Synthesis and electrochemical performance of Ruddlesden-Popper cathodes La1.5Nd0.3Pr0.2NiO4 and La1.5Pr0.5NiO4 for solid oxide fuel cells

This study focuses on the synthesis of Ruddlesden-Popper oxide materials (A₂BO₄), specifically La_1.5Nd_0.5Pr_0.2NiO₄ (LNPNO) and La_1.5Pr_0.5NiO₄ (LPNO), using the nitrate-citrate method. These materials are then evaluated as cathodes for solid oxide fuel cells (SOFCs). Scanning electron microscopy (SEM) reveals agglomerated grains with interconnected porosity, while Fourier-transform infrared (FTIR) spectroscopy confirms the formation of the desired bonds. Electrochemical performance is assessed using two different cell configurations. The conventional cell configuration shows that, while LNPNO exhibited relatively low catalytic activity, LPNO demonstrated electrochemical behavior comparable to the conventional LSM (lanthanum strontium manganite)-YSZ (yttria-stabilized zirconia) composite cathode, even without the addition of an ionic conducting phase. Cell performance is further enhanced by incorporating a nanostructured anode and an interlayer between the electrolyte and cathode; however, the interlayer also increases the ohmic resistance. Notably, the cell with the LPNO cathode outperforms the reference conventional cell, especially at lower operating temperatures. These findings highlight the potential of LPNO as a promising cathode material for intermediate-temperature SOFCs.