Sustainable Moisture-Electric Generator Based on Electrospun PVA Membranes with Phytic Acid-Enhanced Proton Conduction

Moisture-electric generators (MEGs) can continuously harvest clean electricity from ubiquitous environmental water vapor, making them promising candidates as power sources for next-generation low-power wearable electronics. However, existing MEG devices still face significant challenges in output performance, stability, and environmental adaptability, particularly exhibiting low output voltage and structural instability. To address these challenges, this study presents a high-performance MEG based on poly(vinyl alcohol)/phytic acid (PVA/PA) composite nanofibers. A three-dimensional cross-linked porous hydrophilic network was fabricated via electrospinning, enabling efficient proton dissociation and excellent electrical output performance. Under 97% relative humidity (RH), a single MEG with an effective area of 2 cm2 delivers a sustained open-circuit voltage (VOC) of 0.81 V and a short-circuit current (ISC) of 3.1 μA, achieving a peak power output of 0.65 μW. Notably, the device demonstrates excellent structural and operational stability, maintaining high-efficiency power generation for over 7 days, and can completely dissolve in water within about 5 h and fully biodegrade under natural conditions within ∼120 h. Density functional theory (DFT) calculations reveal that the synergistic PVA/PA system exhibits a strong binding affinity toward water molecules, with a binding energy of −1.602 eV, further supporting its efficient moisture uptake and proton dissociation mechanism. Furthermore, the MEG device can be integrated in series or parallel configurations using multiple units to meet diverse voltage and current requirements. It has been successfully applied to capacitor charging and breath monitoring, demonstrating broad potential for use in self-powered wearable electronic systems.