Improving the Energy Density and Efficiency of the Linear Polymer PMMA with a Double-Bond Fluoropolymer at Elevated Temperatures

A variety of applications can be found for high-temperature film capacitors, including energy storage components and pulsed power sources. In this work, in order to increase the energy density (U_e), poly(vinylidene fluoride-chlorotrifluoroethylene-double bond) (P-DB) is introduced into poly(methyl methacrylate) (PMMA) to manufacture composite films by a solution casting process. In the case of the pure PMMA film, there is significant improvement in the polarization (P_max) and breakdown field (E_b) of the composite film. These improvements can effectively increase the U_e of the composite film at room temperature and the elevated temperature. The results show that at an elevated temperature of 90 °C and at 350 MV/m, the U_e of 40 vol % P-DB reaches 8.7 J/cm³, and the efficiency (η) of 77% is also considerable. Compared with biaxially oriented polypropylene (2.0 J/cm³), the proposed film exhibits 4 times enhancement in the energy storage density, meaning that it can be an energy storage capacitor with huge potential at high temperatures.