Synthesis of hierarchical Co3O4@C composite and its lithium storage property as anode material for rechargeable lithium ion batteries

摘要

Carbon coated Co3O4(Co3O4@C) composite with hierarchical architecture is synthesised by hydrothermal and subsequent CH4 chemical vapour deposition method. Based on the results obtained from morphology and structure characterisation, the possible formation process of the hierarchical Co3O4@C has been proposed. As an anode material for lithium ion batteries, Co3O4@C shows an improved electrochemical performance in the initial coulombic efficiency (63%), reversible capacity (775 mAh g(-1) at 30th cycle) and cycling stability (83% capacity retention after 30 cycles). The performance is much better than the results obtained from hierarchical Co3O4 particles. The excellent electrochemical performance of Co3O4@C can be attributed to the thin carbon layers formed over each Co3O4 particle, which enhances the ionic/electrical conductivity, and serves as a buffering agent to absorb the volume expansion during the charge/discharge cycles.