Desorption behaviour of MgH2-Ni-SiC prepared by ball milling for hydrogen storage material application

Magnesium (Mg) is one potential candidate that can be used as a hydrogen absorbent. Theoretically, Mg can absorb large amounts of hydrogen up to 7.6 wt.%. However, the kinetic reaction of Mg in absorbing hydrogen takes at least 60 minutes when it occurs at high temperatures (300-400 degrees C). The purpose of this study is to increase hydrogen desorption capacity and the working temperature of the MgH 2 -Ni-SiC-based storage system. The materials preparation was done with mechanical alloying technique. The milling process was varied for three different times of 5 h, 10 h and 15 h, with the two catalyst ratios of five wt.% and ten wt.% and the speed of 350 rpm. X-Ray Diffraction (XRD) measurement results revealed that the sample has successfully become nano-sized crystals with the dominant phase of MgH2 and the minor phases of Ni and SiC. The irregular shape of the particles and their non-homogeneous size are known form the Scanning Electron Microscopy (SEM) results, which are caused by agglomeration. The best hydrogen desorption capacity of up to 2.6 % and the lowest temperature desorption of was 365 degrees C was obtained for samples that were milled for 10 hours with five wt.% Ni-SiC catalyst.