Mesoporous CoO@CdS nanorods as anode for high-performance lithium ion batteries with improved lithium storage capacity and cycle life.

Transition metal oxides based anodes are facing crucial problems of capacity fading at long cycles and high rates due to electrode degradations. In this prospective, an effective strategy is employed to develop advanced electrode materials for lithium-ion batteries (LIBs). In the present work, a mesoporous CoO@CdS hybrid sructure is developed and investigated as anode for LiBs. The hybrid structure owning porous nature and large specific surface area, provides an opportunity to boost the lithium storage capabilities of CoO nanorods. The CoO@CdS electrode delivers an initial discharge capacity of 1292 mA h g at 0.1C and a very stable reversible capacity of 760 mA h g over 200 cycles with a capacity retention rate of 92.7%. In addition, the electrode exhibits excellent cyclic stability even after 800 cycles and good rate performance as compared to previously reported electrodes. Moreover, density functional theory (DFT) and electrochemical impedance spectroscopy (EIS) confirm the enhanced kinetics of the CoO@CdS electrode. The efficient performance of the electrode may be due to the increased surface reactivity, abundant active sites/interfaces for rapid Li ion diffusion and the synergy between CoO and CdS NPs. This work demonstrates that CoO@CdS hybrid structures have great potential for high performance batteries.