Characteristic performance of SnO/Sn/Cu6Sn5 three-layer anode for Li-ion battery

To compare cyclic performances of different Sn based materials as anodes for Li ion battery and minimize the influence from processing conditions, the SnO/Sn/Cu6Sn5 three-layer film was prepared by a facile method of annealing the electrodeposited thick Sn film on Cu substrate at 200°C in atmosphere for 48h. Microstructure and morphology of the three-layer film were characterized by X-ray diffraction and SEM. Both the Sn film and three-layer film were assembled as anodes in Li-ion battery. Their electrochemical properties were studied by charge/discharge, cyclic voltammetry and ac impedance spectra. Compared with Sn anode, SnO/Sn/Cu6Sn5 three-layer anode shows much smaller SEI film, charge transfer and diffusion resistance. Capacities of SnO, Sn and Cu6Sn5 phases were obtained from analysis of charge/discharge curves. Among all three phases, Cu6Sn5 shows both the highest capacity and capacity retention.