包钴球型Ni(OH)_2在充放电过程中的结构变化  

Structural changes of spherical Ni(OH) 2 coated by cobalt during charge/discharge

作　　者：阎杰[1] 周震[1] 王先友[1] 王登国 

机构地区：[1]南开大学新能源材料化学研究所,天津300071

出　　处：《电源技术》2000年第1期28-31,共4页Chinese Journal of Power Sources

摘　　要：通过化学镀的方法在碱性可充电电池正极活性物质———球形Ni(OH)2表面包覆了金属钴。通过恒电流充放电实验发现,球型Ni(OH)2表面包钴后,可明显提高活性物质的利用率,增加电极反应的可逆性。用XRD法比较研究了包钴和掺钴球型Ni(OH)2正极在充放电过程中相的生成和变化。结果表明:在充电过程中,掺钴的球型Ni(OH)2极易生成γNiOOH,而包钴的球型Ni(OH)2可抑制γNiOOH的生成;在放电至正极电位为0.1V(vs.HgO/Hg电极)时,掺钴的球型Ni(OH)2还明显存在γNiOOH,而包钴的球型Ni(OH)2只存在少量γNiOOH。这说明在球形Ni(OH)2颗粒表面包覆钴镀层后,其导电性能得到提高,从而更有利于充放电反应的进行,而γNiOOH得到抑制对于提高Ni(OH)Spherical Ni(OH) 2 was coated by cobalt through the electroless plating method. The treated active material exhibits better utilization and more reversibility than spherical Ni(OH) 2 mixed with cobalt as conductor according to the constant current charge/discharge test. Studies were focused upon the structural changes during charge/discharge process of the two samples by XRD method. Experimental results exhibit that spherical Ni(OH) 2 mixed with cobalt tends to form γ NiOOH. However, spherical Ni(OH) 2 coated by cobalt can prevent the formation of γ NiOOH. After discharging to 0.1 V vs. HgO/Hg reference electrode, less γ NiOOH remains in the coated sample than the mixed sample. All results show that the electrical conductivity of spherical Ni(OH) 2 is improved by cobalt coating and the charge/discharge reaction is easier to carry out. Moreover, the prevention of γ NiOOH is beneficial to the cyclic life of Ni(OH) 2 electrodes.

关 键 词：氢氧化镍 化学镀钴 结构 MH-NI电池 充电 放电 

分 类 号：TM912.206[电气工程—电力电子与电力传动]