Growth mechanisms for spherical mixed hydroxide agglomerates prepared by co-precipitation method: A case of Ni1/3Co1/3Mn1/3(OH)2
Growth mechanisms for spherical mixed hydroxide agglomerates prepared by co-precipitation method: A case of Ni1/3Co1/3Mn1/3(OH)2
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DOI：
10.1016/j.jallcom.2014.08.152
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发表时间：
2015-01
影响因子：
6.2
通讯作者：
Yue Yang;Shengming Xu;Ming Xie;Yinghe He;Guoyong Huang;Y. Yang
中科院分区：
文献类型：
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作者：
Yue Yang;Shengming Xu;Ming Xie;Yinghe He;Guoyong Huang;Y. Yang
在氨存在下，采用共沉淀法合成了球形Ni1/3Co1/3Mn1/3(OH)2团聚体。结果表明，球形团聚体的生长机理遵循单晶成核和各向异性生长三个阶段；由单晶粒作为初级颗粒聚集形成胚团聚体的多晶微晶的聚集；通过初始附聚物的附聚、附聚物中单个晶体的持续生长以及初级颗粒的进一步附着，球形附聚物或颗粒的形成、生长和固结。前两个阶段非常快，而最后一个阶段几乎需要整个过程才能完成。 Ni1/3Co1/3Mn1/3(OH)2晶体各向异性生长的主要原因是E(001)、E(100)、E(101)和E(102)晶体表面能不同，其中E(001)最高。最终球形附聚物的形态可以通过接触的初级颗粒的部分重结晶来解释。通过X射线衍射、扫描电子显微镜、透射电子显微镜以及利用密度函数理论计算晶体表面能来研究球形团聚体的生长过程。
Spherical Ni1/3Co1/3Mn1/3(OH)2agglomerates were synthesized by the co-precipitation method in the presence of ammonia. The results show that the growth mechanism of spherical agglomerates follows three-stages, i.e. nucleation and anisotropic growth of single crystals; agglomeration of polycrystalline crystallites agglomerated by single crystal grains as primary particles to form embryonic agglomerates; formation, growth and consolidation of spherical agglomerates or particles by agglomeration of embryonic agglomerates, continued growth of individual crystals in the agglomerates and further attachment of primary particles. The first two stages are very fast while the last stage takes almost the entire process to complete. The main reason for the anisotropic growth of Ni1/3Co1/3Mn1/3(OH)2crystal is that crystal surface energy ofE(001),E(100),E(101)andE(102)is different withE(001)being the highest. The morphology of the final spherical agglomerates is explained by partial re-crystallization of contacting primary particles. The growth process of spherical agglomerates was examined by X-ray diffraction, scanning electron microscope, transmission electron microscope and calculation of crystal surface energy using density function theory.