Performance and morphology of centrifugally spun Co3O4/C composite fibers for anode materials in lithium-ion batteries

Centrifugally spun polyacrylonitrile (PAN) microfibers surface-coated with Co3O4 nanoparticles were prepared as precursors to produce coated Co3O4 carbon-fiber (CCF) composites for lithium-ion battery anodes. The Co3O4/C composite-fiber anodes were obtained after the stabilization of surface-coated Co3O4/PAN fibers at 200 degrees C for four hours, and subsequent carbonization at 600 degrees C for 6 hours. The electrochemical performance of the Co3O4/C composite-fiber anode with different active material loading was evaluated by using galvanostatic charge/discharge, rate performance, cyclic voltammetry, and electrochemical impedance spectroscopy experiments. The CCF anode delivered a specific charge capacity of 632 and 420 mAh g(-1) after 100 cycles at 100 and 200 mA g(-1), respectively, and exhibited good rate capability. An improved electrochemical performance of the CCF was observed compared to the carbon-fiber (CF) anode (300 mAh g(-1)), which was attributed to the interaction between CFs and Co3O4 nanoparticles. The synthesis method presented in this work can provide an effective avenue for the fabrication of surface coated-fiber materials, including free-standing anode materials for lithium-ion batteries with increased specific capacity and improved electrochemical performance compared to carbon-fiber electrodes.