First-principles prediction of redox potentials in transition-metal compounds with LDA+U

TL;DR

This paper demonstrates that using the DFT+U method with a self-consistent U parameter significantly improves the accuracy of predicted redox potentials in transition-metal compounds, aligning well with experimental lithium intercalation voltages.

Contribution

The study introduces a self-consistent DFT+U approach to accurately predict redox potentials in transition-metal compounds, addressing limitations of traditional LDA/GGA methods.

Findings

Accurately reproduces lithium intercalation voltages

Improves redox potential predictions in transition-metal compounds

Addresses self-interaction errors in DFT calculations

Abstract

First-principles calculations within the Local Density Approximation (LDA) or Generalized Gradient Approximation (GGA), though very successful, are known to underestimate redox potentials, such as those at which lithium intercalates in transition metal compounds. We argue that this inaccuracy is related to the lack of cancellation of electron self-interaction errors in LDA/GGA and can be improved by using the DFT+$U$ method with a self-consistent evaluation of the $U$ parameter. We show that, using this approach, the experimental lithium intercalation voltages of a number of transition metal compounds, including the olivine Li$_{x}$MPO$_{4}$ (M=Mn, Fe Co, Ni), layered Li$_{x}$MO$_{2}$ ($x=$Co, Ni) and spinel-like Li$_{x}$M$_{2}$O$_{4}$ (M=Mn, Co), can be reproduced accurately.