Regulation of Zn2+ solvation shell by a novel N-methylacetamide based eutectic electrolyte toward high-performance zinc-ion batteries

Abstract

Aqueous Zn-ion batteries (AZIBs) have been regarded as promising alternatives to Li-ion batteries due to their advantages, such as low cost, high safety, and environmental friendliness. However, AZIBs face significant challenges in limited stability and lifetime owing to zinc dendrite growth and serious side reactions caused by water molecules in the aqueous electrolyte during cycling. To address these issues, a new eutectic electrolyte based on Zn(ClO4)2·6H2O-N-methylacetamide (ZN) is proposed in this work. Compared with aqueous electrolyte, the ZN eutectic electrolyte containing organic N-methylacetamide could regulate the solvated structure of Zn2+, effectively suppressing zinc dendrite growth and side reactions. As a result, the Zn//NH4V4O10 full cell with the eutectic ZN-1-3 electrolyte demonstrates significantly enhanced cycling stability after 1000 cycles at 1 A g−1. Therefore, this study not only presents a new eutectic electrolyte for zinc-ion batteries but also provides a deep understanding of the influence of Zn2+ solvation structure on the cycle stability, contributing to the exploration of novel electrolytes for high-performance AZIBs.