Study of Nd2–xCexCuO4 ± δ (x = 0.1–0.25) as cathode material for intermediate-temperature solid oxide fuel cells

The solid solubility limit of Ce in Nd2–xCexCuO4 ± δ, prepared by sol–gel process, is established up to x = 0.2. The transition from negative temperature coefficient to positive temperature coefficient, within the solid solubility region, is observed at 620 °C. The area-specific-resistance (ASR) is optimized for electrochemical cell sintered at 800 °C. ASR enhances with increase in sintering temperature of cell. ASR value of 0.93 ohm cm2 at 700 °C, determined by electrochemical impedance spectroscopy is comparable against that by voltage versus current (V–I) characteristics at 0.98 ohm cm2 at the same temperature. Electrochemical performance and ASR of Nd1.8Ce0.2CuO4 ± δ is improved when prepared by sol–gel route over solid-state reaction, which is attributed to uniform size and shape of nanocrystalline grains.