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

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 Zn²⁺ and H₂O molecules, effectively modulating the solvation shell structure. In situ optical microscopy shows the hybrid additive significantly suppresses HER and promotes Zn²⁺ 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.