Carbon coated Mo-doped MnSx nanoparticles integrating with sulfur vacancies as cathode for improved zinc ions storage

Abstract

Aqueous zinc-ion batteries are the next promising candidates because of high theoretical capacity and environmental friendliness. However, it is urgent to improve their electrochemical performance by designing cathode materials. Herein, the novel Mo-MnSx@C nanoparticles with optimal Mo-doping content have been designed and successfully prepared by the facile hydrothermal reaction and subsequent thermal treatment process, which integrating with rich sulfur vacancies induced by Mo-doping, high electrical conductivity by conductive carbon coating and shorten Zn2+ transmission path by ultra-nanoparticles morphology. Benefited from the synergistic contribution of abundant electroactive sites, fast Zn2+ diffusion kinetics and good structural stability, Mo-MnSx@C cathode achieved superior electrochemical performance with high specific capacity of about 427.6 mAh g-1 at 100 mA g-1 and 141.0 mAh g-1 at the high current density of 10 A g-1 along with keeping approximately 128 mAh g-1 over 1000 cycles. In addition, Mo-MnSx@C demonstrated high overpotential of Hydrogen Evolution Reaction, which increased the difficulty of hydrogen generation and improved the Zn2+ diffusion kinetics reversibly. The strategy achieved from this study provides a new direction of decorating transition metal sulfides-based cathode materials for high performance aqueous ZIBs.