An all-plastic WO3·H2O/polyaniline electrochromic device

We report on the implementation of the plastic battery technology to the elaboration of a flexible electrochromic device. More specifically, we studied a system constituted of WO3·H2O monohydrate tungsten oxide switching against polyaniline (PANI) conducting polymer. We first describe the electrochemical and optical properties of each cell component within a non-aqueous organic 1-M LiPF6 EC/DMC liquid electrolyte. Then PVDF-HFP polymer-based stacks, constituted of each plastic electrode separated by a plastic membrane, were built by: (i) holding the layers together by capillarity, and (ii) by hot-lamination of all layers to a single one. Both devices were investigated for their optical performances. Despite a loss of transmission level, the optical contrast turned out to be higher for the hot-laminated configuration. However, for reasons that will be developed, the electrochromic efficiency was well below the one expected from solid-state windows.