Si nanorod arrays modified with metal-organic segments as anodes in lithium ion batteries
Si nanorod arrays modified with metal-organic segments as anodes in lithium ion batteries
复制标题
用金属有机片段修饰的硅纳米棒阵列作为锂离子电池的阳极
DOI：
10.1039/c7ra10905a
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发表时间：
2017
期刊：
影响因子：
3.9
通讯作者：
Kang Junyong
中科院分区：
文献类型：
--
作者：
Yu Yingjian;Yue Chuang;Han Yingzi;Zhang Chuanhui;Zheng Mingsen;Xu Binbin;Lin Shuichao;Li Jing;Kang Junyong
可控合成金属有机链段（MOS）与硅纳米棒（NR）阵列复合作为锂离子电池（LIB）电极。这类MOS被认为是来自溶液物种，如[Zn（C4 H6 N2）Ac]+、[Zn（C4 H6 N2）2Ac]+和[Zn（C3 H4 N2）（C4 H6 N2）Ac]+，如通过电喷雾电离飞行时间质谱（ESI-TOF-MS）检测的。研究发现，溶液浓度和生长时间对硅核反应器周围的MOS涂层有显著的影响。在相对较低的溶液浓度或较短的生长时间下，已成功地在Si NR周围产生了均匀的MOS涂层，这被证明有助于在10 μA cm− 2的电流密度下将复合电极的容量提高到1.1 mA h cm−2，并且在将电流密度增加到50 μA cm− 2时提高到1.5 mA h cm− 2。此外，在200 μA cm-2的更高电流密度下（与初始10 μA cm-2相比），复合电极仍然可以保持超过50%的初始容量。然而，如果溶液浓度较高或反应时间较长，则会在Si NR的顶部形成大的ZIF-61晶体，这是一种金属有机骨架（MOF）。与MOS不同的是，ZIF-61晶体不能均匀地覆盖在Si NR上，因此ZIF-61/Si NR复合电极的容量远低于MOS/Si NR电极。这项工作不仅展示了一种简单的方法，硅表面改性，以提高其相应的电化学性能，但也提供了一个潜在的通用策略，通过金属节点和有机配体的交联不同的表面涂层。
Metal–organic segments (MOSs) have been controllably synthesized to composite with Si nanorod (NR) arrays as electrodes in lithium ion batteries (LIBs). These kinds of MOSs are suggested to be derived from solution species such as [Zn(C4H6N2)Ac]+, [Zn(C4H6N2)2Ac]+ and [Zn(C3H4N2)(C4H6N2)Ac]+ as detected by electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS). It is found that solution concentration and growth time have significant effects on the MOS coating around Si NRs. The uniform coating of MOSs around Si NRs has been successfully produced at relatively low solution concentrations or for shorter growth time, which was proved to be helpful to enhance the capacity of the composite electrode up to ∼1.1 mA h cm−2 at a current density of 10 μA cm−2 and ∼0.5 mA h cm−2 on increasing the current density to 50 μA cm−2. Furthermore, at an even higher current density of 200 μA cm−2 (vs. initial 10 μA cm−2) the composite electrodes still can maintain more than 50% of the initial capacities. While, given a higher solution concentration or longer reaction time, large ZIF-61 crystals, a kind of metal–organic framework (MOF), would form on the top of Si NRs. Unlike MOSs, large ZIF-61 crystals fail to cover the Si NR homogeneously, and consequently the capacities of ZIF-61/Si NR composite electrodes are much lower than those of MOS/Si NR electrodes. This work not only demonstrates a simple method for Si surface modification to enhance its corresponding electrochemical performance, but also provides a potential general strategy for the coating of different surfaces by the cross-linking of metal nodes and organic ligands.