%0 Journal Article
%A Xiaoqi Sun
%A Patrick Bonnick
%A Victor Duffort
%A Miao Liu
%A Ziqin Rong
%A Kristin A Persson
%A Gerbrand Ceder
%A Linda F Nazar
%B Energy & Environmental Science
%D 2016
%G eng
%N 7
%P 2273 - 2277
%R 10.1039/C6EE00724D
%T A high capacity thiospinel cathode for Mg batteries
%V 9
%8 05/2016
%! Energy Environ. Sci.
%X <p><span>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 Mo</span><small><span>6</span></small><span>S</span><small><span>8</span></small><span>&nbsp;Chevrel phase over 15 years ago. Herein, we report the second such material – a thiospinel – and demonstrate fully reversible Mg</span><small><span>2+</span></small><span>electrochemical cycling&nbsp;</span><em>vs.</em><span>&nbsp;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</span><small><span>−1</span></small><span>, twice that of the Chevrel benchmark. Our results emphasize the advantage in employing “soft” anions to achieve practical divalent cation mobility.</span></p>