Weng Yi-Gang, Yin Wen-Yu, Jiang Miao, Hou Jin-Le, Shao Jie, Zhu Qin-Yu, Dai Jie
College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P. R. China.
School of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059, P. R. China.
ACS Appl Mater Interfaces. 2020 Nov 25;12(47):52615-52623. doi: 10.1021/acsami.0c14510. Epub 2020 Nov 10.
Metal-organic frameworks (MOFs) have aroused great interest as lithium-ion battery (LIB) electrode materials. In this work, we first report that a pristine three-dimensional tetrathiafulvalene derivatives (TTFs)-based zinc MOF, formulated [Zn(py-TTF-py)(BDC)]·2DMF·HO () (py-TTF-py = 2,6-bis(4'-pyridyl)tetrathiafulvalene and HBDC = terephthalic acid), can work as a high-performance electrode material for rechargeable LIBs. The TTFs-Zn-MOF electrode displayed a high discharge specific capacity of 1117.4 mA h g at a current density of 200 mA g after 150 cycles along with good reversibility. After undergoing elevated discharging/charging rates, the electrode showed superior lithium storage performance in the extreme case of 20 A g and could finally recover the capability when the current rate was back to 200 mA g. Particularly, specific capacities of 884.2, 513.8, and 327.8 mA h g were reached at high current densities of 5, 10, and 20 A g after 180, 175, and 300 cycles along with good reversibility, respectively. Such an excellent performance is first reported for the LIB anode materials. TTFs-Zn-MOF , namely, [Zn(py-TTF-py) (BDC)]·DMF·2HO (), was prepared as a contrast to explore the relationship between the structures of the electrode materials and the electrochemical properties. Based on the structural analysis of and and ex situ X-ray photoelectron spectroscopy, the TTF moiety and the twofold TTF pillar play a key role in the excellent electrochemical performance. The full cell of MOF with NMC 622 delivered the capacity of 131.9 mA h g at 100 mA g with the Coulombic efficiency of 99.45% after 70 cycles and exhibited the tolerance to high-current operation.
金属有机框架材料（MOFs）作为锂离子电池（LIB）电极材料引起了极大的关注。在本工作中，我们首次报道了一种基于原始三维四硫富瓦烯衍生物（TTFs）的锌基MOF，化学式为[Zn(py-TTF-py)(BDC)]·2DMF·H₂O （）（py-TTF-py = 2,6-双(4'-吡啶基)四硫富瓦烯，HBDC = 对苯二甲酸），可作为可充电LIBs的高性能电极材料。TTFs-Zn-MOF电极在150次循环后，在200 mA g的电流密度下显示出1117.4 mA h g的高放电比容量，且具有良好的可逆性。在经历了更高的充放电速率后，该电极在20 A g的极端情况下表现出优异的锂存储性能，当电流速率恢复到200 mA g时最终能够恢复其性能。特别是，在180、175和300次循环后，在5、10和20 A g的高电流密度下分别达到了884.2、513.8和327.8 mA h g的比容量，且具有良好的可逆性。这种优异的性能首次在LIB负极材料中报道。制备了TTFs-Zn-MOF ，即[Zn(py-TTF-py)(BDC)]·DMF·2H₂O （）作为对比，以探索电极材料结构与电化学性能之间的关系。基于对 和 的结构分析以及非原位X射线光电子能谱，TTF部分和双TTF支柱在优异的电化学性能中起关键作用。MOF 与NMC 622的全电池在100 mA g下70次循环后容量为131.9 mA h g，库仑效率为99.45%，并表现出对高电流操作的耐受性。
