Scientific Achievement
Highlights the specific importance of the use of more accurate hybrid DFT functionals when exploring the diffusion of Mg ions within α-MoO3, a potential cathode material for multivalent ions. Recommends using computationally more demanding but likely more accurate hybrid DFT in future studies of ion diffusion in transition metal oxide cathodes.
Significance and Impact
Computational materials scientists have only recently begun to explore the importance of exact-exchange hybrid DFT approaches to modeling transition metal oxides – as an alternative to the widely applied DFT+U approach. This work highlights the importance of hybrid functionals for modeling equilibrium structure in addition to the energetics of ion diffusion pathways within such materials.
Research Details
- Hybrid DFT produces a more ionic charge density within α-MoO3 (as expected).
- Cheaper, semi-local DFT calculations indicate approximately isotropic diffusion of Mg ions within α-MoO3, whereas hybrid DFT predicts significantly anisotropic diffusion, favoring diffusion along layer surfaces.
- Continued development of computationally more efficient hybrid DFT implementations matched with emergent supercomputing architectures should be encouraged.
