Defect and Surface Area Control in Hydrothermally Synthesized LiMn0.8Fe0.2PO4 Using a Phosphate Based Structure Directing Agent

As confirmed by ion coupled plasma-optical emission spectroscopy and powder X-ray diffraction, stoichiometrically pure samples of olivine type LiFe0.2Mn0.8PO4 in the presence of a phosphoric acid ester based structure directing agent have been prepared. A Rietveld analysis of X-ray and n0 diffraction data suggests that the solids are largely free of defect occupation of Fe at the lithium sites. This is confirmed by 57Fe-Mößbauer spectroscopic investigations. The use of the structure directing surfactant results in significantly higher specific surface areas (SSA) and smaller particle sizes as compared to samples prepared without using a surfactant.