Instantaneous heat energy release device for thermal runaway fault of battery pack

Abstract

The utility model discloses an instantaneous heat energy release device for a thermal runaway fault of a battery pack. The device comprises an arc-shaped heat dissipation main body matched with the side surface of a cylindrical battery cell, an upper cover and a locking device, a plurality of evaporation holes are formed in the arc-shaped heat dissipation body and filled with liquid heat dissipation media. In a normal state, the locking device fixes the upper cover and the arc-shaped heat dissipation main body, so that the upper cover seals the evaporation holes; and when the temperature of the battery cell rises to a certain temperature, the upper cover is instantly separated from the arc-shaped heat dissipation main body, and the liquid medium rapidly evaporates to absorb heat, so that instant emergency heat dissipation is realized. The arc-shaped structure adapts to the side surface of the battery cell, is convenient to install, does not damage the surface of the battery cell, provides a certain thermal expansion space for the battery, and can be widely applied to thermal safety management of a power battery pack and an energy storage system in combination with an evaporation endothermic reaction effect.

Description

A device for instantaneous heat release in the event of thermal runaway of a battery pack Technical Field

[0001] This article relates to an instantaneous thermal energy release device for battery pack thermal runaway faults. Background Technology

[0002] With the rapid development of electric vehicles and energy storage systems, lithium-ion batteries have become the mainstream choice due to their high energy density and long cycle life. However, during the charging and discharging process, if the heat generated inside the battery cells due to internal resistance, chemical reactions, and local short circuits cannot be dissipated in time, it can easily lead to thermal runaway. Thermal runaway not only causes a sharp decline in cell performance but may also trigger a chain reaction, causing the entire battery pack to catch fire or even explode.

[0003] Currently, battery pack heat dissipation design mainly focuses on the end areas of the cells. However, due to their large surface area and close contact with adjacent cells, heat tends to accumulate more easily on the sides during actual operation. Especially at high charge / discharge rates or high ambient temperatures, the local temperature rise rate on the sides can be 2-3 times that of the ends, making them a high-risk area for thermal runaway. Existing technologies often employ fully enclosed structures for side heat dissipation, which, while increasing the heat dissipation area, suffer from problems such as complex installation, difficult maintenance, and response delays. Furthermore, excessive enclosure may affect the cell's expansion space, accelerating aging.

[0004] Furthermore, traditional cooling systems (such as liquid cooling and air cooling) rely on continuous external energy, making it difficult to achieve instantaneous heat dissipation in the event of thermal runaway. For example, liquid cooling systems require pumping to circulate coolant, with a response time typically ranging from several seconds to tens of seconds, while thermal runaway can spread in just milliseconds.

[0005] In summary, existing heat dissipation solutions for the side of battery cells have shortcomings such as insufficient response speed, complex structure, and poor adaptability. In particular, there is currently no good fast-response solution for instantaneous heat dissipation in the event of thermal runaway of the battery pack. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide an instantaneous heat release device for battery pack thermal runaway faults. The device is designed for rapid heat dissipation from the sides of the battery cells within the battery pack. The specific solution is as follows:

[0007] An instantaneous heat release device for thermal failure of a battery pack installed on the side of a cylindrical cell includes an arc-shaped heat dissipation body, a top cover, and a locking device for connecting the arc-shaped heat dissipation body and the top cover. The arc-shaped heat dissipation body has a plurality of evaporation holes inside, and the evaporation holes are countersunk holes filled with liquid.

[0008] The top cover abuts against the top of the arc-shaped heat dissipation body. When the locking device tightly connects the arc-shaped evaporation body and the top cover, the lower surface of the top cover abuts against the opening of the evaporation hole. When the locking device no longer tightly connects the arc-shaped evaporation body and the top cover, the lower surface of the top cover no longer abuts against the opening of the evaporation hole.

[0009] The arc-shaped heat dissipation body is designed to fit cylindrical battery cells well without damaging their outer surface. Especially after prolonged use, the arc shape prevents thermal expansion from affecting the cells' normal expansion. Furthermore, installation is faster and more convenient than with a fully enclosed design.

[0010] To facilitate rapid separation of the top cover from the arc-shaped heat dissipation body after heating, the locking device includes a connecting post, a spring, a spring clip, and a hot-melt wire. The top of the connecting post is connected to the lower surface of the top cover, and the lower surface of the spring clip is connected to the arc-shaped heat dissipation body. A spring is provided between the connecting post and the spring clip. The spring clip is U-shaped, with opposing protrusions on its inner side. A hot-melt wire is located below the protrusions. The protrusions are used to engage the lower end of the connecting post, and the hot-melt wire is used to limit the opening size of the spring clip.

[0011] Another method does not use a thermal fuse; the locking device includes a connecting post, a spring, and a snap-lock.

[0012] The top of the connecting post is connected to the lower surface of the upper cover, and the lower surface of the spring buckle is connected to the arc-shaped heat dissipation body. A spring is provided between the connecting post and the spring buckle. The spring buckle is U-shaped, and the inner side of the spring buckle is provided with opposing protrusions. In the normal state of the spring buckle, the spring buckle is engaged with the lower end of the connecting post.

[0013] To save on installation dimensions and achieve a better sealing effect, the lower surface of the upper cover is provided with several spring mounting holes, the size of which matches the size of the spring;

[0014] The upper surface of the arc-shaped heat dissipation body is provided with a countersunk hole that matches the spring mounting hole, and the diameter of the countersunk hole matches the maximum outer dimensions of the spring buckle.

[0015] To achieve rapid heat dissipation, the arc-shaped heat dissipation body has several evaporation holes inside. The liquid inside these holes is one or a mixture of water, ethanol, ethylene glycol, or glycerol. Simultaneously, if the temperature reaches a certain level, the pressure generated by the vaporization of the internal liquid can open the top cover. Even though the thermal fuse has not yet activated, the top cover can still be opened normally, thus achieving instantaneous heat dissipation.

[0016] Furthermore, the depth of the evaporation hole is 3 / 4 to 2 / 3 of the overall height of the arc-shaped heat dissipation body.

[0017] Furthermore, the melting point of the hot melt wire is 80-95℃.

[0018] Furthermore, the spring clip is made of spring steel, with a rounded bottom and a straight upper section.

[0019] Furthermore, the lower surface of the upper cover is coated with a high-temperature resistant silicone layer with a thickness of 0.1~0.5mm. Beneficial effects

[0020] This invention relates to an instantaneous heat release device for battery pack thermal runaway faults, which can quickly function when a battery pack experiences thermal runaway. When the temperature reaches the melting point of the thermal fuse, the device immediately activates, causing the liquid in the evaporation holes to evaporate rapidly, absorbing a large amount of heat and achieving emergency instantaneous heat dissipation. This rapid response mechanism effectively curbs the spread of thermal runaway, preventing further damage to the faulty cell and surrounding cells from localized high temperatures, significantly reducing the risk of a chain reaction of thermal runaway in the entire battery pack, and providing strong protection for the safe operation of the battery pack. Attached Figure Description

[0021] Figure 1 is a schematic diagram of a battery cell equipped with an instantaneous heat release device;

[0022] Figure 2 is a schematic diagram of the structure of a single instantaneous heat release device;

[0023] Figure 3 is a cross-sectional schematic diagram of the evaporation holes in the arc-shaped heat dissipation body;

[0024] Figure 4 is a schematic diagram of the installation of the arc-shaped heat dissipation body and the top cover;

[0025] Figure 5 is a reverse view of the top cover;

[0026] Figure 6 is a schematic diagram of the locking device;

[0027] Figure 7 is a front view of the locking device;

[0028] Figure 8 is a magnified view of part A in Figure 4;

[0029] In the diagram: 1. Arc-shaped heat dissipation body 2. Locking device 3. Top cover 11. Evaporation hole 21. Connecting post 22. Spring 23. Spring buckle 24. Hot fuse. Detailed Implementation

[0030] To deepen the understanding of this utility model, it will be further described in detail below with reference to embodiments and accompanying drawings. These embodiments are only for explaining this utility model and do not constitute a limitation on the scope of protection of this utility model. Embodiment 1

[0031] As shown in Figures 1-8, an instantaneous heat release device is installed in a battery pack composed of battery cells. The arc-shaped heat dissipation body 1 is made of metal, possessing good thermal conductivity to quickly transfer heat generated on the sides of the battery cells and simultaneously preheat the internal liquid. The top cover 3 is made of high-strength plastic. The liquid filled inside the evaporation hole 11 is a mixture of water and ethanol. The hot fuse 24 is a bismuth-tin alloy with a melting point of 90℃.

[0032] When installing this device, first, install the spring 22 in the specially provided spring mounting hole on the lower surface of the upper cover 3. The connecting post 21 passes through the spring 22, and the top of the connecting post 21 is fixed to the lower surface of the upper cover 3.

[0033] Next, the spring clip 23 is installed in the countersunk hole on the upper surface of the arc-shaped heat dissipation body 1. Then, by pressing, the spring clip 23 engages with the connecting post 21.

[0034] Usage process: When the battery pack experiences thermal runaway, the rising temperature causes the thermal fuse 24 to break. After the thermal fuse breaks, the spring clip 23 opens under its own elastic force, so that the protrusion on the inside of the spring clip no longer locks the lower end of the connecting post.

[0035] When the spring clip 23 separates from the connecting post 21, the upper cover 3 will detach from the upper surface of the arc-shaped heat dissipation body 1 under the action of the spring 22, thereby causing the liquid heat dissipation material inside the arc-shaped heat dissipation body 1 to evaporate rapidly, achieving emergency instantaneous heat dissipation in case of thermal runaway.

[0036] After the instantaneous heat dissipation is complete, the main heat dissipation system of the battery cell, such as a liquid cooling system or other air-cooling systems, then intervenes to minimize the losses caused by thermal runaway. Example 2

[0037] At this point, the hot fuse 24 is no longer installed, and the rest of the parts are the same as in Example 1.

[0038] During use, the internal heat rapidly vaporizes the liquid inside the evaporation hole 11, thereby generating significant pressure. Under this pressure, the connecting post 21 separates from the spring clip 23, causing the spring 22 to activate.

[0039] Under the action of spring 22, the top cover will open, thereby releasing the gas generated in the evaporation hole 11 and providing sufficient space for the unvaporized liquid in the evaporation hole 11 to complete the vaporization, thereby realizing the instantaneous release of internal heat.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A device for instantaneous heat release in the event of thermal runaway of a battery pack, characterized in that, The device includes an arc-shaped heat dissipation body, a top cover, and a locking device for connecting the arc-shaped heat dissipation body and the top cover. The arc-shaped heat dissipation body has several evaporation holes inside, which are countersunk holes and filled with liquid. The top cover abuts against the top of the arc-shaped heat dissipation body. When the locking device tightly connects the arc-shaped evaporation body and the top cover, the lower surface of the top cover abuts against the opening of the evaporation hole. When the locking device no longer tightly connects the arc-shaped evaporation body and the top cover, the lower surface of the top cover no longer abuts against the opening of the evaporation hole.

2. The instantaneous heat release device for battery pack thermal runaway fault according to claim 1, characterized in that... The locking device includes a connecting post, a spring, a spring clip, and a hot-melt wire; the top of the connecting post is connected to the lower surface of the upper cover, the lower surface of the spring clip is connected to the arc-shaped heat dissipation body, and a spring is provided between the connecting post and the spring clip; the spring clip is U-shaped, and the inner side of the spring clip has opposing protrusions, and a hot-melt wire is provided below the protrusions. The protrusions are used to engage the lower end of the connecting post, and the hot-melt wire is used to limit the opening size of the spring clip.

3. The instantaneous heat release device for battery pack thermal runaway fault according to claim 1, characterized in that... The locking device includes a connecting post, a spring, and a spring buckle; the top of the connecting post is connected to the lower surface of the upper cover, the lower surface of the spring buckle is connected to the arc-shaped heat dissipation body, and a spring is provided between the connecting post and the spring buckle; the spring buckle is U-shaped, and the inner side of the spring buckle is provided with opposing protrusions. In the normal state of the spring buckle, the spring buckle is engaged with the lower end of the connecting post.

4. A device for instantaneous thermal energy release in the event of thermal runaway of a battery pack according to any one of claims 1-3, characterized in that... The lower surface of the upper cover is provided with a number of spring mounting holes, the size of which matches the size of the spring; the upper surface of the arc-shaped heat dissipation body is provided with countersunk holes that match the spring mounting holes, the diameter of which matches the maximum outer dimensions of the spring buckle.

5. The instantaneous heat release device for battery pack thermal runaway fault according to claim 4, characterized in that... The arc-shaped heat dissipation body has several evaporation holes inside, and the liquid inside the evaporation holes is one or a mixture of water, ethanol, ethylene glycol or glycerol.

6. The instantaneous heat release device for battery pack thermal runaway fault according to claim 4, characterized in that... The depth of the evaporation hole is 3 / 4 to 2 / 3 of the overall height of the arc-shaped heat dissipation body.

7. The instantaneous heat release device for battery pack thermal runaway fault according to claim 2, characterized in that... The melting point of the hot melt wire is 80-95℃.

8. The instantaneous heat release device for battery pack thermal runaway fault according to claim 4, characterized in that... Its characteristics are, The spring clip is made of spring steel, with a rounded bottom and a flat top.

9. The instantaneous heat release device for battery pack thermal runaway fault according to claim 4, characterized in that... Its characteristics are, The lower surface of the top cover is coated with a high-temperature resistant silicone layer with a thickness of 0.1~0.5mm.

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