Mesoporous cobalt monoxide nanorods grown on reduced graphene oxide nanosheets with high lithium storage performance

Graphene-based hybrid nanostructures could offer many opportunities for improved lithium storage performance. Herein, we report a facile synthesis of mesoporous CoO nanorods (CoO NRs) on a reduced graphene oxide (rGO) substrate by hydrothermal and calcination treatment. Transmission electron microscopy (TEM) investigation reveals that the Co NRs with a diameter of 20-60 nm are tightly anchored on the surface of rGO sheets. Compared to pure CoO NRs, the COO NRs/rGO composite shows higher lithium storage capacity and superior rate capability as anode materials for Li-ion batteries. The CoO NRs/rGO composite delivers an initial discharge capacity of 1452 mAh g(-1), and it can still remains 960 mAh g(-1) after 50 cycles at 0.1 A g(-1). After each 10 cycles at 0.1, 0.2, 0.5, and 1 A g(-1), the specific capacities of the composite are about 1096, 1049, 934 and 513 mAh g(-1), respectively. The enhanced electrochetnical performance of the composite is closely related to its unique structure, such as 1D mesoporous morphology of CoO NRs and its tightly-contacting with rGO nanosheets, which could shorten the transport pathway for both electrons and ions, enhance the electrical conductivity and accommodate the volume expansion during prolonged cycling. (C) 2014 Elsevier Ltd. All rights reserved.