[1] Chinese Acad Sci, Inst Phys, Lab Solid State Ion, Beijing 100190, Peoples R China
[2] Univ Wollongong, Inst Superconducting & Elect Mat, Wollongong, NSW 2252, Australia
[3] Beijing Inst Technol, Sch Chem Engn & Environm, Beijing 100081, Peoples R China
[4] Chonnam Natl Univ, Sch Mat Sci & Engn, Gwanju 500757, South Korea