Growth and electrochemical characterization versus lithium of Fe 3O4 electrodes made via electrodeposition

Abstract

Interest in binary oxides has been renewed because of their novel reactivity towards Li at low potential, which leads to large capacity gains. Here, the structural, morphological, and electrochemical properties of copper-supported Fe3O4 deposits prepared by cathodic reduction of a FeIII chelate in alkaline solution are reported. By tuning the deposit growth parameters, namely the deposition time and the temperature of the electrolytic bath, it is possible to prepare deposits with various morphologies. Thick deposits with well-faceted particles of Fe 3O4 are produced when long deposition times are used; thin and shapeless deposits are formed after shorter electrolysis times. A screening study shows Fe3O4 films prepared at 50°C under -5 mA cm-2 for 40 s give the best electrochemical performance towards Li, namely with a sustained reversible capacity for over 50 cycles and outstanding rate capability even after 50 repeated charge-discharge sequences. Electrodeposition techniques provide an alternative efficient way to configure high-performance conversion electrodes based on carbon-free binary oxides. © 2006 WILEY-VCH Verlag GmbH & Co. KGaA.