Graphene-Carbon nanotube @ cobalt derivatives from ZIF-67 for All-Solid-State asymmetric supercapacitor

Abstract

Metal-Organic Framework (MOF) materials attract increasing interest for their energy storage application by converting MOF into MOF derivatives. Herein, a graphene and carbon nanotube wrapped Cobalt derivatives (Gr-CNT@Co) electrode material is prepared by annealing the complex of ZIF-67 and graphene oxide. The as-prepared Gr-CNT@ Co shows an interconnected porous structure, a high specific surface (253.9 m2g−1), and a high specific capacitance of 1108F g−1 with high cycling stability. Furthermore, the constructed all-solid-state asymmetric Gr-CNT@Co// N-doped rGO device exhibits a high energy density of 36.55 Wh kg−1 at 685.3 W kg−1, as well as an excellent cycle capacitance retention (78%) after 6000 cycles at 1.5Ag−1, which shows that Gr-CNT@Co is very promising electrode material for portable energy storage devices applications.