Effect of different metal element substitution on microstructural and comprehensive hydrogen storage performance of Ti0·9Zr0·1Mn0·95Cr0·7V0.2M0.15 (M = Fe, Co, Ni, Cu, Mo) alloy

Hydrogen is now being used as a renewable clean energy carrier. One of the main issues with the application of hydrogen energy is a shortage of security and efficient hydrogen storage technology. TiMn-based alloys are considered promising hydrogen storage materials, but their comprehensive hydrogen storage properties and cyclic stable performance limit their further practical application. The hydrogen storage properties of alloys can be enhanced by substituting transition metal elements. Therefore, the comprehensive hydrogen storage performance of the Ti0·9Zr0·1Mn0·95Cr0·7V0.2M0.15 (M ​= ​Fe, Co, Ni, Cu, Mo) alloys was systematically investigated according to the Mn element on the B side is partially replaced by variety of transition metal elements. The M ​= ​Ni alloy, which showed the highest hydrogen storage capacity among the group of alloys, was used to explore cycle stability. The plateau pressures of the series alloys decreased in order, Fe ​> ​Co ​> ​Ni ​> ​Cu ​> ​Mo. Aspects of hydrogen absorption kinetics, all of the alloys can reach full hydrogen absorption saturation within 400 ​s at 303 ​K. The Ti0·9Zr0·1Mn0·95Cr0·7V0·2Mo0.15 alloy possessed the fastest hydrogen absorption kinetic rate (t0.9 ​= ​65 ​s) and the smallest hysteresis factor. This suggests that the substitution of Mo elements is effective in improving the hysteresis of the Laves phase alloys. Among the series of alloys, the M ​= ​Ni alloy exhibited the best overall hydrogen storage performance, which hydrogen storage capacity can reach 1.81 ​wt% and 97% of its capacity is kept after 100 cycles.