Facile, low-cost and scalable preparation of V2O5/PEDOT:PSS inks for solution-processed multicolor electrochromic films

Abstract

Poly(3,4-ethylenedioxythiophene) doped with poly(styrene sulfonic acid) (PEDOT:PSS) is extensively used as a commercial ink for electrochromic coatings. However, PEDOT:PSS film has the defect of a single color change, which limits the wide range of applications. The development of hybrid electrochromic inks containing PEDOT:PSS has attracted considerable attention attributed to their high electrical conductivity, large optical modulation, excellent cycling stability and multicolor variation. In this work, the color range of electrochromic PEDOT:PSS ink was adjusted by a simple and low-cost solution blending process method. The solution-processable multicolor vanadium pentoxide (V2O5) nanoribbons synthesized by a facile solution treatment process were used as additives to enlarge the color range of PEDOT:PSS ink. The electrochromic performance of V2O5-PEDOT:PSS hybrid films with V2O5 nanoribbon inclusions ranging from 0 wt% to 100 wt% was systematically studied. Our results demonstrate that the V2O5/PEDOT:PSS hybrid film can combine the color range of mixing inorganic and organic electrochromic materials. The spray-coated hybrid film with 40 % V2O5 nanoribbon (40VPE) shows a reversible multicolor change ranging from navy blue, yellow-green, orange, grey to blue. Moreover, the 40VPE hybrid film also exhibits high optical contrast (50.2 % at 660 nm), rapid response speed (2.7/3.8 s) and excellent cycling stability (sustaining 97 % of initial contrast after 100 cycles). The solution-processable and large-scale V2O5-PEDOT:PSS hybrid inks exhibit promising applications in multicolor electrochromic devices.