The rapid expansion of renewable energy, electrified transportation and advanced electromagnetic power systems requires electronic devices that can operate stably at harsh temperatures (e.g., 150 to 250 °C). However, as one of the critical components of electronic devices and power systems, film capacitors can currently only operate at temperatures below 105 °C because conventional polymer dielectric materials suffer from high conduction loss at high temperature and high electric field, resulting in severe heat accumulation and thermal runaway of film capacitors.