The Composite La_2-xNd_<i>x</i>Ce₂O_7-δ Material for New Energy Conversion Devices: A Physiochemical and Electrochemical Study

In this study, the composite La2-xNdxCe2O7-δ with different concentrations of La3+ and Nd3+ in ceria is prepared through the sol–gel method for a new energy conversion device referred to as single-component solid oxide fuel cell (SC-SOFC). The XRD patterns reveal a fluorite cubic structure for all La2-xNdxCe2O7-δ samples. The SEM analysis revealed that La2-xNdxCe2O7-δ (x = 0.5, 1, 1.5) materials exhibit fine agglomeration of irregular grains and nonhomogeneous flakes for the La2-xNdxCe2O7 (x = 0 and 2) samples. Furthermore, FTIR results indicate the presence of nitrates in the composites. In Raman spectra, the F2g mode is associated with the space group (Fm3m), which confirms the fluorite structure. Further, Raman spectroscopy shows the shifting of peaks to higher frequencies for La2-xNdxCe2O7-δ (x = 0.5, 1, 1.5) samples. The conductivity of La1.5Nd0.5Ce2O7-δ material shows an exceptional result, with a total conductivity of 0.10 S cm–1 at 600 °C. The Nyquist plot of sample La1.5Nd0.5Ce2O7-δ shows a reduction of ohmic resistance (Ro) with increasing temperature, confirming the stability for all prepared materials. The La1.5Nd0.5Ce2O7-δ composite shows a maximum power density of ∼639 mW cm–2 at 600 °C. Therefore, the composite La2-xNdxCe2O7-δ with Ni0.8Co0.15Al0.05LiO2 as a semionic conductor has good potential as a single-component energy conversion device.