四面体LiFeO2的合成及其作为可充电电池中的阴极的行为
A Robert Armstrong1, Daniel W Tee, Fabio La Mantia
1EaStCHEM, School of Chemistry, University of St. Andrews, St. Andrews, Fife, KY16 9ST, UK.
Journal of the American Chemical Society
|February 21, 2008
概括
第一个四面体协调铁 (III) 氧化铁 (LiFeO2) 储存120mAhg (-1) 电荷,但通过电解质反应和循环过程中的水损失转化为LiFe5O8.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 固态化学 固态化学
背景情况:
- 氧化铁 (LiFeO2) 是离子电池的新材料.
- 了解其电化学行为和降解途径对于电池开发至关重要.
研究的目的:
- 用四面体协调的Fe3+合成和描述LiFeO2.
- 为了研究LiFeO2.2的电荷储存能力和循环稳定性.
- 为了阐明 LiFeO2 在电化学循环过程中的转化机制.
主要方法:
- 合成的 LiFeO2.2. 的合成.
- 粉末X射线衍射 (PXRD). 粉末X射线衍射.
- 不同电化学质谱法 (DEMS).
- 电化学循环. 电化学循环.
- 热重力测量分析与质谱学 (TG-MS) 相结合.
主要成果:
- 合成了第一个具有四面体协调Fe3+的LiFeO2化合物.
- 该材料的电荷储存容量高达120 mAhg{-1) 在100 mAg{-1) 时.
- 在循环过程中,LiFeO2通过一种涉及氧气损失和与电解质反应的过程转化为缺陷旋转LiFe5O8,而不是O2进化.
结论:
- 转化机制涉及Li+/H+交换和H2O损失,导致LiFe5O8.8的形成.
- 这种转换限制了LiFeO2作为正电极材料的长期循环性.
- 需要进一步的研究来稳定LiFeO2或开发具有更好的循环性能的替代材料.
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