Loofah-based self-powered triboelectric nanogenerator-supercapacitor for an integrated self-charging energy system

New urbanization is ushering in a surge in construction and amplifying a substantial demand for urban road development, simultaneously spurring innovation and development of environmentally sustainable power sources. Triboelectric nanogenerator (TENG), a revolutionary technology of energy conversion, efficiently capturing high-entropy energy from the environment and offering the advantages of self-powered and immediacy. Recognizing the critical need to store the energy harvested by TENGs, we present an integrated energy conversion and storage system that combines a loofah-based self-powered rotating TENG (LS-TENG) with a supercapacitor. The maximum instantaneous output power and the corresponding instantaneous power density of the LS-TENG are 0.75 mW and 202.69 mW/m 2 at 30 rpm. The supercapacitor, featuring carbon nanotube (CNT) interdigitated electrodes created through microelectronic printing technology, utilizes polyacrylamide (PAM)-lithium chloride (LiCl) as a gel electrolyte (adhesion strength of 16.69 kPa). The supercapacitor is seamlessly integrated onto the back of the LS-TENG’s stator, which effectively simplified the energy conversion and storage system. At a current density of 0.01 mA/cm 2 , the supercapacitor achieves a high volumetric capacitance of 341.47 mF/cm 3 , an energy density of 17.07 mWh/cm 3 , and a power density of 257.07 mW/cm 3 , with a remarkable capacitance retention rate of 99.12 % after 30,000 cycles at a current density of 0.02 mA/cm 2 . Furthermore, a concept demonstration of an integrated self-charging energy system is implemented, in which the supercapacitor can be charged at wind speed rate of 3.0 m/s. The proposed integrated energy storage and conversion system makes it ideal for converting and storing wind energy.