Lithium ionic diffusion in lithium cobalt ozides prepared by mechanical milling
Li+ionic diffusion in LiCoO2 exposed to ball milling was studied by XRD, complex resistivity, and NMR. Angular frequency dependence of the complex resistivity is analyzed by using a Debye-type relaxation model. The Li+ion hopping time becomes fast by exposing to short-time milling, whereas it becomes slow by exposing to long-time milling. The activation energy of the Li+ionic diffusion in milled LiCoO2 samples varies from 0.29 to 0.36 eV as the milling time increases up to 60 h. These results suggest that exposure to appropriate milling time enhances the Li+ionic diffusion but the excessive milling is disadvantageous for the Li+ionic diffusion. In addition, an increase in the line width of 7Li NMR spectrum with increasing milling time is discussed in connection with the line width arising from magnetic cobalt ions.
Lithium ionic diffusion Lithium transition-metal ozides Mechanical milling NMR Complez resistivity
Koichi Nakamura Hiroshi Hirano Daisuke Nishioka Yoshitaka Michihiro Toshihiro Moriga
Institute of Technology and Science, The University of Tokushima, 2-1 Minami-Josanjima-Cho, Tokushima 770-8506, Japan
国际会议
The 16th International Conference on Solid State Ionics(第十六届国际固态离子学会议)
上海
英文
1806-1809
2007-07-01（万方平台首次上网日期，不代表论文的发表时间）