Until very recently, the main focus when it comes to energy has been on how to generate it. A mix of coal, nuclear power and hydropower - to name only the biggest energy suppliers - can be pretty easily adapted to meet needs. However, all that has changed dramatically in Germany since the decision to abandon nuclear power, move away from coal and promote electromobility - with the end result that energy storage has become crucially important. For decades, there has been little or no progress on mobile energy storage - i.e. batteries - in particular. That makes a recent press release from interdisciplinary research institution Forschungszentrum Jülich all the more encouraging, as it points to a possible renaissance for iron-air batteries.

For reasons including insurmountable technical difficulties, research into metal-air batteries was abandoned in the 1980s. Now, however, interest in this particular research area is really starting to pick up. Working in partnership with Oak Ridge National Laboratory in the US, researchers from Forschungszentrum Jülich have succeeded in observing with nanometer precision how deposits form on the iron electrodes during operation. A solid understanding of charging and discharging reactions is the key to developing this type of battery to the market launch stage. Iron-air batteries are predicted to have theoretical energy densities of more than 1,200 Watt hours per kilogram. By comparison, present-day lithium-ion batteries come in at about 350 Wh/kg if the weight of the cell casing is taken into account. Iron-air batteries are thus particularly interesting for a multitude of mobile applications in which space requirements play a large role.