Highly ordered LiFePO4 cathode material for Li-ion batteries templated by surfactant-modified polystyrene colloidal crystals

Abstract An organic template assisted synthesis was developed to obtain highly ordered porous LiFePO 4 cathode material. The developed synthesis enabled the use of polystyrene (PS) as template by modifying its surface with a surfactant (Brij 78) to render it hydrophilic. The material was synthesized in high yield and purity as confirmed by X-ray powder diffraction. The TEM and SEM images clearly confirmed the presence of a highly ordered porous structure and the latter showed that the structure has an average pore diameter of 400 nm and a wall thickness and depth of ∼100 nm. Thermal scans and elemental analysis showed that the material contains a high amount of carbon reaching 23–28% by weight. The surface area was calculated using the BET method and found to be 7.71 m 2  g −1 . Li/LiFePO 4 half cells were tested and gave satisfactory discharge capacities; an initial capacity (158 mAh g −1 ) close to the theoretical value and recoverable capacities at high C-rates (2–5 C).