1. Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education) College of Physics Jilin University Changchun 130012 P. R. China
2. School of Physics Southeast University Nanjing 211189 P. R. China
3. Department of Materials Science and Engineering and Center of Super-Diamond and Advanced Films (COSDAF) City University of Hong Kong Kowloon 999077 Hong Kong SAR