Controlled processing of carefully designed Fe3O4/MgO heterostructures allowed identification of the Mg2+ diffusion pathways, reaction intermediates, and the key role of the anion in these energy-relevant systems.
Significance and Impact
Understanding Mg2+ diffusion in spinel structured oxides like Fe3O4 may provide design principles useful in the synthesis of next-generation cathode materials for new types of ion batteries.
- Thermal annealing operated as an alternative to battery cycling allowed precise control over conditions to observe cation diffusion in an Fe3O4/MgO system.
- The presence of O2, acting as excess anion, strongly affected cation diffusion and influenced the final phase of the material. Without O2, the magnesium cannot freely diffuse throughout the Fe3O4 layer.