Salt-templated synthesis of carbon nanosheets decorated with high valence tungsten doped Co2P nanoparticles for efficient Zn-air battery

Abstract

An ORR/OER bifunctional electrocatalyst, porous nitrogen-doped carbon nanosheet decorated with high valence tungsten doped Co2P nanoparticles, has been developed for efficient Zn-air battery through salt template in this work. This catalyst exhibits high ORR (half-wave potential of 0.861 V) and OER activities (overpotential of 310 mV). The results of density functional theory calculation verify that the introduction of high valence tungsten dopants is advantageous to regulate the electronic structure of Co2P, thereby has effectively optimized the adsorption energy of intermediate species for ORR/OER and density of states. Meanwhile, the energy barrier of the rate-determining step is greatly lowered. Assembled Zn-air battery (ZAB) exhibits a promising open-circuit voltage of 1.50 V, good power density (224.4 mW cm−2), excellent specific capacity (881 mAh g−1), and durability (130 h). This work elucidated that creating high-performance transition-metal based electrocatalysts for rechargeable Zn-air batteries would be feasible using 5d high valence metal ion doping.