Impact of lithium bis(fluorosulfonyl)imide (LiFSI) concentration on lithium intercalation into graphite monitored with Step Potential ElectroChemical Spectroscopy (SPECS)

• Published in: Electrochimica acta 2023-09, Vol.463, p.142796, Article 142796
• Main Authors: Maćkowiak, Adam, Galek, Przemysław, Jeżowski, Paweł, Fic, Krzysztof
• Format: Article
• Language: English
• Subjects: Galvanostatic intermittent titration technique; Ions diffusion; Lithium bis(fluorosulfonyl)imide; Lithium-graphite intercalation; Step potential electrochemical spectroscopy
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2023.142796

Step Potential Electrochemical Spectroscopy (SPECS) analysis of lithium intercalation into graphite was performed. Four different solutions of lithium bis(fluorosulfonyl)imide (LiFSI) salt in EC:DMC solvent (1:1, v:v) with various concentrations (0.1, 1, 5 and 10 mol L−1) were selected as electrolytes. SPECS allowed for calculating the capacity resulting from lithium intercalation between the graphite layers and the capacity that comes from the adsorption of ions on the outer electrode surface, resistance, as well as the diffusion coefficient. Additionally, to compare the results obtained, the galvanostatic intermittent titration technique (GITT) was performed under the same conditions. However, it turned out that initially, similar diffusion parameters are not identical in their meaning. Hence, SPECS can offer fresh insights into the lithium intercalation process in highly concentrated electrolytic solutions, enhancing existing approaches. [Display omitted]