Multifunctional hybrid additive regulating solvation structure for dendrite-free and long-cycle-life zinc-ion batteries

Abstract

A high-performance hybrid electrolyte additive with an optimized concentration ratio was developed supported by theoretical and experimental evidence, demonstrating its ability to enhance Zn batteries performance through effective suppression of side reactions and regulation of Zn deposition. Aqueous zinc-ion batteries (AZIBs) have garnered extensive attention as the promising energy storage technology owing to their high safety, cost-effectiveness, and environmental friendliness. Nevertheless, their practical application is hindered by critical challenges, including Hydrogen evolution reactions (HER) and non-uniform Zn deposition, which compromise electrochemical performance and cycling stability. Herein, we propose a multifunctional hybrid electrolyte additive consisting of vanillin and Dimethyl sulfoxide, designed to weaken the interaction between Zn 2+ and H 2 O molecules, effectively modulating the solvation shell structure. In situ optical microscopy shows the hybrid additive significantly suppresses HER and promotes Zn 2+ deposition on the (002) plane, inhibiting dendritic growth. The Zn||Zn symmetric cells with hybrid additive exhibit exceptional cycling stability, achieving over 4000 h at 1.0 mA cm −2 /1.0 mA h cm −2 . The research on hybrid additives presents significant potential for exploration, offering a promising approach to the development of durable AZIBs.