Development and optimisation of 3D-printed monolithic anode-electrolyte assemblies for high-performance SOFCs

Multi-material digital light processing (DLP) was employed to fabricate monolithic NiO–8YSZ/8YSZ half-cells incorporating an architected gyroid anode and a dense electrolyte. Co-sintering behaviour was optimised to achieve near-full densification of the electrolyte (∼98% relative density at 1350°C) while preserving the designed gyroid porosity of the anode (bulk porosity ∼76%) without interfacial delamination. To enhance electronic connectivity within the porous scaffold, systematic Ni precursor infiltration was performed using 1 and 3 mol L -1 solutions. Incremental mass gain measurements and conductivity analysis revealed capillary-limited saturation behaviour and the establishment of continuous Ni percolation networks after sufficient infiltration. Gradual loading using 20 cycles of a 1 mol L -1 solution produced slightly higher post-reduction conductivity than 10 cycles at 3 mol L -1 , indicating improved spatial distribution of the Ni phase. Single cells fabricated under optimised conditions achieved peak power densities of 497 mW·cm⁻² at 800°C under dry H₂. The results demonstrate that combining architected gyroid design with controlled infiltration enables independent tuning of macro- and microstructural features, providing an effective strategy for enhancing the performance of additively manufactured solid oxide fuel cells.