This research aimed to investigate the problems arising in the energy storage unit for iron air batteries. In particular, the coefficients of expansion and contraction at different temperatures observed when using iron foam materials in the energy storage unit when reduced with hydrogen gas. Reduction reactions conducted at temperatures ranging from 700 to 1000◦C under hydrogen and forming gas. The expansion and contraction process, which is one of the main problems encountered in the reduction of iron oxide with hydrogen and its use as an energy storage unit, has investigated. Microstructure and porosity of iron foam material used as energy storage unit analyzed. In this study, we examined the porosity structures formed during the reduction of iron oxides using two different reducing gases. The formation of microstructure and porosity and their amount calculated using computer programs.

hydrogen reduction of iron oxides; iron oxides; swelling index; porosity, energy storage unit

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