Giant energy storage and dielectric performance in all-polymer nanocomposites

Giant energy storage and dielectric performance in all-polymer nanocomposites

Summary

The paper reports an all-polymer nanocomposite — notably a 50/50 wt% blend of PBPDA (or PPMDA variants) and PEI — that delivers a large dielectric constant (K ≈ 13.5 for the 50/50 blend versus K ≈ 3.3 for neat PEI or PBPDA) and exceptional high-temperature capacitive energy-storage performance. The blend maintains high discharged energy density (Ue) and charge/discharge (C/D) efficiency at elevated temperatures (shown up to 250 °C), exhibits low conduction loss at high electric fields and temperatures, and survives long-term cycling (demonstrated up to 50,000 cycles at 200 MV/m and 150–200 °C) with preserved film morphology. The work combines experimental dielectric and structural characterisation (SEM, AFM–IR, SAXS, DSC, XRD, broadband dielectric spectroscopy) with theoretical modelling (single- and multi-unit polymer modelling and band-diagram analysis) to explain the enhanced K, bandgap/polarisation optimisation and low-loss behaviour. Data are available in the Article and Supplementary Information; some authors have filed a provisional patent.