Preparation of self-supporting graphene on flexible graphite sheet and electrodeposition of polyaniline for supercapacitor

A graphene-based composite was prepared by the in-situ growth of a self-supporting graphene (SSG) on a flexible graphite sheet (FGS) via electrochemical intercalation of FGS and then the electrodeposition of a thin, homogeneous, and conformal polyaniline (PANI) film. The maximum areal capacitance of 1.36 F cm−2 and specific capacitance based on PANI of 491.3 F g−1 were achieved for the prepared FGS-SSG/PANI composite. The good cycling stability of FGS-SSG/PANI was proved by cyclic voltammetry at a scan rate of 50 mV s−1 for 3000 cycles. The symmetric supercapacitor device assembled using FGS-SSG/PANI composite electrodes exhibited a high energy density of 46 W h kg−1 at a power density of 275 W kg−1 on the basis of the total mass of PANI (∼ 10% of the total mass of the flexible electrodes). The good electrochemical properties indicate that the FGS-SSG/PANI is a promising flexible electrode for supercapacitors.