Co₃O₄ nanostructures with a high rate performance as anode materials for lithium-ion batteries, prepared via book-like cobalt-organic frameworks

The self-assembly of cobalt coordination frameworks (Co-CPs) with a two-dimensional morphology is demonstrated by a solvothermal method. The morphology of the Co-CPs has been controlled by various solvothermal conditions. The two-dimensional nanostructures agglomerated by Co₃O₄ nanoparticles remained after the pyrolysis of the Co-CPs. The as-synthesized Co₃O₄ anode material is characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge-discharge measurements. The morphology of Co₃O₄ plays a crucial role in the high performance anode materials for lithium batteries. The Co₃O₄ nanoparticles with opened-book morphology deliver a high capacity of 597 mA h g^-1 after 50 cycles at a current rate of 800 mA g^-1. The opened-book morphology of Co₃O₄ provides efficient lithium ion diffusion tunnels and increases the electrolyte/Co₃O₄ contact/interfacial area. At a relatively high current rate of 1200 mA g^-1, Co₃O₄ with opened-book morphology delivers an excellent rate capability of 574 mA h g^-1.