Engineering graphene aerogels with porous carbon of large surface area for flexible all-solid-state supercapacitors

Graphene nanosheets, typical two-dimensional sp2 hybridized carbon materials, are gaining increasingly attention in many fields due to their excellent electrical and large surface area. As electrode materials for supercapacitors, however, intrinsic large surface area of graphene is generally suppressed because of the unexpected re-stacking upon the processes. The mostly used method for address this issue is to insert “spacers” between into graphene interlayers, including metal oxides and other carbon materials. Since the structure instability limits the use of metal oxides, carbon materials play the main role in prohibiting graphene restacking. Herein, we synthetized a novel porous carbon with the lager surface area of 2211 m2 g−1 for achieving three-dimensional (3D) graphene/porous carbon (LGN/PC) aerogel through the facile hydrothermal method. The resulting binder-free electrode based on the LGN/PC shows excellent electrochemical performance in three-electrode cell in the 6 M KOH aqueous electrolyte, with the highest capacity observed up to 410 F g−1 at 0.1 A g−1. Moreover, the all-solid-state supercapacitor based on the 3D LGN/PC exhibits no significant capacitance loss after 10,000 cycles at a current density of 5 A g−1 and no capacity loss was observed upon bending.