MOF derived hierarchical carbon-enhanced MCo2S4 for high-performance hybrid supercapacitors

Abstract Ternary transition metal sulfides have attracted great research attention as effective pseudocapacitive electrode materials for high-performance supercapacitors. Herein, hierarchical carbon structure is derived from 2D zeolitic imidazolate framework to enhance overall electrochemical performances of MCo2S4 (M = Fe, Ni) nanospheres. Due to a positive synergistic effect induced by carbon substrate with excellent conductivity and the MCo2S4 with high electrochemical activity, the composite (C@MCo2S4) exhibits a specific capacity of 342.5 mAh g−1 at a current density of 1 A g−1 and a capacity retention of 69% at 10 A g−1. In addition, a hybrid supercapacitor with C@MCo2S4 and soybean derived porous carbon as the positive and negative electrodes delivers a high energy density of 45.9 Wh kg−1 at a power density of 775 W kg−1.