Tricesium
From Star Trek : Freedom's Wiki
Tricesium is a material that can be converted into an energy source.
One of the ships that attacked the USS Voyager upon its entrance into the Void in 2377 had a Warp Core casing composed of tricesium. When Voyager later found the ship crippled and its crew killed, they salvaged the casing and found "Fantome" hiding inside. (VOY: "The Void")
