In high-power electrification sectors, including electric vehicles, renewable energy systems, and aerospace equipment, there are increasingly stringent demands placed on the operating conditions of DC bus capacitors. These capacitors are required to maintain stable operation under high electric fields and elevated temperatures, all while keeping cost and processability in mind. Polypropylene (PP) has traditionally been the dielectric material of choice for capacitors, thanks to its low dielectric loss, high breakdown strength, and well-developed industrial processing system. Nevertheless, the dielectric properties of conventional polypropylene films experience a notable decline when temperatures surpass 105℃. This is characterized by an increase in leakage current and loss factor, as well as a decrease in breakdown strength. The root cause lies in polypropylene's nature as a semi-crystalline polymer, which possesses a substantial free volume in its amorphous regions. Under electric fields, the molecular chain segments in these regions exhibit active motion, readily facilitating charge injection and transport, and ultimately leading to a degradation in dielectric performance. As a result, existing polypropylene capacitors must be operated at reduced capacities in high-temperature environments, which hampers the efficient functioning of electrified equipment.