Controlled assembly and synthesis of oxygen-deficient W18O49 films based on solvent molecular strategy for electrochromic energy storage smart windows.

W 18 O 49 -PB device can realize different optical modulation modes at different voltages. [Display omitted] • A simple solvent molecular strategy is proposed to control the morphology and crystallinity of W 18 O 49. • The morphology of W 18 O 49 film changes from the porous nanowire network of methanol to the nanowire array of n-propanol. • The porous reticulate W 18 O 49 film synthesized in methanol shows excellent electrochromic properties. • W 18 O 49 film synthesized in methanol exhibits high energy storage to improve energy utilization. 18 O 49 is a promising electrochromic material with abundant oxygen vacancy and high carrier mobility. However, the electrochromism of W 18 O 49 is not satisfactory, the regulation and synthesis of high-performance W 18 O 49 have become the research hotspot. In this work, it is found that the main chain and side chain structure of solvent molecules can control the assembly and synthesis of W 18 O 49 film, so as to achieve excellent electrochemical and electrochromic properties. The porous reticular W 18 O 49 film synthesized in short-chain molecular solvent shows the excellent transmittance modulation (81.6 % at 633 nm, 77.0 % at 1050 nm), and exhibits the high energy storage of 41.7 mF cm−2 at 0.1 mA cm−2. Solvent molecular strategy provides a new way for the synthesis and regulation of W 18 O 49 electrochromic films and promotes the further development of high-performance electrochromic materials. [ABSTRACT FROM AUTHOR]