Scalable Production of High-Quality Graphene: Insights into Exfoliation Time and Graphite Concentration Effects

Abstract

The exceptional properties of graphene, including its high strength, electrical conductivity, and flexibility, make it a promising material for a wide range of applications. However, its commercial adoption is hindered by challenges in the scalable production of high-quality graphene flakes. This study focuses on optimizing the liquid phase exfoliation (LPE) process, one of the primary techniques for producing graphene at a commercial scale. Among the various LPE processes, fluidic liquid phase exfoliation (FLPE) was employed due to its high-yield and productivity. By systematically investigating the effects of exfoliation time and graphite concentration in FLPE, it was found that an exfoliation time of 10 min maximizes the yield of few-layer graphene flakes. This finding challenges the conventional belief that longer exfoliation durations are more beneficial. In addition, it suggests that this more efficient production process can save both time and energy. Interestingly, the graphite concentration had minimal impact on exfoliation performance, achieving over 60% few-layer graphene flakes at a graphite concentration of 100 g L–1. This indicates that the process is robust across a range of concentrations so it can further simplify the production process. In addition, statistical analyses of cumulative distribution functions were performed to gain insights for making dimensional predictions about the exfoliated graphene flakes. While thickness changes could be predicted to some extent, lateral size changes remained somewhat unpredictable. This study underscores the critical role of exfoliation time in determining graphene quality, and provides valuable insights for the scalable production and improved performance of graphene-based applications.