1. College of Materials Science and Engineering, Kunming University of Science and Technology, Kunming 650093, P. R. China
2. Engineering Research Center of New Energy Storage Devices and Applications, Chongqing University of Arts and Sciences, Chongqing 402160, P. R. China
3. College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, P. R. China
4. University Research Facility in Materials Characterization and Device Fabrication, The Hong Kong Polytechnic University, Hong Kong, 999077P. R. China
5. Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650093, P. R. China
6. Kunming Institute of Precious Metals, Kunming 650093, P. R. China