Overall performance improvement of direct-current triboelectric nanogenerators by charge leakage and ternary dielectric evaluation

Abstract

Harvesting sustainable energy from the natural environment, the triboelectric nanogenerator (TENG) has emerged as a promising technology that disrupts the traditional energy production model of utilizing fossil fuels. However, suffering from pulse alternating current characteristics, the conventional TENG has to rely on rectifiers, reducing its portability and integration. Herein, we develop a revolutionary ternary direct-current TENG (T-DC-TENG), which for the first time couples the charge leakage effect and the ternary dielectric triboelectrification effect, improving direct-current TENG's overall performance. Its principle is that the above effects force electrons to circulate in one direction between three tribo-layers and the external circuit, producing a constant direct-current output. We establish a set of comprehensive ternary dielectric evaluation rules for screening triboelectric materials and optimizing performance. The optimized T-DC-TENG has an ultra-high average power density of 6.15 W m⁻² Hz⁻¹ and a historically low crest factor (1.0043), far exceeding previous reports. Demonstrations show a T-DC-TENG lighting up 5568 LEDs, two bulbs (rated power: 50 W), and driving 30 hygrothermographs continuously. This work sets new records for direct-current TENGs and paves the way for practical applications of TENGs as energy harvesters.