A high-performance moisture-enabled generator driven by synergistic ion transport highways and engines

Moisture-enabled generators (MEGs) often suffer from low power output and limited durability. Here, we develop a high-performance MEG based on a novel NMS/CS aerogel integrating hollow mesoporous carbon (MC), polypyrrole (PPy), polystyrene sulfonate (PSS), and chitosan (CS). By precisely tuning solvent ratios and surface potentials, dual ionic and pore gradients are constructed to synergistically enhance device performance. PPy and PSS modification improves electrical conductivity and promotes efficient ion transport. In this architecture, the pore gradient functions as an ion transport "highway", while the ionic gradient acts as a driving "engine", accelerating hydrated H₃O⁺ migration across layered interfaces. Mechanistic investigations reveal that efficient power generation originates from the rapid interlayer migration of hydrated H₃O⁺ ions within the aerogel. Temperature, relative humidity, and electrode materials significantly influence performance, and machine learning analysis identifies key parameters affecting open-circuit voltage and current density. This optimized MEG achieves a V_oc of 0.93 V, an I_sc of 0.87 mA, a current density of 0.28 mA cm^-2, and a power density of 0.09 mW cm^-2, maintaining stable operation for over 30 days with >70% capacity retention after 10 cycles, demonstrating strong potential for energy harvesting and sensing applications.