Roughness Effect on the Lithium Diffusivity in WO3 Thin Films

Abstract

AbstractIn this work, we investigate the influence of surface roughness on the kinetics of Li+ during the insertion process in the well-known electrochromic material WO3. Thin films 500 Å thick have been grown by rf-sputtering and annealed in therange of 25-350ºC. Grazing angle X-ray reflectometry shows that the film roughnessincreases considerably with thermal treatment. These measurements are correlated with chemical diffusion investigations obtained by electrochemical titration in Li/WO3 cells.