Synthesis of Mg-LiFePO4/C composite using intermediate FePO4·2H2O from Fe3(PO4)2·8H2O as precursor via an aqueous rheological phase assisted method

In this work, a Mg-LiFePO4/C composite was synthesized by an aqueous rheological phase assisted method using intermediate FePO4·2H2O, which was prepared from lost cost Fe3(PO4)2·8H2O precursor. The oxidation process of Fe3(PO4)2·8H2O, rheological phase technology and Mg ion doping improved the purity, elements uniformity, as well as ionic and electronic conductivities of LiFePO4 materials, resulting in the enhanced electrochemical performances of Mg-LiFePO4/C composites. The as-synthesized Mg-LiFePO4/C composite exhibited higher specific capacity and more superior rate capability with a discharge capacity of 153 mAh g−1 at 0.2 C and 130 mAh g−1 at 5 C, compared with the undoped LiFePO4/C and the Mg-LiFePO4/C composite synthesized directly using the Fe3(PO4)2·8H2O as precursor. This provides an economical and environmentally friendly way for production of LiFePO4 materials as cathode material in lithium ion batteries.