Enhancing the output of cellulose-based triboelectric nanogenerators via dual interfacial polarization effects

Cellulose-based triboelectric nanogenerators (TENGs) have garnered significant attention in wearable electronics due to their biodegradability and abundant availability. However, the near-electroneutrality of cellulose hinders its advancement and broader application in high-performance TENGs. In this study, the triboelectric polarity of cellulose nanofibers (CNF) is modified by grafting different functional groups, wherein the incorporation of polar sulfonic acid groups enhances the deep trap density on the surface of CNF by an order of magnitude, reduces charge dissipation rates, and increases surface potential by nearly 200 % compared to untreated CNF. Subsequently developed cellulose-based bilayer triboelectric materials utilize the dielectric difference between functionalized cellulose and Ecoflex/graphene, as well as that between Ecoflex and graphene, to induce efficient dual interfacial polarization, resulting in a cellulose-based triboelectric material with excellent charge densities as high as 125 μC/m²-surpassing the most electronegative commercially available fluoroethylene propylene. This work presents a simple, scalable method to fabricate high-performance cellulose-based TENGs, highlighting the immense potential of cellulose in wearable electronics.