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...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(Rp)of 0.11Ω·cm^(2) at 800℃,which is much lower than that of the La_(0.7)Sr_(0.3)FeO_(3-δ)(LSF)cathode(0.31Ω·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,Rp only increases from 1.07Ω·cm^(2) to 2.98Ω·cm^(2),while Rp of the LSF cathode increases from 2.62Ω·cm^(2) to 7.90Ω·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 1105.26 mW·cm^(-2),significantly higher than that of LSF cathode(830.74 mW·cm^(-2)),and Rp at 800℃is 0.24Ω·cm^(2),lower than that of LSF cathode(0.36Ω·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.展开更多
基金Key-Area Research and Development Program of Guangdong Province(2022B0111130004)National Natural Science Foundation of China(52272257)。
文摘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(Rp)of 0.11Ω·cm^(2) at 800℃,which is much lower than that of the La_(0.7)Sr_(0.3)FeO_(3-δ)(LSF)cathode(0.31Ω·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,Rp only increases from 1.07Ω·cm^(2) to 2.98Ω·cm^(2),while Rp of the LSF cathode increases from 2.62Ω·cm^(2) to 7.90Ω·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 1105.26 mW·cm^(-2),significantly higher than that of LSF cathode(830.74 mW·cm^(-2)),and Rp at 800℃is 0.24Ω·cm^(2),lower than that of LSF cathode(0.36Ω·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.
