LiFePO 4 synthesized via melt synthesis using low-cost iron precursors

LiFePO 4 /C material has been prepared using fast-melt synthesis method followed by grinding and carbon coating. The low-cost iron ore concentrate (IOC) and purified iron ore concentrate (IOP) were used as iron precursors in the melt process to reduce significantly the cost of LiFePO 4 /C. The same product was also synthesized using pure Fe 2 O 3 under similar conditions as reference. The physical-chemical and electrochemical properties of samples were investigated. The X-ray Diffraction (XRD) results confirm the formation of an olivine structure of LiFePO 4 with a minor amount of Li 3 PO 4 and Li 4 P 2 O 7 impurities for all the samples but no Fe 2 P. The power performances of LiFePO 4 /C using low-cost iron precursors were close to the sample using pure Fe 2 O 3 precursor although capacity in mAh g −1 is somewhat lower. With the inherent presence of silicon and other metals species, multi-substitution may take place when using IOC as source of iron leading to a Li(Fe 1-y M y )(P 1-x Si x )O 4 general composition. Multi-substitution, however, allows a better cycling stability. Therefore, these iron precursors present a promising option in this field to reduce the cost of a large-scale synthesis of LiFePO 4 /C for Li-ion batteries application.