High-Performance Aerogel-Based Moisture-Enabled Electricity Generators with Long Working Life for Hydroenergy Harvesting

To address the key challenges of low output, short duration, and difficult integration in moisture-enabled electricity generators (MEGs), we design a bilayer-structured aerogel-based moisture-enabled electricity generator (AMEG). By synergistically integrating a highly porous aerogel evaporation layer, a hygroscopic neutral salt (LiCl) combined with a hydrogel absorption layer, and an asymmetric active metal electrode, the proposed AMEG achieves a maximum open-circuit voltage ( V oc ) of 1.15 V, a short-circuit current ( I sc ) of 637.56 μA, and a power density ( P max ) of 24.36 μW/cm 2 . Notably, the AMEG maintains a stable I sc of 95.84 μA at −15 °C, demonstrating reliable operation under subzero conditions. Furthermore, the output voltage exhibits only minor variations across a bending angle ranging from 0° to 180°, showing excellent flexibility that facilitates large-scale integration. By connecting 30 AMEGs in series or 40 AMEGs in parallel, a voltage of 41.79 V or a current of 18.36 mA can be achieved, respectively, which is sufficient to directly power small commercial electronics. Moreover, three AMEG units connected in series generate enough power to run a small calculator and sustain a red LED for 72 h, and five units series-connected power a wearable watch for 144 h, demonstrating its potential as a wearable power source.