1. Eduard Zintl Institute for Inorganic and Physical Chemistry Technical University of Darmstadt 64287 Darmstadt Germany
2. Department of Materials and Earth Sciences Group of Dispersive Solids Technical University of Darmstadt 64287 Darmstadt Germany
3. Institute for Technical Chemistry and Environmental Chemistry Friedrich-Schiller-University Jena 07743 Jena Germany
4. EnBW Energie Baden-Württemberg AG Durlacher Allee 93 76131 Karlsruhe Germany