Chalcogen-Doping Engineered Electronic Reconstruction of Cu₂O@Cu Cathode Toward High-Performance Cu-Zn Batteries

High-performance cathode materials are a key to promoting the development of aqueous zinc-based batteries (AZBs). In this work, we introduce two advanced chalcogen (Se, Te)-doped Cu₂O@Cu cathodes synthesized through a simple two-step hydrothermal method. Structural and electronic characterization combined with density functional theory (DFT) calculations demonstrate that doping with Se or Te in Cu₂O and Cu⁰ leads to a rearrangement of the electronic structure in Cu₂O@Cu. The effect significantly enhances the OH^- adsorption energy, charge transfer kinetics, activity, and stability of Cu₂O@Cu. Electrochemical results indicate that the optimal Se-Cu₂O@Cu and Te-Cu₂O@Cu electrodes achieve ultra-high specific capacities of 32.6 mAh cm^-2 (549.8 mAh g^-1) and 28.47 mAh cm^-2 (462.9 mAh g^-1), respectively, along with remarkable cycling stability (exceeding 1000 cycles), outperforming undoped Cu₂O@Cu (7.81 mAh cm^-2, 134.2 mAh g^-1, 150 cycles). When assembled into Cu//Zn batteries by coupling with a metallic zinc anode, the Se-Cu₂O@Cu//Zn and Te-Cu₂O@Cu//Zn batteries deliver high energy densities of 9.59 and 12.76 mWh cm^-2, respectively, which outperform most existing aqueous battery systems. This study offers fundamental insights into the role of Se (Te) doping in Cu₂O@Cu electrodes and proposes an effective strategy for designing high-performance copper-based cathodes for AZBs.