Development of a self-charging power system with a triboelectric nanogenerator and a compressible hybrid supercapacitor spacer

Abstract

This study developed a high-performance compressible triboelectric nanogenerator (TENG) by using electrospun polytetrafluoroethylene/carbon nanotube nanofibers as the negative triboelectric layer and a roughened nylon film as the positive triboelectric layer. This TENG achieved an open-circuit voltage of 240 V and a short-circuit current of 12 μA, with a maximum power density of 7.9 W/m² at an external load resistance of 5 MΩ. Its electrical output was systematically evaluated under different applied forces and operating frequencies to assess its ability to harvest mechanical energy. After 14,000 operating cycles, the device retained 98.7% of its initial output. The energy harvested was sufficient to charge a 100-μF capacitor and power 32 light-emitting diodes, indicating the device’s excellent operational stability and strong energy-harvesting ability. In addition, a compressible hybrid supercapacitor (HSC) was fabricated using conductive foam as the electrode substrate, with MnO₂ and activated carbon serving as the positive and negative electrode materials, respectively. The foam–MnO₂ electrode achieved an areal capacitance of 219.8 mF/cm² at a current density of 1 mA/cm² in a three-electrode configuration, and the HSC achieved an areal capacitance of 55.9 mF/cm² at the same current density. In addition, the HSC retained 91.9% of its initial capacitance after 12,000 charge–discharge cycles and maintained 84% capacitance retention at 60% compression. Finally, the compressible HSC was integrated into the TENG as an energy-storage component and spacer to construct a compact self-charging power system capable of powering 88 red light-emitting diodes for approximately 136 s.