High-performance, metal-free planar supercapacitors based on laser-patterned high-quality MXene electrodes

Abstract

The laser ablation technique, a mask-free and efficient method to create customized patterns on various substrates, currently encounters thermal effect-induced issues of electrode quality and performance degradation as well as high cost limitation in practical application specifically in the fabrication of MXene electrodes. In this work, we utilized a common commercial infrared laser marker to fabricate on-chip MXene electrodes, and the thermal effect produced during the laser patterning was effectively alleviated by adopting a simple water-cooling trick. This water-cooling assisted laser ablation (WALA) strategy enabled scalable manufacturing of well-defined, high-quality MXene microelectrodes with diverse configurations, shapes, and integrations on various substrates in a facile, efficient and cost-effective way. The areal mass loading (AML) of MXene in the electrode was tuned to optimize the charge storage performance of the metal-free solid-state supercapacitors. Notably, at an AML of 3 mg/cm² for the MXene electrode, a high areal specific capacitance of 138 mF/cm² and energy density of 6.85 μWh/cm² were achieved. This work demonstrates an easily implementable, efficient, and economically viable strategy for the scalable production of high-quality MXene electrodes for high-performance supercapacitors.