Preparation and performance of a three-dimensional porous copper-tin electrode for lithium-ion batteries

Abstract

A 3D porous Cu/Sn/Cu6Sn5/Cu3Sn composite anode was successfully fabricated by electrodepositing tin on a copper foam foil and then conducting diffusion heat treatment at 200ºC for 3 h. The specific capacity of the electrode was 660.97 mAh/g at 0.2 C after 300 charge/discharge cycles. The high capacity and cycling stability of the electrode were due to the Cu-Sn phases and porous structure of the copper foam. The formation of the Cu6Sn5 and Cu3Sn phases decreased the tin content on the surface, reduced the volume expansion rate caused by lithiation/delithiation and effectively inhibited the generation of cracks and electrode pulverization. Furthermore, the number of active sites for the reaction between tin and lithium were significantly increased by the uniform distribution of tin on the surface of the copper foam and its large specific surface area.