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 Co₃O_4/PAN fibers at 200 °C for four hours, and subsequent carbonization at 600 °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. Graphical abstract: [Figure not available: see fulltext.].