ABSTRACT Biomass-based porous Carbon electrodes have been widely used as a basic material for producing supercapacitor cell electrodes, because its application can be applied in the long term, sustainable, renewable, easy to find and has economic value. This research used biomass Guinea grass (RG) with ZnCl2 molarity variations of 0.1 M, 0.3 M, and 0.5 M as carbon electrodes for supercapacitor…