Ethylene Glycol as an Antifreeze Additive and Corrosion Inhibitor for Aqueous Zinc‐Ion Batteries

Abstract Aqueous zinc‐ion batteries are promising candidates for portable and large‐scale applications because of their intrinsically high safety, low cost and high theoretical energy density. However, existing aqueous zinc‐ion batteries usually suffer from zinc corrosion and poor performance at subzero temperatures. Herein, to address these problems, the electrolyte in aqueous zinc‐ion batteries (1 M ZnSO₄) is modified by adding suitable amounts of ethylene glycol. The addition of ethylene glycol improves the antifreezing ability of the aqueous electrolyte and increases the conductivity of electrolyte at low temperatures. Ethylene glycol serves two purposes, as an antifreeze additive to significantly enhance the capacity of batteries at low temperatures and as a corrosion inhibitor to suppress zinc corrosion and byproduct precipitation. This work offers a facile strategy to realize aqueous zinc‐ion batteries with good performance at low temperatures.