Fluorine compounds have high discharge voltage due to its highly ionic metal-ligand bonds. In them, perovskite-type metal trifluorides with corner sharing matrix have large bottlenecks of diffusion pathways for intercalants. iron trifluoride composites (FeF3-C) prepared by planetary ball milling with carbon showed reversible charge/discharge behavior not only for Li, but also for Na anodes. X-ray diffraction and Fe-57 Mossbauer spectroscopy were applied to characterize the electrochemical properties of FeF3 vs. Li and Na anodes. The cathode performances of the other commercially available transition metal trifluorides such as MF3 (M =Ti, V, Mn, Co) have been also investigated. (C) 2009 Elsevier B.V. All rights reserved.