In this work we investigate by impedance spectroscopy the characteristics of a film formed on the surface of Sn electrodes when cycled in a lithium cell. We show that this film is formed by electrolyte decomposition catalyzed by the tin surface and that its characteristics depend upon cycling rate as reported in the literature. By the infrared analysis we study the chemical characteristic of mentioned film. By reporting the cycling response of a complete lithium-ion battery using a Sn anode coupled with a LiNi0.5Mn1.5O4 cathode, we show that the interfacial film may indeed influence the response of the batteries using conventional, tin-based anodes.