Dynamical evolution of CO<sub>2</sub> and H<sub>2</sub>O on garnet electrolyte elucidated by ambient pressure X-ray spectroscopies.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38555416.
- Also identified by DOI 10.1038/s41467-024-47071-4 and PMC identifier 10981710.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Garnet-type Li6.5La3Zr1.5Ta0.5O12 (LLZO) is considered a promising solid electrolyte, but the surface degradation in air hinders its application for all-solid-state battery. Recent studies have mainly focused on the final products of the LLZO surface reactions due to lacking of powerful in situ characterization methods. Here, we use ambient pressure X-ray spectroscopies to in situ investigate the dynamical evolution of LLZO surface in different gas environments. The newly developed ambient pressure mapping of resonant Auger spectroscopy clearly distinguishes the lithium containing species, including LiOH, Li2O, Li2CO3 and lattice oxygen. The reaction of CO2 with LLZO to form Li2CO3 is found to be a thermodynamically favored self-limiting reaction. On the contrary, the reaction of H2O with LLZO lags behind that of CO2, but intensifies at high pressure. More interestingly, the results provide direct spectroscopic evidence for the existence of Li+/H+ exchange and reveal the importance of the initial layer formed on clean electrolyte surface in determining their air stability. This work demonstrates that the newly developed in situ technologies pave a new way to investigate the oxygen evolution and surface degradation mechanism in energy materials.