Dielectric properties and energy‐storage performance of two‐dimensional molybdenum disulfide nanosheets/polyimide composite films

Abstract

Flexible dielectric materials with high electric energy density and high‐temperature resistant characteristic are of great importance for modern electronics and electrical systems. Herein, two‐dimensional molybdenum disulfide (MoS2) nanosheets were efficiently produced via liquid‐phase exfoliation and then incorporated into polyimide (PI) to prepare MoS2/PI dielectric nanocomposites. Compared to the pristine PI, MoS2/PI nanocomposite films exhibited much larger dielectric permittivity while their dielectric losses still maintained relatively low levels. On the other hand, the Weibull breakdown strength of these nanocomposite films initially increased and then decreased with the increase in the MoS2 content and gave rise to a maximum value of 395 MV m−1 at 1 vol % loading. Combination of the improved dielectric permittivity and breakdown strength makes the MoS2/PI nanocomposite film with 1 vol % MoS2 possess an elevated energy density of about 3.35 J cm−3. Moreover, good tensile and thermal properties of the nanocomposite films hold great promise for their applications in high‐temperature and harsh conditions. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47991.

Low‐content metal‐organic framework enhanced interface effect to improve the insulation properties of polyimide‐based composite films

“…The above results indicate that UiO‐66/PI composites can enhance E b through highly efficient 3D interface effect. Here, to demonstrate the scientific and advanced nature of the strategy of MOFs doping to form highly efficient interface effects to enhance E b , we compared E b of PI‐matrix composites with different dimensional filler doping 34–46 . These studies are advanced strategies (such as introduction of zero‐dimensional, one‐dimensional and two‐dimensional fillers, mixing of different dimensional fillers, and multi‐layer structural designs) that have been published in recent years and are widely accepted.…”

Fabrication of BaTiO3-Loaded Graphene Nanosheets-Based Polyarylene Ether Nitrile Nanocomposites with Enhanced Dielectric and Crystallization Properties

“…Polyarylene ether nitrile (PEN), a kind of high-performance thermoplastic aromatic polymer, shows high heat resistance, flame retardancy, radiation resistance, excellent mechanical strength, outstanding flexibility and formability [14][15][16][17]. In addition, PEN still has significant advantages over other thermoplastic resins such as thermoplastic polyimide (TPI) [18] and polyetheretherketone (PEEK) [19], including low processing temperature (~280 °C), high temperature resistance (>450 °C) and short molding time (0.5~1 h), and these advantages are beneficial for processing PEN into various forms to meet the dielectric applications. In this work, barium titanate@zinc phthalocyanine/graphene oxide (BT@ZnPc-GO) nanoparticles with different GO contents were firstly prepared by electrostatic adsorption between BT@ZnPc and GO nanoparticles with the action of calcium ion, and the obtained nanoparticles are characterized in detail.…”

High-Temperature Polyimide Dielectric Materials for Energy Storage

“…At 30 wt% mBN, the mBN/PI composite material exhibited a high ε r (3.77) and low dielectric loss (0.007); the material also showed good thermal stability (λ = 0.696 W m À1 K À1 ), a high temperature index (279°C), and T g was 240°C [24]. Cheng et al [25] considered that molybdenum disulfide (MoS 2 ) had an appreciable band gap and excellent heat resistance, and prepared MoS 2 /PI nanocomposite films. Compared with the pure PI film, the ε r of the composite film was significantly increased, while the dielectric loss remained relatively low.…”

“…At a filler content of 1 vol%, the breakdown field strength reached 395 MV m À1 , while U e increased to ≈3.35 J cm À3 . Furthermore, at 395 MV m À1 , the charge and discharge efficiency could still be maintained above 80% [25]. Alumina (Al 2 O 3 ) filler has good insulation performance, high thermal conductivity, and is relatively inexpensive.…”