Author: Please check funding information and confirm its correctness.A strong and highly transparent ionogel electrolyte enabled by in-situ polymerization-induced microphase separation for high-performance electrochromic devices.

Electrochromic devices built with ionogel electrolytes are seen as a pivotal step towards the future of quasi-solid electrochromic devices, due to their striking properties like exceptional safety and high ionic conductivity. Yet, the poor mechanical strength of electrolyte of these devices remains a constraint that hampers their advancement. As a resolution, this research explores the use of a robust, transparent ionogel electrolyte, which is designed using an in-situ microphase separation strategy. The ionogels are highly transparent and robust and exhibit excellent physicochemical stability, including a wide electrochemical window and high temperature tolerance. Benefitting from these properties, a high-performance electrochromic device is fabricated through in-situ polymerization with the ionogels, PPRODOT as the electrochromic layer, and PEDOT: PSS as the ion storage layer, achieving high transmittance contrast (43.1%), fast response (1/1.7 s), high coloring efficiency (1296.4 cm 2 C -1 ) and excellent cycling endurance (>99.9% retention after 2000 cycles). In addition, using ITO-poly(ethylene terephthalate) as flexible substrates, a deformable ECD displaying high stability is realized, highlighting the potential use in functional wearables. This article is protected by copyright. All rights reserved.