Abstract
Carbon-coated LiCoPO4 which is a high voltage cathode material for lithium secondary battery was prepared under hydrothermal condition and its electrochemical property was compared with carbon-coated LiFePO4 and carbon-coated LiMnPO4 prepared under same condition. Highly crystallized particles of LiCoPO4 without impurity phase were obtained successfully. Particle size were almost same (250 – 500 nm) among the samples. Raman spectra indicated that carbon layer on the LiCoPO4 would be thinner than that on the LiFePO4 and the LiMnPO4. Discharge capacities of the LiFePO4 and the LiMnPO4 were 155 and 109 mA h g-1, respectively, and LiCoPO4 was 45 mA h g-1, 27% of theoretical capacity. Such low capacity of the LiCoPO4 would be attributed to the thin carbon layer which could not provide enough electronic conductivity. To prepare high performance LiCoPO4, optimization of hydrothermal condition to form thick carbon layer is required.
