Supramolecular Excluded-Volume Effect Drives High Performance and Ultra-Durable Moisture Power Generation for Interactive Sensing

Abstract

The rapid proliferation of flexible electronics requires the development of high-power, self-powered systems capable of continuous output. Moisture-electric generators (MEGs) can harvest energy from ubiquitous atmospheric moisture, offering a green and renewable energy source. However, current MEGs still face limitations in terms of current density and operational lifetime. In this study, we engineered supramolecular structures within the hydrogel to induce excluded-volume effects that disrupt the solvation shell of Lithium ions. By enhancing ion dissociation, increasing cation selectivity, and raising the proportion of bound water, this design facilitates rapid cation transport and the long-term preservation of the water gradient. Consequently, the MEG unit achieved an open-circuit voltage of 1.23 V, a power density of 65.3 μW cm-2, and a short-circuit current of 1.06 mA cm-2. The current density is an order of magnitude higher than that of most reported MEGs. The MEG unit can operate continuously with 0.35 mA cm-2 for over 500 hours. More importantly, the MEG arrays configured in series and parallel have been shown to power commercial sensors and to enable contact-based human-machine interaction. This work highlights advancements in high-performance MEGs and their applications in sensing, paving the way for their integration with flexible electronics.