High Energy Density and Discharging Efficiency Achieved in Chlorinated Polyethylene Films for High Energy-Storage Applications

Polymeric dielectric materials with high energy density (U_e), elevated breakdown strength (E_b), and high discharging efficiency (η) are in demand for high-pulse metalized film capacitor application. In the present work, a randomly chlorinated polyethylene (CPE) with 71 wt% Cl moiety is fabricated in thin film (8–10 µm). Thanks to the high Cl content, CPE exhibits a rather high glass transition temperature (≈110 °C) and a Young's modulus of 2.6 GPa, which may address its high E_b. The random dispersion of Cl atoms onto the polymer chain is responsible for the well-maintained medium permittivity (3–4) and low loss at elevated temperature. Both factors result in the rather high U_e (about 12 J cm⁻³) and high η (about 83%) under an electric field of 700 MV m⁻¹. Its higher energy-storage capability and operating temperature make CPE a promising polymeric dielectric for high-pulse metalized film capacitor applications.