화학공학소재연구정보센터
Journal of Physical Chemistry B, Vol.109, No.26, 12791-12794, 2005
Madelung-Buckingham model as applied to the prediction of voltage, crystal volume changes, and ordering phenomena in spinel-type cathodes for lithium batteries
Using a Madelung-Buckingham model, we study LixMn2O4 and its fluorine-substituted analogue to compute their voltages, lattice volume changes, and ordering phenomena during charge/discharge. The interactions included are the long-range Coulombic, short-range electron-electron repulsion, and the van der Waals. The voltage of the fluorine-substituted spinel is found to be slightly less than that of the unsubstituted. However, the former undergoes a greater crystal volume change than the latter during intercalation and de-intercalation. Investigations of lithium sublattice ordering in this system indicates that during intercalation lithium starts filling exclusively into one sublattice until x = 0.5, and only from x = 0.5 the other sublattice is filled up to x = 1. The models are compared with quantum ab initio and experimental results.