Sulfur defects engineering enables high-performance manganese sulfide anode

Abstract

Poor intrinsic electrical and ionic conductivity has severely impeded the applications of high-capacity sulfide anodes such as α-MnS. Defects engineering has been proven effective to alleviate the dilemma. While α-MnS also undergoes huge volume variation upon cycling. We here report the synergistic effect of pomegranate composite structure and S detect for MnS anode to address these issues. Sufficient S vacancies are implanted onto fine MnS nanoparticles (NPs) confined in N, S-codoped mesoporous carbon host, which can improve the electric conductivity and modulate electronic structure to enhance Li+ conversion redox, suggested by theoretical calculations. Continuous carbon networks act as electron highways, and physical barrier that confines MnS NPs size and defines the formation of solid electrolyte interphase, where abundant voids are retained to tolerate volume evolution. Thereby optimal MnS/C composite anode achieves notably improved cycling performance (460 mAh g−1 maintained after 1500 cycles at 1.6 A g−1). Operando optical observation validates the advantages of such a pomegranate nanostructure through maintaining structural integrity.