Flexible Graphene Oxide-Based PVP/PVA Composite Films for Dielectric Energy Storage Applications

Sustainable energy storage solutions are essential for decreasing our reliance on fossil fuels, which are becoming less accessible, and for creating an environmentally friendly energy future. Flexible and stretchable high-dielectric-constant energy storage materials are an emerging technology aimed at developing reliable, compact, and highly efficient storage solutions that are also lightweight and miniaturized. A series of flexible, high-dielectric-constant graphene oxide (GO) based composite films has been prepared using a blend of polyvinylpyrrolidone and polyvinyl alcohol (PVPA) via solution casting. Polyvinyl alcohol (PVA) offers high flexibility and good mechanical strength, while polyvinylpyrrolidone (PVP), being a polar polymer, enhances interfacial polarization. GO, as a polarizable filler, can form associations through oxygen-containing groups with the polar regions of the PVPA matrix, creating excess sites for charge accumulation necessary for high dielectric constants, based on the Maxwell–Wagner–Sillars (MWS) effect. GO content has varied from 0.1 to 0.7 wt%. The synthesis of GO and PVPA/GO composites has been confirmed using UV–Visible and FTIR spectroscopy. Dielectric constants were measured across a broad frequency range for the series of composites. The relationship between the dielectric constant and GO content depends heavily on the frequency of the electric field, suggesting that multiple polarization and relaxation mechanisms influence the dielectric constant’s value. The maximum increase observed was 34% at 40 Hz when 0.7 wt% GO was incorporated, which is promising and desirable for flexible high-k capacitor dielectrics aimed at advancing efficient and sustainable energy storage solutions.