MnS nanoparticles embedded uniformly in sulfur/nitrogen-doped porous carbon spheres enhancing lithium-storage performance

Abstract

Rocksalt-type manganese sulfide (α-MnS) is a promising next generation anode material for lithium-ion batteries, but its practice application is severely impeded by slow conversion kinetics and large volume change. To overcome these drawbacks, α-MnS nanoparticles are uniformly embedded in sulfur/nitrogen-doped porous carbon (S,N-PC) spheres, which are fabricated by absorbing Mn2+ in poly(acrylamide-co-acrylic acid) (P(AM-co-AA)) microgel spheres, in-situ generating MnS@P(AM-co-AA) hybrid spheres, and carbonized at a high temperature. Synergetic effect of nanocrystallization, carbon encapsulation and porous structure endows the MnS@S,N-PC electrode with outstanding electrochemical properties. It can deliver an initial discharge capacity of 822 mAh/g at 0.1C rate in the voltage range of 0.01–3.0 V, accompanying with an initial coulombic efficiency of 82.5 %, and remains 420 mAh/g at 2C rate after 600 cycles. Owing to a large interfacial area between MnS nanoparticles and S,N-PC, pseudocapacitance contributes much more to total capacity during charging/discharging processes. The results suggest that the MnS@S,N-PC spheres can be promisingly developed into high-performance anode materials for lithium-ion batteries.