Excellent performance in lithium-ion battery anodes: Rational synthesis of Co(CO3)0.5(OH)0.11H2O nanobelt array and its conversion into mesoporous and single-crystal Co3O4

Abstract

Herein, we report a rational method to synthesize a Co3O 4 nanobelt array on a conducting substrate and functionalize it in the application of Li-ion battery anodes, which is a novel and facile approach to access the nanobelt array of transition metal oxides. Compared to the previous reports, the as-prepared samples in our experiments exhibited both mesoporosity and single-crystallinity, and meanwhile, good contact with the conducting substrate (via a thin layer of TiO2) provided an express pathway for charge transfer when they were applied in Li-ion batteries without any need to add other ancillary materials (carbon black or binder) to enhance the system's conductivity and stability. Under the condition of high charge-discharge current density of 177 mA/ g in Li-ion batteries' testing, the Co3O4 nanobelt array was capable of retaining the specific capacity of 770 mAh/ g over 25 cycles. Moreover, even though the charge-discharge rates were increased to 1670 and 3350 mA/g, it still could have reached the stable retention of the specific capacity of 510 and 330 mAh/g beyond 30 cycles, respectively, indicating an obtainable excellent rate capability. More importantly, the improved performance in Liion battery testing was definitely ascribed to the unique structures in our samples after elaborate analysis. So the final conclusion would be given that the lab-synthesized Co3O4 nanobelt array potentially could be a highly qualified candidate for Li-ion battery anodes in some practical fields, where high capacity and good capability are strictly required. © 2010 American Chemical Society.