Micro-Raman Spectroscopic Study on Layered Lithium Manganese Oxide and Its Delithiated/Relithiated Derivatives

Abstract

Micro-Raman spectroscopic analyses have been performed for the layered <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="ML1" overflow="scroll"> <mml:msub> <mml:mi mathvariant="normal">LiMnO</mml:mi> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msub> </mml:math> compound and its delithiated/relithiated derivatives in order to probe the effect of Li extraction/insertion on the local structure around manganese ion in this layered material. For this purpose, we have first tried to establish a spectroscopic measure for identifying the lithium manganates with closely related structures. From the detailed comparison among the Raman spectra of layered and spinel-structured lithium manganates, both phases can be easily differentiated from each other by using micro-Raman spectroscopy. Based on these experimental findings, we are able to conclude that the chemical or electrochemical deintercalation of lithium gives rise to the Mn migration into the interlayer lithium site, resulting in the creation of the spinel-like cation ordering. © 2001 The Electrochemical Society. All rights reserved.