Calcium doping in double perovskite SmBa1-xCaxCo2O5,δ to enhance the electrochemical activity of solid oxide cell reversible oxygen electrode

Despite the remarkable reduction of carbon emissions due to COVID-19 pandemic during 2020, a reckless energy demand has compromised the 2050 agenda. In this scenario, reversible Solid Oxide Cells (rSOCs) could play a key-role due to their high fuel flexibility and versatility but there is still room for electrode stability and performance improvement. Lately, double perovskite materials have been widely studied due to their extraordinary fast oxygen diffusion rates and high conductivity mainly related to their layered ordering structure. In this work, the authors present the synthesis route and the electrochemical char-acterization of the A-site layered double perovskite structure SmBa1-xCaxCo2O5,delta in which calcium co -doping demonstrates a remarkable effect in the oxygen electrode activity. The best calcium doping corre-sponding to SmBa0.8Ca0.2Co2O5,delta displays a Rp reduction from 0.082 for the undoped material to 0.019 ohm middotcm2 at 700 degrees C. Moreover, under anodic and cathodic operating conditions the electrocatalytic ac-tivity was further increased to 0.007 and 0.006 ohm middotcm2 at eta = +/- 0.3 V, respectively. This behaviour de-monstrates the suitability of the material to work as reversible oxygen electrode. Finally, the electrode material was subjected to a switching current aging test for over 100 h to prove the electrode stability under operating conditions.(c) 2022 Elsevier B.V. All rights reserved.

Automated summary

Despite the reduction in carbon emissions during 2020 due to the COVID-19 pandemic, the increased energy demand poses a challenge to the 2050 agenda. Reversible Solid Oxide Cells (rSOCs) show promise in addressing this challenge with their fuel flexibility and versatility. The use of double perovskite materials in rSOCs is explored in this study, focusing on their oxygen electrode activity and stability.