Regulating Cu─Se Bonds by Molybdenum Orbital Hybridization to Facilitate Kinetics of Cu 2+ Transition for Advanced Aqueous Batteries

Abstract Electronic structure plays a critical role in regulating the conductivity and ion adsorption of electrode materials. In this work, it is demonstrated that Mo doping enhances the delocalization of 4d electrons and strengthens Mo–Se orbital hybridization in CuSe 2 , significantly improving electronic conductivity and facilitating charge transfer. Operando synchrotron experimental and theoretical calculation results jointly reveal that a tailored kinetic‐oriented CuSe 2 ‐Cu system constructed by coupling in situ 1T MoSe 2 ‐based electrochemical phase transfer and Cu x Se y stepwise conversion reactions. The trace amount of Mo doping facilitates Cu 2+ adsorption, reduce Cu 2+ diffusion barrier and triggers a redistribution of electron density from Cu─Se bonds to more stable Mo─Se bonds, contributing to enhanced interfacial ion diffusion and reaction activity. Consequently, the Mo‐CuSe 2 cathode achieved an initial charge/discharge capacity of 486.8/486.0 mAh g −1 at a current density of 15 A g −1 and maintained a capacity retention of 93% over 20 000 cycles. In addition, a practical Mo‐CuSe 2 ||Zn hybrid ion battery is constructed as a proof of concept, featuring an average working voltage of 1.17 V, and delivering specific energy and power of 614 Wh kg −1 and 4680 W kg −1 (based on the active material), respectively.