Preparation And Characterization Of Composite Electrolyte Ce_0.8Re_0.2O_2-?-BaCe_0.8Re_0.2O_3-??Re=Sm,Gd,Y? For Intermediate Temperature Solid Oxide Fule Cell

Solid oxide fuel cell(SOFC)can convert chemical energy of fuel into electrical energy directly and it has attracted much attention due to it's high energy conversion efficiency and environmental friendliness.As the core component of SOFC,the performance of electrolyte directly affects the output power of the cell.The stability of single battery components fell and the cost of materials are higher under high temperature.It is necessary to developing the electrolyte with high conductivity in intermediate temperature conditions can solved these problems very well.In this study,The Ce0.8Sm0.2O1.9-BaCe0.8Sm0.2O2.9(SDC-BCS)composite electrolytes with mole ratio of 1:1 were prepared via one-step citric acide-nitrate gel combustion method and mechanically-mixing method,then composite powders were obtained to study the uniformity of two phase distribution of composite electrolytes SDC-BCS and discuss the effect of phase boundary on the grain boundary conductivity and electrochemical properties;XRD,SEM,conductivity and the single cell electrochemical performance of composite electrolyte SDC-BCS with different composite and different elements doped CeO2 and doped BaCeO3 composite electrolytes were studied.The influence rules of phase composition on the properties of composite electrolytes SDC-BCS and the effect of the doping element on composite electrolytes doped CeO2 and doped BaCeO3 were discussed to obtain composite electrolyte material with excellent electrochemical performance.The research results of composite electrolytes which were prepared by different methods show that the phase distribution of SDC-BCS composite electrolyte via one-step method is more uniform than that of composite electrolyte via mechanically-mixing method.The phase boundary of SDC-BCS composite provides the transfer channel for protons and oxygen ions,which is benefit to the improvement of the grain-boundary conductivity.The more homogeneous the phases distributs,the higher the grain boundary conductivity is.The open circuit voltage and the peak power density of the single cell with SDC-BCS composite electrolyte via one-step method are higher than.that of SDC-BCS composite electrolyte via mechanically-mixing method.The research results of SDC-BCS composite electrolyte prepared by one-step citric acide-nitrate gel method with different composite show that the grain size and the conductivity of composite electrolyte SDC-BCS increases with the increasing of SDC content.The maximum power density of NiO-SDC-BCS|SDC-BCS|LSCF-SDC-BCS single cell based on composite electrolyte with different composite increases with the increasing of SDC content.When the molar ratio of SDC:BCS is 9:1,the maximum power density of single cell is 550mW/cm2,which is 3 times higher than that of NiO-SDC|SDC|LSCF-SDC single cell.The research results of performance on different elements doped CeO2 and BaCeO3 composite electrolytes prepared by one-step citric acide-nitrate gel method with mole ratio of 7:3 show that compared with SDC-BCS composite electrolyte doped by single element Sm,the grain size of SDC-BCY,GDC-BCY,GDC-BCS composite electrolyte are smaller.And the grain size of composite electrolyte GDC-BCY is the smallest.The GDC-BCY composite electrolyte shows the higher grain boundary conductivity and the better electrochemical performance.Under 700? the maximum power density of NiO-GDC-BCY| GDC-BCY |LSCF-GDC-BCY single cell is 458mW/cm2.