| High temperature will not only cause too much waste heat to the fuel cell,but also make its internal structure change,reduce performance and efficiency.Therefore,reducing the operating temperature of fuel cells,and research and development in the low temperature can have good electrical properties of the electrode material,has become the current stage of further development of SOFC imperative.At present,the working temperature down to the temperature(500-800?)is the development trend of SOFC.In recent decades,scholars around the world have invested a lot of manpower,material and financial resources to solve or replace fossil fuels,so fuel cell technology came into being and has made great progress.One of the molding method because of its simple operation,low production costs,has become one of the hot research at this stage.The preparation process of a single cell has an effect on its performance,but there is no further research on this aspect.Therefore,the study of the preparation process of the single cell to determine the optimal process parameters of the single cell will be the future of low-temperature solid oxide fuel cell research in the future,will be the future of low-temperature solid oxide fuel cell research data reference,Can further accelerate the practical process of low temperature fuel cell,has important academic value.This paper is based on this point,the SOFC electrode materials and single cell preparation process in-depth exploration and research.In this paper,La0.7Sr0.15Ca0.15Co0.4Fe0.6O3-? cathode materials were synthesized by citric acid method and reverse coprecipitation method,and their electrical conductivity were measured with the temperature change.Then,(NiO-SDC|SDC-carbonate|LCSSF-SDC)and tested for electrical properties.The results show that the average particle size of the obtained powders is 16.5 and 19.7 nm respectively.When the temperature rises to about 650? the electrical conductivity of the two cathodes is 770,550 s·cm-1,Indicating that the smaller the average particle size of the cathode powder,the electrode reaction area will increase,the corresponding cathode material conductivity will be greater.Therefore,the citric acid method prepared by the cathode material is better than the reverse coprecipitation method.The La0.7Sr0.15Ca0.15Co0.4Fe0.6O3-? prepared by citric acid method is the cathode material,NiO-SDC(samarium doped cerium oxide)is used as anode and SDC-carbonate as compound electrolyte.In different process And then the theoretical and data analysis was carried out in several aspects,such as molding pressure,sintering temperature,sintering time,hydrogen flow rate,and so on.The results showed that the single cell was prepared by the method of molding.The best process parameters provide the theoretical and data support for the best process parameters obtained in this experiment.The results are as follows:when the mass ratio of anode material,electrolyte material and cathode material is 4:1:2,pressure:17 MPa,sintering temperature:700?,sintering time is 4 h,hydrogen flow rate:110 ml/min The best performance,single cell open circuit voltage to reach the maximum,the maximum value of 1.02V.Finally,the cathode material was prepared by citric acid method combined with the best process parameters assembled into a single cell,and its impedance was tested to obtain the total resistance of the single cell at different temperatures,ohmic resistance,polarization resistance,the resistance with the temperature And the minimum resistance at 700?:total resistance 0.256 ?,ohmic resistance 0.145 ?,polarization resistance 0.111 ?.The experimental work will provide a reference for the development of low temperature fuel cell,with strong theoretical and experimental reference value. |
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