N-doped Carbon Coated CoO Nanowire Arrays Derived from Zeolitic Imidazolate Framework-67 as Binder-free Anodes for High-performance Lithium Storage.

To realize large lithium storage capacity and excellent rate capability lithium ion batteries, highly electrochemically active materials and rational design of structure are desirable. Here, we successfully synthesized CoO@N-doped carbon nanowire arrays derived from zeolitic imidazolate frameworks-67 (ZIF-67) on Ni foam (denoted as CoO@N-C/NF). Each CoO@N-C nanowire was built up of numerous ordered in-situ nitrogen-doped carbon coated CoO nanoparticles (around 20 nm) after annealing treatment. Benefited from the unique structural features, when served as anode for lithium ion batteries, the CoO@N-C/NF exhibit superior initial Coulombic efficiency of 78.04%, and excellent electrochemical cyclability (1884.1 mAh g at 1 A g after 100 cycles) and good rate capability (1169.2 mAh g at the rate of 5000 mA g). To our knowledge, this is the highest capacity with similar electric current density that has been reported for CoO-based materials. Our results indicate that the CoO@N-C/NF electrode without any auxiliary materials are expected to open up new opportunities for CoO-based material to power electronic devices.