Highly active and novel A-site deficient symmetric electrode material (Sr0.3La0.7)1-x (Fe0.7Ti0.3)0.9Ni0.1O3-δ and its effect on electrochemical performance of SOFCs

A-site deficient (Sr0.3La0.7)(1-x) (Fe0.7Ti0.3)(0.9)Ni0.1O3-delta ((SL)(1-x)FTN) symmetrical electrodes with compositions x = 0.1, 0.2 and 0.3 denoted as SLFTN-01, SLFTN-02, and SLFTN-03 respectively were synthesized via modified Pechini method. The as prepared samples were further coated on LGSM electrolyte through screen-printing technique. Electrochemical performance was significantly improved for A-site deficient (SL)(1-x)FTN due to increased concentration of oxygen vacancy. XRD patterns revealed better reversibility for (SL)(1-x)FTN with rhombohedral structure. Low polarization resistance (Rp) similar to 0.210, 0.195 and 0.165 Omega cm(2) (in dry H-2) and 0.069, 0.046 and 0.043 Omega cm(2) (in air) was measured for SLFTN-01, SLFTN-02, and SLFTN-03 respectively at a temperature of 750 degrees C. Highest conductivities similar to 326, 338 and 342 Scm(-1) were calculated in air and the conductivities obtained in dry H-2 were similar to 0.64, 0.81 and 1.01 Scm(-1) at 700 degrees C. It was observed that small polaron mechanism was responsible for the decreased conductivity with the increased temperature range. The fabricated symmetrical cell ((SL)(1-x)FTN/LDC vertical bar LSGM vertical bar LDC/(SL)(1-x)FTN), maintained good stability without any degradation during the test time similar to 500 h (in air) and 100 h (in dry H-2). The detailed investigations categorized the fabricated cells well suited as anode and cathode with improved performance and excellent stability both in oxidizing and reducing atmospheres. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

A-site deficient symmetrical electrodes were synthesized and exhibited significantly improved electrochemical performance with better reversibility and lower polarization resistance. High conductivities and stability were observed at different temperatures.