Nanocrystalline materials for hydrogen storage

Hydrogen storage materials research is entered a new and exciting period with the advent of the nanocrystalline alloys. This presentation reviews research at the Poznan University of Technology, on the synthesis and properties of nanocrystalline hydride electrode materials. In our work, nanocrystalline materials have been synthesized by mechanical alloying (MA) followed by annealing. Examples of the materials include TiFe-, ZrV2-, LaNi5- and Mg2Ni-type phases. The properties of hydrogen host materials can be modified substantially by alloying to obtain the desired storage characteristics. The hydrogen storage properties of nanocrystalline ZrV2- and LaNi5-type powders prepared by mechanical alloying and annealing show no big difference with those of melt casting (microcrystalline) alloys. Finally, the electronic properties of nanocrystalline alloys will be presented. The synthesized alloys were used as negative electrode materials for Ni-MH battery.