Enhanced Breakdown and Energy Storage Performance of Capacitor Films via Heterogeneous Nucleation and High-Temperature Annealing.

Currently, thin-film capacitors are widely used in consumer electronics, renewable energy systems, and power electronics owing to their excellent electrical properties. However, with increasing requirements for high integration and high energy storage densities, thin-film dielectricsthe core component of thin-film capacitorsare facing increasingly stringent requirements. The low dielectric constant and insufficient breakdown strength of polypropylene (PP) dielectrics, which account for more than 50% of the thin-film dielectric market, are their major limitations. In this regard, this study proposes the use of hexagonal boron nitride (h-BN) with a slightly higher dielectric constant than that of PP as a heterogeneous nucleating agent to prepare composite dielectric materials for improving the electrical properties and thermal stability of PP. The addition of a small amount of hexagonal-boron nitride nanoparticles (0.35 vol %) as an inorganic filler to the PP matrix is shown to increase the dielectric constant of PP films from 2.2 to 2.7, while the energy storage density increases drastically from 5.36 J/cm for pure PP films to 11.35 J/cm for the PP nanocomposite films. The significant improvement in the energy storage properties of the h-BN/PP nanocomposite films shows that the addition of h-BN to PP-based films can help in the development of capacitors with high energy densities.