Raman Spectroscopy Measurements Support Disorder-driven Capacitance in Nanoporous Carbons

Our recent study of 20 nanoporous activated carbons showed that a more disordered local carbon structure leads to enhanced capacitive performance in electrochemical double layer capacitors. Specifically, NMR spectroscopy measurements and simulations of electrolyte-soaked carbons evidenced that nanoporous carbons with smaller graphene-like domains have larger capacitances. In this study we use Raman spectroscopy, a common probe of local structural disorder in nanoporous carbons, to test the disorder-driven capacitance theory. We find that nanoporous carbons with broader D bands and smaller ID/IG intensity ratios exhibit higher capacitance. Most notably, the ID/IG intensity ratio probes the in-plane sizes of graphene-like domains and supports the findings from NMR that smaller graphene-like domains correlate with larger capacitances. Our study supports disorder-driven capacitance in nanoporous carbons and shows that Raman spectroscopy is a powerful technique for the rapid screening of nanoporous carbons with superior performance in supercapacitors.