Solid-type supercapacitor of reduced graphene oxide-metal organic framework composite coated on carbon fiber paper

A composite material of reduced graphene oxide (rGO) and Hong Kong University of Science and Technology-1 (HKUST-1) metal organic framework (MOF) was produced and used as the supercapacitor electrode material. Pure HKUST-1 has a microporous structure with poor conductivity limiting its electrochemical applications while loading rGO to HKUST-1 leads to a novel composite with a mesoporous structure and good electrochemical properties. 10 wt.% rGO/HKUST-1 has a high BET surface area of 1241 m 2 g −1 , a specific pore volume of 0.78 cm 3 g −1 , and an average pore diameter of 8.2 nm, which is a proper pore size to allow uptaking and releasing of electrolytes. A half-cell electrode of 10 wt.% rGO/HKUST-1 coated on flexible carbon fiber paper (CFP) exhibits a high specific capacitance of 385 F g −1 at 1 A g −1 while pure HKUST-1 stores only 0.5 F g −1 . A 1.8″ × 4.0″ symmetric solid-type supercapacitor of the 10 wt.%rGO/HKUST-1 exhibits a specific power of 3100 W kg −1 and a specific energy of 42 Wh kg −1 . The supercapacitor can practically supply electricity to a spinning 3-V motor over 9-min discharging time.