Molten salt synthesis of capacitive porous carbon from Allium cepa (onion) for supercapacitor application

Efficient and simple conversion of renewable biomass material for energy storage devices have been a recent interesting topic in the world of supercapacitors. Molten salt synthesis was applied in the preparation of capacitive porous carbon. Allium cepa (onion) is used as the carbon source and the molten salt containing KCl was used as a direct structure tailoring agent in improving the electrochemical performance of the porous carbon obtained. The molten salt and biomass were mixed in different compounding ratios. The resulting sample shows the optimal performance of the specific surface area and specific capacitance, and was used as a zinc-ion capacitor electrode to achieve the high capacity of 120 mAh g(-1) and energy density of 119 Wh kg(-1).

Automated summary

The efficient conversion of renewable biomass material into energy storage devices, specifically porous carbon using onion as the carbon source and molten salt synthesis, showed optimal specific surface area and specific capacitance. This porous carbon electrode for zinc-ion capacitors achieved high capacity and energy density.