The impact and application of lignin fillers in triboelectric nanogenerators: from performance optimization to sustainable energy technology

Abstract

Lignin-based triboelectric nanogenerators (TENGs) represent an emerging frontier in sustainable energy technologies, demonstrating substantial potential for converting waste biomass into high-performance electronic devices. Owing to its distinctive aromatic structure and abundant functional groups, such as hydroxyl and methoxy, lignin effectively enhances the charge storage capacity, environmental adaptability, and biodegradability of TENGs. This review systematically elucidates the mechanisms underlying performance enhancement achieved through molecular design and composite strategies, emphasizing lignin's role as a functional filler in modulating dielectric properties, optimizing the surface morphology, and improving interfacial charge transfer. Furthermore, an in-depth analysis is provided of the innovative applications of lignin-based TENGs across diverse fields, including self-powered sensing, energy harvesting under extreme conditions (such as high humidity and wide temperature ranges), and biomedical applications, including smart wound dressings and implantable devices. Despite challenges, such as the inherent inhomogeneity of lignin, limited long-term device stability, and difficulties in integration with conventional circuits, ongoing advances in material functionalization, theoretical simulations, and green manufacturing are poised to establish lignin-based TENGs as a pivotal technology for next-generation green and self-powered electronic systems.