TITLE:
Structure Refinement of Mn-Substituted LiMnxFe1-xPO4
AUTHORS:
Masakazu Togo, Atsushi Nakahira
KEYWORDS:
Lithium Ion Battery, Olivine Material, Local Structure, Mn Substitution
JOURNAL NAME:
Materials Sciences and Applications,
Vol.9 No.6,
May
31,
2018
ABSTRACT: For Mn substituted LiMnxFe1-xPO4 synthesized by
hydrothermal process, the structural differences caused by Mn substitution were
characterized by SEM, ICP, XRD, XAFS, and FT-IR. In this study, by using XAFS
advantageous to the atomic selectivity, the local structure of MeO6 octahedral was
investigated. From
ICP, Mn composition in the products was similar to Mn addition amount, and the
peak shifts of XRD patterns with increasing Mn addition were observed.
The lattice constants refined by Rietveld analysis were a = 1.0338 ± 5 nm, b = 0.5995 ± 4 nm and c = 0.4696 ± 1 nm in LiFePO4,
and it was expanded linearly with increasing
Mn addition. Fe-O bond distance, which was calculated by curve fitting
of the radius distribution function of LiMnxFe1-xPO4, was 0.208 nm
smaller than 0.214 nm of
Mn-O bond. In addition, MeO6 octahedral expansion was affected to PO4 vibrational structure from FT-IR spectra.