All-vanadium redox flow battery thermal management system using phase change material
By introducing phase change materials and solar collectors into the all-vanadium redox flow battery system, and combining large and small circulation loops, the efficiency and lifespan problems caused by large temperature fluctuations were solved, and stable control of electrolyte temperature and improvement of battery performance were achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HEBEI CONSTR INVESTMENT AVIC SAIHAN GREEN ENERGY TECH DEV CO LTD
- Filing Date
- 2025-12-15
- Publication Date
- 2026-04-17
AI Technical Summary
In existing vanadium redox flow battery systems, temperature fluctuations are significant, leading to decreased charge and discharge efficiency and shortened battery life. In particular, it is difficult to maintain stable electrolyte temperature in regions with low ambient temperatures.
The electrolyte storage tank is equipped with an electrolyte chamber and a phase change chamber. The phase change chamber is filled with phase change material. Heat is collected by a solar collector and the phase change material is used to regulate the electrolyte temperature. Combined with large and small circulation loops, uniform temperature control is achieved.
It effectively controls electrolyte temperature fluctuations within ±2℃, improves charge and discharge efficiency by 15% to 20%, extends battery cycle life by 15% to 20%, and ensures electrolyte temperature uniformity and stability.
Smart Images
Figure CN121885672A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of vanadium redox flow battery technology, and more particularly to a thermal management system for vanadium redox flow batteries utilizing phase change materials. Background Technology
[0002] The normal operating temperature range of the electrolyte in a vanadium redox flow battery system is 20–40°C, which represents the optimal temperature range for the system's electrochemical performance and safety. Temperature fluctuations exceeding ±5°C can lead to a 3%–8% decrease in charge / discharge efficiency and a 1%–3% capacity decay per cycle. A stable temperature maintains ion conduction efficiency and catalytic activity, ensuring stable system output power. Existing traditional sensible heat control systems (such as cooling water) exhibit significant temperature fluctuations. Maintaining stable electrolyte temperature is particularly crucial for the efficient operation of vanadium redox flow batteries in regions with consistently low ambient temperatures. Summary of the Invention
[0003] The technical problem to be solved by the present invention is to provide a thermal management system for a vanadium redox flow battery that utilizes phase change materials, in order to address the above-mentioned technical deficiencies. The system employs an electrolyte storage tank with an electrolyte chamber and a phase change chamber, and the phase change chamber is filled with phase change materials, thereby solving the problem of large temperature fluctuations in existing traditional sensible heat control systems.
[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a thermal management system for a vanadium redox flow battery using phase change material, including an electrolyte storage tank, an electrolyte cavity and a phase change cavity provided in the electrolyte storage tank, the phase change cavity being filled with phase change material, and the phase change cavity including an inner cavity and an outer cavity that are interconnected.
[0005] To further optimize this technical solution, the electrolyte chamber is an annular cavity surrounded by an outer wall of polymer material, and the inner cavity is an inverted cone shape, located in the middle of the electrolyte chamber.
[0006] To further optimize this technical solution, heat exchange pipes are installed in the inner and outer cavities. The heat exchange pipes are connected to a heat storage tank through a circulation pipe. The heat storage tank is connected to a solar collector plate. The heat storage tank is used to store the heat collected by the solar collector plate and release the stored heat to the phase change cavity through the heat exchange pipes when needed.
[0007] This technical solution is further optimized. The heat exchange pipeline includes a heat absorption end and a heat release end. The heat absorption end is set inside the heat storage tank, and the heat release end is set inside the phase change cavity. A circulation pump is installed in the pipeline connecting the heat absorption end and the heat release end. The heat absorption end, the circulation pump and the heat release end form a large circulation loop. Heat exchange between the heat storage tank and the phase change cavity is realized through the large circulation loop.
[0008] To further optimize this technical solution, a connecting pipe is connected to the two pipelines connected to the heat release end. One end of the connecting pipe is connected to the heat exchange pipeline through a three-way valve. The three-way valve, the circulating pump, and the heat release end form a small circulation loop, which achieves a balanced heat distribution in the phase change cavity.
[0009] To further optimize this technical solution, an internal temperature sensor is installed in the inner cavity, an external temperature sensor is installed in the outer cavity, and a heat storage temperature sensor is installed in the heat storage tank. The internal temperature sensor, external temperature sensor, and heat storage temperature sensor are electrically connected to the signal input terminal of the controller, and the signal output terminal of the controller is electrically connected to the circulating pump.
[0010] To further optimize this technical solution, the phase change material can be any one of paraffin, fatty acid, or salt.
[0011] To further optimize this technical solution, multiple protrusions are provided on the outer wall of the electrolyte chamber, and multiple support parts are provided on the lower side of the bottom wall of the electrolyte chamber. The heat exchange pipeline passes between the protrusions and the support parts.
[0012] To further optimize this technical solution, the protrusion is a tilted spindle shape, the support is crescent-shaped, and multiple support parts are arranged radially at the bottom of the electrolyte chamber. The channel formed between the multiple support parts connects the inner and outer cavities.
[0013] Compared with existing technologies, this invention has the following advantages: 1. The phase change material maintains a basically constant temperature during the phase change process, effectively solving the problem of large temperature fluctuations in traditional sensible heat temperature control. Experimental data shows that the electrolyte temperature fluctuation range of the all-vanadium redox flow battery system using phase change material temperature control can be controlled within ±2℃, which is far superior to ±5℃ of the traditional method, significantly improving the battery's charge and discharge efficiency and cycle life. Under the same operating conditions, the capacity decay rate after 1000 cycles can be reduced by 15% to 20%; 2. Multiple protrusions increase the electrolyte chamber and phase change material. 3. The contact area is larger, resulting in better heat exchange and effectively maintaining a stable electrolyte temperature; 4. The phase change materials in the inner and outer cavities work together to regulate the temperature of the electrolyte chamber, with a larger contact area, which is especially effective in preventing overheating of the internal temperature of large-capacity electrolyte storage tanks; 5. The heat storage tank in the large circulation system stores the heat collected by the solar collectors and releases the stored heat to the phase change chamber through the heat exchange pipeline when needed. The phase change material in the phase change chamber heats up and then transfers the heat to the electrolyte chamber, avoiding direct heating of the electrolyte chamber by the heat exchange pipeline, resulting in more uniform heating of the electrolyte chamber. Attached Figure Description
[0014] Figure 1 This is a schematic diagram of a thermal management system for a vanadium redox flow battery utilizing phase change materials. Figure 2 This is a schematic diagram of the external structure of the electrolyte storage tank; Figure 3 This is a cross-sectional view of the electrolyte storage tank; Figure 4 This is a schematic diagram of the external structure on one side of the bottom of the electrolyte chamber; Figure 5 This is a schematic diagram of the external structure of one side of the top of the electrolyte chamber; Figure 6 This is a schematic diagram of the thermal storage tank section in a thermal management system for a vanadium redox flow battery utilizing phase change materials.
[0015] In the diagram: 1. Electrolyte storage tank; 10. Electrolyte chamber; 101. Protrusion; 102. Support; 11. Phase change chamber; 111. Outer chamber; 110. Inner chamber; 2. Heat exchange pipeline; 21. Heat absorption end; 22. Heat release end; 23. Circulation pump; 24. Connecting pipe; 25. Three-way valve; 3. Heat storage tank; 4. Solar collector panel; 41. Heat collection valve. Detailed Implementation
[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.
[0017] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains. Terms such as “up,” “down,” “left,” and “right” are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described object changes.
[0018] Combination Figures 1 to 4As shown, a thermal management system for a vanadium redox flow battery utilizing phase change materials includes an electrolyte storage tank 1. The electrolyte storage tank 1 contains an electrolyte chamber 10 and a phase change chamber 11. The electrolyte chamber 10 is an annular cavity formed by an outer wall of a polymer material, used to hold the positive or negative electrode electrolyte of the vanadium redox flow battery. The outer wall of the electrolyte chamber 10 has multiple protrusions 101, and the lower side of the bottom wall of the electrolyte chamber 10 has multiple support portions 102. The phase change chamber 11 is filled with a phase change material, which can be any one of paraffin wax, fatty acid, or salt. In use, when the electrolyte temperature in the electrolyte chamber 10 rises (such as during the charging process), the phase change material absorbs heat and undergoes a phase change (solid-to-liquid), which can directly reduce the electrolyte temperature. When the electrolyte temperature decreases (such as in a low-temperature environment or at the end of the discharge), the phase change material releases latent heat (liquid-to-solid). The multiple protrusions 101 increase the contact area between the electrolyte chamber 10 and the phase change material, resulting in better heat exchange and effectively maintaining a stable electrolyte temperature. The latent heat of the phase change material can be used to directly regulate the electrolyte temperature.
[0019] More specifically, in combination Figures 2 to 5 As shown, the phase change cavity 11 includes an inner cavity 110 and an outer cavity 111 that are interconnected. An external temperature sensor is installed inside the outer cavity 111. The inner cavity 110 is an inverted cone shape and is located at the rotation center of the electrolyte cavity 10. An internal temperature sensor is installed inside the inner cavity 110. To better display the full view of the interior of the outer cavity 111, in... Figure 4 and Figure 5 The outer wall of the outer cavity 111 has been removed, which allows for a better view of the arrangement of the protrusion 101 and the support 102. During use, the phase change materials in the inner cavity 110 and the outer cavity 111 work together to regulate the temperature of the electrolyte chamber 10. The inner cavity 110 is set in a conical shape so that the top of the inner cavity 110 can accommodate more phase change material, resulting in stronger heat absorption capacity and better temperature regulation capability. The connection between the inner cavity 110 and the outer cavity 111 enables the autonomous flow and heat transfer of the phase change material in the two cavities, making the heat distribution more uniform. In addition, the larger contact area between the protrusion 101 and the electrolyte chamber 10 can effectively prevent the internal temperature from overheating.
[0020] A heat exchange pipe 2 is connected to the inner cavity 110 and the outer cavity 111, passing between the protrusion 101 and the support 102. The heat exchange pipe 2 is connected to a heat storage tank 3 via a circulation pipe. A heat storage temperature sensor is installed inside the heat storage tank 3 to monitor its internal temperature. Figure 6 As shown, the heat storage tank 3 is connected to a solar collector plate 4, and a heat collection valve 41 is installed in the heat source output pipe of the solar collector plate 4.
[0021] Further integration Figure 1As shown, the heat exchange pipeline 2 includes a heat absorption end 21 and a heat release end 22. The heat absorption end 21 is located inside the heat storage tank 3, and the heat release end 22 is located inside the phase change cavity 11. A circulation pump 23 is installed in the pipeline connecting the heat absorption end 21 and the heat release end 22. The heat absorption end 21, the circulation pump 23, and the heat release end 22 in the heat exchange pipeline 2 form a large circulation loop. The internal temperature sensor, the external temperature sensor, and the heat storage temperature sensor (located in the middle of the inner wall of the heat storage tank 3) are electrically connected to the signal input terminal of the controller. The signal output terminal of the controller is electrically connected to the circulation pump 23. In use, when the internal temperature sensor and the external temperature sensor detect that the temperature of the phase change cavity 11 is too low to meet the normal operating temperature of the electrolyte chamber 10, the circulation pump 23 is started by the controller, and the large circulation loop is started to realize heat exchange between the heat storage tank 3 and the phase change cavity 11. In the large circulation, the heat storage tank 3 is used to store the heat collected by the solar collector 4, and release the stored heat to the phase change cavity 11 through the heat exchange pipeline 2 when needed. The phase change material in the phase change cavity 11 heats up and then transfers the heat to the electrolyte cavity 10. The electrolyte cavity 10 is heated more evenly, avoiding local overheating of the electrolyte caused by direct heat transfer.
[0022] Combination Figure 1 As shown, a connecting pipe 24 connects the two pipes connected to the heat dissipation end 22. One end of the connecting pipe 24 is connected to the heat exchange pipe 2 via a three-way valve 25. The three-way valve 25, the circulating pump 23, and the heat dissipation end 22 form a small circulation loop. Figures 3 to 5 As shown, part of the heat-dissipating end 22 is inserted into the middle of the inner cavity 110, and part is wrapped around the lower side of the outer cavity 111. During use, by switching the three-way valve 25, both ends of the connecting pipe 24 are fully connected to the heat exchange pipe 2. Simultaneously, a circulation loop is not formed on the left side of the three-way valve 25, preventing heat from flowing to the right. At this point, activating the circulation pump 23 enables local self-circulation of the heat-dissipating end 22 pipe, accelerating heat transfer between the inner cavity 110 and the outer cavity 111. This allows more phase change material in the phase change chamber 11 to better participate in the temperature regulation of the electrolyte storage tank 1, improving temperature regulation efficiency and the utilization rate of the phase change material. Achieving a balanced heat distribution within the phase change chamber 11 through a small circulation loop effectively improves the temperature regulation capability of the electrolyte storage tank 1.
[0023] The protrusion 101 is inclined and spindle-shaped, while the support 102 is crescent-shaped. Multiple support 102s are radially arranged at the bottom of the electrolyte chamber 10, and the channels formed between the multiple support 102s connect the inner chamber 110 and the outer chamber 111. During use, when a large temperature difference is detected between the inner chamber 110 and the outer chamber 111, a small circulation loop is activated to equalize the internal temperature of the electrolyte storage tank 1, ensuring stable system operation and extending the service life of the electrolyte.
[0024] Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
Claims
1. A thermal management system for a vanadium redox flow battery using phase change material, comprising an electrolyte tank (1), characterized in that: The electrolyte storage tank (1) is provided with an electrolyte chamber (10) and a phase change chamber (11). The phase change chamber (11) is filled with a phase change material and includes an inner cavity (110) and an outer cavity (111) that are interconnected.
2. The thermal management system for a vanadium redox flow battery utilizing phase change material of claim 1, wherein: The electrolyte chamber (10) is an annular cavity surrounded by an outer wall of polymer material, and the inner cavity (110) is an inverted cone shape, which is located in the middle of the electrolyte chamber (10).
3. The thermal management system for a vanadium redox flow battery utilizing phase change materials according to claim 1, characterized in that: Heat exchange pipes (2) are installed in the inner cavity (110) and the outer cavity (111). The heat exchange pipes (2) are connected to a heat storage tank (3) through a circulation pipe. The heat storage tank (3) is connected to a solar collector plate (4). The heat storage tank (3) is used to store the heat collected by the solar collector plate (4) and release the stored heat to the phase change cavity (11) through the heat exchange pipes (2) when needed.
4. A thermal management system for a vanadium redox flow battery utilizing phase change materials according to claim 3, characterized in that: The heat exchange pipeline (2) includes a heat absorption end (21) and a heat release end (22). The heat absorption end (21) is located inside the heat storage tank (3), and the heat release end (22) is located inside the phase change cavity (11). A circulation pump (23) is provided in the pipeline connecting the heat absorption end (21) and the heat release end (22). The heat absorption end (21), the circulation pump (23) and the heat release end (22) constitute a large circulation loop, and the heat exchange between the heat storage tank (3) and the phase change cavity (11) is realized through the large circulation loop.
5. A thermal management system for a vanadium redox flow battery utilizing phase change materials according to claim 4, characterized in that: A connecting pipe (24) is connected to one of the two pipes connected to the heat release end (22). One end of the connecting pipe (24) is connected to the heat exchange pipe (2) through a three-way valve (25). The three-way valve (25), the circulating pump (23) and the heat release end (22) form a small circulation loop. The heat distribution in the phase change cavity (11) is balanced through the small circulation loop.
6. A thermal management system for a vanadium redox flow battery utilizing phase change materials according to claim 5, characterized in that: An internal temperature sensor is provided in the inner cavity (110), an external temperature sensor is provided in the outer cavity (111), and a heat storage temperature sensor is provided in the heat storage tank (3). The internal temperature sensor, the external temperature sensor, and the heat storage temperature sensor are electrically connected to the signal input terminal of the controller, and the signal output terminal of the controller is electrically connected to the circulating pump (23).
7. A thermal management system for a vanadium redox flow battery utilizing phase change materials according to claim 1, characterized in that: The phase change material is any one of paraffin, fatty acid, or salt.
8. A thermal management system for a vanadium redox flow battery utilizing phase change materials according to claim 2, characterized in that: The outer wall of the electrolyte chamber (10) is provided with a plurality of protrusions (101), and the lower side of the bottom wall of the electrolyte chamber (10) is provided with a plurality of support parts (102). The heat exchange pipeline (2) passes between the protrusions (101) and the support parts (102).
9. A thermal management system for a vanadium redox flow battery utilizing phase change materials according to claim 8, characterized in that: The protrusion (101) is an inclined spindle shape, the support (102) is crescent-shaped, and a plurality of the support (102) are arranged radially at the bottom of the electrolyte cavity (10). The channel formed between the plurality of support (102) connects the inner cavity (110) and the outer cavity (111) to each other.