An Investigation On The Structural And Electrochemical Properties Of La_15-x Nd_x Fe₁₄ Ni₆₄ Mn₅ B₂ (x=0-6) Hydrogen Storage Alloys

La-Fe-B system hydrogen storage alloys with an good electrochemical performance like LaNi5 type alloys are a new type of rare earth function material, which adopts Fe,. Compared with LaNi5, La-Fe-B system hydrogen storage alloys have a cost lower 10-40% due to the Co-free. Various hydrogen storage electrode materials could be developed to meet different demands. With a promising market and remarkably economical and social anticipation, this new type of La-Fe-B hydrogen storage electrode material deserves deeper research.Element substitution is a one of the methods for further research aiming to ameliorate hydrogen storage material's electrochemical performance. In this paper, La₁₅Fe₁₄Ni₆₄Mn₅B₂ is substituted its La by Nd so as to observe element Nd's effect on the alloy's phase structure and electrochemical performance.Hydrogen storage alloys La_15-xNd_xFe₁₄Ni₆₄Mn₅B₂(x=0,2,4,6) were prepared by medium frenquency induction melting and quick-quenching. The alloys were tested by X-ray diffraction to identify their phases. There is no new phase although La is partly replaced by Nd except for slightly movement of diffraction peaks to high angle direction. Alloys'Surfaces are also observed by SEM and compositions are determined by EDS. Results show there are three phases in alloys: LaNi₅, (Fe,Ni) and La3Ni13B2. La_15-xNd_xFe₁₄Ni₆₄Mn₅B₂(x=0,2,4,6) alloys electrodes were tested for eletrochemical performances. The highest capacity appears when x equals 2, then maximum capacity declines with increasing x. Small amount of Nd substitution for La could broaden plateau of discharge curve and improve electrode's P-C-T curve plateau. Nd substitution for La also provides some improvement for electrode's cycle performance. Alloy has a better HRD performance when x=2, but it declines as x increases. Generally speaking, small amount of Nd substitution for La has a positive effect on properties of La₁₅Fe₁₄Ni₆₄Mn₅B₂ alloy electrode.Anealing reduces numbers of activating, increases highest capacity, distinct enhances high rate discharge ability. But anealing also causes adverse effect on cycling performance.