Wearable flexible solid-state supercapacitors: Interface engineering using functionalized hexagonal boron nitride

Abstract

In pursuit of advanced energy storage systems for flexible electronics and sustainable energy applications, we report the development of highly cyclable, rechargeable, flexible solid-state supercapacitors via interface engineering with functionalized two-dimensional (2D) hexagonal boron nitride (hBN) nanoflakes. Functionalized hBN (Fh-BN) was integrated into all compartments of the supercapacitor, including the separator, flexible electrodes, and gel polymer electrolyte (GPE). The incorporation of Fh-BN into the carbon-based electrodes resulted in a 75 % enhancement in specific capacitance, reaching 350 F/g. Furthermore, the introduction of Fh-BN at the separator and GPE interfaces led to exceptional cycling stability, with over 80 % capacitance retention after 50,000 cycles, even under mechanical deformation. Fh-BN nanoflakes demonstrated excellent ion transport properties, facilitating efficient charge/discharge processes across all device components. This study highlights the crucial role of interface engineering in improving the performance of solid-state supercapacitors, offering a highly promising solution for energy storage in flexible electronics and wearable technologies. These results suggest a significant step forward in the design of next-generation energy storage devices with enhanced stability, flexibility, and efficiency.