Synthesis of benzenesulfonated PANI/RGO as cathode material for rechargeable lithium-polymer batteries

Graphene oxide (GO) was synthesized by the modified Hummers method and then reduced with NaBH4 to form RGO with a regular layered structure. The graphene oxide is benzenesulfonated to obtain a functionalized graphene material (RGO-BS). The benzenesulfonated polyaniline/RGO composite (PANI/RGO-BS) was prepared by adsorption double oxidation method using RGO as template. Some physical characterization methods (X-ray diffraction, Fourier-transform infrared spectroscopy, and scanning electron microscopy) were used to analyze the morphology and crystallinity of the composite. The electrochemical properties were characterized by cyclic voltammetry, impedance spectroscopy, galvanostatic charge/discharge, and rate capability. The initial discharge specific capacities of oxidized PANI/RGO-BS and reduced PANI/RGO-BS were 165.4 and 176 mAh/g. After 100 cycles, the capacity retention rates were 92.6% and 96%, the coulombic efficiency of the battery is close to 100%. These results indicate functionalized composite has exciting potentials for the cathode material of lithium-ion battery.