Crystallographic-shear phases of niobium oxide have shown unprecedented high-rate performance as high-voltage anodes for lithium-ion batteries. The electronic structure, lithium insertion mechanism, and lithium dynamics of these compounds remain relatively unexplored, largely due to their novelty and complexity. I will present our recent work on the electronic structure and lithium transport mechanism of crystallographic shear phases in the Wadsley-Roth family, including mixed-metal TiO2-Nb2O5, and WO3-Nb2O5 phases. These compounds feature blocks of niobium-oxygen octahedra as structural units, and we show that this block structure leads to a coexistence of flat and dispersive energy bands, corresponding to localized and delocalized electronic states. Our work has explored interesting electron localisation-delocalisation transitions on n-type doping in the niobium suboxides, and provides a unified mechanistic picture for the structural changes in the entire family of crystallographic shear phases.

I endeavour to make the presentation interesting for both an electronic structure theory, and a lithium-ion battery perspective.