Submicron LiFe1−yMnyPO4 solid solutions prepared by mechanochemically assisted carbothermal reduction: The structure and properties

Homogeneous submicron carbon-coated LiFe1−yMnyPO4 solid solutions in the whole concentration range (0 ≤ y ≤ 1) were obtained by mechanochemically assisted carbothermal reduction of Fe2O3 and MnO2, using high-energy planetary mill. The samples were studied through a combination of several techniques: XRD, TEM, FTIR, Mössbauer, 6,7Li and 31P NMR spectroscopy and magnetic measurements. NMR study and magnetic measurements revealed the presence of tiny amounts of structural defects and ferromagnetic-like impurities with a Curie temperature above RT differing upon the sample composition. Electrochemical cycling of as prepared LiFe1−yMnyPO4 showed that, despite high homogeneity and fine particles, noticeable capacity loss is observed with increased Mn content, mainly in the Mn2+/Mn3+ range.