P(VDF-TrFE) nanocomposite thin films with cellulose nanofibers and dopamine-modified BaTiO₃ nanoparticles for enhanced energy storage

Abstract

Fluoropolymers, known for their high dielectric permittivity, are extensively studied for nanocomposite energy storage. However, nanoparticle incorporation introduces defects, making the fabrication of thin films able to withstand high electric fields challenging. Consequently, research on films thinner than 10 µm remains limited, despite their potential for effective polarization at lower voltages. Among fluoropolymers, P(VDF-TrFE) offers well-established and easy thin film deposition via spin coating, making it ideal for nanocomposite thin films. This study presents the synthesis and energy storage characterization of P(VDF-TrFE) nanocomposite thin films with a thickness of ∼1 µm, demonstrating enhanced energy storage performance. This is achieved by adding a nanoparticle mixture of carboxymethyl cellulose nanofibers and polydopamine-coated BTO into the P(VDF-TrFE) polymer matrix, resulting in a 60% increase in energy density and a twofold enhancement in energy efficiency. A direct correlation between the nanoparticle concentration and the observed enhancements in dielectric and ferroelectric characteristics is established.