Significantly increased energy density and discharge efficiency at high temperature in polyetherimide nanocomposites by a small amount of Al₂O₃ nanoparticles

Abstract

Polymer dielectrics with available energy storage performance at high temperatures are critical to meet the demand of the emerging applications such as hybrid electric vehicles (HEVs), wind turbine generators, and...

Ultrahigh Energy Storage Performance of Layered Polymer Nanocomposites over a Broad Temperature Range

“…Even more interestingly, the maximum U e at η > 90% of the layered composite is obtained at 310 MV m −1 , while the corresponding fields are 500 MV m −1 for PEI-DPDI (DPDI, 2,2′,9,9′-Tetrakis(1pentylhexyl)-[5,5′-bianthra[2,1,9-def:6,5,10-d′e′f′]diisoquinoline]-1,1′,3,3′,8,8′,10,10′(2H,2′H,9H,9′H)-octone) and PEI-Al 2 O 3 NPs, and 400 MV m −1 for PC-SiO 2 and c-BCB-BNNs. [2,11,28,29] Running at relatively low fields reduces operation cost and affords better reliability of high-energy-density capacitors. Moreover, as shown in the cyclic charging-discharging results of the layered composite, there is no sign of degradation of U e (<± 2.5%) over continuous 50 000 cycles operating at 150 MV m −1 and 150 °C, indicative of its great reliability (Figure 2d; Figure S22, Supporting Information).…”

“…[9,13,[19][20][21][22][23][24][25][26][27] However, as the electrical conduction increases exponentially with the increase of temperature and the applied electric field, high energy loss and large reductions in η, and discharged energy density (U e ) are found in the polymers at temperatures even well below their T g . [28][29][30] For instance, U e and η of Kapton PI with a T g of ≈360 °C drop precipitately from 1.53 J cm −3 and 95.2% at room temperature to 0.82 J cm −3 and 55.7%, respectively, as temperature rises to 150 °C. [2] More recently, the addition of inorganic fillers such as boron nitride nanosheets (BNNSs) and Al 2 O 3 nanoplates and high-electron-affinity molecular semiconductors (e.g., [6,6]-phenyl-C 61 -butyric acid methyl ester, PCBM) into the high T g polymers has been shown to effectively reduce the conduction loss and substantially improve the U e and η of the polymer composites at high electric fields and elevated temperatures.…”

“…[ 2 ] More recently, the addition of inorganic fillers such as boron nitride nanosheets (BNNSs) and Al 2 O 3 nanoplates and high‐electron‐affinity molecular semiconductors (e.g., [6,6]‐phenyl‐C 61 ‐butyric acid methyl ester, PCBM) into the high T g polymers has been shown to effectively reduce the conduction loss and substantially improve the U e and η of the polymer composites at high electric fields and elevated temperatures. [ 21,28,29,31–33 ] For example, a U e of 1.12 J cm −3 with an impressive η of 93.7% was obtained in the PI–Al 2 O 3 composites at 150 °C. [ 19 ] While substantial effort has been devoted to impeding the high‐field conduction loss of polymer dielectrics, very little attention has been directed toward the improvement of the dielectric constant ( K ) of high‐temperature polymer dielectrics in order to enhance their energy densities.…”

An Overview of Linear Dielectric Polymers and Their Nanocomposites for Energy Storage

“…Fan et al fabricated Al2O3 nanoparticle/PEI nanocomposite films by simply casting a mixed precursor solution on a glass plate, as shown in Figure 8a. The energy storage properties of blended films as a function of Al2O3 content at various temperatures were also studied [76]. Figure 8b shows the dielectric constant and dielectric loss of Al2O3/PEI blended films with varying Al2O3 volume content.…”

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 ).…”