Origin of electrochemical activity in nano-Li2MnO3; Stabilization via a 'point defect scaffold'

Sayle, T.X.T. and Caddeo, F. and Monama, N.O. and Kgatwane, K.M. and Ngoepe, P.E. and Sayle, D.C. (2015) Origin of electrochemical activity in nano-Li2MnO3; Stabilization via a 'point defect scaffold'. Nanoscale, 7 (3). pp. 1167-1180. ISSN 20403364 (ISSN). (doi:https://doi.org/10.1039/c4nr05551a) (Full text available)

Abstract

Molecular dynamics (MD) simulations of the charging of Li2MnO3 reveal that the reason nanocrystalline-Li2MnO3 is electrochemically active, in contrast to the parent bulk-Li2MnO3, is because in the nanomaterial the tunnels, in which the Li ions reside, are held apart by Mn ions, which act as a pseudo 'point defect scaffold'. The Li ions are then able to diffuse, via a vacancy driven mechanism, throughout the nanomaterial in all spatial dimensions while the 'Mn defect scaffold' maintains the structural integrity of the layered structure during charging. Our findings reveal that oxides, which comprise cation disorder, can be potential candidates for electrodes in rechargeable Li-ion batteries. Moreover, we propose that the concept of a 'point defect scaffold' might manifest as a more general phenomenon, which can be exploited to engineer, for example, two or three-dimensional strain within a host material and can be fine-tuned to optimize properties, such as ionic conductivity.

Item Type: Article
Additional information: Unmapped bibliographic data: LA - English [Field not mapped to EPrints] J2 - Nanoscale [Field not mapped to EPrints] AD - School of Physical Sciences, University of KentCanterbury, United Kingdom [Field not mapped to EPrints] AD - Materials Modelling Centre, University of Limpopo, Private Bag x1106Sovenga, South Africa [Field not mapped to EPrints] AD - Centre for High Performance Computing CSIR, 15 Lower Hope RdCape Town, South Africa [Field not mapped to EPrints] DB - Scopus [Field not mapped to EPrints]
Uncontrolled keywords: Charging (batteries), Defects, Ions, Lithium, Manganese, Manganese oxide, Molecular dynamics, Nanostructured materials, Point defects, Scaffolds, Cation disorder, Electrochemical activities, Layered Structures, Li-ion batteries, Molecular dynamics simulations, Nanocrystallines, Spatial dimension, Three-dimensional strains, Lithium batteries
Subjects: Q Science > QD Chemistry > QD478 Solid State Chemistry
Q Science > QD Chemistry
Divisions: Faculties > Sciences > School of Physical Sciences > Functional Materials Group
Depositing User: Dean Sayle
Date Deposited: 27 Jan 2015 16:17 UTC
Last Modified: 27 Feb 2015 15:28 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/46767 (The current URI for this page, for reference purposes)
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