Concurrently Improved Breakdown Strength and Storage Energy Capacitance in the Core–Shell-Structured Aromatic Polythiourea@BaTiO₃ Polymer Nanocomposites Induced by the Nature of Interfacial Polarization and Crystallization

Abstract

Interfacial architecture of the nanofillers is the critical factor to achieve desirable dielectric properties in the polymer nanocomposites. However, a basic understanding of the role of interfacial polarization and crystallization on energy storage is very seldom. Herein, we synthesized the core−shell aromatic polythiourea@BaTiO 3 nanoparticles (ArPTU@BT NPs) as nanofillers to prepare ferroelectric polymer nanocomposites. Remarkably, direct detections of interfacial morphology, polarization, and interfacial crystallization mechanism in ferroelectric nanocomposites were revealed by a combination of atomic force microscopy (AFM) and flash differential scanning calorimetry sites (Flash DSC), which were experimentally detected by AFM, can suppress the local electric field and the migration of charges, leading to a high breakdown strength (E b ). Second, the addition of ArPTU@BT NPs, which were served as heterogeneous nucleators, can promote the crystallization rate (t 0.5 ) and form a tiny spherulite, which is beneficial for reducing the energy barrier of dipole switching and enhancing the interfacial polarization to achieve a high dielectric constant (ε) as well as an ultrahigh energy density (U). Our systematic studies provide the possibilities in understanding interfacial behaviors to design ferroelectric polymer nanocomposites for high-capacitance capacitor applications.

Regulation of Interfacial Polarization and Local Electric Field Strength Achieved Highly Energy Storage Performance in Polyetherimide Nanocomposites at Elevated Temperature via 2D Hybrid Structure

“…Dielectric capacitors are widely employed in modern electronic products and transmission electrical markets, for example, wind turbine generators, atmospheric lasers, and electromagnetic instruments. [ 1–7 ] Considering high‐temperature and high electric field condition (e.g., power converter located in or near the turbine engine >180 °C, power electronic equipment with integrated capacitor >150 °C), there is an emergent need for electrostatic capacitors capable of high‐temperature operation. [ 6–8 ] At present, biaxially oriented polypropylene (BOPP) films are considered as the mainstream polymer film capacitors on the markets.…”

“…[ 6,13–17 ] Nevertheless, the conjugated aromatic groups on these polymers’ backbones further lower the energy band gap, leading to a drastic rise in conductivity with an increment of temperature, therefore, deteriorating discharge energy density and charge/discharge efficiency. [ 5,14,18–24 ]…”

All-Organic Polymer Dielectrics Containing Sulfonyl Dipolar Groups and π–π Stacking Interaction in Side-Chain Architectures

“…However, the relative dielectric constant (ε r ) or permittivity of most commercially available polymers is too low to meet the requirements of high energy density or miniaturization of modern electronic components . In this case, different strategies are carried out to increase the ε r and energy density, such as doping inorganic fillers with high ε r (such as BaTiO 3 ) into the polymer matrix to enhance the ε r , − improving the interfacial characteristics, e.g., constructing multilayer structure − or core–shell fillers. − However, due to the large difference in ε r or conductive properties between the polymer matrix and the fillers, the concentrated local electric fields occur in the films, resulting in the decreased breakdown strength ( E b ) and the increased tan δ.…”

Regenerated Cellulose/NaNbO3 Nanowire Dielectric Composite Films with Superior Discharge Energy Density and Efficiency

“…The strategy of combining inorganic materials with polymers is a good approach. The common ceramics with high dielectric constant, such as BaTiO 3 , , Ba x Sr 1– x TiO 3 , and CaCu 3 Ti 4 O 12 , render the electric field between interfaces distorted in terms of the difference of permittivity, leading to a reduced breakdown strength. Also, the relatively high remnant polarization ends in an undesirable energy density and low efficiency.…”