Performance of Ni-Fe bimetal based cathode for intermediate temperature solid oxide electrolysis cell

Abstract To enhance the performance of an Ni-based cathode in a solid oxide electrolysis cell (SOEC) at medium temperature (600–800 °C), the present study adopted the method of adding Fe to Ni to fabricate Ni-Fe bimetal. Adding Fe can effectively inhibit Ni particles from becoming coarsen to enhance performance of Ni-based cathode. In the present study, the effects of different Fe contents in Ni1-xFex (x = 0, 0.1, 0.2, 0.3, 0.4, 0.5) bimetallic materials on the performance of the Ni-based cathode for SOECs were systematically studied, and the optimal Fe content for Ni-Fe bimetallic materials suitable for use as the cathode of a SOEC was ascertained. The optimal Fe molar content is 40%. Under the open circuit voltage, the SDC-Ni0.6Fe0.4 based SOEC has a lower polarization impedance than other SOECs. Besides, at the same cell potential, the SDC-Ni0.6Fe0.4 based SOEC has a higher current than other SOECs. Furthermore, the SDC-Ni0.6Fe0.4 based SOEC exhibits good stability. Accordingly, this study proved that Ni-Fe bimetal with an appropriate proportion can enhance the performance of Ni-based cathode, and it was also demonstrated that at medium temperature, this material acts as an excellent cathode for a SOEC.