Tailoring the dipole properties in dielectric polymers to realize high energy density with high breakdown strength and low dielectric loss

Abstract

Articles you may be interested inAromatic poly(arylene ether urea) with high dipole moment for high thermal stability and high energy density capacitors Appl. Phys. Lett. 106, 202902 (2015); 10.1063/1.4921485Meta-aromatic polyurea with high dipole moment and dipole density for energy storage capacitors Appl. Phys. Lett. Enhanced electric breakdown strength and high energy density of barium titanate filled polymer nanocompositesHigh energy density polymer materials are desirable for a broad range of modern power electronic systems. Here, we report the development of a new class of polymer dielectrics based on polyurea and polythiourea, which possess high thermal stability. By increasing the dipole density, the dielectric constant of meta-phenylene polyurea and methylene polythiourea can be increased to 5.7, compared with aromatic polyurea and aromatic polythiourea, which have a dielectric constant in the range of 4.1-4.3. The random dipoles with high dipolar moment and amorphous structure of these polyurea and polythiourea based polymers provide strong scattering to the charge carriers, resulting in low losses even at high electric fields. Consequently, this new class of polymers exhibit a linear dielectric response to the highest field measured (>700 MV/m) with a high breakdown strength, achieving high energy density (>13 J/cm 3 ) with high efficiency (>90%). V C 2015 AIP Publishing LLC.

Optimizing nanostructure to achieve high dielectric response with low loss in strongly dipolar polymers

“…In this work, through a combined theoretical and experimental investigation, we show that such a polymer with high T g can be realized in several recently developed strongly dipolar polymers based on aromatic urea and thiourea units, with dipole moments of 4.5 Debye and 4.89 Debye, respectively, [8,[32][33][34] which are much higher than for VDF in PVDF based polymers, with the dipole moment of 2 Debye [24][25][26]. It is the free volume effect (FVE) at temperatures below T g (4200 1C) that leads to a high dielectric constant (K45.6) in meta-phenylene polyurea (meta-PU) (see Scheme 1 for the chemical structure).…”

All-Organic Cross-Linked Polysiloxane-Aromatic Thiourea Dielectric Films for Electrical Energy Storage Application

“…The Frohlich model can be used to describe the orientation polarization of polymers, including short-range interaction between molecules and deformation polarizations. In this model, the dielectric constant is proportional to the dipole moment, volumetric dipole density, and correlation factor between the dipoles . It is given as where ε r s and ε r∞ are the dielectric constants at superlow frequency and optical frequency, respectively, N is the volumetric dipole density, g is the correlation factor, p is the dipole moment, k is the Boltzmann constant, and T is the temperature.…”

Crosslinked polyarylene ether nitrile film as flexible dielectric materials with ultrahigh thermal stability

“…The demands to dielectrics for capacitor use are that the stable dielectric properties, moderate mechanical properties and great reliability in changing environment. Up to now, biaxially oriented polypropylene film (BOPP), polyethylene terephthalate (PET) and Poly(vinylidene fluoride) (PVDF) are the most widely used organic dielectric materials for energy storage film capacitors2728293031. However, BOPP, PET and PVDF based capacitor can only work at temperature lower than 150 °C due to their low glass transition temperatures ( T g ).…”