TiO₂-Driven Enhancement of Electrochromic Performance of Polymer Electrolytes: Insights and Mechanisms

Abstract

In recent years, electrochromic laminated glass has been widely used in automobile, and building depending on its comfort and energy efficiency, however, its promotion are limited due to its complex structure. Herein, TiO₂ enhanced conductive polyvinyl butyral (PVB) film has been constructed by blending process. Its ionic conductivity can reach as high as 9.6×10-4 S/cm, which is attributed to the more lithium ion transport channel in the composite film. In another, a 10◊10 cm2 of the corresponding electrochromic devices (ECD) with FTO/WO3/PVB/NiO/FTO structure was assembled by hot press process, and the enhancement in electrochromic performance was systematically evaluated. The tensile strength reaches 34.6 MPa, with the elongation at break reached 141%, and the adhesive strength is 5.5 MPa, which is equivalent to the automotive grade PVB film. Drop ball tests show that, at a 190 cm drop height with a 30 g mass, the device loses only 1.2% of its mass, which can be confirmed of its excellent safety. The devices not only exhibited a fast response time of 4 s at a low voltage of ±3 V, but also demonstrated excellent electrochemical stability and cycling reversibility over 10,000 CV cycles. This work clarifies the coupling relationship between ion transport and device color change, demonstrating potential application value in ECDs. Subsequent research can further integrate interfacial engineering strategies to advance the integration and application of CPE in practical devices.