Aluminum-Anodes for Metal-Air-Batteries

Aluminum-Air-Batteries are a promising alternative to Lithium-Ion-Batteries. The theoretical specific energy density of aluminum at 8100 Wh/kg passes over 600 Wh/kg of Lithium-Ion-Batteries, significantly. Aluminum offers the second-highest metal deposit in the Earth’s crust. A low density of 2,7 g/cm³ offers further potential for weight reduction. The major challenges with Aluminum-Air-Batteries are the unwanted development of a passivating oxide layer on the anode’s surface and the “Parasitic Corrosion”, a hydrogen evolution caused by free electrons released by corrosion. Research works have shown that a reduction of an anode’s grain size will achieve a higher energy density and a lower hydrogen evolution. In addition, a 3-D-surface-structured anode provides a bigger active surface, and therefore a higher performance. Extrusion was chosen as a well-known process meeting the potential of a production at industrial scale. Al-Anodes manufactured from cast (Al 99.8%, extruded (Al 99.8%), and foam (Al 99.5%) were compared in corrosion- and battery-performance-tests.