Battery pack structure capable of preventing thermal runaway

Abstract

The utility model provides a battery pack structure capable of preventing thermal runaway, which belongs to the technical field of new energy automobile power batteries and mainly comprises a battery cell box body, the battery cell box body comprises a box body bottom plate and box body side plates, battery cells are uniformly placed in the battery cell box body, anti-explosion valves are arranged on the battery cells and are directly connected with a smoke exhaust channel, and the smoke exhaust channel is communicated with the battery cell box body. The explosion-proof valve can be quickly opened when the battery cell is subjected to thermal runaway, and high-temperature smoke generated by thermal runaway is discharged out of the battery module through the smoke discharge channel, so that the temperature in the battery module is reduced, and the risk of thermal runaway is reduced; the adjacent battery cells in the battery cell box body are isolated by the battery cell filling material, the battery cell filling material adopts basalt fiber cotton, the basalt fiber cotton is a combustion gap for enabling thermal runaway to flow out between the adjacent battery cells, and thermal runaway is controlled on the independent battery cell, so that a thermal runaway chain reaction is prevented, and the service life of the battery cell box body is prolonged. Therefore, the battery cell with thermal runaway damages the other safe battery cells, and greater safety accidents are caused.

Description

Technical Field

[0001] The utility model belongs to the technical field of power batteries for new energy vehicles, and particularly relates to a battery pack structure for preventing thermal runaway. Background Art

[0002] Battery thermal runaway refers to the phenomenon that the battery generates a sharp increase in heat under specific conditions (such as overcharging, over-discharging, internal short circuit, external high temperature, etc.), resulting in a rapid rise in the internal temperature of the battery, and then triggering a series of chemical reactions, which may ultimately lead to fire or explosion; in the traditional module design, the battery cells are closely attached to each other. Once a certain battery cell undergoes thermal runaway, the heat and flame generated by it will quickly spread to adjacent battery cells, causing thermal runaway of the entire module or even the entire battery pack, and then triggering serious safety accidents. Content of the Utility Model

[0003] The utility model provides a battery pack structure for preventing thermal runaway to solve the technical problem of the thermal runaway chain phenomenon caused by the close attachment of battery cells in the prior art.

[0004] In order to achieve the above object, the utility model adopts the following technical scheme:

[0005] A battery pack structure for preventing thermal runaway includes a box bottom plate and box side plates. The box bottom plate is arranged at the bottom of the box side plates. The box bottom plate and the box side plates form a battery cell box body. Battery cells are placed in the battery cell box body. An explosion-proof valve is arranged on the battery cells, and the explosion-proof valve is connected to a smoke exhaust channel. The adjacent battery cells in the battery cell box body are separated from each other by battery cell filling materials.

[0006] The battery cell box body is divided into two parts by a second partition board.

[0007] First partition boards are arranged on both sides of the second partition board. The first partition boards are vertically and evenly arranged perpendicular to the second partition board. Heating films are installed on the first partition boards. The first partition boards and the second partition board divide the battery cell box body into several battery cell accommodation areas, and the battery cells are arranged in the battery cell accommodation areas.

[0008] Positioning brackets are arranged on both sides of the second partition board.

[0009] Positioning brackets are fixed on the box side plates. The positioning brackets on the second partition board correspond to the positioning brackets on the box side plates one by one.

[0010] The battery cells are fixed on the battery cell box body through the positioning brackets.

[0011] The positioning brackets correspond to the positive and negative electrodes of the battery cells.

[0012] Basalt fiber cotton is filled between the adjacent battery cells, and the basalt fiber cotton serves as the battery cell filling material.

[0013] A liquid cooling plate is welded to the bottom surface of the box body bottom plate.

[0014] A heat-conducting structural adhesive is sprayed between the liquid cooling plate and the battery cells.

[0015] Compared with the prior art, the utility model has the following beneficial effects:

[0016] The battery pack structure for preventing thermal runaway disclosed by the utility model, wherein the battery cell box body forms a firm outer shell through the box body bottom plate and the side plates, providing physical protection for the battery cells; the explosion-proof valve is connected to the smoke exhaust channel. When thermal runaway occurs in the battery cells, the explosion-proof valve automatically opens, and the smoke exhaust channel connected to the explosion-proof valve can quickly discharge the high-temperature smoke and gas outside the battery pack, helping to reduce the temperature around the battery module, reducing the risk of thermal runaway of the battery cells, preventing explosion, and protecting the safety of personnel and vehicles; the battery cell filler arranged between the battery cells effectively isolates adjacent battery cells, effectively avoiding the phenomenon that when thermal runaway occurs in a battery cell, it causes a thermal runaway chain reaction to other adjacent battery cells, thereby damaging the remaining safe battery cells, and avoiding the occurrence of a larger safety accident. Through multi-level thermal management design, physical isolation measures, intelligent heating system and efficient cooling mechanism, a highly safe, reliable and stable-performance battery pack solution is formed, effectively preventing the occurrence of thermal runaway and ensuring the use safety of electric vehicles.

[0017] Furthermore, the second partition divides the battery cell box body into two parts. Combined with the vertical and uniform arrangement of the first partition, a multi-layer protection structure is formed, which helps to manage and control the heat flow direction, reduce local overheating, and at the same time increase the structural stability of the battery pack.

[0018] Furthermore, the heating film installed on the first partition can preheat the battery cells in a low-temperature environment, promote the uniformity of the internal temperature of the battery cells, prevent performance degradation or damage caused by large temperature differences at the initial stage of charging or use, and extend the service life of the battery.

[0019] Furthermore, the use of the positioning bracket not only ensures the stable installation of the battery cells, reduces the displacement and damage of the battery cells caused by vibration, but also simplifies the electrical connection and maintenance by corresponding arrangement with the positive and negative electrodes of the battery cells, and at the same time improves the thermal isolation effect between the battery cells.

[0020] Furthermore, the battery cells are isolated by the battery cell filling material. Not only physically isolates the battery cells and avoids the spread of thermal runaway, but also the battery cell filling material is basalt fiber cotton, and the high-temperature resistance characteristic of basalt fiber cotton can effectively prevent the spread of fire, further reducing the risk of thermal runaway and improving the overall safety of the battery pack.

[0021] Furthermore, the cell filling material is basalt fiber cotton, which has high heat resistance and can effectively isolate the spread of fire from the out-of-control cells to the remaining safe cells, effectively reducing the risk of the chain reaction of cell thermal runaway.

[0022] Furthermore, the liquid cooling plate provided on the bottom surface of the box body bottom plate can respond quickly during cell thermal runaway, perform heat exchange, prevent cell heat spread, effectively reduce the risk of cell thermal runaway, and improve safety.

[0023] Furthermore, the thermally conductive structural adhesive sprayed between the liquid cooling plate and the cell forms an efficient heat conduction channel between the cell and the liquid cooling plate, further enhancing the heat conduction efficiency, ensuring the efficient operation of the thermal management system, reducing the risk of thermal runaway, and improving the reliability and safety of the battery system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic diagram of the battery pack structure;

[0025] Figure 2 is a schematic diagram of the cell box structure;

[0026] Figure 3 is a schematic diagram of the liquid cooling plate installation;

[0027] Figure 4 is a schematic diagram of the heating film installation;

[0028] Figure 5 is a connection diagram of the explosion-proof valve and the smoke exhaust channel.

[0029] Number description: 1. Cell box; 2. Box body bottom plate; 3. Box body side plate; 4. Positioning bracket; 5. Liquid cooling plate; 6. Cell; 7. Explosion-proof valve; 8. Cell filling material; 9. Heating film; 10. Smoke exhaust channel; 11. First partition; 12. Second partition. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] To further understand the content of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments are only for explaining the present invention and not for limiting it.

[0031] See Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 and Figure 5, there is a second partition 12 inside the battery cell box 1. The second partition 12 divides the battery cell box 1 into two parts. The first partitions 11 are evenly arranged on both sides of the second partition 12. The first partitions 11 are perpendicular to the second partition 12. The first partitions 11 and the second partition 12 evenly divide the battery cell box 1 into multiple independent battery cell 6 accommodation areas; a heating film 9 is installed on each first partition 11, as Figure 4 shown; positioning brackets 4 are installed on both sides of the second partition 12, and positioning brackets 4 are also provided on the side plate of the box body 3 that is parallel to the second partition 12. The positioning brackets 4 on the box body side plate 3 correspond to the positioning brackets 4 on the second partition 12; the battery cells 6 are fixedly hung on the box body side plate 3 through the positioning brackets 4. There is a gap between adjacent battery cells 6, and a battery cell filling material 8 is filled in this gap; an explosion-proof valve 7 is provided on each battery cell 6, and all the explosion-proof valves 7 are connected to a smoke exhaust channel 10, as Figure 5 shown, Figure 5 only a few of the explosion-proof valves 7 are taken as examples for the connection with the smoke exhaust channel 10; a liquid cooling plate 5 is further provided on the bottom surface of the box body bottom plate 2 of the battery cell box 1, and the liquid cooling plate 5 is integrated with the battery cell box 1.

[0032] A battery pack structure for preventing thermal runaway and its implementation method:

[0033] The cross beams and longitudinal beams obtained by extrusion of 6-series aluminum alloy materials are used for the box body bottom plate 2 of the battery cell box 1. The cross beams and longitudinal beams are perpendicularly welded and fixed to ensure sufficient mechanical strength of the box body while reducing the weight;

[0034] The bottom surface of the box body bottom plate 2 is integrated with the liquid cooling plate 5 by welding the liquid cooling plate 5 to the cross beams and longitudinal beams of the box body bottom plate 2, so that the liquid cooling plate 5 is integrated with the battery cell module, getting closer to the battery module better and realizing efficient heat exchange; a heat-conducting structural adhesive is sprayed on the upper layer of the liquid cooling plate 5, and the heat-conducting structural adhesive forms an efficient heat conduction channel between the battery cells 6 and the liquid cooling plate 5, further increasing the heat exchange efficiency of the liquid cooling plate 5 to ensure the temperature stability inside the battery module and reduce the risk of thermal runaway of the battery cells 6;

[0035] A second partition 12 is arranged at the middle position inside the battery cell box body 1. The second partition 12 divides the battery cell box body 1 into two parts. The first partitions 11 are evenly arranged perpendicular to the second partition 12 on both sides of the second partition 12. The first partitions 11 and the second partition 12 evenly divide the interior of the battery cell box body 1 into eight accommodation areas for the battery cells 6. A heating film 9 is installed on the first partition 11. The heating film 9 can ensure that the battery cells 6 of the battery module can operate normally under low-temperature conditions. Positioning brackets 4 are arranged on two side plates of the box body side plate 3 of the battery cell box body 1 that are parallel to the second partition 12 and on both sides of the second partition 12. And the positioning brackets on the box body side plate 3 and the second partition 12 correspond to each other in pairs. The positioning brackets 4 are made of a composite material formed by PC and ABC injection molded parts. The battery cells 6 are fixedly arranged in the box body one by one through the positioning brackets on the box body side plate 3. Each positioning bracket 4 is designed with a fixed position corresponding to the positive and negative electrodes of the battery cell 6. After the battery cells 6 are fixed, the positive and negative electrodes of the battery cells 6 are welded and fixed to the positioning brackets 4. The thermal conductive structural adhesive on the upper layer of the liquid cooling plate 5 also further fixes the battery cells 6 to ensure the stable position of the battery cells 6 under the conditions of vehicle driving or vibration. The battery cells 6 are divided into eight groups and stacked in two rows according to the partitions in the battery cell box body 1. The modules of the eight groups of double-row battery cells 6 after stacking are fixed in the battery cell box body 1 through the positioning brackets 4.

[0036] After the battery cells 6 are fixed, there are small gaps between adjacent battery cells 6. A battery cell filling material 8 is filled in this gap and the battery cell filling material 8 is pasted on the battery cells 6. The battery cell filling material 8 is basalt fiber cotton. The basalt fiber cotton can reach 1200°C when heated. Under the condition of heating for 8 minutes, it can still ensure the integrity of the structure. It can isolate the heat generated by the battery cell during thermal runaway and effectively absorb heat, isolating the fire of the thermally out-of-control battery cell from spreading to adjacent battery cells and reducing the possibility of thermal runaway chain reaction.

[0037] An explosion-proof valve 7 is arranged on the battery cell 6. The explosion-proof valve 7 is made of a composite material formed by brass, PET hot-pressed material and soft mica sheet and has high high-temperature and high-pressure resistance characteristics. The explosion-proof valve 7 is directly connected to a smoke exhaust channel 10. The material of the smoke exhaust channel 10 is made of special copper that can withstand high temperatures to ensure that the structure remains intact under high-temperature environments. When the battery cell 6 undergoes thermal runaway and generates high temperature, the explosion-proof valve 7 quickly opens, and the high-temperature gas quickly discharges through the chimney channel and the smoke exhaust channel of the explosion-proof valve 7, effectively reducing the internal temperature and pressure and reducing the risk of thermal runaway chain reaction.

[0038] When a battery cell 6 experiences thermal runaway, it generates heat and the temperature can reach over 500°C. The battery cell fillers 8 between the battery cells 6 control the damage to the single battery cell 6 experiencing thermal runaway. At the same time, the specially made copper smoke exhaust channel 10 is directly connected to the explosion-proof valve 7, which can quickly open the explosion-proof valve 7 at the early stage of thermal runaway, release the internal pressure and heat of the battery pack, reduce the accumulation of high-temperature gas, effectively control the spread of the thermal runaway of the battery cell 6, and protect the structural integrity of the battery pack and the safety of the surrounding environment.

[0039] Preferably, a layer of heat-conducting structural adhesive is sprayed on the upper layer of the liquid cooling plate 5 to form a uniform heat-conducting layer on the upper layer of the liquid cooling plate 5. The formed high-heat layer serves as a heat transfer channel between the battery cell 6 and the liquid cooling plate 5. When the battery cell 6 has thermal runaway, the heat exchange efficiency of the liquid cooling plate 5 can be further accelerated, thereby reducing the temperature gradient inside the battery pack and improving the heat dissipation effect of the battery pack. The application of heat-conducting structural adhesive can reduce thermal resistance and energy loss during heat transfer, thereby improving the heat transfer efficiency of the entire battery pack. It not only helps to extend the service life of the battery and improve its performance stability, but also accelerates the cooling efficiency when the battery cell 6 has thermal runaway, reducing the risk of thermal runaway spreading to other safe batteries 6.

[0040] Preferably, a liquid cooling plate 5 is welded on the bottom plate 2 of the battery box 1, and the liquid cooling plate 5 is connected to an external cooling system through a pipeline to form a closed cooling circuit; when the temperature of the battery cell 6 rises abnormally due to thermal runaway, the coolant in the liquid cooling plate 5 responds quickly and takes away the heat of the battery cell 6 through heat exchange. The liquid cooling plate 5 can improve the regional cooling and heat exchange effect between the battery cells 6, effectively prevent the heat spread of the battery cells 6, ensure that the temperature of each battery cell 6 in the battery pack is more uniform, reduce local overheating, and reduce the risk of thermal runaway of the battery cell 6, which is crucial to maintaining the overall stability of the battery pack and avoiding thermal runaway.

[0041] Preferably, a heating film 9 is installed on the first partition 11 in the battery box 1. The heating film 9 can provide evenly distributed heat, directly acting on the surface of the battery cell 6 and the first partition 11, which helps to increase the temperature of the battery cell 6 in a low temperature environment, ensure the temperature consistency inside the battery module, and reduce thermal runaway of the battery cell 6 caused by temperature differences.

[0042] In summary, this embodiment constructs a highly safe and reliable electric vehicle power battery pack structure by comprehensively applying explosion-proof valves 7, smoke exhaust channels 10, high-temperature resistant battery cell filling materials 8, high-efficiency liquid cooling technology, namely liquid cooling plates 5, and thermally conductive structural adhesive sprayed on the liquid cooling plates 5, which significantly reduces the risk of thermal runaway of the battery cells and ensures the safety of the vehicle and passengers.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: it is still possible to modify the specific implementation manners of the present invention or make equivalent substitutions, and any modification or equivalent substitution that does not depart from the spirit and scope of the present invention shall be covered by the protection scope of the claims of the present invention.

Claims

1. A battery pack structure for preventing thermal runaway, characterized in that: The invention comprises a box bottom plate (2) and a box side plate (3), wherein the box bottom plate (2) is arranged at the bottom of the box side plate (3), the box bottom plate (2) and the box side plate (3) form a battery box (1), a battery cell (6) is placed in the battery box (1), an explosion-proof valve (7) is arranged on the battery cell (6), the explosion-proof valve (7) is connected to a smoke exhaust channel (10), and adjacent battery cells (6) in the battery box (1) are isolated from each other by battery cell filling materials (8).

2. A battery pack structure for preventing thermal runaway according to claim 1, characterized in that: The battery box (1) is divided into two parts by a second partition (12) inside the battery box (1).

3. A battery pack structure for preventing thermal runaway according to claim 2, characterized in that: A first partition (11) is arranged on both sides of the second partition (12); the first partition (11) is evenly arranged perpendicular to the second partition (12); a heating film (9) is installed on the first partition (11); the first partition (11) and the second partition (12) divide the battery box (1) into a plurality of battery accommodating areas, wherein the battery cells (6) are arranged in the battery accommodating areas.

4. A battery pack structure for preventing thermal runaway according to claim 3, characterized in that: Positioning brackets (4) are arranged on both sides of the second partition plate (12).

5. A battery pack structure for preventing thermal runaway according to claim 4, characterized in that: A positioning bracket (4) is fixed on the box side plate (3), and the positioning bracket on the second partition plate (12) corresponds one-to-one to the positioning bracket on the box side plate (3).

6. A battery pack structure for preventing thermal runaway according to claim 5, characterized in that: The battery cell (6) is fixed on the battery cell box (1) via a positioning bracket (4).

7. A battery pack structure for preventing thermal runaway according to claim 6, characterized in that: The positioning bracket (4) corresponds to the positive and negative electrodes of the battery core (6).

8. The battery pack structure for preventing thermal runaway according to claim 1, characterized in that: Basalt fiber cotton is filled between adjacent battery cells (6), and the basalt fiber cotton serves as the battery cell filling material (8).

9. A battery pack structure for preventing thermal runaway according to claim 1, characterized in that: A liquid cooling plate (5) is welded to the bottom surface of the box bottom plate (2).

10. A battery pack structure for preventing thermal runaway according to claim 1, characterized in that: Thermally conductive structural glue is sprayed between the liquid cooling plate (5) and the battery core (6).

Images