Reconstruction of Electric Double Layer via Cationic Electrostatic Shielding and Anionic Preferential Adsorption...

Zinc metal is considered one of the most promising anodes for zinc-based batteries in energy storage systems. Nonetheless, zinc anodes are associated with some irreversible issues, Zn²⁺, which significantly restrict the endurance of aqueous zinc-ion batteries (AZIBs). This study adds a multifunctional electrolyte additive Ce(NO₃)₃ to a 3 m ZnSO₄ electrolyte to addressed these challenges. DFT simulations and experiments indicate a significant adsorption energy of NO₃ ^-on the zinc surface, implying that NO₃ ^- preferentially adsorbs within the inner Helmholtz layer and enhances the kinetics of zinc ion deposition, whereas the exposure to more (002) crystalline surfaces suppresses dendritic development. Ce³⁺ establishes a robust electrostatic shield in the inner Helmholtz layer, effectively homogenizing the electric field on the zinc anode surface, which significantly decreases the formation of sharp zinc dendrites during the plating/stripping process. A small amount of Ce is reduced to ultimately generate Ce-Zn alloy and CeO₂, which subsequently accelerates the migration of zinc ions and prevents hydrogen precipitation and side reactions. With these benefits, a Zn||Zn symmetric cell employing a Ce(NO₃)₃ additive electrolyte can maintain a cycle life of 4000 h with a low hysteresis voltage of 39 mV at a current density of 3 mA cm⁻².