Development of Ammonia Fueled Solid Oxide Fuel Cells

Solid oxide fuel cells (SOFCs) can generate electricity through an electrochemical conversion of the chemical energy of fuels including hydrogen, hydrocarbons, and biogas because of high operation temperatures. Ammonia has recently been considered as a promising hydrogen carrier that is relatively convenient to store and transport and can be decomposed into hydrogen and nitrogen with no carbon emission via catalytic cracking. Thus, much effort has been made to utilize ammonia as a clean fuel to SOFCs for power generation at high efficiency. This review is aiming at delivering the current progress of developing high temperature ceramic fuel cells fed with ammonia, particularly more focused on the achievements of a direct ammonia fueled SOFC (DA-SOFC) to shed light on the challenges of degrading the performance and durability. The problems are primarily attributed to a lack of rational catalysts, thermal imbalance, and the evolution of nitrides on the components including the Ni based anode, Ni mesh as current collector, and stainless steels of metallic interconnect that are exposed to the ammonia fuel environment incurring microstructural deformations and electrical and electrochemical deteriorations. Lastly, strategic pathways to overcome the inadequate performance and the instability are suggested to accomplish a commercialization of DA-SOFCs.