Advancements, strategies, and prospects of solid oxide electrolysis cells (SOECs): Towards enhanced performance and large-scale sustainable hydrogen production

Solid oxide electrolysis cells (SOECs) represent a crucial stride toward sustainable hydrogen generation, and this review explores their current scientific challenges, significant advancements, and potential for large-scale hydrogen production. In SOEC technology, the application of innovative fabrication techniques, doping strategies, and advanced materials has enhanced the performance and durability of these systems, although degradation challenges persist, implicating the prime focus for future advancements. Here we provide in-depth analysis of the recent developments in SOEC technology, including Oxygen-SOECs, Proton-SOECs, and Hybrid-SOECs. Specifically, Hybrid-SOECs, with their mixed ionic conducting electrolytes, demonstrate superior efficiency and the concurrent production of hydrogen and oxygen. Coupled with the capacity to harness waste heat, these advancements in SOEC technology present significant promise for pilot-scale applications in industries. The review also highlights remarkable achievements and potential reductions in capital expenditure for future SOEC systems, while elaborating on the micro and macro aspects of SOECs with an emphasis on ongoing research for optimization and scalability. It concludes with the potential of SOEC technology to meet various industrial energy needs and its significant contribution considering the key research priorities to tackle the global energy demands, fulfillment, and decarbonization efforts.