Additive‐Regulated Favorable Electrical Double Layer Facilitates the Trade‐Off Between Kinetics and Reversibility for High‐Performance Aqueous Zn Ion Battery

Regulating the electric double layer (EDL) at the Zn/electrolyte interface by adding additives into aqueous electrolyte have received considerable attention because it is cost-effective to enhance the electrochemical performance of aqueous Zinc ion batteries (AZIBs). However, the balance between kinetics and reversibility during the Zn deposition/dissolution process remains challenging. In this work, the Diethoxydimethylsilane (DDS) additive with an appropriate concentration is introduced into 3 mol kg^-1 ZnSO₄ (3 m ZSO) electrolyte to regulate the favorable EDL on the Zn surface. Combing experimental characterizations and theoretical calculation, the favorable EDL is demonstrated that can prevent direct contact between water and Zn due to the preferential adsorption of DDS additives on the Zn surface to replace the water molecules in Helmholtz inner layer and promote the homogeneous Zn²⁺ flux to realize the uniform Zn deposition without the sacrifice of reaction kinetics, inhibiting the side reactions and Zn dendrites growth. Consequently, the Zn//Zn symmetrical cell, fabricated with an optimal quantity of DDS additives, exhibits an extraordinary cycling durability exceeding 8750 h at 0.5 mA cm^-2/0.5 mAh cm^-2 and 1600 h under demanding conditions of 5 mA cm^-2/5 mAh cm^-2. The Zn//Cu asymmetric cell shows remarkable Coulombic efficiency, reaching up to 99.8% over 5000 cycles.