Optimizing Energy Storage Density in PVDF-PMMA Bilayer Films through Manipulation of Thickness Ratio

Abstract Energy storage dielectric capacitors have profound significance and significant contributions in the fields of green energy and mechatronics engineering. Studying dielectrics with high energy storage density is of great significance for improving energy utilization efficiency, promoting the development of renewable energy, optimizing power grid operation, enhancing equipment performance, and reducing equipment volume and weight. This study focuses on polyvinylidene fluoride (PVDF) and polymethyl methacrylate (PMMA) double-layer films, examining how their thickness ratio affects energy storage density. The PVDF layer acts as a high dielectric layer, while PMMA serves as an insulating layer. Results show that a higher PVDF thickness ratio leads to greater polarization values but lower electric field strength, while a higher PMMA ratio improves breakdown strength but lowers polarization values. A 1:1 thickness ratio of PVDF to PMMA achieved a discharge energy storage density of 11.4 J/cm 3 at 660 kV/mm with over 80% charge-discharge efficiency. These findings aim to support green energy and mechatronics engineering advancements.