Tavorite-FeSO4F as a potential cathode material for Mg ion batteries: a first principles calculation.

The electrochemical and Mg ion diffusion properties of tavorite-Mg0.5FeSO4F were studied by using first principles calculations. A discharge voltage of about 2.52 V versus Mg/Mg(2+) corresponding to the redox couples of Fe(3+)/Fe(2+) was predicted for tavorite-Mg0.5FeSO4F, and the experimental diffusion coefficient for the Mg-vacancy in Mg0.5-xFeSO4F is expected to be of the same order of magnitude as that of the Li-vacancy in Li1-xFeSO4F.