A high capacity thiospinel cathode for Mg batteries

Date Published
05/2016
Publication Type
Journal Article
Authors
DOI
10.1039/C6EE00724D
Abstract

Magnesium batteries are energy storage systems that potentially offer high energy density owing to their ability to employ magnesium metal as a negative electrode. Their development, however, has been thwarted by a paucity of functional positive electrode materials after the seminal discovery of the Mo6S8 Chevrel phase over 15 years ago. Herein, we report the second such material – a thiospinel – and demonstrate fully reversible Mg2+electrochemical cycling vs. a Mg anode, which is complemented by diffraction and first principles calculations. The capacity approaches 80% of the theoretical value at a practical rate (C/5) at 60 °C, and yields a specific energy of 230 Wh kg−1, twice that of the Chevrel benchmark. Our results emphasize the advantage in employing “soft” anions to achieve practical divalent cation mobility.

Journal
Energy & Environmental Science
Volume
9
Year of Publication
2016
Issue
7
Pagination
2273 - 2277
ISSN Number
1754-5692
Short Title
Energy Environ. Sci.
Refereed Designation
Refereed
Organizations
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