Research On Anti-carbon Deposition Mechanism Of Solid Oxide Fuel Cell Based On Biogas Fuel

As an energy device that can directly convert chemical energy into electrical energy,solid oxide fuel cells（SOFCs）have the advantages of high power generation efficiency,low pollution emissions,and a wide range of fuel applications.The direct use of biomass gas such as biogas as SOFCs fuel for power generation is one of the important development trend of SOFCs.However,when using biogas and carbon-containing biomass gas,SOFCs anodes are prone to carbon deposits,resulting in serious degradation of battery performance and limiting their further development and application.This topic aims at the problem that SOFCs anodes are prone to carbon deposits.By optimizing and modifying traditional nickel-yttria stabilized zirconia（Ni-YSZ）anode support SOFCs,the structure and composition of the battery anode and the assembly process on the impact of electricity production efficiency are studied.On the basis of the optimized preparation of the battery,the method of TiO₂ doped anode powder and additional functional layer was used to improve the structure and composition of the battery,and the power generation efficiency and carbon deposition resistance of the modified battery under simulated biogas fuel gas operation conditions were investigated.The mechanism of its anti-carbon deposition behavior studied.In the study of traditional Ni-YSZ anode-supported SOFCs battery,through the optimization of the anode,electrolyte layer and cathode composition of the battery,the highest peak power of the prepared basic battery in hydrogen fuel gas is 592.86 mW/cm².The maximum peak power of this battery in the simulated biogas is only 14.15 mW/cm²,and the system efficiency in the simulated biogas is 2.53%,indicating that the battery cannot operate stably in the simulated biogas.In view of the problem that the basic battery cannot operate well in the simulated biogas,the basic battery was modified.The modification included adding TiO₂ to the anode powder and adding a functional layer containing TiO₂on the anode surface.The performance of the battery doped with TiO₂ in the simulated biogas is better than that of the unmodified battery.The effect of doping with different mass fractions of TiO₂on the battery performance was subsequently tested,and the optimal ratio of doped TiO₂ was obtained.In addition,a functional layer doped with different mass fractions of TiO₂ is further added to the anode surface of the battery to further improve the power generation efficiency.Experiments have found that the power generation performance of the modified battery in hydrogen is similar to the maximum peak power of the basic battery,and its performance in the simulated biogas is better than that of the modified battery without a functional layer.The peak power is 113.38 mW/cm²,the system efficiency is 20.10%.Through the analysis of the micro-morphology,chemical composition,and carbon deposition of the modified battery before and after the test,it was found that the TiO₂ in the anode and the functional layer was reduced to TiO_2-x under high temperature H₂ atmosphere.Combining with the verification of powder high temperature catalysis experiments,it is concluded that one of the reasons why the doped TiO₂ modified battery anode resists carbon deposition may be because under high temperature infrared light and heat radiation,TiO_2-x powder generates electron-hole pairs through excitation and oxidizes surface hydroxyl groups.And water molecules produce hydroxyl radicals with strong oxidizing ability,oxidize the carbon deposits generated on the anode surface during the electricity generation process into CO and CO₂,so as to achieve the purpose of anti-carbon deposition,thereby providing new research ideas for the development of new anti-carbon deposition batteries.