Binary Additive Blends Including Pyridine Boron Trifluoride for Li-Ion Cells

Abstract

Pyridine Boron Trifluoride (PBF)-based electrolyte additive blends for Li[Ni 0.42 Mn 0.42 Co 0.16 ]O 2 (NMC442)/graphite pouch cells have been systematically investigated. Other additives investigated in the blends included methylene methane disulfonate (MMDS) and ethylene sulfate (DTD). Ultra-high precision coulometry (UHPC), electrochemical impedance spectroscopy (EIS), gas evolution and long-term cycling experiments were made. The results obtained in this work indicate that MMDS and DTD have good compatibility with PBF-type additives and some of their combinations showed significant improvements in coulombic efficiency, reducing impedance and maintaining good capacity retention during high-voltage cycling compared to PBF-type additives alone.