Printability of carboxymethyl cellulose/glass-containing inks for robocasting deposition in reversible solid oxide cell applications

Water-based inks containing carboxymethyl cellulose (CMC) and glass particles were investigated in terms of rheological properties and printability for solid oxide cell joining application using robocasting for the first time. The ink formulation containing 36 vol% of glass showed the highest yield stress (9.6 × 102 Pa) and viscosity (4 × 104 Pa.s). CMC-based paste with 37 vol% of glass was selected for printing on Crofer22APU steel substrate due to its relatively low viscosity (2.6 × 104 Pa.s) and high storage modulus (1.4 × 105 Pa), thus ensuring an easier extrusion and shape retention upon printing. The high solid loading of 37 vol% along with optimised debinding and sintering stages enabled achieving high-quality Crofer22APU/glass sealant joining with a reproducible thickness and low porosity.