LiMn2O4 nanocrystalline electrode materials

The process of sol-gel synthesis was applied to obtain the LiMn2O4 nanopowders. The samples were characterized by the following methods: scanning electron microscopy (SEM/EDX), X-ray photoelectron spectroscopy (XPS), SQUID magnetometry and electron paramagnetic resonance (EPR). Chemical composition, oxidation state of manganese and magnetic properties were determined. The SEM images showed grains in the form of nanocrystals or larger conglomerates, depending on the synthesis process. From XPS analysis chemical formulas of the examined compounds were determined. Deconvolution of complex Mn3p lines was used to find the ratio of Mn3+/Mn4+. This ratio was observed to depend on the synthesis process. The C1s lines of the measured samples were intense and complex. The results of magnetic measurements and EPR showed the presence of some extra magnetic phases. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)