In Situ X-Ray Absorption Spectroscopy Studies of Nanosized LiAl0.15Mn1.85 O 4 Cathode Material in an Aqueous Solution

Abstract

We have performed in situ Mn K-edge X-ray absorption spectroscopy (XAS) studies on nanosized cathode material at various charging and discharging potentials in an aqueous solution (9.0 M The associated changes in the electronic and local atomic structures were investigated during the course of charging and discharging. The B1 and B2 peaks appeared in the Mn K-edge X-ray absorption near-edge structure spectra of were due to pronounced multiple scattering effect. Two types of bonds, namely and were observed in the first coordination shell. It was found that the and the second shell Mn-Mn/Al bond distances as well as the Debye-Waller factors decrease on charging and increase on discharging. In contrast, the bonds show an elongation on charging and contraction on discharging. The Debye-Waller factor of does not change significantly during both charging and discharging. Thus, we infer that the ordering of octahedra is mainly due to the contribution from bonds. © 2003 The Electrochemical Society. All rights reserved.