Self-supporting, ultra-thin and highly transparent conducting nickel grids for extremely flexible and stretchable electrochromic devices

It has been a great challenge to design an extremely flexible and stretchable electrochromic device (ECD), due to the physical deformation and fracture of the conductive materials and supporting substrates after plenty of bending. To solve the aforementioned shortcoming of ECDs, in this paper, a self-supporting metal Ni gird electrode is mentioned, which discarded solid or flexible polymeric substrates, having outstanding features of extremely foldability (bending radius lower 50 mu m), stretchability (stretching to 117.6%), excellent conductivity (sheet resistance lower 0.4 Omega/sq), high transmittance (about 90% in full spectra), and ultra-thin thickness (3.7 mu m). By assembling the metal electrode, the electrochromic material and the hydrogel, a paper-thin, ultra-flexible, and stretchable ECD with an overall thickness of 113 mu m was prepared, which could be attached to the manifold and undulating surface of things and be stretched without compromising the dynamic bleaching and coloration performance. The triple-layered and substrate-free ECD with excellent flexibility and wearability could serve as futuristic electronics used for multiple purposes, like flexible displays, camouflage wearables and medical monitoring, etc. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

This study introduces a self-supporting metal Ni grid electrode for an electrochromic device, which possesses exceptional flexibility, stretchability, conductivity, and transmittance, producing a paper-thin, ultra-flexible, and stretchable ECD. This substrate-free ECD, with three layers, shows promise for future applications in flexible displays, camouflage wearables, medical monitoring, and more.