To improve the performance of LaNi4.1Co0.6 Mn0.3 hydrogen storage alloy, a series of experiments have been performed to study microstructure and electrode properties of LaNi4.1-xCo0.6Mn0.3 Alx(x=0, 0. 15, 0. 3, 0. 45) alloys. XRD analysis indicates that prepared alloys are all single-phase alloys with LaNi5 phase (a hexagonal CaCu5 structure), the crystal parameters (a,c,c/a and V) increase with the increasing of Al content, while the discharge capacity of the alloy electrodes decreases, and the cycling stability, self-discharge properties and discharge ability (323 K) have been obviously improved. The capacity retention after 60 cycles(S60) increases from 58. 79%(x=0) to 79. 72%(x=0. 3) and 79. 35%(x=0. 45), and the self-discharge test shows the irreversible capacity loss (being stored for 96 h) decreases from 14. 41% (x=0) to 2. 38% (x=0. 45). The discharge capacity of alloy electrodes at 323K increases from 266. 04 mA ? h/g(x = 0) to 302. 4 mA ? h/g(x = 0. 15), 302. 12 mA ? h/g(x =0. 3) and 299. 88 mA ? h/g(x=0. 45)respectively. The partial substitution of Al for Ni leads to the decrease of exchange current density(I0) and hydrogen diffusion coefficient(DH) in the bulk electrode, so the poor high-rate discharge ability of these alloy electrodes followed.%为改善LaNi4.1 Co0.6 Mn0.3储氢合金的性能,研究了系列LaNi4.1-xCo0.6Mn0.3Alx(x=0,0.15,0.3,0.45)合金的结构和电化学储氢性能.结果表明:制备的合金为典型CaCu5型AB5储氢合金,随着A1替代量增加,LaNi5相的晶胞参数a、c、c/a值和晶胞体积逐渐增大,相应合金的放电容量有所降低,但合金电极的循环稳定性和不可逆自放电和高温容量得到明显改善.60个循环后的容量保持率(S60)分别为58.79％ (x=0)、79.72％(x=0.3)、79.35％(x=0.45)；合金电极不可逆容量损失率(贮存96 h)由14.41％(x=0)降到2.38％ (x=0.45).在323 K的放电容量由266.04mA·h/g(x=0)增加到302.4mA·h/g(x=0.15)、302.12mA·h/g(x=0.3)和299.88 mA·h/g(x=0.45).但Al替代Ni后,合金电极的交换电流密度I0和氢原子在合金内部的氢扩散系数DH降低,导致其高倍率放电性能变差.
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