Lithium ion pathways in LiFePO4 and related olivines

Determining ion transport pathways as regions of low bond valence mismatch represents a simple, reliable way of characterizing ion transport pathways in local structure models, provided that the local structure model captures the essential structural features. The examples of LiFePO₄ and other olivine-type mixed conductors discussed here demonstrate the impact of structural disorder on the ion transport pathway and mechanism. The effect of Li′_Fe antisite defects on the transition from one- to two-dimensional conduction pathway dimensionality as well the possibility of heterogeneous doping of LiFePO₄ by a lithium phosphate glass surface layer are discussed in detail.