Reconstruction of Electric Double Layer via Cationic Electrostatic Shielding and Anionic Preferential Adsorption Toward the Sustainable Zinc Metal Batteries

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.