Nanostructured Columnar Tin Oxide Thin Film Electrode for Lithium Ion Batteries

Abstract

Nanostructured tin oxide thin films with columnar grains were deposited on gold-coated silicon substrates using the combustion chemical vapor deposition method. Microscopy revealed that the columnar grains were covered by nanoparticles of less than 20 nm. The electrochemical behavior of the as-prepared thin film electrodes was examined against a lithium counter electrode. These thin film electrodes exhibited high specific capacity and good capacity retention. The capacity increased from an initial value of about 353 (μA h)/(cm2 μm) gradually to a maximum value of ∼490 (μA h)/(cm2 μm) during cycling. The reversible capacity was about 460 (μA h)/(cm2 μm) after 80 cycles at a charge/discharge rate of 0.3 mA/cm2. When the electrodes were discharged at 0.9 mA/cm2, the capacity retention obtained was about 64% of the capacity at 0.3 mA/cm2. The good electrochemical performance is attributed to the unique nanostructure with longitudinal and radial connectivity of active materials.