A polyethylene glycol-assisted carbothermal reduction method to synthesize LiFePO4 using industrial raw materials

Olivine LiFePO4 is synthesized by a carbothermal reduction method (CTR) using industrial raw materials with polyethylene glycol (PEG) as a reductive agent and carbon source. A required amount of acetone is added to the starting materials for the ball milling process and the precursor is sintered at 973 K for 8 h to form crystalline phase LiFePO4. The structure and morphology of the LiFePO4/C composite samples have been characterized by X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, energy-dispersive spectroscopy, differential scanning calorimetry and magnetic susceptibility. Electrochemical measurements show that the LiFePO4/C composite cathode delivers an initial discharge capacity of 150 mAh g(-1) at a 0.2C-rate between 4.0 and 2.8 V. and almost no capacity loss is observed for up to 50 cycles. Remarkably, the cell can sustain a 30C-rate between 4.6 and 2.0V, and this rate capability is equivalent to charge or discharge in 2 min. The simple technique, low-cost starting materials, and excellent electrochemical performance make this process easier to commercialize than other synthesized methods. (C) 2010 Elsevier B.V. All rights reserved.