Self-assembled hairy ball-like Co3O4 nanostructures for lithium ion batteries

Abstract

Nanostructured Co₃O₄ in a novel hairy ball-like morphology is successfully synthesized from self-assembled hierarchical Co(CO₃)_0.35Cl_0.2(OH)_1.10·1.74H₂O precursors via a facile hydrothermal method and subsequent annealing in air. The morphological evolution of the Co(CO₃)_0.35Cl_0.2(OH)_1.10·1.74H₂O precursors is investigated by examining the different reaction times during the synthesis. First, fan-shaped microplates are formed, followed by nanowires grown on the surface of the plates. Subsequently, with an extended growth reaction time, the nanowires grow longer to form the hairy ball-like structures. The Co₃O₄, obtained from thermal decomposition of the Co(CO₃)_0.35Cl_0.2(OH)_1.10·1.74H₂O precursor in air at 400 °C, exhibits highly reversible capacities as an anode material in lithium ion batteries, which retains 860 mA h g⁻¹ at 100 mA g⁻¹ after 50 cycles, with good cycling stabilities and rate capabilities.