In-situ preparation of graphene/poly(styrenesulfonic acid-graft-polyaniline) nanocomposite via direct exfoliation of graphite for supercapacitor application

Graphene/poly(styrenesulfonic acid-graft-aniline) (Gr/S-g-A) nanocomposites are prepared through direct exfoliation of graphite using S-g-A as a surfactant. Compared with other fabrication methods of graphene/polyaniline composites such as in-situ polymerization and electrochemical polymerization, the direct exfoliation method yields higher quality of graphene and also minimizes the number of composite preparation steps, because graphite is directly used as a precursor for graphene without chemical treatment and thus the composite is easily fabricated by simply mixing graphite and the surfactant polymer. The in-situ prepared nanocomposite of Gr/S-g-A exhibits a superior specific capacitance of 767 F g−1 at a current density of 0.5 A g−1, which is one of the highest values among supercapacitor electrodes based on graphene/polyaniline composites. This high value of specific capacitance is attributed to taking both advantages of high specific area of graphene and high pseudo-capacitance of polyaniline. The Gr/S-g-A nanocomposite also retains 92% of its initial capacitance after 5000 cycles, indicating high electrochemical cyclic stability.