Corn husk derived activated carbon with enhanced electrochemical performance for high-voltage supercapacitors

By M. U. Rani, Katchala Nanaji, T. Rao, Anand Deshpande. 2020

261 citations recorded by the source corpus.

Abstract Porous carbons are considered as promising electrode materials for supercapacitors due to their excellent microstructural properties. Synthesizing porous carbon from a bio-waste material has received significant importance due to their natural abundance and low-cost. Here we report the synthesis of porous carbon from a bio-waste, sweet corn husk precursor. Influence of morphology and crystallinity of pre-activated carbon on the microstructural properties of the resultant activated carbons are studied. The chemical activation method results in carbon with turbostratic nature, high specific surface area (1370 m2 g-1) with large mesoporous volume fraction and 2D layered-like morphology. Similar specific surface area is observed for samples prepared with the variation in the amount of activating agent due to higher pre-carbonization temperature. The resultant activated carbon (ASCH-1:1) shows a specific capacitance of 127 F g−1 with low energy density (4.4 Wh kg−1) in 6 M KOH electrolyte. A high energy density of 20 Wh kg−1 is obtained in 1 M TEABF4/AN electrolyte with a high specific capacitance of 80 F g−1 at 1 A g−1. It shows good cyclic stability by retaining 90% of initial capacitance after 5000 cycles at 2 A g−1. Our results demonstrate that activated carbons reported here are promising materials for high operating voltage supercapacitors.

Subfields: Electrical and Electronic Engineering, Electronic, Optical and Magnetic Materials

View Paper: https://www.semanticscholar.org/paper/e7593f2c9412ff7849e56a359a4822a277741ae2