In situ synthesis of cobalt doped polyaniline modified graphene composites for high performance supercapacitor electrode materials

► Gr/Co/PANI was prepared by in situ oxidative polymerization method. ► Band gap also calculated and it shows that doping causes highly decrease of the band gap of Gr/Co/PANI than other composites. ► Specific capacitance of the Gr/Co/PANI nanocomposite was found to be higher than the Gr/PANI nanocomposites. ► The energy and power densities also showed promising values for the application in the field of supercapacitor. ► Thermal stability of the Gr/Co/PANI also increases upon transition metal doping with polyaniline.