Font Size: a A A

Research On New Perovskite Anode Materials For Direct Carbon Solid Oxide Fuel Cell

Posted on:2024-06-14Degree:MasterType:Thesis
Country:ChinaCandidate:X ChenFull Text:PDF
GTID:2531307112955579Subject:Materials Physics and Chemistry
Abstract/Summary:PDF Full Text Request
Up to date,new energy technologies have been energetically developed to tackle the long-standing issues of environmental pollution and energy crisis,yet the coal fuel in China still dominates in the energy structure and its status is unshaken.Direct carbon solid oxide fuel cell(DC-SOFC),as a new high-efficiency and clean coal power generation technology,is strategically significant for the revolution of traditional coal-fired power generation technology and the realization of the dual-carbon goal.Since the anode is the main reaction site of DC-SOFCs,the development of anode materials with high catalytic activity,stability,and resistance to carbon deposition has become the research focus in the DC-SOFC field.As an excellent electron-ion mixed conductor,perovskite materials are favored by researchers due to their good electrocatalytic activity,structure regulation,stability and high resistance to carbon deposition and sulfur poison.This thesis focuses on the investigation of perovskite anode materials with high catalytic activity for direct carbon solid oxide fuel cells,and has successfully developed vanadium doped single perovskite anode materials and layered perovskite anode materials in-situ exsolution of alloy nanoparticles.Firstly,a single perovskite anode material,La0.5Sr0.5Fe1-xVxO3-δ(LSFVx)was designed and prepared.After doping with V element,continuous electron conduction channels and more oxygen vacancies are formed inside LSFVx,which are conducive to electron transfer and oxygen ion diffusion,enabling the anode material to exhibit excellent electrocatalytic activity on the electrochemical oxidation process of carbon fuel.At the same time,it is determined that the optimal doping amount of V is 0.1.At 850℃,the maximum power density and polarization resistance of DC-SOFC with LSFV0.1 anode operated on brown coal char fuel are 249 m W cm-2 and 0.37Ωcm2,respectively,along with the longest discharge time of 8.65 h,and the highest fuel utilization of 38.76%,which is significantly better than that of pure LSFO3-δanode material(170 m W cm-2).In addition,excessive vanadium doping(LSFV0.15)will decrease the concentration of oxygen vacancies,hindering the gas adsorption and diffusion process,which will lead to the deterioration of the electrochemical performance of the DC-SOFC.The SEM and XRD results after the cell stability tests show that the LSFVxperovskite anode materials have great structural and redox stability.Then,in order to further improve the electrochemical performance of DC-SOFC,(Pr0.4Sr0.6)3(Fe0.85Nb0.15)2O7 layered perovskites with in-situ exsolution alloy particles were engineered and fabricated as DC-SOFC anode materials.A fluffy and porous cubic perovskite structure material(P-PSMFN,M=Co,Ni)was synthesized by combustion method.Through a one-step thermal reduction method,the P-PSMFN(M=Co,Ni)anode materials undergo an in situ self-assembly process,transforming the cubic perovskite structure into a layered perovskite structure,RP-PSMFN(M=Co,Ni).And the nano-alloy particles were in situ exsolved on the surface,which show high electrocatalytic activity for the oxidation of carbon on the anode side and good electrochemical performance of the DC-SOFCs.Moreover,the LSGM electrolyte material matching the layered perovskite anode was prepared by a solid-state method.The LSGM electrolyte material has excellent oxygen ion conductivity and a dense internal microstructure.Then,DC-SOFCs with the configuration of RP-PSMFN(M=Co,Ni)|LDC|LSGM|Ag-GDC were assembled.The results show that performance of the RP-PSCFN with Co Fe alloy anode is comparable to the one of RP-PSNFN with Ni Fe alloy anode,with maximum power density and polarization resistance of281 m W cm-2 versus 284 m W cm-2,and 0.34Ωcm2 versus 0.32Ωcm2,respectively.The cell with RP-PSCFN anode runs stably for up to 13 h,and fuel utilization of the brown coal char is up to 58.21%.Compared with traditional Ag-GDC anode,in situ exsolved Co Fe alloy and Ni Fe nanoalloy particles show superior electrocatalytic activity,which could remarkably enhance the electrochemical performance of the cell.
Keywords/Search Tags:Solid oxide fuel cell, Carbon fuel, Perovskite anode, In situ exsolution, Alloy particles
PDF Full Text Request
Related items