Conductive adhesive electrode exhibiting superior mechanical and electrical properties for attachable electrochromic devices

Abstract

Here we present the preparation of a conductive adhesive electrode (CAE) for attachable electrochromic devices (ECDs). A photo-curable type of acrylic adhesive film was used as a substrate, and a smooth electrode was obtained with an overcoat of PEDOT:PSS onto pre-formed silver nanowire networks. By examining various compositions, the transmittance and electrical conductivity, with the resulting figure of merit ( F o M ) value, were optimized. The ECDs were fabricated by spray-coating a prepared EC gel layer composed of dihexyl viologen hexafluorophosphate, poly(vinylidene fluoride-co-hexafluoropropylene), and 1-butyl-3-methylimidazolum bis(trifluoromethylsulfonyl)imide. The electrochromic properties of the attachable ECDs were investigated in terms of cyclic voltammetry (CV), spectroelectrochemistry, and kinetic stability. The ECD started coloration at −0.9 V and was completely colored at −1.7 V, with the transmittance difference estimated to be 71.9%. The coloration efficiency was 213.7 cm 2 /C, and the cyclic stability was maintained after 2000 s with a change of less than 5%. Besides, a textile ECD was prepared by attaching an attachable ECD onto cotton fabric, which exhibited a reflectance difference of 17.8% at 604 nm and a color difference of 71.75 in terms of the chromaticity coordinates. These results suggest a promising platform for attachable electrochromic devices capable of exhibiting stable and noticeable color changes on any solid surface. • We obtained a conductive adhesive electrode by coating PEDOT:PSS and silver nanowire on the adhesive film. • The attachable electrochromic device was fabricated by spray-coating a gel layer. • The prepared device exhibited a reversible color switchings. • The textile device was prepared by applying the attachable device on the cotton fabric. • Fabric showed noticeable color changes by electrochemical transitions.