For high-performance thin-film solid oxide cells (TF-SOCs), a nanostructured anode functional layer (n-AFL) that can prolong the triple-phase boundary (TPB) is crucial, particularly for low-temperature operation. However, the implementation of n-AFL (usually >1 µm in thickness) has critical issues in scale-up and productivity. Here, the study successfully demonstrates a large-area, high-performance TF-SOFC with an n-AFL fabricated via mass-production-compatible reactive magnetron sputtering. The cell with optimized n-AFL by adjusting crucial reactive-sputtering process parameters, i.e., oxygen partial pressure and sputtering power, shows superior performance compared to that of the cell without n-AFL: the reduction both in ohmic and anodic polarization resistances by 63% and 34%, respectively, and the improvement in maximum power density by 89% (0.705 W cm^-2 vs 1.333 W cm^-2) at 650 °C. When employed in large-scale cell (4 × 4 cm²), the TF-SOFC with n-AFL showed 19.4 W at 650 °C.

This study focused on addressing the challenges associated with the incompatibility between sulfide solid electrolytes and Ni-rich cathode active materials (CAMs) in all-solid-state lithium-ion batteries. To resolve these issues, protective layers have been explored for Ni-rich materials. Lithium lanthanum titanate (LLTO), a perovskite-type material, is recognized for its excellent chemical stability and ionic conductivity, which render it a potential protective layer in CAMs. However, traditional methods of achieving the perovskite structure involve temperatures exceeding 700 °C, resulting in challenges such as LLTO agglomeration, secondary phase formation between LLTO and CAM, and cation mixing within the CAM. In this study, a rapid technique known as flash-light sintering (FLS) was employed to fabricate a uniform and pure perovskite protective layer without inducing cation mixing within the CAM. The LLTO-coated LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) with FLS treatment demonstrated minimal cation mixing and formed a fully covered dense layer. This resulted in a high initial capacity and effectively addressed the incompatibility issues between the sulfide electrolytes and CAM. The rapid FLS method not only streamlines the fabrication of LLTO-coated NCM811 but also provides opportunities for its broader application to materials that were previously deemed impractical because of high sintering temperatures.