Theoretical insight into the strain effect on the intercalation potential of Li–FePO4 materials

Abstract

We conducted a theoretical investigation on the relative energetic and magnetic stabilities of Li–FePO₄ using density functional theory combined with an effective approach for the exchange and correlation: the semi-local generalized-gradient approximation GGA + U. The intercalation potential resulting from stress on Li–FePO₄ has been unequivocally demonstrated. The fully minimized structural parameters and elastic energies of FePO₄ and LiFePO₄ compounds are resolved. The strain effects on the chemical potential have been addressed in the framework of the atomistic approach. The hysteresis voltages obtained using our approach are in excellent agreement with the experimental observations of M. Gaberšček et al., Nature Mat., 2010, 9, 448. Our results indicate that the analysis of the phase growth morphology provides an effective model that is capable of determining the voltage procedure for Li intercalation under the impact of strain in nanostructured olivine.