Optimization of Laser‐Induced Graphene Electrodes for High Voltage and Highly Stable Microsupercapacitors

Microsupercapacitors (µSCs) have received a lot of interest for their possible use in miniaturized electronics and in the field of the Internet of Things (IoT) to power distributed sensors. µSCs fill the gap between batteries and traditional capacitors, providing high power densities and acceptable energy densities to fulfill onboard power supply requirements, coupled with quick charge/discharge rates and extended lifetime. Charge balancing of µSCs is not a standard practice, although the optimization of electrodes can provide beneficial effects on the electrochemical performance and stability of the device. In this work, a charge‐balanced double‐layer µSC based on laser‐induced graphene (LIG) with [PYR14][TFSI] as an ionic liquid electrolyte is presented for the first time. The optimized device shows an improvement in terms of the increased lifetime of a factor of four and its energy efficiency is raised above 80%. Balancing microsupercapacitor electrodes is of paramount importance to increase the devices lifetime. In this work, an optimization strategy is proposed for laser‐induced graphene microdevices, and the effectiveness by means of accelerated ageing tests is shown. The results show an increase in the device's lifetime of a factor of four.