Proton-Conducting\nPolyelectrolyte Membranes Containing\nGraphene Dots for Moisture Electric Generators

Polyelectrolyte membranes used in moisture-electric generators\n(MEGs) typically face the challenge of producing high voltage but\nlow current. In this study, a PSSA/PVA/GDs membrane (PPGM) was developed\nby incorporating graphene dots (GDs) into the poly(styrene sulfonic\nacid) (PSSA) and poly(vinyl alcohol) (PVA) composite system. The abundant\noxygen-containing groups in GDs enhance hydrogen bonding and increase\nthe cross-linking density, thereby improving the tensile strength\nof the PPGM to 25.77 MPa. Additionally, GDs endow the polyelectrolyte\nmembrane with excellent hydrophilicity and a notable self-healing\ncapability. The uniform dispersion of GDs, coupled with their excellent\nelectrical properties, facilitates the formation of rapid proton transport\nchannels, which, in turn, enhances the ionic conductivity to 1.41\nS/m. Under a relative humidity (RH) of 83%, the membrane (1 cm<sup>2</sup>) can deliver an open-circuit voltage (<i>V</i><sub>OC</sub>) of 0.31 V and a high short-circuit current (<i>I</i><sub>SC</sub>) of 23 μA, and the high electric current (approximately\n23 μA) can be sustained for up to 120 min. The current output\nperformance of this membrane exceeds that of the pristine PSSA/PVA\nmembrane, and this work is anticipated to advance the application\nof a traditional polyelectrolyte membrane in the field of MEGs.