Graphene oxide-encapsulated carbon nanotube hybrids for high dielectric performance nanocomposites with enhanced energy storage density

Abstract

Polymer-based materials with a high dielectric constant show great potential for energy storage applications. Since the intrinsic dielectric constant of most polymers is very low, the integration of carbon nanotubes (CNTs) into the polymers provides an attractive and promising way to reach a high dielectric constant owing to their outstanding intrinsic physical performances. However, these CNT-based composites usually suffer from high dielectric loss, low breakdown strength and the difficulty to tailor the dielectric constant. Herein, we have designed and fabricated a new class of candidates composed of graphene oxide-encapsulated carbon nanotube (GO-e-CNT) hybrids. The obtained GO-e-CNT-polymer composites not only exhibit a high dielectric constant and low dielectric loss, but also have a highly enhanced breakdown strength and maximum energy storage density. Moreover, the dielectric constant of the composites can be tuned easily by tailoring the loading of GO-e-CNTs. It is believed that the GO shells around CNTs play an important role in realizing the high dielectric performances of the composites. GO shells can not only effectively improve the dispersion of CNTs, but also act as insulation barriers for suppressing leakage current and increasing breakdown strength. Our strategy provides a new pathway to achieve CNT-based polymer composites with high dielectric performances for energy storage applications.

Achieving significantly enhanced dielectric performance of reduced graphene oxide/polymer composite by covalent modification of graphene oxide surface

“…In addition, the chemical modification process of rGO was a one-step reaction which was facile to conduct. In the report of the composite film using carbon nanotube encapsulated in graphene as the fillers in the polyurethane matrix, a dielectric constant of about 56 and a dielectric loss of 0.12 (as opposed to 60 and 0.048, respectively in this study) at 10 3 Hz was achieved [4]. Thus, we believe the reported film herein possesses advantageous comprehensive properties and is an addition to the current choices of dielectric films with superior performances.…”

“…Polymeric flexible composite films with high dielectric constants and low dielectric losses have attracted intense research attention due to their potential applications in artificial muscles and skins, charge-storage devices, and flexible electronics [1][2][3][4][5]. The fabrication of flexible dielectric films using polymers and electric conductive fillers has proven to be a promising strategy in producing films with advantageous dielectric properties [5][6][7][8][9][10][11][12].…”

Improved dielectric permittivity and retained low loss in layer-structured films via controlling interfaces

“…Figure 3d depicts the frequency dependence of loss tangent for CNT/PVDF composites. Generally, the loss of percolative composites mainly originates from the DC conduction process, interfacial polarization, and dipole orientation [75]. For pristine PVDF, the loss is mainly induced by interfacial polarization and dipole orientation which usually occur at low frequencies.…”

Enhanced dielectric and energy storage density induced by surface-modified BaTiO3 nanofibers in poly(vinylidene fluoride) nanocomposites

“…To enhance the dielectric constants of the polymers, one route focuses on dispersing conductive fillers such as carbon black, carbon nanotubes, graphene, and nickel particles into the polymer matrix to achieve percolative composites [17][18][19][20][21][22], which have high dielectric constant in company with a large increase of dielectric loss and low breakdown strength [23]. So the percolative composites are not suitable as effective materials for high energy-storage density capacitors.…”