Self-assembled echinus-like nanostructures of mesoporous CoO nanorod@CNT for lithium-ion batteries

Abstract

Development of an electrode material with high capacity and good cyclability at a high charge and discharge rate, has become an important issue for present battery technology. Most electrode materials exhibit reduced capacity and larger capacity fading at high rates. We report a self-assembled echinus-like nanostructure consisting of mesoporous CoO nanorod@carbon nanotube core–shell materials in this work, which exhibits high capacities and excellent cycling performances at various high and low current rates, when used as anode materials for rechargeable lithium ion batteries. In particular, this core–shell nanostructure shows high capacities (703–746 mAh g−1 in 200 cycles) and a long cycle life (0.029% capacity loss per cycle) at a high current rate (3580 mA g−1). The excellent electrochemical energy storage should be attributed to the increased electrical conductivity, mechanical stability and electrochemical activity of porous CoO materials in the presence of a carbon nanotube overlayer.