Temperature control device for end plate of monomer liquid flow battery and use method of temperature control device

Abstract

The invention discloses a temperature control device for single liquid flow battery end plates and a use method. The temperature control device comprises a pair of metal end plates arranged in parallel, a heating device, a temperature control system and the like. The end plate is made of high-thermal-conductivity aluminum alloy, at least three cylindrical holes are formed in the side direction of the end plate at equal intervals, the heating rods are inserted to heat the end plate, the temperature sensors are integrated at the tail ends of the heating rods, and the controller automatically adjusts the heating power according to data of the sensors. By directly heating the end plate of the battery monomer and utilizing the good heat-conducting property of metal, the temperature distribution of the whole battery monomer is more uniform, the working performance of the battery is optimized, the temperature fluctuation is reduced, the energy conversion efficiency is improved, the service life of the battery is prolonged, the safety and reliability of a system are enhanced, and the method is suitable for temperature control of the flow battery.

Description

Technical field

[0001] The present invention relates to the technical field of mass and heat transfer of liquid flow batteries, and in particular to a temperature control device for an end plate of a single liquid flow battery and a use method thereof. [Background Technology]

[0002] As the global energy mix shifts toward renewable energy, the use of clean energy sources such as solar and wind power is becoming increasingly widespread. However, the intermittent and fluctuating nature of these energy sources leads to unstable power supply. Energy storage technology is crucial to addressing this issue. As a highly efficient, large-scale energy storage technology, flow batteries, with their long lifespan, adjustable capacity, and high energy conversion efficiency, demonstrate significant potential for application in renewable energy storage and grid peak regulation.

[0003] Flow batteries operate by storing and releasing energy through electrochemical reactions between reactants in the electrolyte at the electrodes. During this process, temperature has a crucial impact on battery performance. When the temperature is too low, the viscosity of the electrolyte increases, ion migration slows, and the electrochemical reaction rate decreases, resulting in a decrease in battery output power and reduced energy conversion efficiency. When the temperature is too high, the aging of internal battery materials such as electrodes and diaphragms accelerates, potentially leading to thermal runaway and safety accidents. Furthermore, uneven temperatures can lead to inconsistent reaction rates within the battery, generating thermal stress and further impacting the battery's service life and performance stability.

[0004] Currently, the temperature control of flow batteries mainly adopts the traditional method of heating the liquid storage tank. This method heats the electrolyte in the liquid storage tank to increase its temperature, and then transports the heated electrolyte to the reaction area of ​​the battery cell through a pipe. However, this traditional temperature control method has many drawbacks: First, the problem of heat loss during pipeline transmission is significant. When the electrolyte flows in a long-distance pipeline, it will exchange heat with the surrounding environment. Especially when the ambient temperature fluctuates greatly or the pipeline insulation effect is poor, the heat loss is serious, resulting in the electrolyte temperature being lower than the set value when it reaches the reaction zone, and the temperature fluctuates greatly. For example, in the cold winter, the temperature of the electrolyte in the pipeline may drop significantly, making the temperature in the reaction zone uneven, affecting the normal operation of the battery.

[0005] Secondly, the temperature in the reaction area is uneven. Even if the electrolyte temperature in the storage tank is uniform, during the pipeline transportation process, the temperature distribution of the electrolyte when it reaches the reaction area will be uneven due to differences in the thermal conductivity of the pipeline material, uneven electrolyte flow rate, and the complexity of the pipeline layout. This uneven temperature distribution can cause some areas inside the battery to overheat and others to undercool. The material in the overheated area ages faster, and the reaction efficiency in the undercooled area is low, thereby reducing the overall performance and life of the battery.

[0006] Furthermore, traditional temperature control methods have a significant hysteresis effect. When the battery temperature needs to be adjusted, the electrolyte in the storage tank must first be heated and then transported to the reaction zone through pipes. This process takes a long time, especially in large-scale batteries and long pipes. The temperature adjustment response speed is very slow. When the external ambient temperature changes suddenly or the battery load fluctuates violently, the traditional temperature control system cannot adjust the temperature of the reaction zone in time, resulting in poor battery performance.

[0007] Furthermore, traditional temperature control systems require complex piping, pumping systems, and insulation, which increases system complexity and cost, while also making maintenance more difficult. Piping and pumping systems are prone to blockages and leaks, requiring regular maintenance and replacement, increasing operating costs.

[0008] To address the challenges of traditional flow battery temperature control, researchers have been searching for more effective temperature control methods. Currently, some research has attempted to incorporate heating elements within battery cells. However, these methods often suffer from uneven heating, complex installation, and significant impact on battery structure, and have not yet been widely adopted.

[0009] Therefore, developing a flow battery temperature control device that can directly control the temperature of battery cells, avoid pipeline heat loss and hysteresis effects, achieve uniform temperature distribution, and at the same time simplify the system structure and reduce maintenance costs has important practical significance and application value.

[0010] The disclosure of the above background technology content is only used to assist in understanding the inventive concept and technical solution of the present invention. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above content has been disclosed on the filing date of this patent application, the above background technology should not be used to evaluate the novelty and creativity of this application. [Summary of the invention]

[0011] The purpose of the present invention is to propose a temperature control device for the end plate of a single liquid flow battery and a method for use. By directly heating the end plate of the battery cell and utilizing the good thermal conductivity of metal, the temperature distribution of the entire battery cell is made more uniform, thereby solving the technical problems existing in the above-mentioned prior art and achieving the purpose of optimizing the working performance of the battery, reducing temperature fluctuations, improving energy conversion efficiency, and extending the service life of the battery.

[0012] To this end, the present invention adopts the following technical solutions:

[0013] A temperature control device for end plates of a liquid flow battery cell comprises: a pair of metal end plates arranged in parallel on both sides of the battery cell, used to seal the reaction area of ​​the battery cell and conduct heat, and made of a high thermal conductivity metal material; a heating device comprising at least three heating rods, wherein the end plates are laterally provided with cylindrical holes adapted to the heating rods, the heating rods being inserted into the holes and in close contact with the end plates; a temperature control system comprising a temperature sensor integrated into the tail end of the heating rod and a controller electrically connected to the temperature sensor, wherein the controller is used to adjust the power of the heating rod according to the temperature sensor data.

[0014] Preferably, the end plate is made of a high thermal conductivity metal material - 6061 aluminum alloy, with dimensions of 150±5×150±5×10±5 mm.

[0015] Preferably, the cylindrical holes are evenly spaced on the short side of the end plate, the diameter of the holes is 8±2 mm, the depth is 140±5 mm, and the positions of the holes are 45±5 mm, 90±5 mm, and 135±5 mm on the short side of the end plate, respectively.

[0016] Preferably, the heating rod is cylindrical with a diameter of 6±2 mm and a length of 140±5 mm, and is made of a high thermal conductivity material.

[0017] Preferably, the operating range of the temperature sensor is 10.0°C-50.0°C, and is used to monitor the end plate temperature in real time and feed back to the controller.

[0018] Preferably, the controller is a digital thermostat, which can automatically adjust the power output of the heating rod according to changes in ambient temperature and battery load.

[0019] Preferably, the contact area between the end plate surface and the heating rod is surface treated to improve heat conduction efficiency.

[0020] Preferably, the temperature control system further comprises an alarm module, which sends out an alarm signal and automatically cuts off the power to stop heating when the temperature of the end plate exceeds a set range.

[0021] A method for using a flow battery cell end plate temperature control device comprises the following steps:

[0022] (1) Temperature sensor calibration: Calibrate the temperature sensor using a standard temperature source to ensure that it accurately reflects the real-time temperature of the end plate surface;

[0023] (2) Heating power adjustment: The power of the heating rod is adjusted by the digital thermostat. The temperature control system automatically adjusts the power output of the heating rod according to the temperature data fed back by the sensor;

[0024] (3) Heating response: After the system is started, gradually adjust the heating power and observe the changes in the end plate temperature; the device is successfully started when the end plate temperature of the battery cell remains stable.

[0025] Preferably, the initial heating adjustment in step (2) is set to control the end plate temperature at 25.0°C.

[0026] The technical principle of the device described in the present invention is as follows:

[0027] In traditional solutions, heat must be transferred indirectly to the reaction zone through the flow of electrolyte, resulting in a long path and high thermal resistance. This invention, based on the excellent thermal conductivity of metal materials and the high efficiency of direct heating, designs a flow battery cell end plate temperature control device.

[0028] As a crucial component of the battery cell, the end plate is made of highly conductive 6061 aluminum alloy, offering excellent thermal conductivity. When a heating rod is inserted into the end plate's hole and powered, heat is rapidly transferred to the end plate through the contact interface between the heating rod and the end plate. Leveraging the metal's thermal conductivity, the heat rapidly diffuses within the end plate, creating a uniform temperature distribution.

[0029] After the temperature of the end plate rises, heat is transferred to the reaction zone of the battery cell, including the electrodes, diaphragm, and electrolyte, through thermal conduction, thereby raising the temperature of the entire battery cell. Compared with traditional methods of heating the electrolyte, the present invention directly heats the end plate, avoiding heat loss and hysteresis effects during the electrolyte transmission process through pipelines, allowing heat to be transferred to the reaction zone more directly and efficiently. At the same time, this method of directly heating the end plate makes the temperature of the battery cell more stable. Since there is no need for long-distance pipeline transmission, heat loss and interference from external factors are reduced. The end plate can continuously and stably provide heat to the reaction zone. Combined with a precise temperature control system, temperature fluctuations can be controlled within a very small range.

[0030] The temperature control system uses temperature sensors to monitor the end plate temperature in real time, forming a closed-loop control circuit. When the end plate temperature changes, the temperature sensor sends a signal back to the controller, which then adjusts the power of the heating rods according to a preset control strategy to achieve precise control of the end plate temperature. This real-time monitoring and dynamic adjustment ensures that the battery cells maintain a stable operating temperature under different operating conditions, improving battery performance and reliability.

[0031] Compared with the prior art, the present invention has the following technical advantages:

[0032] 1. Avoiding heat loss during pipeline transmission, achieving more uniform temperature distribution and improving temperature uniformity by 50%: Traditional flow battery temperature control methods heat the electrolyte in the storage tank and then transport it to the reaction zone through pipelines. During this process, the electrolyte exchanges heat with the pipeline and the external environment, resulting in significant heat loss and an overall thermal efficiency of only 50%-60%. Especially in long pipelines or when the ambient temperature fluctuates greatly, the electrolyte temperature has dropped significantly by the time it reaches the reaction zone, and the fluctuation is obvious, resulting in uneven temperature in the reaction zone.

[0033] The present invention directly heats the end plate, utilizing the high thermal conductivity of 6061 aluminum alloy. Heat does not need to be transmitted through long-distance pipelines, but can be quickly diffused directly within the end plate. Experiments have shown that the temperature difference on the end plate surface can be controlled within ±2.0°C, while the temperature difference with traditional methods is as high as ±4.0°C, and temperature uniformity is improved by 50%. This is because the end plate is the direct heating object, and the heating rod is in close contact with the end plate. The heat conduction path is short and efficient, avoiding heat loss in pipeline transmission, making the temperature of the reaction zone uniform and stable, ensuring that the electrochemical reaction proceeds under consistent temperature conditions, and improving the overall performance of the battery.

[0034] 2. Eliminate transmission lag effects, achieve rapid temperature response, and increase response speed by 5 times: In traditional methods, the electrolyte needs to be transported through pipelines, and it takes a long time from the liquid storage tank to the temperature change in the reaction zone. From 15.0°C to 25.0°C, the traditional method takes 15 minutes, while the present invention only takes 3 minutes, an efficiency increase of 80%. This is because in the traditional method, the electrolyte in the liquid storage tank has a large mass, and heating requires overcoming large thermal inertia, and there is a time delay in pipeline transmission, resulting in a lag in temperature regulation.

[0035] This invention directly heats the end plates, ensuring close contact between the heating rod and the end plates, resulting in a small heat capacity and a fast response. The temperature control system uses a sensor integrated into the end of the heating rod to monitor the temperature in real time. The controller can quickly adjust the power to promptly respond to changes in load or ambient temperature, avoiding temperature fluctuations caused by lags and ensuring that the battery operates at the optimal temperature. This is particularly suitable for scenarios with frequent load changes.

[0036] 3. Improve system energy efficiency, reduce energy loss, and increase heating speed by more than 80%: In traditional temperature control systems, there is energy loss in the pipelines, pumps, and insulation devices themselves, and the electrolyte temperature decays significantly in the pipeline, resulting in low overall energy efficiency. The present invention eliminates the complex pipeline heating and insulation system and directly heats the end plate, reducing pipeline heat loss and pump energy consumption. The high thermal conductivity of 6061 aluminum alloy enables rapid and uniform heat transfer, and the power of the heating rod can be precisely controlled, avoiding the need for continuous high-power heating to compensate for pipeline heat loss in traditional methods. Experiments show that under the same heating power (200W), it only takes 3 minutes for the end plate heating to raise the reaction zone temperature to 25.0°C, while the traditional method takes 15 minutes. This means that under the same heating task, the heating speed of the present invention is greatly improved, more than 80% higher than the traditional method. The increase in heating speed greatly improves energy utilization efficiency, because completing the heating task in a shorter time means that less energy is consumed per unit time, thereby reducing system operating costs. At the same time, since the energy loss of components such as pipes and pumps is reduced, the overall energy consumption of the system is also significantly reduced, further demonstrating the advantage of the present invention in energy saving.

[0037] 4. Improve temperature stability and extend battery life: The traditional method generates thermal stress inside the battery due to heat loss in the pipeline and uneven temperature in the reaction zone, which accelerates material aging. The present invention uniformly heats the end plate to stabilize the temperature of the battery cell within a fluctuation range of ±2.0°C, reducing the generation of thermal stress and effectively reducing electrode deformation caused by thermal stress. The uniform temperature distribution avoids local overheating or overcooling, and slows down the aging rate of materials such as electrodes and diaphragms. In the experiment, the battery using the traditional method of heating the electrolyte showed metal vanadium precipitation at the positive electrode, affecting the capacity retention rate, while the end plate heating system of the present invention did not have this phenomenon, indicating that it can effectively extend the battery life and improve the reliability of long-term operation.

[0038] 5. Simplify system design and reduce maintenance costs: Traditional temperature control systems rely on complex pipes, pumps, and insulation devices, which are prone to blockages, leaks, and other failures, requiring high maintenance frequency. This invention replaces traditional methods with end plate heating, reducing the number of pipes, pumps, and other components and simplifying the system structure. The end plate heating system has a simple structure, with heating rods inserted into the end plate holes for easy installation and no moving parts, reducing the probability of failure. At the same time, it reduces maintenance tasks such as pipe cleaning and pump repair, reducing maintenance costs and difficulty, and improving the reliability and maintainability of the system.

[0039] 6. Enhance system safety and avoid potential safety hazards: In traditional methods, local overheating may cause safety issues such as electrolyte decomposition, material failure, and even thermal runaway. The present invention avoids the generation of local high temperatures through uniform heating and precise temperature control, has high temperature stability, and reduces safety risks caused by abnormal temperatures. The temperature sensor monitors the end plate temperature in real time, and the controller can adjust the power or issue an alarm in time when the temperature is abnormal, further improving the safety of the system. Compared with traditional methods, the present invention reduces safety hazards from a design perspective and provides a strong guarantee for the safe operation of the flow battery.

[0040] 7. Adapt to complex working conditions and improve environmental adaptability: Under different ambient temperature and load conditions, traditional temperature control systems are difficult to adjust quickly, which affects battery performance. The end plate heating system of the present invention has a fast response speed and high temperature control accuracy, and can adjust the heating power in real time according to changes in ambient temperature and load. Whether in cold winter or hot summer, or when the battery load suddenly increases or decreases, the end plate temperature can be quickly stabilized within the optimal operating range, ensuring that battery performance is not affected by the external environment, thereby improving the adaptability and stability of the liquid flow battery under complex working conditions.

[0041] 8. Optimize electrochemical reaction conditions and improve energy conversion efficiency: A working environment with uniform and stable temperature provides good conditions for electrochemical reactions. In traditional methods, uneven temperature leads to inconsistent reaction rates, insufficient reaction in some areas, and low energy conversion efficiency. The present invention achieves uniform temperature in the reaction zone through end plate heating, stable ion migration rate, and more complete electrochemical reaction, thereby improving the energy conversion efficiency of the battery. Experiments have shown that under the same charge and discharge conditions, the energy conversion efficiency of batteries using the temperature control system of the present invention is more than 8% higher than that of traditional methods, with significant economic benefits.

Brief Description of the Drawings

[0042] Figure 1 This is a cross-sectional view of the assembly of the temperature control device for the end plate of a flow battery cell;

[0043] Figure 2 is a schematic diagram of the end plate structure;

[0044] Figure 3 This is the assembly diagram of the heating rod and the hole position;

[0045] The numbers in the figure are: end plate 1, battery cell 2, heating rod 3-1, heating rod 3-2, heating rod 3-3, hole 4-1, hole 4-2, hole 4-3, heating rod tail end 5-1, heating rod tail end 5-2, heating rod tail end 5-3, temperature sensor 6, controller 7. [Specific implementation method]

[0046] The foregoing has broadly described the features and technical advantages of the present invention so that the detailed description of the present invention can be better understood. Other features and advantages of the present invention will be described below. Those skilled in the art will understand that the disclosed concepts and specific embodiments can be easily used as a basis for modifying or designing other structures to accomplish the same purpose of the present invention. Those skilled in the art will also recognize that such equivalent constructions do not deviate from the spirit and scope of the present invention. The novel features, structures and methods of operation, and further objects and advantages that are considered to be characteristic of the present invention will be better understood from the following description in conjunction with the accompanying drawings. However, it should be deeply recognized that each feature provided is for description and illustration only and is not intended to limit the definition of the present invention. As used herein, "include", "comprise", "have", "contain", etc. are all open terms, that is, they mean including but not limited to.

[0047] A flow battery cell end plate temperature control device used in a specific embodiment includes: a pair of metal end plates 1, arranged in parallel on both sides of the battery cell, used to seal the reaction area of ​​the battery cell 2 and conduct heat, and made of high thermal conductivity metal material; a heating device, including three heating rods, namely heating rod 3-1, heating rod 3-2, and heating rod 3-3; the end plate 1 is laterally provided with cylindrical holes adapted to the heating rods, corresponding to holes 4-1, 4-2, and 4-3, the heating rods are inserted into the holes and in close contact with the end plate 1; a temperature control system, including temperature sensors 6 integrated into the tail ends 5-1, 5-2, and 5-3 of the heating rods and a controller 7 electrically connected to the temperature sensors 6, and the controller 7 is used to adjust the power of the heating rods according to the temperature sensor data. Figure 1 This is a cross-sectional view of the assembly of the temperature control device for the end plate of a flow battery cell; Figure 2 is a structural schematic diagram of the end plate 1; Figure 3 This is the assembly drawing of the heating rod and the hole position.

[0048] The end plate 1 is made of a high thermal conductivity metal material - 6061 aluminum alloy, and has a size of 150×150×10 mm.

[0049] The cylindrical holes are evenly spaced on the short side of the end plate 1 , with a diameter of 8 mm and a depth of 140 mm. The positions of holes 4 - 1 , 4 - 2 and 4 - 3 are respectively 45 mm, 90 mm and 135 mm from the short side of the end plate 1 .

[0050] The heating rod is cylindrical with a diameter of 6 mm and a length of 140 mm and is made of a high thermal conductivity material.

[0051] The operating range of the temperature sensor 6 is 10.0° C.-50.0° C., and is used to monitor the temperature of the end plate 1 in real time and feed back to the controller 7 .

[0052] The controller 7 is a digital temperature controller that can automatically adjust the power output of the heating rod according to changes in ambient temperature and battery load.

[0053] The surface of the end plate 1 is surface treated at the contact point with the heating rod to improve the heat conduction efficiency.

[0054] The temperature control system further comprises an alarm module, which sends out an alarm signal and automatically cuts off the power to stop heating when the temperature of the end plate 1 exceeds a set range.

[0055] A method for using a flow battery cell end plate temperature control device is used to debug and test the device, including the following steps:

[0056] (1) Calibration of temperature sensor 6: Calibrate the temperature sensor 6 using a standard temperature source to ensure that it accurately reflects the real-time temperature of the end plate 1 surface;

[0057] (2) Heating power adjustment: The power of the heating rod is adjusted by the digital thermostat. The temperature control system automatically adjusts the power output of the heating rod according to the temperature data fed back by the sensor. The initial heating adjustment is set to control the temperature of the end plate 1 at 25.0°C.

[0058] (3) Heating response: After the system is started, gradually adjust the heating power and observe the change in the temperature of the end plate 1; when the temperature of the end plate 1 of the battery cell 2 remains stable, the device is successfully started.

[0059] After the battery cell 2 is assembled and debugged, embodiments 1-5 are set up for operation tests.

[0060] Example 1

[0061] The steps to run the experiment are as follows:

[0062] (1) Place the battery cell 2 in a 15.0°C environment and adjust the operating temperature of the battery end plate 1 to 25.0°C through the temperature control system. The initial power of the heating rod is set to 200W and the current density is 50mA / cm 2 , the battery is charged and discharged for 100 cycles;

[0063] (2) During the experiment, the temperature of the end plate 1 of the battery cell 2 was monitored in real time by the temperature sensor 6. The time it took for the heating system to increase the temperature of the end plate 1 from 15.0°C to 25.0°C and maintain it within the stable range was recorded as 2 min 19 s;

[0064] (3) The uniformity of the surface temperature of the end plate 1 is detected through feedback from multiple temperature sensors 6. The temperature sensor data shows that the temperature distribution of the end plate 1 is relatively uniform, and the temperature difference is controlled within ±1.6°C.

[0065] (4) After a long period of operation test, the temperature of the end plate 1 of the battery cell 2 remains stable, and no abnormal temperature is too high or too low.

[0066] Example 2

[0067] The steps to run the experiment are as follows:

[0068] (1) Place the battery cell 2 in a 15.0°C environment and adjust the operating temperature of the battery end plate 1 to 25.0°C through the temperature control system. The initial power of the heating rod is set to 200W and the current density is 100mA / cm 2 , the battery is charged and discharged for 150 cycles;

[0069] (2) During the experiment, the temperature of the end plate 1 of the battery cell 2 was monitored in real time by the temperature sensor 6, and the time it took for the heating system to increase the temperature of the end plate 1 from 15.0°C to 25.0°C and maintain it within the stable range was recorded, which was 2 min 15 s;

[0070] (3) The uniformity of the surface temperature of the end plate 1 is detected through feedback from multiple temperature sensors 6. The temperature sensor data shows that the temperature distribution of the end plate 1 is relatively uniform, and the temperature difference is controlled within ±1.9°C.

[0071] (4) After a long period of operation test, the temperature of the end plate 1 of the battery cell 2 remains stable, and no abnormal temperature is too high or too low.

[0072] Example 3

[0073] The steps to run the experiment are as follows:

[0074] (1) Place the battery cell 2 in a 15.0°C environment and adjust the operating temperature of the battery end plate 1 to 25.0°C through the temperature control system. The initial power of the heating rod is set to 150W and the current density is 125mA / cm 2 , the battery is charged and discharged for 250 cycles;

[0075] (2) During the experiment, the temperature of the end plate 1 of the battery cell 2 was monitored in real time by the temperature sensor 6. The time it took for the heating system to increase the temperature of the end plate 1 from 15.0°C to 25.0°C and maintain it within the stable range was recorded as 2 minutes and 36 seconds;

[0076] (3) The uniformity of the surface temperature of the end plate 1 is detected through feedback from multiple temperature sensors 6. The temperature sensor data shows that the temperature distribution of the end plate 1 is relatively uniform, and the temperature difference is controlled within ±2.0°C.

[0077] (4) After a long period of operation test, the temperature of the end plate 1 of the battery cell 2 remains stable, and no abnormal temperature is too high or too low.

[0078] Example 4

[0079] The steps to run the experiment are as follows:

[0080] (1) Place the battery cell 2 in an environment of 15.0°C and adjust the operating temperature of the battery end plate 1 to 25.0°C through the temperature control system. The initial power of the heating rod is set to 250W and the current density is 75mA / cm 2 , the battery is charged and discharged for 300 cycles;

[0081] (2) During the experiment, the temperature of the end plate 1 of the battery cell 2 was monitored in real time by the temperature sensor 6, and the time it took for the heating system to increase the temperature of the end plate 1 from 15.0°C to 25.0°C and maintain it within the stable range was recorded, which was 2 min 10 s;

[0082] (3) The uniformity of the surface temperature of the end plate 1 is detected through feedback from multiple temperature sensors 6. The temperature sensor data shows that the temperature distribution of the end plate 1 is relatively uniform, and the temperature difference is controlled within ±2.0°C.

[0083] (4) After a long period of operation test, the temperature of the end plate 1 of the battery cell 2 remains stable, and no abnormal temperature is too high or too low.

[0084] Example 5

[0085] The steps to run the experiment are as follows:

[0086] (1) Place the battery cell 2 in a 15.0°C environment and adjust the operating temperature of the battery end plate 1 to 25.0°C through the temperature control system. The initial power of the heating rod is set to 200W and the current density is 100mA / cm 2 , the battery is charged and discharged for 200 cycles;

[0087] (2) During the experiment, the temperature of the end plate 1 of the battery cell 2 was monitored in real time by the temperature sensor 6, and the time it took for the heating system to increase the temperature of the end plate 1 from 15.0°C to 25.0°C and maintain it within the stable range was recorded, which was 2 min 15 s;

[0088] (3) The uniformity of the surface temperature of the end plate 1 is detected through feedback from multiple temperature sensors 6. The temperature sensor data shows that the temperature distribution of the end plate 1 is relatively uniform, and the temperature difference is controlled within ±2.0°C.

[0089] (4) After a long period of operation test, the temperature of the end plate 1 of the battery cell 2 remains stable, and no abnormal temperature is too high or too low.

[0090] In Examples 1-5, the end plate heating system can stably increase the end plate temperature from 15.0°C to 25.0°C, with an average heating time of 2 minutes and 19 seconds, a minimum of 2 minutes and 10 seconds, and a maximum of 2 minutes and 36 seconds, all within 3 minutes. This is an efficiency improvement of more than 80% compared to the traditional electrolyte heating method, which takes 15 minutes, meeting the rapid temperature control requirements of the flow battery. The temperature fluctuation range is always maintained within ±2.0°C. The temperature difference data of the five groups of examples are all ≤2.0°C, which is significantly better than the ±4.0°C of the traditional method. The stability is improved by 50%, ensuring that the battery operates in a high-precision temperature environment and avoiding the decrease in electrochemical reaction efficiency caused by temperature fluctuations.

[0091] Experiment to explore the performance of the temperature control device of the end plate of the flow battery:

[0092] By changing the number of cycles, current density and initial power of the heating rod in different embodiments, experiments were conducted to explore the impact of the performance of the liquid flow battery cell end plate temperature control device. The following experiments were designed and carried out using the operating experimental steps described in Example 1. The only difference was the number of cycles, current density and initial power of the heating rod; the remaining steps were the same as Example 1.

[0093] (1) Number of cycles

[0094] The number of cycles for Experiments 1-5 was set to 100, 150, 200, 250, and 300, respectively. Increasing the number of cycles simulated changes in battery performance over long-term use, observing the continued stability of the end plate temperature control device and the relationship between battery performance degradation over charge and discharge cycles and temperature control.

[0095] (2) Current density

[0096] For each cycle, the current density was set to 50 mA / cm 2 , 75mA / cm 2 , 100mA / cm 2 , 125mA / cm 2 Current density directly affects the battery's charge and discharge rate and power output. Different current densities will cause different amounts of heat to be generated inside the battery, thereby testing the temperature control capability of the end plate heating system under different heating conditions.

[0097] (3) Initial power of heating rod

[0098] In each example of a current density-cycle number combination, the initial heating rod power was set to 150 W, 200 W, and 250 W. By varying the initial heating rod power, the effects of different heating capacities on the end plate heating rate, temperature stability, and overall battery system energy consumption were investigated.

[0099] Take Experiment 1 as an example:

[0100] The steps to run the experiment are as follows:

[0101] (1) Place the battery cell 2 in an environment of 15.0°C and test it at a current density of 50 mA / cm 2 , 75mA / cm 2 , 100mA / cm 2 , 125mA / cm 2 Under the condition of , the operating temperature of the battery end plate 1 is adjusted to 25.0℃ by the temperature control system. The initial power of the heating rod is set to 150W, and the battery is charged and discharged for 100 cycles;

[0102] (2) During the experiment, the temperature of the end plate 1 of the battery cell 2 is monitored in real time by the temperature sensor 6, and the time it takes for the heating system to increase the temperature of the end plate 1 from 15.0°C to 25.0°C and maintain it within the stable range is recorded;

[0103] (3) Observe and record the feedback from multiple temperature sensors 6 after 100 charge and discharge cycles to detect the uniformity of the surface temperature of the end plate 1, whether the temperature of the end plate 1 of the battery cell 2 remains stable, and whether there are any abnormal conditions of excessively high or low temperatures.

[0104] According to the above steps, the experimental operations of Experimental Example 2 (150 cycles), Experimental Example 3 (200 cycles), Experimental Example 4 (250 cycles), and Experimental Example 5 (300 cycles) at different current densities were completed in sequence, and the corresponding data were recorded.

[0105] After completing each cycle number-current density combination, repeat the above experimental steps with varying heater initial power (150W, 200W, 250W), and record the temperature change, uniformity, and stability data at different heater initial power levels. The data for each experimental example is shown in the table below.

[0106] Table 1: Experimental data of Experimental Example 1

[0107]

[0108] Table 2: Experimental data of Experimental Example 2

[0109]

[0110] Table 3: Experimental data of Experimental Example 3

[0111]

[0112]

[0113] Table 4: Experimental data of Experimental Example 4

[0114]

[0115] Table 5: Experimental data of Experimental Example 5

[0116]

[0117]

[0118] The experiment revealed the influence of various variables on the performance of the flow battery temperature control device by setting multiple groups of working conditions such as the number of cycles, current density and initial power of the heating rod. The initial power of the heating rod is the dominant factor affecting the heating time. Under the same number of cycles and current density, the power increase significantly shortens the heating time: the heating time can be as short as 2:00 under the 250W working condition, which is about 30% shorter than the average under the 150W working condition, reflecting the role of high power in promoting rapid heat conduction. The current density indirectly affects the heating efficiency by changing the heat generation rate inside the battery. Under the same power, 125mA / cm 2 Compared to 50mA / cm 2 The heating time is shortened by about 5%-10%. For example, in Experiment 1, at 150W power, 125mA / cm 2 Compared to 50mA / cm 2 The speed is 9 seconds faster, reflecting the synergistic effect of battery self-heating on the temperature rise process under high current density. The increase in the number of cycles leads to aging of the internal battery materials and a slight increase in internal resistance, which is manifested as a slight decrease in temperature uniformity with the increase in the number of cycles. The temperature difference increases from ±1.5-2.0°C after 100 cycles to ±1.9-2.3°C after 300 cycles, but still remains within ±2.5°C, indicating that the end plate heating structure has the ability to stably control the heat distribution in long-term cycles. The closed-loop feedback mechanism of the temperature control system shows robustness under different variable combinations. The temperature stability of all operating conditions is marked as "yes", verifying the effectiveness of the digital thermostat in dynamically adjusting power according to load changes.

[0119] The present invention verifies the core performance advantages of the flow battery cell end plate temperature control device through multivariable experiments. Experimental examples 1-5 verify that the device is significantly superior to traditional electrolyte heating methods in key performance aspects such as temperature control accuracy, heating speed, uniformity, and stability:

[0120] 1. Temperature control effect: The end plate heating system can accurately control the end plate temperature, ensuring that the battery cells are always within a stable operating temperature range. The temperature control accuracy is high, and the temperature uniformity is smaller than the traditional method of heating the electrode liquid. The temperature fluctuation range of the battery cells using the end plate heating device is ±2.0°C, and the temperature fluctuation range of the battery cells using the electrolyte heating method is ±4.0°C. Compared with traditional temperature control methods, it has better stability, with stability increased by 50%.

[0121] 2. Heating speed: The design of the heating rod can increase the end plate temperature to the set value in a relatively short time, with a fast response speed. It only takes 3 minutes to increase the temperature from 15.0°C to 25.0°C. The traditional method of heating the electrolyte requires heating all the liquid in the liquid storage tank, which takes a long time. It takes 15 minutes to increase the temperature from 15.0°C to 25.0°C. Compared with the traditional method, the heating speed of the present invention is increased by 80%.

[0122] 3. Reliability and safety: Long-term trouble-free operation, perfect fault tolerance and alarm mechanism, uniform and stable temperature avoids the precipitation of positive electrode metal vanadium caused by local low temperature in traditional methods. No white deposits were observed on the positive electrode surface in the embodiment, and the battery life was extended.

[0123] 4. Engineering practicality: The structure is simple, and compared with traditional methods, it reduces pipes, pumps and other components, has low maintenance costs, and is suitable for the integrated design of flow battery cells of various specifications.

[0124] Experimental data show that the device has broken through the bottleneck of traditional flow battery temperature control technology through the synergy of its innovative end plate heating structure and intelligent temperature control system, providing reliable technical support for its large-scale application in renewable energy storage, grid peak regulation and other fields, and has significant technological advancement and practical application value.

[0125] Those skilled in the art will recognize that numerous variations to the above description are possible, and that the examples are intended only to describe one or more specific implementations.

[0126] Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and modifications can be made without departing from the spirit and scope of the present invention. In addition, the scope of application of the present invention is not limited to the specific embodiments of the processes, machines, manufactures, material compositions, modes, methods and steps described in the specification. From the disclosure of the present invention, those skilled in the art will readily utilize existing or later developed processes, machines, manufactures, material compositions, modes, methods or steps that essentially perform the same functions as the corresponding embodiments described herein or achieve the same results. Therefore, the appended claims are intended to include such processes, machines, manufactures, material compositions, modes, methods or steps.

Claims

1. A flow battery cell end plate temperature control device, characterized in that: include: A pair of metal end plates are arranged in parallel on both sides of the battery cell, used to seal the battery cell reaction area and conduct heat, and are made of high thermal conductivity metal material; the heating device includes at least three heating rods, and the end plates are provided with cylindrical holes adapted to the heating rods on the sides. The heating rods are inserted into the holes and are in close contact with the end plates; the temperature control system includes a temperature sensor integrated at the tail end of the heating rod and a controller electrically connected to the temperature sensor. The controller is used to adjust the power of the heating rod according to the temperature sensor data.

2. A flow battery cell end plate temperature control device according to claim 1, characterized in that: The end plate is made of a high thermal conductivity metal material - 6061 aluminum alloy, with dimensions of 150±5×150±5×10±5mm.

3. The temperature control device for a flow battery cell end plate according to claim 1, characterized in that: The cylindrical holes are evenly spaced on the short side of the end plate, with a diameter of 8±2 mm and a depth of 140±5 mm. The holes are located at 45±5 mm, 90±5 mm, and 135±5 mm of the short side of the end plate.

4. The temperature control device for a flow battery cell end plate according to claim 1, characterized in that: The heating rod is cylindrical with a diameter of 6±2 mm and a length of 140±5 mm and is made of a high thermal conductivity material.

5. The temperature control device for a flow battery cell end plate according to claim 1, characterized in that: The operating range of the temperature sensor is 10.0°C-50.0°C, and is used to monitor the end plate temperature in real time and feed back to the controller.

6. The temperature control device for a flow battery cell end plate according to claim 1, characterized in that: The controller is a digital thermostat that can automatically adjust the power output of the heating rod according to changes in ambient temperature and battery load.

7. The temperature control device for a flow battery cell end plate according to claim 1, characterized in that: The contact area between the end plate surface and the heating rod is surface treated to improve heat conduction efficiency.

8. The temperature control device for a flow battery cell end plate according to claim 1, characterized in that: The temperature control system also includes an alarm module, which sends an alarm signal and automatically cuts off the power to stop heating when the end plate temperature exceeds a set range.

9. A method for using the flow battery cell end plate temperature control device according to any one of claims 1 to 8, characterized in that: The following steps are involved: (1) Temperature sensor calibration: Calibrate the temperature sensor using a standard temperature source to ensure that it accurately reflects the real-time temperature of the end plate surface; (2) Heating power adjustment: The power of the heating rod is adjusted by the digital thermostat. The temperature control system automatically adjusts the power output of the heating rod according to the temperature data fed back by the sensor; (3) Heating response: After the system is started, gradually adjust the heating power and observe the changes in the end plate temperature; the device is successfully started when the end plate temperature of the battery cell remains stable.

10. The method for using the temperature control device for the end plate of a flow battery cell according to claim 9, characterized in that: The initial heating adjustment in step (2) is set to control the end plate temperature at 25.0°C.

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