Insights in the electronic structure and redox reaction energy in LiFePO4 battery material from an accurate Tran-Blaha modified Becke Johnson potential
2015 (English)In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 118, no 12, 125107Article in journal (Refereed) PublishedText
The main goals of this paper are to investigate the accuracy of the Tran-Blaha modified Becke Johnson (TB-mBJ) potential to predict the electronic structure of lithium iron phosphate and the related redox reaction energy with the lithium deintercalation process. The computed electronic structures show that the TB-mBJ method is able to partially localize Fe-3d electrons in LiFePO<inf>4</inf> and FePO<inf>4</inf> which usually is a problem for the generalized gradient approximation (GGA) due to the self interaction error. The energy band gap is also improved by the TB-mBJ calculations in comparison with the GGA results. It turned out, however, that the redox reaction energy evaluated by the TB-mBJ technique is not in good agreement with the measured one. It is speculated that this disagreement in the computed redox energy and the experimental value is due to the lack of a formal expression to evaluate the exchange and correlation energy. Therefore, the TB-mBJ is an efficient method to improve the prediction of the electronic structures coming form the standard GGA functional in LiFePO<inf>4</inf> and FePO<inf>4</inf>. However, it does not appear to have the same efficiency for evaluating the redox reaction energies for the investigated system.
Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2015. Vol. 118, no 12, 125107
Electric batteries, Electronic structure, Energy gap, Lithium alloys, Lithium compounds, Battery materials, Exchange and correlation, Experimental values, Formal expressions, Generalized gradient approximations, Lithium deintercalation, Lithium iron phosphates, Self-interaction error, Redox reactions
IdentifiersURN: urn:nbn:se:kth:diva-181147DOI: 10.1063/1.4932025ISI: 000362565800058ScopusID: 2-s2.0-84942870629OAI: oai:DiVA.org:kth-181147DiVA: diva2:900226
QC 201602032016-02-032016-01-292016-02-03Bibliographically approved