Alkali Metal Ion Migration Modulation-Induced High-Performance Low-Temperature Solid Oxide Fuel Cells

Abstract Reducing the operating temperature while maintaining a stable performance is a key challenge for solid oxide fuel cells (SOFCs). Here, we improve the performance of low-temperature SOFCs by modulating the migration of alkali metal ions within the cell. To visualize the migration pathways of alkali metal ions, Na is doped into the LiNi0.8Co0.15Al0.05O2–δ (NCAL) electrode. The migration pathways and chemical states of alkali metal ions within the cell are investigated. Results suggest that the migration of Li/Na-species depends on temperature, electric field, and gas atmosphere, affecting ion transport and oxygen reduction reaction. By modulating the migration behavior of Li/Na-species through adjustments in preheating temperature, H2 pre-reduction, and Na doping concentration, the fuel cell performance is optimized. Notably, Na doping enhances cell stability, enabling over 600 h of operation. This study provides important insights into the understanding and modulation of the migration behavior of alkali metal-species in SOFCs to improve performance.