A review of advanced SOFCs and SOECs: Materials, innovative synthesis, functional mechanisms, and system integration

Solid oxide fuel cells (SOFCs) and solid oxide electrolysis cells (SOECs) are next-generation energy conversion technologies that have attracted widespread attention due to their high efficiency, fuel flexibility, and environmental friendliness. The reversible reaction processes of the two can achieve power generation and energy storage in one device. This paper provides an extensive overview of the latest developments in the field of SOFCs and SOECs, including types, material synthesis, mechanism research, and system integration. First, we introduce the classification of current SOFCs/SOECs according to their different supports and conducting ions. Then, we summarize the synthesis methods and optimization strategies for key materials, including the latest developments in electrolytes, electrodes, and interconnects. Subsequently, the electrochemical mechanisms, including ion transport, electron conduction, electrochemical reaction kinetics, and interfacial phenomena, are analyzed in depth. This paper also outlines challenges and strategies for system integration, such as thermal management, fluid dynamics, and mechanical stress control. Through comprehensive analysis, this review aims to provide researchers with a holistic perspective and guidance for the future development of SOFCs and SOECs. We close by discussing the main challenges and future research directions for further promoting the commercialization and large-scale development of these technologies.