Synthesis of highly crystalline electrochemically exfoliated graphene as a conductive additive for lithium-ion batteries

Abstract

This study introduces a cost-effective electrochemical exfoliation technique for producing highly crystalline graphene from graphite. By optimizing key exfoliation parameters, including voltage, electrolyte concentration, and temperature, the efficiency of the exfoliation process and the quality of the resulting graphene were significantly improved. To further enhance crystallinity, minimize defect sites, and achieve superior material properties, the as-prepared electrochemically exfoliated graphene (AeEG) underwent post-heat treatment at temperatures ranging from 1500 to 2950 °C. When employed as a conductive additive, eEGs heat-treated at 1800 °C or higher significantly improved both cycle stability and rate performance in LIB coin cells, while maintaining a discharge capacity approximately 10–12 mAh/g higher than that of the control, which utilized Super P. The enhanced performance is attributed to the formation of an efficient conductive network and superior electron transport properties, driven by the high crystallinity and large aspect ratios of the heat-treated eEGs. These findings highlight the potential of eEG as a highly effective conductive additive for advanced battery industries, offering significant improvements in energy storage performance, specific capacity, and rate characteristics.