An electrochromic window assembly in the opaque state. Both the tungsten oxide (WO3) and nickel oxide (NiO) are opaque. The current of negative electrons towards the NiO electrode is balanced by the migration of Li+ ions towards the NiO electrode. 과학 엔지니어링 일렉트 로크로 믹 일렉트 로크로 믹 창-불투명