A Mini-Review on Mitigating Degradation of Metallic Interconnects in Solid Oxide Cell Stack Systems: Advances, Challenges, and Solutions

Metallic interconnects (MICs) are critical components in solid oxide cell (SOC) stack systems, facilitating efficient power generation and fuel production. Despite their cost-effectiveness, high conductivity, and manufacturability advantages over ceramic alternatives, MICs face significant degradation challenges during high-temperature operations. Key issues encompass dual-atmosphere exposure, element interdiffusion, chromium volatilization, and subsequent electrode poisoning, which collectively deteriorate the performance of SOC stack systems. This review comprehensively consolidates recent advancements in mitigating these detrimental impacts through two primary strategies: surface modification via protective coatings (e.g., perovskite, spinel, reactive elements, and composite coatings) and composition modulation via element doping (e.g., alloying with Ti, Nb, Mo, W, or Mn). The efficacy of protective coatings in suppressing Cr evaporation and reducing area-specific resistance is critically assessed, alongside novel alloy designs that enhance oxidation resistance and thermal stability. Furthermore, deposition technologies, such as screen printing, physical vapor deposition, electrophoretic deposition, and thermal spraying, are evaluated with respect to their performance and scalability. The synthesized insights provide feasible pathways for the optimization of MIC durability and SOC stack efficiency, ultimately supporting the commercialization of SOC technology for sustainable energy applications.