1. Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), & States Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, P. R. China
2. Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
3. College of Science, Guilin University of Technology, Guilin 541004, China
4. A.J. Drexel Nanomaterials Institute and Department of Materials Science and Engineering, Drexel University, Philadelphia, Pennsylvania 19104, United States