Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : November 02, 2019 - November 04, 2019
It was investigated that the hydrogen absorption-desorption properties of Mg-based compound containing Si, graphite (Gr) that were gotten with ball milling under Ar atmosphere. Milling Si into Mg might decrease the hydrogen desorption temperature of the compound because Si is metalloid and Gr improve the dissolution of hydrogen into the compound at the surface because Gr preventing Mg surface oxidizing. We prepared four kinds of samples, milling of Mg, 5wt.% Si, and 5wt.% Gr against the total weight (Mg-5Si-5Gr), milling of Mg, 10wt.% Si, and 5wt.% Gr (Mg-10Si-5Gr), milling of Mg, 15wt.% Si, and 5wt.% Gr (Mg-15Si-5Gr), milling of Mg, 20wt.% Si, and 5wt.% Gr (Mg-20Si-5Gr). We conducted X-ray diffraction (XRD) analysis, differential scanning calorimetries (DSC), and Pressure-Composition-Temperature (PCT) measurements, scanning electron microscopy (SEM). MgH2 was nucleated in all of the samples after hydrogenation at 280℃ under hydrogen pressure of 0.8 MPa accorrding to the XRD. The DSC profiles showed that all the samples desorbed hydrogen around 395-400℃. Mg-5Si-5Gr, Mg-10Si-5Gr, Mg-15Si-5Gr, and Mg-20Si-5Gr stored hydrogen up to 0.12 wt.%, 1.93 wt.%, 2.52 wt.%, and 1.74 wt.%, respectively at 280℃.
