At elevated temperatures the lattice becomes an ionic conductor, with the major contribution to charge transport from positive ion vacancy motion.

They change into ions with a two positive charge ... Ionic compounds form what is known as a lattice structure. This is a regular arrangement of metal and non-metal ions which creates compounds ...

joins with a positive ion (an atom that has lost an electron). form a regular lattice structure in which oppositely charged ions are strongly attracted to each other. Sodium chloride is an ionic ...