Effect of VFe addition on hydrogen storage behavior of TiMn_1.5-based alloys

The hydrogen absorption and desorption behavior of TiMn_1.25Cr_0.25 alloys with Vfe substitution for partial Mn was investigated at 273, 293 and 313 K. It is found that Vfe substitution increases their hydrogen storage capacity, decreases the plateau pressure and the hysteresis factor of their pressure-composition-temperature (PCT) curves. After annealing treatment at 1223 K for 6 h,TiMn_0.95Cr_0.25(Vfe)_0.3 alloy exhibits a lower hydrogen desorption plateau pressure (0.27 Mpa at 313 K) and a smaller hysteresis factor (0.13 at 313 K); the maximum and effective hydrogen storage capacities (mass fraction) are 2.03% and 1.12% respectively, which can satisfy the demand of hydrogen storage tanks for proton exchange membrane fuel cells (PEMFC).