Characterization of electrolytic tin dioxide deposition on Pt for lithium ion battery applications

By using cathodic electrodeposition, three structures of Sn, Sn6O4(OH)4 and SnO2 could be obtained in the 1 mM SnCl2 aqueous solution for various aeration periods in air. In order to obtain the pure SnO2 coatings as the anode of thin-film lithium ion battery, the aeration should proceed for 10 days to oxidize tin valence from stannous to stannic in SnCl2 aqueous solution. The coating films were further annealed and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR), thermogravimetric–differential analysis (TGA), Raman spectroscopy, and cyclic voltammetry (CV). The as-coating SnO2 film containing 2.4 H2O in the pristine state could be dehydrated at 300 °C for 2 h, or at 250 °C for 12 h. The crystallinity and surface coarsening of the coating films were promoted with increasing annealing temperature. The dehydrated SnO2 film used as the anode of a lithium battery showed a reversible capacity as high as 500 mA h/g after 10 cycles at a discharging rate of 0.2 C, which could result from the nano-sized microstructure of coating film.