Preparation and characterization of PEO based organic-inorganic hybrid gel polymers for electrochromic devices

In this paper, 3-glycidyl ether oxypropyltrimethoxysilane (KH560) was incorporated into the reaction product of polyether amine (2-APPG) and polyethylene glycol diglycidyl ether (PEDGE) to create an organic-inorganic hybrid polymer. The hybrid polymer underwent the catalytic hydrolysis of a hydrochloric acid-ethanol solution and was then swelled in the liquid electrolyte containing lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) to form the novel hybrid polymer electrolyte (GPE). The TGA results indicate that the samples underwent a 4% mass loss within the temperature range of 25 °C to 280 °C. The electrochemical test results show that the conductivity of the GPE reaches 1.57 × 10⁻³ S/cm at room temperature, and the lithium-ion transference number (t⁺) reaches 0.22. In addition, electrochromic devices prepared with APK-1 as the electrolyte exhibit good light density change (∆ (OD) = 0.134), coloring efficiency of 153.3 cm²/C, and stability with 400 stable cycles within the voltage range of -2.5 V to 2.5 V. The above tests demonstrate the enormous potential of the proposed GPEs in the application of electrochromic devices.