1. Helmholtz Institute Ulm for Electrochemical Energy Storage (HIU); Helmholtzstrasse 11 89081 Ulm Germany
2. Institute of Nanotechnology; Karlsruhe Institute of Technology (KIT); P.O. Box 3640 76021 Karlsruhe Germany
3. Institute of Surface Chemistry and Catalysis; Ulm University; Albert-Einstein-Allee 47 89081 Ulm Germany
4. Joint Research Laboratory Nanomaterials, University of Technology; Jovanka-Bontschits-Strasse 2 64287 Darmstadt Germany