HYDRATED MANGANESE OXIDE AS A COUNTERELECTRODE MATERIAL FOR AN ELECTROCHROMIC OPTICAL SWITCHING DEVICE

Thin films of hydrated manganese oxide were electrodeposited out of a base solution onto conductive SnO2: F glass. When cycled in a 1 M KOH solution, these films show the ability to reversibly store ions of dissociated water, however they show phase instability upon longer cycling. X-ray photoelectron spectroscopy was employed to investigate the chemical composition of the manganese oxide films. Our results indicate that hydrated MnO2 is the composition of the film in the oxidized state. Very low coloration was noted in these films making them useful for transparent counter-electrodes. As indicated by voltammetry, the switching voltage and ion-storage capacity fit the electrochromic switching of nickel oxide, undergoing a similar reaction. Because of its properties, manganese oxide, once stabilized, may serve as a counter-electrode for an electrochromic nickel oxide device. © 1990.