Jackson State University,
Keywords: polymer nanocomposite, 2D nanofillers, dielectric constant, energy density, breakdown strength
Summary:Developing a thin polymer based dielectric film with improved dielectric constant and breakdown voltage is one of the emerging fields of interest to create next generation high power density energy-storage device. Here, we report remarkably enhanced dielectric constant and energy density of a polymer nanocomposite, Polyvinylidene fluoride (PVDF) with incorporated an exfoliated layered 2D dielectric crystals Mica or h-BN in a stratified heterostructure layered geometry. The dielectric constant of this structure shows ~100% enhancement over the pristine PVDF based polymer, achieved using an ultra-low loading (~1 vol%) of 2D nanofillers. A dramatic enhancement of breakdown voltage is also measured in these 2D interfaced polymer heterostructure capacitor (1200 V/µm) compared to the pristine polymer heterostructure film (560 V/µm). We observed an energy density as high as 75 J/cm3 from the 2D-Mica interfaced polymer heterostructure, which is the highest among the observed energy density of the polymer-nanocomposite based dielectrics. Computational study using density function theory supports the experimental finding. The results demonstrate a new horizon for high energy density and breakdown voltage thin film capacitor. This work will provide basic understanding to achieve thin film based high-density energy storage capacitor devices using low-cost polymer nanocomposites for myriads of potential applications in electronics.