化学镀Ni-Co-P合金对贮氢电极电化学性能的影响
来源期刊：中国有色金属学报2000年第5期
论文作者：唐致远 孙春文 郭鹤桐
文章页码：757 - 762
关键词：贮氢合金； 化学镀Ni-Co-P合金； MH-Ni电池
Key words：Hydrogen-storage alloys； Ni-Co-P coating by electroless plating； MH-Ni battery
摘 要：研究了化学镀Ni-Co-P镀层对贮氢合金电极性能的影响。研究表明， 引入1.74%CoNi-Co-P合金镀层可有效地提高负极贮氢合金活性物质的利用率， MH电极的活化性能得到明显改善，初次放电容量即达到208 mA·h/g、 最大放电容量达295.8 mAh/g； 同时循环寿命亦有所提高， 化学镀Ni-Co-P合金的贮氢电极在进行100次循环充放后，电容量的保持率为88%，而未镀贮氢电极电容量衰减至62%。 镀Ni-Co-P合金电极容量的增加，主要是由于Co氧化电流和微电流集流效率改善双重作用的结果。 化学镀后贮氢合金的抗粉化和抗氧化能力得以改善， 使得MH电极在自放电性能上有较大改进, 不可逆部分的容量损失由23.2mA·h/g降到了3.6mA·h/g。 借助于SEM和XRD分析了化学镀Ni-Co-P合金对MH电极性能改善的影响机理。
Abstract: The effect of chemical plating with Ni-Co-P alloy of hydrogen storage alloy on the properties of MH electrodes was investigated. The results show thatthe efficiency of activation material of hydrogen storage alloy has been improved by introducing 1.74 percent cobalt in the Ni-Co-P alloy coating. The initial discharge capacity is 208 mA·h/g. The maximum discharge capacity gets to 298.5 mA·h/g. At the same time the cycle life of MH electrodes is improved. The dischargecapacity of MH electrodes coated with Ni-Co-P is 88 percent of the maximum discharge capacity after 100 cycles. Whereas the discharge capacity of bare alloy electrodes retains 62 percent of the maximum capacity after 100 cycles. An increment of discharge capacity is mainly due to superposition of the oxidation currentof Co as well as improved efficiency of microcurrent collection. The ability toanticrushing and antioxidation is also improved so that the rate of selfdischarge of MH electrodes is reduced, particularly the irreversible part of capacity loss reduced from 23.2 mA·h/g to 3.6 mA·h/g. The affecting mechanism is analyzed with the help of SEM and XRD analyses.
