Study On Cathode Materials Of Pr₂NiO_4+? Based Medium Temperature Solid Oxide Fuel Cell

In order to solve the problem of energy shortage and environmental pollution that China is facing and to achieve sustainable social development,China needs to find sustainable energy to meet the needs of human production and life.Fuel cells are an excellent candidate for sustainable energy development because of their efficiency,safety and cleanliness.Among them,solid oxide fuel cell?SOFC?has attracted wide attention from many researchers because of its high efficiency,high reliability and excellent environmental benefits.However,SOFC's operating temperature is often as high as 1000°C,and its supporting equipment and materials are more demanding,hindering its commercial application.Therefore,the development of medium temperature SOFC with operating temperature of 600?800°C has important engineering significance.The development and optimization of SOFC cathode materials,anode materials and electrolytes is an effective way to reduce the operating temperature of SOFC.A large number of literatures show that,as a new type of medium temperature SOFC cathode material,the oxide material of K₂Ni O4+?structure has better oxygen ion diffusion performance,oxygen surface exchange performance and mixed ion electron conduction performance than traditional oxide materials.Therefore,it has become a research hotspot in this field.Among the cathode materials of this type,Pr₂Nioxides are particularly prominent.In this paper,based on the development requirements of medium temperature SOFC,based on Pr₂Nioxide,the feasibility of the system as a SOFC cathode was systematically tested by doping modification,compounding,material characterization,battery assembly and single cell power generation performance test.Experimental study.The experimental results are as follows:The material of Pr₂Ni_1-xCu_xO4+??x=0.1,0.2,0.3,0.4?was synthesized by high temperature solid state reaction method.The material exhibits good chemical compatibility with the solid electrolyte LSGM under high temperature conditions.The thermal expansion coefficient of this materials is close to that of LSGM electrolyte.The electrochemical performance of cells with the synthesized cathodes were measured and compared by testing single cells at 850°C.The results show that when the single cell using Pr₂Ni_0.7Cu_0.3O4+?as the cathode,it shows a lower polarization resistance that of7.87?·cm^-2,peak power density is 478 m W·cm^-2.In order to further improve the performance of the electrode material and increase the oxygen vacancy concentration of the cathode material,the Pr₂Ni O4+?oxide is co-doped with Cu and Fe.In this paper,Pr₂Ni_0.9-xCu_xFe_0.1O4+??x=0.1,0.2,0.3,0.4?materials were synthesized by high temperature solid state reaction method.The thermal expansion coefficients and electrochemical properties of Cu and Fe co-doped materials were studied.The results show that the electrochemical properties of the cathode material after co-doping have been improved.At the operating temperature of 850°C,the Pr₂Ni_0.6Cu_0.3Fe_0.1O4+?cathode material has a minimum polarization resistance of 3.75?·cm^-2.The peak power density is 595 m W·cm^-2.