通过X射线吸收光谱研究锂插入Fe2(SO4)3和Fe2(MoO4)3时的电子结构变化。

Changes in electronic structure upon lithium insertion into Fe2(SO4)3 and Fe2(MoO4)3 investigated by X-ray absorption spectroscopy.

作者信息

Shirakawa Junichi, Nakayama Masanobu, Wakihara Masataka, Uchimoto Yoshiharu

机构信息

Department of Applied Chemistry, Tokyo Institute of Technology, Tokyo 152-8552, Japan.

出版信息

J Phys Chem B. 2007 Feb 15;111(6):1424-30. doi: 10.1021/jp065802g. Epub 2007 Jan 24.

DOI:10.1021/jp065802g

PMID:17249717

Abstract

Changes in electronic structure upon electrochemical lithium insertion into two iron compounds, namely, rhombohedral Fe2(SO4)3 with a NASICON-type structure and monoclinic Fe2(MoO4)3, were investigated using X-ray absorption spectroscopy (XAS). Fe K-edge and L(III)- and L(II)-edge XAS revealed that the rearrangement of Fe d electrons or rehybridization of Fe d-O p bonding took place accompanied by the reduction of Fe ions upon Li insertion for both samples and that a larger change in spectra was observed in Fe2(SO4)3. In addition, the changes in the electronic structure of the polyanion units XO4(2-) (X = S or Mo) after Li insertion were also investigated by O K-edge and S K-edge or Mo L(III)-edge XAS. The results indicated that the electronic structure around oxygen markedly changed in Fe2(MoO4)3, while no significant change was observed in Fe2(SO4)3.

摘要

利用X射线吸收光谱（XAS）研究了电化学锂插入两种铁化合物（即具有NASICON型结构的菱面体Fe2(SO4)3和单斜晶系Fe2(MoO4)3）时电子结构的变化。Fe K边以及L(III)边和L(II)边XAS表明，对于两个样品，在锂插入时Fe d电子的重排或Fe d-O p键的重新杂化伴随着Fe离子的还原而发生，并且在Fe2(SO4)3中观察到更大的光谱变化。此外，还通过O K边和S K边或Mo L(III)边XAS研究了锂插入后多阴离子单元XO4(2-)（X = S或Mo）的电子结构变化。结果表明，Fe2(MoO4)3中氧周围的电子结构发生了显著变化，而在Fe2(SO4)3中未观察到明显变化。