The Li intercalation potential of LiMPO4 and LiMSiO4 olivines with M = Fe, Mn, Co, Ni

TL;DR

This study uses the GGA+U computational method to accurately predict the lithium intercalation potentials of various LiMPO4 and LiMSiO4 olivine compounds, aligning well with experimental data and predicting high potentials for some silicates.

Contribution

It demonstrates that GGA+U provides more accurate potential predictions than standard methods for these olivine materials.

Findings

GGA+U yields potentials within 0.1 V of experimental values for several compounds.

LiNiPO4 potential is predicted to be above 5 V.

LiFeSiO4 and LiCoSiO4 have negligible volume change during lithiation/delithiation.

Abstract

The Li intercalation potential of LiMPO4 and LiMSiO4 compounds with M = Fe, Mn, Co, and Ni is computed with the GGA+U method. It is found that this approach is considerably more accurate than standard LDA or GGA methods. The calculated potentials for LiFePO4, LiMnPO4 and LiCoOPO4 agree to within 0.1 V with experimental results. The LiNiPO4 potential is predicted to be above 5 V. The potentials of the silicate materials are all found to be rather high, but LiFeSiO4 and LiCoSiO4 have negligible volume change upon Li extraction.