Porous micro-spherical aggregates of LiFePO4/C nanocomposites: A novel and simple template-free concept and synthesis via sol–gel-spray drying method

Porous micro-spherical aggregates of LiFePO4/C nanocomposites were prepared with a process of spray drying at 200 °C and subsequent heat treatment at 700 °C for 12 h by a novel and simple template-free sol–gel-SD method independent of surfactants or templates. The results indicate that the as-obtained LiFePO4 porous microspheres have the mean diameter of 19.8 μm, average pore size of 45 nm, and large specific surface area (20.2 m2 g−1) with evenly distributed carbon (4.5 wt.%). The particles can be easily brought into contact with electrolyte, facilitating electric and lithium ion diffusion. They present large reversible discharge capacity of 137.5 mAh g−1 at the current density of 0.1 C, good rate capacity of 53.8 mAh g−1 at 10 C, and excellent capacity retention rate closed to 100% after various current densities in the region of 2.0–4.3 V.