Abstract:
Lithium antimony oxide, Li3SbO4, is a candidate anode material for rechargeable lithium ion
batteries. Static atomistic scale simulations based on the classical pair potentials are
employed to provide insights into the defect chemistry, doping behaviour and lithium
diffusion paths in Li3SbO4. Here we show that, Li Frenkel is the dominant intrinsic defect
process and the activation energy of Li diffusion is very low (0.21eV) suggesting that very
high Li conduction is expected in this material. In particular, long range lithium diffusion
paths via vacancy mechanism were constructed and it is confirmed that the lowest
activation energy migration path is along the bc-axis plane with a zig-zag pattern. The
calculations further suggest that cation anti-site defects, in which Li and Sb exchange their
atomic positions, would not be observed with significant intrinsic concentration at
operating temperatures. Subvalent doping by Si on the Sb site is energetically favourable
suggesting that this efficient way to increase the Li content in Li3SbO4 should be stimulated
experimentally. The electronic structure calculations based on the density functional theory
(DFT) show that introduction of tetravalent dopants will not alter the band-gap
significantly.
