Optimizing the micropore–to–mesopore ratio of carbon–fiber–cloth creates record–high specific capacitance

Abstract The application of commercial carbon fiber cloth (CFC) in energy storage equipment is limited by its low specific capacitance and energy density. By a simple one–step activation treatment, the specific surface area of CFCs with porous structure can be increased considerably from 3.9 up to 875 m2/g and the electrochemical properties of CFCs can be improved by three orders of magnitude (1324 mF/cm2). Moreover, the hydrophobicity of CFCs can be transformed into superhydrophilicity. However, the electrochemical performance of CFCs does not show a positive correlation with specific surface area but have a strong relationship with the hierarchical pore distribution forged by the annealing treatment. Only moderate micropore and mesoporous ratio enables optimizing the electrochemical performance of CFCs.