A highly efficient electrolysis system enabled by direct impedance matching between a charge migration triboelectric nanogenerator and series connected electrolysers

Abstract

As an electromechanical conversion technology, triboelectric nanogenerators (TENGs) are widely used in water electrolysis for hydrogen production. Nevertheless, the impedance mismatch between TENGs and conventional electrolysers significantly reduces energy utilization efficiency, necessitating the integration of power management circuits (PMCs) to mitigate lost energy. Herein, we propose a highly efficient electrolysis system that establishes direct impedance matching between a charge migration triboelectric nanogenerator (CM-TENG) and series-connected electrolysers (SCEs). By leveraging the charge migration of polyurethane and repositioning the tribo-material's back-electrode, the surface charge density of the CM-TENG is enhanced to 306.2 μC m⁻². With systematic parameter optimization, the matched impedance of the CM-TENG is reduced to 2.5 MΩ, delivering a peak power of 451.6 mW. Furthermore, through the serpentine-connected array of electrolytic cells, the impendence of 200 SCEs is tuned to perfectly match that of the CM-TENG. Under motor-driven CM-TENG operation, this system achieves an energy utilization efficiency of 98.9%, along with a hydrogen production rate of 1851.9 μL min⁻¹ m⁻², which is 7.1 times higher than what is obtained using PMCs. This work not only promotes the progress of green hydrogen production but also provides guidance for highly efficient triboelectric self-powered systems.