Optimization Study of Solid‐State Electrochromic Devices Based on WO 3 / Lithium ‐ Polymer Electrolyte / V 2 O 5 Structures

Transmissive solid-state electrochromic devices based on the structure of WO[sub 3]/lithium-polymer electrolyte/V[sub 2]O[sub 5] were optimized for potential large-area window applications. The electrochromic layer thicknesses, polymer molecular weights, lithium-containing electrolytes, preassembly lithium-ion injection amounts, and transparent conductor substrates were systematically investigated for large optical modulation and fast response of the devices. The transmittance of the optimized device at 633 nm can be switched between 74 and 12% in 1 min. The coloring and bleaching voltages were [minus]1.8 and 1.2 V, respectively.