1. Helmholtz Institute Ulm (HIU) Electrochemical Energy Storage, Helmholtzstrasse 11, D-89081 Ulm, Germany
2. Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), P.O. Box 3640, D-76021 Karlsruhe, Germany
3. Institute of Surface Chemistry and Catalysis, Ulm University, Albert-Einstein-Allee 47, D-89081 Ulm, Germany
4. Materials Science & Engineering Program and Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, United States
5. Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), CNRS, Université de Strasbourg, 23 rue du Loess, BP 43, F-67034 Strasbourg Cedex 2, France