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

Abstract

With the development of electrical vehicles and power electronics, the demand for high-temperature energy storage capacitors with high energy density has grown rapidly. In this investigation, 2D MoS 2 nanosheets are coated with a thin layer of poly(methyl methacrylate) and then mixed with polyimide (PI) solution to fabricate nanocomposites. The dielectric constant of MoS 2 -g-PMMA/PI (MPP-3%) reaches 4.2, which is 20% higher than that of a pristine PI film. The energy density of the MPP-3% nanocomposite reaches 8.6 J cm −3 , which is 40% higher than the highest energy density of a pristine PI film. In addition, the electric breakdown field of the MPP-3% composite is 50% higher than that of the MoS 2 /PI nanocomposite without a surface coating. Furthermore, it is found that the highest energy density of MoS 2 -g-PMMA/PI reaches 3.92 J cm −3 , which is 47.9% higher than that of the PI film at 150°C. The charge-discharge efficiency of the nanocomposite film reaches 61.7% at 150°C. This result is much higher than the previously reported research results for high-temperature capacitor applications. The MoS 2 -g-PMMA/PI-based nanocomposite shows great promise for use in high-temperature capacitor applications.

Ultralow-Content (Bi0.5Na0.5) TiO3–NaNbO3/PVDF-HFP Nanocomposites for Ultrahigh-Energy-Density Capacitor Applications

“…Previously, a large volume percent of nanofillers was added to a polymer matrix to improve the dielectric constant of the nanocomposites. , However, the defects introduced by nanoparticles always cause the nanocomposites to have a much lower breakdown field. The gradient of the dielectric constant around the organic–inorganic interface may cause a high electric field distribution around the interface.…”

Enhanced High-Temperature Capacitive Performance of a Bilayer-Structured Composite Film Employing a Charge Blocking Layer

“…Figure a illustrates the comparison of U e and η of PI/BNNS film with reported PI dielectric materials, including intrinsic PI, , PI nanocomposites, − all-organic PI composites, ,, multilayer-structured PI composites, , and PI composites containing inorganic layer. ,,− The blue, gray, yellow, purple, and green boxes are used to classify the above materials on the right of Figure a. It is found that the PI/BNNS film achieves the maximum U e when η is greater than 90%, which is far superior to the reported PI-based dielectric materials at different temperatures.…”

Biodegradable Poly(l-Lactic Acid) Films with Excellent Cycle Stability and High Dielectric Energy Storage Performance

“…To better evaluate the dielectric energy storage performance of the studied α-PLLA polymers, U rec at η > 90% is compared to commercial dielectric polymers, ,− as summarized in Figure d. It is of particular significance that the U rec of 5.7 J/cm 3 at η > 90% achieved in the α-PLLA film is excellent among these commercial dielectric polymers. ,− In particular, the reliability of the α-PLLA film is tremendously crucial for its applications. Therefore, cyclic charge–discharge experiments were carried out at room temperature and 85 °C under 200 MV/m.…”