Largely enhanced dielectric properties of polymer composites with HfO2 nanoparticles for high-temperature film capacitors

Abstract

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High‐Temperature High‐Energy‐Density Dielectric Polymer Nanocomposites Utilizing Inorganic Core–Shell Nanostructured Nanofillers

“…The amorphous nature of the Al 2 O 3 shell is verified by the X-ray diffraction (XRD) as shown in Figure S2, Supporting Information, in which the Al 2 O 3 @ ZrO 2 -1 nanoparticles show no additional characteristic peaks other than monoclinic ZrO 2 . PEI, which has been identified as the best high-temperature dielectric polymer in our earlier work, [18][19][20] was selected as the matrix. A series of the PEI-based nanocomposites consisting of unmodified ZrO 2 and core-shell Al 2 O 3 @ZrO 2 nanoparticles were prepared via a facile solution casting method (Figure S3, Supporting Information).…”

“…The development of high-energy-density dielectric materials is fueled by the need for capacitive energy storage devices in highly the high-temperature polyetherimide (PEI) composites loaded with the core-shell structured nanoparticles composed of ZrO 2 core and Al 2 O 3 shell. The encapsulation of ZrO 2 with Al 2 O 3 establishes a gradient of the K values (i.e., ≈25 of ZrO 2 , [26] ≈7.9-10 of Al 2 O 3 , [26] and ≈3.2 of PEI [18][19][20] ) in the nanocomposites, which is conducive to the breakdown strength of the composites. The large divergence in K of ceramic fillers and polymer is known to aggravate the local distortion of electric field and yield highly inhomogeneous field distribution, and consequently, greatly reduce the breakdown strength of the composites.…”

“…[11][12][13][14][15] For example, the operation temperature of biaxially oriented polypropylene (BOPP), the industrial benchmark dielectric polymer, is well below 105 °C under the applied electric fields. [15] A variety of innovative approaches, including the incorporation of wide bandgap inorganic fillers, [16][17][18] deposition of ceramic coatings onto polymer films, [19][20][21] addition of high-electronaffinity molecular semiconductors, [22] and utilization of multilayer-structured films, [23][24][25] have been developed to improve the high-temperature capacitive performance of dielectric polymers. While these approaches are effective in hindering electrical conduction and reducing energy loss at high fields and elevated temperatures, the energy densities of the current high-temperature dielectric composites are limited (below 4 J cm −3 in most cases) owing to relatively low dielectric constant (K) values of the fillers, such as ≈3.5-4 of SiO 2 and boron nitride nanosheets (BNNSs) [16,26] and ≈7.9-10 of Al 2 O 3 .…”

Dielectric polymers for high-temperature capacitive energy storage

“…Recently, breakthrough results have been achieved by using wide bandgap inorganic fillers to inhibit charge injection and conduction in polymers. 6,61,[67][68][69][70][71][72][73][74][75] The resulting dielectric polymer composites exhibit remarkable capacitive performance at high temperatures, far exceeding the current dielectric polymers. Different from prior reviews covering the high-temperature dielectric polymer composites, 47,48,58,59,[76][77][78][79] this article exclusively focuses on the recent innovations in all-organic dielectric polymers that are designed for capacitive energy storage applications at high electric field and high temperature (i.e., ≥ 200 MV m -1 and ≥ 120 °C ).…”

2D MoS2 Nanosheet‐Based Polyimide Nanocomposite with High Energy Density for High Temperature Capacitor Applications

“…[29] Ren et al reported a nanocomposite consisting of a PEI substrate with hafnium oxide (HfO 2 ) nanoparticles to achieve an energy density of 2.82 J cm −3 at 150°C. [30] A hightemperature dielectric energy storage material was prepared by adding montmorillonite (MMT) nanosheets to the PAI polymer, which exhibited an energy density of 3.6 J cm −3 at a temperature of 150°C. [31] Polyimide (PI) is a plastic widely used in the engineering field.…”