ZIF-8-derived hierarchical ZnO nanoplates anchored to low-density carbon fabric: Highly flexible supercapacitors with wide potential windows

Flexible supercapacitors are preferred for small wearable electronics owing to their sustainability and high power density. These systems can be fabricated using low-density, conductive, flexible carbon materials, which are primarily obtained using cotton fabrics. For instance, cotton-fabric-derived carbon cloth comprises a three-dimensional network of conductive fibers that can hierarchically accommodate electrochemically active materials. In this context, the present article reports the decoration of a cotton fabric with two-dimensional ZIF-8 nanoplates by wet chemical impregnation followed by high-temperature annealing. Tailoring the ratio of the zinc salt to 2-methylimidazole enhances the exposure of electrochemically active sites. The optimal specimen exhibits the highest capacitance among the samples (982.8 mF cm−2), as ascertained by cyclic voltammetry at a scan rate of 10 mV s−1, whereas in terms of electrochemical stability, it shows a capacitance retention of 91% after 10,000 galvanostatic charge–discharge cycles. Furthermore, in a potential window of 0–1.6 V, ZnO nanoplates anchored to low-density carbon fabric aids in storing an energy density of 261.3 μW h·cm−2 at a high power density of 11.2 mW cm−2.