电化学嵌锂γ—Li_xFe_2O_3的晶体结构

CRYSTAL STRUCTURE OF γ-Li_xFe_2O_3 WITH ELECTROCHEMICAL INSERTION OF Li

本文以Mossbauer谱学为主,辅以X射线衍射、XPS及电化学方法研究了电化学嵌锂γ-Li_xFe_2O_3的晶体结构。结果表明,以较小电流密度嵌锂时,晶体结构保持原来的尖晶石型;当以较大电流密度嵌锂或热激活时,由于Li^+的运动加剧,部分晶体结构转变为类似于氧化亚铁的面心立方结构。文中揭示了Li^+嵌入过程中的跃迁通道。讨论了Li^+的极限嵌入量。

Crystal structure of γ-Li_xFe_2O_3, inserted Li electrochemically, was studied by Mossbauer spectroscopy together with X-ray diffraction, XPS and electrochemical method. On the insertion of Li with low current density, the crystal structure is keeping original spinel; while with higher current desity or by thermal activation, owing to violent movement of Li^+ ions, part of crystal structure transforms into rock type similar to face—centered cubic structure of ferrous oxide. The transition channel during insertion of Li and limitation of Li^+ ions to be inserted were discussed.