A simple, cheap soft synthesis routine for LiFePO4 using iron(III) raw material

An order olivine structure LiFePO4 was synthesized with a simple rheological phase reaction (RPR) of LiOH·H2O and FePO4·4H2O in the presence of PEG as a reductive agent and carbon source. A required amount of water was added to the starting materials to form the rheological precursor and decomposed at 700 °C to form the crystalline phase LiFePO4 directly, without ball-milling, preparation of intermediates, pre-sintering and post-deposition treatment. Fine particles with an average particle size about 216 nm are examined by scanning electron microscopy (SEM) and optical particle size analyzer. An initial discharge capacity of 157 mAh g−1 was achieved for the as-prepared LiFePO4 material with a rate of 0.1C (17 mA g−1), whatʹs more, this material shows excellent specific capacity, charge–discharge efficiency and cycle efficiency at high current rates, almost no capacity loss can be observed up to 40 cycles with the rate of 1, 2 and 3C at room temperature. The simple, cheap process as well as the excellent high-rate performance makes this RPR method feasible commercially.