High performance of chitosan derived porous carbon as supercapacitor electrodes

Abstract

Chitosan, a renewable biomass derivative, was used as electrode material with a facile pyrolysis and activation process for supercapacitors. The physical and electrochemical performances of the as-prepared chitosan-based hierarchical porous carbon (CHPC) were evidently affected by the mass ratio of powder to KOH and the carbonization temperature. The sample obtained at the best powder/KOH ratio of 1:1 exhibits meaningful structural characteristics: optimized interconnected hierarchical pore structure and high specific surface area (863.58 m 2 g -1 ). It possesses excellent capacitive property with high specific capacitance of 310 F g -1 in 6 mol L -1 KOH electrolyte at a current density of 1 A g -1 , and enhanced rate capability (231 F g -1 can be retained at 10 A g -1 ). Additionally, it shows excellent capacity retention of 80% after 10 000 cycles at 10 A g -1 . The efficiently combined and optimized synthesis process and the excellent electrochemical characteristics are of strategic guiding significance to the large-scale application of high-performance supercapacitors.