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.
BT - Energy & Environmental Science DA - 05/2016 DO - 10.1039/C6EE00724D IS - 7 LA - eng N2 -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.
PY - 2016 SP - 2273 EP - 2277 ST - Energy Environ. Sci. T2 - Energy & Environmental Science TI - A high capacity thiospinel cathode for Mg batteries VL - 9 SN - 1754-5692 ER -