Synthesis of metal shell on metal oxides nanowires forming composite core/branch arrays with enhanced electrochemical properties

Abstract In this work, we develop a facile electro-deposition method to assemble Co ultrathin shell on the Co 3 O 4 nanowires forming Co 3 O 4 @Co core/branch arrays (CBAs). Co nanoshell of 5–10 nm is homogeneously connected with each other and forms a conductive “armor” on the Co 3 O 4 nanowires. Attractive advantages including high electronic conductivity and large porosity are combined in the designed core/branch architecture. Compared with the unmodified Co 3 O 4 nanowires, the Co 3 O 4 @Co CBAs have been demonstrated with higher capacity and better cycling stability. A specific capacity of 649 mAh g −1 is obtained for the Co 3 O 4 @Co electrode at 3 A g −1 , much higher than that (431 mAh g −1 ) of the Co 3 O 4 nanowires counterpart. In addition, after 300 cycles at 0.25 A g −1 , the Co 3 O 4 @Co electrode delivers a stable capacity of 863 mAh g −1 , better than the pristine Co 3 O 4 counterpart (686 mAh g −1 ) owing to better conductive networks and more stable electrode structure.