控制化学结晶法制备球形Ni(OH)_2的热力学分析  

Thermodynamic analysis of the preparation of spherical Ni(OH)_2 by controlled chemical crystallization

作　　者：顾琳[1] 王剑华[1] 郭玉忠[1] 刘浪[1] 

机构地区：[1]昆明理工大学材料科学与工程学院,云南昆明650093

出　　处：《南方金属》2010年第2期10-14,共5页Southern Metals

基　　金：云南省自然科学基金项目(KKS200727021)

摘　　要：对于控制化学结晶法制备镍氢电池正极球形氢氧化镍材料，确定反应体系完全沉淀区域是确保高活性、高密度电极材料的关键．利用材料热力学理论、扫描电子显微镜（SEM）、电化学测试对反应体系pH值与球形氢氧化镍表面形貌、晶粒尺寸、堆积密度及放电比容量的关系进行研究．结果表明：当pH值在9．5—11．5时，反应体系处于热力学平衡态，镍离子在氨水络合剂作用下完全沉淀，其溶解度随pH值的增加呈先减小后增大的趋势．在pH=11时制备得球形氢氧化镍兼具高密度高活性．In order to prepare spherical nickel hydroxide for MH - Ni battery cathode materials by means of controlled chemical crystallization,determination of the system＇ s complete precipitation regime is crucial for making a high density and high activity material. The surface morphology, grain size, bulk density, electrochemical properties and pH value of the spherical nickel hydroxide crystallites were characterized by means of thermodynamic analysis, SEM and electrochemical analysis. The results showed that with a pH value of 9. 5 - 11.5, the reaction system attained an equilibrium condition, and the nickel ions,while being complexed with NH3, could be completely precipitated as NiOH. With increasing the pH value, the solubility of the nickel hydroxide first decreased and then increased. The material is high in density and activity when pH = 11.

关 键 词：控制化学结晶 球形氢氧化镍 PH值 热力学 

分 类 号：TG146.15[一般工业技术—材料科学与工程]