Bai Jing, Wang Kaiqi, Feng Jinkui, Xiong Shenglin
Key Laboratory for Colloid and Interface Chemistry, Ministry of Education, and School of Chemistry and Chemical Engineering, Shandong University , Jinan 250100, P. R. China.
Institute of Physical Chemistry, Zhejiang Normal University , Jinhua 321004, China.
ACS Appl Mater Interfaces. 2015 Oct 21;7(41):22848-57. doi: 10.1021/acsami.5b05303. Epub 2015 Oct 9.
Mastery over the structure of nanoscale materials can effectively tailor and regulate their electrochemical properties, enabling improvement in both rate capability and cycling stability. We report the shape-controlled synthesis of novel mesoporous bicomponent-active ZnO/CoO hierarchical multilayered bipyramid nanoframes (HMBNFs). The as-synthesized micro/nanocrystals look like multilayered bipyramids and consist of a series of structural units with similar frames and uniform sheet branches. The use of an appropriate straight-chain monoalcohol was observed to be critical for the formation of HMBNFs. In addition, the structure of HMBNFs could be preserved only in a limited range of the precursor ratio. An extremely fast crystal growth process and an unusual transverse crystallization of the ZnCo-carbonate HMBNFs were newly discovered and proposed. By calcination of ZnCo-carbonate HMBNFs at the atmosphere of nitrogen and air, ZnO/CoO and ZnCo2O4 HMBNFs were obtained, respectively. Compared to the ZnCo2O4 HMBNFs, the ZnO/CoO HMBNFs with a uniform distribution of nanocrystal ZnO and CoO subunits exhibited enhanced electrochemical activity, including greater rate capability and longer cycling performance, when evaluated as an anode material for Li-ion batteries. The superior electrochemical performance of the ZnO/CoO HMBNFs is attributed to the unique nanostructure, bicomponent active synergy, and uniform distribution of ZnO and CoO phases at the nanoscale.
对纳米级材料结构的掌控能够有效调整和调控其电化学性质，从而提高倍率性能和循环稳定性。我们报道了新型介孔双组分活性ZnO/CoO分级多层双棱锥纳米框架（HMBNFs）的形状控制合成。所合成的微/纳米晶体形似多层双棱锥，由一系列具有相似框架和均匀片状分支的结构单元组成。观察到使用合适的直链一元醇对于HMBNFs的形成至关重要。此外，HMBNFs的结构仅能在前体比例的有限范围内得以保留。新发现并提出了ZnCo-碳酸盐HMBNFs的极快速晶体生长过程和不寻常的横向结晶。通过在氮气和空气气氛中对ZnCo-碳酸盐HMBNFs进行煅烧，分别获得了ZnO/CoO和ZnCo2O4 HMBNFs。与ZnCo2O4 HMBNFs相比，具有均匀分布的纳米晶体ZnO和CoO亚基的ZnO/CoO HMBNFs在作为锂离子电池负极材料进行评估时，表现出增强的电化学活性，包括更高的倍率性能和更长的循环性能。ZnO/CoO HMBNFs优异的电化学性能归因于其独特的纳米结构、双组分活性协同作用以及ZnO和CoO相在纳米尺度上的均匀分布。
