β-球形氢氧化镍的微观结构及其形成机理  

Microstructures and formation mechanism of spherical β - Ni(OH)_2

作　　者：彭美勋[1] 王零森[1] 沈湘黔[2] 危亚辉[2] 贺万宁[2] 

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083 [2]长沙矿冶研究院,长沙410012

出　　处：《中国有色金属学报》2003年第5期1130-1135,共6页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金重点资助项目 (5 0 13 40 2 0 )

摘　　要：提出了 2种 β 球形氢氧化镍颗粒内切面扫描电镜 (SEM )样品的制备方法。X射线衍射 (XRD)和SEM分析表明 :β 球形氢氧化镍微观结构由大致相同的放射状的片晶叠合组成 ,而片晶大小、球粒外表面形貌是其结晶有序程度的反映 ;结晶有序性差的微细粒状微晶氢氧化镍较结晶有序性好、粗粒片状氢氧化镍具有更好的电化学性能。探讨了 β 球形氢氧化镍微观结构的形成机制 ,认为球粒形貌及结晶有序度可能与氢氧化镍的晶相从α→β的陈化程度有关 :随陈化程度的加深 ,球粒表面微粒形貌从边界模糊的粒状向边界清晰的六方片状转化 ,球粒内部晶片变大 ,XRD特征值 (10 1)面半高宽和晶胞参数c变小 ,In/It 增大。Two methods to prepare the samples for the study of the interior morphologies of spherical β -Ni(OH)_2 by scanning electronic microscopy(SEM) were developed. The microstructures of the spherical β -Ni(OH)_2 with different exterior morphologies were characterized. The sizes of the crystal faces and the exterior morphologies of spherical β -Ni(OH)_2 were associated with the structure regularity characterized by X-ray diffraction(XRD). It is indicated that the spherical β -Ni(OH)_2 with poorly structure regularity exhibits better electrochemical activities than that with better structure regularity. The microstructure is supposed to be related to the ageing process from α-Ni(OH)_2 to β -(Ni(OH)_2.) With the ageing process, morphologies of the spherical β -Ni(OH)_2 may change from the particle-like to the layer-like and the interior crystalline faces might become larger with the phase change for Ni(OH)_2.

关 键 词：纳米材料 镍氢电池 正极材料 电化学性能 制备 β-球形氢氧化镍 微观结构 陈化 

分 类 号：TM912[电气工程—电力电子与电力传动]