Characterization of Sol-gel Synthesized LiFePO4 by Multiple Scattering XAFS

X-ray Absorption Spectroscopy (XAS) was used to investigate the local structure arrangements of sub-microcrystalline lithium iron phosphate and its precursors. The former material, proven to be very promising as active cathode material in lithium metal and lithium-ion batteries, was synthesized through a new procedure that combines a simple sol-gel precipitation with a moderate temperature (e.g., low cost) heat treatment. X-Ray Absorption Near Edge Structure (XANES) and Extended X-Ray Absorption Fine Structure (EXAFS) spectra taken at the Fe K-edge pointed out the modification of the Fe site during the synthesis steps that allow to produce the sub-micron size crystalline LiFePO4 (active material) useful for batteries applications. The XAS investigation has shown that such a material is different from the conventional crystalline LiFePO4 on the short range order. The difference is attributed to the synthesis procedure.