Hydrogen reduction of vanadium in vanadium-doped LiMnPO4

Abstract The samples of vanadium-doped LiMnPO 4 have been synthesized by the solid-state reaction technique. To reduce the oxidation state of vanadium from V 5+ to V 4+ , the samples have been additionally annealed under hydrogen atmosphere. The tetravalent state of vanadium was proved by analysis of V 2p X-ray photoelectron spectra. Raman spectroscopy, first-principle studies and magnetic measurements were used to determine the effect of V 4+ on the Li–Mn phosphate properties.