| Solid oxide fuel cells(SOFCs)is a kind of energy converse device that possess some advantages such as full solid structure,using hydro-carbon gas as fuel,high conversion rates,and has gained espacially conserns in many kinds of new energy equipments.It has already been commercially used as a part of distributed power station.However,operation at high temperature brought some difficulties,that is quickly aging for the equipment,sealing difficulty,and so on.Besides that,as using hydro-carbon fuel gas,the carbon deposition/coaking as well as sulfur poisoning problem at anode has been introduced.Other problems such as CO2 poisoning at cathode brought by using ambient air,and so on.SOFCs has already come to the practical stage,not only the optimization of one single kind of materials,but also the cooperaton among anode,cathode and electrolyte is necessary,that is the key issue of SOFCs whole device optimization designing.This work has do some systemic research on the comprehensive properties and compositions designing rules of three main series of key materials.The results was indicated that metal oxides are most popular anode catalytic series by big data statistics,based on first principle calculation,the status of metal elements in the anodic working conditions(such as high temperature,strongly reducing atomsphere)has also been analyzed,as well as the relationship with certain key properties,according to experiment data,the optimizing region,centralized at NiO-CoO,has been desided,and the intrinsic reason was found out based on thoery calculation that band gap and bulk modulus are in a moderate to low region;SrBO3 series perovskite materials can be used as electrode for SOFCs,also earned a lot of concerns,the influnce on structure stability by elements may be used in B site is valuable to research.Based on comparison of total energy that calculated by first principle method,and on big experiment data analyzing,the three regions,centralized at Mo-Fe-Co,of B site elements composition optimization has been decided,theoratical consequences also showed that the difference of electronic performance,low vacancy formation energy,low ion migration energy and small band gap,is the reason of optimizing region formed;Rules of "gene" in different structure electrolytes has been researched,the relationship between band gap and stability has been analyzed by big data,and the electronic structure and oxide ion migrating energy has been calculated by first principle method,based on that,the relationship between electronic structure and oxide ion migrating ability has been analyzed,according to the two relationships above,the relative tendency of stability and key performance of five electrolytes,CeO2,ZrO2,(La,Sr)(Ga,Mg)O3,etc,with different structure and composition was obtained,and the inner reason has been discussed.Besides that,different atoms' arrangement in LaSrCoO4 and PrBaMn2O5,which are high performance cathode for SOFC,and its impact on oxide ion transportation has been researched.Based on the initiatory researches on rules of materials obtained by different mode for different materials all above,we can summarize that:the stability and power of SOFCs restrict and condition each other,basical mode for whole optimization is investigation on relationship between materials stability and comprehensive performance,these three rules of materials we obtained are reflect of the essence in today's abondant material research experience for SOFCs.According to these rules,the essencial principles for SOFCs' whole optimization was discussed,and also proposed a new practical way of theoratical thinking for the research on SOFCs' key materials. |
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