Investigation of La-Y-Ni based alloys with various Y content on gas–solid hydrogen storage performance

Abstract

La-Y-Ni-based hydrogen storage alloys demonstrate tremendous application potential due to the superiority of hydrogen storage performance and manufacturing process. However, the insufficient research of La-Y-Ni-based hydrogen storage alloys in solid state hydrogen storage field compared with electrochemistry field limit their further development, especially for the effect of Y element in the alloys. Herein, in this work, a series of La-Y-Ni-based hydrogen storage alloys with various Y content were synthesized, and the structure/solid state hydrogen storage performance variation as well as structural stability, kinetics and thermodynamic properties of the alloys were explored systematically. The results exhibit La_0.25Ce_0.25Y_5.5Ni₂₂Mn_0.8 alloy display the superior synthetic performance with a maximum hydrogen adsorption capacity of 1.54 wt% within 150 s and the dehydrogenation platform pressures of 0.40/1.80 MPa, and even better, a capacity retention ratio above 99 % after 100 cycles can be reached. Kinetic mechanism research reveals that the gas–solid reactions between hydrogen and La_0.25Ce_0.25Y_5.5Ni₂₂Mn_0.8 alloy are controlled by branching nucleation, and the calculated thermodynamic parameters of alloys are well consistent with hydrogen storage properties.