【摘要】 研究了熔体旋淬和常规熔铸Ml(NiCoMnAl) 5贮氢合金的微结构和电化学行为。SEM和XRD分析表明 ,熔体旋淬合金由细小的柱状晶组成 ,它们的晶体结构与铸态一样 ,都为CaCu5型六方晶体结构。电化学测试表明 ,旋淬态合金电极初始容量较高 (>2 10mA·h/ g) ,经 1～ 2次循环就可达到最大放电容量。旋淬速度为 10m/s的合金电极的放电容量 (2 94mA·h/g)稍高于铸态合金电极的容量 ,所有旋淬态合金电极充放电循环稳定性皆优于铸态合金。在 6 0 0mA/ g电流质量密度下 ,旋淬速度为 10m/s的合金电极具有较好的高倍率充放电能力 ,但随着循环次数的增加 ,其容量稳定性稍次于旋淬速度为 2 5m/s和 40m/s的合金电极。更多还原

【Abstract】 The microstructure and electrochemical behaviors of Ml(NiCoMnAl) 5 alloys prepared by both the melt spinning method and the conventional induction melting were investigated. SEM and XRD analysis show that melt spinning alloys are of columnar microstructure which belong to the CaCu 5 type hexagonal crystal structure as same as as cast alloy. The electrochemical measurements show that the initial capacities of melt spinning alloy electrodes are all above 210 mA·h/g, reaching their maximum capacities after the second charge discharge cycles. The maximum capacity (294?mA·h/g) of melt spinning (10?m/s) alloy electrodes is the same as that of as cast alloy electrode, the stability of charge discharge cycles of all melt spinning alloy electrodes is better than that of the as cast alloy electrodes. When charged at 600?mA/g, the melt spinning (10?m/s) alloy electrode has better high rate discharge capability; but with the cycle number increasing, the cycle stability is less than those electrodes of melt spinning rate of 25?m/s and 40?m/s. [更多还原