An electrochromic display having enlarged surface area of the electrochromic material for rapid coloration and rapid bleaching yet fabricated so as to prevent corrosion of the electrode by the electrolyte. In a first embodiment, the display includes a conductive electrode formed on a substrate; a protective layer formed on the conductive electrode; a porous layer of an electrochromic material formed on the protective layer; a counter electrode formed apart from the porous layer; and an electrolyte disposed between the porous layer and the counter electrode. The protective layer is fabricated from a dense layer of an electrochromic material and the conductive electrode is fabricated from a metal non-reactive with the electrolyte. The porous layer is in direct contact with the conductive electrode. In a second embodiment, the electrode is made from a conductive material that is non-reactive with the electrolyte.

A thin electrochromic display suitable for manufacture in a continuous process on a backing tape which becomes part of the display. The display is a sandwich structure comprised of a transparent substrate, transparent electrodes having persistent electrochromic material thereon, a solid cationic ion exchange resin electrolyte in contact with the electrochromic material, a conductive metal foil member with electroreactive layer thereon, and an impervious adhesive backing tape adhered to the substrate around the foil member and also covering and adhered to the foil member to seal the display and having an aperture therein for permitting electrical contact to be made with the foil member.

An electrochromic layer-set, operating with hydrogen, comprises a transparent substrate front face plate, at least two electrodes, at least one electrochromic layer, a hydrogen ion-storing layer, a hydrogen ion-conducting layer, a rear face in sealing relationship with the layer-set, directly following one of the two electrodes, there being a metallic layer between the rear face and the layer lying in front of the rear face (the electrode) or the rear face itself is formed by this metallic layer. The side of the metallic layer turned away from the substrate plate is optionally transformed into the oxide of the metal. For the application of such a metallic layer, the layer-set and a counter-electrode are immersed in an electrolyte containing the metal ions, with the electrode lying at the rear face of the layer-set being made the negative electrode.

Electrochromic display devices which will maintain coloration after the electric current has been removed will comprise an electronic conductor consisting of a support which may be electrically conductive per se or contain an electronic conductor thereon, an electrochromic material in contact with said conductor, a solid electrolyte comprising a blend of an organic polymer and a heteropoly acid or salt thereof disposed on said electrochromic material and a counter-electrode in contact with the solid electrolyte. By utilizing this type of solid electrolyte, it is possible to obtain a display device which may range from about 5 to about 100 microns in thickness.

An electrochromic article comprising plastic substrates and a method for constructing such an article are disclosed wherein two plastic substrates are coated with a primer to adhere an electroconductive metal oxide film, onto which are deposited an electrochromic film and a complementary film respectively. The two coated plastic substrates are assembled to form a cavity into which is placed a solution of monomers which are polymerized to form an ion-conducting copolymer.