Hydrogen Absorption and Evolution Capabilities of Porous Ti-15V-3Al-3Cr-3Sn Electrodes from Hot-Press Sintering

Ti-15V-3Al-3Cr-3Sn alloy (Ti-153) plates were subjected to a hydriding process to obtain Ti-153 powder which was further hot-press sintered (HPS) into porous electrodes to see their hydrogen storage and evolution capabilities. The effects of processing parameters on the hydrogenation behavior were characterized qualitatively and quantitatively utilizing X-ray diffractometry (XRD: D2 PHASER, BRUKER, USA, 30 kV-10 mA, Cu-Kα λ = 1.541838 Å), scanning electron microscopy (SEM: Hitachi 4800), and elemental analysis (EA: Heraeus vario III-NCSH). XRD and EA analyses demonstrate that the hydrogen absorption and evolution capabilities of the powdered electrodes are superior to those of the original bulk sheet specimens. The hydrogen uptake of the specimens was evaluated by cyclic electrolytic hydrogenation at 50 mA/cm2 for various periods in a 1N H2SO4 aqueous solution containing 0.1 g/L As2O3, followed by solution treatment in a muffle furnace at 300 °C for 1 h. The subsequent dehydrogenation process was conducted at 300 °C and 4.67 Pa for 2 h. The optimal processing conditions in this study are as follows: (1) first, the Ti-153 sheets are treated in a hydrogen furnace at 300 °C under a hydrogen pressure of 50 atm for 15 h to obtain the raw powder; (2) subsequently, the raw powder is processed in a hot-pressing sintering furnace at 600 °C under 25 MPa for 2 h to yield the sintered electrodes.