Improved Dry‐Pressing Strategy for Fabricating Double‐Sided Rough YSZ Electrolyte Thin Films and Their Performance in Solid Oxide Cells

ABSTRACT This study addresses limitations of the conventional dry‐pressing method for electrolyte‐supported films—smooth surfaces, excessive thickness, and fragile supports inducing damage. We propose an innovative camphor–quartz sand composite architecture to construct a five‐layer (camphor/quartz sand/YSZ/quartz sand/camphor) system, enabling thin yttrium‐stabilized zirconia (YSZ) electrolyte films with double‐sided rough surfaces for solid oxide cells (SOCs). Camphor is removed nondestructively via thermal sublimation, while quartz sand tunes surface roughness. The fabricated YSZ‐M films exhibit average roughness (R a ) of 9.89 and 11.54 μm (vs. 0.24 and 0.39 μm for conventional YSZ‐T films) with reduced thickness. At 850°C, YSZ‐M‐supported SOCs show superior performance: In SOFC mode, open‐circuit voltage reaches 1.11 V and peak power density hits 0.58 W·cm −2 with lower ohmic and polarization resistance; in SOEC mode, CO 2 electrolysis current density reaches 1.81 A·cm −2 (vs. 1.19 A·cm −2 for YSZ‐T‐based cells) with lower full‐frequency impedance. This improvement stems from synergistic electrolyte thinning and double‐sided roughening, promoting gas diffusion and ionic transport. Adaptable to multiple electrolytes and low‐cost, this method supports large‐scale electrolyte film production and SOCs commercialization.