1. Chemistry Division School of Science and Technology University of Camerino Via S. Agostino 1 62032 Camerino Italy
2. Accumulator Material Research (ECM) Zentrum für Sonnenenergie-und Wasserstoff-Forschung Baden-Wüttemberg ZSW-Labor für Batterietechnologie (eLaB) Lise-Meitner-Str. 24 D-89081 Ulm Germany
3. present address: Institute for Applied Materials (IAM) Karlsruhe Institute of Technology (KIT) Hermann-von-Helmholtz-Platz 1 D-76344 Eggenstein-Leopoldshafen Germany