Three-dimensional Porous Cu6Sn5 Alloy Anodes for Lithium-ion Batteries

Three-dimensional porous Cu6Sn5 alloy electrodes were prepared by electroplating using copper foam as the current collector. The micro-holes and small islands on surface of the Cu6Sn5 alloy largely increased the surface area of the electrode, and significantly improved the ability of the electrode in buffering the volume change in the process of charge/discharge when the Cu6Sn5 alloy was employed as the anode in a lithium-ion battery. Galvonostatic charging/discharging results demonstrated that the initial discharge (lithiation) and charge (delithiation) specific capacities of the Cu6Sn5 alloy electrode were 620 mAh·g−1 and 560 mAh·g−1, respectively. It demonstrated that the Cu6Sn5 alloy electrode exhibited a large initial coulomb efficiency (90.3%) and good capacity retention. Scanning electron microscopy (SEM) results illustrated that the Cu6Sn5 alloy deposited on copper foam substrate was more stable than that on a conventional copper substrate, and displayed no obvious exfoliation after 50 charge/discharge cycles.