Carbon nanotube-modified LiFePO₄ for high rate lithium ion batteries

A hybrid cathode material for high rate lithium ion batteries was prepared by ball-milling and spray drying a slurry containing LiFePO₄ nanoparticles, glucose and carbon nanotubes (CNTs) in water, followed by pyrolysis at 600 for 6 h under a gas mixture of 5% H₂ in Ar. CNTs with a large aspect ratio form a continuous conductive network connecting the LiFePO4 nanoparticles and amorphous carbon, which significantly reduces the electrical resistance of the cathode. The hybrid material can deliver a specific capacity of 99 mAh / g at a 50 C charge / discharge rate. An excellent cycling performance was also demonstrated, with a capacity loss of less than 10% after 450 cycles at a 10 C rate.