving of the driving portion, have a first use state of blocking the valve hole and a second use state of opening the cover plate to make the valve hole communicate; 2. The thermal runaway protection device according to claim 1, characterized in that: The valve core includes a rotating shaft rotatably provided in the valve hole and a baffle provided on the rotating shaft, and the rotating shaft is arranged along the radial direction of the valve seat and is connected to the driving end of the driving portion; 3. The thermal runaway protection device according to claim 1, characterized in that: The cover plate is hinged on the valve seat through a pin shaft. The elastic member includes a torsion spring sleeved on the pin shaft. One end of the torsion spring is connected to the cover plate, and the other end of the torsion spring is connected to the valve seat; 4. The thermal runaway protection device according to claim 1, characterized in that: A sealing member is provided on one side of the valve seat facing the cover plate; 5. The thermal runaway protection device according to claim 4, characterized in that: A sink is provided at one end of the valve seat facing the cover plate. The sink is arranged along the circumferential direction of the valve seat. The sealing member is provided in the sink, and the sealing member is a circle arranged around the circumference of the sink; 6. The thermal runaway protection device according to claim 1, characterized in that: The valve seat is provided on the side plate of the battery pack housing; 7. The thermal runaway protection device according to claim 6, characterized in that: A connecting flange is provided on the side of the valve seat away from the cover plate; The connecting flange is provided with connecting holes for connecting with the inner side wall of the side plate, and / or, a sealing ring is sleeved on the valve seat, and the sealing ring is located on the side of the connecting flange facing the side plate; 8. The thermal runaway protection device according to any one of claims 1 to 7, characterized in that: It further includes a BMS connected to the driving portion and a detection unit connected to the BMS. The detection unit is used to detect the thermal runaway situation of the battery pack; and / or, A plurality of the ventilation valves are provided on two opposite side plates of the battery pack housing; 9. A battery pack, characterized in that: The battery pack is provided with the thermal runaway protection device according to any one of claims 1 to 8; 10. The battery pack according to claim 9, characterized in that: It further includes a battery pack housing and a plurality of battery cell modules provided in the battery pack housing, and a heat insulation plate is provided between adjacent two of the battery cell modules.

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