Sucrose-based activated carbon foams as an electrode active material for supercapacitors

Activated carbon foams (ACFs) have been successfully prepared by foaming sucrose with Zn nitrate and further chemical activation with H3PO4. The effect of the foaming agent (Zn) concentration and the activation temperature on the surface chemistry, porosity, and morphology were investigated. The ACFs reveal high specific surface area, non-uniform variable porous structure, and high oxygen content. The ACFs represent high specific capacitance and very low equivalent serial resistance (ESR) values as electrode material. The ACF obtained at 600 degrees C has a specific capacitance of 205.4 F/g at 1 A/g constant current density. The pseudocapacitive contribution of oxygen-containing surface functional groups was proved by CV curves at slow scan rates. The high performance of the ACFs may be attributed not only to the high surface area, and hetero-atom-containing SGFs but also to the unique surface morphology which originated from the release of gaseous products during the foaming process.