Stabilized Zn Anode Based on SO42– Trapping Ability and High Hydrogen Evolution Barrier

Abstract

AbstractMetallic zinc as a promising anode material of aqueous zinc ion batteries is always impeded by some irreversible issues, such as dendrite growth, hydrogen evolution, and parasitic reaction, which severely affect the cycling stability and coulombic efficiency. Herein, the membrane of SO42‐ receptors is constructed on the Zn anode (denoted SO42‐ receptors as SR). The SR acts as a sulfate ion receptor to capture SO42‐, the resulting negatively charged coating can effectively disperses Zn2+ to promote uniform deposition and enhance Zn2+ mobility to stabilize high‐current cycling, while the repulsion of free SO42‐ coupled with high Gibbs free energy for hydrogen evolution reaction (ΔGH*) of SR and SR‐SO42‐ can effectively suppress the formation of parasitic (ZnSO4)·(Zn(OH)2)3∙xH2O. Benefiting from this versatility, Zn anode can achieve an average coulombic efficiency of over 99% and superior cycling performance (10 000 cycles for 10mA cm‐2 and 450 cycles for 5 mAh cm‐2). Meanwhile, Zn@SR/α‐MnO2 full battery can maintain 91.7% residual capacity after 900 cycles under 1.0 A g‐1.