[1] Huazhong Univ Sci & Technol, Key Lab Mat Chem Energy Convers & Storage, Minist Educ, Hubei Key Lab Mat Chem & Serv Failure,Sch Chem &, Wuhan 430074, Peoples R China
[2] Chinese Acad Sci, Beijing Natl Lab Condensed Matter Phys, Inst Phys, Beijing 100190, Peoples R China
[3] Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA
[4] Brookhaven Natl Lab, Ctr Funct Nanomat, Upton, NY 11973 USA