Microwave Synthesis And Characterizations Of Powder As New Cathode For ITSOFC

Intermediate temperature solid oxide fuel cell （ITSOFC） have a higher energyconversion efficiency（it can be achieved80⁹0%）, lower operating temperature,longer service life, widely available fuel,small pollution to the environment, and so on,So the ITSOFC is called a new clean and green energy sources in21century. But thetraditional raw materials, the purity rare earth and the rare earth nitrate, have a highcost for SOFC preparation, therefore seeks for the low price, the perform reliablycathode material will become the hot points of the ITSOFC present research.Based on the lower prices for raw materials mixed rare earth oxide materials, andfurther conducted its alkaline earth metal ions Sr²⁺, Ca²⁺doping, and used themicrowave sintering method and solid phase synthesis method of the Ln-B-Co-O（Ln=mixed rare earth, B=Sr, Ca） of the cathode material preparation. With a view tolowering the cost of raw materials, and on the better basis to meet the ITSOFCcathode material performance requirements, and to the preliminary study of the batteryperformance. In addition, the paper also mixed rare earth oxides and added suitableSamarium oxide, prepared by partly coprecipitation of the Ln-B-Co-O-Ce_0.8Sm_0.2O_1.9（Ln-B-Co-O-SDC） of the composite cathode materials, and the reaction process,structure and the electrical properties of a preliminary study.The conclusions show that: solid phase synthesis of Ln-B-Co-O cathode materialsintered at1200℃and4h after Microwave Sintering of Ln-B-Co-O cathode materialsintered at1200℃after30min, and not of the product formation of a singleperovskite structure, but CeO₂cubic fluorite phase and perovskite phase coexistence,common at this time of the alkaline-earth metal ion doping Ca²⁺, Sr²⁺enter LaCoO3crystal lattice formation of solid solution; In the same time, The carbonate of powdersdecomposited its oxides at the range of700⁹50℃, during the action process Sr²⁺ionunited with the CeO₂of mixed rare earth easy and become perovskite phase, Ca²⁺ionsubstitute La2O3easier. Compared to Ln-Sr-Co-O, Ln-Ca-Co-O’s electricalconductivity increased, the activation energy of electrical conductivity decreased; In the room temperature to800℃, Ln-B-Co-O cathode material changes in theconductivity of the p-type insulation pore small polaron theory, Sr²⁺ion doped slightlylower than the conductivity of doped Ca²⁺ions, but in the500to800℃Ln-B-Co-Oconductivity are more than100S/cm; at the same time with the temperature in the newelectrolyte Ce_0.8Sm_0.2O_1.9has good compatibility, performance of a good adaptation.By coprecipitation1100℃sintering4h synthesis of Ln-B-Co-O-SDC compositecathode of the material, its system of CeO₂cubic fluorite phase to the main phase andwith the perovskite phase coexistence in the samples500⁸00℃, conductivity greaterthan100S/cm to meet the ITSOFC of the electrical properties of the cathode materialrequirements.