Hybrid Aqueous/Non-aqueous Electrolytes for Lithium-Ion and Zinc-Ion Batteries: A Mini-Review

In recent years, the development of aqueous lithium-ion batteries and aqueous zinc-ion batteries has received extensive attention thanks to the advantages of high safety, environmental friendliness, and easy assembly conditions. However, aqueous batteries are always restricted in terms of limited cycling stability and low energy density due to their intrinsically narrow electrochemical window, hydrogen evolution, and side reactions. These problems can be remarkably alleviated by hybridizing aqueous/non-aqueous electrolytes; however, few detailed discussions on relevant strategies have been reported. In this mini-review, we summarize the latest progress and contributions of various hybrid aqueous/non-aqueous electrolytes for rechargeable aqueous lithium-ion batteries and aqueous zinc-ion batteries. The current challenges and development directions are also discussed for hybrid electrolytes.