Enhanced areal capacitance through potassium incorporation into the graphene framework of laser-induced graphene for flexible electronics using LiCl gel electrolyte

The present study investigated the preparation of a high-performance supercapacitor based on potassium ion-doped laser-induced graphene in a LiCl gel electrolyte. Detailed analysis of the obtained materials was carried out by using Raman spectroscopy, high-resolution transmission electron microscopy, and energy-dispersive spectroscopy. In addition, more fabrication steps for electrochemical electrodes with and without doping were executed and further tested by using an areal electrode configuration. In this respect, the areal capacitance of the potassium-doped laser-induced graphene capacitor increased by 90%, which was enhanced from 11 mF cm-2 at 0.75 mA cm-2 to 21 mF cm-2 at the same current density. This great enhancement indicates a low-cost and high-performance supercapacitor for wearable or flexible electronics applications. Besides that, cycling stability over 2,000 cycles has been investigated for these electrodes, which showed good stability throughout the electrochemical investigation of the LiCl gel electrolyte. The areal energy stored by the capacitor with doped graphene was higher than that reported for the pristine one.