Research On Component Modification Of Solid Oxide Fuel Cells Based On Cation Regulation Strategy

Solid oxide fuel cell（SOFC）with high energy conversion efficiency,fuel adaptability,high waste heat utilization,environment friendly is a major concern.At present,the generally high operating temperature（800～1000℃）will increase the indirect preparation cost and shorten the service life of the battery.If it does not affect the battery power output in order to reduce its working temperature,it is necessary to reduce the electrode polarization resistance and electrolyte ohm impedance.SOFC cathode on the surface of the oxygen reduction reaction is more difficult than the anode surface oxidation of fuel,energy loss is bigger,the development of high performance cathode materials under low temperature is the research focus in the SOFC cathode.The higher the sintering temperature,the electrolyte is more dense,ohm impedance is lower,but the high sintering temperature electrolyte damage probability is also increased dramatically,by optimizing the electrolyte composition,in does not affect the sintering performance under the premise of reduce the sintering temperature is one of the main methods of SOFC electrolyte modification research.This topic has carried out the following research work:We investigated the effect of La and Sr defects at A site on the electrocatalytic activity of LSCF.The defect quantity of La and Sr content selection is 0.05,and we prepare a kind of:（LS）_0.95CF.Through testing and characterization,it is found that（LS）_0.95CF has more oxygen holes in the cathode series,and it has stronger ion conduction and oxygen transmission ability when applied in the cathode of the battery.The electrode impedance of the symmetric cell prepared with（LS）_0.95CF as the cathode at different temperatures is greatly reduced compared with that of the LSCF electrode.Anode support type single cell(Ni-SDC||SDC||（LS）_0.95CF)in the output power of 650°C to 212 m W cm^-2,the defect of the La and Sr can improve the ability of electrode oxygen reduction reaction.By doping metal elements（Ni,Cu,Co,Fe）to modification of SDC electrolyte,low sintering temperature,the preparation of metal doped SDC electrolyte on the electrochemical impedance,phase structure,shrinkage rate,ionic conductivity and microstructure were characterized,and compared with blank SDC electrolyte analysis,the results show that the lower calcination temperature of SDC series of metal doped with basic phase perovskite structure,the conductivity increased,preparation of symmetric cell electrochemical performance tests show that under the proper doping content,electrolyte with Ni,Co,Fe and other metal can to a certain extent,reduce the electrochemical impedance,improve the electrochemical performance.The preparation of SOFC single battery is based on the doping metal electrolytes with lower calcination temperature.We explore the effect of types and content of metal doping to the battery output capability The experimental results show that different metal doping batteries performance have the difference,but if the metal element is under the proper doping content,the performance of single battery can be improved.It shows out that introducing metallic elements such as Ni,Cu,Co,Fe into the electrolyte can be one of an optimization method to improve the performance of SOFC.