The influence of preparation pressure on the electrochemical performance of semiconductor-ionic membrane fuel cells (SIMFC)

Recently, semiconductor-ionic membrane fuel cells (SIMFC) has been widely reported due to its excellent power output. In general, the SIMFCs were fabricated by dry pressing method without high-temperature sintering, thus the preparation pressure is bound to affect the microstructure of electrolyte and electrode and further determine the cell performance. To detect the influence of preparation pressure, SIMFC based on La and Pr co-doped CeO₂–Ni_0.8Co_0.15Al_0.05LiO_2−δ electrolyte was fabricated under different preparation pressure. The evolution of cell microstructure and cell performance with preparation pressure were systematically characterized to obtain the optimal pressure. The characterizations revealed that the increase of preparation pressure gave rise to the enhancement of electrolyte density and the decrease of the electrode porosity, and further brought about the improvement of the gas tightness of the electrolyte membrane and the decrease of three reaction phase area of electrode; the two factors gave the opposite effect to the cell performance and reached a balance at certain preparation pressure. Therefore, the performance of the assembled cell initially increases and then decreases with the increase of preparation pressure, an optimal performance, i.e., a power maximum of 833 mW cm⁻² and open circuit voltage of 1 V, was obtained at 550 °C when the preparation pressure is 10 MPa.