Storing energy in metals

A German institute and a Dutch university are investigating how iron can be used to store energy.

The possibility of storing excess energy in iron and releasing it through combustion of iron into iron oxide is being investigated by the Max Planck Institute for Iron Research in Germany and the Eindhoven University of Technology, Netherlands.

According to the researchers, the process of storing energy in metals and burning them is already used in aerospace technology.

The idea is to get the energy out of iron ore reduced to iron. The team focused on the characterisation of the iron powders after reduction and combustion, using advanced microscopy and simulation methods to analyse the powder purity, morphology, porosity, and thermodynamics of combustion.

The obtained microstructure of the combusted iron powders is decisive for the efficiency of the following reduction process.

The scientists used two combustion pathways, one with a propane pilot flame and one self-sustained in which the only fuel used is iron powder.

They say they are upscaling the reduction and combustion steps to an industrially relevant level to finesse the required parameters, e.g. temperature.