Electronic localization and bad-metallicity in pure and electron-doped troilite: A local-density-approximation plus dynamical-mean-field-theory study of FeS for lithium-ion batteries

Abstract

Iron sulfides are promising candidates for the next generation of rechargeable lithium-ion battery materials. Motivated thereby, we present a detailed study of correlation- and doping-induced electronic reconstruction in troilite. Based on local-density-approximation plus dynamical-mean-field-theory, we stress the importance of multi-orbital Coulomb interactions in concert with first-principles band structure calculations for a consistent understanding of intrinsic Mott-Hubbard insulating state in FeS. We explore the anomalous nature of electron doping-induced insulator-bad metal transition, showing that it is driven by orbital-selective dynamical spectral weight transfer. Our results are relevant for understanding charge dynamics upon electrochemical lithiation of iron monosulfides electrode materials for lithium-ion batteries.