Synthesis of polyaniline/graphene composite and its application in zinc-rechargeable batteries

Polyaniline, polyaniline/graphene composites were synthesized by a novel in situ chemical oxidative polymerization method including two oxidants. The morphology and structure of the material were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The electrochemical performance of polyaniline (PANI)-based composites was tested by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) testing, and constant current charge and discharge (GCD) tests. At 0.2 C of constant current, the discharge specific capacities of PANI/graphene oxide (PANI/GO) and PANI/GO-sodium borohydride (graphene oxide is reduced by sodium borohydride, named PANI/GO-NaBH4) were as high as 183 mAh/g and 192 mAh/g, respectively, which was nearly twice as high as that of PANI (100 mAh/g). After 100 charge and discharge cycles, the capacity retention rates of PANI, PANI/GO, and PANI/GO-NaBH4 were 80.4%, 89.4%, and 95.05%, respectively; the cycle performance was greatly improved before the modification. These results indicate that the composite has exciting potentials for the cathode material of zinc-rechargeable battery.