Electricity requires the movement of electrical charges.
We normally think of moving electrons , but it is not necessary that the charges be electrons as long as they can move. Ions cannot move in the crystal any more than an orange, one of several tightly stacked in a crate, could freely move through the stack from one side of the crate to another. But suppose you tear open the crate and pour out the oranges. Now the oranges can move freely. All rights reserved.