(1. 天津大學(xué) 化工學(xué)院應(yīng)用化學(xué)系, 天津 300072;
2. 中國科學(xué)院 化工冶金研究所, 北京 100080)
摘 要: 研究了化學(xué)鍍NiCoP鍍層對(duì)貯氫合金電極性能的影響。研究表明, 引入1.74%CoNiCoP合金鍍層可有效地提高負(fù)極貯氫合金活性物質(zhì)的利用率, MH電極的活化性能得到明顯改善,初次放電容量即達(dá)到208 mA·h/g、 最大放電容量達(dá)295.8 mAh/g; 同時(shí)循環(huán)壽命亦有所提高, 化學(xué)鍍NiCoP合金的貯氫電極在進(jìn)行100次循環(huán)充放后,電容量的保持率為88%,而未鍍貯氫電極電容量衰減至62%。 鍍NiCoP合金電極容量的增加,主要是由于Co氧化電流和微電流集流效率改善雙重作用的結(jié)果。 化學(xué)鍍后貯氫合金的抗粉化和抗氧化能力得以改善, 使得MH電極在自放電性能上有較大改進(jìn), 不可逆部分的容量損失由23.2 [KG-*6]mA·h/g降到了3.6 [KG-*6]mA·h/g。 借助于SEM和XRD分析了化學(xué)鍍NiCoP合金對(duì)MH電極性能改善的影響機(jī)理。
關(guān)鍵字: 貯氫合金; 化學(xué)鍍NiCoP合金; MHNi電池
(1. Institute of Chemical Engineering, Tianjin University, Tianjin 300072, P.R.China;
2. Institute of Chemical Metall,Chinese Academy of Sciences, Beijing 100080, P.R.China)
Abstract:The effect of chemical plating with NiCoP 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 NiCoP 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 NiCoP 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.
Key words: Hydrogenstorage alloys; NiCoP coating by electroless plating; MHNi battery


