1. Department of Chemistry, Universität Bayreuth, Universitätsstrasse 30, 95447 Bayreuth, Germany
2. Bavarian Center for Battery Technology (BayBatt), Universität Bayreuth, Weiherstrasse 26, 95448 Bayreuth, Germany
3. Institut Laue-Langevin, Avenue des Martyrs, 38042 Grenoble Cedex 9, France