Improved coulombic efficiency in nanocomposite thin film based on electrodeposited-oxidized FeNi-electrodes for lithium-ion batteries

► Nanocrystalline Fe-Ni oxide films are prepared by electrochemical plus thermal route. ► Li cells showed the best first-cycle efficiency/polarization in conversion anodes. ► Discharge capacities above 600 mAh/g without binder or conductive additives.