Solid-Electrolyte Interphase Chemistries Towards High-Performance Aqueous Zinc Metal Batteries.

Aqueous zinc metal batteries (AZMBs) are deemed a promising technology for electrochemical energy storage due to their high safety, low cost, and high energy density. However, AZMBs still suffer from severe side reactions, including Zn dendrite formation and intrinsic hydrogen evolution reaction. In contrast to the solid-electrolyte interphase (SEI) layer that stabilizes Li/Na/K metal anodes in organic electrolytes, it is difficult to form an SEI layer on the Zn surface because of the difficulty in decomposing the salt anions within the narrow electrochemical potential window of water. A team from the University of Adelaide reports a novel pure or hybrid electrolyte with H 2 O by using dimethyl methylphosphonate (DMMP) as solvent or co-solvent to construct a uniform and stable phosphate-based SEI layer (ZnP 2 O 6 and Zn 3 (PO 4 ) 2 ). As a result, high Coulombic efficiencies and improved capacity retentions are obtained.