The summary of his thesis "Antifluorite-type oxides as positive electrodes for Li/Na-ion batteries";
As we transition to a fully electrified society, it is clear that batteries are essential pieces in the overall energy puzzle. While current battery chemistries have gone far in revolutionising electric mobility, improved batteries are still needed for more demanding applications. At the same time, highly concentrated supply chains and increasing geopolitical tensions pose potential risks to the pace of electrification. As such, new battery chemistries that could address these issues are desirable. One interesting avenue of research is the study of Li/Na-rich electrode materials that promise higher capacities than current chemistries due to an additional redox contribution from the anionic framework.
This work explores one such class of materials: the antifluorite-type oxides. The series Li5+xFe1-xCoxO4 is synthesised and subjected to structural and magnetic characterisation. A selection of these materials (x = 0.0, 0.5, 1.0) are further tested as positive electrode materials in Li-ion batteries in which the chemical and structural evolution of the materials is tracked through operando experiments during initial charging over two distinct potential plateaus, and subsequent discharge following termination after each of these plateaus.
The Na-based analogue Na5FeO4 is also investigated using density functional theory to assess the suitability as a positive electrode material in Na-ion batteries, in which a potential reaction pathway that would allow reversible cycling is identified.
Congratulations to Dr. Rasmus Vester Thørgersen for completing his disputation and earning his degree of Philosophiae Doctor!
Adjudication committee
▫️Professor Dorthe Ravnsbæk
Intitut for Kemi, Århus Universitet, Denmark
▫️Professor Daniel Bandell
Department of Chemistry, Uppsala Universitet, Sweden
▫️Professor Reidar Haugsrud
Department of Chemistry, University of Oslo, Norway
Supervisors
Professor Helmer Fjellvåg & Associate Professor Vajeeston Ponniah
Chair of defence
Professor Steven Wilson
See more at the announcement