▎ 摘　　要

Stacking of Graphene usually results in a close packing of graphene nanosheeets corresponding to a low specific surface area and pore volume. A new simple method to prepare reduce graphene oxide (rGO) film has been developed using an in situ electrochemical reduction of the as-formed GO hydrogel film in an aqueous solution electrolyte. The as-obtained rGO hydrogel film has a highly specific surface area and was directly used as the electrodes for a supercapacitor, in which the ion channels remained with excellent capacitance, even at a high current density. The as-obtained rGO hydrogel film has also been used to prepare a flexible belt-like supercapacitor, which may light up a LED lamp for more than two minutes. Electrochemical in situ reduction provides a simple method to prepare novel graphene based supercapacitors for a wide variety of applications in the near future.