Iurii Timrov^1*, Francesco Aquilante^1*, Matteo Cococcioni^2*, Nicola Marzari^1,3*

1 Theory and Simulation of Materials (THEOS), and National Centre for Computational Design and Discovery of Novel Materials (MARVEL), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland

2 Department of Physics, University of Pavia, via Bassi 6, I-27100 Pavia, Italy

3 Laboratory for Materials Simulations, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland

* Corresponding authors emails: iurii.timrov@epfl.ch, francesco.aquilante@gmail.com, matteo.cococcioni@unipv.it, nicola.marzari@epfl.ch

DOI10.24435/materialscloud:7h-7q [version v1]

Publication date: Sep 20, 2022

How to cite this record

Iurii Timrov, Francesco Aquilante, Matteo Cococcioni, Nicola Marzari, Accurate electronic properties and intercalation voltages of olivine-type Li-ion cathode materials from extended Hubbard functionals, Materials Cloud Archive 2022.118 (2022), https://doi.org/10.24435/materialscloud:7h-7q

Description

The design of novel cathode materials for Li-ion batteries requires accurate first-principles predictions of structural, electronic, and magnetic properties as well as intercalation voltages in compounds containing transition-metal (TM) elements. For such systems, density-functional theory (DFT) with standard (semi-)local exchange-correlation functionals is of limited use as it often fails due to strong self-interaction (delocalization) errors that are especially large for the partially filled d shells of the TMs. Here, we perform the first comparative study of the phospho-olivine cathode materials Li_xMnPO₄, Li_xFePO₄, and mixed-TM Li_xMn_1/2Fe_1/2PO₄ (x=0, 1/4, 1/2, 3/4, 1) using four electronic structure methods: DFT, DFT+U, DFT+U+V, and HSE06. We show that DFT+U+V outperforms the other three methods, provided that the onsite U and intersite V Hubbard parameters are determined from first-principles and self-consistently with respect to the structural parameters by means of density-functional perturbation theory (linear response). In particular, we demonstrate that DFT+U+V is the only method that correctly predicts the digital change in oxidation states of the TM ions in all compounds for the mixed-valence phases occurring at intermediate Li concentrations, leading to voltages in remarkable agreement with experiments. We thus show that the inclusion of intersite Hubbard interactions is essential for the accurate prediction of thermodynamic quantities when electronic localization occurs while in the presence of inter-atomic orbital hybridization. At variance with the other methods, DFT+U+V alone is capable to describe such localization-hybridization interplay, and thus opens the door for the study of more complex cathode materials as well as for a reliable exploration of the chemical space of compounds for Li-ion batteries.

Materials Cloud sections using this data

Files

File name	Size	Description
Files.tar MD5md5:4eab8ac9a821bfb45a0ea2c3594fc14a	1.2 GiB	Collection of all files which were used to produce the data of the paper: input files, output files, references to codes which were used, etc.
README.txt MD5md5:ec60a63202c33fa768a53526f9a76193	3.6 KiB	The README.txt file describes the content of the compressed file "Files.tar"

License

Files and data are licensed under the terms of the following license: Creative Commons Attribution 4.0 International.
Metadata, except for email addresses, are licensed under the Creative Commons Attribution Share-Alike 4.0 International license.

External references

Keywords

DFT+U+V Extended Hubbard functionals Phospho-olivine cathode materials HSE06 hybrid functionals DFT+U MARVEL/OSP CSCS Intercalation voltages Li-ion batteries Formation energy First-principles calculations