The Electrium Z (Japanese: デンキZElectric Z) is a type of Z-Crystal introduced in Pokémon Sun and Moon. It is the type-specific Z-Crystal associated with the Electric type and allows Pokémon to upgrade their Electric-type moves to Z-Moves.
Unaffected by item negating effects (such as Embargo and Klutz). Item manipulating effects (such as Trick and Fling) cannot remove a Z-Crystal from a Pokémon.
In Trial and Tribulation!, Ash obtained another Electrium Z from Tapu Koko. It had swapped it with the Fightinium Z that he was supposed to receive from Hala as a reward for completing his Melemelegrand trial. In 10,000,000 Reasons to Fight!, this specific Electrium Z was revealed to have the unique ability to temporarily transform into a Pikashunium Z. This transformation reoccurred in A Battle Hand-Off! and SM144, with the latter transformation actually being permanent. The reason and cause for these transformations have not been explained.
Dia was revealed to have an Electrium Z in Parallel Friendships!. He uses it to perform Gigavolt Havoc with his partner, Zeraora.
A full set of type-specific Z-Crystals, including the Electrium Z, appeared in A Grand Debut!, where Hapu allowed Ash to choose his grand trial prize from them.
A full set of replicas of the type-specific Z-Crystals, including the Electrium Z, appeared in A Team-on-Team Tussle!, where they were shown to Ash and his classmates by Professor Kukui.