Phase structure and hydrogen sorption performance of Ti-Mn-based alloys

The phase structures and hydrogen absorption-desorption properties of TiMn1.25-xCr0.25Vx (x=0, 0.2, 0.3, 0.4 and 0.5) alloys were investigated in order to develop a suitable material for hydrogen storage tank for proton exchange membrane fuel cell (PEMFC) applications. It was found that the increasing V content is effective for improving the activation performance, enhancing the hydrogen absorption capacity and decreasing the hydrogen desorption plateau pressure. The best composition among the studied alloys is TiMn0.95Cr0.25V0.3 alloy, which has a suitable plateau pressure (0.43 MPa) and a small slope and a small hysteresis. Its maximum and effective hydrogen storage capacities are about 2.2 and 1.7 wt.% at 293 K, which is higher than for any other reported Ti-Mn-based alloys thus far