Highly reversible Co3O4/graphene hybrid anode for lithium rechargeable batteries

Abstract

A Co3O4/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 Co3O4 particles uniformly dispersed on graphene, as observed by transmission electron microscopy, atomic force microscopy, Raman spectroscopy and X ray diffraction analysis The Co3O4/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 cur rent rate as high as 1000 mA g, the Co3O4/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 Co3O4/graphene is attributed to its unique nanostructure, which intimately combines the conductive graphene network with uniformly dispersed nano Co3O4 particles.