1. State Key Laboratory of Silicon Materials School of Materials Science and Engineering Zhejiang University Hangzhou 310027 P. R. China
2. Key Laboratory of Advanced Materials and Applicationsfor Batteries of Zhejiang Province Hangzhou 310027 P. R. China
3. Institute of Physical Chemistry Zhejiang Normal University Jinhua 321004 P. R. China
4. School of Materials Science and Engineering Beijing University of Aeronautics and Astronautics Beijing 100191 P. R. China