Advances in understanding and mitigating Ni-based electrodes degradation in solid oxide fuel cells and electrolysis cells

Solid oxide fuel/electrolysis cells (SOFCs/SOECs) are highly efficient electrochemical energy conversion devices, with the former capable of converting fuel to electricity and the latter capable of converting electricity to fuel. However, the commercialization of SOFCs/SOECs is hindered by performance degradation due to the coarsening and migration of traditional nickel-based fuel electrodes during prolonged operation. This review provides a discussion on the evolution of Ni coarsening and migration in fuel electrodes, methods for characterizing Ni-based electrodes degradation, and strategies to mitigate the evolution of Ni electrodes, with a focus on alternative fuel electrode materials. Specifically, we comprehensively review the mechanisms of Ni coarsening and migration, the impact of Ni-based electrodes degradation on cell performance, strategies to combat Ni agglomeration and migration, and the development of novel anti-Ni coarsening and migration fuel electrode materials. Additionally, we detail the advances in Ni agglomeration and migration research from the perspectives of simulation, computation, and kinetic models. Finally, future research directions for fuel electrodes resistant to Ni agglomeration and migration are proposed, with particular emphasis on the potential of multi-objective optimization coupled with AI-driven optimization.