Work

Why not inorganic ferroelectrics: Harnessing the pyroelectric charges for triboelectric nanogenerators

Year: 2025

Type: article

Abstract: Multifunctional, ferroelectric fluoropolymers are regarded as the de facto materials for triboelectric nanogenerators. However, their comparatively low polarisation, dielectric constants, and pyroelectric coefficients result in sub-optimal pyroelectric-triboelectric coupling. In contrast, inorganic ferroelectrics, such as lithium niobate (LiNbO 3 ), possess superior electro-physical properties yet remain underutilized in triboelectric applications. This study demonstrates the potential of LiNbO 3 crystals in coupled Pyroelectric-LiNbO 3 Triboelectric Nanogenerators (PL-TENGs) for harvesting waste, low-grade heat and temperature monitoring. Under a 0.11 K.s -1 temperature gradient, the PL-TENG exhibits a 330% increase in output voltage (~720 V p-p ) and a 700% rise in current (~15.2 µA) compared to fluoropolymer-based TENGs (~215 V p-p and ~1.3 µA). This performance advantage is sustained at higher temperatures, with voltage and current increasing by 285% and 395%, respectively, at 353 K compared to 313 K. High voltage Kelvin probe force microscopy reveals a rapid surface potential inversion (+72.6 V to -28.7 V) for a 1 K temperature change, corresponding to a pyroelectric coefficient of -53.4 µC.m −2 .K -1 , validated by in-situ X-ray photoelectron spectroscopy. The increased exchange of pyroelectric effect-induced screening charges amplifies the triboelectric activity, enhancing efficient low-grade heat sensitivity and harvesting. This work underscores the promise of inorganic ferroelectrics like LiNbO 3 for sustainable energy and sensor technologies.

Source: Nano Energy

DOI: 10.1016/j.nanoen.2025.111046