Production of hydrogen storage alloy of Mg₂NiH₄ by hydriding combustion synthesis in laboratory scale

A laboratory scale production method for hydrogen storage alloy of Mg₂NiH₄ by hydriding combustion synthesis was investigated. In this study, cylinders of magnesium and nickel mixture powder, compressed at different pressures, and a powder mixture of metals, without the compressive treatment, were used as a raw material. The products were examined by X-ray diffraction (XRD) and scanning-electron microscopy (SEM). The XRD results indicated that pure Mg₂NiH₄ was simply obtained not only from the compressed cylinders, but also from the powder. There was no significant effect of the compressive pressure of the cylinder on the composition of the final products. However, SEM observations showed that the compressed sample and the powder are clearly different, in spite of the same product composition. The results also revealed a possibility of new production system of Mg₂NiH₄ using hydriding combustion synthesis, with many benefits of simple pretreatment, including: simple equipment, short operating time, high-quality product, and energy savings.