Enhanced electrocapacitive performance for the supercapacitor with tube-like polyaniline and graphene oxide composites

Polyaniline (PANI) is one of the most attractive materials for pseudocapacitors. To enhance the electrolyte diffusion and improve the electrochemical performance of the electrode, the well-designed morphology of PANI is required. Incorporating carbon materials is also benefic on enhancing the cycling stability as well as the mechanical and electrochemical properties of PANI. In this study, a simple solution method is applied to synthesize the particle-deposited tube-like PANI. Due to the well-defined structure, a specific capacitance (C_F) of 437.8 F/g is achieved at the current density of 4 A/g. Furthermore, the self-synthesized graphene oxide (GO) is simply mixed with the particle-deposited tube-like PANI to make a more efficient electrocapacitive material. An enhanced C_F value of 475.0 F/g is achieved for the optimized PANI/GO electrode, owing to the synergic effects of the pseudo-capacitance from PANI and the functional groups of GO, as well as the electrochemical double-layered capacitance from GO. After conducting 2000 cycles repeated charge/discharge process, the C_F retention of 90% and the average Coulombic efficiency of higher than 90% are also attained for the optimized PANI/GO electrode.