I'm building a project that involves discharging a fairly large capacitor through a pair of electromagnetic coils. It's electrically very similar to a coilgun, though for a different application. I can't use a supercapacitor because their power density is not high enough, and so I need to find the electrolytic capacitors with the highest energy density, because I'm limited to around 80g for the capacitor.
At approximately what maximum voltage do standard aluminum electrolytic capacitors have the highest energy density? I can design my coil and flyback transformer around the capacitor voltage if there is an advantage to higher voltages, but if they're all approximately the same, I think the electronics would be easier with a 35V cap than a 200V one.
Is there a site or a manufacturer who has a list of capacitors with the energy density for each one? It seems like a feature Parts.io or a similar site would have but I can't find it anywhere. The way I'm doing it now, I have to find the package size for each cap in the datasheet, and then find the weight of that package size and calculate energy density, which is getting rather tedious.
Should I be looking into another capacitor technology instead of electrolytic? I'm having a hard time finding tantalum capacitors this large, and the ones I do find have specs similar to the electrolytics.