Electro-cell

Was not found yesterday.

An electro-cell is a powerful energy source devised by Human scientists. The Decepticon Megatron and his forces broke into the facility where the electro-cells were being held and steals them, planning to use them for the usual purpose (i.e. conquest). Megatron's plans were thwarted by the Autobot Mirage, in a ploy that involved his teammates briefly thinking him a traitor.

It is stated that if the electro-cells were to overload, they could start a chain reaction that very well could destroy the entire planet Earth. Exactly how this would work is unclear.

From Teletraan I: The Transformers Wiki, a Wikia wiki.