A power battery module based on PCM heat absorption plate heat dissipation

Abstract

This invention discloses a power battery module based on a PCM heat absorber plate, comprising a battery pack consisting of several cylindrical batteries arranged in an array; a PCM heat absorber plate, the interior of which is filled with a thermally conductive porous structure and paraffin phase change material, which absorbs heat through melting of the phase change material to reduce battery temperature; the PCM heat absorber plate is provided with several sleeve structures, the sleeves being connected front and rear along the air-cooling flow direction via sleeve connecting plates, and the cylindrical batteries being mounted on the PCM heat absorber plate through the sleeve structures; heating strips, located at the bottom of the PCM heat absorber plate and perforated, fitting around the sleeves, used to heat the battery pack at low temperatures; and a cooling fan, located at the head or tail of the PCM heat absorber plate, used for air-cooling heat dissipation of the battery pack and the PCM heat absorber plate. This invention, using a PCM heat absorber plate, can enhance the thermal conductivity and heat absorption capacity between batteries, thereby reducing local hot spots and temperature differences between batteries, achieving efficient thermal management.

Description

Technical Field

[0001] This invention relates to the field of power battery heat dissipation, and in particular to a power battery module based on PCM heat absorption plate heat dissipation. Background Technology

[0002] Power battery technology is a key technology restricting the development of electric vehicles. An efficient battery module cooling system is crucial to ensuring the performance of electric vehicles. The chemical properties of power batteries are significantly affected by temperature. During operation, the batteries themselves release heat, causing the battery temperature to rise. Furthermore, the battery modules of electric vehicles consist of hundreds of cells connected in series and parallel with close spacing, leading to heat accumulation, resulting in localized overheating and uneven temperature distribution, affecting battery performance and consequently, the overall vehicle performance. The heat dissipation and temperature uniformity of the battery module have a significant impact on battery performance, cycle life, and safety.

[0003] Currently, the main heat dissipation technologies for cylindrical and prismatic power battery modules on the market are air cooling and liquid cooling. Both air cooling and liquid cooling utilize convection heat transfer between the cooling medium and the battery's heat dissipation surface to remove heat; the main difference lies in the cooling medium. Air cooling has advantages such as low cost, simple system structure, and easy maintenance. However, air has low specific heat capacity and thermal conductivity, and as battery energy density increases, air cooling alone cannot meet the requirements of maintaining the battery below 50°C and keeping the battery temperature difference within 5°C. Liquid cooling has advantages such as fast cooling speed and high cooling efficiency, but it requires higher system sealing and coolant performance, has a complex structure, is difficult to install and maintain, and has high manufacturing and operating costs.

[0004] For example, patent document No. 202010772517.8 discloses a thermal management device for electric vehicle batteries that integrates air cooling and liquid cooling, including a housing and multiple rows of battery packs disposed within the housing; each row of battery packs consists of multiple individual cells; each individual cell is embedded in a composite phase change material body; the top and bottom of the composite phase change material body are respectively attached to a liquid cooling plate; the liquid cooling plate is connected to a water pump; the water pump is connected to a water tank; a heat dissipation plate is disposed between every two adjacent rows of battery packs; one end of the heat dissipation plate is embedded in the composite phase change material body, and the other end is exposed to the air inside the housing; a cooling fan is disposed on the housing for heat exchange of the heat dissipation plate.

[0005] The aforementioned patented solution uses a heat sink between every two rows of adjacent battery packs to remove heat from individual batteries, achieving a cooling effect. A cooling fan then expels the hot air outside the enclosure. Simultaneously, a circulating water path formed between the water tank and the liquid cooling plate removes heat from the top and bottom of the individual batteries, as well as the composite phase change material, achieving a cooling effect. This heat dissipation cycle can control the maximum temperature rise of the battery within a reasonable operating range.

[0006] However, with the increase in energy density and large-scale integration of power batteries, the heat dissipation requirements for electric vehicles are becoming increasingly stringent. This necessitates the development of more efficient battery cooling technologies to suppress the thermal runaway of one battery from spreading to surrounding batteries and preventing large-scale thermal runaway. Simultaneously, in low-temperature environments, the internal resistance of power batteries increases, preventing the full release of their output energy and resulting in a shorter driving range for electric vehicles, thus impacting the driving experience.

[0007] Therefore, it is necessary to improve such a structure to overcome the aforementioned defects. Summary of the Invention

[0008] The purpose of this invention is to provide a power battery module based on a PCM heat absorber plate for heat dissipation. The use of a multi-perforated PCM heat absorber plate significantly enhances the thermal conductivity between batteries, thereby reducing the temperature difference between local hot spots and the battery itself, achieving efficient thermal management and even suppressing the spread of battery thermal runaway. Excess heat is carried away by a fan and tail fins, keeping the overall battery temperature within a safe range. Furthermore, a unique sleeve structure is machined on the bottom and top plates of the heat absorber plate to enhance heat transfer. The top and bottom sleeves are connected along the flow direction by a top and bottom sleeve connecting plate. This not only fixes the battery in place, preventing displacement during operation, but also increases the contact area between the battery and the heat absorber plate, increasing heat flow and further improving the uniform temperature performance of the battery pack.

[0009] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0010] A power battery module based on PCM heat absorber plate heat dissipation, including

[0011] A battery pack, wherein the battery pack consists of several cylindrical batteries arranged in an array;

[0012] The PCM heat absorber plate is filled with a PCM composite thermally conductive porous structure, and has several hollow sleeves on it. The hollow sleeves contain cylindrical batteries. Specifically, the hollow sleeves are arranged in a straight line or staggered arrangement on the PCM heat absorber plate, and multiple cylindrical batteries are installed on the PCM heat absorber plate at intervals through the hollow sleeves. The tiny gaps between the cylindrical batteries and the hollow sleeves are filled with thermally conductive silicone to reduce contact thermal resistance and improve thermal conductivity.

[0013] The heating strip, which is strip-shaped, is located between the bottom or top sleeve of the PCM heat absorption plate and does not occupy the battery space. It is used to heat the battery pack at low temperatures.

[0014] A cooling fan is provided, located on the side of the PCM heat absorber plate, for air cooling of the battery pack and the PCM heat absorber plate.

[0015] Furthermore, the heat-absorbing top plate and the heat-absorbing bottom plate form a hollow cavity, in which PCM phase change material is filled. Several top plate sleeves are provided on the heat-absorbing top plate, several bottom plate sleeves are provided on the heat-absorbing bottom plate, and several intermediate sleeves are provided on the heat-conducting porous structure. The top plate sleeves, bottom plate sleeves and intermediate sleeves are arranged correspondingly and form a sleeve structure for installing cylindrical batteries.

[0016] The top plate sleeves on the heat-absorbing top plate are connected to each other along the air-cooling flow direction via an upper connecting plate, and the bottom plate sleeves on the heat-absorbing bottom plate are connected to each other along the air-cooling flow direction via a lower connecting plate; the upper connecting plate and the lower connecting plate are used to enhance the heat conduction between the cylindrical batteries.

[0017] The heat-absorbing top plate is equipped with a liquid injection pipe, which is used to inject PCM phase change material into the hollow cavity and for maintenance and heat dissipation. The heat-absorbing top plate is equipped with an exhaust hole, which is used to vent air from inside the heat-absorbing plate during the liquid injection process. The heat-absorbing bottom plate is equipped with an exhaust blind hole corresponding to the exhaust hole on the heat-absorbing top plate. The exhaust blind hole is used to seal and reinforce the top plate sleeve, the thermally conductive porous structure, and the heat-absorbing bottom plate after the liquid injection is completed, by connecting with a nut.

[0018] Furthermore, the top plate sleeve and the bottom plate sleeve are arranged in a straight line on the heat-absorbing top plate and the heat-absorbing bottom plate; or

[0019] The top plate sleeve and the bottom plate sleeve are arranged alternately on the heat-absorbing top plate and the heat-absorbing bottom plate.

[0020] Furthermore, the inner surfaces of the top plate sleeve and the bottom plate sleeve are provided with thermally conductive silicone.

[0021] Furthermore, the upstream and downstream sleeves are connected by a sleeve connecting plate, a tail sleeve, or connected extended fins, or non-connecting fins are arranged in the gap between the tail sleeves to further increase the heat dissipation area and improve the battery's heat dissipation capacity. The non-connecting fins achieve a lower temperature difference than the extended fins of the connecting sleeve.

[0022] Furthermore, the sleeves near the downstream end and the tail end are lengthened along the battery direction, exceeding the length of the upstream battery sleeve. This further increases the contact area of ​​the downstream battery and the heat conduction capacity from both ends of the downstream battery to the central heat absorption plate, thereby reducing the temperature level of the downstream battery and improving the uniform temperature performance of the battery module.

[0023] Furthermore, the thermally conductive porous structure includes several hollow cavities composed of a heat-absorbing top plate and a heat-absorbing bottom plate. The interior of the hollow cavities is arranged with thermally conductive porous structures and filled with liquid PCM phase change material.

[0024] Furthermore, the PCM is a phase change material such as organic paraffin; the heat-absorbing top plate and the heat-absorbing bottom plate are made of aluminum alloy.

[0025] Furthermore, the outer material of the heating strip is polyimide, and several openings slightly larger than the base plate sleeve are provided on the heating strip.

[0026] Furthermore, the heat-absorbing top plate and the heat-absorbing bottom plate are connected by a vacuum brazing process.

[0027] Furthermore, the heat-absorbing base plate sleeve has an enlarged surface welding extension area, which is achieved through bottom cutting process and large-area welding connection with the heat-absorbing base plate through vacuum brazing process, thereby improving processing convenience and sealing performance.

[0028] Furthermore, heat dissipation fins are provided at the top and bottom of the heat absorption plate to improve its heat dissipation performance.

[0029] Furthermore, the injection hole can be placed at the edge, the middle, or the four corners, and the heat absorption plate exhaust hole should be placed at the four corners where flow dead zones are likely to form, away from the injection hole, so as to facilitate the removal of air bubbles and avoid embedding air bubbles that would affect the heat absorption performance.

[0030] Furthermore, the exhaust vent of the heat-absorbing plate is finally sealed by a nut, and due to the function of the blind vent of the heat-absorbing base plate, the nut also serves to reinforce the connection between the top plate and the base plate.

[0031] Furthermore, a connecting plate is added between the heat-absorbing plate sleeves to enhance the heat conduction between the batteries, making the temperature of the battery module more uniform.

[0032] The outer surface of the PCM heat absorber plate is anodized to form an insulating, corrosion-resistant, and heat-resistant layer.

[0033] In summary, the present invention has the following beneficial effects:

[0034] Firstly, a PCM heat absorber plate is used, incorporating a high-porosity porous thermally conductive structure made of PCM phase change material. Batteries are installed at intervals with openings in the middle. Compared to a simple metal heat diffuser plate, this design reduces weight while enhancing heat absorption capacity. Alternatively, more PCM can be added to further improve heat absorption capacity within the same weight and module dimensions, thereby reducing the temperature difference between localized hot spots and the battery itself, achieving efficient thermal management. Furthermore, sleeve structures are machined on both the bottom and top plates of the heat absorber plate to enhance heat transfer. The top and bottom sleeves are connected along the flow direction via a sleeve connecting plate, which not only fixes the battery and stabilizes the structure but also increases the contact area between the battery and the heat absorber plate, enhancing the heat transfer rate from the battery to the heat absorber plate. Simultaneously, the temperature difference within the battery pack is reduced, and the temperature uniformity is further improved.

[0035] Secondly, the ducting fan at one end of the battery pack can be turned on according to the operating conditions to force convection heat exchange on the PCM heat absorber plate. At the same time, the height of the downstream heat absorber plate sleeve is increased. The sleeves are connected to each other and to the tail fins. By utilizing the synergistic effect of the high-efficiency heat absorption of the PCM heat absorber plate and the heat dissipation of the fins, the maximum temperature and temperature difference of the battery pack are further reduced. The effect is significant, and the heat dissipation structure is simple, compact, safe and reliable, with good application prospects.

[0036] Thirdly, the base plate sleeve and top plate are welded together using a vacuum brazing process, resulting in a strong weld with good sealing performance, preventing leakage even when the PCM melts. Thermally conductive silicone is added between the battery and the sleeve to reduce the contact thermal resistance of the mating surfaces and absorb the expansion stress, further improving thermal conductivity.

[0037] Fourth, a heating strip is installed at the bottom of the PCM heat absorber plate. During heating, the temperature of the heating strip is reduced by the uniform temperature effect of the PCM heat absorber plate, thereby improving heating efficiency, quickly heating the battery, and ensuring the normal use of the battery module in low-temperature conditions. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the battery module assembly structure of the present invention (in a straight row).

[0039] Figure 2 This is an exploded view (in a straight line) of the PCM heat absorber plate structure in this invention.

[0040] Figure 3a This is a top view (in a straight row) of the PCM heat absorber plate in this invention.

[0041] Figure 3b This is a cross-sectional view (in a straight row) of the PCM heat absorber plate in this invention.

[0042] Figure 4 This is a side sectional view (in a straight row) of the PCM heat absorber plate AA in this invention.

[0043] Figure 5 This is a flow diagram of the hollow PCM injection system in this invention (straight rows, ignoring the sleeve connecting plate for ease of illustration).

[0044] Figure 6 This is a schematic diagram of the heating strips on the heat-absorbing plate in this invention (arranged in a straight line).

[0045] Figure 7 This is a top view (interlaced) of the battery module assembly structure in this invention.

[0046] Figure 8 This is a schematic diagram of the battery module assembly structure of the present invention (interlaced).

[0047] Figure 9This is a schematic diagram of the cooling operation of the single-sided finned fan of the present invention (in a straight row).

[0048] Figure 10 This is a schematic diagram of the cooling operation of the double-finned fan of the present invention (in a straight row, with the downstream sleeve heightened).

[0049] Figure 11 The present invention maintains a PCM heat absorption plate of the same volume as the metal plate and fins in the gap between the top plate tail sleeve, with an air inlet temperature of 32°C. The battery temperature cloud map is obtained at the end of the battery discharge at 3C (3 times rate).

[0050] Figure 12 The present invention provides an air inlet temperature of 32°C, maintains the same weight as the metal plate, thickens the PCM heat absorption plate (increasing the PCM thickness from 4mm to 7mm), and adds fins to the gap between the top plate and the sleeve. This is a battery temperature cloud map at the end of the battery's 3C (3x rate) discharge.

[0051] The diagram shows the following markings: 1. Battery pack; 2. PCM heat absorber plate (in line); 21. Heat absorber top plate (in line); 22. Thermally conductive porous structure (in line); 23. Heat absorber bottom plate (in line); 211. Top plate sleeve; 212. Fin; 213. Nut; 214. Sealing gasket; 215. Vent; 216. Injection pipe; 217. Upper connecting plate; 231. Bottom plate sleeve; 232. Welding extension surface; 233. Hollow cavity; 234. Vent blind hole; 235. Lower connecting plate; 3. PCM heat absorber plate (staggered); 4. Heating strip; 41. Opening; 5. Drainage fan; Detailed Implementation

[0052] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to the figures and specific embodiments.

[0053] like Figures 1 to 12 As shown, the present invention proposes a power battery module based on PCM heat absorption plate heat dissipation, including...

[0054] Battery pack 1, wherein the battery pack 1 is a plurality of cylindrical batteries arranged in an array;

[0055] PCM heat absorber plate 2 has a built-in thermally conductive porous structure, such as high-voidity aluminum foam, such as aluminum foam with a void ratio of 96%, and is filled with PCM material. The PCM heat absorber plate 2 is provided with several sleeve structures, and the cylindrical battery is set on the PCM heat absorber plate 2 through the sleeve structures.

[0056] Heating strip 4 is disposed at the bottom of PCM heat absorption plate 2, and has openings to accommodate a sleeve for heating battery pack 1 at low temperatures;

[0057] A cooling fan 5 is provided on the side of the PCM heat absorber plate 2, which is used to provide air cooling for the battery pack 1 and the PCM heat absorber plate 2.

[0058] The PCM heat absorption plate (2) includes a heat absorption top plate (21), a heat absorption bottom plate (23), and a heat-conducting porous structure (22) disposed between the heat absorption top plate (21) and the heat absorption bottom plate (23);

[0059] The heat-absorbing top plate 21 and the heat-absorbing bottom plate 23 form a hollow cavity 233, which is filled with PCM phase change material. A plurality of top plate sleeves 211 are provided on the heat-absorbing top plate 21, and a plurality of bottom plate sleeves 231 are provided on the heat-absorbing bottom plate 23. A plurality of intermediate sleeves are provided on the heat-conducting porous structure 22. The top plate sleeves 211, bottom plate sleeves 231 and intermediate sleeves are arranged correspondingly and form a sleeve structure for installing cylindrical batteries.

[0060] The top plate sleeves 211 on the heat-absorbing top plate 21 are connected to each other along the air-cooling flow direction via the upper connecting plate 217, and the bottom plate sleeves 231 on the heat-absorbing bottom plate 23 are connected to each other along the air-cooling flow direction via the lower connecting plate 235; the upper connecting plate 217 and the lower connecting plate 235 are used to enhance the heat conduction between the cylindrical batteries.

[0061] The heat-absorbing top plate 21 is provided with a liquid injection pipe 215, which is used to inject PCM phase change material into the hollow cavity 233 and for maintenance and heat dissipation. The heat-absorbing top plate 21 is provided with an exhaust hole 214, which is used to vent air from inside the heat-absorbing plate 2 during the liquid injection process. The heat-absorbing bottom plate 23 is provided with an exhaust blind hole 234 corresponding to the exhaust hole 214 on the heat-absorbing top plate 21. The exhaust blind hole 234 is used to seal and reinforce the top plate sleeve 211, the heat-conducting porous structure 22 and the heat-absorbing bottom plate 23 after the liquid injection is completed by connecting with the nut 213. The exhaust blind hole is slightly lower than the top plate and is used to observe and determine whether the liquid injection is complete.

[0062] The battery pack 1 is composed of several cylindrical batteries arranged in different ways, with spacing between adjacent batteries. They are connected by a PCM heat absorption plate 2, which effectively improves the safety of the battery pack 1 and prevents the occurrence of battery thermal runaway.

[0063] The preferred arrangement in this example is as follows: Figure 1 , Figure 8 As shown, adjacent batteries are arranged in a straight line or staggered arrangement at a certain interval and used in conjunction with PCM heat absorption plates (straight line arrangement) and PCM heat absorption plates (staggered arrangement), respectively.

[0064] The cylindrical batteries of the battery pack 1 are inserted into the top sleeve 211 and bottom sleeve 231 of the PCM heat absorber plate 2, with a tight fit to fix the batteries in the PCM heat absorber plate. The battery surface is in close contact with the sleeve surface and thermally conductive silicone is added to reduce the contact thermal resistance between them and accelerate heat transfer. The heating strip 4 is used to quickly heat the batteries in cold weather. Due to the rapid heat conduction of the PCM heat absorber plate, no local hot spots are generated, avoiding local overheating of the heating strip 4 and rapid failure, thus improving thermal safety. The injection pipe 215 with injection holes is set at the edge of the PCM heat absorber plate 2, arranged vertically upward with the PCM heat absorber plate 2. The injection pipe 215 is used for the injection process of the hollow cavity 233 in the PCM heat absorber plate 2. It can be reprocessed and repaired later and reused for multiple injections. At the same time, it can also be used as a heat dissipation column for heat dissipation.

[0065] like Figure 5 As shown in the figure, the PCM flow is as follows when liquid is injected into the heat absorber plate. The purpose of this setting is to ensure that the PCM is evenly distributed and to avoid the generation of air bubbles that would lead to poor local heat conduction. The injection hole can be placed at the edge, the middle or the four corners, while the vent hole should be placed at the four corners where flow dead zones are likely to form, away from the injection hole, to avoid air bubbles from being embedded.

[0066] Taking PCM heat absorber plates (in-line arrangement) as an example, such as Figure 2 Figure 3 Figure 4 As shown, the PCM heat absorber plate 2 consists of a top plate 21, a thermally conductive porous structure 22, and a bottom plate 23. A top plate sleeve 211 is formed on the top plate, and a bottom plate sleeve 231 is formed on the bottom plate. The bottom plate sleeve is divided into inner and outer parts. The outer sleeve is aligned in size and position with the top plate sleeve, while the inner sleeve, as part of the sleeve structure, not only fixes the battery but also supports the top plate and the hollow cavity 233. The thermally conductive porous structure 22, which can completely or partially fill the hollow cavity, is made of a highly thermally conductive and porous material such as copper or aluminum and is placed inside the heat absorber plate. The top plate 21 and the bottom plate 23 are connected by vacuum brazing, resulting in high welding efficiency, a robust structure, and low cost.

[0067] The PCM of this invention is preferably an organic phase change material such as paraffin wax or fatty acids, with a melting point temperature between 30 and 60°C. The melting point temperature should be higher than the ambient temperature at which the battery is used to maximize the latent heat absorption performance of the PCM. The top and bottom plates are preferably made of aluminum alloys with good processing properties, such as 6061 aluminum. The selected porous thermally conductive structure is high-porosity aluminum foam, such as 96% aluminum foam. The thermal conductivity of the aluminum foam composite PCM is measured to be 1.9 W / mK, which is an order of magnitude higher than the 0.2 W / mK thermal conductivity of the phase change material. Furthermore, the density of the composite material is only 0.87 kg / L, far less than the density of pure aluminum (2.7 kg / L).

[0068] The heating strip of this invention is made of polyimide, and its size is similar to that of the heat absorber plate. The opening 41 is slightly larger than the sleeve size, allowing it to be fitted onto the heat absorber plate sleeve and tightly adhered to the bottom plate of the heat absorber plate. The heating strip is as follows... Figure 6 As shown.

[0069] This invention uses a PCM heat-absorbing plate as the main component, coupled with air cooling to enhance heat dissipation. The specific process for heat dissipation of a cylindrical battery is as follows:

[0070] The heat generated by the cylindrical battery is transferred from inside the battery to the battery casing. On one hand, it is transferred to the PCM heat absorber plate through the contact surface between the battery and the sleeve, utilizing the large contact area between the sleeve and the battery for heat transfer. The tight fit between the sleeve and the cylindrical battery secures the battery, and a thin layer of thermally conductive silicone is added between the sleeve and the cylindrical battery to reduce contact thermal resistance and buffer stress. The anodized aluminum sleeve, together with the thermally conductive silicone and the heat-shrink film on the battery surface, forms an electrically insulating protective layer. The heat generated by the battery, after being enhanced by the heat collection effect of the sleeve, is transferred to the interior of the PCM heat absorber plate through the thermally conductive porous structure. The PCM heat absorber plate heats up, and once it reaches the PCM melting point, it absorbs heat at a constant temperature through latent heat of phase change while maintaining a relatively constant temperature, thus keeping the battery temperature constant.

[0071] On the other hand, such as Figure 9 As shown, the heat from the battery portion that is in direct contact with the air is directly cooled by enhanced airflow through the exhaust fan 5.

[0072] like Figure 10 As shown, double-sided fins are added to both the top and bottom, and enhanced air cooling is achieved directly through the exhaust fan 5, which can further enhance heat transfer.

[0073] The present invention discloses a cylindrical power battery module based on a PCM heat absorber plate. Considering the low-temperature use of the battery, a heating strip is set at the bottom of the PCM heat absorber plate. During heating, the heat is quickly transferred to the battery through the rapid heat transfer effect of the PCM heat absorber plate, ensuring that the battery module heats up quickly at low temperatures. On the other hand, it reduces the temperature of the heating strip, ensuring that the heating strip can work reliably for a long time without the risk of overheating.

[0074] To verify the effectiveness and practicality of this invention, a thermal simulation analysis was performed based on the structure of this invention. With an inlet wind speed of 1 m / s and an inlet temperature of 32°C, the simulation results for a PCM heat absorber plate of the same volume as the metal heat absorber plate at the end of 3C discharge are as follows: Figure 11As shown in Table 1, the highest temperature and temperature difference of the battery module with a simple heat diffuser plate (without a PCM heat absorber) are 47.03℃ and 5.03℃, respectively. However, with the PCM heat absorber, the highest temperature and temperature difference are 45.34℃ and 4.38℃, respectively, representing a decrease of 11.2% in the highest battery module temperature and a decrease of 12.9% in the temperature difference.

[0075] With an inlet wind speed of 1 m / s and an inlet temperature of 32°C, the simulation results of a PCM heat absorber of the same weight as the metal heat absorber at the end of 3C discharge are as follows: Figure 12 As shown in Table 1, the highest temperature and temperature difference for the same weight of PCM heat absorber were 44.64℃ and 3.95℃, respectively. The highest temperature of the battery module decreased by 15.9%, and the temperature difference decreased by 21.5%, while the pressure difference remained at a low level of ~21.9Pa, demonstrating the dual advantages of the present invention in heat dissipation and temperature uniformity. Using double-sided tail fins is superior to using single-sided tail fins, resulting in a 1.8% reduction in maximum temperature and a 5% reduction in temperature difference.

[0076]

[0077] Table 1. Comparison of simulation results of thermal performance of PCM heat absorber under different structural conditions

[0078] To verify the thermal safety performance of the battery module of this invention, a trigger condition for battery thermal runaway was set. Simulation analysis was conducted on heat propagation when a single battery experienced thermal runaway and generated significant heat, with an inlet wind speed of 1 m / s. The simulation results showed that the thermal runaway battery reached temperatures above 600°C, but the closest battery temperature only reached a maximum of 107°C, while other battery temperatures remained below 100°C, significantly lower than the battery's thermal runaway temperature of 120°C. This indicates that the present invention has a good effect on suppressing the propagation of thermal runaway.

[0079] In summary, this invention fully utilizes the enhanced heat collection and temperature equalization capabilities of the PCM heat absorber plate and the enhanced heat dissipation of air cooling. It has a simple and compact structure, significant heat dissipation effect, and greatly improves the reliability and safety of the entire battery module.

[0080] In this document, the terms "upper," "lower," "front," "back," "left," "right," "top," "bottom," "inner," "outer," "vertical," and "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used for the clarity of expressing the technical solution and for the convenience of description, and therefore should not be construed as limiting the present invention.

[0081] In this document, the terms “including,” “comprising,” or any other variations thereof are intended to cover non-exclusive inclusion, which includes not only the elements listed but also other elements not expressly listed.

[0082] 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 to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A power battery module based on PCM heat absorption plate heat dissipation, characterized in that, include: Battery pack (1), wherein the battery pack (1) is a plurality of cylindrical batteries arranged in an array; PCM heat absorption plate (2), the PCM heat absorption plate (2) is provided with several sleeve structures, and the cylindrical battery is set on the PCM heat absorption plate (2) through the sleeve structures; Heating strip (4), which is disposed at the bottom of PCM heat absorption plate (2), is used to heat the battery pack (1) at low temperature; A cooling fan (5) is provided on the side of the PCM heat absorber plate (2) for air cooling of the battery pack (1) and the PCM heat absorber plate (2). The PCM heat absorber plate (2) includes a heat absorber top plate (21), a heat absorber bottom plate (23), and a heat-conducting porous structure (22) disposed between the heat absorber top plate (21) and the heat absorber bottom plate (23). The heat absorber top plate (21) and the heat absorber bottom plate (23) are connected by a vacuum brazing process. The heat-absorbing top plate (21) and the heat-absorbing bottom plate (23) form a hollow cavity (233), and PCM phase change material is filled in the hollow cavity (233). A number of top plate sleeves (211) are provided on the heat-absorbing top plate (21), and a number of bottom plate sleeves (231) are provided on the heat-absorbing bottom plate (23). A number of intermediate sleeves are provided in the heat-conducting porous structure (22). The top plate sleeves (211), bottom plate sleeves (231) and intermediate sleeves are arranged correspondingly and form a sleeve structure for installing cylindrical batteries. The top plate sleeves (211) on the heat-absorbing top plate (21) are connected to each other through the upper connecting plate (217) along the air-cooling flow direction, and the bottom plate sleeves (231) on the heat-absorbing bottom plate (23) are connected to each other through the lower connecting plate (235) along the air-cooling flow direction; the upper connecting plate (217) and the lower connecting plate (235) are used to enhance the heat conduction between the cylindrical batteries.

2. The power battery module based on PCM heat absorption plate heat dissipation according to claim 1, characterized in that, The heat-absorbing top plate (21) is provided with a liquid injection pipe (215), which is used to inject PCM phase change material into the hollow cavity (233) for maintenance and heat dissipation; the heat-absorbing top plate (21) is provided with an exhaust hole (214), which is used to exhaust the heat-absorbing plate (2) during the liquid injection process; the heat-absorbing bottom plate (23) is provided with an exhaust blind hole (234) corresponding to the exhaust hole (214) on the heat-absorbing top plate (21), which is used to seal and reinforce the top plate sleeve (211), the thermally conductive porous structure (22) and the heat-absorbing bottom plate (23) after the liquid injection is completed by connecting with the nut (213).

3. The power battery module based on PCM heat absorption plate heat dissipation according to claim 2, characterized in that, The heat-absorbing top plate (21) is provided with fins (212) connected to or not connected to the sleeve for air cooling.

4. The power battery module based on PCM heat absorption plate heat dissipation according to claim 2, characterized in that, The top plate sleeve (211) and the bottom plate sleeve (231) are arranged in a straight line on the heat-absorbing top plate (21) and the heat-absorbing bottom plate (23); or The top plate sleeve (211) and the bottom plate sleeve (231) are arranged in an alternating pattern on the heat-absorbing top plate (21) and the heat-absorbing bottom plate (23).

5. The power battery module based on PCM heat absorption plate heat dissipation according to claim 2 or 3, characterized in that, The inner surfaces of the top plate sleeve (211) and the bottom plate sleeve (231) are provided with thermally conductive silicone that is in close contact with the battery.

6. The power battery module based on PCM heat absorption plate heat dissipation according to claim 2, characterized in that, The bottom sleeve (231) has inner and outer layer structures. The outer layer structure is aligned with the top sleeve (211), and the inner layer structure is used to support the cylindrical battery placed inside the sleeve structure.

7. The power battery module based on PCM heat absorption plate heat dissipation according to claim 6, characterized in that, The PCM phase change material is organic paraffin, and the heat-absorbing top plate (21) and heat-absorbing bottom plate (23) are made of aluminum alloy.

8. The power battery module based on PCM heat absorption plate heat dissipation according to claim 2, characterized in that, The outer material of the heating strip (4) is polyimide, and several openings (41) slightly larger than the bottom sleeve (231) are provided on the heating strip (4).

9. The power battery module based on PCM heat absorption plate heat dissipation according to claim 2, characterized in that, The bottom plate sleeve (231) has an enlarged surface welded extension surface (232) that is tightly connected to the top plate (21).

10. The power battery module based on PCM heat absorption plate for heat dissipation according to claim 2, characterized in that, The top and bottom of the PCM heat absorber plate (2) are provided with heat dissipation fins.

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