Accessibility navigation


Lithium and oxygen adsorption at the b-MnO2 (110) surface

Mellan, T. A., Maenetja, K. P., Ngoepe, P. E., Woodley, S. M., Catlow, C.R. A. and Grau-Crespo, R. (2013) Lithium and oxygen adsorption at the b-MnO2 (110) surface. Journal of Materials Chemistry A, 1 (47). pp. 14879-14887. ISSN 0959-9428

[img]
Preview
Text - Published Version
· Available under License Creative Commons Attribution.
· Please see our End User Agreement before downloading.

2MB

It is advisable to refer to the publisher's version if you intend to cite from this work. See Guidance on citing.

To link to this item DOI: 10.1039/c3ta13559d

Abstract/Summary

The adsorption and co-adsorption of lithium and oxygen at the surface of rutile-like manganese dioxide(b-MnO2), which are important in the context of Li–air batteries, are investigated using density functional theory. In the absence of lithium, the most stable surface of b-MnO2, the (110), adsorbs oxygen in the form of peroxo groups bridging between two manganese cations. Conversely, in the absence of excess oxygen, lithium atoms adsorb on the (110) surface at two different sites, which are both tricoordinated to surface oxygen anions, and the adsorption always involves the transfer of one electron from the adatom to one of the five-coordinated manganese cations at the surface, creating (formally) Li+ and Mn3+ species. The co-adsorption of lithium and oxygen leads to the formation of a surface oxide, involving the dissociation of the O2 molecule, where the O adatoms saturate the coordination of surface Mn cations and also bind to the Li adatoms. This process is energetically more favourable than the formation of gas-phase lithium peroxide (Li2O2) monomers, but less favourable than the formation of Li2O2 bulk. These results suggest that the presence of b-MnO2 in the cathode of a nonaqueous Li–O2 battery lowers the energy for the initial reduction of oxygen during cell discharge.

Item Type:Article
Refereed:Yes
Divisions:Interdisciplinary centres and themes > Chemical Analysis Facility (CAF)
Faculty of Life Sciences > School of Chemistry, Food and Pharmacy > Department of Chemistry
ID Code:35785
Publisher:Royal Society of Chemistry

Downloads

Downloads per month over past year

University Staff: Request a correction | Centaur Editors: Update this record

Page navigation