Vinyl sulfones as SEI-forming additives in propylene carbonate based electrolytes for lithium-ion batteries

• Methyl vinyl sulfone and ethyl vinyl sulfone were studied as SEI-additives.
• Already small amount of the additives (2–5%) forms an efficient SEI on graphite.
• Long-term cycling tests in full cells proved the stability of the formed SEI layer.
• The capacity retention is higher compared to the conventional electrolyte.
• The additives showed only slight impact on cathode performance and safety.

The electrochemical performance of propylene carbonate (PC) based electrolytes with methyl vinyl sulfone (MVS) and ethyl vinyl sulfone (EVS) as film-forming additives on graphite electrode was studied. The results indicate that already small amount of these additives is able to form a stable SEI and thus successfully prevent exfoliation of the graphite. Moreover, the tested additives showed slight impact on the cathode performance as well as on the safety characteristics.