Bimetal-Organic Framework: One-Step Homogenous Formation and its Derived Mesoporous Ternary Metal Oxide Nanorod for High-Capacity, High-Rate, and Long-Cycle-Life Lithium Storage

Metal-organic frameworks (MOFs) and relative structures with uniform micro/mesoporous structures have shown important applications in various fi elds. This paper reports the synthesis of unprecedented mesoporous NixCo3-xO4 nanorods with tuned composition from the Co/Ni bimetallic MOF precursor. The Co/Ni-MOFs are prepared by a one-step facile microwaveassisted solvothermal method rather than surface metallic cation exchange on the preformed one-metal MOF template, therefore displaying very uniform distribution of two species and high structural integrity. The obtained mesoporous Ni0.3Co2.7O4 nanorod delivers a larger-than-theoretical reversible capacity of 1410 mAh g(-1) after 200 repetitive cycles at a small current of 100 mA g(-1) with an excellent high-rate capability for lithium-ion batteries. Large reversible capacities of 812 and 656 mAh g(-1) can also be retained after 500 cycles at large currents of 2 and 5 A g(-1), respectively. These outstanding electrochemical performances of the ternary metal oxide have been mainly attributed to its interconnected nanoparticle-integrated mesoporous nanorod structure and the synergistic effect of two active metal oxide components.