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Optimization Of The Performance Of (Pr 0.9 La 0.1 ) 2 (Ni 0.74 Cu 0.21 Ga 0.05 )O 4+? Electrode

Posted on:2018-06-24Degree:MasterType:Thesis
Country:ChinaCandidate:S ShengFull Text:PDF
GTID:2351330515978853Subject:Inorganic Chemistry
Abstract/Summary:PDF Full Text Request
Compared with the traditional oxide cathode,oxides?A2BO4?with K2NiF4 structure exhibit excellent oxygen ion diffusion and conductivity,and thermal compatibility with the commonly used electrolyte materials.Thus,as new kinds of IT-SOFC cathode materials,these materials cause the great attention of researchers.Among the A2BO4 oxides,Pr2NiO4-based materials become excellent potential IT-SOFC cathode materials,due to their high electrocatalytic activity.In this thesis,the properties optimization of(Pr0.9La0.1)2?Ni0.74Cu0.21Ga0.05?O4+??PLNCG?have been studied.The main results are as follows:The PLNCG oxide powders were synthesized by EDTA-citrate method,and the composite cathode with Ce0.9Gd0.1O1.95?CGO?powder was prepared.The electrochemical results show that the addition of CGO powders into PLNCG electrode was effective in increasing the oxygen reduction reaction sites and improving the electrode performance.The addition of 30wt%CGO in cathode resulted in the lowest polarization resistance of 0.092 ?.cm2 at 700?.The rate limiting step of the composite cathode is charge transfer process.The maximum power density of anode-support single cell?Ni-CGO/CGO/PLNCG-30%CGO?reaches 569 mWcm-2 at 700?.The PLNCG porous cathode was prepared by pore-forming agent polystyrene microspheres?PS?.The results showed that the addition of 10wt%PS into PLNCG electrode was effective in improving the electrode performance.The polarization resistance is 0.144 ?cm2,which decreases 28%than that of the cathode without PS at 700 ?.The oxygen partial pressure dependence of RP indicates that the rate limiting step of the porous cathode is charge transfer process.The maximum power density of CGO electrolyte-support single cell reaches 220 mWcm-2 at 700?.The PLNCG and PLNCG-CGO nanofibers were synthesized by electrospinning method.And then use them to build three-dimensional network structure of the cathode.The polarization resistance of nanofiber cathode is 0.134 ?cm2,which decreases 32%than that of the powder cathode.The addition of 10wt%CGO in nanofiber cathode resulted in the lowest polarization resistance of 0.08 ?.cm2 at 700?.The oxygen partial pressure dependence of RP indicates that the rate limiting step of the nanafiber cathode is charge transfer process.The maximum power density of CGO electrolyte-support single cells,Which cathodes were PLNCG and PLNCG-CGO nanafiber,reached 231 mWcm-2 and 253 mWcm-2 at 700?,respectively.
Keywords/Search Tags:IT-SOFC cathode material, composite cathode, porous cathode, nanofiber cathode, electrochemical properties
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