Improving of SOCs performance by 3D printing are proved, increasing the active area by high-aspect ratio structuration of their components.

Diffusion barrier layers are typically introduced in solid oxide fuel cells (SOFCs) to avoid reaction between state-of-the-art cathode and electrolyte materials, La1–x Sr x Co1–y Fe y O3‑δ and yttria-stabilized zirconia (YSZ), respectively. However, commonly used layers of gadolinia-doped ceria (CGO) introduce overpotentials that significantly reduce the cell performance. This performance decrease is mainly due to the low density achievable with traditional deposition techniques, such as screen printing, at acceptable fabrication temperatures. In this work, perfectly dense and reproducible barrier layers for state-of-the-art cells (∼80 cm2) were implemented, for the first time, using large-area pulsed laser deposition (LA-PLD). In order to minimize cation interdiffusion, the low-temperature deposited barrier layers were thermally stabilized in the range between 1100 and 1400 °C. Significant enhanced performance is reported for cells stabilized at 1150 °C showing excellent power densities of 1.25 W·cm–2 at 0.7 V and at a operation temperature of 750 °C. Improved cells were finally included in a stack and operated in realistic conditions for 4500 h revealing low degradation rates (0.5%/1000 h) comparable to reference cells. This approach opens new perspectives in manufacturing highly reproducible and stable barrier layers for a new generation of SOFCs.

Heat treatment of LLZO garnets can effectively remove lithium hydroxide and carbonate layers from its surface, increase the Li dynamics in the structure and improve the processing of composite polymer electrolytes for solid-state batteries.

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Recently, it has been demonstrated that the application of additive manufacturing (AM) technologies for functional ceramics fabrication, especially to SOC production, leads to significant improvement of the process. AM represents freedom of design that allows to enhance the performance of the SOC-based device and to increase manufacturing productiveness, while the waste material is reduced. As a result, a one-step printed monolithic SOFC stack could be produced combining different AM technologies in a single printing process. For this purpose, hybrid 3D printing technology which combines stereolithography and robocasting has been developed. Thus, the technique uses 8YSZ for the electrolyte fabrication by stereolithography and deposition of electrodes and interconnectors by robocasting. The elaborated hybrid multimaterial 3D printing technology renders possible complete SOC stack fabrication as a single-step process. Complete fully printed SOFC cells, their co-sintering process, and their characterization are here presented and discussed.