Facile synthesis and lithium storage performance of SnO2–Co3O4 core–shell nanoneedle arrays on copper foil

Abstract

Abstract SnO 2 –Co 3 O 4 core–shell nanoneedle arrays are vertically aligned on copper foil by a facile template-free method. Without using any binder, conductive carbon or other ancillary materials, SnO 2 –Co 3 O 4 core–shell nanoneedle arrays on copper foil are directly used as the anodes of lithium battery. At 0.5C rate (2 h per charging cycle), their reversible capacity maintains at ∼985 mA h g −1 after 20 cycles, higher than that of bare Co 3 O 4 nanoneedle arrays (∼813 mA h g −1 ) and pure SnO 2 nanostructures (∼582 mA h g −1 ). Such a high lithium storage capacity can be attributed to the synergistic effect between nanostructured SnO 2 and Co 3 O 4 . Co 3 O 4 nanostructures with high electrochemical activity can activate the irreversible capacity of SnO 2 , and the nanoarray structures can provide good contact, short electron transporting paths, high surface-to-volume ratio and open space in the system. These results indicate that one-dimensional nanocomposite arrays on copper foils are good candidates for the anode of lithium ion battery.