Tin oxides as a negative electrode material for Mg-Ion batteries

Abstract In this study, SnO as a negative electrode material for Mg-ion batteries exhibits a larger capacity of 540 mA h g−1 at the first cycle than that of pure Sn, despite the lower 88 wt.% Sn content. XRD patterns and XPS spectra reveal alloying/de-alloying, with Sn formed by the reduction during the first charging. The greater capacity is attributed to the shorter Mg diffusion length in the resulting fine Sn particles. The MgO matrix played a role in maintaining the high capacity for more than 10 cycles by diminishing the Sn agglomeration.