Wide-bandgap fluorides/polyimide composites with enhanced energy storage properties at high temperatures

Regulation of Interfacial Polarization and Local Electric Field Strength Achieved Highly Energy Storage Performance in Polyetherimide Nanocomposites at Elevated Temperature via 2D Hybrid Structure

“…As shown in Figure 3e, the superb U d (4.09 J cm -3 at 150 °C and 400 MV m -1 ) surpasses not only these pristine polymers (e.g., PEI ≈0.48 J cm -3 , PI ≈0.73 J cm -3 , and PC ≈0.8 J cm -3 ) but also the most of the polymer-based composite films (e.g., sandwich-structured BNNS/PC/BNNS ≈2.1 J cm -3 , PEI/BT NP/BNNS ≈1.5 J cm -3 , and BN/c-DPAEK composites ≈2.5 J cm -3 ). [38,39,41,[49][50][51][52][53][54][55][56][57] Furthermore, BNNSs-TiO 2 /PEI nanocomposites display exceptional cycling stability under high temperature and high applied electric field, as presented in Figure 3f. No sign of degradation of U d (≈1.61 J cm -3 ) and η (≈91.3%) is observed over a straight 10, 000 cycles at 250 MV m -1 and 150 °C, which makes corresponding nanocomposites bright in inverters for hybrid and electric vehicles and power electronic equipment with an integrated capacitor.…”

“…where σ, σ 0 , K B , e, and T mean the volume electric conductivity, perfector, Boltzmann constant, carriers, and absolute temperature, respectively. [54][55][56][57][58] The relationship between the nature log of electric conductivity and the reciprocal of temperature (1000/T) at 100 MV m -1 of the composites is presented in Figure 4e. Compared with neat PEI, activation energy A a of composites is improved through loading 2D BNNSs-TiO 2 and BNNSs fillers (e.g., 0.23 eV of pristine PEI, 0.26 eV of BNNSs-TiO 2 /PEI composites, and 0.29 eV of BNNSs/PEI composites).…”

Enhanced high-temperature energy storage properties of polymer composites by interlayered metal nanodots

“…The TSDC data can be obtained using the half-width method. 44,[51][52][53] The trap energy level was determined as follows:…”

“…The TSDC data can be obtained using the half-width method. 44,51–53 The trap energy level was determined as follows:where T p denotes the peak-current temperature and Δ T is the temperature difference for the half-height peak. The trapped charge quantity corresponding to the trap energy level can be calculated as follows:where I ( T ) represents the TSDC curve, T 0 is the starting temperature of the peaks, T 1 is the ending temperature of the peaks, and ν is the heating rate after a short circuit.…”

Polyimide Nanodielectrics Doped with Ultralow Content of MgO Nanoparticles for High-Temperature Energy Storage

“…In this regard, nanodielectric strategies incorporating wide-bandgap ( E g ) nanofillers are advantageous, since they can not only successfully inhibit the leakage current in the polymer matrix under high electric fields and elevated temperatures, but also have flexible designability and good compatibility with existing manufacturing technology [ 21 , 22 , 23 ]. To date, the two most studied nanofillers are boron nitride nanosheets (BNNSs, E g = 5.9 eV) and alumina (Al 2 O 3 , E g = 8.6 eV), while attempts using other wide-bandgap inorganic fillers are quite limited [ 24 , 25 , 26 ]. Since magnesium oxide (MgO) features a large bandgap of 7.8 eV and a high dielectric constant of 9.7, it is reasonable to believe that its introduction can benefit both the dielectric constant and the breakdown strength of the polymer nanodielectrics [ 27 ].…”