Manipulating epoxy-polycarbonate sandwich films with enhanced dielectric performance via solution-immersion process

• Published in: Materials letters 2024-09, Vol.371, p.136947, Article 136947
• Main Authors: Chen, Yingxin, Luo, Jiaming, Li, Mingsheng, Yi, Shiyang, Cheng, Yonghong, Zhang, Lei
• Format: Article
• Language: English
• Subjects: Breakdown strength; Dielectrics; Energy storage and conversion; Sandwich structure; Solution-immersion
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2024.136947

•A solution-immersion method was developed to fabricate sandwich polymer films.•A high breakdown strength of 709.4 MV/m is achieved by sandwich structure.•The epoxy-polycarbonate sandwich film has an ideal energy density of 8.44 J/cm3.•Sandwich structure retains high dielectric constant with low dielectric loss.•The discharge energy density reaches 1 J/cm3 at 200 MV/m, 100 % better than BOPP. Epoxy-polycarbonate sandwiched films with enhanced dielectric performance were prepared in this study. Unlike traditional tedious multiple scratch-coating approach, the sandwich dielectric films were prepared based on a convenient solution-immersion process. Polycarbonate solutions with different concentration were applied to adjust the film composition and compared with epoxy-polycarbonate blending film. We found that rather than deteriorating the breakdown strength as shown in the blending counterpart, sandwiched films prepared by solution immersion shows superior breakdown strength (709.6 MV/m), almost 40 % better than both epoxy and polycarbonate components. Moreover, tan δ of the films prepared from solution-immersion (