A Non-Alkaline Electrolyte for Electrically Rechargeable Zinc-Air Batteries with Long-Term Operation Stability in Ambient Air.

Electrically rechargeable zinc-air batteries attract extensive research interests due to their potentially high energy density and low cost but suffer from chemical instability and poor electrochemical reversibility caused by the corrosive nature of the conventional alkaline electrolyte. Here we demonstrate a non-alkaline zinc acetate electrolyte for electrically rechargeable zinc-air batteries with long-term operation stability (>600 hours) in ambient air without any special cell engineering. The unique battery chemistry with reversible formation/decomposition of zinc hydroxyacetate dihydrate is systematically revealed using diversified electrochemical and analytical techniques. Furthermore, the carbon-based air cathode is modified towards a hydrophilic surface to increase the energy efficiency. This work provides new insight on effective electrolyte design to achieve long-term operation zinc-air batteries.