Design of nanofiber-based electrodes for solid oxide electrochemical cells with high performance and stability†

We demonstrated a La_0.6Sr_0.4CoO_3−d (LSC) nanofiber-based electrode for solid oxide electrochemical cells operating at intermediate temperatures. A thin powder layer deposited at the interface between the nanofiber layer and electrolyte significantly enhanced the adhesion strength, facilitating operation of a porous and hollow nanofiber structure with a high specific surface area and high concentration of oxygen vacancies at a low sintering temperature. The optimized nanofiber-based single cell achieved a significantly improved peak power density of 1 W cm⁻² in fuel-cell mode and current density of 0.79 A cm⁻² at 1.3 V under 50% H₂–50% steam conditions in electrolysis-cell mode at 600 °C with excellent thermal stability under static and reversible cyclic operations. These results demonstrated the feasibility of the nanofiber-based electrode in achieving high performance and stability in solid oxide electrochemical cells operating at intermediate temperatures.