Tremella derived ultrahigh specific surface area activated carbon for high performance supercapacitor

Activated carbons derived from sustainable biomass have attracted widespread attention as electrode materials for supercapacitors due to their economic value, tunable physical/chemical properties and environmental concern. Tremella, renewable and abundant biomass, has been explored as precursor to prepare hierarchical activated carbons by means of carbonization and KOH activation. The obtained sample possesses an ultrahigh BET specific surface area of 3760 m2 g−1 and very high mesopore volume ratio of 72%. So, the sample shows a superior specific capacitance 71 F g−1 at 1 A g−1; extraordinary rate performance with a capacitance of 53.5 F g−1 at 30 A g−1; outstanding cycle stability with 99% capacitance retention after 10,000 galvanostatic charge-discharge cycles at 5 A g−1 in a symmetric two-electrode supercapacitor with 6 M KOH solution as electrolyte. The assembled supercapacitor shows a superior energy density of 65.6 W h kg−1 in ionic liquid electrolyte system and 28 W h kg−1 is still maintained even at an ultrahigh power density 19,700 W kg−1.