Conducting polymer/graphene hydrogel electrodes based aqueous smart Supercapacitors: A review and future prospects

•Conducting polymer hydrogels as electrode are considered the most promising to fabricate flexible supercapacitors.•Three-dimensional porous network structure of hydrogel supports the diffusion of electrolyte ions.•Graphene hydrogels as electrode are stable and highly efficient.•Conducting hydrogels possess exciting future perspectives by offering niche applications in numerous fields based on their rich surface chemistry.