Appropriate amount of polyaniline coated Co3O4 nanofibers and their excellent electrochemical properties

Co3O4/PANI composites with different proportion were synthesized by in-situ polymerization method. The morphology of the composites showed that cobalt oxide fibers were wrapped up in polyaniline (PANI). The electrochemical tests showed that Co3O4/PANI (1:5) had the highest specific capacitance of 1124 F g(-1) among the all samples. Its capacitance retention was up to 82.19% after 2000 charge-discharge cycles at 5 A g(-1). Especially, after 5000 cycles, the capacitance retention was 73.97%, showing excellent cycling stability. It was found that the combination of PANI and cobalt oxide fiber in proper proportion was beneficial to the conductivity and ion diffusivity of the system, and was also beneficial to improve the redox efficiency of cobalt oxide. This is synergistic effect, which can bring good electrochemical performance to the system.