Cheng Qiuxia, Pan Yingying, Chen Yueying, Zeb Akif, Lin Xiaoming, Yuan Zhongzhi, Liu Jincheng
Guangzhou Key Laboratory of Materials for Energy Conversion and Storage, Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, School of Chemistry, South China Normal University, Guangzhou 510006, P. R. China.
School of Environment and Energy, South China University of Technology, Guangzhou 510006, Guangdong, P. R. China.
Inorg Chem. 2020 Sep 8;59(17):12700-12710. doi: 10.1021/acs.inorgchem.0c01783. Epub 2020 Aug 10.
A comprehensive strategy for the morphological control of octahedral and spindle Fe-based metal-organic frameworks (Fe-MOFs) via microwave-assisted adjustment is proposed in this research. Afterward, in situ copyrolysis under N atmosphere contributes to the fabrication of two shape-maintained FeF·0.33HO nanostructures (named O-FeF·0.33HO and S-FeF·0.33HO, respectively) with confined hierarchical porosity and graphitized carbon skeleton. The lithium storage performances for the MOF-derived octahedral O-FeF·0.33HO and spindle S-FeF·0.33HO composites are investigated, and the prospective lithium storage mechanism is discussed. As a result, the main product of the porous O-FeF·0.33HO structure is found to be a promising cathode material for lithium ion batteries owing to its advantageous electrochemical capability. Even after being cycled over 1000 times at 2 C (1 C = 237 mAh g), the capacity attenuation rate of the as-prepared O-FeF·0.33HO electrode is as low as 0.039% per cycle. The combination of proper octahedral morphology and highly graphitized carbon modification can not only enhance the conductivity of the cathode but also promote the diffusion of Li effectively. The remarkable performance of octahedral O-FeF·0.33HO can be confirmed by the Li-ion diffusion coefficient () calculation analysis and kinetics analysis of lithium storage behavior.
本研究提出了一种通过微波辅助调控对八面体和纺锤体状铁基金属有机框架（Fe-MOFs）进行形态控制的综合策略。随后，在N气氛下进行原位共热解有助于制备两种具有受限分级孔隙率和石墨化碳骨架的形状保持的FeF·0.33HO纳米结构（分别命名为O-FeF·0.33HO和S-FeF·0.33HO）。研究了MOF衍生的八面体O-FeF·0.33HO和纺锤体状S-FeF·0.33HO复合材料的储锂性能，并讨论了潜在的储锂机制。结果发现，多孔O-FeF·0.33HO结构的主要产物因其有利的电化学性能而成为一种有前景的锂离子电池正极材料。即使在2 C（1 C = 237 mAh g）下循环1000次后，所制备的O-FeF·0.33HO电极的容量衰减率也低至每循环0.039%。适当的八面体形态与高度石墨化碳修饰的结合不仅可以提高正极的导电性，还能有效促进Li的扩散。八面体O-FeF·0.33HO的优异性能可以通过锂离子扩散系数（）计算分析和储锂行为的动力学分析得到证实。
