Characterization of B‐Site Sc‐doped La2Ni1-xScxO4+δ (x=0, 0.05, 0.10, and 0.15) perovskites as cathode materials for IT-SOFCs

Abstract

Cathode materials play a crucial role in enabling the widespread adoption of intermediate-temperature solid oxide fuel cells (IT-SOFC) for commercial applications. This study utilized the sol-gel method to prepare a range of perovskite oxides, specifically Sc-doped La2Ni1-xScxO4+δ (x = 0, 0.05, 0.10, and 0.15), without the use of cobalt. The investigation focused on making a study of how the introduction of Sc doping affected the thermal stability, electrochemical properties, and structure of cathode materials. XRD, FE-SEM, and electrochemical workstations were subjected to structural characterization and performance testing of materials. The findings indicate that all the prepared materials have a typical Ruddlesden-Popper structure, and an abundance of additional oxygen can be generated in close proximity to the interstitial by incorporating Sc into the cathode of La2Ni1-xScxO4+δ to increase the oxygen vacancy and improve the catalytic activity of ORR. La2Ni0.9Sc0.1O4+δ has the highest oxygen surface exchange kinetics, the dissociative adsorption of oxygen is the rate-limiting step at the cathode. At a temperature of 700 °C, the lowest polarization resistance of La2Ni0.9Sc0.1O4+δ is 0.1298 Ω cm2, while the single cell with La2Ni0.9Sc0.1O4+δ as the cathode achieves an impressive peak power density of 0.462 W cm−2, thus demonstrating exceptional long-term stability. La2Ni0.9Sc0.1O4+δ is expected to be a potential high-performance IT-SOFC cathode material.