Influence of synthesis route on electrical and electrochemical properties of Nd1.8Sr0.2NiO4 + δ

The Nd1.8Sr0.2NiO4 + δ was prepared by sol–gel, microwave combustion and solid-state reaction. The highest dc conductivity (σ = 61 S cm− 1 at 660 °C) for sol–gel derived Nd1.8Sr0.2NiO4 + δ compared to those prepared by microwave combustion and solid-state reaction was due to lowest crystallite size (165.92 nm) and high sintered density (90%). Symmetric cells configured as cathode/electrolyte/cathode were fabricated by spin coating the cathode ink on gadolinium doped ceria (GDC) electrolyte. The lowest area specific resistance (ASR) value of 0.6 Ω cm2 was obtained at 700 °C for sol–gel derived Nd1.8Sr0.2NiO4 + δ. Particle size distribution of Nd1.8Sr0.2NiO4 + δ cathode was largely dependent on the synthesis route, and that influenced the ASR. Electrochemical performance suggests absorption of oxygen by Nd1.8Sr0.2NiO4 + δ lattice is the rate-limiting step.