LaCoO3 – δ as the Material of an Oxygen Electrode for a Molten Carbonate Fuel Cell: I. Electrophysical Properties of Lithiated LaCoO3 – δ

• Published in: Russian metallurgy Metally 2018-02, Vol.2018 (2), p.149-154
• Main Authors: Vecherskii, S. I., Konopel’ko, M. A., Antonov, B. D., Batalov, N. N., Zvezdkin, M. A., Zvezdkina, I. V.
• Format: Article
• Language: English
• Subjects: Chemistry and Materials Science; Electrical resistivity; Fuel cells; Lithium oxides; Materials Science; Metallic Materials; Molten carbonate fuel cells; Operating temperature; Perovskites; Solid solutions
• ISSN: 0036-0295; 1555-6255; 1531-8648
• DOI: 10.1134/S0036029518020209

Oxides LaCoO 3 – δ + ( z /2) Li 2 O (0 ≤ z ≤ 0.15) are synthesized to determine the boundaries of changing the electrophysical properties of LaCoO 3 – δ due to its in situ lithiation in the (Li 0.62 K 0.38 ) 2 CO 3 eutectic melt. A perovskite-like solid solution (La 1 – x Li x )(Li x Co 1 – x )O 3 – δ , where x = z /( z + 2), is found to form as a result of Li doping. The region of existence of the solution does not exceed 2 x = 0.072. At a higher concentration of Li, LiCoO 2 forms along with the perovskite-like phase. At the operating temperature of the carbonate fuel cell ( T = 920 K), the single-phase samples have metallic conduction and positive thermopower. The electrical conductivity of the Li-doped samples decreases as compared to that of LaCoO 3 – δ by no more than 1.5 times and varies from 3.2 × 10 4 to 3.8 × 10 4 S/m.