Synthesis, Structure and Lithium Storage Performance of a Copper-Molybdenum Complex Polymer Based on 4,4’-bipyridine

Abstract A novel bimetal organic complex polymer (MOCP) with the molecular formula C20H16Cu2MoN4O4 (shortened as bpyMoCu2) was prepared by hydrothermal synthesis, and the structure was revealed by single crystal X-ray diffraction. BpyMoCu2 shows one-dimensional structure that is made up of copper and molybdenum atoms as nodes (the molar ratio Cu:Mo = 2:1) being bonded with 4,4'-bipyridine (4,4'-bipy) ligand as linker. It is worth mentioning that copper is coordinated by three atoms and molybdenum is coordinated by four O atoms, which provide a large number of active sites around them (Cu and Mo). BpyMoCu2 shows a rectangular parallelepiped mesoporous morphology, which is more conductive for lithium ion to transfer at electrode/electrolyte interface. As an anode material of lithium ion batteries (LIBs), bpyMoCu2 shows an ultra-high capacity of 1628.6 mAhg-1 for the first cycle at a current density of 100 mAg-1, and the capacity could still be maintained at 805.4 mAhg-1 after 100 cycles. Besides, bpyMoCu2 shows an excellent rate performance due to the one-dimensional (1D) structure and synergistic lithium storage mechanisms.