Figure 7: Schematic diagram of (a) porous WO3 EC glass structure that can be simulated by using resister, capacitor, and Warburg impedance. Each interface of ITO/WO3, WO3/electrolyte, electrolyte/NiO, and NiO/ITO can be simulated using a RC parallel circuit, and bulk material such as ITO and conducting wire can be simulated by a series of resistors. (b) and (c) Equivalent circuit used for modeling the EIS of EC glass. The impedance of the bulk matter is simulated by , the impedance of working electrode is simulated by ( // +( // )), the electrolyte is simulated by //( ), and the counter electrode is simulated by ( // ) +( // ).