Electrochemical and Thermal Studies of Carbon-Coated LiFePO4 Cathode

The carbon-coated LiFePO4 Li-ion cathode material was studied for its electrochemical and thermal performance. This electrode exhibited a reversible capacity corresponding to more than 90% of the theoretical capacity when cycled between 2.5 and 4.0 V. The material also showed good capacity retention at high powers, implying that the carbon coating improves the electronic conductivity and hence the cycling of this material. The diffusion coefficient of this material was calculated from its electrochemical impedance spectroscopy. The heat generation during charge and discharge was studied using an isothermal microcalorimeter. Thermal studies were also investigated by using a differential scanning calorimeter and an accelerating rate calorimeter, which showed that LiFePO4 is safer than the commonly used lithium metal oxide cathodes with layered structures.