Composite lithium battery anodes based on carbon@Co3O4 nanostructures: Synthesis and characterization

We report on the formation of carbon/Co3O4 (C@Co3O4) composite nanospheres using a hydrothermal approach, followed by application of a thin coating of monosaccharide-derived carbon veneered on the surface of Co3O4 by high temperature calcination. When evaluated as the negative electrode for Li-ion batteries (LIBs), the C@Co3O4 structures exhibit attractive energy storage capacity and improved cycle life, over more than 100 repeated discharge/charge cycles. We hypothesize that the improved electrochemical performance of the composite electrodes originates from the enhanced structural stability of the active Co3O4 particles, imparted by the carbon coating. Consistent with this hypothesis, post mortem analysis performed on pristine Co3O4 and composite C@Co3O4 anodes subjected to prolonged cycling indicate that surface cracking, particle breakage, and primary particle fusion evident in the pristine Co3O4 material are substantially reduced in anodes comprised of C@Co3O4.

► A facile hydrothermal method has been used to synthesize monodispersed C@Co3O4.
► Monosaccharide-derived carbon has been veneered on Co3O4 at high temperature.
► When used as anode in LIB, C@Co3O4 revealed excellent capacity over 100 cycles.
► Charge/discharge studies carried out at various C-rates showed enhanced capacity.
► Rise in capacity justified using electrode postmortem analysis after 100 cycles.