Preparation of porous carbons by templating method using Mg hydroxide for supercapacitors

Porous carbons were synthesized by carbonizing a mixture of poly(vinyl alcohol) and magnesium hydroxide, followed by removing template materials. The magnesium oxide formed from magnesium hydroxide worked as a template. The obtained porous carbons were used as electrode materials in a supercapacitor, showing a good rate capability owing to the presence of mesopores. A comparison between magnesium hydroxide and magnesium oxide as a starting material for the template during carbonization showed that the mesopore volume was lower in the hydroxide case, resulting in higher electrode density and volumetric capacitance. The results of a durability floating test showed that the supercapacitor life performance with the proposed porous carbons is significantly better than that with conventional microporous-activated carbons at high current densities. This is attributed to the ability of the mesopores in suppressing the resistance from increasing.