Self-assembled activated carbon sandwiched graphene film for symmetrical supercapacitors

Activated carbon (AC) particles sandwiched reduced graphene oxide sheets (rGO) film has been successfully fabricated via a facile self-assemble approach. The as-formed AC/rGO film is self-standing, flexible and mechanically robust, allowing to be transferred to any substrate on demand without rupture. Since AC particles effectively suppressed the restacking of the rGO sheet, AC/rGO film exhibits loose layer-by-layer stacking structures with various gaps between AC particles and rGO sheets, which is different from compact structures of pure graphene films. The as-formed gaps provide fast diffusion channels for electrolyte ions and enhanced accessible surface area of rGO. Therefore, the AC/rGO electrode delivers improved electrochemical performance over the voltage range of 0.0—3.0 V. This work offers a promising strategy to design free-standing supercapacitor electrodes based on traditional nanocarbon materials.