A defect-engineering framework for scalable aqueous fabrication of solid oxide cells

Aqueous tape casting offers a sustainable alternative to conventional organic-based processing for solid oxide cells (SOCs); however, large-area manufacturing remains challenging because defects can originate from coupled colloidal, interfacial, and densification mechanisms across successive processing stages. In this work, an integrated defect-engineering framework is developed for the aqueous-fabricated SOCs by systematically linking slurry formulation, lamination behavior, and co-sintering compatibility to the resulting structural integrity. Particle size analysis, rheology, thermogravimetric analysis, optical dilatometry, and electron scanning microscopy were employed to investigate the dominant defects associated with particle agglomeration, air entrapment, interfacial delamination, and shrinkage mismatch. The optimized aqueous processing route enables homogeneous particle packing, effective foam suppression, robust interfacial adhesion, and compatible shrinkage across the multilayer architecture. As a result, SOCs measuring 13 × 13 cm 2 were successfully fabricated by aqueous tape casting, with no cracking or delamination observed by cross-sectional SEM analysis. Electrochemical performance validation carried out with a 5.3 × 5.3 cm 2 cell showed open-circuit voltages within 14 mV of theoretical values, confirming electrolyte gas-tightness, and a maximum current density of 0.5 A cm −2 at thermoneutral voltage under 800 ᵒC. This work establishes a mechanistically informed pathway for the sustainable manufacturing of high-quality SOCs via aqueous processing.