Nanoscale Interface Engineering of LaCrO ₃ –CeO ₂ Composite Fuel Electrode for High-Performance Multifunctional Solid Oxide Cells

In-situ exsolution technology has been widely investigated in developing perovskite-ceria composite fuel electrodes for solid oxide cells (SOCs) owing to its well-balanced catalytic activity and stability. Among these materials, the synergistic effect between exsolved metal/alloy nanoparticles and the perovskite matrix has been widely explored, while the critical role of the perovskite/ceria interface construction remains largely unexplored. This study breaks ground by developing a nanocomposite LaCrO₃&CeO₂ fuel electrode through a cosynthesis approach, featuring nanoscale alternating distribution of LaCrO₃ and CeO₂, along with Ni nanoparticles in situ exsolved from the LaCrO₃ particle surface as catalytic sites after reduction. The resulting cell, supported by LSGM electrolytes (∼220 μm), exhibits excellent electrochemical performance in various operating conditions. At 800 °C, the peak power density reaches 1.489 W cm^-2 and 1.260 W cm^-2 with H₂ and wet CH₄ as fuels, respectively, and the current density at 1.3 V reaches 1.778 A cm^-2 for H₂O-CO₂ coelectrolysis and 1.445 A cm^-2 for pure CO₂ electrolysis─significantly surpassing the performance of the cell with the conventional mechanically mixed fuel electrode. More importantly, the enhanced synergistic effect achieved through nanointerface engineering effectively inhibits both carbon deposition and oxidation of exsolved Ni nanoparticles, endowing the cell with stable operations for 200 h under these conditions and providing practical guidance for nanoscale heterointerface engineering in perovskite-ceria composite fuel electrodes.