Novel dielectric films with high energy density

Capacitive energy storage devices are essential components in modern electronics for power conditioning, conversion and renewable integration. The state-of-the-art bi-axially oriented polypropylene dielectric film has a breakdown strength of >730 MV/m and low dielectric loss of <;0.0002 at 1kHz, but suffers a low dielectric constant of 2.2. Rational development of high permittivity polymers is undertaken with the guidance of a high throughput, first principles computation-based polymer design space search engine, parallelized with chemical synthesis and high field electrical characterizations. Further understanding of the correlation between materials´ molecular and microscopic structures and electrical characteristics under high fields is essential to the rational design of new dielectric materials. In this paper, the electrical characteristics of a newly synthesized thiourea-etheramine copolymer with a dielectric constant of 5.5 were systematically investigated by a combination of broadband dielectric spectroscope, modified Sawyer-Tower polarization loop tester and pre-breakdown conduction measurements, to provide critical feedback for the rational design of polymers with high dielectric constant and low loss.