Yolk-shell Co3O4-CoO/Carbon Composites for Lithium-Ion Batteries with Enhanced Electrochemical Properties

A novel yolk-shell structured Co 3 O 4 -CoO/Carbon (Co 3 O 4 -CoO/C) composite was prepared and applied as cathode active materials in lithium ion batteries. The composites were prepared through a facile copolymerization of ionic liquid and acrylonitrile, which were used as carbon sources, followed by carbonization. The yolk-shell structure of the composite endows the electrodes with excellent cycling performance due to improved electronic conductivity, reduced strain and depressed aggregation of active materials compared with bare Co 3 O 4 . Thus, the Co 3 O 4 -CoO/C composite showed a high reversible capacity and cycling life of 590 mAh·g -1 after 50 charge/discharge cycles at a current rate of 890 mAh·g -1 .