Urchin-like CoO–C micro/nano hierarchical structures as high performance anode materials for Li-ion batteries

Abstract

In this work, urchin-like microspheres consisting of radial carbon-coated cobalt monoxide nanowires are designed, to fabricate a micro/nano hierarchical structure for efficient Li-storage. A sequential conversion process is adopted, involving hydrothermal synthesis of an urchin-like cobalt carbonate hydroxide precursor, glycosidation of glucose as a coating layer, and calcination in an inert atmosphere to form a CoO–C composite. On the one hand, the CoO framework provides a high Li-storage capacity with short transport paths and ordered free spaces. On the other hand, the carbon coating layer buffers the volume expansion of inner active materials during lithiation, while providing a stabilized electrode/electrolyte interface and rapid electronic conduction. When tested as an anode material for lithium ion batteries, the urchin-like CoO–C delivers a reversible capacity of 755 mA h g⁻¹ after 100 cycles. With rate increasing, the performance advantage of the CoO–C composite electrode over a single CoO electrode is obvious.