201 / 2022-03-14 17:46:37

Poly(ether imide) Sandwiched by Ultrathin Hafnium Oxide films for High-temperature Capacitive Applications

polymer dielectrics,capacitors,high temperature,electrical energy storage,hafnium oxide

Polymer film capacitors are essential energy storage components in advanced electrical and electronic systems. Recently, many industrials require capacitors operating at the temperature as high as 200 ℃, while polymer dielectric materials suffer from significantly increased conduction loss under elevated temperatures. To address this issue, we deposited ultrathin wide-bandgap HfO₂ films onto both sides of Poly(ether imide) (PEI) substrate using atomic layer deposition (ALD) and investigated the leakage current, breakdown strength and energy storage performance of HfO₂/PEI/HfO₂ composites at 200 °C. Experiment results show that a dense and uniform layer of amorphous HfO₂ forms on the surface of PEI. The resultant composites exhibit reduced leakage current, enhanced breakdown strength, enhanced charge-discharge efficiency and discharged energy density compared with neat PEI. Moreover, thicker HfO₂ coating layers are more effective in suppressing the conduction loss at elevated temperatures.