Towards the scale-up of solid-state, low-emissive electrochromic films, fabricated on a single substrate with novel electrolyte formulations

This experimental work reports the activities of design, fabrication and characterization of an innovative solid-state electrochromic device, deposited on a single substrate with high transparency in the bleached conditions and a wide modulation of transmittance (ΔT of 60% at 750 nm) both in the visible and near-infrared wavelengths. A tailored formulation of the solid electrolytes, based on sulfonated tetrafluoroethylene-based fluoropolymer-copolymer dispersions and the accurate design of a suitable layer of porous tin oxide nanoparticles provided high coloration and bleaching kinetics and recovery of the pristine conditions, even after 500 complete cycles. Devices were scaled-up to 10 × 10 cm2 size, without mechanical and aesthetic defects and relevant homogeneity, throughout the coloration and bleaching processes. Furthermore, this device shows the further feature to be a low-emissivity dynamic solar control film, highly compatible with integration within insulated glazed units.