Charging and discharging separation temperature control strategy for inhibiting dendritic crystal growth of zinc-based flow battery

Abstract

The invention discloses a charge-discharge separation temperature control strategy for inhibiting dendritic crystal growth of a zinc-based flow battery, and belongs to the field of zinc-based flow batteries. The method is designed for solving the problem of zinc dendrite growth caused by non-uniform zinc deposition on the negative electrode side of the zinc-based flow battery, and an electrolyte in a storage tank of the zinc-based flow battery is charged at 15-30 DEG C, so that the uniformity of zinc deposition is improved, and the zinc dendrite growth is inhibited; and the electrolyte in the zinc-based flow battery storage tank is discharged at 35-45 DEG C, so that the mass transfer rate of reaction ions in the battery is improved, and the energy efficiency of the battery is improved. The method is applied to the zinc-based flow battery, the battery efficiency can be remarkably improved, meanwhile, the zinc deposition morphology is improved, and the service life of the battery is prolonged.

Description

Technical Field

[0001] The present invention belongs to the field of zinc-based liquid flow batteries, and in particular relates to a charge-discharge separation temperature control strategy for inhibiting dendrite growth in zinc-based liquid flow batteries. Background Art

[0002] In modern society, with the rapid development of renewable energy, the importance of energy storage technology has become increasingly prominent. Renewable energy sources such as solar and wind power, due to their significant intermittent and volatile nature, pose significant challenges to energy transmission and utilization. Therefore, the importance of energy storage systems, as a key technology for balancing energy supply and demand and achieving sustainable energy utilization, is self-evident. Zinc-based flow batteries, as a highly promising energy storage solution, despite their low cost and high safety, are severely constrained by the problem of zinc dendrites, which directly impact the long-term stability and safety of the battery.

[0003] The formation of zinc dendrites is mainly due to the uneven deposition of zinc during the charge and discharge process. Studies have shown that the uniformity of zinc deposition is closely related to the ambient temperature: a low temperature environment is conducive to the uniform deposition of zinc, while zinc dendrites are more likely to present a sharp morphology under high temperature conditions. However, although low temperature can improve the uniformity of zinc deposition, it will lead to a decrease in the ion mass transfer rate inside the electrode, thereby exacerbating concentration polarization and affecting the energy efficiency of the battery. Therefore, precise temperature control of the charge and discharge process of zinc-based liquid flow batteries can not only optimize the uniformity of zinc deposition, but also effectively improve the energy efficiency of the battery, providing a feasible solution to the problem of zinc dendrites. Summary of the Invention

[0004] The present invention aims to overcome the shortcomings of the prior art by addressing the common zinc dendrite problem in zinc-based flow batteries and providing a separate charge-discharge temperature control strategy to inhibit dendrite growth in zinc-based flow batteries. This invention utilizes different temperature settings during the charge and discharge phases to improve zinc deposition uniformity during the charge phase and enhance battery energy efficiency during the discharge phase.

[0005] The specific technical solutions adopted in the present invention are as follows:

[0006] The present invention provides a charge-discharge separation temperature control strategy for suppressing dendrite growth in zinc-based flow batteries, as follows:

[0007] The electrolyte in the zinc-based flow battery storage tank is charged at 15-30°C and discharged at 35-45°C.

[0008] Preferably, the charging stage is as follows:

[0009] The electrolyte is cooled in a low-temperature water bath, and charging begins when the temperature drops to 15-30°C, and the water bath is kept at a constant temperature during the charging process.

[0010] Furthermore, the temperature of the low-temperature water bath is lower than 15°C.

[0011] Furthermore, the temperature of the constant temperature water bath is 15-30°C.

[0012] Furthermore, during the constant temperature water bath process, the electrolyte in the storage tank is mixed at a speed of 50 to 200 revolutions per minute.

[0013] Preferably, the discharge stage is specifically as follows:

[0014] The electrolyte is heated in a high-temperature water bath, and discharge begins when the temperature rises to 35-45°C, and the water bath is kept at a constant temperature during the discharge process.

[0015] Furthermore, the temperature of the high temperature water bath is higher than 45°C.

[0016] Furthermore, the constant temperature water bath temperature is 35-45°C.

[0017] Furthermore, during the constant temperature water bath process, the electrolyte in the storage tank is mixed at a speed of 50 to 200 revolutions per minute.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention adopts a temperature control strategy that separates the charge and discharge stages. The electrolyte temperature is controlled before charging or discharging, making full use of the characteristics of different charge and discharge stages. A lower temperature is used in the charge stage to achieve uniform zinc deposition, and a higher temperature is used in the discharge stage to reduce battery concentration polarization. This temperature control strategy can not only inhibit the growth of zinc dendrites, but also improve the energy efficiency of the battery. In addition, the electrolyte temperature control method adopted by the present invention can reduce the energy consumption required for temperature control, is simple to operate, and has good operability in practical applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of equipment connections when the temperature control strategy of the present invention is in operation;

[0021] Figure 2 The battery energy efficiency corresponding to different charging and discharging temperature combinations.

[0022] The reference numerals in the figure are: single cell 1, storage tank 2, peristaltic pump 3, electrochemical workstation or charge and discharge tester 4, constant temperature water bath 5. DETAILED DESCRIPTION

[0023] The present invention will be further described and illustrated below with reference to the accompanying drawings and specific embodiments. The technical features of each embodiment of the present invention may be combined accordingly without conflict.

[0024] The present invention provides a charge-discharge separation temperature control strategy for suppressing dendrite growth in zinc-based flow batteries. This temperature control strategy is designed to address the problem of zinc dendrite growth caused by uneven zinc deposition on the negative electrode side of zinc-based flow batteries. The specific details are as follows:

[0025] The electrolyte in the zinc-based flow battery tank is charged at 15-30°C to improve the uniformity of zinc deposition and inhibit the growth of zinc dendrites. The electrolyte in the zinc-based flow battery tank is discharged at 35-45°C to increase the mass transfer rate of reactant ions in the battery, thereby improving the battery energy efficiency.

[0026] The temperature control strategy of the present invention suppresses zinc dendrite growth and improves battery energy efficiency by regulating the electrolyte temperature in stages. This temperature control method has the advantages of low energy consumption and simple operation, making it suitable for practical application in zinc-based flow batteries.

[0027] As a preferred embodiment of the present invention, the charging stage is specifically as follows:

[0028] During the charging stage, the electrolyte is cooled in a low-temperature water bath. Charging begins when the temperature drops to 15-30°C, and the water bath is kept at a constant temperature during the charging process.

[0029] Specifically, during the charging process, the temperature of the low-temperature water bath should be below 15° C., and the temperature of the constant-temperature water bath should be 15-30° C. During the constant-temperature water bath process, a magnetic stirrer is used to mix the electrolyte in the storage tank at a speed of 50-200 revolutions per minute.

[0030] As a preferred embodiment of the present invention, the discharge stage is specifically as follows:

[0031] During the discharge stage, the electrolyte is heated in a high-temperature water bath. Discharge begins when the temperature rises to 35-45°C, and the water bath is kept at a constant temperature during the discharge process.

[0032] Specifically, during the discharge process, the temperature of the high-temperature water bath should be higher than 45° C., and the temperature of the constant-temperature water bath should be 35-45° C. During the constant-temperature water bath process, a magnetic stirrer is used to mix the electrolyte in the storage tank at a speed of 50-200 rpm.

[0033] The efficacy of the strategy of the present invention will be demonstrated below by comparing the examples with the comparative examples.

[0034] Example 1

[0035] This embodiment provides a charge-discharge separation temperature control strategy for suppressing dendrite growth in zinc-based flow batteries. The connection method of each component during operation is as follows: Figure 1 As shown, the storage tank 2 is placed in a constant temperature water bath 5, and the electrolyte is stirred evenly with a magnetic stirrer to uniformly maintain the temperature of the electrolyte in the storage tank 2. The uniform electrolyte is then introduced into the single cell 1 through a pipeline equipped with a peristaltic pump 3 for operation. The single cell 1 is also connected to an electrochemical workstation or charge-discharge tester 4 via a wire to monitor the discharge level in real time.

[0036] The temperature control strategy is as follows:

[0037] During the charging phase, the electrolyte in the storage tank is cooled by a low-temperature water bath. Charging begins when the temperature drops to 30°C, and the water bath is kept at a constant temperature of 30°C during the charging process.

[0038] During the discharge stage, the electrolyte in the storage tank is heated in a high-temperature water bath. Discharge begins when the temperature rises to 45°C, and the water bath is kept at a constant temperature of 45°C during the discharge process.

[0039] Example 2

[0040] This embodiment provides a charge-discharge separation temperature control strategy for suppressing dendrite growth in zinc-based flow batteries, as follows:

[0041] During the charging phase, the electrolyte in the storage tank is cooled by a low-temperature water bath. Charging begins when the temperature drops to 20°C, and the water bath is kept at a constant temperature of 20°C during the charging process.

[0042] During the discharge stage, the electrolyte in the storage tank is heated in a high-temperature water bath. Discharge begins when the temperature rises to 45°C, and the water bath is kept at a constant temperature of 45°C during the discharge process.

[0043] Comparative Example 1

[0044] This embodiment provides a temperature control strategy for charge and discharge separation, which is as follows:

[0045] During the charging phase, the electrolyte in the tank is temperature-regulated by a water bath. Charging begins when the temperature reaches 30°C, and the water bath is kept at a constant temperature of 30°C during the charging process.

[0046] During the discharge stage, the temperature of the electrolyte in the storage tank is adjusted by a water bath. Discharge begins when the temperature changes to 30°C, and the constant temperature of the water bath is maintained at 30°C during the discharge process.

[0047] Comparative Example 2

[0048] This embodiment provides a temperature control strategy for charge and discharge separation, which is as follows:

[0049] During the charging phase, the electrolyte in the tank is temperature-regulated by a water bath. Charging begins when the temperature reaches 45°C, and the water bath is kept at a constant temperature of 45°C during the charging process.

[0050] During the discharge stage, the temperature of the electrolyte in the storage tank is adjusted by a water bath. Discharge begins when the temperature changes to 45°C, and the constant temperature of the water bath is maintained at 45°C during the discharge process.

[0051] Here are the results:

[0052] Figure 2 The battery energy efficiency of the examples and comparative examples is shown. Comparative Example 1 has the lowest energy efficiency. Due to the simultaneous increase in charge and discharge temperatures, Comparative Example 2 also has a higher energy efficiency, but the energy consumption required for heating is relatively high. However, after adopting the temperature control strategy described in the present invention, the battery energy efficiency has been significantly improved. The energy efficiency of Examples 1 and 2 is close to that of Comparative Example 2, and heating only during the discharge process can reduce the heating energy consumption, confirming the effectiveness of the present invention. At the same time, although the charging temperature of Example 2 is lower, the overall efficiency is not much different from that of Example 1, and the lower charging temperature is more conducive to enhancing the uniformity of zinc deposition, demonstrating that the temperature range of Example 2 is more advantageous.

[0053] The present invention is aimed at the charge and discharge process of zinc-based liquid flow batteries. Before the battery enters the charge and discharge stage, the temperature of the electrolyte is precisely controlled to make full use of the characteristics of different stages for optimization. In the charging stage, a low temperature environment is used to promote the uniform deposition of zinc, while in the discharge stage, the concentration polarization phenomenon inside the battery is reduced by increasing the temperature. This staged temperature control strategy can not only effectively inhibit the growth of zinc dendrites, but also significantly improve the energy efficiency of the battery. In addition, the electrolyte temperature control method adopted in the method of the present invention has the characteristics of low energy consumption and simple operation. By optimizing the temperature control process, unnecessary energy consumption is reduced, and the operating process is simplified, making it highly feasible and practical in actual applications. This strategy provides an innovative solution for the performance optimization of zinc-based liquid flow batteries and has good engineering application prospects.

[0054] The embodiment described above is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Persons skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any technical solution obtained by equivalent substitution or equivalent transformation falls within the scope of protection of the present invention.

Claims

1. A charge-discharge separation temperature control strategy for inhibiting dendrite growth in zinc-based flow batteries, characterized in that: The electrolyte in the zinc-based flow battery storage tank is charged at 15-30°C and discharged at 35-45°C.

2. The charge-discharge separation temperature control strategy for suppressing dendrite growth in zinc-based flow batteries according to claim 1, characterized in that: The charging stage is as follows: The electrolyte is cooled in a low-temperature water bath, and charging begins when the temperature drops to 15-30°C, and the water bath is kept at a constant temperature during the charging process.

3. The charge-discharge separation temperature control strategy for suppressing dendrite growth in zinc-based flow batteries according to claim 2, characterized in that: The temperature of the low-temperature water bath is lower than 15°C.

4. The charge-discharge separation temperature control strategy for suppressing dendrite growth in zinc-based flow batteries according to claim 2, characterized in that: The temperature of the constant temperature water bath is 15-30°C.

5. The charge-discharge separation temperature control strategy for suppressing dendrite growth in zinc-based flow batteries according to claim 2, characterized in that: During the constant temperature water bath process, the electrolyte in the storage tank is mixed at a speed of 50 to 200 revolutions per minute.

6. The charge-discharge separation temperature control strategy for suppressing dendrite growth in zinc-based flow batteries according to claim 1, characterized in that: The discharge stage is specifically as follows: The electrolyte is heated in a high-temperature water bath, and discharge begins when the temperature rises to 35-45°C, and the water bath is kept at a constant temperature during the discharge process.

7. The charge-discharge separation temperature control strategy for suppressing dendrite growth in zinc-based flow batteries according to claim 6, characterized in that: The temperature of the high temperature water bath is higher than 45°C.

8. The charge-discharge separation temperature control strategy for suppressing dendrite growth in zinc-based flow batteries according to claim 6, characterized in that: The temperature of the constant temperature water bath is 35-45°C.

9. The charge-discharge separation temperature control strategy for suppressing dendrite growth in zinc-based flow batteries according to claim 6, characterized in that: During the constant temperature water bath process, the electrolyte in the storage tank is mixed at a speed of 50 to 200 revolutions per minute.

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