Phospho-olivine as advanced cathode material for lithium batteries

Nano-sized and micron-sized LiFePO₄ electrode materials were prepared by a sol gel and coprecipitation reactions. An improvement of the cycling and rate performances in lithium cells was observed for the carbon coated LiFePO₄ materials. The coating process uses a solid/gas-phase reaction which consists of decomposing propylene gas, as carbon source, inside a reactor containing olivine LiFePO₄ materials. Optimized LiFePO₄ electrode cells, cycled at RT between 3.0 and 4.3 V at a C/10 rate, do not show any sign of capacity fade during the first 50 cycles. Combination of the high volumetric energy density and low cost preparation method makes the micron-sized LiFePO₄ olivine an attractive safe cathode for lithium-ion batteries.