Preparation And Doping Modification Of Ni-based Perovskite-like Cathode Materials

Solid oxide fuel cells?SOFCs?have attracted widespread attention due to their high energy conversion rate and environmental friendliness.Three series of Ni-based perovskite like cathode materials were successfully prepared by the EDTA-citric acid route,and their properties were studied.The first series of materials is Pr_1.8La_0.2Ni_0.95-x.95-x Cu_x Al_0.05O_4+??x=0,0.1,0.2,0.3?.With the increasement of Cu doping amount,the electrical conductivity of the samples gradually increases,but their catalytic activity and cell performance increases first and then starts to decrease.Among them,Pr_1.8La_0.2Ni_0.85Cu_0.1Al_0.05O_4+?shows the best performance,but its thermal stability at 700?is very poor.The second series of materials is Pr_2-yLa_yNi_0.85Cu_0.1Al_0.05O_4+??y=0,0.2,0.5,1.0?.With the increasement of La,the average thermal expansion coefficients?TECs?and the thermal stability of the samples increase gradually,but the electrochemical performance decreases gradually.PrLaNi_0.85Cu_0.1Al_0.05O_4+?shows the best performance,but its stability at 800°C is not very ideal.The third series of materials is Pr_4-z-z La_z Ni₃O_10+??z=1,2,3?.As the amount of La doping increases,the average TECs of the samples increase,but the electrochemical performance decreases gradually.In addition,compared with the previous series,the electrical conductivity of this series is significantly larger,but the chemical activity is much reduced.The thermal stability of this series is very good,no decomposition of the materials occurred after calcination at 800°C for 72 h.Among them,Pr₃La₁Ni₃O_10+?has the best performance.The results show that PrLaNi_0.85Cu_0.1Al_0.05O_4+?can be used as the ideal cathode materials for SOFC working at 700°C.When the working temperature is higher,Pr₃La₁Ni₃O_10+?material is a good choice.