發(fā)布時(shí)間：2018-03-20 01:22

  本文選題：固體氧化物燃料電池　切入點(diǎn)：離子浸漬法　出處：《合肥工業(yè)大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：固體氧化物燃料電池(Solid Oxide Fuel Cell,SOFC)因具有能量轉(zhuǎn)換效率高、燃料可選范圍廣,環(huán)境友好等優(yōu)點(diǎn)而受到廣泛關(guān)注。實(shí)現(xiàn)SOFC的產(chǎn)業(yè)化發(fā)展,關(guān)鍵是降低其工作溫度和成本。但是,隨著溫度的降低,陰極的極化電阻增加,導(dǎo)致電池性能降低。因此,高性能陰極材料的研發(fā)是當(dāng)前SOFC領(lǐng)域研究的熱點(diǎn)之一。在陰極材料中添加適量的催化材料或者電解質(zhì)材料制備復(fù)合陰極,可以有效提高陰極表面的氧化還原反應(yīng)(ORR)過(guò)程,從而降低陰極的極化電阻。離子浸漬法是一種新穎的SOFC多孔復(fù)合電極制備技術(shù)。該技術(shù)通常先將陰極制成多孔骨架,然后將含電極活性材料的液相在毛細(xì)管力的驅(qū)動(dòng)下滲入此多孔骨架中,前驅(qū)體經(jīng)低溫?zé)岱纸馍上鄳?yīng)的氧化物,從而實(shí)現(xiàn)電極活性材料相和陰極骨架的復(fù)合。該工藝制得的電極催化活性高、低溫性能好,是提高SOFC性能,降低其工作溫度的一個(gè)重要途徑。本論文第二章通過(guò)水熱法在多孔La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ)-Sm_(0.2)Ce_(0.8)O_(1.9)(LSCF-SDC)復(fù)合陰極表面負(fù)載Co_3O_4催化劑,并對(duì)改性前后樣品的物相結(jié)構(gòu),顯微組織,電化學(xué)性能及其單電池的功率密度進(jìn)行測(cè)試。實(shí)驗(yàn)結(jié)果表明,對(duì)LSCF-SDC陰極浸漬Co(NO3)2·6H2O溶液,經(jīng)700°C焙燒后,可在復(fù)合陰極表面形成針狀Co_3O_4。浸漬處理使700°C下LSCF-SDC復(fù)合陰極的界面阻抗由0.49Ω·cm~2降低至0.19Ω·cm~2,陰極的氧還原反應(yīng)活化能由1.52 eV降低至1.03 eV。此外,Co_3O_4浸漬陰極使700°C下單電池的功率密度由185 mW·cm-2提高至259 mW·cm-2。初步結(jié)果表明,通過(guò)Co_3O_4浸漬改性,可有效提高LSCF-SDC復(fù)合陰極和由其構(gòu)成的單電池的性能。本論文第三章通過(guò)離子浸漬法對(duì)Mn_(1.5)Co_(1.5)O_4(MCO)陰極骨架浸漬SDC納米顆粒,制備新型MCO-SDC復(fù)合陰極材料。對(duì)復(fù)合陰極的化學(xué)穩(wěn)定性、顯微組織、電化學(xué)性能及其單電池的功率密度等進(jìn)行分析,并與由機(jī)械混合法制備的MCO-SDC復(fù)合陰極進(jìn)行比較。實(shí)驗(yàn)結(jié)果表明,MCO與SDC的復(fù)合樣品在1200°C燒結(jié)2 h后沒(méi)有發(fā)生化學(xué)反應(yīng),說(shuō)明MCO與SDC在SOFC的工作溫度范圍內(nèi)具有良好的化學(xué)穩(wěn)定性。對(duì)多孔MCO陰極骨架浸漬含Sm和Ce的硝酸鹽溶液,在700°C焙燒2 h,后,可在陰極表面形成一層SDC納米顆粒。與機(jī)械混合法制備的MCO-SDC復(fù)合陰極相比,采用SDC浸漬處理所制備的MCO-SDC復(fù)合陰極在700°C下的界面阻抗從5.23Ω·cm-2降低至1.63Ω·cm-2。說(shuō)明以納米顆粒形式附著在MCO陰極表面的SDC,使陰極的三相反應(yīng)區(qū)由陰極/電解質(zhì)的界面延伸至陰極內(nèi)部,促進(jìn)了陰極表面的氧還原反應(yīng)過(guò)程。此外,浸漬SDC處理使SOFC單電池在700°C下的功率密度由252 mW·cm-2提高至366 mW·cm-2。本論文第四章通過(guò)檸檬酸法制備出了Sr2Fe1.5-xCuxMo0.5O6-δ(x=0,0.05,0.1,0.2,0.3)(SFCxM)粉體,并通過(guò)壓制燒結(jié)獲得燒結(jié)體,系統(tǒng)考察了Cu元素?fù)诫s量對(duì)SFM材料的物相,電導(dǎo)率,熱膨脹系數(shù)及電化學(xué)性能等的影響。XRD表明,隨著Cu元素?fù)诫s量的增加,所有SFCxM粉體均展現(xiàn)出立方型鈣鈦礦結(jié)構(gòu),沒(méi)有雜相出現(xiàn),并且材料的晶胞逐漸膨脹。熱膨脹性能測(cè)試表明,隨著Cu元素?fù)诫s量的增加,SFCxM材料的熱膨脹系數(shù)逐漸增加,為14.5~(-1)6.1 K~(-1)。電導(dǎo)率測(cè)試結(jié)果表明,隨著Cu元素?fù)诫s量的增加,SFCxM材料的電導(dǎo)率先增加后減小,當(dāng)摻雜量x=0.1時(shí),SFC0.1M材料在450°C下的電導(dǎo)率可以達(dá)到49.3 S·cm~(-1),是未摻雜Cu的SFM材料電導(dǎo)率的2.5倍。此外,SFC0.1M陰極材料在800°C下具有最低的界面阻抗,達(dá)0.26Ω·cm~2,僅為SFM材料界面阻抗的40%。當(dāng)SFC0.1M與SDC的質(zhì)量百分比為60:40時(shí),復(fù)合陰極的界面阻抗進(jìn)一步降低至0.15Ω·cm~2。
[Abstract]:Solid oxide fuel cell (Solid Oxide Fuel Cell, SOFC) because of its high energy conversion efficiency, wide range of optional fuel, environmental friendliness and widespread concern. Realize the development of the SOFC industry, the key is to reduce the working temperature and cost. However, with the decrease of temperature, cathodic polarization resistance increases, causing the battery the performance is reduced. Therefore, the development of high performance cathode material is one of the research hotspots in the field of SOFC. Adding appropriate electrolyte materials or catalytic materials for preparing composite cathode on the cathode material, can effectively improve the cathode surface redox reaction (ORR) process, so as to reduce the polarization resistance of the cathode ion impregnation method is. Novel porous SOFC composite electrode preparation technology. The technology is usually the first cathode made of porous skeleton, and then with the electrode active material in liquid phase infiltration driven by capillary force The porous skeleton, the precursor by low temperature decomposition of the corresponding oxide, so as to realize the composite electrode active material and cathode skeleton. The catalytic activity of electrode prepared by this process is high, low temperature performance is good, is to improve the performance of SOFC, an important way to reduce the working temperature of the size. The second chapter of this thesis by hydrothermal in porous La_ (0.6) Sr_ (0.4) Co_ (0.2) Fe_ (0.8) O_ (3- 8) -Sm_ (0.2) Ce_ (0.8) O_ (1.9) (LSCF-SDC) composite cathode surface load Co_3O_4 catalyst, the microstructure of samples before and after the change of phase structure, power density, electrochemical performance and single cell test. The experimental results show that the LSCF-SDC impregnated Co (NO3) cathode 2 6H2O solution, after calcined at 700 ~ C, can be formed on the surface of the acicular Co_3O_4. composite cathode impregnated the interface resistance of LSCF-SDC composite cathodes 700 DEG C by 0.49. Anti cm~2 decreased to 0.19. Cm~2., cathode The oxygen reduction reaction activation energy decreased from 1.52 eV to 1.03 eV. in addition, Co_3O_4 to 700 DEG C impregnated cathode power density of single cell by 185 mW - cm-2 increased to 259 mW cm-2. preliminary results show that Co_3O_4 modified by impregnation, can effectively improve the performance of LSCF-SDC composite cathode and single cell formed by this. The third chapter by ion impregnation method on Mn_ (1.5) Co_ (1.5) O_4 (MCO) cathode skeleton impregnated with SDC nanoparticles, preparation of novel MCO-SDC composite cathode materials. The chemical stability of composite cathode microstructure analysis and electrochemical performance of single cell power density, and compared with MCO-SDC composite cathode is prepared by mechanical mixing method. The experimental results show that the composite samples of MCO and SDC at 1200 DEG C sintering after 2 h without chemical reaction, MCO and SDC in the temperature range of SOFC has good chemical stability. Nitrate solution of porous MCO cathode skeleton impregnated containing Sm and Ce, at 700 C after 2 h roasting, one layer of SDC nanoparticles formed on the cathode surface. Compared with MCO-SDC composite cathode prepared by mechanical mixing method, the interface impedance by SDC impregnation for MCO-SDC composite cathode prepared at 700 ~ C from 5.23. Cm-2 decreased to 1.63. Cm-2. shows in the form of nanoparticles attached on the surface of SDC MCO cathode, the three-phase reaction zone of the cathode by extending to the interface inside the cathode cathode / electrolyte, promote the reaction process of the cathode surface oxygen reduction. In addition, dipping at SDC SOFC battery power density under the temperature of 700 C by 252 mW - cm-2 - cm-2. mW is increased to 366. The fourth chapter of this thesis by citric acid was prepared by Sr2Fe1.5-xCuxMo0.5O6- 8 (x=0,0.05,0.1,0.2,0.3) (SFCxM) powder, and sintered by pressing and sintering system, the effects of Cu element doping The amount of SFM mixed material phase, conductivity,.XRD coefficient and the electrochemical performance of thermal expansion shows that with the increase of Cu doping amount, all SFCxM powders exhibit a cubic perovskite structure without impurity phase appeared, and gradually expanded. The cell material thermal expansion performance tests show that with the increase of Cu doping amount, the thermal expansion coefficient of SFCxM gradually increased, 14.5~ (-1) 6.1 K~ (-1). The conductivity test results show that with the increase of Cu doping amount, the conductivity of SFCxM material increased first and then decreased, when the doping amount of x= 0.1, the electrical conductivity of SFC0.1M material under the temperature of 450 C can be up to 49.3 S - cm~ (-1), SFM is not the conductivity of doped Cu 2.5 times. In addition, SFC0.1M cathode material has the lowest interfacial impedance under the temperature of 800 C was 0.26. Cm~2, only the interface impedance of SFM material 40%. when the mass percentage of SDC was 60 and SFC0.1M At 40, the interface impedance of the composite cathode is further reduced to 0.15 Omega cm~2..

【學(xué)位授予單位】：合肥工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TM911.4

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本文編號(hào)：1636883