A review on lithium iron phosphate cathode materials

Globally, the development of a high-power lithium-ion battery is focused on lithium manganese oxide batteries, lithium cobalt nickel manganese batteries and lithium iron phosphate batteries. Lithium iron phosphate is regarded as a practical and popular cathode material for high power lithium-ion batteries due to its high capacity, high rate capability, long cycle life, superior thermal stability and good high-temperature performance. However, the problems associated with commercial production of lithium iron phosphate material are its difficult manufacturing processes and poor material reproducibility. We combined a number of innovative concepts and techniques in the fabrication processes for high quality lithium iron phosphate. Two methods: carbon coating on the surface of the powders and metal cations doping into the crystal lattice have been used to enhance the electronic conductivity and lithium-ion diffusion of LiFePO₄ material, respectively. Moreover, effective control of carbon content, surface area, uniformity of carbon layers, and particle-size distribution of powder materials were also used for the production of LiFePO₄ with good reproducibility. In this paper, some pertinent results from the above work will be reviewed and discussed.