| Solid oxide fuel cell(Solid Oxide Fuel Cells,SOFCs)is an electrochemical device that can directly convert the chemical energy of fuel into electrical energy.Due to its high energy conversion efficiency,outstanding stability and strong sustainability,the world Interest in solid oxide fuel cells(SOFC)has increased dramatically in the past few decades.Nickel-based ceramic materials are widely used as anode materials due to their good chemical stability and electrical conductivity in oxidizing and reducing atmospheres.However,when hydrocarbons are used as fuel,the problems of anode carbon deposition and sulfur poisoning will occur,which will seriously affect the performance of the battery.Symmetrical Solid Oxide Fuel Cells(SSOFCs)is a kind of using the same material as the cathode and anode,which can solve the problem of carbon deposition and sulfur poisoning at the anode by switching the gas path,and also simplifies the battery preparation process.In this paper,two commonly used perovskite oxide materials are used as research objects to explore their applicability as SSOFC symmetric electrode materials.The main contents are as follows:(1)Using citric acid self-propagating method to synthesize Gd0.5Ba0.5FeO3-δ(GBF)and Gd0.5Ba0.5FeNi0.1O3-δ(GBFN)as the research object,proceed from the aspects of phase,electrical performance and electrochemical performance.A systematic study.The results show that:GBF presents cubic perovskite GdBa2Fe3O7.989 structure,GBFN presents cubic perovskite GdBa2Fe3O7.989 structure and orthogonal perovskite GdFeO3 structure and does not react with GDC,and has good chemical compatibility;Excessive doping of Ni at the B site can effectively reduce the polarization resistance.The polarization resistance at 800℃ is reduced from 0.96Ω·cm2 to 0.76Ω·cm2;Excessive doping of Ni at the B site can increase the conductivity of GBF,And have lower activation energy at low temperature,indicating that GBFN has excellent electrocatalytic activity.;The battery performance has been improved to a certain extent.The output power at 700℃ has been increased from 71.81mW/cm2 to 96.88mW/cm2，indicating that GBFN is a very promising cathode candidate material;Observe the cross-sectional morphology of the battery.The electrolyte is sintered densely,the electrode is loose and porous,and the electrode,the transition layer and the electrolyte are in good contact.(2)La0.65Ca0.35FeO3-δ(LCF)and F-La0.65Ca0.35FeO3-δ(LCFF)were synthesized by the self-propagating combustion method of citric acid as the research object,from the aspects of phase,electrical performance and electrochemical performance.Carried out a systematic study.The results show that:LCF and LCFF both present a cubic perovskite structure and do not react with GDC,indicating good chemical compatibility;F-doped LCF can effectively reduce the polarization resistance,at 750℃ The polarization resistance is reduced fromΩ·cm2to 0.48Ω·cm2;F-doped LCFF with halogen elements can effectively improve the conductivity,the maximum conductivity is 285.71 S/cm,and the activation energy at low temperature is less than LCF The activation energy indicates that LCFF has good electrocatalytic activity.The performance of the battery has been improved to a certain extent.The output power at 750℃ has increased from 147.89mW/cm2 to 165.99mW/cm2,indicating that LCFF is a very promising SSOFC cathode material candidate;Observe the cross-sectional morphology of the battery.The electrolyte is sintered densely,the electrode is loose and porous,and the electrode,the transition layer and the electrolyte are in good contact.Figure[15]Table[6]Reference[138]... |
PDF Full Text Request