羟基镍粉对AB_5型储氢合金电化学性能的影响

本文采用真空感应电弧炉熔炼制备了AB5型储氢合金,经机械研磨后与Ni粉充分混合,通过三电极体系测定了储氢合金电极Mm0.3Ml0.7Ni3.55Co0.75Mn0.4Al0.3/Ni的电化学性能。试验结果表明,羟基镍粉的添加极大的提高了储氢合金的电化学性能。与未添加Ni粉的合金电极相比,所有Mm0.3Ml0.7Ni3.55Co0.75Mn0.4Al0.3+Xωt%Ni(x=0～300)电极经2次充放电循环后均完全活化,且其最大放电容量随着羟基镍粉含量的增加而增大。此外,在大电流放电试验中,添加Ni粉的合金电极显现出良好的高倍率放电性能。其中,当x=200时,合金电极仅经过1次充放电循环即可活化;其最大放电容量可达314mAh/g;高倍率放电能力HRD300为81.2%。

Impact of Hydroxy Ni Powders on Electrochemical Properties of AB5 Hydrogen Storage Alloy

The Mm0.3Ml0.7Ni3.55Co0.75Mn0.4Al0.3/Ni were mechanically synthesized and electrochemically tested in three-electrode system.The results show that the electrochemical properties of the electrodes mixed with Ni powder were greatly improved.The electrodes of Mm0.3Ml0.7Ni3.55Co0.75Mn0.4Al0.3/Ni were all activated after the second charge-discharge cycle,and the maximum discharge capacity increased with the increase of Ni content.In addition to that,adding Ni powder improved the high-rate discharge property.The electrode of Mm0.3Ml0.7Ni3.55Co0.75Mn0.4Al0.3+200ωt% Ni exhibited good properties in general:its activation number,the maximum discharge capacity,HRD300 were 1,314mAh/g,81.2% respectively.