Yue Dong, Zhang Wenchao, Wang Puzhen, Zhang Yong, Teng Yu, Yin Jinghua, Feng Yu
Key Laboratory of Engineering Dielectrics and Its Application, Ministry of Education, Harbin University of Science and Technology, Harbin, 150080, P.R. China.
School of Electrical and Electronic Engineering, Harbin University of Science and Technology, Harbin, 150080, P.R. China.
Mater Horiz. 2024 Feb 6;11(3):726-736. doi: 10.1039/d3mh00907f.
Enhancing the high electric field resistance and energy storage capacity of polymer dielectrics has been a long-standing challenge for the iterations of power equipment. Synergistic inhibition of carrier injection and transport is vital to energy storage performance improvement. Herein, promising polymer polyetherimide (PEI) was employed as a matrix and wider bandgap boron nitride nanosheets (BNNSs) were used as a reinforcing filler. Utilizing high-throughput stochastic breakdown simulations with the distribution characteristics of BNNSs as parameters, a series of topological gradient structures with the potential to enhance performance were obtained, thereby shortening the experimental cycle. Changing the BNNS distribution of symmetric/asymmetric and positive/inverse gradients, as well as the total and gradient contents of BNNSs, means that the position and condition of the surface barrier layer and central hinder layer change, which influences the energy storage performance of the polymer at room temperature and high temperature. Remarkably, the asymmetric gradient structure composite dielectrics exhibited excellent performances. Among them, the PEI-based composite dielectric with 2 vol% BNNS asymmetric inverse gradient distribution (gradient content of 1 vol%) achieved energy densities of 8.26 and 4.78 J cm at room temperature and 150 °C, respectively. The asymmetric gradient structure design strategy holds great promise for optimizing the energy storage capacity of polymer dielectric capacitors.
提高聚合物电介质的高电场抗性和储能容量一直是电力设备迭代面临的长期挑战。协同抑制载流子注入和传输对于改善储能性能至关重要。在此，选用了有前景的聚合物聚醚酰亚胺（PEI）作为基体，并使用宽带隙氮化硼纳米片（BNNSs）作为增强填料。以BNNSs的分布特性为参数，利用高通量随机击穿模拟，获得了一系列具有性能增强潜力的拓扑梯度结构，从而缩短了实验周期。改变对称/不对称和正/反梯度的BNNS分布，以及BNNSs的总量和梯度含量，意味着表面势垒层和中心阻碍层的位置和条件发生变化，这会影响聚合物在室温和高温下的储能性能。值得注意的是，不对称梯度结构复合电介质表现出优异的性能。其中，具有2 vol% BNNS不对称反梯度分布（梯度含量为1 vol%）的PEI基复合电介质在室温和150℃下的能量密度分别达到8.26和4.78 J/cm³。不对称梯度结构设计策略在优化聚合物介电电容器的储能容量方面具有很大的前景。
