Optimizing Ply Pattern and Composition of Layered Composites based on Cyanate Ester, Carbon Nanotube, and Boron Nitride: Toward Ultralow Dielectric Loss and High Energy Storage

Abstract

High dielectric loss and low breakdown strength have been two bottlenecks restricting applications of conductor/polymer composites for high energy storage. Herein, three kinds of layered composites, named BC, BCB, and CBC, were fabricated through stacking up hexagonal boron nitride (hBN)/cyanate ester (CE) (B layer) on carbon nanotube (CNT)/CE with 0.4 wt % CNTs (C layer). The effects of ply pattern and composition on dielectric properties, breakdown strength, and energy density of composites were investigated and also compared with those of single-layer 0.4CNT/CE composite containing 0.4 wt % of CNTs. Results show that three kinds of layered composites have significantly reduced dielectric loss and improved breakdown strength and energy density. Especially, for the CBC composite with 20 wt % hBN in B layer (C20BC), its dielectric constant is as high as 323 (100 Hz) and retains a value larger than 270 (1–103 Hz), it is the highest value reported so far among multilayered composites based on conductor/polymer and insulating layers; moreover, its breakdown strength and energy density are about 1.5 and 25 times of that of 0.4CNT/CE composite, respectively. Note that C20BC composite has very low dielectric loss (0.049 at 100 Hz) or much less at increased frequencies (>100 Hz), only about 2.6 × 10–3 times of that at 100 Hz of 0.4CNT/CE composite. The origin behind these attractive properties was intensively discussed.

An overview of boron nitride based polymer nanocomposites

“…The melt casting and spin coating methods were successfully used to fabricate novel layered structure composites comprised of CNT/CE and h‐BN/CE. [ 190 ] Three types of layered composites namely BC, BCB, and CBC, were synthesized through loading up of hexagonal boron nitride (h‐BN)/cyanate ester (CE) (B layer) on carbon nanotube (CNT)/CE with 0.4 wt% CNTs (C layer) (Figure 18). The breakdown strength, energy density and dielectric properties of these composites were investigated and compared with those of single‐layer 0.4CNT/CE composite containing 0.4 wt% of CNTs.…”

Preparation and application of dielectric polymers with high permittivity and low energy loss: A mini review

“…Modified CNT‐based composites were also reported. For example, Lu et al 87 published a work about a novel composites with multilayered structured: carbon nanotubes (CNT)/cyanate (CE)/hexagonal boron nitride (hBN). This method achieved an ultra‐low dielectric loss and an increased DBS and energy density with only 0.4 wt% of CNTs.…”

Improved Mechanical, Anti-UV Irradiation, and Imparted Luminescence Properties of Cyanate Ester Resin/Unzipped Multiwalled Carbon Nanotubes/Europium Nanocomposites

“…Multiwalled carbon nanotubes (MWCNTs) have excellent structural characteristics, are easy to functionalize, and can be used as reinforcement materials to improve the performance of polymer materials [ 8 , 9 , 10 , 11 ]. CER/MWCNTs nanocomposites have been recently developed and studied by several teams [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ]. The catalytic effect of MWCNTs on CER polymerization was fixed, and CER/MWCNTs nanocomposites with improved mechanical and thermal properties and electrical and thermal conductivity have been elaborated.…”