Structural changes (degradation) of oxysulfide LiAl0.24Mn1.76O3.98S0.02 spinel on high temperature cycling

Abstract

The structural integrity of the oxysulfide material, LiAl0.24Mn1.76O3.98S0.02 before and after the charge-discharge cycling at high temperature was studied by X-ray diffraction and high-resolution transmission electron microscopy. The rock salt phase Li2MnO3 which is associated with the capacity loss has been detected at the surface of the oxysulfide particles in the electrode cycled in 4 V region at 80℃. The small structural degradation of the new oxysufide material could be responsible for the excellent cycleability of the oxysufide spinel at high temperature over the 4 V region.