Surface and Diffusion Characteristics of Nanoporous UiO-66/Pineapple Peel-Derived Carbon Composites for Solid-State Supercapacitors

Supercapacitors (SCs) based on hierarchicalnanoporous frameworkcomposite materials and aqueous electrolytes are recent interestsfor the researchers. The structure of UiO-66 exhibits extraordinarystability and high specific surface area, but the specific capacitanceof UiO-66 (139.4 F g(-1) at 2 A g(-1)) is limited due to its moderately conducting nature. Therefore,we report a method to modify UiO-66 with pineapple peel derived activatedcarbon (PA-AC) to form a facile composite. Owing to the high specificsurface area and good conductivity of the UiO-66/PA-AC composite,a high specific capacitance of 295.9 F g(-1) at 2A g(-1) has been achieved and is well suited for supercapacitorapplications. At the maximum charging voltage range of 0-1.8V, the UiO-66/PA-AC//UiO-66/PA-AC symmetrical SC delivered a maximumenergy density of 29.6 Wh kg(-1) at a power densityof 170 W kg(-1). After 5000 repeated charge-dischargecycles at 30 A g(-1), the specific capacitance ofthe device increased from 100% to 120% of its initial specific capacitance.This study emphasized the potential importance of incorporating MOFsinto pores of biowaste derived carbon as a strategy for enhancingthe charge storage kinetics of moderately conducting MOFs.