High-density electrostatic energy storage in a multi-layer P(VDF-TrFE-CFE)/2D mica nanocomposite heterostructure capacitor

Abstract

The growing need for renewable energy has drawn significant attention to the development of energy storage systems with ultra-high capacity and efficiency. Polymer-based dielectric capacitors are important in modern electronics and energy storage systems because of their inherent flexibility, fast charge–discharge capabilities, low dielectric loss, and high power density. However, the conflicting relationship between dielectric polarization and electric breakdown behavior frequently hinders further advancements in energy storage performance. In this study, we incorporated mechanically exfoliated 2D mica as nanofillers into a poly (vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (P(VDF-TrFE-CFE)) or PTC polymer to fabricate multilayered heterostructure capacitors and arranged them in a PTC/mica/PTC (PMP) and PTC/mica/PTC/mica/PTC (PMPMP) configuration. PMP and PMPMP nanocomposite films exhibit maximum discharged energy densities of 50 J cm⁻³ (E = 750 MV m⁻¹) and 45 J cm⁻³ (E = 625 MV m⁻¹), respectively, compared to the typical PTC capacitor with a maximum discharged energy density of 15 J cm⁻³ (E = 500 MV m⁻¹). The PMPMP capacitors demonstrate a discharge time of 6.64 μs with high cyclic stability (98%) after thousands of cycles at an applied voltage of 400 V. This study provides a comprehensive understanding of the development of polymer- and 2D nanofiller-based capacitors for industrial applications.