Electrochemical lithium insertion in sol-gel deposited LiNbO3 films

Abstract

Inorganic LiNbO 3 ion conducting films were prepared by sol-gel process involving two alkoxides, lithium ethoxide and niobium ethoxide. The films were analyzed by ellipsometry, X-ray diffractometry, scanning electron microscopy and impedance spectroscopy. Impedance spectroscopy indicated that the Li ÷ conductivity values were in the range of 6-8 × 10 -7 S cm -1. The morphology and thickness of these films played an important role in the insertion of lithium ions. Spectrophotometric investigation showed that LiNbO 3 films exhibit very weak cathodic coloration from 350 to 900 nm spectral region. The electrochemical and optical properties clearly indicate that sol-gel deposited LiNbO 3 films can be used as lithium ion conducting layers for electrochromic device application.