| As a new type of energy conversion device,solid oxide fuel cell（SOFC）can directly convert chemical energy into electrical energy.The operating temperature of SOFC is high,and it can directly use hydrocarbon fuel and other biomass fuel for electrochemical reaction.For SOFC,when the hydrocarbon fuel is used directly as the working fuel,the carbon deposition phenomenon will seriously break the morphology of the anode,causing its electrochemical performance to decrease sharply in a short time.Therefore,high-performance anti-coking anode materials are the key to SOFC research.At present,the commonly used Ni ceramic-based anode materials are prone to carbon deposition when working in hydrocarbon fuels for a long time,which causes the anode structure to be severely broken and the electrochemical performance of the cell to be deteriorated.Perovskite BaCeO3 has excellent water absorption properties and can effectively suppress carbon deposition.However,its oxygen ions and electron conductivity are insufficient,which limits its electrochemical performance.Therefore,this paper is based on BaCeO3 to study new anode materials.Ba Ce0.9Y0.1O3-δ（BCY）is prepared by doping Y into the BaCeO3 lattice to increase its oxygen vacancy concentration and ionic conductivity;and then doping Ni to the BCY lattice to prepare Ba(Ce0.9Y0.1)0.8Ni0.2O3-δ（BCYN）,the reduction of metal Ni particles from the BCYN lattice in situ,can not only improve its catalytic activity and electronic conductivity,but also ensure that it has good resistance to carbon deposition.The main research contents and conclusions of this paper are as follows:（1）BCYN powder and BCYN impregnating solution powder were prepared by the sol-gel method.After XRD analysis,it was confirmed that all phases had formed;and after the reduction reaction,Ni diffraction peaks appeared in the phases.The XPS test and TEM test were performed on the impregnating solution powder,and it was found that Ni atoms in BCYN were exsolved from the matrix lattice after reduction by hydrogen.Co-fired BCYN and Gd0.1Ce0.9O1.95（GDC）powders have no heterogeneous phase,which proves that these two materials have good chemical compatibility.（2）The mechanically mixed BCYN+GDC composite anode material was studied,and it was found that the Ni nanoparticles exsolved on the surface can also significantly improve its electrochemical performance.The polarization resistance of the Ni-BCYN+GDC anode at750°C in H2 and CH4 atmospheres is 0.0042 and 0.0054Ω·cm2,respectively,showing extremely excellent electrochemical activity.In the CH4 atmosphere,the power density after reduction is much higher than that of the cell without reduction anode.（3）The BCYN/GDC composite anode material prepared by impregnating BCYN into the GDC skeleton was studied,and its performance was characterized.EIS tests were performed on full cells under different impregnation times.It was found that the full cell impregnated twice in BCYN at 750°C had the lowest polarization impedance.At 750°C,the peak output power of the full-cell impregnation in H2 and CH4 atmospheres was 270 and 211 m W·cm-2respectively.（4）The long-term performance tests in CH4 atmosphere were performed on full cells with mechanically mixed BCYN+GDC and BCYN/GDC prepared as impregnation methods as anodes.The former was tested under open circuit for 36 h,while the latter was tested under constant current discharge for 100 h.The test results show that the performance of the two types of full cells is basically stable.The anodes after long-term testing were analyzed by Raman test and morphological characterization.It was found that the anode structure of both materials was very stable and had good resistance to carbon deposition. |
