Nitrogen-Doped Hierarchical Porous Carbon Films Derived\nfrom Metal–Organic Framework/Cotton Composite Fabrics as Freestanding\nElectrodes for Flexible Supercapacitors

Abstract

Carbon-based materials are highly\ndesirable for developing flexible\nsupercapacitor electrodes. However, due to the limitations of the\ncarbon electrode structure including the low accessible active surface\narea, inappropriate porous structure, nonoptimum surface chemical\nstates, and low flexibility, their electrochemical performance is\nnot always the same as expected in flexible supercapacitors. In this\nstudy, we develop a freestanding porous nitrogen-doped carbon textile\nelectrode by carbonizing a ZIF-8/cotton composite fabric without involving\nchemical activation or etching processes. Benefiting from the hierarchical\nporosity, large specific surface area, nitrogen-doped surface, and\nrobust electrode structure, the resulting electrode shows a high specific\ncapacitance of 375.2 F g^–1 (4034 mF cm^–2) at 2 mV s^–1, long cycling life, and good flexibility.\nBesides, the assembled symmetric all-solid-state supercapacitor delivers\nan energy density of 17.0 Wh kg^–1 and has potential\nin powering flexible and wearable electronics.