Hybrid Screen Printable Electrolyte for Large-Scale Flexible Electrochromic Display Production

This study presents the development of a novel screen printable quasi-solid polymer electrolyte (p-QSPE) for Electrochromic Displays (ECDs) applications. p-QSPE is composed of three key components: polyvinylidene fluoride (PVDF), a high-dielectric constant polymer that ensures high ionic conductivity in solid-state; glyceril propoxy triacrylate (GPTA), a UV-cross-linkable monomer that provides structure and durability for overprinting; titanium dioxide (TiO₂) nanoparticles, which modulate the electrolyte's rheological properties for screen printing; reducing the solvent (PC:EC) content to only 35.90 wt.%. Electrochemical Impedance Spectroscopy (EIS) revealed that this well-designed formulation achieved an ionic conductivity of 1.17 × 10⁻³ S cm⁻¹ at room temperature, surpassing the threshold required for commercial applications. Moreover, p-QSPE facilitated the production of fully screen printed ECDs in an industrial printing line, streamlining their production process and achieving an optimal balance between printability, overprint resilience, and device performance. Operational tests for the ECDs showed fast switching times (<6 s for t₉₀ and <2 s for t₇₅) across a wide temperature range (−20 °C to 80 °C). Additionally, the electrolyte demonstrated low charge consumption (2.10 ± 0.11 mC cm⁻²) and a lifespan exceeding 10 000 cycles. These results highlight the potential of p-QSPE as a screen printable, high-performance electrolyte, capable of advancing ECD manufacturing by enabling the production of fully screen-printed, performing ECDs.