SnS@Co1-xS nanocubes anchored in reduced graphene oxide sheets for sodium-ion batteries with enhanced rate performance

Metal sulfide has recently emerged as an attractive anode material for sodium-ion batteries (SIBs) with large layer spacing and desirable electrochemical reversibility, but its low-rate performance and severe volume expansion during cycling immensely hinder further application. In this work, SnS@Co1-xS nanocubes are uniformly anchored in the conductive reduced graphene oxide (rGO) network through a straightforward coprecipitation and vulcanization process. The obtained SnS@Co1-xS-rGO composite with tunable morphologies can achieve the high dispersion of nanoparticles and enhanced charge transfer kinetics simultaneously. Consequently, this SnS@Co1-xS-rGO electrode possesses an impressive cycling performance of 571.23 mAh/g at 0.1 A/g after 80 cycles and sustains a high-rate capacity of 352.92 mAh/g at a high current density of 10 A/g, which is far outperforming reported tin/cobalt sulfides. It can be demonstrated that rGO plays an important role in the capacity stability of bimetallic sulfides.