Template-assisted synthesis of mesoporous transition metal iron triad sulfide/carbon nanocomposites for electrochemical energy storage

Transition metal sulfides (TMSs) exhibit as a kind of promising materials in the field of supercapacitors, owing to the large interlayer space and high theoretical capacity. Unfortunately, several key challenges, such as huge volume changes and sluggish reaction kinetics, limit the practical application of TMSs for energy storage. Herein, a series of mesoporous metal iron family sulfides/carbon nanocomposites (MxSy/C, M = Fe, Co, Ni) with rod-like structures were synthesized through template regulation. The mesoporous silica framework provides confined channels to prevent the growth of TMSs, reaching a superior capacitance and cyclability. At a current density of 0.5 A g(-1), CoxSy/C nanocomposites could reach a specific capacitance of 1012 F g(-1), superior to both FexSy/C and NixSy/C. Meanwhile, CoxSy/C nanocomposites could retain a capacitance of similar to 80 % after 5000 cycles at 5 A g(-1). The as-obtained CoxSy/C nanocomposites with well-designed mesoporous framework give insights to the subsequent development of TMSs for high-performance supercapacitors.