A rechargeable, aqueous iron air battery with nanostructured electrodes capable of high energy density operation

In order to decrease the global dependence on fossil fuels, high energy density, rechargeable batteries with high charge capacity are required for mobile applications and efficient utilisation of intermittent sources of renewable energy. Metal-air batteries are promising due to their high theoretical energy density. In particular, the iron-air battery, with a maximum specific energy output of 764 W h kg-1Fe, represents a low cost possibility. This paper considers an iron-air battery with nanocomposite electrodes, which achieves an energy density of 453 W h kg-1Fe and a maximum charge capacity of 814 mA h g-1Fe when cycled at a current density of 10 mA cm-2, with a cell voltage of 0.76 V. The cell was manufactured by 3D printing, allowing rapid modifications and improvements to be implemented before an optimised prototype can be manufactured using traditional computer numerical control machining.