Effects of substitution of other elements for nickel in mechanically alloyed Mg50Ni50 amorphous alloys used for nickel—metal hydride batteries
Effects of substitution of other elements for nickel in mechanically alloyed Mg50Ni50 amorphous alloys used for nickel—metal hydride batteries
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DOI：
10.1016/s0925-8388(97)00220-x
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发表时间：
1997-09
影响因子：
6.2
通讯作者：
Wei-hong Liu;Hao-qing Wu;Y. Lei;Qidong Wang;Jing Wu
中科院分区：
文献类型：
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作者：
Wei-hong Liu;Hao-qing Wu;Y. Lei;Qidong Wang;Jing Wu
近年来研究发现，采用机械合金化方法制备的Mg <$Ni非晶合金具有很高的电化学放电容量，但在电化学循环过程中，由于腐蚀的影响，其耐久性很差。本文制备了十余种不同的非晶态合金，其中镍被其他元素部分取代，以改善其电化学性能。结果表明，Ti部分取代Mg 50 Ni 50合金中的Ni，提高了合金的放电容量和降解速率。Zn替代Ni对放电容量没有影响，但会增加劣化速率。Fe、W、Cu、Mn、Cr、Al或C取代Ni可降低材料的劣化速率和放电容量。Se、Sb、Co或Si的取代降低了放电容量和循环寿命。具有较好放电容量和循环寿命的三元合金为Mg 50 Ni 45 M5（M = Mn，Cu或Fe），其最大容量分别为345 mAh·g-1，343.3mAh·g-1和273.3mAh·g-1。9次循环后的容量衰减分别为57.5%、51.4%和40.5%。这远远低于实际使用的要求。
It was recently found that MgNi amorphous alloys prepared by mechanical alloying exhibit a very high electrochemical discharge capacity, but because of corrosion those alloys show very bad durability during electrochemical cycling. In this paper, more than ten different amorphous alloys, in which nickel had been partially replaced by other elements, have been prepared to improve their electrochemical properties. Experimental results show that the partial substitution of Ti for Ni in Mg50Ni50increases both the discharge capacity and degradation rate. The substitution of Zn for Ni shows no effect on the discharge capacity but increases the deterioration rate. The substitution of Fe, W, Cu, Mn, Cr, Al or C for Ni decreases both the deterioration rate and discharge capacity. The substitution of Se, Sb, Co, or Si decreases both the discharge capacity and cycling life. Optimum ternary alloys with reasonable discharge capacities and cycling lives are Mg50Ni45M5(MMn, Cu or Fe), with maximum capacities of 345 mAh·g−1, 343.3 mAh·g−1, and 273.3 mAh·g−1respectively. The capacity degradation after 9 cycles is 57.5%, 51.4% and 40.5% respectively. This is far below the requirement for practical usage.