Facile preparation of polyaniline covalently grafted to isocyanate functionalized reduced graphene oxide nanocomposite for high performance flexible supercapacitors

[Display omitted] Graphene oxide nanosheets (GO) is simultaneously reduced and functionalized by isophorone diisocyanate (IPDI), followed by grafting polyaniline (PANI) in mild condition to produce a novel PANI-IPDI-rGO composite useful for supercapacitors application. The structural and morphological analysis indicates only a few nanometers thickness of emeraldine salt form of PANI layer is anchored to the surface of rGO sheets. On account of high pseudo-capacitance of PANI, high conductivity of graphene scaffolds and the synergistic effect between the components, the PANI-IPDI-rGO electrode shows dramatically optimized gravimetric specific capacitance of 1415 F/g without compromising rate capability, which is much higher than that of PANI/rGO non-functionalized composites. In addition, the assembled all-solid-state supercapacitor device based on PANI-IPDI-rGO positive electrode exhibits high electrochemical performance, such as a remarkable gravimetric specific capacitance of 485 F/g (9.1 F/cm3), superior energy storage capacitance with maximum energy density of 113.8 Wh/kg (2.07 mW h/cm3), and excellent capacitance retention of 95 % after 2000 consecutive charge-discharge cycles. Preliminary results reveal that the effective synthesis strategy paves an alternative avenue for nanostructure hybrid electrode materials in wearable and portable energy storage systems.