1. Division
of Physics and Applied Physics, School of Physical and Mathematical
Sciences, Nanyang Technological University, Singapore 637371, Singapore
2. State Key Laboratory of Silicon Materials, Key Laboratory of Advanced Materials and
Applications for Batteries of Zhejiang Province, and Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
3. School
of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore