Acrylic Plastic Polycarbonate 1/4" X 4" Round Sheet Reviews

“For the ends of some prototype high voltage electric-double-layer-capacitors. I know a couple people following me on here seem to know chemistry, so as an aside - anyone know an easy way to synthesize ammonium-bisimide? I ask because I really don't want to get near ammonium-cyanimide but have heard good things about room-temp molten ammonium-imide's as high energy density electrolytes.”