Metal-Organic Frameworks Mediated Synthesis of One-Dimensional Molybdenum-Based/Carbon Composites for Enhanced Lithium Storage
Metal-Organic Frameworks Mediated Synthesis of One-Dimensional Molybdenum-Based/Carbon Composites for Enhanced Lithium Storage
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DOI：
10.1021/acsnano.7b09175
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发表时间：
2018-02-01
期刊：
影响因子：
17.1
通讯作者：
Wu, Mingbo
中科院分区：
文献类型：
--
作者：
Tian, Wei;Hu, Han;Wu, Mingbo
具有适当工程纳米结构的钼（Mo）基化合物通常具有改善的可逆锂存储能力，这为提高锂离子电池（LIB）的性能提供了很大的希望。然而，缺乏有效和高产率的方法来构建合理的纳米结构，在很大程度上限制了这些潜在的重要材料的应用。在此，我们展示了一种金属有机框架（MOFs）介导的策略，成功地合成了一系列具有不同纳米结构的一维钼基/碳复合材料。该工艺从精心设计的MoO 3纳米棒出发，首先提出晶体控制生长，实现在MoO 3表面可控生长一层MOFs，形成明显的核壳结构，然后采用不同温度下直接碳化，使所采用的前驱体原位转化为MoO 2或Mo 2C，二者均被很好地约束在导电多孔炭中，其中MOF壳既充当碳源又充当反应物以同时与MoO 3反应。受益于这种设计，当作为LIB的阳极材料进行评估时，所有优化的产品都表现出增强的电化学性能，特别是中空MoO 2/C和核-壳Mo 2C/C电极，即使在1A g（-1）的电流密度下600次循环后，也分别显示出高达810和530 mAh g（-1）的最佳可逆容量。因此，本工作将拓宽MOFs作为一种包覆材料的应用范围，并阐明钼基化合物的储锂性能。
Molybdenum (Mo)-based compounds with properly engineered nanostructures usually possess improved reversible lithium storage capabilities, which offer great promise to boost the performance of lithium-ion batteries (LIBs). Nevertheless, a lack of efficient and high-yield methods for constructing rational nanostructures has largely restricted the application of these potentially important materials. Herein we demonstrate a metal-organic frameworks (MOFs) mediated strategy to successfully synthesize a series of one-dimensional Mo-based/carbon composites with distinct nano structures. In this process, starting from well-designed MoO3 nanorods, the crystal control growth is first proposed that a layer of MOFs is achieved to be controllably grown on surfaces of MoO3, forming an obvious core-shell structure, and then the adopted precursor can be in situ transformed into MoO2 or Mo2C which are both well confined in conductive porous carbons through direct carbonization at different temperatures, where the MOFs shell serve as both carbon sources and the reactant to react with MoO3 simultaneously. Benefiting from this design, all optimized products exhibit enhanced electrochemical performances when evaluated as anode materials for LIBs, especially the hollow MoO2/C and core-shell Mo2C/C electrodes, show best reversible capacities up to 810 and 530 mAh g(-1) even after 600 cycles at a current density of 1 A g(-1), respectively. So this work may broaden the application of MOFs as a kind of coating materials and elucidates the attractive lithium storage performances of molybdenum -based compounds.