Surface electron reconfiguration of ceric dioxide artificial interface layer by cationic doping for dendrite-free zinc anode

Aqueous zinc metal batteries (ZMBs) are regarded as strong contenders in secondary battery systems due to their high safety and abundant resources. However, the cycling performance of the Zn anode and the overall performance of the cells have often been hindered by the formation of Zn dendrites and the occurrence of parasitic side reactions. In this paper, a surface electron reconfiguration strategy is proposed to optimize the adsorption energy and migration energy of Zn²⁺ for a better Zn²⁺ deposition/stripping process by adjusting the electronic structure of ceric dioxide (CeO₂) artificial interface layer with copper atoms (Cu) doped. Both experimental results and theoretical calculations demonstrate that the Cu₂Ce₇O_x interface facilitates rapid transport of Zn²⁺ due to the optimized electronic structure and appropriate electron density, leading to a highly reversible and stable Zn anode. Consequently, the Cu₂Ce₇O_x@Zn symmetric cell exhibits an overpotential of only 24 mV after stably cycling for over 1600 h at a current density of 1 mA/cm² and a capacity of 1 mAh/cm². Additionally, the cycle life of Cu/Zn asymmetric cells exceeds 2500 h, with an average Coulombic efficiency of 99.9%. This paper provides a novel approach to the artificial interface layer strategy, offering new insights for improving the performance of ZMBs.