Freely-assembled square lithium battery thermal management system coupling phase change cooling and air cooling heat dissipation

Abstract

The application discloses a square lithium battery thermal management system which can be freely assembled and is coupled with phase change cooling and air cooling heat dissipation, comprising a square lithium battery, a stepped phase change cooling assembly, an air cooling channel and an end cover. The stepped phase change cooling assembly is designed in combination with the high temperature feature of the lithium battery electrode, and air cooling is performed through the channels naturally formed between the phase change cooling assemblies to form integrated design of phase change cooling and air cooling. The phase change assembly is designed in a single piece, and can be freely assembled according to the quantity demand of the lithium battery. The phase change cooling assembly adopts high-thermal-conductivity foam copper-paraffin composite phase change material to quickly and uniformly absorb the heat generated by the lithium battery during operation, so that the surface temperature of the battery is uniform and constant. Meanwhile, the air cooling channel dissipates part of the heat absorbed by the phase change material to the environment, prolongs the effective temperature control time of the phase change material, and timely realizes regeneration of the phase change material. The application has the advantages of simple structure, small self-weight, free assembly, stable working performance and the like.

Description

Technical Field

[0001] This invention relates to the field of thermal management technology for new energy vehicle batteries, and in particular to a freely assembleable square lithium battery thermal management system that couples phase change cooling and air cooling. Background Technology

[0002] In the field of new energy vehicles, prismatic lithium batteries are one of the most commonly used battery types. However, during use, lithium batteries generate a large amount of heat near the positive and negative electrodes, leading to an increase in their own temperature and uneven temperature distribution throughout the battery. Because of their larger individual cell size, the heat-generating end of the prismatic lithium battery is far from the external casing, and the conductive medium and interface structure are complex, making heat dissipation particularly difficult. If prismatic lithium batteries operate continuously at high temperatures, they are prone to thermal runaway, which can not only damage battery performance but also cause fires, endangering user safety. Therefore, thermal management of lithium batteries is of paramount importance.

[0003] Phase change cooling is one of the effective ways to manage the thermal performance of lithium batteries. It utilizes the characteristic of phase change materials (PCMs) to maintain a constant temperature during the endothermic melting process, thereby cooling the battery surface and keeping the battery temperature uniform and constant. However, traditional PCM thermal management systems suffer from limitations in the heat storage capacity of PCMs. A large amount of PCM is required for long-term operation, resulting in excessive weight. Furthermore, heat is difficult to dissipate after the battery pack is encapsulated, and the temperature continues to rise after the PCM completely melts, losing its cooling capacity. In addition, the heat dissipation rate of the PCM is slow and regeneration is difficult after the battery stops operating. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the traditional phase change cooling thermal management methods and provide a freely assemblable square lithium battery thermal management system that couples phase change cooling and air cooling, so as to achieve long-term effective control of the temperature of square lithium batteries in new energy vehicles and significantly reduce the weight of the cooling components.

[0005] This invention is achieved through the following technical solution:

[0006] A freely assemblable prismatic lithium battery thermal management system coupling phase change cooling and air cooling includes a prismatic lithium battery 1, a stepped phase change cooling assembly 2, an air cooling channel 3, and an end cap 4. The two sides of the prismatic lithium battery 1 are tightly fitted to the phase change cooling assembly 2. The upper half of the prismatic lithium battery 1 near the electrode side is in close contact with the thicker end of the stepped phase change cooling assembly 2, while the lower half of the prismatic lithium battery 1 away from the electrode side is in close contact with the thinner end of the stepped phase change cooling assembly 2. The heat generated by the battery is absorbed by the stepped phase change cooling assembly 2. The thicker ends of the two stepped phase change cooling assemblies 2 between two adjacent prismatic lithium batteries 1 are in close contact, and an air cooling channel 3 is formed between the thinner ends to exchange the heat absorbed by the stepped phase change cooling assembly 2 with the air. The stepped phase change cooling assembly 2 adopts a plate-type unit structure, which can be freely assembled with the prismatic lithium battery 1. Two stepped phase change cooling assemblies 2 and one prismatic lithium battery 1 form a repeating symmetrical unit, and multiple units repeat to form a battery pack. The end cap 4 is used to fix the battery pack.

[0007] The end cap 4 is an integral slot structure. The metal plates at both ends of the end cap are located on the outside of the stepped phase change cooling components 2 on both sides of the battery pack, and are used to fix the battery pack. The metal plate at the bottom of the end cap 4 fixes the battery pack below it.

[0008] The stepped phase change cooling assembly 2 adjusts the number of steps and the thickness of the phase change material corresponding to each step according to the amount of heat generated by the square lithium battery 1.

[0009] The stepped phase change cooling component 2 is filled with a high thermal conductivity copper foam-paraffin composite phase change temperature control material. The size and amount of the copper foam-paraffin composite phase change material are adjusted according to the heat dissipation requirements of the battery pack.

[0010] The stepped phase change cooling component 2 uses a lightweight, thin-walled, high thermal conductivity aluminum alloy encapsulation material to reduce the weight of the assembled battery pack.

[0011] The air-cooled channel 3 is naturally formed by two adjacent stepped phase change cooling components, which come into contact with the ambient air to dissipate heat, increase heat dissipation capacity, and extend temperature control time. When the square lithium battery generates a large amount of heat and the ambient temperature is high, it is combined with forced air cooling to achieve a better cooling effect.

[0012] The end cap 4 is made of lightweight, thin-walled, high thermal conductivity aluminum alloy material. It is designed to fit the number of battery packs and tightly fixes multiple square lithium batteries and stepped phase change cooling components together.

[0013] Advantages of this invention: This invention provides a freely assemblable square lithium battery thermal management system based on coupled phase change cooling and air cooling, featuring an ingenious and novel structural design. The phase change cooling component, taking into account the battery's heat generation characteristics, adopts a plate-type unit structure design, allowing for free assembly and the formation of natural air cooling channels. While achieving uniform and rapid temperature control, it reduces weight, fully combining the advantages of phase change cooling and air cooling. In terms of temperature control, the phase change cooling component maintains a constant and uniformly distributed battery surface temperature when it reaches the melting temperature of the phase change material. Simultaneously, the formation of air cooling channels enhances heat dissipation capacity, extends the time to reach the heat storage limit of the phase change material, and can be combined with a forced air cooling system to handle extreme operating conditions. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a freely assemblable square lithium battery thermal management system based on coupled phase change cooling and air cooling according to the present invention.

[0015] Figure 2 This is a schematic diagram of the repeating symmetrical unit in a freely assemblable square lithium battery thermal management system based on coupled phase change cooling and air cooling, according to the present invention. Detailed Implementation

[0016] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0017] like Figure 1 The diagram illustrates a freely assemblable prismatic lithium battery thermal management system based on coupled phase change cooling and air cooling. The system includes a prismatic lithium battery 1, a stepped phase change cooling assembly 2, an air cooling channel 3, and an end cap 4. The upper half of the prismatic lithium battery 1, near the electrode side, is in close contact with the thicker end of the stepped phase change cooling assembly 2; the lower half of the prismatic lithium battery 1, near the side away from the electrode, is in close contact with the thinner end of the stepped phase change cooling assembly 2. The phase change cooling assembly 2 adopts a plate-type unit structure and can be freely assembled. The air cooling channel 3 is naturally formed by two adjacent stepped phase change cooling assemblies 2, contacting ambient air for heat dissipation, increasing heat dissipation capacity, and extending temperature control time. When the prismatic lithium battery has a high heat generation capacity and the ambient temperature is high, it is combined with forced air cooling to achieve a better cooling effect. Two stepped phase change cooling assemblies 2 and one prismatic lithium battery 1 form repeating symmetrical units, and multiple units repeat to form a battery pack. The focus of this invention is on a square lithium battery thermal management system that combines a stepped phase change cooling component 2 and a wind-cooling channel 3 for coupled heat dissipation. Therefore, the internal mesh structure of the phase change cooling component 2 is omitted from the figure and is not shown. The freely assemblable square lithium battery thermal management system based on coupled phase change cooling and wind-cooling provided in this embodiment can be considered as consisting of multiple... Figure 2 The repeated symmetric unit shown is composed of, Figure 1For ease of demonstration, only the battery pack consisting of 4 repeating symmetrical units is shown; the actual number could be more.

[0018] In a preferred embodiment of the present invention, the end cap 4 is an integral slot structure. The metal plates at both ends of the end cap are located on the outside of the stepped phase change cooling components 2 on both sides of the battery pack, and are used to fix the battery pack. The metal plate at the bottom of the end cap 4 fixes the battery pack below it. The end cap 4 is made of lightweight, thin-walled, high thermal conductivity aluminum alloy material, and is designed to fit the number of battery packs, tightly fixing multiple square lithium batteries and stepped phase change cooling components together.

[0019] In a preferred embodiment of the present invention, the stepped phase change cooling component 2 is filled with a foamed copper-paraffin composite phase change temperature control material with high thermal conductivity, which has high heat storage density and good thermal conductivity.

[0020] As a preferred embodiment of the present invention, the outer shell of the stepped phase change cooling component 2 is made of lightweight, thin-walled, high thermal conductivity aluminum alloy packaging material to reduce the weight of the assembled battery pack.

[0021] like Figure 1 As shown, the working method of a freely assemblable square lithium battery thermal management system based on coupled phase change cooling and air cooling is as follows:

[0022] When the square lithium battery 1 is working, the large amount of heat generated in the upper part near the electrode side is transferred to the phase change material through the foamed copper inside the stepped phase change cooling component 2. The phase change material absorbs heat by melting, keeping the surface temperature of the square lithium battery constant and uniformly distributed at its melting point. At the same time, the air-cooling channel can dissipate the heat absorbed by the phase change material to the environment, extending the temperature control time. It can also be combined with a forced air-cooling system to cope with extreme operating conditions, achieving effective temperature control in the thermal management application of square lithium batteries in new energy vehicles.

[0023] The above embodiments only provide a detailed description of the technical solution of the present invention, and this specification should not be construed as limiting the present invention. For those skilled in the art, various modifications can still be made to these embodiments. Any modifications made within the scope of the disclosed principles of the present invention, including equivalent substitutions and improvements, should be included within the protection scope of the present invention.

Claims

1. A freely assemblable prismatic lithium battery thermal management system that couples phase change cooling and air cooling, characterized in that: It includes a square lithium battery (1), a stepped phase change cooling assembly (2), an air-cooling channel (3), and an end cap (4); the square lithium battery (1) is tightly fitted to the phase change cooling assembly (2) on both sides, the upper half of the square lithium battery (1) near the electrode is in close contact with the thicker end of the stepped phase change cooling assembly (2), and the lower half of the square lithium battery (1) away from the electrode is in close contact with the thinner end of the stepped phase change cooling assembly (2). The heat generated by the battery is absorbed by the stepped phase change cooling assembly (2); adjacent The thicker ends of the two stepped phase change cooling components (2) between the two square lithium batteries (1) are in close contact, and the thinner ends form a cooling channel (3) to exchange the heat absorbed by the stepped phase change cooling components (2) with the air. The stepped phase change cooling components (2) adopt a plate-type unit structure and can be freely assembled with the square lithium batteries (1). The two stepped phase change cooling components (2) and one square lithium battery (1) form a repeating symmetrical unit, and multiple units repeat to form a battery pack. The end cap (4) is used to fix the battery pack.

2. The freely assemblable square lithium battery thermal management system with coupled phase change cooling and air cooling as described in claim 1, characterized in that: The end cap (4) is an integral slot structure. The metal plates at both ends of the end cap are on the outside of the stepped phase change cooling components (2) on both sides of the battery pack, and are used to fix the battery pack. The metal plate at the bottom of the end cap (4) fixes the battery pack below the battery pack.

3. The freely assemblable square lithium battery thermal management system with coupled phase change cooling and air cooling as described in claim 1, characterized in that: The stepped phase change cooling assembly (2) adjusts the number of steps and the thickness of the phase change material corresponding to each step according to the amount of heat generated by the square lithium battery (1).

4. The freely assemblable square lithium battery thermal management system with coupled phase change cooling and air cooling as described in claim 1, characterized in that: The stepped phase change cooling component (2) is filled with a high thermal conductivity copper foam-paraffin composite phase change temperature control material. The size and amount of the copper foam-paraffin composite phase change material are adjusted according to the heat dissipation requirements of the battery pack.

5. The freely assemblable square lithium battery thermal management system with coupled phase change cooling and air cooling as described in claim 1, characterized in that: The stepped phase change cooling component (2) uses a lightweight, thin-walled, high thermal conductivity aluminum alloy encapsulation material to reduce the weight of the assembled battery pack.

6. The freely assemblable square lithium battery thermal management system with coupled phase change cooling and air cooling as described in claim 1, characterized in that: The air-cooled channel (3) is naturally formed by two adjacent stepped phase change cooling components. It comes into contact with the ambient air to dissipate heat, increase heat dissipation capacity, and extend the temperature control time. When the square lithium battery generates a large amount of heat and the ambient temperature is high, it is combined with forced air cooling to achieve a better cooling effect.

7. The freely assemblable square lithium battery thermal management system with coupled phase change cooling and air cooling as described in claim 1, characterized in that: The end cap (4) is made of lightweight, thin-walled, high thermal conductivity aluminum alloy material. The size is designed to fit the number of battery packs, and multiple square lithium batteries and stepped phase change cooling components are tightly fixed together.

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