PREPARATION AND DIELECTRIC PROPERTIES OF PVA AND P(VDF-HFP) ALTERNATING MULTILAYER FIBERS FOR ENERGY STORAGE APPLICATIONS

Dielectric polymer capacitors with high energy storage density are becoming increasingly important for the current advancements in electrical power applications. Energy storage performance in dielectric materials not only depends on the dielectric breakdown strength but also dielectric constant. This study focuses on the dielectric properties of polyvinyl alcohol (PVA) and poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) alternating multilayer fibers with different layers. Alternating multilayer structures layer by layer were prepared by using an electrospinning technique with suitable conditions, and the thickness of multilayer fibers was controlled by time. Alternating multilayer of P(VDF-HFP)/PVA structures can bring impressive the dielectric performance and energy storage efficiency. The morphology of obtained fibers was investigated by SEM. The dielectric properties and conductivity of multilayer fiber were investigated by using an LCR meter. The dielectric constant and conductivity of PVA and P(VDF-HFP) alternating multilayer fibers increase with the increasing number of layers. The dielectric constant of alternating multilayer fibers (8 layers) at a frequency of 20 Hz is observed to increase by 38.7% compared to PVA fibers. It appears that the integrated PVA and P(VDF-HFP) fibers, through an alternating multilayer structure, influence the interfacial polarization and the dominant charge carriers in each fiber layer. Additionally, the energy storage density of alternating multilayer fibers (8 layers) at 20MV/m is enhanced by 34.0% compared to PVA fibers.