ZIF-derived sulfides with tremella-like core-shell structure for high performance supercapacitors.

ABSTRACT

Metal-organic frameworks (MOFs) have emerged as promising active electrode materials in supercapacitors for its controllable porous structure and excellent physio-chemical properties. However, the poor conductivities keep it from achieving its full capacitance potential, which greatly limits its practical application. Here, a facile pathway is reported to fabricate the GO/Ni2ZnS4@NiCo2S4 composite with large specific surface area and favorable electrical conductivity. Thanks to the novel tremella-like core-shell structure and high-efficient synergistic effects among multi-components, the designed GO/Ni2ZnS4@NiCo2S4 electrode shows a high specific capacitance of 2284 F/g at 1 A/g. Furthermore, the asymmetric supercapacitor fabricated by coupling GO/Ni2ZnS4@NiCo2S4 positive electrode with biological carbon negative electrode achieves a remarkable energy density of 120 Wh kg-1 at a power density of 750 W kg-1.