A liquid-cooled phase change hybrid battery thermal management system and its implementation method

Abstract

This invention discloses a liquid-cooled phase change hybrid battery thermal management system, including a battery cell, a housing, and a first liquid cooling plate and a second liquid cooling plate disposed at the upper and lower ends of the battery cell. The housing is composed of several hexagonal shells arranged in a honeycomb pattern, with each battery cell placed inside a hexagonal shell. A phase change material is filled between the battery cell and the hexagonal shell. Ribs are provided at the midpoints of the six surfaces of the hexagonal shell, with one end of the rib directly contacting the battery cell and the other end extending towards the hexagonal shell, thereby dividing the phase change material into six equal parts. The first liquid cooling plate and the second liquid cooling plate are connected by a liquid cooling channel. The first liquid cooling plate has a working fluid inlet, and the second liquid cooling plate has a working fluid outlet. The working fluid flows in from the working fluid inlet of the first liquid cooling plate, flows through the liquid cooling channel to the second liquid cooling plate at the lower end of the battery cell, and finally flows out from the working fluid outlet. This invention rationally couples phase change material cooling and liquid cooling, resulting in a compact battery module structure that is easy to install and has a simple structure.

Description

Technical Field

[0001] This invention relates to the field of battery thermal management technology, specifically to a liquid-cooled phase change hybrid battery thermal management system and its implementation method. Background Technology

[0002] Power batteries are the core components of electric vehicles. Among them, lithium-ion batteries are widely used in the electric vehicle field due to their unique advantages such as high energy density, long cycle life, lightweight, and environmental friendliness. However, lithium-ion batteries generate heat during charging and discharging, leading to temperature increases and inconsistencies in cell temperature. If heat accumulates and cannot be dissipated efficiently, it can easily cause a vicious cycle of "high temperature-high heat-high temperature," which can lead to thermal runaway in severe cases. Therefore, an efficient battery thermal management system with excellent temperature uniformity and control performance is crucial to maintaining lithium batteries within their optimal operating temperature range (15℃ to 35℃) and enabling them to output their best performance.

[0003] Current research on thermal management systems primarily focuses on three cooling methods: air cooling, liquid cooling, and phase change material (PCM) cooling. Air cooling is no longer sufficient for the high demands of batteries, while liquid cooling offers high heat dissipation efficiency but is complex and prone to leakage. Furthermore, even with promising PCM cooling, conventional PCMs have very low thermal conductivity and are prone to leakage. To better meet the heat dissipation requirements of high-energy-density batteries, coupled systems using two or more of these thermal management methods have become a research hotspot, enabling further improvement and refinement of thermal management systems. Therefore, this invention proposes a liquid-cooled phase change hybrid battery thermal management system and its implementation method. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings and deficiencies of the prior art and provide a liquid-cooled phase change hybrid battery thermal management system and its implementation method. The system uses a first liquid-cooled plate and a second liquid-cooled plate distributed vertically, which are connected by a liquid-cooled channel. The system also has a meandering structure channel inside, in order to solve the problems mentioned in the background art.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A liquid-cooled phase change hybrid battery thermal management system includes battery cells connected in series and parallel to form a battery module, and also includes a casing and a first liquid cooling plate and a second liquid cooling plate disposed at the upper and lower ends of the battery cells.

[0007] The outer shell is composed of several hexagonal shells arranged in a honeycomb pattern. Each battery cell is placed in a hexagonal shell, and phase change material is filled between the battery cell and the hexagonal shell. Ribs are provided at the midpoints of the six surfaces of the hexagonal shell. One end of the rib is in direct contact with the battery cell, and the other end extends toward the hexagonal shell, thereby dividing the phase change material into six equal parts.

[0008] The first liquid cooling plate and the second liquid cooling plate are connected by a liquid cooling channel. The first liquid cooling plate is provided with a working fluid inlet and the second liquid cooling plate is provided with a working fluid outlet. The working fluid flows in from the working fluid inlet of the first liquid cooling plate, flows through the liquid cooling channel to the second liquid cooling plate at the lower end of the cell, and finally flows out from the working fluid outlet.

[0009] Furthermore, the liquid cooling channels are vertically distributed in the outer casing, parallel to the battery cell, and are located at the six vertices of the hexagonal casing.

[0010] Furthermore, the first and second liquid cooling plates are provided with a meandering structural channel inside, in which the working fluid diffuses. The inflow and outflow of the liquid cooling channel are located in the path of the meandering structural channel, and the meandering structural channel is connected to the working fluid inlet and the working fluid outlet, respectively.

[0011] Furthermore, the meandering structural channel bends to form a meandering S-shaped structure, allowing the working fluid to flow through the top or bottom of each cell.

[0012] As a preferred embodiment, the outer casing is made of a material with high thermal conductivity, specifically aluminum or copper.

[0013] As a preferred embodiment, the phase change material is an insulating, flame-retardant, and three-dimensional high thermal conductivity composite phase change material, specifically a metal foam, a porous polymer, a carbon-based three-dimensional porous material, or a porous ceramic material.

[0014] As a preferred embodiment, the cooling medium in the liquid cooling channel during high-temperature heat dissipation is air, liquid water, ethylene glycol, or gallium-based alloy liquid metal, while the working medium during low-temperature heating is boiling water.

[0015] This invention also provides a method for implementing a liquid-cooled phase-change hybrid battery thermal management system, comprising:

[0016] When the battery cell operates in a high-temperature environment, it generates a large amount of heat during charging and discharging, causing the battery pack temperature to rise continuously. Part of the heat generated by the cell is transferred to the phase change material (PCM) through heat conduction, raising the PCM's temperature. Another part exchanges heat with the first and second liquid cooling plates, achieving further cooling. Meanwhile, the heat from the PCM is partially exchanged through direct contact with the first and second liquid cooling plates, and partially dissipated through the outer shell and fins, achieving secondary heat dissipation and enhancing overall cooling. Furthermore, a cooling medium is added to the working fluid inlet. After entering the first liquid cooling plate, the cooling medium flows rapidly through a meandering channel, then through vertically distributed liquid cooling channels to the second liquid cooling plate. It then flows through meandering pipes within the second liquid cooling plate and finally exits the system from the working fluid outlet. A portion of the heat from the outer shell is carried away by the liquid cooling channels, while the remaining portion diffuses into the air.

[0017] In a low-temperature environment, the heating medium is introduced into the first liquid cooling plate and flows rapidly in the meandering structural channel of the first liquid cooling plate. Then it flows from the liquid cooling channel to the second liquid cooling plate, and then flows in the meandering structural pipe in the second liquid cooling plate. Finally, it flows out of the system from the working medium outlet, thus achieving low-temperature heating.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] The battery thermal management system of this invention rationally couples phase change material cooling and liquid cooling together, resulting in a compact battery module structure that is easy to install and has a simple design. Each battery cell is placed within a hexagonal shell, with phase change material filling the space between the cell and the shell. Ribs are positioned at the midpoints of the six surfaces of the hexagonal shell. One end of each rib directly contacts the battery cell, while the other end extends towards the hexagonal shell, thus dividing the phase change material into six equal parts. Direct contact with the battery cell allows the phase change material to quickly remove heat. The ribs, with one end cutting into the phase change material, not only directly absorb heat but also divide the material into six equal parts, enhancing heat transfer and evenly distributing heat from the battery cell to each hexagonal shell, achieving multi-directional heat dissipation and preventing localized overheating within the thermal management system, ensuring temperature uniformity. Furthermore, this invention incorporates a first liquid cooling plate and a second liquid cooling plate at the top and bottom of the battery cell. The first liquid cooling plate and the second liquid cooling plate... The liquid cooling plates are connected by liquid cooling channels. The first liquid cooling plate has a working fluid inlet, and the second liquid cooling plate has a working fluid outlet. The working fluid flows in from the working fluid inlet of the first liquid cooling plate, flows through the liquid cooling channel to the second liquid cooling plate at the bottom of the cell, and finally flows out from the working fluid outlet. The first and second liquid cooling plates, located at the top and bottom of the cell, not only absorb the heat from the cell's electrodes, but also have a meandering channel structure inside them. The meandering channel structure bends to form an S-shape, allowing the working fluid to flow through the top or bottom of each cell, ensuring the temperature consistency of the cell electrodes. High-temperature heat dissipation and low-temperature heating are achieved by adding different working fluids. In addition, the first and second liquid cooling plates are connected by liquid cooling channels. The working fluid enters vertically from the first liquid cooling plate into the second liquid cooling plate, so that the working fluid can not only diffuse horizontally on the cell electrodes, but also flow through the vertical liquid cooling channels surrounding the cell, enhancing the heat transfer effect and realizing multi-directional thermal management of the cell. Attached Figure Description

[0020] Figure 1 An exploded view showing the overall structural connections of the liquid-cooled phase-change hybrid battery thermal management system proposed in this invention.

[0021] Figure 2 This is a schematic diagram of the overall structure of the liquid-cooled phase change hybrid battery thermal management system proposed in this invention;

[0022] Figure 3This is a schematic diagram of a partial disassembly structure proposed in this invention;

[0023] Figure 4 This is a cross-sectional view of the first liquid cooling plate proposed in this invention;

[0024] Figure 5 This is a diagram showing the working fluid flow direction of the liquid cooling channel proposed in this invention.

[0025] In the diagram: 1. First liquid cooling plate; 2. Working fluid inlet; 3. Outer shell; 4. Liquid cooling channel; 5. Battery cell; 6. Fin; 7. Phase change material; 8. Second liquid cooling plate; 9. Working fluid outlet; 10. Detour-shaped channel. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0027] Please see Figure 1-5 This embodiment provides a technical solution:

[0028] A liquid-cooled phase-change hybrid battery thermal management system includes battery cells 5 connected in series and parallel to form a battery module, and a housing 3, a first liquid cooling plate 1 and a second liquid cooling plate 8 disposed at the upper and lower ends of the battery cells 5. The housing 3 is composed of several hexagonal shells arranged in a honeycomb pattern, with each battery cell 5 placed in a hexagonal shell. A phase change material 7 is filled between the battery cell 5 and the hexagonal shell. Ribs 6 are provided at the midpoints of the six surfaces of the hexagonal shell. One end of the rib 6 is in direct contact with the battery cell 5, and the other end extends towards the hexagonal shell, thereby dividing the phase change material 7 into six equal parts. The first liquid cooling plate 1 and the second liquid cooling plate 8 are connected by a liquid cooling channel 4. The first liquid cooling plate 1 is provided with a working fluid inlet 2, and the second liquid cooling plate 8 is provided with a working fluid outlet 9. The working fluid flows in from the working fluid inlet 2 of the first liquid cooling plate 1, flows through the liquid cooling channel 4 to the second liquid cooling plate 8 at the lower end of the battery cell 5, and finally flows out from the working fluid outlet 9.

[0029] The battery thermal management system of this invention rationally couples the cooling of phase change material 7 and liquid cooling together, resulting in a compact battery module structure that is easy to install and simple in design. Each battery cell 5 is placed within a hexagonal shell, with phase change material 7 filling the space between the cell 5 and the shell. Ribs 6 are located at the midpoints of the six surfaces of the hexagonal shell. One end of each rib 6 directly contacts the cell 5, while the other end extends towards the hexagonal shell, thus dividing the phase change material 7 into six equal parts. The direct contact between the phase change material 7 and the cell 5 allows for rapid heat dissipation. The rib 6, with one end transversely inserted into the phase change material 7, not only directly absorbs the heat emitted by the cell 5 but also divides the phase change material 7 into six equal parts, enhancing heat transfer while uniformly distributing the heat from the cell 5 to each hexagonal shell, achieving multi-directional heat dissipation, preventing localized overheating within the thermal management system, and ensuring temperature uniformity. Furthermore, this invention utilizes a first liquid cooling plate 1 and a second liquid cooling plate 8 at the upper and lower ends of the cell 5, with the first liquid cooling plate 1 and the second liquid cooling plate 8... The cells are connected by a liquid cooling channel 4. The first liquid cooling plate 1 is provided with a working fluid inlet 2, and the second liquid cooling plate 8 is provided with a working fluid outlet 9. The working fluid flows in from the working fluid inlet 2 of the first liquid cooling plate 1, flows through the liquid cooling channel 4 to the second liquid cooling plate 8 at the lower end of the cell 5, and finally flows out from the working fluid outlet 9. The first liquid cooling plate 1 and the second liquid cooling plate 8, which are provided at the upper and lower ends of the cell 5, can not only absorb the heat of the electrode of the cell 5, but also have a meandering structure channel 10 inside them. The meandering structure channel 10 is bent to form an S-shape. The structure allows the working fluid to flow through the top or bottom of each cell 5, ensuring the temperature consistency of the cell 5 terminals. High-temperature heat dissipation and low-temperature heating are achieved by adding different working fluids. In addition, the first liquid cooling plate 1 and the second liquid cooling plate 8 are connected by a liquid cooling channel 4. The working fluid enters the second liquid cooling plate 8 vertically from the first liquid cooling plate 1, so that the working fluid can not only diffuse on the horizontal surface of the cell 5 terminals, but also flow through the vertical liquid cooling channel 4 around the cell 5, which enhances the heat transfer effect and realizes multi-directional thermal management of the cell 5.

[0030] In this embodiment, as Figure 3 and Figure 5 As shown, the liquid cooling channel 4 is vertically distributed in the outer shell 3, parallel to the battery cell 5, and is located at one of the six vertices of the hexagonal shell. In this embodiment, the liquid cooling channel 4 serves as a connecting pipe between the first liquid cooling plate 1 and the second liquid cooling plate 8, vertically surrounding the battery cell 5. This provides an additional layer of liquid cooling channel 4 for heat transfer, in addition to the phase change material 7 and the fins 6 transferring heat on the sidewalls of the battery cell 5. Figure 3 As shown, in addition to the hexagonal shell along the edge of the battery thermal management system, the six vertices of the internal hexagonal shell are equipped with liquid cooling channels 4, which ensures heat transfer in multiple directions, especially when heating at low temperatures.

[0031] In this embodiment, as Figure 4 and Figure 5 As shown, the first liquid cooling plate 1 and the second liquid cooling plate 8 are provided with a meandering structural channel 10 inside, in which the working fluid diffuses. The inflow and outflow of the liquid cooling channel 4 are located in the path of the meandering structural channel 10, and the meandering structural channel 10 is connected to the working fluid inlet 2 and the working fluid outlet 9, respectively. Figure 4 The inflow and outflow of the liquid cooling channel 4 are staggered in the path of the meandering structure channel 10, so as to correspond to the six vertices of the hexagonal shell.

[0032] In this embodiment, as Figure 4 and Figure 5 As shown, the meandering structure channel 10 is bent to form a meandering S-shaped structure, allowing the working fluid to flow through the top or bottom of each cell 5; as Figure 5 The black arrows indicate the direction of the working fluid flow. In this embodiment, when the working fluid is used for high-temperature heat dissipation or low-temperature heating, the working fluid is added to the working fluid inlet 2. After entering the first liquid cooling plate 1, the working fluid flows rapidly in the meandering structure channel 10, flows through the vertically distributed liquid cooling channel 4 to the second liquid cooling plate 8, flows in the meandering structure pipe in the second liquid cooling plate 8, and finally flows out of the system from the working fluid outlet 9.

[0033] To ensure the structural stability of the battery thermal management system, the outer shell 3 is made of a high thermal conductivity material, specifically aluminum or copper; the thermal management system outer shell 3 made of aluminum and copper not only has excellent thermal conductivity, but also good mechanical strength.

[0034] To further improve the heat dissipation efficiency of this embodiment, the phase change material 7 is an insulating, flame-retardant, and three-dimensional high thermal conductivity framework composite phase change material 7, specifically a metal foam, porous polymer, carbon-based three-dimensional porous material, or porous ceramic material; the above materials include, but are not limited to: metal foam (foamed copper, foamed aluminum, foamed nickel) / paraffin / graphite composite phase change material 7, paraffin / nano flame retardant composite phase change material 7, paraffin / carbon nanotube high thermal conductivity composite phase change material 7, paraffin / graphene high thermal conductivity composite phase change material 7, graphene-coated foamed nickel and paraffin composite phase change material 7, porous SiC ceramic / paraffin composite phase change material 7, etc.

[0035] To further improve the heat dissipation and heating efficiency of this embodiment, the cooling medium in the liquid cooling channel 4 during high-temperature heat dissipation is air, liquid water, ethylene glycol, and gallium-based alloy liquid metal, while the working medium during low-temperature heating is boiling water.

[0036] Based on the above technical solutions, this embodiment also proposes a method for implementing a liquid-cooled phase-change hybrid battery thermal management system, including:

[0037] When the battery cell 5 operates in a high-temperature environment, it generates a large amount of heat during charging and discharging, causing the battery pack temperature to rise continuously. Part of the heat generated by the battery cell 5 is transferred to the phase change material 7 through heat conduction, causing the phase change material 7 to heat up. Another part exchanges heat with the first liquid cooling plate 1 and the second liquid cooling plate 8, achieving further cooling. The heat of the phase change material 7 is partly exchanged through direct contact with the first liquid cooling plate 1 and the second liquid cooling plate 8, and partly dissipated through the outer shell 3 and the fins 6, achieving secondary heat dissipation and enhancing the heat dissipation effect. In addition, a cooling working fluid is added to the working fluid inlet 2. After entering the first liquid cooling plate 1, the cooling working fluid flows rapidly in the meandering structure channel 10, flows through the vertically distributed liquid cooling channels 4 to the second liquid cooling plate 8, flows through the meandering structure pipes in the second liquid cooling plate 8, and finally flows out of the system from the working fluid outlet 9. Part of the heat of the outer shell 3 is carried away by the liquid cooling channels 4, and the other part diffuses into the air.

[0038] In a low-temperature environment, a heating medium is introduced into the first liquid cooling plate 1 and flows rapidly in the meandering structural channel 10 of the first liquid cooling plate 1. Then it flows from the liquid cooling channel 4 to the second liquid cooling plate 8, and then flows in the meandering structural pipe in the second liquid cooling plate 8. Finally, it flows out of the system from the working medium outlet 9, thus achieving low-temperature heating.

[0039] The above are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above content. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A liquid-cooled phase-change hybrid battery thermal management system, comprising battery cells connected in series and parallel to form a battery module, characterized in that, It also includes an outer casing, a first liquid cooling plate and a second liquid cooling plate disposed at the top and bottom ends of the battery cell; The outer shell is composed of several hexagonal shells arranged in a honeycomb pattern. Each battery cell is placed in a hexagonal shell, and phase change material is filled between the battery cell and the hexagonal shell. Ribs are provided at the midpoints of the six surfaces of the hexagonal shell. One end of the rib is in direct contact with the battery cell, and the other end extends toward the hexagonal shell, thereby dividing the phase change material into six equal parts. The first liquid cooling plate and the second liquid cooling plate are connected by a liquid cooling channel. The first liquid cooling plate is provided with a working fluid inlet and the second liquid cooling plate is provided with a working fluid outlet. The working fluid flows in from the working fluid inlet of the first liquid cooling plate, flows through the liquid cooling channel to the second liquid cooling plate at the lower end of the cell, and finally flows out from the working fluid outlet.

2. The liquid-cooled phase-change hybrid battery thermal management system according to claim 1, characterized in that, The liquid cooling channels are vertically distributed in the outer casing, parallel to the battery cell, and are located at the six vertices of the hexagonal casing.

3. The liquid-cooled phase-change hybrid battery thermal management system according to claim 1, characterized in that, The first and second liquid cooling plates are provided with a meandering structural channel inside, in which the working fluid diffuses. The inflow and outflow of the liquid cooling channel are set in the path of the meandering structural channel, and the meandering structural channel is connected to the working fluid inlet and the working fluid outlet, respectively.

4. The liquid-cooled phase-change hybrid battery thermal management system according to claim 3, characterized in that, The meandering structure channel bends to form a meandering S-shaped structure, allowing the working fluid to flow through the top or bottom of each cell.

5. The liquid-cooled phase-change hybrid battery thermal management system according to claim 1, characterized in that, The outer casing is made of a material with high thermal conductivity, specifically aluminum or copper.

6. The liquid-cooled phase-change hybrid battery thermal management system according to claim 1, characterized in that, The phase change material specifically includes metal foam, porous polymer, carbon-based three-dimensional porous material, and porous ceramic material.

7. The liquid-cooled phase-change hybrid battery thermal management system according to claim 1, characterized in that, When dissipating heat at high temperatures, the cooling medium in the liquid cooling channel is liquid water, ethylene glycol, and gallium-based alloy liquid metal; when heating at low temperatures, the medium is boiling water.

8. A method for implementing the battery thermal management system according to any one of claims 1 to 7, characterized in that, include: When the battery cell operates in a high-temperature environment, it generates a large amount of heat during charging and discharging, causing the battery pack temperature to rise continuously. Part of the heat generated by the cell is transferred to the phase change material (PCM) through heat conduction, raising the PCM's temperature. Another part exchanges heat with the first and second liquid cooling plates, achieving further cooling. Meanwhile, the heat from the PCM is partially exchanged through direct contact with the first and second liquid cooling plates, and partially dissipated through the outer shell and fins, achieving secondary heat dissipation and enhancing overall cooling. Furthermore, a cooling medium is added to the working fluid inlet. After entering the first liquid cooling plate, the cooling medium flows rapidly through a meandering channel, then through vertically distributed liquid cooling channels to the second liquid cooling plate. It then flows through a meandering pipe within the second liquid cooling plate and finally exits the system from the working fluid outlet. A portion of the heat from the outer shell is carried away by the liquid cooling channels, while the remaining portion diffuses into the air. In a low-temperature environment, the heating medium is introduced into the first liquid cooling plate and flows rapidly in the meandering structural channel of the first liquid cooling plate. Then it flows from the liquid cooling channel to the second liquid cooling plate, and then flows in the meandering structural pipe in the second liquid cooling plate. Finally, it flows out of the system from the working medium outlet, thus achieving low-temperature heating.

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