This study presents a performance evaluation platform for sputtered thin-film electrodes used in biogas-driven, low-temperature solid oxide fuel cells (SOFCs). The design considerations include electrolyte material composition and thickness, anode material composition and thickness, anode fuel composition, and cathode composition and thickness, all derived from a review of existing literature. For the electrolyte, we propose a thickness of 100 μm for the main electrolyte made of gadolinium-doped ceria (GDC) and 0.1 μm for the auxiliary electrolyte made of scandia-stabilized zirconia. In terms of anode fabrication, we suggest a material composition of Ru/Ni-Cu-GDC, with thicknesses of 1 μm for Ni-Cu-GDC and a few nanometers for Ru in the nanoporous anode. For the anode fuel supply, we recommend mole ratios of 45% to 75% CH₄ and 25% to 55% CO₂ to assess the impact of biogas composition on power performance. Lastly, for the cathode, we propose a material composition of Pt-Ti-samarium-doped ceria with a thickness of 100 nm for the nanoporous structure.

A yttria-stabilized zirconia (YSZ) cathode functional layer (CFL) was fabricated using a co-sputtering process to improve the oxygen reduction reaction (ORR) in solid oxide fuel cells (SOFCs). To optimize the yttria molar percentage and achieve a nano-granular structure with enhanced grain boundary density, the DC sputtering power for the metallic yttrium target was varied at 10, 30, and 50 W. Structural and compositional analyses were performed using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and X-ray diffraction (XRD). The results indicated that a DC power of 30 W resulted in a well-developed grain structure with high grain boundary density and an yttria composition close to the optimal molar percentage of 8-10 mol %. Under these optimized conditions, the SOFC with the co-sputtered YSZ CFL achieved a maximum power output of 9.22 mW/cm² at 450^oC, representing approximately a 43% enhancement compared to the reference cell. This highlights the significant potential of co-sputtering for future low-temperature SOFC applications.

In this study, Yttria-stabilized zirconia (YSZ) functional layers were applied with different thin-film fabrication process such as sputtering and atomic layer deposition (ALD) to enhance oxygen reduction reaction (ORR) for solid oxide fuel cells. We confirmed that the YSZ functional layer deposited with sputtering showed relatively low grain boundary density, while the YSZ functional layer deposited with the ALD technique clearly indicated high grain boundary density through scanning electron microscopy (SEM) and X-ray diffractometry (XRD) results. The YSZ functional layer coated with the ALD technique revealed that more ORR kinetics can occur using high grain boundary density than the functional layer deposited with sputtering. The peak power density of the SOFC deposited with ALD YSZ indicates 2-folds enhancement than the pristine SOFC.

Nature-inspired architected materials have been widely used to achieve efficient structural materials by harnessing their cellular and hierarchical structures. For example, biological materials observed in bone, shell, nacre, and wood contain constituents, ranging from nanometers to centimeters, arranged in an ordered hierarchy. Because of their composited structures that contain micro and nanoscale building blocks arranged in an ordered hierarchy and the material size effect in the mechanical strength of nano-sized solids, bioceramic materials are mechanically robust and lightweight. The design principles offered by hard biological materials of multiscale composite structures can assist in the creation of advanced ceramic architectures. In addition, the evolution of additive manufacturing technologies has enabled the fabrication of materials with intricate cellular architected materials. In this review, we discussed advanced additive manufacturing for the fabrication of nature-inspired multiscale ceramic structures by combining conformal thin-film coating technique with conventional additive manufacturing methods.

Picosecond ultrasonic evaluation on the Young’s modulus of a ceramic thin-film was performed in the present study. A 100nm thick silicon nitride thin-film was deposited on a silicon wafer using the plasma enhanced chemical vapor deposition technique and gigahertz-frequency longitudinal bulk waves were excited in the film using a femtosecond laser setup. A thermoelastic equation was numerically solved using the finite difference method and compared to the experimental data to estimate the elastic property of the film. Results show that the present measurement technique can effectively evaluate the film’s Young’s modulus and it is recognized that the modulus is 60-70% lower than that of its bulk status. This study is expected to provide a way to characterize nanoscale ceramics with very high spatial and temporal resolutions for the design and analysis of microelectromechanical systems and thin-film based devices.

The energy saving effect of reactant plasma in Atomic Layer Deposition (ALD) of ultrathin solid oxide fuel cell electrolyte was examined by measuring electrical current in real time. Actuating a plasma generator led to a remarkable change in electric current and therefore a Plasma Enhanced ALD (PE-ALD) Yttria-Stabilized Zirconia (YSZ) supercycle demanded ~12% higher process energy than a Thermal ALD (T-ALD) YSZ supercycle. Nonetheless, because PE-ALD YSZ electrolyte providing higher growth rate and higher gas tightness needed 2 times smaller cycle number compared to T-ALD YSZ electrolyte, applying oxygen plasma in ALD of YSZ electrolyte resultantly reduced total process energy by ~44%.