Enhanced High-Temperature Capacitive Performance of a Bilayer-Structured Composite Film Employing a Charge Blocking Layer

Abstract

The great development potential of polymer dielectric capacitors in harsh environments urgently requires enhancing capacitive performance at high temperatures. However, the exponentially increased conduction loss at high temperature and high field results in a drastic drop in energy density and charge–discharge efficiency. Here, a bilayer-structured polyimide (PI) composite film containing a wide-band gap inorganic layer as a charge blocking layer is designed. The inorganic layer improves the charge trapping ability and regulates the charge mobility at the electrode/dielectric interface. The charge injection mechanism in the interface-optimized PI/boron nitride nanosheet (BNNS) composite films is investigated by finite element simulation, and the effect of the BNNS layer on high temperature conduction is further understood. An appropriate thickness of the charge blocking layer establishes an effective energy barrier. Therefore, the composite films exhibit significantly suppressed conduction loss and excellent capacitive performance at a high temperature. A high energy density of 4.37 J cm–3 with efficiency of 92% is obtained at 200 °C and 500 MV m–1, which is superior to reported high-temperature dielectric polymers and their composite films. This work provides a promising approach to improve the energy storage performance of polymer materials at high temperatures.

Superior capacitive performance achieved in wide HOMO–LUMO gap cyanoethyl cellulose nanocomposites via forming a built-in electric field

“…Based on organic/inorganic composites, the lower defect content favors the stability, and the excellent stability performance of 0.2 wt% BFO@AO/CRC films confirmed its outstanding compatibility between the filler with the polymer, as shown in Fig. 4d 7,37–43 A considerable power density and ideal charge/discharge rates allow electrostatic capacitors to be used in electromagnetic artillery, high-voltage cables, and other applications. Fast charge–discharge tests of CRC and its nanocomposites were performed at 180 MV m −1 DC voltage, as shown in Fig.…”

Scalable High‐Permittivity Polyimide Copolymer with Ultrahigh High‐Temperature Capacitive Performance Enabled by Molecular Engineering

“…It should be noted that the copolymer films are only synthesized using conventional commercial monomers. Compared with the other high temperature polymers by using external components, such as making nanocomposites or multi-layer structures, [5,15,17,23,41,43,53,[57][58][59][60][61][62][63][64][65][66] the flexible copolymer film is compatible with the industrial production line of current commercial polymer films and has the potential to be applied in hightemperature environments of electric vehicles, power electronics, and other systems.…”

Enhancing Comprehensive Performance via Capturing and Scattering the Carriers inside PESU-Based Nanocomposite Film Capacitors

“…Polymer film capacitors, as one of the core components in modern electronic devices and electronic circuits, possess excellent characteristics such as low loss, self-healing, and microsecond-level charge/discharge rates. − Large-scale applications in various fields (e.g., healthcare security, transportation, national defense) are placing higher demands on the new generation of dielectric capacitors, i.e., requiring dielectric polymers capable of operating stably in coordination with high electric fields and high temperatures. − For example, in the aviation and aerospace fields, electronic component devices need to be placed near engines (200–300 °C). High-temperature operating environments would lead to many electronic devices equipping with additional cooling devices .…”