Long-term stable quasi-solid-state complementary WO3–NiO electrochromic devices with ultra-fast response

With the rapid advancement of electrochromic technology, providing quasi-solid-state electrolytes that offer superior performance and lower costs holds significant promise for practical applications of electrochromic devices. Herein, a strategy of employing a facile fabrication method for quasi-solid electrolyte and quasi-solid-state electrochromic devices by in-situ UV curing, aims to enhance interfacial interactions, thereby accelerating response time and improving cycling stability. After 120 s of UV polymerization, the electrolyte with PEO accounting for 40 wt% of PEGDA and PEO mixture exhibited excellent conductivity (2.04 × 10 −3  S cm −1 ), thermal stability, optical transmittance (＞85 % @633 nm) and interface bonding strength (0.11 Mpa). These remarkable characteristics lay the foundation for fabricating a quasi-solid-state WO 3 –NiO ECD with an ultra-fast response time of 0.96 s/3.48 s and excellent long-term cycling stability of more than 20000 cycles. This outcome introduces a novel approach to fabricating high-performance electrochromic devices, significantly enhancing their potential applications across various fields.