Composite fin cooperates with liquid cooling square battery thermal management system

Abstract

The application discloses a square battery thermal management system with composite fins and liquid cooling, comprising a lithium battery pack composed of multiple square battery monomers connected in series, a flat heat pipe, composite fins, phase change material and a liquid cooling pipe. The lithium battery pack comprises multiple square battery monomers connected in series by conductive sheets; the flat heat pipe is inserted between the square battery monomers; the lithium battery pack is provided with composite fins on both sides; the two ends of the flat heat pipe are clamped in the fins; the phase change material is filled between adjacent fins and in the hollow fin base; the liquid cooling pipe is inserted in the fin base, and the liquid cooling pipe is filled with cooling liquid. The composite fins can effectively dissipate heat of the lithium battery pack, improve the thermal management efficiency, reduce the energy consumption of the system, and realize safe and reliable operation of the battery pack through liquid cooling even under severe working conditions. Meanwhile, the system is detachable and convenient to maintain.

Description

Technical Field

[0001] This invention relates to the field of lithium battery thermal management technology, specifically to a square battery thermal management system with composite fins and liquid cooling. Background Technology

[0002] Lithium-ion batteries are widely used in power batteries and electrochemical energy storage due to their advantages such as high energy density, long cycle life, and low self-discharge rate. Among them, prismatic batteries are one of the most commonly used battery types due to their high packaging reliability, light weight, and simple structure. However, lithium-ion batteries generate a relatively high amount of heat, which can easily accumulate during operation, leading to a rapid temperature rise and even thermal runaway. Furthermore, the large volume of prismatic batteries can cause uneven temperature distribution in individual cells and the battery pack, resulting in rapid battery life degradation and serious safety issues. Therefore, reasonable and effective thermal management of battery packs is essential.

[0003] Traditional battery thermal management methods include air cooling and liquid cooling, as well as heat pipe cooling and phase change cooling. Each single thermal management method has its drawbacks. For example, air cooling is simple in structure and low in cost, but it is bulky, has low heat dissipation efficiency, and high energy consumption; liquid cooling is highly efficient, but suffers from poor temperature uniformity and high energy consumption. Heat pipe cooling and phase change cooling are passive heat dissipation methods that do not require additional energy, but they need to be combined with active cooling technologies to expand their applicability. Combining the advantages of different thermal management methods to adapt to the thermal management requirements of different operating conditions is the future direction of development.

[0004] Therefore, a new thermal management system is needed to solve the problems of low thermal management efficiency, high energy consumption, limited applicable operating conditions, and difficult maintenance in existing technologies. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention provides a square battery thermal management system with composite fins and liquid cooling, aiming to solve problems such as low thermal management efficiency, high energy consumption, limited applicable operating conditions, and difficult maintenance in existing technologies.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A thermal management system for a square battery with composite fins and liquid cooling, comprising a lithium battery pack composed of multiple square battery cells connected in series, a flat heat pipe, fins, a phase change material, and a liquid cooling pipe.

[0008] The lithium battery pack includes multiple square battery cells connected in series with conductive sheets.

[0009] Flat heat pipes are inserted between the square battery cells;

[0010] The lithium battery pack has composite fins on both sides.

[0011] The two ends of the flat heat pipe are clamped in the fin teeth, and the space between adjacent fin teeth and the hollow fin base are filled with phase change material.

[0012] Liquid cooling pipes are inserted into the finned base, and the liquid cooling pipes are filled with coolant.

[0013] Furthermore, the battery cells are square lithium batteries, which are connected in series with each other by conductive sheets.

[0014] Furthermore, the flat heat pipe is inserted between the square battery cells and is attached to the surface of the square battery cells.

[0015] Furthermore, the lithium battery pack is provided with symmetrically distributed composite fins on both sides. The structure of the composite fins includes fin teeth, phase change material, fin base, liquid cooling pipe and base cover plate.

[0016] Furthermore, the two ends of the flat heat pipe are clamped between the fin teeth of the composite fins, and are tightly fitted with the fin teeth;

[0017] The adjacent fin teeth of the composite fin are filled with phase change material;

[0018] The base of the composite fin is a hollow structure filled with phase change material.

[0019] Furthermore, a circular "M"-shaped liquid cooling pipe is inserted into the phase change material of the finned base, with the lower end of the liquid cooling pipe being the coolant inlet and the upper end being the coolant outlet.

[0020] Furthermore, the lithium battery pack thermal management system also includes an electronic control module, which can control the flow of coolant under different operating conditions, and activate liquid cooling for heat dissipation in high-temperature environments (above the phase change temperature of the phase change material, generally above 45°C) and when the battery pack is charged and discharged at high rates (above 2C).

[0021] Optionally, the coolant is a 50% (by volume) aqueous solution of ethylene glycol, the phase change material is a mixture of expanded graphite and paraffin wax, and the fins and the liquid cooling pipe are both made of aluminum.

[0022] Furthermore, the composite fins, flat heat pipes, and battery pack are detachable and installable.

[0023] The present invention has the following advantages:

[0024] Under normal operating conditions, the lithium battery pack's temperature is controlled via flat heat pipes and composite fins. The heat absorbed by the heat pipes is rapidly dissipated by the phase change material and fins, improving heat dissipation efficiency and temperature uniformity of the battery pack. This achieves efficient thermal management without the need for active heat exchange technology, reducing system energy consumption. When the battery pack discharges at high rates at ambient temperatures exceeding the phase change temperature, the liquid cooling system enables rapid heat dissipation, meeting the thermal management requirements under harsh conditions. The composite fins, heat pipes, and battery pack are all detachable and installable, making maintenance more convenient. Attached Figure Description

[0025] Figure 1 This is a three-dimensional structural schematic diagram of the present invention;

[0026] Figure 2 This is an exploded view of the overall structure of the present invention;

[0027] Figure 3 This is a schematic diagram of the heat pipe and composite fin structure of the present invention;

[0028] Figure 4 This is an exploded view of the composite fins of the present invention;

[0029] Figure 5 This is a comparison chart of the cooling effects of the present invention and the heatless management system at room temperature;

[0030] Figure 6 This is a diagram showing the temperature control results of liquid cooling switching at high temperatures according to the present invention.

[0031] The attached figures are labeled as follows:

[0032] 100-Composite fins, 101-Phase change material, 102-Coolant outlet, 103-Coolant inlet, 104-Fin teeth, 105-Fin base, 106-Liquid cooling pipe, 107-Base cover plate, 200-Flat heat pipe, 300-Battery pack, 310-Battery cell, 400-Conductive sheet. Detailed Implementation

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] The following description is provided to enable any person skilled in the art to implement and use the present invention. In this description, details are set forth for purposes of explanation. It should be understood that those skilled in the art will recognize that the invention can be implemented without these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the invention with unnecessary detail. Therefore, the invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope accorded to the principles and features disclosed herein.

[0035] This invention provides a thermal management system for a square battery with composite fins and liquid cooling, which will be described in detail below.

[0036] like Figures 1-4 As shown, this invention discloses a thermal management system for a square battery with composite fins and synergistic liquid cooling, comprising: a lithium battery pack 300 composed of multiple square battery cells 310 connected in series, a flat heat pipe 200, composite fins 100, a phase change material 101, and a liquid cooling pipe 106; the composite fin structure includes fin teeth 104, phase change material 101, fin base 105, liquid cooling pipe 106, and base cover plate 107. The lithium battery pack 300 includes multiple square battery cells 310 connected in series by conductive sheets 400; flat heat pipes 200 are inserted between the square battery cells 310; composite fins 100 are arranged on both sides of the lithium battery pack 300; the two ends of the flat heat pipe 200 are clamped in the fin teeth 104, and the space between adjacent fin teeth 104 and the hollow fin base 105 are filled with phase change material 101; the liquid cooling pipe 106 is inserted into the fin base 105 and filled with coolant. Multiple fin teeth 104 are arranged at intervals on the fin base 105.

[0037] Under normal operating conditions, this invention controls the temperature of the lithium battery pack 300 through a flat heat pipe 200 and composite fins 100. The battery heat absorbed by the flat heat pipe 200 is rapidly dissipated by the phase change material 101 and composite fins 100, improving heat dissipation efficiency and temperature uniformity of the battery pack 300. High-efficiency thermal management is achieved without the need for active heat exchange technology, reducing system energy consumption. When the battery pack 300 discharges at a high rate at ambient temperatures exceeding the phase change temperature, the liquid cooling system enables rapid heat dissipation, meeting the thermal management requirements under harsh operating conditions. The composite fins 100, flat heat pipe 200, and battery pack 300 are all detachable and installable, making maintenance more convenient.

[0038] Specifically, such as Figure 1 As shown, the battery cell 310 is a square lithium battery, which is connected in series with each other by conductive sheets 400.

[0039] Preferably, the battery cells 310 are arranged at intervals of 1 mm to facilitate the arrangement of the flat heat pipes 200.

[0040] Specifically, such as Figure 1 and Figure 3 As shown, the flat heat pipe 200 is inserted between the square battery cells 310 and is attached to the surface of the square battery cells 310.

[0041] Furthermore, such as Figure 1 and Figure 2 As shown, the lithium battery pack 300 has symmetrically distributed composite fins 100 on both sides.

[0042] Specifically, such as Figure 3 and Figure 4 As shown, the two ends of the flat heat pipe 200 are sandwiched between the fin teeth 104 of the composite fin 100 and are tightly fitted with the fin teeth 104; the adjacent fin teeth 104 of the composite fin 100 are filled with phase change material 101; the fin base 105 of the composite fin 100 is a hollow structure, filled with phase change material 101, and sealed by the base cover plate 107.

[0043] Preferably, the length of the fin tooth 104 is 10 mm, and the thickness of the fin base 105 is 7.5 mm.

[0044] Specifically, such as Figure 4 As shown, a circular "M"-shaped liquid cooling pipe 106 is inserted into the phase change material 101 of the finned base 105. The lower end of the liquid cooling pipe 106 is the coolant inlet 103, and the upper end is the coolant outlet 102.

[0045] Furthermore, the battery thermal management system also includes an electronic control module that can control the flow of coolant under different operating conditions.

[0046] Specifically, when the ambient temperature is low or the battery pack is charged and discharged at a low rate of 300, the coolant in the liquid cooling pipe 106 is stopped, and heat dissipation is carried out by a completely passive heat exchange method to minimize energy consumption. Figure 5 As shown, when the battery pack is discharged at 2C at 25°C, the highest temperature of the passive heat exchange system is reduced by 12°C compared to the system without a heat exchange system, and the maximum temperature difference is reduced by 3°C. When the ambient temperature exceeds the phase change temperature of the phase change material 101 and the battery pack is charged and discharged at a high rate of 300, the flow of coolant in the liquid cooling pipe 106 is controlled to remove the rapidly generated heat in the system, such as... Figure 6 As shown, even at a high temperature of 40℃, the composite fins combined with liquid cooling can still keep the maximum temperature of the battery pack below the dangerous threshold, demonstrating excellent thermal management performance.

[0047] Furthermore, such as Figure 2 and Figure 4As shown, the battery pack 300, flat heat pipe 200, phase change material 101, fins 104 and fin base 105, liquid cooling pipe 106 and base cover 107 are detachably connected, which facilitates the maintenance of the thermal management system.

[0048] Preferably, in order to reduce costs, lighten the weight of the thermal management system, and improve heat exchange efficiency, the coolant is a 50% volume percentage aqueous solution of ethylene glycol, the phase change material is a mixture of expanded graphite and paraffin, and the composite fins 100 and the liquid cooling pipes 106 are both made of aluminum.

[0049] To better understand this invention, the working principle of this invention will be described in full below:

[0050] During normal operation, the heat generated by the lithium battery pack 300 is absorbed by the flat heat pipe 200, which is in close contact with it. The flat heat pipe 200 quickly transfers the absorbed heat to both ends. The fin teeth 104 of the composite fins 100 can conduct heat to the fin base 105, where it can be absorbed by the phase change material 101 between adjacent fin teeth and the phase change material 101 filling the fin base 105. The large contact area between the flat heat pipe 200 and the square battery cell 310 ensures the temperature uniformity of the battery pack 300. This entire process does not require active heat exchange technology, thus reducing energy consumption. When the ambient temperature is higher than the phase change temperature of the phase change material 101 and the battery pack 300 is charged and discharged at a high rate, the phase change material fails and cannot absorb the heat at both ends of the heat pipe. At this time, the liquid cooling system is activated, and the coolant flowing in the liquid cooling pipe 106 quickly dissipates the large amount of heat generated to meet the thermal management requirements.

[0051] The foregoing has provided a detailed description of a composite finned liquid-cooled square battery thermal management system provided by the embodiments of the present invention. Specific examples have been used to illustrate the principles and implementation methods of the invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A thermal management system for a square battery with composite fins and synergistic liquid cooling, characterized in that, A lithium battery pack consisting of multiple square battery cells connected in series, a flat heat pipe, composite fins, phase change materials, and a liquid cooling pipe; The lithium battery pack includes multiple square battery cells connected in series with conductive sheets. Flat heat pipes are inserted between the square battery cells; The lithium battery pack has composite fins on both sides. The two ends of the flat heat pipe are clamped in the fin teeth of the composite fin, and phase change material is filled between adjacent fin teeth and in the hollow fin base. Liquid cooling pipes are inserted into the finned base, and the liquid cooling pipes are filled with coolant; The composite fin structure includes fin teeth, phase change material, fin base, liquid cooling pipe and base cover plate; the base of the composite fin is a hollow structure and is filled with phase change material.

2. The thermal management system for a square battery with composite fins and synergistic liquid cooling according to claim 1, characterized in that, The battery cells are square lithium batteries, which are connected in series with each other by conductive sheets.

3. The thermal management system for a square battery with composite fins and synergistic liquid cooling according to claim 1, characterized in that, The flat heat pipes are inserted between the square battery cells and are attached to the surface of the square battery cells.

4. The thermal management system for a square battery with composite fins and synergistic liquid cooling according to claim 1, characterized in that, The lithium battery pack has symmetrically distributed composite fins on both sides.

5. A thermal management system for a square battery with composite fins and synergistic liquid cooling according to claim 3, characterized in that, The two ends of the flat heat pipe are clamped between the fin teeth of the composite fins and are in close contact with the fin teeth; The adjacent fin teeth of the composite fin are filled with phase change material.

6. A thermal management system for a square battery with composite fins and synergistic liquid cooling according to claim 5, characterized in that, A circular "M"-shaped liquid cooling pipe is inserted into the phase change material of the finned base. The lower end of the liquid cooling pipe is the coolant inlet, and the upper end is the coolant outlet.

7. A thermal management system for a square battery with composite fins and synergistic liquid cooling according to claim 6, characterized in that, The battery thermal management system also includes an electronic control module, which can control the flow of coolant under different operating conditions, and activate liquid cooling when the temperature is above 45°C and the battery pack is charged or discharged at a rate of 2C or higher.

8. A thermal management system for a square battery with composite fins and synergistic liquid cooling according to claim 1, characterized in that, The coolant is a 50% (by volume) aqueous solution of ethylene glycol, the phase change material is a mixture of expanded graphite and paraffin, and the fins and the liquid cooling pipe are both made of aluminum.

9. A thermal management system for a square battery with composite fins and synergistic liquid cooling according to claim 1, characterized in that, The composite fins, flat heat pipes, and battery pack are detachable and installable.

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