Work

Enhanced Performance of La 0.7 Sr 0.3 FeO 3- δ Cathode for SOFC via Implementation of B-site High-entropy Strategy

Year: 2024

Type: article

Abstract: As classical cathode materials of solid oxide fuel cell (SOFC), Fe-based perovskite materials are favored for their affordable price, low thermal expansion coefficient and high stability.In this study, B-site high-entropy perovskite oxide La 0.7 Sr 0.3 (FeNiCo) 0.8 Mo 0.1 Ti 0.1 O 3-δ (LSFNCMT) was prepared by the citric acid-nitrate combustion method.Due to the faster oxygen surface exchange rate of the high-entropy material, the LSFNCMT cathode shows excellent oxygen reduction reaction (ORR) activity with a polarization impedance (R p ) of 0.11 Ω•cm 2 at 800 ℃, which is much lower than that of the La 0.7 Sr 0.3 FeO 3-δ (LSF) cathode (0.31 Ω•cm 2 ).Furthermore, the high-entropy material exhibits superior stability due to incorporation of highly acidic Ni, Co, and Mo cations as well as Ti cation with more negative average bonding energy (ABE) of metal-oxygen.In the 22 h-stability test of the symmetric cell with LSFNCMT cathode in the Cr-containing atmosphere, R p only increases from 1.07 Ω•cm 2 to 2.98 Ω•cm 2 , while R p of the LSF cathode increases from 2.62 Ω•cm 2 to 7.90 Ω•cm 2 under the same conditions, indicating better Cr-resistance of LSFNCMT due to the high-entropy strategy.The fact that the maximum power density (MPD) of the single cell with LSFNCMT cathode at 800 ℃ is 1105.26mW•cm -2 , significantly higher than that of LSF cathode (830.74 mW•cm -2 ), and R p at 800 ℃ is 0.24 Ω•cm 2 , lower than that of LSF cathode (0.36 Ω•cm 2 ), confirming excellent toxicity resistance of the high-entropy cathode.This study shows that B-position high entropy is an effective way to improve the catalytic activity and chromium resistance of cathode materials.

Source: Journal of Inorganic Materials

DOI: 10.15541/jim20240410