High rate performance activated carbons prepared from ginkgo shells for electrochemical supercapacitors

Partially graphitized ginkgo-based activated carbon (GGAC) is fabricated from ginkgo shells by pyrolysis, KOH activation and heat treatment using cobalt nitrate as graphitization catalyst. The graphitization temperature is 900 °C. The GGAC has a microporous structure and its specific surface area is 1775 m2 g−1. XRD patterns show that the carbon becomes more graphitic after heat treatment. The specific capacitance of the GGAC reaches to 178 F g−1 at a potential scan rate of 500 mV s−1, which is superior to that of commercial activated carbons and ordered mesoporous carbons. The high electrochemical performance of the GGAC is attributed to its good electronic conductivity and high surface area. Partially graphitized activated carbon is a promising electrode material for electrochemical supercapacitors with high rate performance.