2024/06/25 by Charles‐Emmanuel Dutoit, Hania Ahouari, Quentin Denoyelle +2 · 1 voice
Engineering · #Advanced Battery Materials and Technologies #Advanced Battery Technologies Research #Advancements in Battery Materials
paper · pdf · doi:10.5194/mr-5-87-2024
openalex publication_date 2024/06/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We have investigated metallic lithium particle nucleation following lithiation and delithiation steps of the graphite electrode using X-band electron paramagnetic resonance (EPR). Metallic lithium aggregates like dendrites and/or filaments which are formed during electrochemical cycling on the graphite anode are complex structures which may lead to internal short-circuit and safety issues. Understanding and following, in real conditions, this nucleation process is necessary to improve the development of Li-ion batteries. The complexity to detect metallic lithium structures inside Li-ion batteries depends on the number of EPR lines and their linewidth. The presence of lithiated graphite phases affects the detection of micrometric Li-metal elements. Herein, we report a new approach using cw-EPR (continuous-wave EPR) spectroscopy and imaging, combining the first- and second-harmonic detection schemes to provide evidence for the metallic lithium aggregate nucleation in these negative electrodes. Although the first harmonic gives all the EPR signals present in the sample, it is found that the second-harmonic EPR signal is mainly sensitive to metallic lithium depositions.