Flexible binderless capacitors based on P- and N-containing fibrous activated carbons from denim cloth waste

Activated carbon cloths have been prepared from denim cloth waste (DCW) through chemical activation with H3PO4. The effect of the H3PO4/DCW impregnation ratio and the carbonization temperature on the porous texture, the chemical composition, the fibers morphology and the electrochemical performance has been studied. Low H3PO4/DCW impregnation ratios lead to flexible and microporous activated carbon cloths, whereas more fragile and rigid activated carbon cloths with higher external surface area are produced upon increasing the amount of H3PO4. An increase in the carbonization temperature allows for obtaining a more ordered and conductive carbon structure. The activated carbon prepared at 900 degrees C with an impregnation ratio of 0.5 (wt. H3PO4/wt. DCW) exhibits the best performance as electric double layer capacitor. This electrode shows a specific surface area of 2032 m(2) g(-1) and the highest registered gravimetric capacitance (237 F g(-1)). Moreover, its flexibility minimizes the contact resistance in the electrode, thus increasing the feasibility of working at higher current densities than the other synthesized electrodes. (C) 2018 Elsevier Ltd. All rights reserved.