In conclusion, our work demonstrates that low-temperature synthesis is a promising pathway to make nanoporous carbons with enhanced capacitance in EDLCs. Nanoporous carbons synthesised at low temperatures were found to have smaller graphene-like domains and improved gravimetric and volumetric capacitance compared with commercial activated carbons. Through a combination of NMR and Raman spectroscopy, we were able to provide a comprehensive understanding of the structural factors that influence capacitance. NMR spectroscopy, in particular, allowed us to simultaneously evaluate both the sizes of the graphene-like domains and the electrolyte ion adsorption capacities, with electrolyte ions as the probe. Our findings indicate that carbons with smaller graphene-like domains and higher ion adsorption capacity generally show enhanced capacitive performance. The highest gravimetric capacitances were achieved for either highly disordered carbons or carbons with more order but more accessible pores (higher electrolyte ion adsorption capacities), the latter carbons, however, generally being associated with lower volumetric capacitances. We show that the combination of Δδ and the ion adsorption capacity both measured by NMR spectroscopy in a quick and simple NMR experiment (~5 mins) are excellent descriptors for capacitance.