Gadolinium-based Curie triboelectric nanogenerator for thermal gradient energy harvesting at gas-liquid interface

Abstract

The temperature difference between water and surrounding air in the environment often contains untapped energy. Here, we present the first gadolinium-based Curie triboelectric nanogenerator (GC-TENG) capable of harvesting thermal gradient energy at the gas-liquid interface. This device integrates a Curie engine with a solid-liquid-based triboelectric nanogenerator, enabling efficient two-step energy conversion from thermal gradient to mechanical to electrical energy. The optimized device incorporates ultra-lubricated ceramic bearings and high-performance magnets, achieving over 90 % transmission efficiency. It generates an open-circuit voltage of up to 220 V. Its charge density of 15 mC m⁻³ surpasses previous triboelectric nanogenerator-based thermal gradient energy harvesting technologies. The device's performance is enhanced through several innovations, including a high-efficiency power generator with exceptional bulk charge density characteristics and an optimized Curie engine with custom magnetic field design that boosts thermal conversion efficiency. The GC-TENG demonstrates excellent adaptability and stability, operating autonomously in real-world scenarios such as industrial wastewater discharge points. When combined with a GDT-Buck power management circuit, it effectively powers small electronic devices and enables intelligent monitoring systems. This study significantly expands the application of triboelectric nanogenerators, offering an innovative solution for distributed energy systems and environmental monitoring.