Controlled UV-curing-assisted fabrication of ultrathin YSZ electrolyte membranes for solid oxide fuel cells

Ultrathin yttria-stabilized zirconia (YSZ) electrolytes can reduce ohmic losses and improve solid oxide fuel cell (SOFC) efficiency, yet fabricating dense, gas-tight micrometer-scale membranes on porous supports remains challenging. Herein, a UV-curing-assisted dip-coating strategy is developed for the controllable fabrication of ultrathin YSZ membranes. Rational regulation of slurry wettability and rheology mitigates capillary-driven infiltration into the porous support, whereas UV-triggered cross-linking offers transient structural stabilization to preserve membrane integrity throughout the drying process. Based on thermal decomposition analysis, a stress-managed sintering process is established to obtain dense and defect-free YSZ electrolyte membranes with a thickness of ∼2 μm. The optimized single cell delivers a peak power density of 750 mW cm −2 at 800 °C and over 140 mW cm −2 at 650 °C, respectively, together with excellent operational and thermal cycling stability. These results demonstrate great potential of UV-curing-assisted dip coating strategy for fabricating ultrathin electrolyte membranes for high-efficiency SOFCs.