Electrochemical Production of Exfoliated Graphene: Scale-up and Applications
Authors: Roberts Edward , Singh Ashutosh Kumar , Sadri Rad , Liu Yiran , Cao Yifan 
Published: December 2024

We have previously reported on the production of high quality graphene nanoplatelets by anodic electrochemical intercalation / exfoliation of graphite in simple aqueous salt solutions [1-3]. The process is attractive as it operates under ambient conditions, achieves a relatively high yield, and the graphene product does not require thermal or chemical reduction. In addition, heteroatom doping and surface functionalization ensure effective dispersion (enabling simple processing) and excellent performance for a range of applications, including supercapacitors [4,5], redox flow batteries [6], CO2 capture [7], and water treatment [8]. A key step for widespread implementation of electrochemically exfoliated graphene in these applications is the scale up of the process for cost effective production. In this study, a range of scale-up challenges have been evaluated, including the applied current density, temperature control, electrode dimensions and thickness, current connections, electrolyte volume and flow conditions, water purity, electrolyte recycling. The results demonstrate the scalability of the process, but also highlight critical issues that must be considered to enable successful scale-up. In particular, selection of the electrode dimensions must consider the potential and current distribution in the graphite working electrode. Temperature control is also important, since significant joule heating of the electrolyte occurs as the process is scaled up. A material and energy balance reveals that electrolyte management / recycling will be important for reducing waste. Economic analysis suggests that more than half of the cost of production is associated with the graphite foil raw material, and significantly lower cost may be achieved by changing to the process to a packed bed graphite flake electrode.
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