I tried to get some of the EnderIO capacitors using the Loonium but none of EnderIO's loots are dropping from it.
Here is what's dropping from it:

Minecraft: 1.10.2
Mods: list.txt

it just uses the dungeon loot table, so check if they're showing up in dungeon loot (set the loot table on a chest using /blockdata and open it). I have no idea otherwise

^ and closing from staleness