Study On The Praparation And Modification Of Ni-based Anodes For Intermediate Solid Oxide Fuel Cells Using H₂ And CO As Fuel

Solid oxide fuel cells?SOFCs?have attracted considerable attention as an electrical power generating system in a friendly way primarily due to their high efficiency,low pollution and fuel flexibility.H₂/CO mixture gas is the main reactive gas in the anode chamber.Therefore,it is necessary to study the effect of H₂/CO ratio composition on anode performance.NiO-YSZ anode has been commonly used and extensively studied as one of the anode materials for SOFCs,coarsening of the Ni particle and carbon deposition at high temperature may affect the overall electrical conductivity of anode,and probably also lead to decrease electrochemical performance of SOFCs.Therefore,the Ni-based anode is selected for modification study.The preparation process of Ni-YSZ/SSZ/LSM electrolyte-supported SOFC was explored in detail.Performance of Ni-YSZ/SSZ/LSM electrolyte-supported SOFC using H₂ and CO as fuels under different conditions was tested.Later,single cells with a series of bimetal Ni_1-xFe_xO-YSZ/Ni_1-xCu_x-YSZ and trimetal Ni_0.9Cu_0.1-xMg_x-YSZ anode were prepared and investigated at intermediate temperature.It has certain reference value for realizing the commercial production of SOFCs.The main context include three aspects:?1?The process to prepare SSZ electrolyte was tape casting process,and coated electrode material by screen printing.The optimal preparation process of Ni-YSZ anode was,NiO/YSZ?mass%?was 6:4,nano NiO/Micron NiO particles?mass%?was 1/1,the pore former/active substance?mass%?was 3/20,and the calcination temperature was1350°C,The anode with no cracks smooth surface and uniform porous structure can be obtained.?2?The performance of Ni-YSZ/SSZ/LSM electrolyte-supported SOFC using H₂ and CO as fuels under different conditions is tested.The experiment results show that,?1?The performance of SOFC increases with the rise of temperature and the flowing Anode gas,decreases with the rise of N₂ concentration.?2?the maximum power density and optimum long-term stability and carbon deposition resistance of SOFC at H₂/CO ratio of 3/1.Comprehensive consideration of factors such as discharge performance,economic cost,ease of operation,safety,etc.the optimum condition:Operating temperature at 800?,the flowing anode gas was 250mL/min,20%N₂ concentration,H₂/CO ratio was 3/1.?3?The bimetal Ni_1-xFe_xO-YSZ/Ni_1-xCu_x-YSZ?x=0.05,0.1,0.15,0.2?and Trimetal Ni_0.9Cu_0.1-xMg_x-YSZ?x=0.05,0.1,0.15,0.2?anode were prepared and investigated.Microstructure and performance were tested,experiment results show that:After doping Fe/Cu/Mg to Ni-YSZ anode material,XRD shows the Metal oxidation phase which is face-centered cubic?FCC?structure,coarsening of the anode crystal grains was effectively suppressed,without obvious adverse effect on the thermal expansion property of anode material,the electrical conductivity of the material and the power generation performance for SOFC were effectively improved.Long-term stability and carbon deposition resistance were also improved.It is concluded that the electrochemical performance of Ni_0.9Cu_0.1-YSZ composite anode is the best through the above studies,attached maximum power density as 310.1mW/cm².