Excellent Stability in Polyetherimide/SiO2 Nanocomposites with Ultrahigh Energy Density and Discharge Efficiency at High Temperature. Issue 28 (13th June 2022)

• Record Type: Journal Article
• Authors: Sun, Binzhou; Hu, Penghao; Ji, Xumin; Fan, Mingzhi; Zhou, Le; Guo, Mengfan; He, Shan; Shen, Yang
• Is Part Of: Small. Volume 18:Issue 28(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-06-13
• Subjects: energy density -- energy efficiency -- high temperature -- polyetherimide -- polymer nanocomposites; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.202202421
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: Polymer dielectrics with excellent thermal stability are the essential core material for thin film capacitors applied in a harsh‐environment. However, the dielectric and mechanical properties of polymers are commonly deteriorated with temperature rising. Herein, polyetherimide (PEI)‐based nanocomposites contained with SiO2 nanoparticles (SiO2 ‐NPs) are fabricated by a solution casting method. It is found that the introduction of SiO2 ‐NPs decreases the electric conductivity and significantly enhances the breakdown strength of the nanocomposites, especially under high temperatures. As a result, the 5 vol% PEI/SiO2 ‐NPs nanocomposite film displays a superior dielectric energy storage performance, e.g., a discharged energy density of 6.30 J cm ‐3 and a charge–discharge efficiency of 90.5% measured at 620 MV m ‐1 and 150 °C. In situ scanning Kelvin probe microscopy characterization indicates that the charge carriers can be trapped in the interfacial regions between the polymer matrix and the SiO2 ‐NPs till the temperature reaches as high as 150 °C. This work demonstrates an effective strategy to fabricate high‐temperature dielectric polymer nanocomposites by embedding inorganic nanoparticles and provides a method for directly detecting charge behavior at the nanoscale inside the matrix. Abstract : Polymer dielectrics for thin film capacitors applicable for high temperature are urgently needed. Polyetherimide (PEI)‐based nanocomposite films containing SiO2 nanoparticles (SiO2 ‐NPs) are prepared by solution casting. Observed by scanning Kelvin probe microscopy, the moderate aggregated SiO2 ‐NPs effectively trap the charge carriers, especially under high temperature, which maintains high breakdown strength for the nanocomposite to achieve excellent energy storage performances.