Metal-organic framework-derived carbon coated copper sulfide nanocomposites as a battery-type electrode for electrochemical capacitors

Metal-organic framework (MOF)-derived carbon-coated metal sulfides are a popular research area for energy storage, owing to their highly reactive nature and universal electrochemical activity. A simple and efficient method for the preparation of carbon-coated copper sulfide via a calcining-hydrothermal process using an MOF template is presented in this paper. The transmission electron microscope (TEM) imaging indicates that the cobble-like Cu7S4 nanopolyhedra are ∼100 nm in size, and are interconnected by amorphous carbon. Electrochemical analysis shows that the Cu7S4/C electrode possesses the highest capacitance, 321.9 F g−1 (80.5 mAh g−1 in capacity), at a current density of 0.5 A g−1, and achieves nearly 78.1% capacitance retention after 3000 cycles, suggesting its holds promise for application in battery-type electrode materials for supercapacitors.