D. Langhe, M. Ponting
PolymerPlus LLC, United States
pp. 5 - 8
Keywords: multilayered films, capacitors, pulsed power, energy storage
Current state-of-the-art polymer film capacitors have a limited energy density of 2.4 J/cc for pulsed power and energy storage applications, and are based on twenty year old technology and materials. Improving the energy density limit of polymer capacitors can enable compact and more efficient systems. In pulsed power applications, performance of existing biaxially oriented polypropylene (BOPP) based capacitors for energy storage is limited when operated above 2 J/cc and occupy large volume. The potential advantage of PolymerPlus translated multilayered film technology includes increased energy density capability, high temperature stability while maintaining low losses and significant size reduction over existing BOPP capacitors. Multilayering a high dielectric constant polymer (polyvinylidine fluoride, PVDF or its copolymers) with a high dielectric breakdown polymer (polycarbonate, PC) has produced high energy density and low loss dielectric films. It was demonstrated that the dipole flipping in PVDF was significantly restricted in the multilayered structure thereby reducing the losses. By optimizing the layer thickness, number of layers, and the composition; multilayered films developed by PolymerPlus were used to fabricate 0.5 µF capacitor prototypes. The first attempt demonstrated successful fabrication of the capacitors with temperature rating of 160 °C.