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 Li(x)()Mn(2)O(4) 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.
Sherwood
Daniel
D
Modeling and Simulation Group, Central Electrochemical Research Institute, Karaikudi 630006, India.
Ragavendran
K
K
Emmanuel
Bosco
B