Lecithin-Derived N-Doped Carbons for Supercapacitor Electrode Material

Soybean lecithin, plant derived surfactant, is a well-known natural surfactant in the animal tissue, food, and paints industry. Because of lecithin production is huge amount annually, it is urgent to find additional application of lecithin. In this work, an active supercapacitor electrode material is synthesized from lecithin-derived biomass material. Lecithin (as a carbon source) was first converted into bio-char via hydrothermal carbonization (HTC) then urea was introduced as a nitrogen source for biochar. Up to a 4 wt.% nitrogen intercalating into carbon was achieved. The morphology, thermal stability, and surface properties of lecithin, bio-char and N-doped carbon were examined. The resulting material show high surface area with micro/meso porosity. The capacitive characteristics of as-prepared materials were investigated by means of cyclic voltammetry (CV) (from 1.0 to 100 mV s^-1) and charge-discharge (from 1.0 to 20 A g⁻¹ respectively. NGC-800 exhibited the highest capacitance value (411 F g⁻¹ at 1 mV s^-1 scan rate via cyclic voltammetry and 495 F/g at 1 A g⁻¹ current density in 1 M KOH. Therefore, this study suggests that N-doped graphitic carbon materials synthesized from lecithin may be environmentally-sustainable candidate for energy storage applications.