Changes in electronic structure upon lithium insertion into Fe2(SO4)3 and Fe2(MoO4)3 investigated by X-ray absorption spectroscopy
Changes in electronic structure upon lithium insertion into Fe2(SO4)3 and Fe2(MoO4)3 investigated by X-ray absorption spectroscopy
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DOI：
10.1021/jp065802g
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发表时间：
2007-02-15
影响因子：
3.3
通讯作者：
Uchimoto, Yoshiharu
中科院分区：
文献类型：
--
作者：
Shirakawa, Junichi;Nakayama, Masanobu;Uchimoto, Yoshiharu
用X射线吸收光谱（XAS）研究了具有NASICON型结构的菱方铁Fe-2（SO 4）（3）和单斜铁Fe-2（MoO 4）（3）在电化学嵌锂过程中电子结构的变化. Fe的K边、L-III边和L-II边XAS表明，两种样品的Fe d电子重排或Fe d-O p键的再杂化都伴随着Fe离子在Li插入时的还原，Fe-2（SO 4）（3）的光谱发生了较大的变化。此外，还用O K-边和S K-边或Mo L-III-边XAS研究了Li插入后聚阴离子单元XO_（42-）（X = S或Mo）电子结构的变化.结果表明，Fe-2（MoO_4）（3）中氧的电子结构发生了明显的变化，而Fe-2（SO_4）（3）中氧的电子结构没有发生明显的变化。
Changes in electronic structure upon electrochemical lithium insertion into two iron compounds, namely, rhombohedral Fe-2(SO4)(3) with a NASICON-type structure and monoclinic Fe-2(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 Fe-2(SO4)(3). In addition, the changes in the electronic structure of the polyanion units XO42- (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 Fe-2(MoO4)(3), while no significant change was observed in Fe-2(SO4)(3).