Uses of Lanthanum
Lanthanum is used in large quantities in nickel metal hydride (NiMH) rechargeable batteries for hybrid automobiles. The negative electrode (cathode) in NiMH batteries is a mixture of metal hydrides – one of which is typically lanthanum hydride. The active material at the cathode is hydrogen, which is stored in the metal hydride structure. The metal hydride can, depending on its composition, hold between 1% and 7% hydrogen by weight. (3) A Toyota Prius battery requires about 10 kg of lanthanum. (4)