A fireproof housing structure for a battery pack

Abstract

The present invention discloses a fireproof housing structure for a battery pack, including a bottom cover. On the upper end surface of the bottom cover, there are provided a number of battery module areas. Inside the battery module areas, there are a number of batteries. A fireproof structure is provided on the side of the battery. A cooling mechanism is provided between the batteries. Isolation mechanisms are provided on the outer sides of the battery module areas; The structure of the present invention is simple and reasonably designed. Through the alternately spaced expansion fireproof coatings and cooling parts on the side of the battery, the protection of the side of the battery is achieved. This structure can respond quickly when the battery is physically punctured. Through the carbonization of the expansion fireproof coating, the flame and heat are effectively isolated, the spread of the fire is delayed, and a physical barrier is created near the fire source, significantly increasing the safe evacuation time of the personnel in the vehicle and the rescue efficiency. In addition, the setting of the isolation mechanism reduces the influence of the flame and high temperature on other battery modules, improves the fireproof safety of the entire battery pack, and effectively reduces the risk of fire spread.

Description

Technical Field

[0001] The present invention relates to the technical field of power batteries, and particularly to a fireproof housing structure for a battery pack. Background Art

[0002] The power core of an electric vehicle is its battery pack, which is usually composed of multiple battery cells. The cells are configured in series or parallel to meet the required voltage and capacity requirements. Modern electric vehicle battery packs usually adopt lithium-ion battery technology, which has the characteristics of high energy density and long life. These battery packs not only need to withstand the electrochemical cycling load during normal use, but also need to cope with harsh conditions such as physical impact and temperature changes.

[0003] The optimization of battery pack design not only focuses on energy storage and output efficiency, but also attaches great importance to safety. For example, the battery management system (BMS) is the key to the safe operation of the battery. It monitors multiple indicators such as the charging state, temperature, and voltage of the battery to ensure that the battery operates within a safe range. In addition, modern electric vehicle battery packs usually integrate a thermal management system to keep the battery operating at the optimal working temperature, thereby improving efficiency and extending life.

[0004] Deficiencies of the prior art:

[0005] In the case of a physical puncture of an electric vehicle battery pack, the occurrence of short circuit and thermal runaway is almost instantaneous. According to research and accident analysis, the battery can quickly heat up to the critical point within seconds to minutes after a short circuit, triggering thermal runaway. Once thermal runaway occurs, the chemical reactions inside the battery will get out of control, resulting in a continuous increase in temperature and pressure, thus causing a fire. More urgently, the time window from the initial signs of thermal runaway to the obvious outbreak of flames is extremely narrow, perhaps only 2 to 3 minutes. This requires the driver and passengers to take immediate action when the first abnormal signs are detected, which greatly increases the urgency of escape and the difficulty of rescue operations. Summary of the Invention

[0006] The purpose of the present invention is to provide a fireproof housing structure for a battery pack to solve the problems raised in the above background art.

[0007] To achieve the above purpose, the present invention provides the following technical solution: A fireproof housing structure for a battery pack, including a bottom cover. The upper end surface of the bottom cover is provided with a plurality of battery module areas. The inside of the battery module areas is provided with a plurality of batteries. A fireproof structure is arranged on the side of the batteries. A cooling mechanism is arranged between the batteries. Isolation mechanisms are arranged on the outside of the battery module areas;

[0008] The fireproof structure includes:

[0009] An intumescent fireproof coating and a cooling part, the intumescent fireproof coating and the cooling part are alternately and spaced along the length direction on the side surface of the battery, and the intumescent fireproof coating and the cooling part between adjacent batteries are arranged in a staggered manner.

[0010] Preferably, the cooling mechanism includes:

[0011] A cooling box, the cooling box is fixedly connected to the bottom cover, and an L-shaped cavity and a motor cavity are arranged inside the cooling box;

[0012] A driving motor, the driving motor is arranged inside the motor cavity, a first rotating shaft is arranged at the output end of the driving motor, the first rotating shaft passes through the short side part of the L-shaped cavity and is rotatably connected to the inner side wall of the cooling box, and an impeller is arranged on the first rotating shaft;

[0013] A volute, the volute is fixedly arranged at the short side part of the L-shaped cavity and is located outside the impeller, a cooling pipe is arranged at the outlet end of the volute, the cooling pipe is provided with a temperature reduction section, the temperature reduction section is arranged between the batteries, a heat conduction plate is arranged on the side surface of the temperature reduction section, the heat conduction plate is attached to the cooling part, and the other end of the cooling pipe is arranged at the top of the long side part of the L-shaped cavity.

[0014] Preferably, a drainage mechanism is arranged inside the cooling box, and the drainage mechanism includes:

[0015] A main gear, the main gear is arranged at the output end of the driving motor;

[0016] A second rotating shaft, the second rotating shaft is arranged at the corner of the L-shaped cavity, a pushing plate is arranged on the side surface of the second rotating shaft, a sub-gear is arranged at the end of the second rotating shaft, and the sub-gear and the main gear are connected by a belt.

[0017] Preferably, the isolation mechanism includes:

[0018] Isolation blocks, the isolation blocks are arranged on both sides of the battery module area, a concave part is arranged on the upper end surface of the isolation blocks, and a plurality of limiting grooves are arranged on the side surface of the concave part;

[0019] Insulating heat conduction plates, the insulating heat conduction plates are arranged on the upper end of the battery module area, a plurality of limiting blocks are arranged on both sides of the insulating heat conduction plates, and the limiting blocks are slidably arranged in the limiting grooves;

[0020] Magnetic attraction blocks, the magnetic attraction blocks are respectively arranged in the concave part and on the lower end surface of the insulating heat conduction plate;

[0021] Low melting point alloy columns, the lower end surfaces of the low melting point alloy columns are fixed in the concave part, the upper end surfaces of the low melting point alloy columns are fixedly connected to the insulating heat conduction plates, and the low melting point alloy columns are used to prevent the insulating heat conduction plates from contacting the isolation blocks.

[0022] Preferably, a heat insulation layer is provided inside the isolation block.

[0023] Preferably, the length of the insulating and heat-conducting plate is less than the length of the battery.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1. For the fireproof housing structure of the battery pack, through the alternately spaced expansion fireproof coatings and cooling parts on the side of the battery, the protection of the battery side is achieved. This design can not only respond quickly when the battery is physically punctured, effectively isolate the flame and heat through the carbonized layer of the expansion fireproof coating, delay the spread of the fire, but also directly create a physical barrier near the fire source to block the fire propagation path, enabling the personnel in the vehicle to have more time to evacuate safely, and also winning a valuable time window for rescue such as fire fighting, reducing property losses. At the same time, it also provides sufficient conditions for the cooling of the cooling mechanism.

[0026] 2. For the fireproof housing structure of the battery pack, through the impeller system driven by the drive motor, combined with the design of the L-shaped chamber and the cooling pipe, the circulating flow of the cooling medium is realized, effectively absorbing and taking away the heat conducted by the battery to the heat-conducting plate. Through the temperature neutralization effect of the heat-conducting plate, the temperature difference between the upper and lower parts of the battery is reduced, ensuring the temperature balance on the surface of the battery. On the other hand, the setting of the drainage mechanism can effectively guide the cooling medium in the long side part of the L-shaped chamber into the short side part, reducing the temperature difference between the long side and the short side, and improving the cooling effect.

[0027] 3. For the fireproof housing structure of the battery pack, through the cooperation of the low-melting-point alloy column and the insulating and heat-conducting plate, when the battery continues to burn, the low-melting-point alloy column is melted, and the insulating and heat-conducting plate automatically drops, thereby reducing the influence of the flame and high temperature on other battery module areas. This design improves the fireproof safety of the battery pack, reduces the possibility of fire spread, and further provides more escape time for the occupants in the vehicle, effectively enhancing the overall safety protection of the vehicle in an emergency. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic top view of the present invention;

[0029] Figure 2 is a schematic bottom view of the present invention;

[0030] Figure 3 is a schematic internal view of the present invention;

[0031] Figure 4 is an enlarged view of part A of the present invention;

[0032] Figure 5Schematic diagram of the structure of a single battery module area of the present invention;

[0033] Figure 6 Enlarged view of part B of the present invention;

[0034] Figure 7 Schematic diagram of the internal structure of the side of the present invention;

[0035] Figure 8 Schematic diagram of the internal structure of the L-shaped cavity of the present invention;

[0036] Figure 9 Schematic diagram of the structure when the single battery module area of the present invention is cooperatively connected with the isolation mechanism;

[0037] Figure 10 Enlarged view of part C of the present invention.

[0038] In the figure: 1, bottom cover; 2, battery module area; 3, battery; 4, fireproof structure; 401, expanded fireproof coating; 402, cooling part; 5, cooling mechanism; 501, cooling box; 502, L-shaped cavity; 503, motor cavity; 504, driving motor; 505, first rotating shaft; 506, impeller; 507, volute; 508, cooling pipe; 5081, temperature reduction section; 509, heat conduction plate; 6, isolation mechanism; 601, isolation block; 602, recessed part; 603, limiting groove; 604, insulating heat conduction plate; 605, limiting block; 606, magnetic attraction block; 607, low melting point alloy column; 7, drainage mechanism; 701, main gear; 702, second rotating shaft; 703, pushing plate; 704, sub-gear; 8, heat insulation layer. Detailed implementation manners

[0039] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0040] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. are based on the orientation or positional relationships shown in the accompanying 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 thus should not be construed as a limitation to the present invention.

[0041] In the description of this patent, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "setting" should be understood in a broad sense. For example, it can be fixedly connected and set, or detachably connected and set, or integrally connected and set. For those of ordinary skill in the art, the specific meanings of the above terms in this patent can be understood according to specific circumstances.

[0042] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, the meaning of "several" is two or more unless otherwise clearly and specifically defined. Embodiment

[0043] Please refer to Figures 1-10 As shown, a technical solution for a fireproof housing structure of a battery pack provided by the present invention: a fireproof housing structure of a battery pack, including a bottom cover 1, several battery module areas 2 are arranged on the upper end surface of the bottom cover 1, several batteries 3 are installed inside the battery module areas 2, a fireproof structure 4 is arranged on the side of the battery 3, a cooling mechanism 5 is arranged between the batteries 3, and isolation mechanisms 6 are arranged on the outside of the battery module areas 2;

[0044] The fireproof structure 4 includes an expandable fireproof coating 401 and a cooling part 402. The expandable fireproof coating 401 and the cooling part 402 are alternately arranged at intervals along the length direction of the side of the battery 3. The expandable fireproof coating 401 and the cooling part 402 between adjacent batteries 3 are arranged in a staggered manner. When the battery 3 is physically pierced, its internal electrodes (anode and cathode) may come into direct contact, causing an internal short circuit, thus quickly generating a large amount of heat energy, leading to thermal runaway and triggering combustion. If the pierced part is the cooling part 402 on the side of the battery, the combustion spreads to the expandable fireproof coating 401 of the opposite battery 3 and the expandable fireproof coatings 401 on both sides. At this time, the expandable fireproof coating 401 on the corresponding side quickly expands to form a carbonized layer, effectively isolating the flame and heat, delaying and preventing the spread of the fire to the adjacent battery 3. If the pierced part is a part of the expandable fireproof coating 401 on the side of the battery 3, it will directly prevent the further spread of the fire. This design can directly create an obstacle near the fire source, effectively blocking the propagation path of the fire and delaying the spread speed of the fire, thereby providing more time for the personnel in the vehicle to evacuate safely and providing a time window for fire fighting and other rescue services to arrive at the scene.

[0045] The cooling mechanism 5 includes a cooling box 501, a driving motor 504, and a volute 507. The cooling box 501 is fixedly connected to the bottom cover 1. The interior of the cooling box 501 is provided with an L-shaped chamber 502 and a motor chamber 503. The driving motor 504 is fixedly installed inside the motor chamber 503. The output end of the driving motor 504 is connected to a first rotating shaft 505. The first rotating shaft 505 passes through the short side of the L-shaped chamber 502 and is rotatably connected to the inner wall of the cooling box 501. An impeller 506 is installed on 505, a volute 507 is fixedly installed on the short side of the L-shaped chamber 502 and is located outside the impeller 506, the outlet end of the volute 507 is connected to a cooling pipe 508, and the cooling pipe 508 is designed with a cooling section 5081, the cooling section 5081 is located between the batteries 3, and a heat conduction plate 509 is connected to the side of the cooling section 5081, and the heat conduction plate 509 is attached to the cooling part 402. The other end of the cooling pipe 508 is located on the long side of the L-shaped chamber 502. At the top of the portion, during the cooling process, the driving motor 504 provides power to drive the first rotating shaft 505 with the impeller 506 to rotate counterclockwise. At this time, the cooling medium is introduced into the volute 507, and enters the cooling pipe 508 after circling inside. As the impeller 506 continues to rotate, the cooling medium will be continuously input into the cooling pipe 508, so that the cooling medium is finally discharged at the top of the long side portion of the L-shaped chamber 502 and can be circulated. When the cooling medium passes through the cooling section 5081, it will take away part of the heat conducted by the battery 3 to the heat conduction plate 509 to achieve cooling. On the other hand, the heat conduction plate 509 can also play a certain role in temperature neutralization, reducing the temperature difference between the upper and lower parts of the battery 3. When the cooling medium leaves the cooling section 5081 and enters the L-shaped chamber 502 again, it will be temperature neutralized with the cooling medium in the chamber to achieve cooling, and will be discharged at the top of the long side portion of the L-shaped chamber 502 to merge with the external cooling medium.

[0046] A drainage mechanism 7 is provided inside the cooling box 501, and the drainage mechanism 7 includes a main gear 701 and a second rotating shaft 702. The main gear 701 is installed at the output end of the driving motor 504, and the second rotating shaft 702 is installed at the corner of the L-shaped chamber 502. A pushing plate 703 is installed on the side of the second rotating shaft 702, and a sub-gear 704 is installed at the end of the second rotating shaft 702. The sub-gear 704 and the main gear 701 are connected by a belt. In order to prevent the temperature difference between the long side and the short side of the L-shaped chamber 502 from being too large and to achieve more effective cooling, a drainage mechanism 7 is set up. During drainage, the driving motor 504 provides power, and the second rotating shaft 702 with the pushing plate 703 is rotated through the structure of the belt and gear. At this time, the first rotating shaft 505 and the second rotating shaft 702 have the same rotation direction, which can effectively guide the cooling medium of the long side of the L-shaped chamber 502 into the short side, reduce the temperature difference, and improve the cooling efficiency.

[0047] The isolation mechanism 6 includes an isolation block 601, an insulating heat-conducting plate 604, a magnetic attraction block 606, and a low-melting-point alloy column 607. The isolation block 601 is installed on both sides of the battery module area 2. A recess 602 is provided on the upper end surface of the isolation block 601, and a number of limiting grooves 603 are provided on the side surface of the recess 602. The insulating heat-conducting plate 604 is located above the battery module area 2. A number of limiting blocks 605 are connected to both sides of the insulating heat-conducting plate 604, and the limiting blocks 605 are slidably arranged in the limiting grooves 603. The magnetic attraction blocks 606 are respectively installed in the recess 602 and on the lower end surface of the insulating heat-conducting plate 604. The lower end surface of the low-melting-point alloy column 607 is fixed in the recess 602, and the upper end surface of the low-melting-point alloy column 607 is fixedly connected to the insulating heat-conducting plate 604. The low-melting-point alloy column 607 is used to prevent the insulating heat-conducting plate 604 from contacting the isolation block 601. In the specific implementation process, the insulating heat-conducting plate 604 can be alumina ceramic, and the low-melting-point alloy column 607 can be bismuth-tin alloy. During the continuous combustion process of the battery 3, the temperature of the insulating heat-conducting plate 604 located above it will continue to rise and continuously transfer heat to the low-melting-point alloy column 607. When the melting point of the low-melting-point alloy column 607 is reached, it will melt and flow into the interior of the recess 602. At this time, the insulating heat-conducting plate 604 will cover the upper end of the battery module area 2, reducing the impact on the remaining battery module areas 2.

[0048] An insulating layer 8 is provided inside the isolation block 601. In the specific implementation process, the insulating layer 8 can be an asbestos layer. This design can effectively control the temperature inside a single battery module area 2, thereby enhancing the overall thermal management efficiency. By providing the asbestos insulating layer 8, not only can the heat transfer between the batteries 3 be effectively blocked, but also when the battery 3 undergoes thermal runaway or combustion, the thermal impact of high temperature on the adjacent battery module area 2 can be prevented, thereby reducing the risk of fire spread.

[0049] The length of the insulating heat-conducting plate 604 is less than the length of the battery 3. This design can ensure that when the insulating heat-conducting plate 604 is closed, there are still gaps at both ends of the battery 3, which helps the internal heat dissipation and also avoids the safety risks that may be caused by the complete sealing of the battery module area 2. These gaps allow air to flow, thereby helping to regulate and stabilize the temperature inside the battery module area 2 and reducing the overheating problem caused by heat accumulation.

[0050] The working principle of the present invention is as follows:

[0051] A fireproof housing structure of a battery pack provided in this embodiment adopts multiple protection mechanisms to ensure the safety of the battery pack. First of all, the design of the fireproof structure 4 is one of the cores. It effectively copes with the fire risk that may be caused by the physical puncture or thermal runaway of the battery 3 through the alternating and spaced arrangement of the expansion fireproof coating 401 and the cooling part 402. When the battery 3 is punctured, causing an internal short circuit and generating a large amount of heat energy, if the punctured part is the cooling part 402, the expansion fireproof coatings 401 on the opposite side and both sides will quickly expand to form a carbonized layer. This carbonized layer is like a firewall, effectively isolating the flame and heat, and preventing the fire from spreading to the adjacent battery 3. If the punctured part is directly the expansion fireproof coating 401, it directly blocks the further diffusion path of the fire.

[0052] Secondly, the cooling mechanism 5 drives the impeller 506 to rotate through the drive motor 504, forming a circulating flow of the cooling medium. When the cooling medium flows through the temperature reduction section 5081, it can absorb and take away the heat conducted by the battery 3 through the heat conduction plate 509, achieving rapid cooling. The introduction of the heat conduction plate 509 not only improves the heat conduction efficiency but also helps to balance the temperature difference between the upper and lower parts of the battery 3, further ensuring the stable operation of the battery pack. In addition, the drainage mechanism 7 makes the push plate 703 rotate synchronously with the impeller 506 through the belt and gear transmission system, effectively guiding the uniform distribution of the cooling medium in the L-shaped cavity 502, reducing the temperature difference between the long side and the short side parts, and improving the overall cooling efficiency.

[0053] Finally, the isolation mechanism 6 plays a key role when the battery 3 undergoes severe combustion. As the combustion continues, the temperature of the insulating heat conduction plate 604 continuously rises, and the heat is transferred to the lower part through the low-melting-point alloy column 607. Once the melting point of the low-melting-point alloy column 607 is reached, the alloy column melts and flows into the recess 602. At this time, the insulating heat conduction plate 604 drops due to the loss of support and tightly covers the upper end of the battery module area 2. This design quickly isolates the combustion area and effectively prevents the fire and high temperature from affecting other battery modules, further improving the overall safety of the battery pack.

[0054] In summary, through the synergistic effect of the fireproof structure 4, the cooling mechanism 5 and the isolation mechanism 6, the present invention realizes multiple protections for the battery pack, significantly improves the safety performance of the battery pack in extreme cases, and provides a more reliable technical guarantee for fields such as electric vehicles and energy storage systems.

[0055] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and the above embodiments and the descriptions in the specification are only preferred examples of the present invention and are not used to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A fireproof housing structure of a battery pack, comprising a bottom cover (1), characterized in that: The upper end surface of the bottom cover (1) is provided with a plurality of battery module areas (2), the inner side of the battery module area (2) is provided with a plurality of batteries (3), the side of the battery (3) is provided with a fireproof structure (4), a cooling mechanism (5) is provided between the batteries (3), and the outer side of the battery module area (2) is provided with an isolation mechanism (6); The fireproof structure (4) comprises: An intumescent fireproof coating (401) and a cooling portion (402), wherein the intumescent fireproof coating (401) and the cooling portion (402) are alternately arranged at intervals on the side of the battery (3) along its length direction, and the intumescent fireproof coating (401) and the cooling portion (402) between adjacent batteries (3) are arranged in a staggered manner.

2. A fireproof housing structure for a battery pack according to claim 1, characterized in that: The cooling mechanism (5) comprises: A cooling box (501), the cooling box (501) being fixedly connected to the bottom cover (1), and the interior of the cooling box (501) being provided with an L-shaped chamber (502) and a motor chamber (503); A drive motor (504), the drive motor (504) being arranged inside the motor chamber (503), a first rotating shaft (505) being arranged at an output end of the drive motor (504), the first rotating shaft (505) passing through a short side portion of the L-shaped chamber (502) and being rotatably connected to an inner wall of the cooling box (501), and an impeller (506) being arranged on the first rotating shaft (505); A volute (507), the volute (507) being fixedly arranged on the short side of the L-shaped chamber (502) and being located outside the impeller (506); a cooling pipe (508) being arranged at the outlet end of the volute (507); the cooling pipe (508) being provided with a cooling section (5081); the cooling section (5081) being arranged between the batteries (3); a heat conduction plate (509) being arranged on the side of the cooling section (5081); the heat conduction plate (509) being arranged in contact with the cooling portion (402); and the other end of the cooling pipe (508) being arranged at the top of the long side of the L-shaped chamber (502).

3. A fireproof housing structure for a battery pack according to claim 2, characterized in that: A drainage mechanism (7) is provided inside the cooling box (501), and the drainage mechanism (7) comprises: A main gear (701), wherein the main gear (701) is arranged at the output end of the driving motor (504); A second rotating shaft (702), wherein the second rotating shaft (702) is arranged at a corner of the L-shaped chamber (502), a pushing plate (703) is arranged on a side of the second rotating shaft (702), and a secondary gear (704) is arranged at an end of the second rotating shaft (702), wherein the secondary gear (704) and the main gear (701) are connected via a belt.

4. The fireproof housing structure of a battery pack according to claim 1, characterized in that: The isolation mechanism (6) comprises: An isolation block (601), the isolation block (601) being arranged on both sides of the battery module area (2), the upper end surface of the isolation block (601) being provided with a recessed portion (602), and the side surfaces of the recessed portion (602) being provided with a plurality of limiting grooves (603); An insulating heat conducting plate (604), the insulating heat conducting plate (604) being arranged at the upper end of the battery module area (2), a plurality of limit blocks (605) being arranged on both sides of the insulating heat conducting plate (604), the limit blocks (605) being slidably arranged in the limit grooves (603); A magnetic attraction block (606), wherein the magnetic attraction block (606) is respectively arranged in the recessed portion (602) and on the lower end surface of the insulating heat conducting plate (604); A low melting point alloy column (607), wherein the lower end surface of the low melting point alloy column (607) is fixed in the recessed portion (602), the upper end surface of the low melting point alloy column (607) is fixedly connected to the insulating heat conductive plate (604), and the low melting point alloy column (607) is used to prevent the insulating heat conductive plate (604) from contacting the isolation block (601).

5. A fireproof housing structure for a battery pack according to claim 4, characterized in that: A heat insulating interlayer (8) is provided inside the isolation block (601).

6. A fireproof housing structure for a battery pack according to claim 4, characterized in that: The length of the insulating heat-conducting plate (604) is smaller than the length of the battery (3).

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