Enhanced Li-storage capability and cyclability of iron fluoride cathodes by non-equivalent cobalt doping

Theoretical calculation reveals that non-equivalent cobalt doping of 1% (in atomic ratio, at.) could lower the energy gap of cubic-phase FeF3 from 4.27 eV to 0.27 eV, and fundamental change the charge density distribution around. Enlightened by these results, the electrochemical properties of iron fluoride cathode that limited by the intrinsic sluggish kinetics and poor electronic conductivity would be significantly improved by non-equivalent doping. Exemplified by porous FeF3 nanocages prepared by pyrolysis of fast crystallized (NH4)(3)FeF6 (3NH(4)F center dot FeF3) double salts, enhanced Li-storage capability and cyclability were demonstrated by non-equivalent cobalt doping due to defect-related modification of electron-/ion-conductivity and increase of active sites. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

Theoretical calculation shows that non-equivalent cobalt doping can significantly improve the electrochemical properties of iron fluoride cathode. This is achieved by modifying electron-/ion-conductivity and increasing active sites, leading to enhanced Li-storage capability and cyclability.