Electrospinning of porous fiber-electrode materials for solid oxide fuel cells: Fundamentals and challenges.

In recent years, due to the improvement of material properties and the optimization of electrode microstructure through processes such as electrospinning, the maximum power density (MPD) of solid oxide fuel cells (SOFCs) in the medium operating temperature range has been elevated to a level of 2–3 W cm−2 and has demonstrated stable performance during long-term tests lasting 300–500 h. Electrospinning facilitates the preparation of fiber electrodes for SOFCs, which exhibit high porosity, high triple phase boundary (TPB) density, and high electrochemical activity. When combined with the impregnation process, it can further create unique electrode structures, enhancing the output power and durability of the cells. However, the production of fiber electrodes via electrospinning is constrained by production efficiency, and subsequent electrode preparation processes such as calcination, grinding, and sintering. These processes can easily lead to the destruction of the continuous-fiber morphology, posing challenges for electrospinning. This paper provides a comprehensive discussion on the key process parameters of electrospinning, enhancing preparation efficiency, preserving the continuous morphology of fibers, and recent advancements in the performance of fiber electrodes for SOFCs. Research on maintaining the continuous-fiber morphology inside electrodes is a key focus. The porosity and the durability of fiber-electrodes are also explored. • Key parameters of electrospun fiber electrodes are reviewed. • Focus is on preparation efficiency and fiber morphology disruption. • Area specific resistance, power density, porosity, and durability are reviewed. • Latest designs and surface modifications of fiber electrodes are explored. [ABSTRACT FROM AUTHOR]