Relaxor Terpolymer-Ceramic Composites for High Dielectric Constant, Energy Storage Capacitors

In this proposed effort TRS Technologies will demonstrate the feasibility of using relaxor ferroelectric polymer-ceramic composites for energy storage capacitors. Pulsed power systems such as electromagnetic and electrothermal guns, directed energy weapons, electromagnetic armor, and megawatt-level uninterruptible power supplies require high energy density, fast discharge speed (<1 to 10 us) capacitors that cannot be fabricated with commercially available dielectrics. Recently developed relaxor-ferroelectric terpolymer (PVDF-TrFE-CTFE) exhibits a dielectric constant > 60; 20 to 30 times the values of existing polymer film capacitors. This is a dramatic breakthrough in itself, but even higher dielectric constants have been achieved by fabricating relaxor-relaxor composites from relaxor polymer and PMN-PT ceramic powder. The composites have the advantage of combining the high breakdown strength of polymer materials with the high dielectric constant of the ceramic. A high dielectric constant combined with high breakdown strength is expected to result in energy densities greater than 15 J/cm3. For this Phase I program TRS and Prof. Qiming Zhang from Penn State will fabricate terpolymer-ceramic composites and measure their dielectric properties and energy density. In Phase II we will develop a variety of high energy density capacitors from this material.