Monitoring metallic sub-micrometric lithium structures in Li-ion batteries by in situ electron paramagnetic resonance correlated spectroscopy and imaging.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33658494.
- Also identified by DOI 10.1038/s41467-021-21598-2 and PMC identifier 7930082.
- 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
Monitoring the formation of dendrites or filaments of lithium is of paramount importance for Li-based battery technologies, hence the intense activities in designing in situ techniques to visualize their growth. Herein we report the benefit of correlating in situ electron paramagnetic resonance (EPR) spectroscopy and EPR imaging to analyze the morphology and location of metallic lithium in a symmetric Li/LiPF<sub>6</sub>/Li electrochemical cell during polarization. We exploit the variations in shape, resonance field and amplitude of the EPR spectra to follow, operando, the nucleation of sub-micrometric Li particles (narrow and symmetrical signal) that conjointly occurs with the fragmentation of bulk Li on the opposite electrode (asymmetrical signal). Moreover, in situ EPR correlated spectroscopy and imaging (spectral-spatial EPR imaging) allows the identification (spectral) and localization (spatial) of the sub-micrometric Li particles created by plating (deposition) or stripping (altered bulk Li surface). We finally demonstrate the possibility to visualize, via in situ EPR imaging, dendrites formed through the separator in the whole cell. Such a technique could be of great help in mastering the Li-electrolyte interface issues that plague the development of solid-state batteries.