Dragana Jugović

Comparison between Different LiFePO4 Synthesis Routes

Olivine-type lithium iron phosphate (LiFePO4) powders were synthesized applying three different methods: solid state reaction at high temperature, ultrasonic spray pyrolysis, and sonochemical treatment. The samples were characterized by X-ray powder diffraction (XRPD). Particle morphologies of the obtained powders were determined by scanning electron microscopy (SEM). It was found that structural and microstructural parameters of this material were strongly dependent on the synthesis conditions. We present here the results obtained upon optimization of each procedure for designing this cathode material.

NANOSTRUCTURED ZrO2 POWDER SYNTHESIZED BY ULTRASONIC SPRAY PYROLYSIS

The synthesis of nanostructured zirconia particles from aqueous colloidal dispersion of zirconia (zirconia sol) was carried out by ultrasonic spray pyrolysis method. The morphology of these nanostructured particles was characterized by scanning electron microscopy and transmission electron microscopy. The synthesized particles are spherical in shape with the avarage size of 400 nm, consisting of smaller primary particles, with the mean crystallite size of 7 nm. The tetragonal phase was confirmed by both X-ray and electron diffraction measurements.

Properties of LiMn2O4 Powders Obtained by Ultrasonic Spray Pyrolysis

LiMn2O4 powders were synthesized by ultrasonic spray pyrolysis. By varying the cooling conditions, two samples of powders were obtained: quenched in water (Q) and spontaneously cooled to room temperature (SC). The crystal structure of the as-prepared powders was revealed by X-ray powder diffraction. Structure refinements confirm that SC sample crystallizes in Fd3m space group, while Q sample crystallizes in I4l/amd space group. Particle morphology was determined by scanning electron microscopy. Electrochemical intercalation and deintercalation were examined in galvanostatic regime.