Predicting electrochemical properties and ionic diffusion in Na2+2xMn2-x(SO4)(3): crafting a promising high voltage cathode material
2016 (English)In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 4, no 2, 451-457 p.Article in journal (Refereed) PublishedText
Sodium ion batteries have emerged as a good alternative to lithium based systems due to their low cost of production. In this scenario, the search for higher voltage, sodium cathodes results in a new promising alluaudite structure Na2+2xMn2-x(SO4)(3). The structural, electronic and Na diffusion properties along with defects have been reported in this investigation within the framework of density functional theory. A band gap of 3.61 eV has been computed and the average deintercalation potential is determined to be 4.11 V vs. Na/Na+. A low concentration of anti-site defects is predicted due to their high formation energy. The biggest issue for the ionic diffusion in the Na2+2xMn2-x(SO4)(3) crystal structure is revealed to be the effect of Mn vacancies increasing the activation energy of Na+ ions that hop along the  equilibrium positions. This effect leads to activation energies of almost the same high values for the ionic hop through the  direction characterizing a 2D like ionic diffusion mechanism in this system.
Place, publisher, year, edition, pages
Royal Society of Chemistry, 2016. Vol. 4, no 2, 451-457 p.
IdentifiersURN: urn:nbn:se:kth:diva-180972DOI: 10.1039/c5ta08114aISI: 000367272800014ScopusID: 2-s2.0-84951768867OAI: oai:DiVA.org:kth-180972DiVA: diva2:898590
QC 201601282016-01-282016-01-262016-01-29Bibliographically approved