Local structure and defect chemistry of substituted lithium manganate spinels: X-ray absorption and computer simulation studies

The charge distributions and effects on local structure resulting from substitution of Mn by Ti, Cr, Co and Ga in LiMn2O4 are determined by X-ray absorption spectroscopy. Atomistic simulation methods are used to obtain additional insights into local structure and to calculate the energetics of lithium disorder and migration in lattices containing these substitutional ions or Li on octahedral Mn sites. The formation of protonic species in spinel lithium manganates is discussed in relation to a tetrahedral–octahedral vacancy pair model.