Aluminum-Air Battery

An aluminum-air battery produces electricity from the reaction of oxygen in the surrounding air with an aluminum anode, and the chemistry gives it one of the highest energy densities of any battery type, though the high cost of the aluminum anode and the difficulty of removing the reaction byproduct have restricted its practical use mostly to military applications. Aluminum-air cells are primary cells, meaning they are not rechargeable in the ordinary sense; once the aluminum anode has fully reacted with atmospheric oxygen at a water-based electrolyte cathode to form hydrated aluminum oxide, the battery stops producing electricity, though it can be mechanically recharged by replacing the spent anode with a new one, and that anode material can in turn be recycled back into new aluminum. The technology appeal for electric vehicles lies in its potential range, with hybridized aluminum-air and lead-acid road tests reported as early as 1989 and an aluminum-powered plug-in hybrid minivan demonstrated in Ontario in 1990; more recently, in 2013 the company Phinergy demonstrated an electric car powered by aluminum-air cells that was driven 330 kilometers on a single set of anodes, and Israeli media later reported an aluminum-air-equipped car claiming a range of up to 2,000 kilometers before the anodes needed replacement.