Dielectric Powder/polymer Composites for High Energy Density Capacitors

In this work, we present the synthesis, characterization, and electrical performance of an epoxy/ barium titanate composite. First, the BaTiO3 ceramic powder was examined by X-ray diffraction and scanning electron microscopy and was found to be tetragonal in its crystal structure with a particle size of approximately 1μm and crystals of 57.7nm. It was then established the particles of BaTiO3 could be well dispersed into an epoxy resin matrix using the common ceramic dispersant Menhaden fish oil, in 80/20 ratio by weight xylene to ethanol solvents, via ball milling. Films were synthesized in the geometry specified by ASTM D2149-97, and a dielectric constant of 13 and loss of 0.018 were achieved for composites with a volume filler concentration of 25%. The breakdown strength was 1243 kV/cm at a volume filler concentration of 7 % and decreased as the concentration of BaTiO3 was increased. Energy densities were calculated assuming a linearly behaved composite and were found to be 0.26-0.36 J/cm3 for specimens filled with 7 to 25 % barium titanate