SnSb Carbon Composite Anode in a SnSb_C/NaNi1/3Mn1/3Fe1/3O2 Na-Ion Battery

Tin and antimony metals were high-energy ball-milled with carbon in order to create a SnSb_C alloy carbon composite worthy of cycling as a high-capacity 500 mAh/g anode in a full cell Na-ion battery. In the cell, coupled with a cathode consisting of a layered transition metal oxide cathode NaNi1/3Mn1/3Fe1/3O2, was cycled for over fifty cycles with near 100% coulombic efficiency, yielding a resultant gravimetric energy density of 145 Wh/kg (based on electrode material only), and an even better volumetric energy density of 215 Wh/L due to the high density inherent in the SnSb_C anode. In situ synchrotron X-ray diffraction measurements indicate a progressive amorphization of the SnSb during sodiation without any observable binary sodium-tin or sodium-antimony alloy phase formation. The electrochemically active amorphous phase remains present during desodiation