Highly disordered nanoporous carbons for enhanced energy storage in supercapacitors.

Abstract

There has been a lack of clear principles for designing nanoporous carbons with enhanced performance in supercapacitors due to their structural complexity. Our recent NMR and Raman spectroscopy studies of a series of commercial nanoporous carbons show that carbons with smaller graphene-like domains have higher capacitance. In this study, we demonstrate that low-temperature synthesis provides a promising route for producing highly disordered nanoporous carbons with enhanced gravimetric and volumetric capacitance. NMR spectroscopy measurements provide unique insights by simultaneously probing local structural order and ion adsorption capacities, revealing that carbons with smaller graphene-like domain sizes and higher ion adsorption capacities generally have better capacitive performance. We finally show that the capacitance of a nanoporous carbon can be predicted directly from the NMR spectra of electrolyte-soaked electrodes. Our findings provide a strategy that can be extended to various carbon precursors and synthesis routes for developing energy storage materials with enhanced capacitance.