Battery thermal runaway prevention and control device

Abstract

The utility model discloses a battery thermal runaway prevention and control device, including battery body, temperature monitoring unit for monitoring battery body temperature, radiator located at one side of battery body, still include first explosion -proof valve and second explosion -proof valve respectively located at both ends of battery body, and, switch valve no.

Description

Technical Field

[0001] This utility model relates to the design, production and safety of lithium-ion batteries, and in particular to a battery thermal runaway prevention and control device. Background Technology

[0002] Lithium-ion batteries are widely used in electric vehicles, energy storage systems, and other fields due to their high energy density and long cycle life. However, under abuse conditions such as overcharging and internal short circuits, batteries are prone to thermal runaway, which causes a rapid increase in heat and gas inside, leading to a surge in temperature and pressure, and ultimately causing serious safety accidents such as fires and explosions.

[0003] Currently, most technical solutions for improving the safety of lithium-ion batteries are decentralized and passive. For example, common protective measures include: installing a single explosion-proof valve on the top cover of the battery to release pressure when the internal pressure is too high; or adding an external cooling system at the battery module level to cool the battery pack as a whole through air cooling or liquid cooling; or installing a total flooding fire extinguishing device in the battery compartment.

[0004] However, the aforementioned existing technologies have significant shortcomings: First, a single explosion-proof valve can only achieve one-time pressure relief and cannot intervene in the thermal runaway process in a graded and orderly manner. Once opened, it becomes ineffective, and the released high-temperature, flammable, and explosive gases may directly cause secondary hazards inside the battery pack. Second, the external cooling system is isolated from the core of the thermal runaway reaction inside the battery, resulting in high thermal resistance and slow response. When thermal runaway occurs rapidly inside the cell, external heat dissipation is no longer effective in suppressing it. Utility Model Content

[0005] The purpose of this invention is to provide a battery thermal runaway prevention and control device that can deeply integrate functions such as temperature monitoring, external heat dissipation, internal suppression and medium recovery, thereby suppressing thermal runaway at its source and improving safety.

[0006] To achieve the above objectives, this utility model provides the following technical solution: A battery thermal runaway prevention device includes a battery body and a heat sink located on one side of the battery body. The battery body has a first explosion-proof valve and a second explosion-proof valve at both ends, and a cooling circuit is provided between the first explosion-proof valve and the second explosion-proof valve. A switching valve, a circulating working fluid storage tank and a gas-liquid separator are sequentially connected to the cooling circuit. The circulating working fluid storage tank is also connected to the heat sink through a return pipe.

[0007] A further solution includes a temperature monitoring unit for monitoring the temperature of the battery itself.

[0008] A further solution: A second switching valve is connected between the first explosion-proof valve and the radiator.

[0009] A further solution: the opening pressure of the first explosion-proof valve is set to be lower than the opening pressure of the second explosion-proof valve.

[0010] A further solution: The opening pressure of the first explosion-proof valve is 0.1-0.4 MPa.

[0011] A further solution: The opening pressure of the second explosion-proof valve is 0.4-0.9 MPa.

[0012] A further option: the switching valve is a pneumatic valve or an electric valve.

[0013] A further option: the second switching valve is a pneumatic valve or an electric valve.

[0014] Compared with the prior art, the beneficial effects of this utility model are: This invention creatively integrates the two originally separate lines of defense—external heat dissipation and internal fire suppression—with the medium recovery function into a single integrated system, achieving proactive, hierarchical, and closed-loop management of battery thermal runaway.

[0015] Specifically, in the early stages of temperature anomalies, external circulation cooling is activated to attempt to contain the fault in its nascent stage. When thermal runaway has already occurred irreversibly, the system can immediately switch to internal injection mode, directly delivering flame retardant to the ignition point inside the battery cell. Through efficient vaporization heat absorption and chemical flame retardancy, rapid cooling and fire extinguishing are achieved. Simultaneously, the unique recycling and purification design allows the extinguishing medium to be recycled, improving the system's economic efficiency and environmental friendliness. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model; In the diagram: 1-Battery body, 2-Temperature monitoring unit, 3-Radiator, 4-First explosion-proof valve, 5-Second explosion-proof valve, 6-Switch valve one, 7-Circulating working fluid storage tank, 8-Gas-liquid separation filter, 9-Transfer pump, 10-Switch valve two, 11-Return pipe. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] In the description of this utility model, it should be noted that the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the utility model product is usually placed in during use. They are only for the convenience of describing this utility model and simplifying the description, 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.

[0019] Please see Figure 1 This embodiment discloses a battery thermal runaway prevention and control device, including a battery body 1, a temperature monitoring unit 2 for monitoring the temperature of the battery body 1, and a radiator 3 located on one side of the battery body 1; it also includes a first explosion-proof valve 4 and a second explosion-proof valve 5 respectively located at both ends of the battery body 1, and a switching valve 6, a circulating working fluid storage tank 7, and a gas-liquid separation filter 8 sequentially connected between the first explosion-proof valve 4 and the second explosion-proof valve 5; the circulating working fluid storage tank 7 is also connected to the radiator 3 through a return pipe 11. By integrating the battery body 1, temperature monitoring unit 2, radiator 3, first explosion-proof valve 4, second explosion-proof valve 5, switching valve 6, circulating working fluid storage tank 7, and gas-liquid separation filter 8 into one unit, a collaborative protection system with external heat dissipation, internal fire extinguishing, and media recovery functions is constructed, realizing multi-level safety intervention for the entire process of thermal runaway.

[0020] This device is mainly used in lithium-ion battery applications where safety requirements are extremely high, such as power battery packs for electric vehicles, large-scale electrochemical energy storage systems, high-power electronic devices, and airborne power supplies in the aerospace field. Through its built-in integrated active protection system, it can quickly intervene in the entire process from external heat dissipation to internal fire suppression and explosion prevention when the battery is at risk of thermal runaway. This effectively prevents the thermal runaway of a single cell from spreading into a fire or explosion accident in the entire system, thereby significantly improving the safety and reliability of the overall system and protecting life and property from loss.

[0021] Furthermore, a transfer pump 9 is also provided between the circulating working medium storage tank 7 and the switch valve 6. By setting up the transfer pump 9, a stable power is provided for the directional flow of the circulating working medium throughout the system, ensuring that both the external cooling circulation flowing to the radiator 3 and the internal injection process of opening the first explosion-proof valve 4 can be carried out reliably and efficiently.

[0022] Furthermore, a second switching valve 10 is connected between the first explosion-proof valve 4 and the radiator 3. By setting the second switching valve 10, the fluid passage can be quickly and accurately switched between the two working modes of "external heat dissipation" and "internal fire extinguishing", ensuring the reliability of the system's response to different fault stages.

[0023] Furthermore, the opening pressure of the first explosion-proof valve 4 is set lower than the opening pressure of the second explosion-proof valve 5. By making the opening pressure of the first explosion-proof valve 4 lower than that of the second explosion-proof valve 5, a graded pressure relief and injection mechanism is established to ensure that the flame retardant can be preferentially injected into the battery from the first explosion-proof valve 4, forming an orderly and controllable protection process and avoiding the problem of failure after a single explosion-proof valve is released all at once.

[0024] Furthermore, the opening pressure of the first explosion-proof valve 4 is 0.1-0.4 MPa. By specifically limiting the opening pressure of the first explosion-proof valve 4 to 0.1 to 0.4 MPa, a clear pressure threshold is provided for the manufacture and selection of the valve, ensuring that it can be accurately triggered in the early stage of thermal runaway and achieve timely intervention.

[0025] Furthermore, the opening pressure of the second explosion-proof valve 5 is 0.4-0.9 MPa. By specifically limiting the opening pressure of the second explosion-proof valve 5 to 0.4 to 0.9 MPa, it serves as a venting channel for higher pressures. This allows it to be activated after the first explosion-proof valve 4 to maintain flow, while also preventing excessive internal pressure in the battery from causing the casing to rupture, thus providing ultimate safety assurance.

[0026] Furthermore, both switch valve 6 and switch valve 10 are pneumatic or electric valves. By limiting switch valve 6 to a pneumatic or electric valve, the system can achieve rapid and automatic remote control of critical flow paths leading to the battery, meeting the requirements for real-time response.

[0027] It should be noted that the working fluid stored in the circulating working fluid storage tank 7 is a liquid medium with both good fluidity and high flame-retardant properties, preferably a phosphorus-based flame retardant. It plays a dual role in the system: as a coolant during normal thermal management and as a flame retardant during thermal runaway. Although phosphorus-based flame retardants are not the most preferred coolant, the first stage (external heat dissipation) is an early intervention for temperature anomalies. At this stage, the heat generation power has not yet reached its peak, and the extreme requirements for cooling efficiency are relatively low. Even if the cooling efficiency is only 60%-70% of that of traditional coolants, it is sufficient.

[0028] During operation, this invention guides the working medium to flow in two different loops through valve switching, achieving full-process protection from early warning to final suppression. Its core operating mechanism can be divided into the following two modes: Mode 1: External circulation cooling mode (early warning and intervention) This mode is activated when the battery temperature rises abnormally but before severe thermal runaway occurs. Its core objective is active cooling to prevent escalation. Temperature monitoring unit 2 monitors the temperature of the battery body 1 in real time. When the temperature exceeds the first safety threshold, it activates the delivery pump 9 and opens the second switch valve 10, while keeping the first switch valve 6 closed. At this time, the flow path of the circulating working fluid is: circulating working fluid tank 7 → delivery pump 9 → second switch valve 10 → radiator 3 → return pipe 11 → circulating working fluid tank 7. As the working fluid flows through the radiator 3, it dissipates the heat it carries into the environment. The cooled working fluid then flows back to the circulating working fluid tank 7, forming a closed external cooling cycle that continuously cools the battery body 1.

[0029] Mode 2: Internal Injection Fire Extinguishing Mode (Thermal Runaway Suppression and Recovery) This mode is activated when external heat dissipation is ineffective, the battery temperature continues to rise, and thermal runaway begins. Its core objective is to directly extinguish the internal ignition source and recover the medium. When the temperature monitoring unit reports that cooling is ineffective and the temperature or pressure reaches the second safety threshold, a mode switch is immediately executed: switch valve 2 10 is closed, and switch valve 1 6 is opened. The transfer pump 9 continues to operate, and the working fluid flow path is switched to: circulating working fluid storage tank 7 → transfer pump 9 → switch valve 1 6 → first explosion-proof valve 4. Under the pumping pressure, the first explosion-proof valve 4, which has a lower opening pressure, is opened, and the liquid working fluid is directly injected into the battery body 1. The working fluid comes into direct contact with the high-temperature battery cell. Through the heat absorption of vaporization of the liquid working fluid and its own chemical flame-retardant effect, the internal temperature of the battery is rapidly reduced and the flame is suffocated. The high-pressure gas-liquid mixture accumulated inside the battery body 1 then opens the second explosion-proof valve 5, which has a higher opening pressure, and is discharged to the gas-liquid separation filter 8. In the gas-liquid separation filter 8, toxic and combustible gases are separated and safely discharged, solid residues are filtered, and the purified liquid working fluid is transported back to the circulating working fluid storage tank 7 to realize the recycling of the working fluid.

[0030] Although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0031] Therefore, the above description is only a preferred embodiment of this application and is not intended to limit the scope of this application; that is, all equivalent modifications made in accordance with the scope of the claims of this application shall be within the protection scope of the claims of this application.

Claims

1. A battery thermal runaway prevention device, comprising a battery body (1) and a heat sink (3) disposed on one side of the battery body (1), characterized in that, The battery body (1) is provided with a first explosion-proof valve (4) and a second explosion-proof valve (5) at both ends. A cooling circuit is provided between the first explosion-proof valve (4) and the second explosion-proof valve (5). A switch valve (6), a circulating working fluid storage tank (7) and a gas-liquid separation filter (8) are connected in sequence on the cooling circuit. The circulating working fluid storage tank (7) is also connected to the radiator (3) through a return pipe (11).

2. The battery thermal runaway prevention device according to claim 1, characterized in that, It also includes a temperature monitoring unit (2) for monitoring the temperature of the battery body (1).

3. The battery thermal runaway prevention device according to claim 1, characterized in that, The cooling circuit also includes a delivery pump (9) located between the circulating working fluid storage tank (7) and the switch valve (6).

4. The battery thermal runaway prevention device according to claim 1, characterized in that, A second switching valve (10) is connected between the first explosion-proof valve (4) and the radiator (3).

5. The battery thermal runaway prevention device according to claim 1, characterized in that, The opening pressure of the first explosion-proof valve (4) is less than the opening pressure setting of the second explosion-proof valve (5).

6. The battery thermal runaway prevention device according to claim 1, characterized in that, The opening pressure of the first explosion-proof valve (4) is 0.1-0.4 MPa.

7. The battery thermal runaway prevention device according to claim 1, characterized in that, The opening pressure of the second explosion-proof valve (5) is 0.4-0.9 MPa.

8. The battery thermal runaway prevention device according to claim 1, characterized in that, The switching valve (6) is a pneumatic valve or an electric valve.

9. The battery thermal runaway prevention device according to claim 4, characterized in that, The second switching valve (10) is a pneumatic valve or an electric valve.

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