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Chemical speciation and mapping of the Si in Si doped LFP ingot with synchrotron radiation technique
Author(s) -
Norouzi Banis Mohammad,
Wang Zhiqiang,
Rousselot Steeve,
Liu Yulong,
Hu Yongfeng,
TalebiEsfandarani Majid,
Bibienne Thomas,
Gauthier Michel,
Li Ruying,
Liang Guoxian,
Dollé Mickaël,
Sauriol Pierre,
Sham TsunKong,
Sun Xueliang
Publication year - 2019
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.23430
Subject(s) - ingot , doping , materials science , impurity , dopant , analytical chemistry (journal) , absorption spectroscopy , amorphous solid , silicon , absorption (acoustics) , spectroscopy , x ray absorption fine structure , x ray absorption spectroscopy , chemistry , crystallography , optoelectronics , metallurgy , optics , physics , organic chemistry , alloy , chromatography , quantum mechanics , composite material
Development of LiFePO 4 cathode material with high cycle life through Si doping (substituting Si at P sites of LiFePO 4 ) has shown that small changes to the structure of LiFePO 4 can significantly affect the performance of Li ion batteries. However, determining the nature of elemental doping and their effects on the electronic and atomic structure of LiFePO 4 remains challenging. Here we present x‐ray absorption spectroscopy and x‐ray fluorescence mapping as ideal characterization methods for understanding the effect of Si doped LiFePO 4 prepared using a melt‐synthesis process. x‐ray absorption spectra of silicon doped LiFePO 4 indicate subtle changes in the local structure surrounding the dopants compared to SiO 2 and amorphous glass phases formed as impurities in Si containing undoped samples. The study of Fe and P K‐edges x‐ray absorption spectra illustrates the effect of Si in the LiFePO 4 structure in doped and impurity containing samples. Utilizing x‐ray absorption spectroscopy, in conjunction with x‐ray fluorescence mapping, has enabled a better overview of the non‐uniform nature of prepared ingot samples. These results highlight the power of x‐ray absorption spectroscopy as a tool for better understanding the structure of modified LiFePO 4 and subsequently designing materials for Li ion batteries.