Cobalt oxide nanoparticles anchored on discharged-graphene film for lithium-ion battery

Abstract

In order to improve lithium storage capacity and cycle stability of the electrode materials, the combination of the active material and graphene is an effective way. Reduced graphene oxide (rGO) film on Ti substrate is obtained in an aqueous graphene oxide solution using a two-electrode constant voltage electrodeposition system. Then the rGO film on Ti substrate is used as working electrode to assemble lithium-ion batteries and discharged to 0.01 V. The discharged rGO film further reacts with cobalt ions in the cobalt acetate aqueous solution to fabricate the cobalt oxide (CoO)/rGO-precursor, and subsequently the CoO/rGO-700 composite is obtained by calcining the precursor at 700 °C under N2. Different measurements are conducted to evaluate the samples. The CoO/rGO-700 composites are further used as electrode material of lithium-ion batteries, which deliver an initial capacity of 1290.6 mAh·g−1 at 100 mA·g−1. For the first time, the synthetic method reported in this work can be extended to the synthesis of other metal or oxide/rGO composites.