Control of the LiFePO4 electrochemical properties using low-cost iron precursor in a melt process
Idioma
en
Article de revue
Este ítem está publicado en
Journal of Solid State Electrochemistry. 2016, vol. 20, n° 12, p. 3481–3490
Springer Verlag
Resumen en inglés
LiFePO4 was prepared from low-cost iron ore concentrate (containing 4.48 wt.% SiO2 and MgO, CaO and Al2O3 below 0.5 wt.% as contaminant) using a melt synthesis. X-ray diffraction (XRD) refinement associated with Mössbauer ...Leer más >
LiFePO4 was prepared from low-cost iron ore concentrate (containing 4.48 wt.% SiO2 and MgO, CaO and Al2O3 below 0.5 wt.% as contaminant) using a melt synthesis. X-ray diffraction (XRD) refinement associated with Mössbauer spectroscopy and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDX) analyses are used to track the location of Si in the material. It is shown that the iron content in the melt can be used as a means to control the doping rate of elements from iron ore concentrate (IOC) precursor according to the formula (Li1 − zAz)(Fe1 − yMy)(P1 − xSix)O4. Electrochemical behavior of the material is affected by the doping of LiFePO4. While capacity is decreased in doped material, the cycling stability is much improved. When dopants are out of LiFePO4 structure, capacity retention dramatically drops as well as capacity due to the gravimetric impact of impurity phases. A trade-off between high capacity and best cycling performance is necessary. For instance, slight lack of iron in the melt (6 % deficiency) leads to a capacity only 2 % lower than that of pure Fe2O3-based material for the same stoichiometry and fairly good capacity retention.< Leer menos
Palabras clave en inglés
LiFePO4
Melt synthesisIron
Iron ore concentrate
Compositions
Impurities
Orígen
Importado de HalCentros de investigación