Prepration And Electrochemical Performance Of SrCo_1-xTa_xO_3-? Cathode And Its Composite Cathode With Pr₆O₁₁

Solid oxide fuel cell?SOFC?is a power plant that converts chemical energy directly into electricity,with its high efficiency,low pollution,low cost and other characteristics have received attention.The cathode material is one of the important components of SOFC,which can increase the triple phase boundary?TPB?of oxygen reduction and improve the catalytic activity of the electrode,the development of cathode with high catalytic activity to improve the output performance of SOFC is a goal having been pursuing.In this paper,a Ta-doped SrCo_1-xTa_xO_3-??SCTO?cathode material was prepared and its electrochemical performance were researched.To further promote the electrocatalytic activity of the SCTO cathode.The composite cathode material SCTO-Pr6O11 with the Pr₆O₁₁ composition was prepared,and the electrochemical performance of the composite cathode materials and the effect of Pr6O11 on the cathode properties were also studied.In this paper,the solid phase method was used to prepare SrCo_1-xTa_xO_3-??x=0-0.3?cathode materials.The results show that,after the SrCo_1-xTa_xO_3-?cathode powder is sintered at 1100°C for 10 hours,a single phase cubic perovskite structure has formed,and with the increase of Ta doping,the volume of the cell slowly increased.When the Ta doping amount x=0.1 and 1050°C sintered for 4h,the semi-cell polarization impedance?R_p?is minimal,at 800°C,R_p is approximately0.0499?·cm²,the impedance of the single cell supported by the electrolyte at800°C is 0.2704?·cm²,the maximum power density is 259.34 mW/cm².In order to further improve the catalytic activity of SrCo_0.9Ta_0.1O_3-??SCTO?cathode,SCTO-PO composite cathode material was prepared by combining with Pr₆O₁₁?PO?using mechanical mixing method and ion impregnation method respectively,preparation of.The results show that,when the SCTO-PO composite by mechanical mixing method was sintered at 850°C for 2 hours,there was no chemical reaction between SrCo_0.9Ta_0.1O_3-?and Pr₆O₁₁,indicating that there was a good chemical compatibility between SrCo_0.9Ta_0.1O_3-?and Pr₆O₁₁.Moreover,when the Pr₆O₁₁ content is 30%,the R_p of the SCTO-PO composite cathode is the smallest,it is about 0.2061?·cm² at 800°C,the output power of the single cell supported by SDC electrolyte is 440.65 mW/cm²;while the composite cathode of SCTO-PO prepared by ion immersion method has better electrochemical properties.The corresponding content of the cathode of Pr₆O₁₁,its R_p value is only 0.0113?·cm²,its single cell output power is as high as 719.285 mW/cm².This is much greater than the performance of single phase cathode SrCo_0.9Ta_0.1O_3-??R_p is 0.4373?·cm²,single cell output power is 259.34 mW/cm²?,this shows that the SCTO-PO composite material is a kind of cathode material with great potential.