Li Dynamics in Mixed Ionic-Electronic Conducting Interlayer of All-Solid-State Li-metal Batteries.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38270095.
- Also identified by DOI 10.1021/acs.nanolett.3c04072 and PMC identifier 10853963.
- 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
Lithium-metal (Li<sup>0</sup>) anodes potentially enable all-solid-state batteries with high energy density. However, it shows incompatibility with sulfide solid-state electrolytes (SEs). One strategy is introducing an interlayer, generally made of a mixed ionic-electronic conductor (MIEC). Yet, how Li behaves within MIEC remains unknown. Herein, we investigated the Li dynamics in a graphite interlayer, a typical MIEC, by using <i>operando</i> neutron imaging and Raman spectroscopy. This study revealed that intercalation-extrusion-dominated mechanochemical reactions during cell assembly transform the graphite into a Li-graphite interlayer consisting of SE, Li<sup>0</sup>, and graphite-intercalation compounds. During charging, Li<sup>+</sup> preferentially deposited at the Li-graphite|SE interface. Upon further plating, Li<sup>0</sup>-dendrites formed, inducing short circuits and the reverse migration of Li<sup>0</sup>. Modeling indicates the interface has the lowest nucleation barrier, governing lithium transport paths. Our study elucidates intricate mechano-chemo-electrochemical processes in mixed conducting interlayers. The behavior of Li<sup>+</sup> and Li<sup>0</sup> in the interlayer is governed by multiple competing factors.