( 1. 北京化工大学 化学工程学院, 北京 100029;
2. 北京化工大学 理学院, 北京 100029)
摘 要: 用高浓度KClO-KOH混合液在常温下一步氧化掺钴球形氢氧化镍, 通过洗涤和真空干燥得到高纯度羟基氧化镍。 利用扫描电镜、 X射线衍射和激光粒度仪等对样品的结构进行了表征, 结果表明: 样品为具有球形形貌、 粒径在220.1~650.9 nm之间的超细羟基氧化镍晶体。 通过恒流放电实验研究了3种低钴羟基氧化镍的放电性能, 结果表明, 含钴1.5%的羟基氧化镍放电性能最为优越, 在60 mA/g放电速率下具有高达280 mA·h/g以上的放电容量。 恒流充放电实验和循环伏安实验表明该羟基氧化镍具有较好的电化学可逆性, 在充放电循环中比容量高达330 mA·h/g。
关键字: NiOOH; 碱性锌镍电池; 放电容量; 电化学性能
( 1. College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China;
2. Faculty of Science, Beijing University of Chemical Technology,
Beijing 100029, China)
Abstract: Highly pure NiOOH was synthesized through one-step oxidizing spherical NiOOH with low cobalt content by highly concentrated mixture of KClO-KOH and followed by rinsing and vacuum desiccating. Structure characterization of the sample by means of scanning electron microscopy, X-ray diffractrometry and laser grain size tester shows that the sample is crystalline of super fine NiOOH with sizes between 220.1-650.9 nm. Three low Co content NiOOH samples are galvanostatically discharged. The results show that the NiOOH containing 1.5% Co has the optimum properties. The discharge capacity is 280 mA·h/g at a discharge rate of 60 mA/g. The tests of charge/discharge and cyclic voltammetry of the prepared NiOOH express good electrochemical reversibility. The specific capacity during charge/discharge reaches as high as 330 mA·h/g.
Key words: NiOOH; alkaline Zn/Ni battery; discharge capacity; electrochemical performance