Structural, electrical and electrochemical properties of calcium-doped lanthanum nickelate

Correlation between Structural and Transport Properties of Ca-Doped La Nickelates and Their Electrochemical Performance

“…The relative density of the substrates calculated from their geometrical sizes and weight was 95%. Additionally, a LaNi 0.6 Fe 0.4 O 3 (LNF) powder for the formation of the electrode collectors was synthesized by a Pechini method; details of the synthesis procedure are given elsewhere [28,30]. The LNF powder possessed a rhombohedral structure (R3c sp.…”

“…It has been reported for La 2−x Sr x NiO 4+δ that when the strontium content is increased, the electrical conductivity significantly increases from 50 S cm −1 (at 1000 • C) for the undoped La 2 NiO 4+δ and up to 200-250 S cm −1 (at 1000 • C) for Sr-rich samples (x = 0.75, 1) [14,27]. For La 2−x Ca x NiO 4+δ , an increase in calcium content similarly elevates the total conductivity from 80-95 S cm −1 for the undoped La 2 NiO 4+δ and up to 90-165 S cm −1 (at 400 • C) for Ca-rich samples (x ≥ 0.2) [9,22,28,29]. Due to the lower substitution level for Ca in the La 2 NiO 4+δ compared with Sr, the attainable enhancement in conductivity is also lower.…”

“…Similarly, the oxygen mobility in the La 2−x Ca x NiO 4+δ (x = 0-0.2) series under a chemical potential gradient was reported to have a non-linear x dependence according to the electrical conductivity relaxation data, with the best properties for x = 0.1 [22]. According to isotope exchange of oxygen and ionic conductivity measurement data, a decrease in the oxygen tracer diffusion coefficient with Ca content was demonstrated to be associated with a reduction in highly mobile interstitial oxygen content as a charge-compensating mechanism while substituting La 3+ with Ca 2+ [19,28,29,31,32]. However, whether such a dependence is consistent or not still remains unclear.…”

Novel materials for solid oxide fuel cell technologies: A literature review

“…Among these compositions, lanthanum nickelates exhibit extremely high oxygen surface exchange coefficient [52], while Pr 2 CuO 4 -based composites present compatibility with commercial electrolyte materials [50], which makes them feasible for commercial applications. Lanthanum nickelates with several La contents have been studied by Ferkhi and Yahia [53], while Kolchugin et al [52] and Sharma et al [54] have investigated calcium-and praseodymium-doped lanthanum nickelates, respectively, with different content. Pr 2 CuO 4 -based composites were studied by Li et al [50] and Chiu et al [51].…”

“…Ferkhi and Yahia [53] [52], with x varying from 0 to 0.4. The powders were produced by the twostep solid state reaction method in which La 2 O 3 , NiO, CaCO 3 and SrCO 3 were the starting materials.…”