A combination of lithium difluorophosphate and vinylene carbonate as reducible additives to improve cycling performance of graphite electrodes at high rates

Abstract

Lithium difluorophosphate (LiDFP) as a reducible additive is employed to overcome the unsatisfactory rate capability and cycling instability of highly pressed graphite electrodes with high mass loading (8.1 mg/cm2) with a vinylene carbonate (VC)-derived surface film that hampers the charge transport at the graphite-electrolyte interface at high rates. Our investigation reveals that LiDFP modifies the surface chemistry induced by VC and makes a more ionically conductive surface film on graphite, ensuring good rate capability.