Reversible operation of La0.8Sr0.2MnO3 oxygen electrode infiltrated with Ruddlesden-Popper and perovskite lanthanum nickel cobaltite

The electrochemical performance and stability of La0.8Sr0.2MnO3 oxygen electrodes infiltrated with La2Ni0.5Co0.5O4 (Ruddlesden-Popper) and La2Ni0.5Co0.5O3 (perovskite) nano particles were studied under cyclic solid oxide electrolysis cell and solid oxide fuel cell modes. Electrochemical impedance spectroscopy and analysis of distribution of relaxation times were utilized to investigate the effect of addition of catalysts with RuddlesdenPopper and perovskite structures on the reversible operation of electrochemical cells. Results indicated that addition of La2Ni0.5Co0.5O4 nanoparticles has more impact on polarization resistance reduction as compared to La2Ni0.5Co0.5O3 in cyclic operation, probably due to the facile oxygen transport in the rock salt layer of Ruddlesden-Popper structure. Analysis of the polarization resistance fluctuations shows a better stability in RuddlesdenPopper structure-infiltrated electrodes as compared to perovskite structure. The difference between maximum and minimum of polarization resistances (i.e. fluctuations) in cyclic operation is reduced significantly by introducing Ruddlesden-Popper-structured lanthanum nickel cobaltite nanoparticles. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.