In Star Trek technobabble
dilithium crystals are the thingies that energy
is channeled through in order to get it from the matter
reaction chamber to the warp engines
. They can also store some of the energy and be used like a battery
. They're kinda like the spark plug
of a starship
and if they melt, which they often do, the ship ain't goin' nowherez.
Now what's dilithium? Well first off, what's lithium? Well, among other things, lithium hydride batteries are used to power some portable computers and other electronic equipment. So dilithium is just REAL KEWL lithium! Don't snort it though. Makes your nose bleed.