Preparation of a Star Network PEG‐based Gel Polymer Electrolyte and Its Application to Electrochromic Devices

Abstract

Abstract A star network polymer with a pentaerythritol core linking four PEG‐block polymeric arms was synthesized, and its corresponding gel polymer electrolyte based on lithium perchlorate and plasticizers EC/PC with the character being colorless and highly transparent has been also prepared. The polymer host was characterized and confirmed to be of a star network and an amorphous structure by FTIR, 1 H NMR and XRD studies. The polymer host hold good mechanical properties for pentaerythritol cross‐linking. Maximum ionic conductivity of the prepared polymer electrolyte has reached 8.83×10 −4 S·cm −1 at room temperature. Thermogravimetry (TG) of the polymer electrolyte showed that the thermal stability was up to at least 150 °C. The gel polymer electrolyte was further evaluated in electrochromic devices fabricated by transparent PET‐ITO and electrochromically active viologen derivative films, and its excellent performance promised the usage of the gel polymer electrolyte as ionic conductor material in electrochromic devices.