THIN-LAYER TYPE ELECTROCHEMISTRY AND STABILITY STUDIES OF PRUSSIAN BLUE FILMS IN NONAQUEOUS ELECTROLYTES

In marked contrast to behavior in aqueous systems, linear dependence of peak current over a wide range of scan speeds is reported for the process (Prussian blue) reversible (Everitt's salt) in CH3CN and DMF with Na+ and Li+ supporting electrolytes. Such thin layer behavior suggests that, by moving to CH3CN (or DMF) from water, kinetic control no longer lies in the diffusion of cations in and out of the film, but rather in processes taking place within the film. Prussian blue films on Pt are very stable upon electrochemical cycling in these non-aqueous media, and can be used in fast electrochromic devices.