Identifying Different States of Lithiation of Li4Ti5O12 Spinel by Energy-Dispersive Inelastic X-Ray Scattering (EDIXS) Spectroscopy

J. J. LEANI; J. I. ROBLEDO; S. CHAUQUE; O. CÁMARA; F. Y. OLIVA ; H. J. SÁNCHEZ

Conferencia; 2020 Express Conference on the Physics of Materials and its application in Energy and Environment; 2020

During the last two decades, the compound Li4Ti5O12 (also known as LTO) has been investigated as an alternative negative electrode material for lithium ion batteries (LIBs), which are being used as energy storage devices in stationary systems as well as for electric vehicles due to their many interesting features. LTO compound has shown a remarkable Li-ion intercalation/de-intercalation reversibility, demonstrating also zero-strain volume change during the cycling process, with the addition of a notable safety performance. Furthermore, LTO has a high voltage plateau in comparison with other negative material candidates, helping to avoid the formation of metallic lithium during the charging process. Due to its performance and potential applications in LIBs, a deep knowledge regarding the behavior of this LTO compound is of high interest. In this work, Energy-Dispersive Resonant Inelastic X-ray Scattering (EDIXS) is used to fulfill this need. In addition, XANES measurements were carried out as complementary methodology. The results show that EDIXS can differentiate LTO chemical compounds (lithiated and de-lithiated) and that it is a reliable tool to perform chemical speciation analysis on this kind of samples. In addition, the results confirm theoretical predictions regarding the composition of the different oxidation states of titanium associated to different states of lithiation of the LTO-spinel.