The effect of composite formation with oxides on the ion conductivity of NASICON-Type LiTi2(PO4)3 and olivine-type LiFePO4

NASICON-type LiTi2(PO4)3 and olivine-type LiFePO4 were prepared by a sol-gel method. The composites based on these phosphates with addition of amorphous SiO2 or Al2O3 were obtained by mechanical milling of preformed phosphates and oxides with further thermal treatment and by precipitation of oxide from the precursor on the surface of the preformed phosphate or its precursor with further thermal treatment. The final products were characterized by XRD, SEM and impedance spectroscopy. The formation of the composites with oxides results in the conductivity decrease in the case of LiTi2(PO4)3 and in the conductivity 5-10 fold increase in the case of LiFePO4.