JPS56138722A - Electrochromic element - Google Patents

Abstract

PURPOSE:To make stable operation during long-term current conduction and under application of high voltage by providing the 3rd electrode consisting essentially of graphite other than the display electrodes and counter electrode of an electrochromic (EC) element and applying voltage across said electrode and the counter electrode. CONSTITUTION:A transparent electrode 2 and an EC material (amorphous WO3, etc.) 3 are formed on the transparent substrate 1 of the EC element. On the other hand, an electrode 5 and the same EC material 6 as that mentioned above on the electrode 5 are formed on a substrate 4 to make a counter electrode. A conductive layer 11 is formd on the substrate 4 of said element by using a metallic or conductive film (In2O3) and the graphite made into paste by mixing with an inert fluorine contd. resin etc. in electrolyte 8 or the like is coated on the layer 11 and is heat- treated, whereby a graphite electrode 12 is provided. With the counter electrode 5 made negative, voltage is applied across the same and the electrode 12 so that the EC material 6 on the electrode 5 is kept colored. Thereby, the driving of the EC element is accomplished under low voltage, and there is no elution of harmful ions from the electrode 12 to the electrolyte 8, whereby the element is made longer in life.