Highly reversible Co3O4/graphene hybrid anode for lithium rechargeable batteries

Abstract A Co 3 O 4 /graphene hybrid material was fabricated using a simple in situ reduction process and demonstrated as a highly reversible anode for lithium rechargeable batteries. The hybrid is composed of 5 nm size Co 3 O 4 particles uniformly dispersed on graphene, as observed by transmission electron microscopy, atomic force microscopy, Raman spectroscopy and X-ray diffraction analysis. The Co 3 O 4 /graphene anode can deliver a capacity of more than 800 mA h g −1 reversibly at a 200 mA g −1 rate in the voltage range between 3.0 and 0.001 V. The high reversible capacity is retained at elevated current densities. At a current rate as high as 1000 mA g −1 , the Co 3 O 4 /graphene anode can deliver more than 550 mA h g  −1 , which is significantly higher than the capacity of current commercial graphite anodes. The superior electrochemical performance of the Co 3 O 4 /graphene is attributed to its unique nanostructure, which intimately combines the conductive graphene network with uniformly dispersed nano Co 3 O 4 particles.