High voltage rotary freestanding triboelectric nanogenerator with novel electrode pair relative position: Theoretical and experimental studies

Triboelectric nanogenerators (TENGs) are widely used as ideal high-voltage sources in high-voltage equipment. However, there are still some high-voltage application demands that exceed the voltage range of traditional TENG. Here, we propose a high-voltage rotary freestanding TENG (HRF-TENG) with a simple structure. The HRF-TENG device is obtained by changing the relative positions of the electrode pairs (reducing the capacitance) in the traditional RF-TENG, which is inspired by the finite element (FEM) calculation of the traditional RF-TENG. The high-voltage mechanism is initially studied through FEM calculation and experiments, and the calculated output voltage can reach over 30 kV at 500 rpm. In addition, the current direction remains unchanged regardless of the rotation direction. The ultrahigh voltage from HRF-TENG is sufficient to break down the air gap to generate ozone, which achieves the ozone drinking water sterilization system. Drinking water containing 10⁷ CFU/ml of E. coli and S. aureus can be completely sterilized within 24 min and 28 min, respectively. Meanwhile, the electrospinning system can be directly driven by HRF-TENG without any circuit. All of these demonstrations prove the feasibility of HRF-TENG in the field of high-voltage applications. In summary, this work provides useful guidance for designing TENGs for high-voltage applications.