Effects of surfactant-assisted synthesis Fe3(PO4)2∙8H2O and its purity and morphology on the performance of LiFePO4/C cathode materials

The synthesis of high purity and crystallinity Fe3(PO4)2·8H2O precursor by polyvinyl pyrrolidone (PVP)–assisted co-precipitation method is reported, and the morphology-controlled tiny and uniform primary particles material has also been obtained. Moreover, the fore-mentioned Fe3(PO4)2∙8H2O was used to synthesize LiFePO4/C via carbothermal reduction. All the materials were systematically characterized by various analytical, spectroscopic, and imaging techniques. Fe3(PO4)2∙8H2O exhibits stronger affinities within primary particles and homogeneity, attributed to PVP, which can greatly improve the properties of LiFePO4/C. The resulting high purity Fe3(PO4)2∙8H2O gave highly crystalline of LiFePO4/C. In addition, LiFePO4/C prepared with PVP demonstrated excellent electrochemical performance of initial discharge capacities at 0.2 C, 0.5 C, 1 C, 2 C, and 5 C are 163.4, 160.9, 155.1, 146.2, and 126.5 mAh g−1, respectively.