PREPARATION METHOD OF ACTIVATED METAL OXIDE

摘要

A method for activating metal oxides used as an electrochromic material, which can improve performance of an electrochromic device and can secure economic efficiency of the electrochromic device by using a counter electrode with a high electric capacity and/or increasing an application voltage required in oxidation-reduction reaction of the metal oxides, is provided. A preparation method of activated metal oxide comprises: a first step of forming a metal oxide on a conductive substrate to provide a metal oxide electrode; and a second step of performing oxidation-reduction reaction one or more times by using a counter electrode having three times or more of an electric capacity than that of the metal oxide formed in the first step, and applying an oxidation-reduction voltage to the metal oxide electrode within an electrolyte containing an alkali metal salt. The metal oxide is oxides of one or more metals selected from the group consisting of transition metals, metals belonging to group 13 or group 14, and rare earth elements. The metal oxide can form a metal composite oxide containing an alkali metal by inserting alkali metal ions. The metal oxide has electrochromic properties.