High?temperature dielectric polymer nanocomposites with facilely prepared nanostructured Al2O3 fillers exhibit remarkable electrical energy storage and discharge capabilities at elevated temperatures and high electric fields, outperforming state?of?the?art polymer dielectrics. The significant impact of the filler morphology on conduction behavior and capacitive performance of the composites is revealed.Next?generation microelectronics and electrical power systems call for high?energy?density dielectric polymeric materials that can operate efficiently under elevated temperatures. However, the currently available polymer dielectrics are limited to relatively low working temperatures. Here, the solution?processable polymer nanocomposites consisting of readily prepared Al2O3 fillers with systematically varied morphologies including nanoparticles, nanowires, and nanoplates are reported. The field?dependent electrical conduction of the polymer nanocomposites at elevated temperatures is investigated. A strong dependence of the conduction behavior and breakdown strength of the polymer composites on the filler morphology is revealed experimentally and is further rationalized via computations. The polymer composites containing Al2O3 nanoplates display a record capacitive performance, e.g., a discharged energy density of 3.31 J cm?3 and a charge?discharge efficiency of >90% measured at 450 MV m?1 and 150 ?C, significantly outperforming the state?of?the?art dielectric polymers and nanocomposites that are typically prepared via tedious, low?yield approaches.

» Author: He Li, Ding Ai, Lulu Ren, Bin Yao, Zhubing Han, Zhonghui Shen, Jianjun Wang, Long?Qing Chen, Qing Wang

» Reference: doi:10.1002/adma.201900875

» Publication Date: 03/06/2019

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