10313

9530

كارشناسي ارشد

ماده چگال

اصفهان: دانشگاه صنعتي اصفهان، دانشكده فيزيك

1393

يازده، 124ص: مصور، جدول، نمودار

ص.ع. به فارسي و انگليسي

هادي سلامتي

مهدي رنجبر

15/4/94

حميده شاكري پور، اسماعيل عبدالحسيني

1396/10/03

كتابنامه

فيزيك

فيزيك

ID9530

125 Optimizing the Solid Oxide Fuel Cell Cathode La0 6Ca0 4Fe0 8Ni0 2 by Microwave Irradiation Nasibeh Ekrami Nejad n ekraminjad@ph iut ac ir March 2015 Department of Physics Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Prof Hadi Salamati salamati@cc iut ac irAssistant Dr Mehdi Ranjbar ranjbar@cc iut ac irAbstractA fuel cell is an electrochemical device that directly converts chemical energy of a fuel to electrical energy All fuel cells consist of two electrodes anode and cathode and an electrolyte Lack of direct combustionleads to higher efficiency than Carnot heat engines and also reduced environmental impact Solid OxideFuel Cells are a class of fuel cells characterized by the use of a solid oxide material as electrolyte Advantages of this class of fuel cells are high efficiency long term stability fuel flexibility low emissions and relatively low cost of operation The biggest disadvantage is high operating temperature which resultsin longer start up times and mechanical and chemical compatibility issues Much of the efforts today focuson reducing the operating temperature without loss of its performance One way to overcome this issue isto improve the structural and functional characteristics of available cathodes Among the different methods available for processing a ceramic the use of microwaves as energy sourcefor synthesis and sintering of ceramics has gained substantial attention among scientists due to its uniqueadvantages namely shorter processing times and superior quality of the products obtained thereafter In this investigation La based perovskite oxide cathode La 0 6Ca0 4Fe0 8Ni0 2O3 was used because of its goodelectron and ion conductivity chemical stability and satisfactory catalytic activity Sol gel method was usedto synthesize La0 6Ca0 4Fe0 8Ni0 2O3 XRD analysis revealed that microwave results in a much bettercrystallization Electrical resistance measurement versus temperature of microwave assisted synthesizedsamples reveals that dual conductivity occur in a lower temperature which attribute to better crystallizationand less oxygen content This leads to increase of active layer between the electrolyte and cathode thatresults better performance Small polaron hopping was responsible mechanism in conductivity Electericalrelaxation technique revealed that less activation energy achieved for microwave treatment of samples Calculated ionic diffusion and surface exchange coefficients by using electrical relaxation technique revealed that microwave results in fast oxygen reductin Scanning electron microscope used to study the topography of the particles It reveals that microwaveassisted synthesis results in smaller particles size Electrochemical impedance measurement used todistingusihing the portion of grain and grain boundry in electerical resistance In the end an anode supported cell have been made by using pulse laser deposition technique Keywords Solid Oxide Fuel Cell Cathode Sol gel Microwave Irradiation Electrical Conductivity

هادي سلامتي

مهدي رنجبر

حميده شاكري پور، اسماعيل عبدالحسيني