Mechanically strong high performance layered polypyrrole nano fibre/graphene film for flexible solid state supercapacitor

Paper like flexible electrode becomes one of the most important research objects recently in request of the fast expanding market of portable electronics. Flexible solid state supercapacitors are shortlisted as one of the most promising energy devices to power electronics with medium to high power density requirements. In this work, we developed a simple but effective way to produce a mechanically strong and electrochemically active RGO/polypyrrole (PPy) fibre paper. A well-bedded microstructure was created with interlaced polypyrrole fibres evenly distributed between the graphene layers. Such microstructure can create enormous amount of pores and therefore provides larger interfaces for charge carrier storage/release. The effects of polypyrrole fibres on the film's morphologies, mechanical properties and electrochemical performance were discussed. A solid state supercapacitor was demonstrated using such paper electrodes and a gel type electrolyte-phosphate acid (H₃PO₄) infused polyvinyl alcohol (PVA). It showed a high capacitance (345 F g^-1) and an excellent cycling stability (9.4% drop after 1000 cycles).