Polyamideimide dielectric with montmorillonite nanosheets coating for high-temperature energy storage

• MMT nanocoatings were prepared on dielectric Kapton films by a versatile dip-coating method. A high energy density of 2.9 J cm ?3 with an efficiency higher than 80% was achieved at 150 °C. The charge blocking/regulating effect revealed high-field characterization and finite element simulation. To meet the ever-increasing demand for electric power storage conversion under harsh environment, polymer dielectrics, as functional component in electrostatic capacitors, are required to serve temperatures. However, it is challenging maintain favorable electrical insulation dielectrics temperature rise because conduction loss elevated temperature, which will lead reduced breakdown strength, density, service life. Here, surface engineering method presented enhance high-temperature performance via montmorillonite (MMT) nanosheets. At °C, significantly enhanced strength 551MV/m coated polyamideimide (PAI) optimized coating thickness content, resulting charge-discharge >80% that outperform existing polymers polyimide-based composites. Finite simulation demonstrates this superior attributed anisotropic properties nanosheets, not only blocks charges injected from electrodes but also regulates transport dissipate along in-plane direction. This work offers scalable approach enabling wide range dielectrics.