One-Dimensional CoO@C Core–Shell Nanostructures for Improved Lithium Storage Properties.

Abstract

Exploring conversion-type anode materials with large and stable lithium storage properties as well as good rate performance still remains a great challenge. This work presents one-dimensional core–shell CoO@C nanostructures as high-performance anode materials for lithium ion batteries. TEM measurements show that interior voids and carbon shell can be observed in the core–shell nanostructures. Electrochemical impedance spectroscopy reveals that the coated carbon layer can remarkably reduce the charge transfer resistance of the electrochemical conversion reaction. Endowed with the combined advantages mentioned above, the present sample exhibits good electrochemical properties when tested as anode materials, such as high and stable lithium storage properties (877.2 mAh g⁻¹ after 100 cycles at 100 mA g⁻¹ and 661.5 mAh g⁻¹ after 500 cycles at 1 A g⁻¹), superior rate performance, and long cycling life (over 500 cycles at high current density of 1 A g⁻¹). These good performances make it a promising candidate for high-performance anode materials.