Electrodeposition and Characterization of Cobalt (Co) Foam with Food-Grade Agar via Dynamic Hydrogen Bubbling Template (DHBT)

Supercapacitors exhibit both high energy and power densities that facilitate the discharge of energy rapidly, but their energy density is inferior to batteries. A porous electrode maximizes the charge capacity of supercapacitors making metal foams widely researched materials. With the hydrogen evolution activity, superior reversible redox reactions, and excellent cyclic stability of cobalt (Co)-based foam, it could serve as an excellent active material and current collector for pseudocapacitor. Dynamic hydrogen bubbling templating (DHBT) is a low-cost, and straightforward electrodeposition technique for synthesizing metal foams. This study synthesized Co foams with food-grade agar as an additive via DHBT. The effect of food-grade agar concentration and current densities were studied wherein the result showed that higher concentration of food-grade agar and current densities led to smaller and more uniform pore sizes. Co foam 0.3% food-grade agar electrodeposited at 2.5 A/cm 2 have the most uniformed structure. The cobalt foam is then oxidized in ambient conditions and employed as both active material and current collector. Co foam with 0.3% agar synthesized at 2.5 A/cm 2 attained a high capacitance from the discharge curves at 211.525 Fcm -2 .