An Organic Aqueous Gel as Electrolyte for Application in Electrochromic Devices Based in Bismuth Electrodeposition

• Published in: Journal of the Electrochemical Society Vol. 150; no. 11; pp. E578 - E582
• Main Authors: de Oliveira, Silvio C., de Morais, Luı́s C., da Silva Curvelo, Antonio Aprigio, Torresi, Roberto M.
• Format: Journal Article
• Language: English
• Published: 01.11.2003
• ISSN: 0013-4651
• DOI: 10.1149/1.1615610

The purpose of this work was to study the deposition/dissolution behavior of bismuth in an aqueous electrolytic gel media from the point of view of electrochromic phenomena. The gel was made from a derivative polymer of animal protein. This polymer is extremely consistent, and it becomes a transparent gel from 350 to 850 nm (visible region). Moreover, voltammetry and chrono-amperometry experiments have shown that the bismuth deposition/dissolution has excellent electrochemical reversibility with a large variation of transmittance values (around 60%) when Cu(2+) is added to the gel. It was also shown that copper cations promote Bi/Bi(3+) reversibility by a redox reaction between Cu(2+) and metallic bismuth. Thermogravimetric (TG) and differential Scanning calorimetry (DSC) analysis were used to verify possible changes in the gel when it was exposed to a heating/cooling cycle. From TG analysis it was possible to verify that degradation of the gel polymer in a large temperature range does not occur and from DSC it was observed that the system only freezes at ca. -35DGC.