Multi-functional protective material with atomically dispersed zincophilic site enabling long-life zinc anode

Abstract

Parasitic side reactions and the formation of zinc dendrites in aqueous solutions severely hinder the practical application of Zn metal anode. Carbon materials with high electrical conductivity, and mechanical robustness are promising protective materials for Zn anode, however, the zincophobic nature of carbon materials impede the cycling stability of zinc-ion batteries. Herein, a versatile design strategy is proposed by utilizing single atoms-doped carbon with atomically dispersed zincophilic sites as a multi-functional protective material for high-performance zinc anode. As exemplified by bismuth single atoms (Bi SAs), density functional calculations verify that the introduction of Bi SAs can enhance zincophilicity, promote robust adhesion to zinc foil, and effectively suppress hydrogen evolution. Guided by theoretical calculations, Bi single atoms-doped carbon nanobelts are synthesized and employed as a protective material to stabilize zinc anode. As expected, due to the atomic-level zincophilic Bi sites, hydrophobicity, and enhanced ionic conductivity , the Bi SAs@Zn anode demonstrates over 4200 h and 600 h of reversible cycling at 5 mA cm-2 and 20 mA cm-2, respectively, in symmetric cells. Meanwhile, the Bi SAs@Zn//MnO2 full cell achieves a stable lifespan of 1000 cycles at 1 A g−1, retaining 95.58% of the initial capacity.