An All-in-One Electrochromic Device Containing Thermally Cured Dual Functional Viologen

Abstract

Viologens are promising electrochromic material due to their high optical contrast when switched between its oxidized/reduced states.1,2 However, the utilization of the viologen in liquid form would lead to leakage problems.3Herein, a thermal-cured electrochromic gel was prepared through the utilization of dual functional vinyl-bearing viologen, which acts as an electrochromic chromophore and at the same time serves as a thermal cross-linker. When this dual functional viologen was injected into an electrochromic device (ECD), followed by the thermal treatment, an uniform electrochromic gel can be obtained. This approach provides an easier fabrication of the all-in-one leakage-free ECD. Moreover, this leakage-free ECD exhibits good compatibility with electrolytes and other chromophores, thus resulting in uniform color change. Significant optical contrast can be achieved in this ECD (as shown in Fig. 1(a)). Ultimately, This ECD reveals reversible coloring and bleaching processes while maintaining high transmittance change (> 55%) at 615 and 570 nm (as shown in Fig 1(b) and Fig. 1(c)). REFERENCES (1) Mortimer, R. J. Chem. Soc. Rev.1997, 26, 147. (2) Mortimer, R. J.; Varley, T. S. Chem. Mat.2011, 23, 4077. (3) Thakur, V. K.; Ding, G. Q.; Ma, J.; Lee, P. S.; Lu, X. H. Adv. Mater. 2012, 24, 4071. Figure 1