Publication
Title
$\beta-Na_{1.7}IrO_{3}$ : a tridimensional Na-Ion insertion material with a redox active oxygen network
Author
Abstract
 The revival of the Na-ion battery concept has prompted an intense search for new high capacity Na-based positive electrodes. Recently, emphasis has been placed on manipulating Na-based layered compounds to trigger the participation of the anionic network. We further explored this direction and show the feasibility of achieving anionic-redox activity in three-dimensional Nabased compounds. A new 3D beta-Na1.7IrO3 phase was synthesized in a two-step process, which involves first the electrochemical removal of Li from beta-Li2IrO3 to produce beta-IrO3, which is subsequently reduced by electrochemical Na insertion. We show that beta-Na1.7IrO3 can reversibly uptake nearly 1.3 Na+ per formula unit through an uneven voltage profile characterized by the presence of four plateaus related to structural transitions. Surprisingly, the beta-Na1.7IrO3 phase was found to be stable up to 600 degrees C, while it could not be directly synthesized via conventional synthetic methods. Although these Na-based iridate phases are of limited practical interest, they help to understand how introducing highly polarizable guest ions (Na+) into host rocksalt-derived oxide structures affects the anionic redox mechanism.
Language
English
Source (journal)
Chemistry of materials / American Chemical Society. - Washington, D.C., 1989, currens
Publication
Washington, D.C. : 2018
ISSN
0897-4756 [print]
1520-5002 [online]
Volume/pages
30 :10 (2018) , p. 3285-3293
ISI
000433403800014
Full text (Publisher's DOI)
Full text (open access)
Full text (publisher's version - intranet only)
UAntwerpen
 Faculty/Department Research group Project info ARPEMA: Anionic redox processes: A transformational approach for advanced energy materialsImproving the performance of rock salt type cathodes for Li-ion batteries through control of the transition metal cation migration using redox reactions of the oxygen sublattice and Li-conductive coatings. Publication type Subject Affiliation Publications with a UAntwerp address