Growing attention to eco-friendly and sustainable energy sources makes people focus on the improvement of grid-scale energy storage systems. Lithium ion batteries have demerits for these applications due to the use of flammable non-aqueous electrolytes. With this regard, aqueous electrolytes have been actively investigated because of its safe property, fast charge/discharge rate capability, easy preparation process, non-toxicity, and eco-friendliness. Among many candidates for aqueous battery system, zinc ion has attracted considerable interests. Zinc has advantages of abundance, low redox potential, and high volumetric capacity. However, when used in alkaline electrolytes, several problems such as dendritic growth, formation of irreversible intermediates and capacity fade hamper its practical use. Even though mild acidic electrolytes were used to suppress dendritic growth, the corrosion of zinc anode and current collectors still depressed the cycling stability. Herein, we introduce recent studies on electrolytes for aqueous zinc ion battery revealing their principles, working mechanism and research goals.
2. 수계 액체 전해질(Aqueous liquid electrolyte)
3. 겔(gel) 전해질