ELECTROCHROMIC BEHAVIOR OF A LAMBDA-MNO2 ELECTRODE ACCOMPANYING LI-INSERTION IN AN AQUEOUS-PHASE()

Electrochromism of spinel-type manganese oxide accompanying an Li+-ins ertion in an aqueous phase was examined ted by visual light spectromet ry. An absorbance spectrum for lithiated manganese oxide gave lower ab sorbance in the wavelength range <700 nm than did an Li+-extracted one . The greatest difference was observed at similar to 450 nm and is exp lained by the difference between the spectra for Mn3+ and Mn4+. A reve rsible change in absorbance at 450 nm occurred with the Li+-insertion/ extraction reaction. Cyclic voltammetry indicated that the absorbance change couples with the electrochemical response of the manganese oxid e to Li+ ions.