Electrochimica Acta, Vol.46, No.22, 3415-3419, 2001
Influence of microstructure on the chemical diffusion of lithium ions in amorphous lithiated tungsten oxide films
We describe how the chemical diffusion of lithium ions is affected by microstructural changes in amorphous lithiated tungsten oxide (a-LixWO3) films as a function of lithium ion concentration. The chemical diffusion of lithium ions in a-LixWO3 films is investigated using ac impedance spectroscopy and Raman scattering measurements. Two different a-WO3 films deposited by thermal evaporation at different partial pressures of nitrogen are used for these measurements. Based on the results of ac impedance spectroscopy and Raman scattering measurements, we conclude that the mechanism of these diffusion phenomena is attributed to an increase or decrease of the W-6 + =O/O-W6+ -O ratio with lithium ion insertion.