| Abstract Scope |
High-temperature solid oxide electrochemical devices are efficient, versatile platforms for producing clean electricity and hydrogen. Within their multilayer structures, space charges with distinctive electrical properties form at interfaces. Herein, we unveil the fundamental nature of space charges and present a novel electrode design achieved through their precise manipulation. By interfacing with electron-conducting nanoparticles, a localized electron-rich zone is created within the ion-conducting framework. Using a highly controllable synthesis technique, we achieved a well-ordered nanoparticle configuration with critical inter-particle distances, enabling the overlap of space charge zones and the formation of continuous electron conduction pathways. This approach resulted in a highly efficient electrode with balanced electronic and ionic conductivities, as well as a nanocatalyst-enriched active surface. The electrode demonstrated exceptional performance and stability in realistic applications, including commercial-scale large cells, significantly outperforming the state-of-the-art composite electrodes. These findings validate the feasibility of space-charge engineering for practical, real-world applications. |