The characterization of commercial and home-made non-stoichiometric Li-rich manganese oxide spinels covered by poly(3,4-ethylenedioxythiophene) (pEDOT) chemically grown on the oxide particle surface is reported. The results of the characterization of these materials by IR spectroscopy, thermogravimetric analysis, X-ray diffraction, scanning electron microscopy and laser particle size analysis are reported and compared to those of spinels without polymer covering. The results of the electrochemical tests on composite electrodes based on the pEDOT-covered spinels are compared to those of electrodes based on spinels without polymer covering, and demonstrate the reliability of this new composite polymer material as a positive electrode for lithium-ion batteries, also confirmed by preliminary tests in battery configuration.