二元稀土系AB_5型贮氢电极合金的放电容量与晶胞体积和4f电子浓度的关系

RELATIONSHIPS OF DISCHARGE CAPACITY OF AB_5-TYPED HYDROGEN STORAGE ELECTRODE ALLOYS WITH CELL VOLUME AND SPECIFIC 4f ELECTRONIC CONCENTRATION

制备了6个系列通式为A_αA_(1-α)B_5的RE(NiCoMnTi)_5贮氢电极合金(其中,A_αA_(1-α)为La,Ce,Pr,Nd 4个元素中任意2个的组合),测定了它们在100次循环中的最大放电容量C_(max)及部分合金的晶胞体积V_(cell),结果表明:C_(max)主要由V_(cell)决定,C_(max)先随V_(cell)的增大而增加,在V_(cell)≈85.66×10^(-3)nm^3时达到一极大值,然后又随V_(cell)的增大而减小;同时,C_(max)还与4f电子浓度n_(e_(4f))/n_(a_(RE))有关,A侧具有相同4f电子浓度的合金其C_(max)随4f电子浓度的变化趋势相似。

Six series of hydrogen storage electrode alloy RE (NiCoMnTi)(5) with a general formula of AalphaA'B-1-alpha(5) were prepared where A(alpha)A'(1-alpha), is binary rare earth metal mixture among La, Ce, Pr, Nd, and B is nickel partially substituted by Co, Mn and Ti. The samples obtained were then charged and discharged for 100 cycles to determine their maximum discharge capacity C-max, and cell volumes V-cell of some alloys were measured. It is found that C-max is mainly changed with Kell, but the variation tendency is affected by specific 4f electronic concentration ne(4f) / na(RE). With V-cell increasing, C-max increases to a maximum value first and then decreases. The alloys with the same ne(4f) / na(RE) shows similar C-max variation in their series.