Electrochemical performance of Nd1.8Ce0.2CuO4 ± δ mixed-ionic–electronic conductor for intermediate solid oxide fuel cells

The ball-mill assisted solid-state reaction gave nanocrystalline Nd1.8Ce0.2CuO4 ± δ solid solution. Its crystal structure estimated by Rietveld analysis revealed decreased space in rock salt layer on partial replacement of Nd3+ by Ce4+. The dc conductivity was reduced when the sample was sintered at high temperature (at 1100 °C) due to random growth of the grains. The sintering temperature of the cells was optimized to 1000 °C in terms of lowest area-specific resistance (ASR) = 1.62 Ω cm2. The transition from positive temperature coefficient (PTC) to negative temperature coefficient (NTC) in Nd1.8Ce0.2CuO4 ± δ found at 630 °C in dc conductivity coincided with the transition in temperature dependent ASR study. The electrochemical performance of Nd1.8Ce0.2CuO4 ± δ is discussed in the light of oxygen absorption by the lattice.