Realisation of solid-state electrochromic devices based on gel electrolyte

Background: Since the last decade, there has been much interest in solid polymer electrolyte (SPE) to address the issues of electrolyte leakage and evaporation in electrochromic devices (ECD). ECD is a state-of-the-art technology having the ability to change from transparent state to opaque state under the influence of a small applied voltage for energy saving applications.
Methods: In this work, tungsten oxide (WO3) films were fabricated via the sol-gel spin-coating method. Subsequently, ECDs were assembled based on SPE and liquid polymer electrolyte (LPE) respectively, using indium doped tin oxide (ITO) coated glass as conducting electrodes and WO3 films as working electrode.
Results: Cyclic voltammetry (CV) results revealed reduced ionic conductivity of conducting ions in SPE based ECD (SECD) owing to increased viscosity by addition of PMMA. However, lesser time was required for the colouration process. LPE based ECD (LECD) showed higher colouration efficiency (CE) compared to its SE...