High-performance triboelectric-electromagnetic hybrid nanogenerator using dual-functional flexible neodymium iron boron/ethyl cellulose (NdFeB/EC) composite films for wind energy scavenging

Abstract

Triboelectric-electromagnetic hybrid nanogenerator (HNG) with high output performance provides a very promising solution for realizing self-powered microelectronic devices. However, the complex structures and large mass of traditional HNGs make them difficult to prepare and carry. In this study, a rotating HNG based on flexible neodymium iron boron/ethyl cellulose (NdFeB/EC) composite films was designed for wind energy scavenging. A lightweight composite film with triboelectric and ferromagnetic properties, which can significantly reduce the weight of the rotor, was prepared to replace the magnet. Operated at a wind speed of 15.5 m/s, the triboelectric nanogenerator (TENG) unit of the optimized HNG with an interdigitated electrode gap of 2 mm can generate an open-circuit voltage (Voc) and a short-circuit current (Isc) of 55 V and 5.4 μA, respectively. The maximum power of TENG is 99.2 μW under the condition of an external load resistance of 10 MΩ. The corresponding electromagnetic generator (EMG) unit can produce Voc and Isc of approximately 0.16 V and 59.3 μA, delivering an output power of 2.5 μW at a matched loading resistance of 2.3 kΩ. Compared to the individual TENG or EMG units, the HNG exhibited better charging performance. A 470 μF capacitor can charge to 3.4 V within 600 s, and the stored energy can successfully power a commercial soil temperature–humidity meter to work continuously for 75 s and light 30 blue LEDs in parallel. This research is of great scientific significance for developing triboelectric–ferromagnetic dual-functional materials and designing highly integrated and lightweight HNGs.