Flat-tube solid oxide stack with high performance for power generation and hydrogen production

This study presents the design, fabrication, and evaluation of a high-performance flat-tube solid oxide cell (FT-SOC) stack, which demonstrates exceptional power generation and hydrogen production capabilities. Comprising three large-sized FT-SOCs, each with an active area of 60 cm2, the stack was tested at 750 °C. It achieved a peak power density of 1.222 W/cm2 in fuel cell (FC) mode and an electrolysis current density of 1.283 A/cm2 at an average voltage of 1.3 V in electrolysis cell (EC) mode, marking the highest reported values for FT-SOC stacks to date. These results surpass the performance of most large-sized planar SOC stacks. Post-operation analysis revealed excellent interfacial contact between components, contributing to the stack's high performance. This study underscores the potential of FT-SOCs in efficient power generation and electrolytic energy storage applications, providing insights that could facilitate their industrial application. •A three-cell flat-tube stack with ultra-high performance was developed.•The flat-tube stack achieved 1.222 W/cm2 in FC mode.•The current of the stack achieved 1.283 A/cm2 at thermal neutral voltage in EC mode.•The total ohmic resistance of the cells in the stack was only 8.2 mΩ.•The ohmic resistance of interconnects and end plates accounted for 7.6% of the stack.