Improving the activity and stability of Ni-based electrodes for solid oxide cells through surface engineering: Recent progress and future perspectives

Solid oxide cells (SOCs) have attracted great attention in the past decades because of their high conversion efficiency, low environmental pollution and diversified fuel options. Nickel-based catalysts are the most widely used fuel electrode materials for SOCs due to the low price and high activity. However, when hydrocarbon fuels are employed, nickel-based electrodes face serious carbon deposition challenges, leading to a rapid decline of cell performance. Great efforts have been devoted to understanding the occurrence of the coking reaction, and to improving the stability of the electrodes in hydrocarbon fuels. In this review, we summarize recent research progress of utilizing surface modification to improve the stability and activity of Ni-based electrodes for SOCs by preventing carbon coking. The review starts with a briefly introduction about the reaction mechanism of carbon deposition, followed by listing several surface modification technologies and their working principles. Then we introduce representative works using surface modification strategies to prevent carbon coking on Ni-based electrodes. Finally, we highlight future direction of improving electrode catalytic activity and anti-coking performance through surface engineering.