Humidity-induced dynamic coordination drives the oscillatory migration of ions for sustainable energy harvesting

Moisture-induced ion diffusion in nanostructured materials is a promising route for high-performance power generation, yet achieving the continuous ion migration necessary for long-term operation remains challenging. Here, we report a moisture-electricity conversion mechanism capable of sustained electrical output. We demonstrate that humidity fluctuations regulate the dynamic coordination between iodide ions (I - ) and iodine molecules (I 2 ), driving the oscillatory migration of I - to generate a continuous alternating ion current (AC). Crucially, this coordination process avoids charge exchange, while electricity generation is achieved through moisture-driven ion transport. The device achieves a current output of 33.2 µA cm - ² and exhibits sustainable performance recovery under natural humidity fluctuations. This mechanism remains effective even under minimal humidity gradients (13% RH), ensuring adaptability to diverse weather conditions. Our strategy, applicable to various gel materials, utilizes environmental humidity fluctuations as a power source for ion diffusion, offering a fundamental solution for long-term, autonomous energy harvesting.