In this work, a kind of thin K‐type thermocouple and self‐developed CAS‐I sealant were used to assembly solid oxide fuel cell (SOFC) stacks and temperatures of unit cells inside a planar SOFC stack were measured. The open circuit voltage testing of the stack and characterization of the interface between sealant and components suggested excellent sealing effect by applying the developed method. The effect of discharging direct‐current on temperature and temperature distribution inside the designed SOFC stack was investigated. The results showed that the discharging current had a great impact and the gas flow rate had a slight impact on the temperatures of unit cells. Temperature distribution of unit cells inside the stack was much non‐uniform and there is a significant temperature difference between various components of the stack and heating environment. The relationship between temperatures and cell performance showed that the worse the cell performance, the higher the cell surface temperature. When the stack was discharged at a constant current and the temperature of cell surface was over 950 °C, the higher the temperature, the more drop the corresponding voltage.

This work investigates the effect of contact between electrodes and alloy interconnects on output performance of solid oxide fuel cell (SOFC) stacks. The measured maximum output power density (pmax) of the unit cell increases from 0.07 to 0.1 W cm–2 by increasing the tip area of the interconnect from 40 to 60 cm2. The pmax increases from 0.07 to 0.15 W cm–2 upon the addition of nickel foam and Ag mesh on the anode and cathode side, respectively. An additional (La0.75Sr0.25)0.95MO3–σ cathode current collecting layer is re‐printed on the original cathode current collecting layer, which aims to further improve the performance of the stack and individual cell. The performance of a 3‐cell short stack assembled by the cells with a new cathode current collecting layer is evaluated by measuring the current–voltage curve. The results indicate that the pmax values of the stack and individual cells are enhanced from 0.07 to 0.37 W cm–2 and 0.15 to 0.5 W cm–2 at 850 °C, respectively. The performance of the whole stack and individual cells is greatly improved due to the interconnect embedded in the re‐printed new cathode current collecting layer.

No abstract