Sn–Co alloy anode using porous Cu as current collector for lithium ion battery

Porous Cu was prepared by electrodepositing Cu on a Cu foil using hydrogen bubbles as dynamic template, followed annealing at appropriate conditions to strengthen the adhesion between the porous Cu layer and the Cu foil substrate. Sn–Co alloy was then electrodeposited on the porous Cu substrate which served as current collector to be used as anode of lithium ion battery. X-ray diffraction (XRD) and EDS analysis indicated that the Sn–Co alloy was an intermetallic compound of CoSn3, whose surface structure is stable as illustrated by scanning electronic microscopy (SEM) images obtained before and after electrochemical cycles. It has also revealed that the Sn–Co alloy anode on the porous Cu substrate possessed a relative large capacity and a superior cycleability than that of the Sn–Co alloy anode on the smooth Cu sheet. The first discharge and charge capacities were measured respectively at 726 and 563 mAh g−1, and its capacity in the 50th cycle was retained at ca. 71% of that in the second cycle, which has been improved more than 3 times higher of that of the Sn–Co alloy anode on the smooth Cu sheet under the same conditions.