Design of Nano‐Composite Structured Electrode for High‐Performance and Stability of Metal‐Supported Solid Oxide Cells

Abstract Solid oxide cells are reversible energy‐conversion devices for electric power generation and fuel production with high efficiency. However, robust cell structures and multifunctional electrodes must be provided to achieve high cell performance under multifuel conditions. Herein, a precisely controlled metal‐supported structure and dual‐nanocomposite catalyst is presented. The thermal and shrinkage behaviors of the metal supports play a crucial role in determining the interconnectivity between cell components. Compared to micron‐sized cermets, the dual‐nanocomposite electrode with tremendous three‐phase boundaries drastically improves cell performance by increasing the electrochemical activity for diverse fuel reactions. The developed cells exhibited outstanding maximum power densities of 1.1 and 1.0 W cm⁻² in fuel‐cell mode using H₂ and CO fuels, and current densities of −0.61 and −0.5 A cm⁻² in electrolysis‐cell mode (1.3 V) under H₂O/H₂ and CO₂/CO conditions at 650 °C. These findings suggest fundamental techniques for improving the structural stability and activity of cell components to operate in diverse fuel systems.