Mild hydrothermal synthesis and crystal morphology control of LiFePO4 by lithium nitrate

Abstract

Lithium iron phosphate (LiFePO4) with olivine structure was prepared by mild hydrothermal method at variable time, temperature, source of lithium and sucrose content. The relations between synthesis parameters and the characteristics (phase purity, lattice volume and morphological relations) of the obtained iron olivine samples were studied by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results demonstrated that after a proper adjustment of the initial pH, lithium nitrate (LiNO3) becomes an effective alternative to lithium hydroxide (LiOH) as source for lithium. Conditions that provide LiFePO4 with adjustable lattice volume and new morphological features have been established. To our knowledge, this is the first mild hydrothermal synthesis of LiFePO4 using LiNO3. Further, it is demonstrated that it can be applied for the development of Li-ion battery electrodes.