Binder-Free Flexible Chickpea Pod Derived Activated Carbon-Carbon Nanofiber Composite for Supercapacitor Application

Abstract

In the present study, a novel carbon-carbon composite electrode was prepared by embedding activated carbon derived from chickpea pods and evaluating its potential as an electrode for supercapacitors. A simple, single-step electrospinning technique was used for the synthesis of activated carbon-carbon nanofiber composite. The synthesized activated carbon-carbon nanofiber composite electrode is flexible and binder-free with high specific surface area, micro and meso pores, interconnected fiber-to-flake morphology and possess high graphitization. Additionally, rapid electrolyte diffusion has resulted in a low charge transfer resistance due to interconnected morphology. In 6 M KOH electrolyte, composite binder-free electrode shows a specific capacitance of 147 F g-1 at 0.5 A g-1 compared to activated carbon electrodes that showed a specific capacitance of 120 F g-1 at 0.5 A g-1. It exhibits an energy density of 13 Wh k g-1 at 0.366 W k g-1 power density. It also showed impressive cyclic stability by retaining 93.5 % of initial capacitance till 1200 cycles at 1 A g-1. Overall, the study presents an easy-to-use, low-cost, eco-friendly, and flexible electrode for supercapacitors that is free of binder.