Effect of Electrolyte Variations on Physical and Electrical Properties Supercapacitor Electrodes from Theobroma cacao Activated Carbon
Eka Sunitra, Exaudi Pratama Rajagukguk, Rakiman, Muldarisnur, Yuli Yetri

Politeknik Negeri Padang

Abstract

The use of Theobroma cacao shell biomass waste as a base material for supercapacitor carbon electrodes with variations in electrolytes with a chemical activator of 0.4M KOH has been successfully carried out. The process of making activated carbon starts from collecting cocoa pod shells which will be used as sample material. Then the skin is sliced, dried in the sun to dry, pre-carbonized, ground into carbon particles using a mortar and ball milling, then the particle size is uniformed using a sieve. The powder particles obtained are then chemically activated with 0.4M KOH, then molded into carbon monolith coins and finished with integrated pyrolysis. Coin samples were subjected to one-stage integrated pyrolysis with carbonization from room temperature to 600&#730- C in an N2 gas environment. Then proceed with physical activation up to a temperature of 700&#730- C in a CO2 gas environment. Testing of the physical and electrical properties of carbon electrodes was carried out with a variety of electrolytes, namely: H2SO4, KOH, and Na2SO4 at the same concentration of 1M. Characterization was carried out using the Cyclic Voltammetry (CV) and Galvanostatic Charge Discharge (GCD) methods. The results obtained show that the sample immersed in H2SO4 electrolyte has the highest specific capacitance, namely 412.94 F/g at a current of 1 A/g. Based on the results of this research, it is confirmed that activated carbon from cocoa pods has the potential to be used as a source of basic material for electrodes with the H2SO4 electrolyte as a charge carrier source in supercapacitor cell devices.

Keywords: Electrodes, Theobroma cacao, Biomass, Capacitance, Supercapacitors

Topic: Renewable energy