The Polymer Society of Korea

Abstract

Hydrovoltaic nanogenerators are promising sustainable energy harvesting devices. However, the electrical output of conventional hydrovoltaic nanogenerators is highly dependent on ambient humidity and temperature. In this work, we present an all-hydrogel-based hydrovoltaic nanogenerator that enables humidity- and temperature-invariant potential generation through an asymmetric hydrophilic interface, which establishes a stable ion migration channel for continuous charge separation. The hydrovoltaic nanogenerator exhibits exceptionally stable output potential over a wide temperature range, performing equally well at subzero temperatures and at 60 °C, while maintaining highly stable output current across a humidity range of 25% to 90% relative humidity (RH). Furthermore, the device achieves a remarkably high output power density exceeding 600 µW/cm², demonstrating significant potential for practical applications under extreme environmental conditions.