Synthesis and investigation on microstructure and electrical conductivity of Ruddlesden-Popper phase, La1.9Sr0.1Ni0.7Cu0.3O4 (LSNC), as cathode material for intermediate temperature solid oxide fuel cells

Abstract

In the present work, a Ruddlesden-Popper oxide, La1.9Sr0.1Ni0.7Cu0.3O4 (LSNC), has been synthesized by solid state reaction for Intermediate-Temperature Solid Oxide Fuel Cells (IT-SOFCs) applications. To investigate the effect of sintering temperature on the microstructure and electrical properties, the LSNC cathode samples were fired in the temperature range of 1000–1300 °C. The crystal structure and microstructures of the synthesized and fired samples were studied by XRD and SEM, respectively. The electrical conductivity of the monolithic electrodes is investigated experimentally through the four-probe method as a function of temperature in the range of 300 – 800 oC. Our investigation revealed that the LSNC material behaves like semiconductor materials; the conductivity increases by increasing the temperature up to a specific temperature but then decreases with further temperature increases. It has also been proven that an increase in sintering temperature leads to increasing electrical conductivity. The maximum total electrical conductivity of 67.57 S cm−1 at 450 °C was recorded for pure LSNC material sintered at 1300 °C.