1. Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), 3 Research Link, Singapore 117602
2. School of Materials Science and Engineering, The University of New South Wales, Sydney, NSW 2052, Australia
3. Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics, Jilin University, Changchun 130012, China
4. Department of Electrical Engineering and Information Technology, University of Duisburg-Essen, 47057 Duisburg, Germany