Flexible supercapacitors based on vertical graphene/carbon fabric with high rate performance

Vertical graphene (VG) is a remarkable electrode material for supercapacitors due to its large specific area, open channel structures, and numerous exposed edges with high electrochemical activity. However, flexible supercapacitors with high rate performance based on VG have yet to be investigated. Here, we report flexible supercapacitors based on VG, carbon fabric (CF) current collector, and H2SO4 gel polymer electrolyte. VG/CF presents an exceptional electrochemical performance in H2SO4 compared with other aqueous and liquid ion electrolytes. The flexible VG/CF supercapacitor demonstrates a 73% capacitance retention after increasing the charge-discharge rate by 200 times from 0.1 mA cm−2 to 20 mA cm−2. This high rate performance facilitates a high power density of 13.2 mW cm−2 with an energy density of 86.6 μWh cm−2. Furthermore, the electrochemical performances remain mostly unchanged after long-term charge-discharge cycles and mechanical bending. Our results demonstrate a flexible VG/CF supercapacitor with outstanding rate performance and stability for innovative high power energy and electronic devices.