Temperature influence on dielectric energy storage of nanocomposites

Abstract

The demand for high energy density dielectric capacitor devices is increasing due to their significant role in stationary power systems, mobile devices and pulse power applications. The polymer film based dielectric capacitor is still one of the most widely used energy storage devices owing primarily to its high energy density and low cost. To further enhance the energy density, high dielectric constant ceramic inclusions have been embedded into the polymer matrix; however, the relationship between temperature and energy density has not yet been fully investigated. Therefore, in this paper, a commonly used composites with barium titanate (BaTiO3) nanoparticles embedded in polyvinylidene fluoride (PVDF) matrix were fabricated using a solution casting method in order to explore their energy densities within a temperature range from 20°C to 120°C. Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) were used for material morphology and crystal structure characterization. Capacitance and breakdown strength were measured throughout the temperature range in order to determine the energy density of the samples with 10%, 20%, 30% and 40% volume fractions. It is found that nanocomposites with 30% volume fraction displayed the highest energy density of 5.79J/cm3 at 50°C.