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影响因子：15.419

DOI码：10.1021/ja303225e

发表刊物：J. Am. Chem. Soc

关键字：RECHARGEABLE LITHIUM； BATTERIES；ENERGY-LOSS SPECTROSCOPY；AUGMENTED-WAVE METHOD；ELECTRICAL-CONDUCTIVITY；ABSORPTION-SPECTROSCOPY；MISCIBILITY GAP；LIFEPO4；ION；VISUALIZATION；LI-1-XFEPO4

摘要：Through soft X-ray absorption spectroscopy, hard X-ray Raman scattering, and theoretical simulations, we provide the most in-depth and systematic study of the phase transformation and (de)lithiation effect on electronic structure in LixFePO4 nanoparticles and single crystals. Soft X-ray reveals directly the valence states of Fe 3d electrons in the vicinity of Fermi level, which is sensitive to the local lattice distortion, but more importantly offers detailed information on the evolution of electronic states at different electrochemical stages. The soft X-ray spectra of LixFePO4 nanoparticles evolve vividly with the (de)lithiation level. The spectra fingerprint the (de)lithiation process with rich information on Li distribution, valency, spin states, and crystal field. The high resolution spectra reveal a subtle but critical deviation from two-phase transformation in our electrochemically prepared samples. In addition, we performed both first principles calculations and multiplet simulations of the spectra and quantitatively determined the 3d valence states that are completely redistributed through (de)lithiation. This electronic reconfiguration was further verified by the polarization-dependent spectra collected on LiFePO4 single crystals, especially along the lithium diffusion direction. The evolution of the 3d states is overall consistent with the local lattice distortion and provides a fundamental picture of the (de)lithiation effects on electronic structure in the LixFePO4 system.

合写作者：Jun Liu, Ruimin Qiao, Yan Yu, Hong Li, Liumin Suo, Yongsheng Hu, Yi-De Chuang, Guojiun Shu, Fangcheng Chou, Tsu-Chien Weng, Dennis Nordlund, Dimosthenis Sokaras, Yung Jui Wang, Hsin Lin, Bernardo Barbiellini, Arun Bansil, Xiangyun Song, Zhi Liu, Shishen Yan, Gao Liu, Shan Qiao, Thomas J. Richardson, David Prendergast, Zahid Hussain, Frank M. F. de Groot

第一作者：Xiaosong Liu

通讯作者：Wanli Yang

论文编号：13708-13715

卷号：134

期号：33

页面范围：3708-13715

ISSN号：0002-7863

是否译文：否

发表时间：2012-07-26

发布期刊链接：https://pubs.acs.org/doi/10.1021/ja303225e