The 14th Global Conference on Materials Science and Engineering
(CMSE 2025)

Abstract: To address the increasing demand for high-temperature resistance and energy storage performance in modern power electronic devices, this study introduces a novel strategy: modifying polypropylene (PP) films with methyl acrylate trifluoroethyl methacrylate (TFEMA), which contains fluorinated groups, and the polar, electron-deficient molecule 8-hydroxyquinoline (8-HQ). First, kilogram-scale polypropylene grafted with trifluoroethyl methacrylate (PP-g-TFEMA) was successfully prepared. By regulating α-phase crystallization, the films achieved a breakdown strength (Eb) of 865 MV/m and an energy storage density (Ue) of 8.2 J/cm³, with a discharge efficiency (η) exceeding 90%, while retaining excellent processability, self-healing capability, and reliability. Second, 8-HQ molecules were found to capture charges under high electric fields, suppress leakage current, and unexpectedly promote grain growth at the polypropylene interface, thereby enhancing mechanical strength and yielding an Eb of 814 MV/m. In combination with the increased dielectric constant, this enabled a remarkable Ue of 9.87 J/cm³, with η exceeding 90%, and Ue maintained at 6.96 J/cm³ even at 125°C. These findings significantly surpass previously reported results, representing a breakthrough in advancing polypropylene-based dielectric films for high-performance energy storage capacitors.

Keywords: Crystallization, trifluoroethyl methacrylate, 8-Hydroxyquinoline, dielectric energy storage, polypropylene film

Acknowledgements: The authors are grateful for the support and funding from the National Natural Science Foundation of China (Grant No. 92066204, 52373021, 52403074, 52473062), National Key Research and Development Program of China (Grant No. 2023YFB3208400), the Fundamental Research Funds for the Central Universities (No. xzy012024055), Postdoctoral Fellowship Program of CPSF under Grant No. GZC20241337. The author thanked the Instrument Analysis Center of Xi’an Jiaotong University for material characterization.

Biography: Polyvinylidene fluoride (PVDF)-based fluoropolymers are widely used in many fields due to their excellent chemical resistance, heat resistance, aging resistance, weather resistance and solvent resistance. PVDF-based fluoropolymers have high dielectric constants and have been widely used in electromagnetic railguns, electromagnetic catapults, high-resolution sonars, high-sensitivity sensors and other major national needs since their piezoelectricity and subsequent dielectric, ferroelectric, and pyroelectric properties were reported.
The research areas of this team mainly include the design of new fluoropolymers, modification methods, structure-property relationship and regulation of fluoropolymer materials, electroactive fluoropolymers and their applications in high energy storage capacitors, sensors and other fields, as well as the controllable synthesis of novel high-energy-storage polymer dielectric materials, etc.

Our research interests are as follows:
1) Organofluorine Chemistry and Chemical Modification of Fluoropolymers
2) Design and controllable synthesis of advanced energy storage polymers
3) Research on Energy Storage Polymer Composite Dielectric
4) Smart Materials Synthesis and Sensor Applications
5) Biomedical Functional Materials