In:
Materials for Renewable and Sustainable Energy, Springer Science and Business Media LLC, Vol. 9, No. 1 ( 2020-03)
Abstract:
We examined the electronic property of Sb-doped Na 0.785 CoO 2 using density functional calculations based on GGA+ U formalism. We demonstrated that Sb dopants were the most stable when replacing Co ions within the complex Na 0.875 CoO 2 lattice structure. We also showed that the Sb Co dopants adopted the + 5 oxidation state introducing two electrons into the host Na 0.875 CoO 2 compound. The newly introduced electrons recombined with holes that were borne on Co 4+ sites that had been created by sodium vacancies. The elimination of Co 4+ species, in turn, rendered Na 0.875 (Co 0.9375 Sb 0.0625 )O 2 non-magnetic and diminished the compound’s thermoelectric effect. Furthermore, the Sb Co dopants tended to aggregate with the Na vacancies keeping a minimum distance. The conclusions drawn here can be generalised to other highly oxidised dopants in Na x CoO 2 that replace a Co.
Type of Medium:
Online Resource
ISSN:
2194-1459
,
2194-1467
DOI:
10.1007/s40243-020-0165-9
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2020
detail.hit.zdb_id:
2705704-5
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