Tetrathiafulvalene-Based Metal-Organic Framework as a High-Performance Anode for Lithium-Ion Batteries.

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.