1. 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 P. R. China
2. State Key Laboratory of Marine Resource Utilization in South China Sea Hainan University Haikou 570228 P. R. China
3. Institute of Physics Chinese Academy of Sciences Beijing 100190 China
4. MOE of the Key Laboratory of Bioinorganic and Synthetic Chemistry KLGHEI of Environment and Energy Chemistry School of Chemistry Sun Yat‐sen University Guangzhou 510275 China
5. Ames Laboratory U. S. Department of Energy and Department of Physics and Astronomy Iowa State University Ames IA 50011 USA