A novel intercalation cathode material for sodium-based batteries

Abstract We propose NaFeZr 2 F 11 and NaFeTi 2 F 11 as novel materials for Na intercalation cathodes. The average sodium intercalation voltage for these compounds is about 4.0 V from first principles computations. The origin of this large voltage for a nominal Fe 2 + /Fe 3 + redox couple is proposed to be a combination of the fluorine “booster” effect, the inductive effect and the stiffness of the proposed structure upon desodiation.