thecarchik writes "Most advocates and industry analysts expect lithium-ion batteries to dominate electric-car energy storage for the rest of this decade. But is Tesla Motors planning to add a new type of battery to increase the range of its electric cars? Tesla has filed for eight separate patents on uses of metal-air battery technology (for example, #20120041625). The metals covered for use in the metal-air battery are aluminum, iron, lithium, magnesium, vanadium, and zinc. Metal-air batteries, which slowly consume their anodes to give off energy, hit the news last month when Israeli startup Phinergy demonstrated its prototype battery and let reporters drive a test vehicle fitted with the energy-storage device. Mounted in a subcompact demonstration car, Phinergy's aluminum-air battery provides 1,000 miles of range, it said, and requires refills of distilled water (which acts as electrolyte in the cells) about every 200 miles."