CAJ | 학술논문

通过扫描电镜(SEM)和透射电镜(TEM)技术研究了在连续搅拌反应沉淀-结晶过程中生成的球形氢氧化镍的微结构形成机制.研究结果表明,在连续搅拌反应器中,小颗粒的聚集为氢氧化镍微粒生长的主要方式,聚集和重结晶过程进而影响球形氢氧化镍颗粒的表面和内部结构;宏观形貌为球形的每一个氢氧化镍微球由纳米片状氢氧化镍沿径向叠砌而成,纳米片状氢氧化镍晶粒之间相互连接形成三维网络结构;氢氧化镍微球表面结构显示由新生纳米晶氢氧化镍自组装聚集特征,同时微球内存在大量的孔隙.具备这种结构的球形氢氧化镍活性物质在Ni-MH电池的充放电过程中可能具有良好的力学稳定性及质子和电子传导性能.
통과소묘전경(SEM)화투사전경(TEM)기술연구료재련속교반반응침정-결정과정중생성적구형경양화얼적미결구형성궤제.연구결과표명,재련속교반반응기중,소과립적취집위경양화얼미립생장적주요방식,취집화중결정과정진이영향구형경양화얼과립적표면화내부결구;굉관형모위구형적매일개경양화얼미구유납미편상경양화얼연경향첩체이성,납미편상경양화얼정립지간상호련접형성삼유망락결구;경양화얼미구표면결구현시유신생납미정경양화얼자조장취집특정,동시미구내존재대량적공극.구비저충결구적구형경양화얼활성물질재Ni-MH전지적충방전과정중가능구유량호적역학은정성급질자화전자전도성능.
The formation of microstructures for spherical Ni(OH)2 particles synthesized by the aqueous precipitation-crystallization process in a continuous stirring-tank reactor(CSTR) has been investigated by scanning electron microscopy(SEM) and transmission electron microscopy(TEM). The growth of spherical Ni(OH)2 particles primarily depends on the aggregation rate in CSTR. It is assumed that the agglomeration acts on the formation of both surface and inner structures of the spherical Ni(OH)2 particles. The surface structure may be formed by the self-assembling coalescence of newly formed nano-crystallites while the inner structure of spherical Ni(OH)2 characterized with radially arranged crystals can be attributed to the re-crystallization processing, which turns reversible aggregations to irreversible integrated agglomerations. The macro-spherical nickel hydroxide particle characterizes with the microstructure, which consists of largely radially arranged plate-like crystallites and among these plate-like crystallites there are full of pores and crannies to form a network structure. This structure will benefit improvements for electrochemical performances of nickel hydroxides as the active positive materials in Ni-MH batteries due to a potential enhancement of proton diffusion and electronic conductivity in the materials and mechanical stability during charge/discharge processes.