Enhanced High-Temperature Cycle-Life of Mesophase Graphite Anode with Styrene-Butadiene Rubber/Carboxymethyl Cellulose Binder

Abstract

Small (micron)-sized mesophase graphite (SMG) is combined with either styrene-butadiene rubber/carboxymethyl cellulose (SBR/CMC) or polyvinylidene difluoride (PVDF) binder to constitute the anodes for high-power Li-ion batteries. The binder effects on the electrochemical performance of the SMG/LiFePO4 18650-battery are evaluated. Using SBR/CMC binder reduces the first-cycle irreversible capacity loss and most surprisingly enhances the high-temperature (55°C) cycle-life of the battery. Surface analyzes suggest that the enhancements are consistent with reduced formation of the solid-electrolyte-interphase (SEI) layer on graphite anode, indicating that composition of binder can have significant influence on SEI formation on anode.