Lithium Diffusion into Nb₂O₅ and Nb₂O₅:Li⁺ Thin Films Prepared by Sol Gel Method

Abstract

Aiming to study the solid-state diffusion of lithium into pure and lithium doped niobium pentoxide (Nb₂O₅) thin sol-gel films were investigated by galvanostatic intermittent titration technique (GITT) and electrochemical impedance spectroscopy (EIS). The obtained values of the diffusion coefficient were 2.5 × 10⁻¹¹ at x = 0.83 and 7.4 × 10⁻¹³ at x = 1.65 for pure and doped Nb₂O₅ films respectively. The impedance results of both kinds of films adjusted by equivalent circuits showed very good agreement between experimental and theoretical data.

Keywords:

• electrochromism
• lithium intercalation
• Nb₂O₅
• sol-gel

Acknowledgments

The authors are indebt to FAPESP and CNPq for the financial support given.