Structural Disorder Determines Capacitance in Nanoporous Carbons

The difficulty in characterizing the complex structures of nanoporous carbon electrodes has led to a lack of clear design principles with which to improve supercapacitors. While pore size has long been considered the main lever to improve capacitance, our study of a large series of commercial nanoporous carbons finds a lack of correlation between pore size and capacitance. Instead nuclear magnetic resonance spectroscopy measurements and simulations reveal a strong correlation between structural disorder in the electrodes and capacitance. More disordered carbons with smaller graphene-like domains show higher capacitances due to the more efficient storage of ions in their nanopores. Our findings will stimulate a new wave of research to understand and exploit disorder to achieve highly energy dense supercapacitors.