Doping Of Perovskite-like Cathode Materials

The solid oxide fuel cell?SOFC?has shown well prospects due to cleanliness and high efficiency.However,there are many practical problems caused by the high operation temperature.So,exploring cathode materials that can perform well in low and medium temperature environments is the research focus of this field.From the currently literatures,there are few studies on the Sr doping of the A site of Ln₂NiO4+?materials,which lead to the electrochemical performance of the materials are different.In addition,studies have shown that doping A or B sites can optimize its performance.Therefore,in order to appreciably evaluate the effect of Sr doping on material properties and further improve it properties.In this paper,the series of the materials La_2-xSr_xNiO₄+??x=0-1.5??LaSrNi_0.8M_0.2O₄+??M=Ni,Cu,Co,Fe??Nd_1.5Pr_0.5Ni_1-xM_xO₄+??M=Cu,Co,Mo;x=0-0.1??La₄Ni_3-xCu_xO₁₀+??x=0-0.7?were successfully prepared by sol-gel method and to obtain cathode materials with excellent electrical properties.The phase structure,electrical conductivity,thermal expansion coefficient?TEC?,catalytic performance,and single cell output power of La_2-xSr_xNi O₄+?series materials were characterized and analyzed.The results show that the TEC decreases first and then increases,the conductivity first increases and then decreases,and the area-specific resistance?ASR?value first decreases and then increases slightly,and the output power of the single cell decreases first and then increases with the increase of the doping content of Sr.When the amount of Sr is less than 1.5,the catalytic performance of the material can not be improved,but the conductivity of the material can be greatly improved.As for Sr doped materials,the LaSrNiO₄+?material have the better electrical properties.The phase structure,thermal matching and electrical properties of LaSr Ni_0.8M_0.2O₄+?series materials were explored.The results show that the conductivity and the ASR values of the materials are reduced differently,the output power of the materials increased by the doping of Cu or Co;the Co could increases the TEC,while the Fe decreases it.Comprehensively,the Cu or Co can improve the electrical properties of cathode materials.The effects of Pr,Cu,Co,Mo on the A and B site composite substitution on the phase structure,thermal matching,and electrical properties of Nd₂NiO₄+?materials were investigated.The results show that A and B site doping has a synergistic effect and the Cu doping improved the conductivity,while reduced the ASR value and TEC;The Co or Mo doping reduced the conductivity,increased the ASR value.The ASR value of 10 mol%Cu at 800?is 0.032?cm².Therefore,the doping of Cu can slightly improve the electrical properties of the material.The effects of increasing the doping amount of Cu on the phase structure,thermal matching and electrical properties of higher-order La₄Ni_3-xCu_x O₁₀+?series materials were studied.The results show that the electrical conductivity first increases and then decreases,and the ASR value decreases first and then increases with the doping amount of Cu increase.The La₄Ni_2.5Cu_0.5O₁₀+?material has the best comprehensive performance,with a peak power density of 379 mW cm^-2 at 800?.