Preparation and capacity fading mechanism of tin thin film as anode of lithium-ion battery

Abstract

Tin thin film coated on Cu substrate as anode of lithium-ion battery was prepared by electroplating. Its structure and properties were characterized and studied by X-ray diffration, scanning electron microscopy, cyclic voltammetry, charging/discharging test and AC impedence method. XRD patterns indicate that the tin thin film exhibits a structure of tetragonal crystal. The first discharge and charge capacities of the tin thin film electrode were determined to be 709 and 561 mAh(.)g(-1), respectively. Cyclic voltammetric results illustrated that multi-phase changes occurred during the lithiation and delithiation. Electrochemical impedance spectroscopy (EIS) results indicated that SEI film was begun to form on the surface of tin thin film electrode at 1.2 V, and then break down below 0.4 V because of large volume expansion. SEM investigations revealed that the tin thin film electrode appeared serious cracks after 30 charging and discharging cycles.