Tuning interfacial relaxations in P(VDF-HFP) with Al2O3@ZrO2 core-shell nanofillers for enhanced dielectric and energy storage performance

Abstract

High energy density is a desirable index for advanced energy storage materials. Here, core-shell structured nanoparticles Al2O3@ZrO2 (A@Z) are synthesized to fabricate P(VDF-HFP)/A@Z nanocomposite films. Experimental and simulation results confirm that A@Z nanoparticles are effective in suppressing the local electric field distortion of nanocomposites, as well as intensifying the interfacial polarization without affecting the intrinsic orientational polarization. The activation energy of the interfacial relaxation in crystalline/amorphous region is increased from 0.96 eV of the neat P(VDF-HFP) to 1.25 eV of P(VDF-HFP)/5 vol%-A@Z nanocomposite. Meanwhile, a new dielectric relaxation with energy of ∼1.08 eV related to nanoparticles/amorphous phase of P(VDF-HFP) is induced. The modulated interfaces present substantial capability in inhibiting charge motion, which contributes to an improved electrical property and energy density of the nanocomposites. Specifically, a ∼200% enhancement in discharged energy density is achieved in the P(VDF-HFP)/5 vol%-A@Z nanocomposite, demonstrating a promising dielectric material choice for energy storage capacitor applications.