||Electrochemical performances of hydrothermal tannin-based carbons doped with nitrogen
|| Braghiroli, F. L., Fierro, V., Szczurek, A., Stein, N., Parmentier, J. and Celzard, A.
||Ind. Crops Prod.
||Six porous carbon materials, produced by hydrothermal treatment of flavonoid tannin and subsequent carbonization at 1173 K, were tested as electrodes of supercapacitors. Four of these carbons were doped with nitrogen by putting tannin in contact with ammonia before or during the hydrothermal treatment. The pyrolyzed hydrothermal carbons had moderate surface areas, within the range 442-684 m2 g-1, and nitrogen contents ranging from 0.7 to 8.0 wt.%. Specific capacitances as high as 320 F g-1 and normalized capacitances as high as 58 ?F cm-2 were measured at 2 mV s-1. These performances are comparable with those obtained with high surface area-activated carbons, whereas, normalized capacitances values are among the highest ever reported. Mesostructuration, within the range 3-13 nm, of these materials appears to be a good strategy to improve their electrochem. performances at higher scan rates. We confirmed the beneficial role of oxygen up to 18 wt.%, while an optimum in nitrogen content exists from 3 to 6 wt.%. [on SciFinder(R)]
||Département CP2S : Chimie et électrochimie des matériaux