Reversible solid oxide cell(RSOC)is a new energy conversion device with significant applications,especially for power grid peaking shaving.However,the reversible conversion process of power generation/energy storage p...Reversible solid oxide cell(RSOC)is a new energy conversion device with significant applications,especially for power grid peaking shaving.However,the reversible conversion process of power generation/energy storage poses challenges for the performance and stability of air electrodes.In this work,a novel high-entropy perovskite oxide La_(0.2)Pr_(0.2)Gd_(0.2)Sm_(0.2)Sr_(0.2)Co_(0.8)Fe_(0.2)O_(3−δ)(HE-LSCF)is proposed and investigated as an air electrode in RSOC.The electrochemical behavior of HE-LSCF was studied as an air electrode in both fuel cell and electrolysis modes.The polarization impedance(Rp)of the HE-LSCF electrode is only 0.25Ω·cm^(2) at 800℃ in an air atmosphere.Notably,at an electrolytic voltage of 2 V and a temperature of 800℃,the current density reaches up to 1.68 A/cm^(2).The HE-LSCF air electrode exhibited excellent reversibility and stability,and its electrochemical performance remains stable after 100 h of reversible operation.With these advantages,HE-LSCF is shown to be an excellent air electrode for RSOC.展开更多
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supported by Fundamental Research Funds for the Central Universities(2023KYJD1008)the Science Research Projects of the Anhui Higher Education Institutions of China(2022AH051582).
文摘Reversible solid oxide cell(RSOC)is a new energy conversion device with significant applications,especially for power grid peaking shaving.However,the reversible conversion process of power generation/energy storage poses challenges for the performance and stability of air electrodes.In this work,a novel high-entropy perovskite oxide La_(0.2)Pr_(0.2)Gd_(0.2)Sm_(0.2)Sr_(0.2)Co_(0.8)Fe_(0.2)O_(3−δ)(HE-LSCF)is proposed and investigated as an air electrode in RSOC.The electrochemical behavior of HE-LSCF was studied as an air electrode in both fuel cell and electrolysis modes.The polarization impedance(Rp)of the HE-LSCF electrode is only 0.25Ω·cm^(2) at 800℃ in an air atmosphere.Notably,at an electrolytic voltage of 2 V and a temperature of 800℃,the current density reaches up to 1.68 A/cm^(2).The HE-LSCF air electrode exhibited excellent reversibility and stability,and its electrochemical performance remains stable after 100 h of reversible operation.With these advantages,HE-LSCF is shown to be an excellent air electrode for RSOC.
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.
