High energy-storage density polymer-matrix dielectric composite with sandwich structure and preparing method thereof

Abstract

The invention provides a preparing method for a high energy-storage density polymer-matrix dielectric composite with a sandwich structure by using boron nitride nanosheets and copper calcium titanatenanofibers as functional fillers. The preparing method comprises the steps that the copper calcium titanate nanofibers are prepared through the electrostatic spinning technology or a hydrothermal method, and the boron nitride nanosheets are obtained through liquid-phase ultrasonic stripping; then, the copper calcium titanate nanofibers and the boron nitride nanosheets are dispersed in a polymer matrix uniformly through a solution dispersion method or a melt blending method, and thus thin films are prepared; and the copper calcium titanate fiber composite thin film is used as an intermediate dielectric layer, the boron nitride composite thin film is placed on the outer side, hot-pressing treatment is conducted, and thus the composite with the sandwich structure is prepared. According to thepreparing method, by introducing high-insulativity boron nitride as a withstand voltage layer, the breakdown strength of the composite is improved by a large margin; by adding high dielectric ceramiccopper calcium titanate, the dielectric performance of the composite is further strengthened, and accordingly the energy storage density of the composite is overall improved; and the prepared composite is mainly applied to a dielectric layer in a thin-film capacitor for improving the energy storage performance of the thin-film capacitor.

Description

technical field [0001] The application belongs to the field of dielectrics, and in particular relates to high-energy-storage-density dielectric materials, which are the key to preparing high-performance film capacitors. Background technique [0002] In modern society, countless electronic devices are used in all aspects of life. No matter for portable electronic products, or electric vehicles, or even large-scale power grid systems, a small, low-cost, high-performance energy storage device is very necessary. As the most commonly used energy storage element, film capacitors can perform rapid charge and discharge, can withstand high voltage, have high power density, can be recycled, and have stable performance. They play a vital role in the field of power systems and electronic devices. important role. High energy storage density dielectric capacitors can be used in high-load working environments such as hybrid vehicles, electromagnetic weapons, pulse energy supply equipment...

AI Technical Summary

Problems solved by technology

BOPP has an ultra-high breakdown field strength (about 600MV / m), but its low dielectric constant (about 2) restricts its overall performance, making its final energy storage density only 1-2J / cm 3

However, the general inorganic ceramic polymer composite film, due to the large filler content, will cause too many defects inside the material, so that it is impossible to take into account the dielectric constant and breakdown field strength at the same time. At the same time, too much filling of inorganic ceramics will greatly increase the cost. Improvement, not conducive to mass production and promotion

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