Synergistic boosting electrical output of moisture-electric generator based on CCNF-LiCl-PAM hydrogel

Abstract

Moisture-electric generators (MEGs) that convert chemical potential energy of atmospheric moisture into electricity through directional ion diffusion have held great promise in the development of sustainable energy. However, current MEGs still encounter considerable challenges of low electrical output and rapid voltage decay due to insufficient ion concentration gradient and low-efficiency ion migration. Herein, we develop a high-performance MEG based on a carboxylated cellulose nanofiber (CCNF)/LiCl-embedded polyacrylamide (PAM) hydrogel (CLP) sandwiched between laser-induced graphene (LIG) and porous Zn electrodes. The incorporation of CCNF into PAM hydrogel enables abundant dissociated ions and efficient ion transport channels. Synergistic enhancement of hygroscopic LiCl, functional groups of CCNF, and interfacial reactions of Zn electrode achieves strong moisture gradient, high-efficiency ion transport, and continuous ion supply in the CLP-MEG, yielding remarkable electrical outputs of 1.92 V and 2.44 mA cm⁻² at 60% RH. Especially, the device can maintain an output voltage of 1.34 V even after 90 days, significantly outperforming most reported MEGs. Furthermore, the integrated CLP-MEGs connected in parallel or in series are capable of powering twelve hygro-thermographs, 3 × 1.0 W lamps, and one smartphone, respectively. This work demonstrates a novel strategy to develop high‑performance durable MEG.