Bulk and grain boundary Li-diffusion in dense LiMn2O4 pellets by means of isotope exchange and ToF-SIMS analysis

C Schwab; A Höweling; A Windmüller; J Gonzalez-Julian; S Möller; J R Binder; S Uhlenbruck; O Guillon; M Martin

doi:10.1039/c9cp05128g

Bulk and grain boundary Li-diffusion in dense LiMn₂O₄ pellets by means of isotope exchange and ToF-SIMS analysis

Phys Chem Chem Phys. 2019 Dec 21;21(47):26066-26076. doi: 10.1039/c9cp05128g. Epub 2019 Nov 20.

Authors

C Schwab¹, A Höweling², A Windmüller³, J Gonzalez-Julian³, S Möller³, J R Binder², S Uhlenbruck³, O Guillon³, M Martin⁴

Affiliations

¹ Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52074 Aachen, Germany. martin@rwth-aachen.de.
² Institute for Applied Materials (IAM), Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
³ Institute of Energy and Climate Research (IEK-1), Forschungszentrum Jülich GmbH, Wilhelm-Johnen-Straße, 52428 Jülich, Germany.
⁴ Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52074 Aachen, Germany. martin@rwth-aachen.de and Helmholtz-Institute Münster (IEK-12), Forschungszentrum Jülich GmbH, Corrensstraße 46, 48149 Münster, Germany.

PMID: 31746869
DOI: 10.1039/c9cp05128g

Abstract

Lithium diffusion in LiMn₂O₄ pellets is studied by means of isotope exchange and Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS). A ⁶Li-enriched film deposited by Pulsed Laser Deposition (PLD) on a dense LiMn₂O₄ pellet with natural abundance of lithium isotopes is used to study the tracer diffusion of lithium. The measured profiles are analyzed by numerical models describing the ⁶Li tracer diffusion from the film into the pellet. Experiments in the Harrison type B regime of diffusion kinetics allow for the distinction and simultaneous determination of bulk and grain boundary diffusion coefficients. Changing the experimental conditions to reach Harrison type A behavior yields effective diffusion coefficients for lithium tracer diffusion in LiMn₂O₄. Activation energies for bulk and grain boundary diffusion were obtained from experiments at different temperatures. Our values are critically compared to previous studies.