A Universal Superhydrophobic‐Ionophilic Interfacial Strategy for Cycling Stable Aqueous Zinc Metal Electrodes under Low Current Density

Abstract

AbstractA key challenge to apply aqueous zinc‐metal batteries (AZMBs) as next‐generation energy storage devices is to eliminate the adverse reactions of hydrogen evolution, especially in low current. Here, superhydrophobic and ionophilic artificial solid electrolyte interface (HI‐SEI) on zinc anode is proposed and constructed by enhancing roughness and etching ion channels in universal polysiloxane polymer backbones. The HI‐SEI exhibits superhydrophobicity with high contact angle of 151.5° and ionophilicity with low activation energy of 23.97 kJ mol−1. Thus, the HI‐SEI isolates Zn metal and solvent water and promotes desolvation kinetics of Zn2+. Besides, the HI‐SEI alters the double electric layer structure to form a compact layer hardly any adsorbed solvent water, achieving a small nucleation overpotential of 5 mV and low self‐corrosion current density of 0.95 µA cm−2. Moreover, a symmetric cell with HI‐SEI@Zn anode has a cycle life of >1330 h at low current of 0.1 mA cm−2. And a full cell with HI‐SEI@Zn anode and NaV3O8‐1.5H2O cathode provides long cycle life and low capacity degradation (180 mAh g−1 after 1100 cycles). Hopefully, SEI designs based on such a strategy will be able to improve the low‐current cycling performance of the next‐generation AZMBs.