Effect of Liquid Electrolyte Soaking on the Interfacial Resistance of Li7La3Zr2O12 for All-Solid-State Lithium Batteries

Effect of Liquid Electrolyte Soaking on the Interfacial Resistance of Li7La3Zr2O12 for All-Solid-State Lithium Batteries

TitleEffect of Liquid Electrolyte Soaking on the Interfacial Resistance of Li7La3Zr2O12 for All-Solid-State Lithium Batteries
Publication TypeJournal Article
Year of Publication2020
AuthorsMünir M Besli, Camille Usubelli, Michael Metzger, Vikram Pande, Katherine Harry, Dennis Nordlund, Sami Sainio, Jake Christensen, Marca M Doeff, Saravanan Kuppan
JournalACS Applied Materials & Interfaces
Volume12
Issue18
Pagination20605 - 20612
Date Published04/2020
ISSN1944-8244
Abstract

The impact of liquid electrolyte soaking on the interfacial resistance between the garnet-structured Li7La3Zr2O12 (LLZO) solid electrolyte and metallic lithium has been studied. Lithium carbonate (Li2CO3) formed by inadvertent exposure of LLZO to ambient conditions is generally known to increase interfacial impedance and decrease lithium wettability. Soaking LLZO powders and pellets in the electrolyte containing lithium tetrafluoroborate (LiBF4) shows a significantly reduced interfacial resistance and improved contact between lithium and LLZO. Raman spectroscopy, X-ray diffraction, and soft X-ray absorption spectroscopy reveal how Li2CO3 is continuously removed with increasing soaking time. On-line mass spectrometry and free energy calculations show how LiBF4 reacts with surface carbonate to form carbon dioxide. Using a very simple and scalable process that does not involve heat-treatment and expensive coating techniques, we show that the Li–LLZO interfacial resistance can be reduced by an order of magnitude.

DOI10.1021/acsami.0c06194
Short TitleACS Appl. Mater. Interfaces
Refereed DesignationRefereed