Effects of carbon source on performance of Li₃V₂(PO₄)₃/C Cathode Materials synthesized via carbon thermal reduction for Li-ion batteries

Effects of the source of carbon on properties and performance of Li₃V₂(PO₄)₃/C composite cathode materials were studied using five different carbon containing materials (sucrose, graphite, carbon nanotubes, citric acid, and carbon black) in synthesis via the carbothermal reduction method. It was found that the electrochemical performance of the cathode material was greatly dependent on particle size, carbon content, and electron conductivity, which were all functions of the carbon source. When the ratio of carbon to vanadium was tentatively fixed at 1.25, Li₃V₂(PO₄)₃/C synthesized with carbon nanotubes showed the best electrochemical performance due to a high carbon content and uniformly distributed small particle size. In the further optimization of the ratio of carbon to vanadium in sucrose-synthesized cathode materials, sucrose was verified as more suitable carbon source and able to achieve to higher cathode performance.