A robust strategy of solvent choice to synthesize optimal nanostructured carbon for efficient energy storage

Abstract

Despite great advances in carbon synthesis through solution chemistry, a long-standing question is how to choose solvents effectively. Herein, we establish a systematical strategy to answer this question, guided by both the difference of total Hansen solubility parameter and the relative energy difference between the solvent and the precursor. This approach can quickly and accurately screen out the “excellent” solvent or solvent mixture from a lot of possible candidates including single, binary and multicomponent systems to synthesize carbon materials with optimal nanostructure and high surface area. We further find it is convenient to get a series of “excellent” solvents by mixing different grades of solvents (“poor”, “fair”, and “good”). This finding gives more opportunities for solvent choice to fabricate well-designed carbons, and also provides an economic and eco-friendly synthetic route by selecting cheap, low- or non-toxic solvents. The robust strategy, which has been applied to different carbon precursors, has already succeeded as a proof of concept. As-synthesized carbons feature sphere-like superstructure and high surface area, delivering fast electrochemical kinetics, ultrahigh energy density and excellent high-rate lifespan in energy storage applications.