Preparation and Properties of Electrochromic .LAMBDA.-MnO2 Thin Film by Dip Coating Method.

Abstract

A new electrochromic material λ-MnO2 thin film was prepared from LiMn2O4 thin film by acid treatment. LiMn2O4 thin film was prepared by dip coating method using manganese acetate tetra-hydrate (Mn(OCOCH3)4⋅4H2O) and lithium acetate di-hydrate (Li(OCOCH3)⋅2H2O) as starting materials, and ethanol (C2H5OH), ethylene glycol monoethyl ether (C2H5OCH2CH2OH), 2, 4-pentanedione (CH3COCH2COCH3) and water as solvents. λ-MnO2 thin film showed electrochromism by application of voltage. The color of thin film changed from reddish brown to transparent.