Improvement of high-temperature energy storage performance of PC/FPE all-organic composite dielectrics based on functional multilayer structure design

Polymer dielectrics, as a crucial role in electrostatic capacitors used in transport, oil exploration, the manufacturing industry, avionics domain, reach operating temperatures of 120 °C or more. However, the significant reduction in the capacity of energy storage at high temperatures greatly restricts polymer dielectrics used in such environments. By adjusting the distribution of functional layers, has designed all-organic multilayer composite dielectrics that can significantly inhibit carrier conduction at high temperatures, thereby enhancing the energy storage density. Among them, highly insulating polycarbonate (PC) is the outer layer, and highly heat-resistant fluorene polyester (FPE) forms the inner layer. The various distribution ratios that impacted the performance of these composite dielectrics have been thoroughly investigated. The research finds that the five-layer structured composite dielectric with PC and FPE layers composite dielectrics (PFPFP) have superior temperature stability and energy storage capabilities. In particular, they are able to withstand up to 350 kV/mm electric field strength ( E b ) at 150 °C, and the energy storage density of 2.15 J/cm 2 and the efficiency of 90.1 % is 3.98 times that of pure PC. It is suggested that the method of using the merits of different function layers to increase the dielectric energy density is suitable for different polymer films under severe conditions.