Performance of an Electrochemical double layer capacitor based on coconut shell active material and ionic liquid as an electrolyte

EDLCs based on the modified coconut shell raw material were manufactured with 1-Ethyl-3-methylimidazolium tetrafluoroborate (EMImBF4) as an electrolyte and a typical organic electrolyte based on acetonitrile. Three types of modification of the carbon material with different micro- to mesopore ratios were applied as the positive or negative electrode and tested. Obtained results showed different characteristic capacitances of 150–350 Fg−1, strongly dependent on the type of carbon material. Asymmetric EDLCs were manufactured from different carbon materials as positive and negative electrodes and a mass electrode fitting provided with an EDLC working at 3 V with a specific energy of 68.6 Wh kg−1 and power density of 36 W kg−1.

► Coconut raw materials were tested as electrodes for EDLC.
► Ionic Liquid and Et4NBF4/AN were used as electrolyte and compared.
► The highest capacitances for Carbon/Ionic liquid system have been observed.
► Optimisation of the mass electrodes improve characteristics of the EDLC.