A lichen-inspired top-blocking/bottom-transport complementary strategy: Constructing stable electrochromic devices by bionic bilayer gel electrolytes via synergistically enhanced Lewis acid-base regulation and interfacial hydrogen bond network

Top-blocking & bottom-transporting electrolytes boost stability and ion transport. • Synergistic interfacial H-bond network and ion exchange for the durability of devices • All-printed electrode-electrolyte system for curved-pattern display in packages. Electrochromic technology holds immense promise for diverse applications, yet electrolytes struggle to reconcile stability with high ionic conductivity, impeding device performance optimization. Inspired by the multilayered structure of lichens, functionally complementary bilayer gel electrolytes are fabricated: the upper hydrophobic PMMA-based ionic liquid gel serves as a robust barrier layer, while the lower hydrophilic PVA-based hydrated gel constructs continuous ionic transport pathways, with interfacial strong adhesion enabled via an intermolecular hydrogen bond network. The Lewis acid-base mechanism modulates the ionic solvation environment through electron pair donation and acceptance, facilitating active ion dissociation and migration. This design yields remarkable device performance enhancements: coloring/bleaching response times shorten to 4.3 s/3.2 s, capacitance retention remains 91.35% after 1000 charge-discharge cycles and 90.15% post 500 bending cycles. The electrolyte exhibits excellent print compatibility, screen-printable on curved substrates; its transparent bilayer (transmittance ≥95%) can be patterned into “SUST” for on-demand information display and concealment, providing a novel technical avenue for electrochromic devices in smart packaging, anti-counterfeiting and beyond. Download: Download high-res image (148KB) Download: Download full-size image