CN-122025857-A - Aqueous zinc battery electrolyte, preparation method and application thereof

Abstract

The application discloses a water-based zinc battery electrolyte, a preparation method and application thereof, wherein the water-based zinc battery electrolyte consists of zinc salt, water and ionic liquid, and the mass ratio of the ionic liquid is not less than 50%. The aqueous zinc battery electrolyte provided by the application can be suitable for all common zinc salt systems in the market, can simply, conveniently and efficiently regulate the molar ratio of water to zinc salt in the electrolyte to be within 5 under the condition of not depending on high-solubility special zinc salt or a large amount of alkali metal salt, fundamentally solves the technical problems that the conventional zinc salt has poor solubility in water and is difficult to realize the low water/zinc salt molar ratio, and the technical problem of constructing a wide electrochemical stability window electrolyte core is solved, and greatly widens the raw material selection range of the high-salt concentration aqueous zinc battery electrolyte.

Inventors

• CHEN CHAOJI
• YU LE
• WANG SIJUN
• XU SHUYING

Assignees

• 武汉大学
• 湖北达雅生物科技股份有限公司

Dates

Publication Date

20260512

Application Date

20260305

Claims (10)

1. 1. The aqueous zinc battery electrolyte is characterized by comprising zinc salt, water and ionic liquid, wherein the mass ratio of the ionic liquid is not less than 50%.
2. 2. The aqueous zinc cell electrolyte of claim 1 wherein the molar ratio of water to zinc salt is less than or equal to 5.
3. 3. The aqueous zinc cell electrolyte of claim 1, wherein the water is present in an amount of no more than 10% by mass.
4. 4. The aqueous zinc cell electrolyte of claim 1, wherein the ionic liquid is an imidazole-based ionic liquid.
5. 5. The aqueous zinc cell electrolyte according to claim 4, wherein the ionic liquid is 1-ethyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide or 1-ethyl-3-methylimidazolium bis (fluorosulfonyl) imide.
6. 6. The aqueous zinc cell electrolyte of claim 1 wherein the zinc salt is any one or more of zinc sulfate, zinc trifluoromethane sulfonate, zinc bis (trifluoromethane sulfonyl imide), zinc acetate, and zinc chloride.
7. 7. The aqueous zinc cell electrolyte of claim 1, wherein the aqueous zinc cell electrolyte has an ionic conductivity of greater than or equal to 6 mS/cm and an electrochemical stability window of greater than or equal to 3.3V.
8. 8. A preparation method of a water-based zinc battery electrolyte is characterized in that zinc salt, water and ionic liquid are mutually dissolved to form a clear solution, namely the water-based zinc battery electrolyte.
9. 9. An aqueous zinc cell, comprising a positive electrode, a negative electrode and an electrolyte, wherein the electrolyte is the aqueous zinc cell electrolyte according to any one of claims 1 to 7 or the aqueous zinc cell electrolyte prepared by the preparation method according to claim 8.
10. 10. The aqueous zinc cell of claim 9, wherein the negative electrode is zinc metal or zinc alloy and the positive electrode is vanadium-based oxide.

Description

Aqueous zinc battery electrolyte, preparation method and application thereof Technical Field The application relates to the technical field of water-based batteries, in particular to a water-based zinc battery electrolyte, a preparation method and application thereof. Background The water system zinc ion battery has the advantages of high safety, abundant and widely distributed zinc resource reserves, low raw material and preparation cost and the like, becomes a technical route with great development potential in the field of large-scale electrochemical energy storage, has good application prospect in a plurality of energy storage scenes such as new energy storage power stations, power grid peak shaving, distributed energy storage and the like, and is an important support for solving the problem of renewable energy consumption and improving the running stability of a power grid. At present, the development of the water-based zinc ion battery to the high-voltage and high-energy density is promoted, the core requirement of the industrial large-scale application is realized, the electrochemical stability window of the electrolyte is widened, and the key technology break-through for achieving the development target is realized. The Water-in-Salt (WiS) electrolyte system is a main technical path for realizing a high-pressure Water system zinc battery at the present stage, can greatly inhibit the electrochemical activity of bulk Water by constructing an extremely high Salt concentration environment, and effectively reduce side reactions such as hydrogen evolution, oxygen evolution and the like in the charging and discharging process of the battery, thereby remarkably widening an electrochemical stability window of the electrolyte and fundamentally solving the technical problems of narrow stability window and severe side reaction under the high-pressure working condition of the traditional dilute Water electrolyte. Meanwhile, the salt-package water electrolyte system can be adapted to high-voltage anode materials, provides an important material basis for voltage improvement and energy density optimization of the water-based zinc battery, and is a core technical scheme for promoting performance upgrading of the water-based zinc battery. However, the conventional salt water-in-package strategy still faces a technical bottleneck which is difficult to break through in the practical industrial application of the water-based zinc battery, and severely limits the floor popularization of the technology. On one hand, the solubility of common zinc salts such as zinc sulfate, zinc acetate, zinc trifluoromethane sulfonate and the like in water is low, electrolyte is difficult to adjust to a core section of a water-in-salt mechanism with the molar ratio of water to zinc salt being less than or equal to 5, and the technical requirement of wide electrochemical stability window cannot be met, on the other hand, a small number of zinc salts with high water solubility such as zinc chloride have the problems of strong corrosiveness and poor oxidation stability, are easy to cause irreversible loss on components such as battery electrodes and diaphragms and greatly reduce the cycling stability of the battery, and in addition, in the prior art, in order to realize the water-in-salt effect with low water-salt ratio, the total salt concentration of the system is usually improved by a mode of introducing a large amount of alkali metal salt, the mode can lead to extremely low molar ratio of zinc salt in the electrolyte system, not only obviously reduce the transmission efficiency of zinc ions, but also introduce additional side reactions and seriously affect the core electrochemical performances such as the charge-discharge efficiency, capacity retention rate and the like of the zinc battery. In summary, how to develop an aqueous zinc battery electrolyte which can adapt to common zinc salts in the market, can realize ultra-low water/zinc salt molar ratio without introducing a large amount of alkali metal salt, has a wide electrochemical stability window and high ionic conductivity, and can effectively improve the circulation stability of a zinc metal negative electrode, becomes a technical problem to be solved in the art, and has important academic and industrial values for promoting the industrial application of the aqueous zinc battery in the field of large-scale energy storage. Disclosure of Invention The application aims to adapt to common zinc salt in the market, and can realize the water-based zinc battery electrolyte with ultralow water/zinc salt molar ratio without a large amount of alkali metal salt, and a preparation method and application thereof. In order to achieve the purpose, the technical scheme adopted by the application is that the aqueous zinc battery electrolyte consists of zinc salt, water and ionic liquid, wherein the mass ratio of the ionic liquid is not less than 50%. Preferably, the molar ratio of the water to the