Passive fire extinguishing structure for preventing lithium battery from catching fire during charging

Abstract

The utility model discloses a passive fire extinguishing structure for preventing lithium battery charging ignition, which relates to the technical field of batteries, and comprises a box body and at least one battery accommodated in the box body, and a heat dissipation plate is arranged on the side of the battery. The heat dissipation plate comprises a base plate and a first plate body facing the battery side, the first plate body is provided with a bent part, the base plate is connected with the edge of the first plate body, and a fire extinguishing patch is arranged on the first plate body. The utility model aims to provide the passive fire extinguishing structure for preventing the lithium battery from catching fire during charging, which has a good thermal runaway inhibiting effect and a buffering capability.

Description

Technical Field

[0001] The utility model belongs to the technical field of batteries, and in particular relates to a passive fire extinguishing structure for preventing and controlling lithium battery fire during charging. Background Art

[0002] With the continuous improvement of the energy density of battery cells, the need to improve the safety of battery packs is becoming increasingly urgent. Battery packs are prone to thermal runaway during use. Thermal runaway refers to the cumulative enhancement of current and battery temperature during constant voltage charging, which gradually damages and causes fires. Once a fire occurs, it will cause irreparable losses if it is not quickly extinguished. At present, the market has only made early warning actions for battery fires, and fire extinguishing actions still occur after the fire and require quick human response to extinguish the fire. However, due to the rapid spread of battery fires, the fire cannot be effectively controlled in the event of a delay in human fire extinguishing response.

[0003] Prior art includes an invention patent entitled Passive fire extinguishing device and battery pack, the publication number of which is WO2022012449A1. This invention relates to a passive fire extinguishing device and a battery pack. The passive fire extinguishing device includes a fire extinguishing device shell, which surrounds a sealed space, in which a fire extinguishing agent and compressed gas are arranged, wherein the fire extinguishing device shell is used to be arranged on the end covers of multiple battery modules or the safety valves of multiple battery cells in multiple battery modules, and when a battery cell has thermal runaway, the end cover or the safety valve opens, the fire extinguishing device shell ruptures, and the fire extinguishing agent is sprayed onto the end cover or the safety valve. However, this invention is prone to case rupture, causing chain battery explosions. Summary of the invention

[0004] The utility model aims to provide a passive fire extinguishing structure for preventing and controlling lithium battery charging fire, which has good thermal runaway suppression effect and buffering capacity.

[0005] The technical solution adopted by the utility model to achieve the above-mentioned purpose is:

[0006] A passive fire extinguishing structure for preventing and controlling lithium battery fires during charging, comprising a box body and at least one battery housed in the box body, a heat sink is provided on the side of the battery, the heat sink comprises a substrate and a first plate body facing the battery side, the first plate body has a bending portion, the substrate and the first plate body are connected at the edge, and a fire extinguishing sticker is provided on the first plate body.

[0007] Since a heat sink corresponding to the battery is provided in the box, the heat sink can be arranged around the battery or arranged in an array at intervals, and the position of the battery can be fixed by the heat sink, and the heat sink has a substrate and a first plate body, wherein the first plate body has a plurality of bending parts, and since the substrate and the first plate body are only connected at the edge, there will be a certain gap between the substrate and the first plate body, and a coolant or airflow can flow inside the gap, and the coolant or airflow can be used to absorb or transfer the heat emitted during the charging process of the battery in the box, thereby preventing or reducing the occurrence of lithium battery fire during the charging process, and the first plate body has a bending part, and most of the cooling or airflow will flow from the bending part, and the design of the bending part will make the surface area larger, thereby improving the efficiency of transferring excess heat inside the box. It should be noted that in the present utility model, the gap formed between the substrate and the first plate body can have a variety of forms, including but not limited to the following situations: the gap between the substrate and the first plate body is formed by the tension of the first plate body, that is, a gap with an arc is formed between the first plate body and the substrate; the substrate and the first plate body are arranged in parallel and at intervals. The gap setting between the substrate and the first plate body can not only improve the balance of the refrigerant or airflow flow speed within each bend, but also achieve the heat dissipation balance of the heat sink, prevent the situation that only part of the bend is heat exchanged during the battery charging process in the box, and increase the refrigerant or airflow flow surface area in the heat sink, thereby improving the heat exchange efficiency. It should be further explained that, through the setting of the gap, when the battery in the box is in thermal runaway during the charging process, the gap and the bend will be compressed to absorb the impact force, preventing the impact force from damaging the box or the substrate, and at this time, the fire extinguishing sticker on the first plate body will release the fire extinguishing agent when exposed to high temperature or open flames, thereby preventing the battery in the box from causing chain explosions and the fire from spreading to the outside.

[0008] It should be noted that electronic components are arranged in the box body. Furthermore, a fire extinguishing sticker is arranged on the inner wall of the box base, and the fire extinguishing sticker is arranged around the electronic components.

[0009] Furthermore, the heat sink is arranged in the box body, that is, the base plate is connected to the box body, and the gap between the base plate and the first plate body is connected to the tube body to achieve the circulation of the coolant or airflow.

[0010] Furthermore, the battery adopts a single-cell battery.

[0011] Furthermore, the fire extinguishing patch uses a perfluorohexanone fire extinguishing patch. When the fire extinguishing patch with the above coating is used, it can be achieved that when the perfluorohexanone fire extinguishing patch is exposed to a temperature of 80-130°C and / or an open flame environment, it can break and vaporize to release the fire extinguishing material to achieve the purpose of cooling and / or fire prevention and / or fire extinguishing, thereby suppressing thermal runaway, actively cooling, and actively extinguishing fires; in addition, the use of perfluorohexanone as a fire extinguishing agent greatly reduces the vaporization loss of perfluorohexanone in the microcapsule under normal conditions, and has a long service life. Among them, perfluorohexanone vaporizes quickly after extinguishing the fire, is non-conductive, does not pollute the protected object, and will not cause damage to financial, archival materials and precision facilities. It can greatly reduce the post-fire losses, especially when this device is set up in an archive room or storage room.

[0012] According to an embodiment of the utility model, the heat dissipation plate is disposed through the box body.

[0013] Through the above design, the refrigerant or airflow flowing in the gap formed by the heat sink and the first plate body can enter the heat sink from the outside of the box, which is beneficial to the utilization of the internal and external space of the box, and the through-setting of the heat sink can improve the heat sink's effect of discharging the internal medium in the event of thermal runaway of the battery, thereby improving the ability to absorb impact force; and because the substrate in the heat sink is fixedly connected to the box, the structural strength of the box can be effectively improved, and part of the internal structure that improves the structural strength can be removed to increase the available space inside the box.

[0014] According to an embodiment of the utility model, a guide channel is provided on the outer side of the box body through which the heat dissipation plate penetrates.

[0015] The guide channel is used to guide the medium entering the gap between the substrate and the first plate body.

[0016] Furthermore, the medium is a gaseous medium.

[0017] Furthermore, a flow guiding device is provided in the flow guiding channel to increase the flow velocity of the medium.

[0018] Furthermore, multiple passive fire extinguishing structures for preventing lithium battery charging and catching fire can be connected end to end to achieve multiple utilization of the diversion medium.

[0019] According to one embodiment of the utility model, a buffer assembly is provided between two adjacent bending parts, and the buffer assembly includes a first cavity and a second cavity. The first cavity and the second cavity are connected through a first vent hole, and the second cavity is connected to a first vent pipe, and the first vent pipe is connected to the space inside the box.

[0020] When the battery has thermal runaway, the internal air pressure increases and impacts the heat sink. At this time, the first vent pipe will absorb part of the high-pressure gas into the second cavity, and then discharge the gas into the first cavity through the first vent hole between the first cavity and the second cavity. Through the above design, the impact effect of gas expansion on the first plate and substrate after thermal runaway of the battery can be reduced.

[0021] Furthermore, the first cavity and the second cavity are made of flexible material.

[0022] Furthermore, the buffer assembly is provided with a protruding bent portion. More specifically, the first cavity is provided with a protruding bent portion. Through the above design, since the gas in the first cavity can be compressed, the flatness of the heat sink can be achieved when the battery contacts the heat sink, thereby improving the heat dissipation effect of the battery during charging and preventing the heat sink from dissipating unevenly during the heat dissipation process.

[0023] According to an embodiment of the present invention, the bent portion is connected to the first cavity through the second vent hole.

[0024] It should be noted that when the medium flowing in the bend is gas, the bend can be connected to the first cavity through the second vent. At this time, when the battery has thermal runaway, the gas pressure in the first cavity increases and part of the gas will enter the bend through the second vent. When the battery dissipates heat in the box during charging, causing the air pressure in the first cavity to increase, and at this time the gas medium in the first cavity has a high heat, part of the gas medium can be discharged into the bend through the second vent, and direct heat discharge can be achieved through the flow of the medium in the bend, which is conducive to improving the control of the heat in the box. After the battery temperature is balanced, the second vent is used to achieve the balance of the air pressure in the box with the outside world.

[0025] According to one embodiment of the utility model, at least one third cavity and a fourth cavity corresponding to the third cavity are provided in the first cavity, the third cavity and the fourth cavity are connected through a third vent hole, the fourth cavity is connected with a second vent pipe, and the second vent pipe is connected with the first cavity.

[0026] According to an embodiment of the utility model, the bent portion is connected to the third cavity through the fourth vent hole.

[0027] Through the above design, the ability of the buffer component to regulate the thermal runaway of the battery in the box can be further improved, and the buffering effect of the buffer component can be further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of a passive fire extinguishing structure for preventing and controlling lithium battery charging fires;

[0029] Figure 2is a three-dimensional schematic diagram of a heat sink;

[0030] Figure 3 This is a schematic diagram of the cooperation between the heat sink and the buffer assembly.

[0031] Figure numbers: box body 1, battery 2, heat sink 3, substrate 31, first plate body 32, bending portion 33, guide channel 4, buffer assembly 5, first cavity 51, second cavity 52, first ventilation hole 53, first ventilation pipe 54, third cavity 55, fourth cavity 56, third ventilation hole 57, second ventilation pipe 58, fourth ventilation hole 59. DETAILED DESCRIPTION

[0032] The technical solution of the utility model is further described in detail below in conjunction with specific implementation methods and drawings:

[0033] Embodiment 1:

[0034] like Figure 1 and 2 As shown, a passive fire extinguishing structure for preventing and controlling a lithium battery from catching fire during charging includes a box body 1 and at least one battery 2 accommodated in the box body 1, a heat sink 3 is provided on the side of the battery 2, the heat sink 3 includes a substrate 31 and a first plate body 32 facing the battery 2 side, the first plate body 32 has a bending portion 33, the substrate 31 and the first plate body 32 are connected at the edges, and a fire extinguishing sticker is provided on the first plate body 32.

[0035] Since a heat sink 3 corresponding to the battery 2 is provided in the box body 1, the heat sink 3 can be arranged around the battery 2 or arranged in an array at intervals. The position of the battery 2 can be fixed by the heat sink 3, and the heat sink 3 has a substrate 31 and a first plate body 32, wherein the first plate body 32 has a plurality of bending portions 33. Since the substrate 31 and the first plate body 32 are only connected at the edges, there will be a certain gap between the substrate 31 and the first plate body 32, and a coolant or airflow can flow inside the gap. The coolant or airflow can absorb or transfer the heat emitted during the charging process of the battery 2 in the box body 1, thereby preventing or reducing the occurrence of fire of the lithium battery 2 during the charging process. In addition, there is a bending portion 33 on the first plate body 32, and most of the cooling or airflow will flow from the bending portion 33. The design of the bending portion 33 will make the surface area larger, thereby improving the efficiency of transferring excess heat inside the box body 1. It should be noted that in the present invention, the gap formed between the substrate 31 and the first plate body 32 can have various forms, including but not limited to the following situations: the gap between the substrate 31 and the first plate body 32 is formed by the tension of the first plate body 32, that is, an arc-shaped gap is formed between the first plate body 32 and the substrate 31; the substrate 31 and the first plate body 32 are arranged in parallel and spaced apart. The gap setting between the substrate 31 and the first plate body 32 can not only improve the balance of the refrigerant or airflow flow speed within each bending portion 33, but also achieve the heat dissipation balance of the heat sink 3, prevent the situation that only part of the bending portion 33 performs heat exchange during the charging process of the battery 2 in the box body 1, and can increase the refrigerant or airflow flow surface area in the heat sink 3, thereby improving the heat exchange efficiency. It should be further explained that, through the setting of the gap, when the battery 2 in the box body 1 has thermal runaway during charging, the gap and the bent portion 33 will be compressed to absorb the impact force, thereby preventing the impact force from causing damage to the box body 1 or the substrate 31. At this time, the fire extinguishing sticker on the first plate body 32 will release the fire extinguishing agent when exposed to high temperature or open flame, thereby preventing the battery 2 in the box body 1 from causing a chain explosion and the fire from spreading to the outside.

[0036] It should be noted that electronic components are arranged in the box 1. Furthermore, a fire extinguishing sticker is arranged on the inner wall of the box base, and the fire extinguishing sticker is arranged around the electronic components.

[0037] Furthermore, the heat sink 3 is disposed in the box body 1, that is, the base plate 31 is connected to the box body 1, and the gap between the base plate 31 and the first plate body 32 is connected to the pipe body to achieve the circulation of the coolant or airflow.

[0038] Furthermore, the battery 2 is a single-cell battery.

[0039] Furthermore, the fire extinguishing patch uses a perfluorohexanone fire extinguishing patch. When the fire extinguishing patch with the above coating is used, it can be achieved that when the perfluorohexanone fire extinguishing patch is exposed to a temperature of 80-130°C and / or an open flame environment, it can break and vaporize to release the fire extinguishing material to achieve the purpose of cooling and / or fire prevention and / or fire extinguishing, thereby suppressing thermal runaway, actively cooling, and actively extinguishing fires; in addition, the use of perfluorohexanone as a fire extinguishing agent greatly reduces the vaporization loss of perfluorohexanone in the microcapsule under normal conditions, and has a long service life. Among them, perfluorohexanone vaporizes quickly after extinguishing the fire, is non-conductive, does not pollute the protected object, and will not cause damage to financial, archival materials and precision facilities. It can greatly reduce the post-fire losses, especially when this device is set up in an archive room or storage room.

[0040] The materials used for the fire extinguishing patches in this case include but are not limited to the following sources: materials disclosed in the invention patent with publication number CN114736554A entitled An environmentally friendly fire retardant coating and its preparation method, materials disclosed in the invention patent with publication number CN114748830A entitled A perfluorohexanone microcapsule fire extinguishing material and its preparation method, etc.

[0041] The heat dissipation plate 3 is disposed through the box body 1 .

[0042] Through the above design, the refrigerant or airflow flowing in the gap formed by the heat sink 3 and the first plate body 32 can enter the heat sink 3 from the outside of the box body 1, which is beneficial to the utilization of the internal and external space of the box body 1, and the through-setting of the heat sink 3 can improve the discharge effect of the heat sink 3 in dealing with the internal medium of the battery 2 in the event of thermal runaway, thereby improving the absorption capacity of impact force; and because the substrate 31 in the heat sink 3 is fixedly connected to the box body 1, the structural strength of the box body 1 can be effectively improved, and part of the internal structure that improves the structural strength can be removed to increase the available space inside the box body 1.

[0043] The box body 1 is penetrated by the heat dissipation plate 3 and a guide channel 4 is arranged on the outside.

[0044] The guide channel 4 is used to guide the medium entering the gap between the base plate 31 and the first plate body 32 .

[0045] Furthermore, the medium is a gaseous medium.

[0046] Furthermore, a flow guiding device is provided in the flow guiding channel 4 to increase the flow velocity of the medium.

[0047] Furthermore, multiple passive fire extinguishing structures for preventing lithium battery charging and catching fire can be connected end to end to achieve multiple utilization of the diversion medium.

[0048] A buffer assembly 5 is provided between two adjacent bending portions 33 , and the buffer assembly 5 includes a first cavity 51 and a second cavity 52 . The first cavity 51 and the second cavity 52 are connected via a first vent hole 53 . The second cavity 52 is connected via a first vent pipe 54 , and the first vent pipe 54 is connected to the space inside the box body 1 .

[0049] When the battery 2 has thermal runaway, the internal air pressure increases and impacts the heat sink 3. At this time, the first vent pipe 54 will absorb part of the high-pressure gas into the second cavity 52, and then discharge the gas into the first cavity 51 through the first vent hole 53 between the first cavity 51 and the second cavity 52. ​​Through the above design, the impact effect of gas expansion on the first plate 32 and the substrate 31 after the battery 2 has thermal runaway can be reduced.

[0050] Furthermore, the first cavity 51 and the second cavity 52 are made of flexible material.

[0051] Furthermore, the buffer assembly 5 is provided with a protruding bent portion 33. More specifically, the first cavity 51 is provided with a protruding bent portion 33. Through the above design, since the gas in the first cavity 51 can be compressed, the flatness of the heat sink 3 can be achieved when the battery 2 contacts the heat sink 3, thereby improving the heat dissipation effect of the battery 2 during charging and preventing the heat sink 3 from dissipating unevenly during the heat dissipation process.

[0052] The bent portion 33 is connected to the first cavity 51 through the second vent hole.

[0053] It should be noted that when the medium flowing in the bend 33 is gas, the bend 33 can be connected to the first cavity 51 through the second vent hole. At this time, when the battery 2 has thermal runaway, the gas pressure in the first cavity 51 increases and part of the gas will enter the bend 33 through the second vent hole. When the battery 2 dissipates heat in the box 1 during charging, causing the air pressure in the first cavity 51 to increase, and at this time the gas medium in the first cavity 51 has a high heat, part of the gas medium can be discharged into the bend 33 through the second vent hole, and direct heat discharge is achieved through the flow of the medium in the bend 33, which is conducive to improving the control of the heat in the box 1. After the temperature of the battery 2 is balanced, the second vent hole is used to achieve the balance of the air pressure in the box 1 with the outside world.

[0054] The first cavity 51 is provided with at least one third cavity 55 and a fourth cavity 56 which is arranged in one-to-one correspondence with the third cavity 55 . The third cavity 55 and the fourth cavity 56 are connected via a third vent hole 57 . The fourth cavity 56 is connected with a second vent pipe 58 , and the second vent pipe 58 is connected with the first cavity 51 .

[0055] The bent portion 33 is connected to the third cavity 55 through the fourth vent hole 59 .

[0056] Through the above design, the ability of the buffer component 5 to regulate the thermal runaway of the battery 2 in the box 1 can be further improved, and the buffering effect of the buffer component 5 can be further improved.

[0057] The embodiments described above provide a detailed description of the technical solution of the utility model. It should be understood that the above is only a specific embodiment of the utility model and is not intended to limit the utility model. Any modifications, supplements or similar substitutions made within the scope of the principles of the utility model should be included in the protection scope of the utility model.

Claims

1. A passive fire extinguishing structure for preventing and controlling a lithium battery from catching fire during charging, comprising a box (1) and at least one battery (2) contained in the box (1), wherein a heat sink (3) is provided on the side of the battery (2), and characterized in that: The heat dissipation plate (3) comprises a substrate (31) and a first plate body (32) facing the battery (2); the first plate body (32) has a bent portion (33); the substrate (31) and the first plate body (32) are connected at their edges; and a fire extinguishing sticker is provided on the first plate body (32).

2. The passive fire extinguishing structure for preventing and controlling lithium battery charging fire according to claim 1, characterized in that: The heat dissipation plate (3) is arranged through the box body (1).

3. The passive fire extinguishing structure for preventing and controlling lithium battery charging fire according to claim 2, characterized in that: The box body (1) is penetrated by the heat dissipation plate (3) and is provided with a guide channel (4) on the outside.

4. The passive fire extinguishing structure for preventing and controlling lithium battery charging fire according to claim 1, characterized in that: A buffer assembly (5) is provided between two adjacent bent portions (33), the buffer assembly (5) comprising a first cavity (51) and a second cavity (52), the first cavity (51) and the second cavity (52) being connected via a first vent hole (53), the second cavity (52) being connected via a first vent pipe (54), and the first vent pipe (54) being connected to the space inside the box (1).

5. The passive fire extinguishing structure for preventing and controlling lithium battery charging fire according to claim 4, characterized in that: The bent portion (33) is in communication with the first cavity (51) via the second vent hole.

6. The passive fire extinguishing structure for preventing and controlling lithium battery charging fire according to claim 4, characterized in that: The first cavity (51) is provided with at least one third cavity (55) and a fourth cavity (56) arranged in one-to-one correspondence with the third cavity (55); the third cavity (55) and the fourth cavity (56) are connected via a third ventilation hole (57); the fourth cavity (56) is connected to a second ventilation pipe (58); and the second ventilation pipe (58) is connected to the first cavity (51).

7. The passive fire extinguishing structure for preventing and controlling lithium battery charging fire according to claim 6, characterized in that: The bent portion (33) is in communication with the third cavity (55) via a fourth vent hole (59).

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