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 oC for 6h 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.