TY - JOUR

T1 - Oxygen exchange and transport properties of the first-order Ruddlesden-Popper phase La2Ni0.9Co0.1O4+δ

AU - Eisbacher-Lubensky, Sarah Laura

AU - Egger, Andreas

AU - Sitte, Werner

AU - Bucher, Edith

N1 - Publisher Copyright: © 2023 The Authors

PY - 2023/9

Y1 - 2023/9

N2 - The rare earth nickelate La2Ni0.9Co0.1O4+δ (LNCO) was synthesized via the citrate/EDTA method. X-ray powder diffraction confirmed that the material is single-phase and crystallizes in the orthorhombic K2NiF4-type structure. In-situ dc-conductivity and conductivity relaxation measurements on a bar-shaped sample were applied to determine the electronic conductivity as well as the chemical surface exchange coefficient and chemical diffusion coefficient of oxygen from 600 °C to 850 °C and 0.01 ≤ pO2 / bar ≤ 0.1. The results indicate that substitution of nickel with cobalt in La2Ni0.9Co0.1O4+δ leads to significantly higher values of the surface exchange coefficient compared to La2NiO4+δ, while the electronic conductivity is somewhat reduced. The oxygen non-stoichiometry of LNCO was studied by thermogravimetry in the same temperature and oxygen partial pressure range. The measured thermal expansion coefficients of LNCO fit well with those of common solid electrolytes such as GDC and YSZ. Self-diffusion coefficients of oxygen and ionic conductivities were calculated from the experimentally determined diffusivities and the thermodynamic factor of oxygen by using the Nernst-Einstein relation. The results indicate that LNCO offers an attractive option for application as air electrode in solid oxide cells.

AB - The rare earth nickelate La2Ni0.9Co0.1O4+δ (LNCO) was synthesized via the citrate/EDTA method. X-ray powder diffraction confirmed that the material is single-phase and crystallizes in the orthorhombic K2NiF4-type structure. In-situ dc-conductivity and conductivity relaxation measurements on a bar-shaped sample were applied to determine the electronic conductivity as well as the chemical surface exchange coefficient and chemical diffusion coefficient of oxygen from 600 °C to 850 °C and 0.01 ≤ pO2 / bar ≤ 0.1. The results indicate that substitution of nickel with cobalt in La2Ni0.9Co0.1O4+δ leads to significantly higher values of the surface exchange coefficient compared to La2NiO4+δ, while the electronic conductivity is somewhat reduced. The oxygen non-stoichiometry of LNCO was studied by thermogravimetry in the same temperature and oxygen partial pressure range. The measured thermal expansion coefficients of LNCO fit well with those of common solid electrolytes such as GDC and YSZ. Self-diffusion coefficients of oxygen and ionic conductivities were calculated from the experimentally determined diffusivities and the thermodynamic factor of oxygen by using the Nernst-Einstein relation. The results indicate that LNCO offers an attractive option for application as air electrode in solid oxide cells.

UR - http://www.scopus.com/inward/record.url?scp=85158023899&partnerID=8YFLogxK

U2 - 10.1016/j.ssi.2023.116255

DO - 10.1016/j.ssi.2023.116255

M3 - Article

VL - 397.2023

JO - Solid State Ionics

JF - Solid State Ionics

SN - 0167-2738

IS - September

M1 - 116255

ER -