Zinc-bromine flow battery electrolyte and zinc-bromine flow battery

Abstract

The present invention relates to the technical field of liquid flow batteries, and in particular to a zinc-bromine liquid flow battery electrolyte and a zinc-bromine liquid flow battery, wherein the zinc-bromine liquid flow battery electrolyte is used for a positive electrode electrolyte or a negative electrode electrolyte, and the zinc-bromine liquid flow battery electrolyte contains zinc bromide with a final concentration of 0.6-3 M and potassium chloride with a final concentration of 1-2 M, and also includes a complexing agent and an anti-dendrite agent, wherein the complexing agent is a pyrrolidine complexing agent or a pyridine complexing agent, and the anti-dendrite agent is a chloride anti-dendrite agent or a bromide anti-dendrite agent. The present invention adds a complexing agent and an anti-dendrite agent as auxiliary additives to the formula components of the positive electrode electrolyte and the negative electrode electrolyte of the zinc-bromine liquid flow battery, and combines the specific proportion range of each component of the formula, so that when the electrolyte is applied to the battery, the battery has better current efficiency and energy efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid flow batteries, and in particular to a zinc-bromine liquid flow battery electrolyte and a zinc-bromine liquid flow battery. Background Art

[0002] How to utilize and develop renewable resources has become a hot topic and research direction. Among them, liquid flow battery is a new technology suitable for large-scale energy storage. It achieves energy and power decoupling by separately adjusting the battery reactor and the electrolyte storage tank. Therefore, the energy storage system design is more flexible and the maintenance cost is lower. It has important application value in many scenarios such as wind / photovoltaic peak regulation and grid connection.

[0003] At present, the main flow batteries are zinc-bromine flow batteries and all-vanadium flow batteries. Among them, the cost of zinc-bromine flow batteries is only about 1 / 5 of that of all-vanadium flow batteries. With the continuous development of technology and related industries, the cost of zinc-bromine flow batteries is now close to that of lead-acid batteries. In theory, its cost can be even lower in the future. Compared with lithium batteries, the cost of zinc-bromine flow batteries is only about 1 / 5 of that of lithium batteries. In addition, in terms of energy density, the energy density of zinc-bromine flow batteries can reach 430Wh / kg. In terms of safety, zinc-bromine flow batteries have high performance stability and risk resistance. In terms of charging time and service life, zinc-bromine flow batteries have high charging efficiency, which makes their charging time short. At the same time, in fast charging mode, the damage to the battery is small. When discharging, it can be 100% deeply discharged, no self-discharge, ultra-high power, instantaneous charging, and almost no requirements for the working environment. Other advantages, so zinc-bromine flow batteries have a high cost-effectiveness, and further in-depth research on them to explore the improvement of the life, stability, energy density and other performance of zinc-bromine flow batteries has positive practical significance. Summary of the invention

[0004] One of the purposes of the present invention is to provide a zinc-bromine liquid flow battery electrolyte, which, after being applied to the battery, can make the zinc-bromine liquid flow battery have better comprehensive performance.

[0005] A second object of the present invention is to provide a zinc-bromine flow battery with better overall performance.

[0006] In order to achieve one of the above technical purposes, the technical solution adopted by the present invention is: a zinc-bromine liquid flow battery electrolyte, used as a positive electrode electrolyte or a negative electrode electrolyte, the zinc-bromine liquid flow battery electrolyte contains zinc bromide with a final concentration of 0.6-3 M and potassium chloride with a final concentration of 1-2 M, and also includes a complexing agent and an anti-dendrite agent, the complexing agent is a pyrrolidine complexing agent or a pyridine complexing agent, and the anti-dendrite agent is a chloride anti-dendrite agent or a bromide anti-dendrite agent Preferably, the final concentration of the complexing agent in the zinc-bromine flow battery electrolyte described in this embodiment is 0.1-0.7 M.

[0007] Preferably, the pyrrolidine complexing agent described in this embodiment is at least one of 1-butyl-1-methylpyrrolidine bromide and N-methyl-N-ethylpyrrolidine bromide; the final concentration of the pyrrolidine complexing agent is 0.2-0.7 M.

[0008] Preferably, the pyridine complexing agent in this embodiment is 1-ethyl-2-methylpyridinium bromide; the final concentration of the pyridine complexing agent is 0.1-0.5 M.

[0009] Preferably, the final concentration of the anti-dendrite agent in the zinc-bromine flow battery electrolyte described in this embodiment is 0.01-0.2 M.

[0010] Preferably, the chloride anti-dendrite agent described in this embodiment is at least one of stannous chloride and mercuric chloride, and the final concentration of the chloride anti-dendrite agent is 0.01-0.1 M.

[0011] Preferably, the bromide anti-dendrite agent described in this embodiment is one of tetramethylammonium bromide, tetraethylammonium bromide, tetrabutylammonium bromide, lead bromide, and selenium bromide, and the final concentration of the bromide anti-dendrite agent is 0.05-0.2 M.

[0012] Preferably, the present embodiment further comprises a perfluoroalkyl ethoxylate or a semifluoroacrolein-based polymer at a final concentration of 10-1000 ppm.

[0013] In order to achieve the second technical purpose above, the present invention also provides a zinc-bromine flow battery, which includes a positive electrode, a negative electrode, a separator and an electrolyte, wherein the electrolyte is the zinc-bromine flow battery electrolyte described above.

[0014] Preferably, the material of the positive electrode and / or negative electrode in this embodiment is graphite felt or carbon felt.

[0015] By adopting the above technical scheme, the present invention has the following beneficial effects compared with the prior art: by adding a chelating agent and an anti-dendritic agent as auxiliary additives to the formula components of the positive electrode electrolyte and the negative electrode electrolyte of the zinc-bromine flow battery, combined with the specific proportion range of each component of the formula, the electrolyte is applied to the battery, and the battery has better current efficiency and energy efficiency.

[0016] Compared with traditional electrolytes, the electrolyte of the present invention further improves the working stability of the battery and optimizes the formula composition while ensuring the battery performance. DETAILED DESCRIPTION

[0017] The present invention will be further described in detail below in conjunction with the embodiments. It is particularly noted that the following embodiments are only used to illustrate the present invention, but are not intended to limit the scope of the present invention. Similarly, the following embodiments are only partial embodiments of the present invention rather than all embodiments, and all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present invention.

[0018] Example 1 A zinc-bromine flow battery electrolyte comprises a positive electrode electrolyte and a negative electrode electrolyte, both of which are aqueous solutions, both of which contain zinc bromide with a final concentration of 0.6 M and potassium chloride with a final concentration of 1.0 M, and further comprises a chelating agent and an anti-dendritic agent.

[0019] Among them, the complexing agent described in this scheme is a pyrrolidine complexing agent; the anti-dendrite agent described in this scheme is a chloride anti-dendrite agent; specifically, the pyrrolidine complexing agent described in this scheme is 1-butyl-1-methylpyrrolidine bromide, and its final concentration is 0.2 M; the chloride anti-dendrite agent is stannous chloride, and its final concentration is 0.02 M.

[0020] Example 2 A zinc-bromine flow battery electrolyte comprises a positive electrode electrolyte and a negative electrode electrolyte, both of which are aqueous solutions, both of which contain zinc bromide with a final concentration of 1.2 M and potassium chloride with a final concentration of 1.1 M, and further comprises a chelating agent and an anti-dendritic agent.

[0021] Among them, the complexing agent described in this scheme is a pyrrolidine complexing agent; the anti-dendrite agent described in this scheme is a chloride anti-dendrite agent; specifically, the pyrrolidine complexing agent described in this scheme is 1-butyl-1-methylpyrrolidine bromide, and its final concentration is 0.3M; the chloride anti-dendrite agent is stannous chloride, and its final concentration is 0.04M.

[0022] Example 3 A zinc-bromine flow battery electrolyte comprises a positive electrode electrolyte and a negative electrode electrolyte, both of which are aqueous solutions, both of which contain zinc bromide with a final concentration of 1.4 M and potassium chloride with a final concentration of 1.2 M, and further comprises a chelating agent and an anti-dendritic agent.

[0023] Among them, the complexing agent described in this scheme is a pyrrolidine complexing agent; the anti-dendrite agent described in this scheme is a chloride anti-dendrite agent; specifically, the pyrrolidine complexing agent described in this scheme is 1-butyl-1-methylpyrrolidine bromide, and its final concentration is 0.4 M; the chloride anti-dendrite agent is stannous chloride, and its final concentration is 0.05 M.

[0024] Example 4 A zinc-bromine flow battery electrolyte comprises a positive electrode electrolyte and a negative electrode electrolyte, both of which are aqueous solutions, both of which contain zinc bromide with a final concentration of 1.6 M and potassium chloride with a final concentration of 1.3 M, and further comprises a chelating agent and an anti-dendritic agent.

[0025] Among them, the complexing agent described in this scheme is a pyrrolidine complexing agent; the anti-dendrite agent described in this scheme is a chloride anti-dendrite agent; specifically, the pyrrolidine complexing agent described in this scheme is 1-butyl-1-methylpyrrolidine bromide, and its final concentration is 0.45 M; the chloride anti-dendrite agent is stannous chloride, and its final concentration is 0.06 M.

[0026] Example 5 A zinc-bromine flow battery electrolyte comprises a positive electrode electrolyte and a negative electrode electrolyte, both of which are aqueous solutions, both of which contain zinc bromide with a final concentration of 1.8 M and potassium chloride with a final concentration of 1.4 M, and further comprises a chelating agent and an anti-dendritic agent.

[0027] Among them, the complexing agent described in this scheme is a pyridine complexing agent; the anti-dendrite agent described in this scheme is a chloride anti-dendrite agent; specifically, the pyridine complexing agent described in this scheme is 1-ethyl-2-methylpyridinium bromide; the final concentration of the pyridine complexing agent is 0.3 M; the chloride anti-dendrite agent described in this scheme is stannous chloride, and its final concentration is 0.065 M.

[0028] Example 6 A zinc-bromine flow battery electrolyte comprises a positive electrode electrolyte and a negative electrode electrolyte, both of which are aqueous solutions, both of which contain zinc bromide with a final concentration of 2.0 M and potassium chloride with a final concentration of 1.5 M, and further comprises a chelating agent and an anti-dendritic agent.

[0029] Among them, the complexing agent described in this scheme is a pyridine complexing agent; the anti-dendrite agent described in this scheme is a chloride anti-dendrite agent; specifically, the pyridine complexing agent described in this scheme is 1-ethyl-2-methylpyridinium bromide; the final concentration of the pyridine complexing agent is 0.35 M; the chloride anti-dendrite agent described in this scheme is stannous chloride, and its final concentration is 0.07 M.

[0030] Example 7 A zinc-bromine flow battery electrolyte comprises a positive electrode electrolyte and a negative electrode electrolyte, both of which are aqueous solutions, both of which contain zinc bromide with a final concentration of 2.5 M and potassium chloride with a final concentration of 1.8 M, and further comprises a chelating agent and an anti-dendritic agent.

[0031] Among them, the complexing agent described in this scheme is a pyridine complexing agent; the anti-dendrite agent described in this scheme is a chloride anti-dendrite agent.

[0032] Specifically, the pyridine complexing agent described in this scheme is 1-ethyl-2-methylpyridinium bromide; the final concentration of the pyridine complexing agent is 0.45 M; the chloride anti-dendritic agent described in this scheme is stannous chloride, and its final concentration is 0.09 M.

[0033] Example 8 A zinc-bromine flow battery electrolyte comprises a positive electrode electrolyte and a negative electrode electrolyte, both of which are aqueous solutions, both of which contain zinc bromide with a final concentration of 3.0 M and potassium chloride with a final concentration of 2.0 M, and further comprises a chelating agent and an anti-dendritic agent.

[0034] Among them, the complexing agent described in this scheme is a pyrrolidine complexing agent; the anti-dendrite agent described in this scheme is a bromide anti-dendrite agent; specifically, the pyrrolidine complexing agent described in this scheme is 1-butyl-1-methylpyrrolidine bromide, and its final concentration is 0.50 M; the bromide anti-dendrite agent described in this scheme is tetramethylammonium bromide, and its final concentration is 0.25 M.

[0035] Example 9 A zinc-bromine flow battery electrolyte comprises a positive electrode electrolyte and a negative electrode electrolyte, both of which are aqueous solutions, both of which contain zinc bromide with a final concentration of 2.5 M and potassium chloride with a final concentration of 1.8 M, and further comprises a chelating agent and an anti-dendritic agent.

[0036] Among them, the complexing agent described in this scheme is a pyrrolidine complexing agent; the anti-dendrite agent described in this scheme is a bromide anti-dendrite agent; specifically, the pyrrolidine complexing agent described in this scheme is 1-butyl-1-methylpyrrolidine bromide, and its final concentration is 0.65 M; the bromide anti-dendrite agent described in this scheme is tetramethylammonium bromide, and its final concentration is 0.15 M.

[0037] Example 10 A zinc-bromine flow battery electrolyte comprises a positive electrode electrolyte and a negative electrode electrolyte, both of which are aqueous solutions, both of which contain zinc bromide with a final concentration of 2.0 M and potassium chloride with a final concentration of 1.5 M, and further comprises a chelating agent and an anti-dendritic agent.

[0038] Among them, the complexing agent described in this scheme is a pyrrolidine complexing agent; the anti-dendrite agent described in this scheme is a bromide anti-dendrite agent; specifically, the pyrrolidine complexing agent described in this scheme is 1-butyl-1-methylpyrrolidine bromide, and its final concentration is 0.55 M; the bromide anti-dendrite agent described in this scheme is tetramethylammonium bromide, and its final concentration is 0.12 M.

[0039] Embodiment 11 A zinc-bromine flow battery electrolyte comprises a positive electrode electrolyte and a negative electrode electrolyte, both of which are aqueous solutions, both of which contain zinc bromide with a final concentration of 1.5 M and potassium chloride with a final concentration of 1.25 M, and further comprises a chelating agent and an anti-dendritic agent.

[0040] Among them, the complexing agent described in this scheme is a pyridine complexing agent; the anti-dendrite agent described in this scheme is a bromide anti-dendrite agent; specifically, the pyridine complexing agent described in this scheme is 1-ethyl-2-methylpyridinium bromide, and its final concentration is 0.45 M; the bromide anti-dendrite agent described in this scheme is lead bromide, and its final concentration is 0.09 M.

[0041] Example 12 A zinc-bromine flow battery electrolyte comprises a positive electrode electrolyte and a negative electrode electrolyte, both of which are aqueous solutions, both of which contain zinc bromide with a final concentration of 1.0 M and potassium chloride with a final concentration of 1.05 M, and further comprises a chelating agent and an anti-dendritic agent.

[0042] Among them, the complexing agent described in this scheme is a pyridine complexing agent; the anti-dendrite agent described in this scheme is a bromide anti-dendrite agent; specifically, the pyridine complexing agent described in this scheme is 1-ethyl-2-methylpyridinium bromide, and its final concentration is 0.25 M; the bromide anti-dendrite agent described in this scheme is lead bromide, and its final concentration is 0.07 M.

[0043] Embodiment 13 A zinc-bromine flow battery electrolyte comprises a positive electrode electrolyte and a negative electrode electrolyte, both of which are aqueous solutions, both of which contain zinc bromide with a final concentration of 0.6 M and potassium chloride with a final concentration of 1.0 M, and further comprises a chelating agent and an anti-dendritic agent.

[0044] Among them, the complexing agent described in this scheme is a pyridine complexing agent; the anti-dendrite agent described in this scheme is a bromide anti-dendrite agent; specifically, the pyridine complexing agent described in this scheme is 1-ethyl-2-methylpyridinium bromide, and its final concentration is 0.25 M; the bromide anti-dendrite agent described in this scheme is lead bromide, and its final concentration is 0.05 M.

[0045] Embodiment 14 A zinc-bromine flow battery electrolyte comprises a positive electrode electrolyte and a negative electrode electrolyte, both of which are aqueous solutions, both of which contain zinc bromide with a final concentration of 2.0 M and potassium chloride with a final concentration of 1.5 M, and further comprises a chelating agent and an anti-dendritic agent, and a semi-fluoroacrolein-based polymer with a final concentration of 1000 ppm.

[0046] Among them, the complexing agent described in this scheme is a pyridine complexing agent; the anti-dendrite agent described in this scheme is a chloride anti-dendrite agent; specifically, the pyridine complexing agent described in this scheme is 1-ethyl-2-methylpyridinium bromide; the final concentration of the pyridine complexing agent is 0.35 M; the chloride anti-dendrite agent described in this scheme is stannous chloride, and its final concentration is 0.07 M.

[0047] Embodiment 15 A zinc-bromine flow battery electrolyte comprises a positive electrode electrolyte and a negative electrode electrolyte, both of which are aqueous solutions, both of which contain zinc bromide with a final concentration of 2.0 M and potassium chloride with a final concentration of 1.5 M, and further comprises a chelating agent and an anti-dendritic agent, and perfluoroalkyl ethoxide with a final concentration of 10 ppm.

[0048] Among them, the complexing agent described in this scheme is a pyridine complexing agent; the anti-dendrite agent described in this scheme is a chloride anti-dendrite agent; specifically, the pyridine complexing agent described in this scheme is 1-ethyl-2-methylpyridinium bromide; the final concentration of the pyridine complexing agent is 0.35 M; the chloride anti-dendrite agent described in this scheme is stannous chloride, and its final concentration is 0.07 M.

[0049] Example 16 A zinc-bromine flow battery electrolyte comprises a positive electrode electrolyte and a negative electrode electrolyte, both of which are aqueous solutions, both of which contain zinc bromide with a final concentration of 2.0 M and potassium chloride with a final concentration of 1.5 M, and further comprises a chelating agent and an anti-dendritic agent, and a semi-fluoroacrolein-based polymer with a final concentration of 100 ppm.

[0050] Among them, the complexing agent described in this scheme is a pyridine complexing agent; the anti-dendrite agent described in this scheme is a chloride anti-dendrite agent; specifically, the pyridine complexing agent described in this scheme is 1-ethyl-2-methylpyridinium bromide; the final concentration of the pyridine complexing agent is 0.35 M; the chloride anti-dendrite agent described in this scheme is stannous chloride, and its final concentration is 0.07 M.

[0051] Comparative Example 1 A zinc-bromine flow battery electrolyte comprises a positive electrode electrolyte and a negative electrode electrolyte, both of which are aqueous solutions, both of which contain zinc bromide with a final concentration of 2.0 M and potassium chloride with a final concentration of 0.8 M, and further comprises a chelating agent and an anti-dendritic agent.

[0052] Among them, the complexing agent described in this scheme is a pyridine complexing agent; the anti-dendrite agent described in this scheme is a chloride anti-dendrite agent; specifically, the pyridine complexing agent described in this scheme is 1-ethyl-2-methylpyridinium bromide; the final concentration of the pyridine complexing agent is 0.35 M; the chloride anti-dendrite agent described in this scheme is stannous chloride, and its final concentration is 0.07 M.

[0053] Comparative Example 2 A zinc-bromine flow battery electrolyte comprises a positive electrode electrolyte and a negative electrode electrolyte, both of which are aqueous solutions, both of which contain zinc bromide with a final concentration of 2.0 M and potassium chloride with a final concentration of 0.8 M, and further comprises a chelating agent and an anti-dendritic agent.

[0054] Among them, the complexing agent described in this scheme is a pyridine complexing agent; the anti-dendrite agent described in this scheme is a bromide anti-dendrite agent; specifically, the pyridine complexing agent described in this scheme is 1-ethyl-2-methylpyridinium bromide, and its final concentration is 0.25 M; the bromide anti-dendrite agent described in this scheme is lead bromide, and its final concentration is 0.01 M.

[0055] Comparative Example 3 A zinc-bromine flow battery electrolyte comprises a positive electrode electrolyte and a negative electrode electrolyte, both of which are aqueous solutions, both of which contain zinc bromide with a final concentration of 2.0 M and potassium chloride with a final concentration of 0.8 M, and further comprises a chelating agent and an anti-dendritic agent.

[0056] Among them, the complexing agent described in this scheme is a pyrrolidine complexing agent; the anti-dendrite agent described in this scheme is a bromide anti-dendrite agent; specifically, the pyrrolidine complexing agent described in this scheme is 1-butyl-1-methylpyrrolidine bromide, and its final concentration is 0.15 M; the bromide anti-dendrite agent described in this scheme is tetramethylammonium bromide, and its final concentration is 0.01 M.

[0057] Comparison test In order to facilitate the application performance test of the electrolytes obtained in Examples 1 to 16 and Comparative Examples 1 to 3, this comparative test uses the electrolytes prepared in each example and comparative example in a zinc-bromine flow battery to explore the performance differences of each example and comparative example.

[0058] In the test, the zinc-bromine flow battery adopts the existing battery structure, and its current efficiency (or coulomb efficiency, CE) and energy efficiency (EE) are tested by injecting electrolyte; the assembled zinc-bromine flow battery includes a positive electrode, a negative electrode, a separator and an electrolyte. The materials of the positive and negative electrodes in this scheme are graphite felt, wherein the electrode surface area of ​​the positive and negative electrodes is 36 cm 2 The electrode thickness is 6 mm, the negative electrode thickness is 4 mm, and the diaphragm uses Celgard 2400 battery diaphragm; during the test, 40 mA / cm 2 The working parameters were charged and discharged, and the charging time was 90 min. The results are shown in Table 1 below: Table 1 Comparison of current efficiency and energy efficiency

[0059] It can be seen from Table 1 above that the formula ratio of Example 6 is better in comprehensive performance, and it has better current efficiency and energy efficiency. It can be inferred from the side that its formula composition is better. From the comprehensive examples and comparative examples, it can be learned that the complexing agent plays a more obvious role in the performance of the electrolyte. At the same time, the promotion effects of different complexing agents in the formula are different.

[0060] After the batteries assembled in the above-mentioned embodiments and comparative examples were used for 40 cycles, their battery plates were removed and observed, and it was found that a relatively obvious sponge-like zinc layer was found in Examples 1, 2, 3, 12, 13 and Comparative Examples 1, 2, 3, from which it can be learned that the concentration of the anti-dendrite agent can inhibit the generation rate of zinc dendrites to a certain extent.

[0061] It can be seen from Examples 14, 15 and 16 that when perfluoroalkyl ethoxylate or semifluoroacrylaldehyde polymer is added as a wetting agent, it can enhance the performance of the electrolyte.

[0062] The above descriptions are only some embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any equivalent device or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A zinc-bromine flow battery electrolyte, used as a positive electrode electrolyte or a negative electrode electrolyte, characterized in that: The zinc-bromine flow battery electrolyte contains zinc bromide with a final concentration of 0.6-3 M and potassium chloride with a final concentration of 1-2 M, and also includes a complexing agent and an anti-dendrite agent, wherein the complexing agent is a pyrrolidine complexing agent or a pyridine complexing agent, and the anti-dendrite agent is a chloride anti-dendrite agent or a bromide anti-dendrite agent.

2. The zinc-bromine flow battery electrolyte according to claim 1, characterized in that: In the zinc-bromine flow battery electrolyte, the final concentration of the complexing agent is 0.1-0.7 M.

3. The zinc-bromine flow battery electrolyte according to claim 2, characterized in that: The pyrrolidine complexing agent is at least one of 1-butyl-1-methylpyrrolidine bromide and N-methyl-N-ethylpyrrolidine bromide; the final concentration of the pyrrolidine complexing agent is 0.2-0.7 M.

4. The zinc-bromine flow battery electrolyte according to claim 2, characterized in that: The pyridine complexing agent is 1-ethyl-2-methylpyridinium bromide; the final concentration of the pyridine complexing agent is 0.1-0.5 M.

5. The zinc-bromine flow battery electrolyte according to any one of claims 1 to 4, characterized in that: In the zinc-bromine flow battery electrolyte, the final concentration of the anti-dendrite agent is 0.01-0.2 M.

6. The zinc-bromine flow battery electrolyte according to claim 5, characterized in that: The chloride anti-dendrite agent is at least one of stannous chloride and mercuric chloride, and the final concentration of the chloride anti-dendrite agent is 0.01-0.1 M.

7. The zinc-bromine flow battery electrolyte according to claim 5, characterized in that: The bromide anti-dendrite agent is at least one of tetramethylammonium bromide, tetraethylammonium bromide, tetrabutylammonium bromide, lead bromide, and selenium bromide, and the final concentration of the bromide anti-dendrite agent is 0.05-0.2 M.

8. The zinc-bromine flow battery electrolyte according to claim 1, characterized in that: It also includes a perfluoroalkyl ethoxylate or a semifluoroacryl polymer at a final concentration of 10-1000 ppm.

9. A zinc-bromine flow battery comprising a positive electrode, a negative electrode, a separator and an electrolyte, characterized in that: The electrolyte is the zinc-bromine flow battery electrolyte described in any one of claims 1-8.

10. The zinc-bromine flow battery according to claim 9, characterized in that: The material of the positive electrode and / or negative electrode is graphite felt or carbon felt.

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