本文選題：中溫固體氧化物燃料電池 + 鈣鈦礦��； 參考：《吉林大學(xué)》2014年博士論文

【摘要】：固體氧化物燃料電池(SOFC)作為一種清潔高效的能源轉(zhuǎn)換裝置，受到人們的廣泛關(guān)注和研究。傳統(tǒng)的SOFC研究中，通常使用La1xSrxMnO3(LSM)氧化物作為SOFC的陰極材料。LSM陰極材料與傳統(tǒng)的電解質(zhì)材料YSZ熱兼容，只有在800-1000C的高溫環(huán)境下才能表現(xiàn)出穩(wěn)定優(yōu)良的電學(xué)和電化學(xué)性能。當(dāng)SOFC的工作溫度下降到600-800C的中溫范圍以后，該類傳統(tǒng)陰極材料的氧離子傳導(dǎo)性能和催化活性會(huì)極大地降低，成為限制中溫固體氧化物燃料電池(IT-SOFC)性能的主要原因。 在IT-SOFC陰極材料中，單摻雜和雙摻雜的鈷基系列鈣鈦礦陰極材料具有較高的電化學(xué)性能，但這類含鈷的材料均存在穩(wěn)定性差，熱膨脹系數(shù)過高，高制作成本的問題。最近，雙鈣鈦礦陰極材料由于具有較高的電導(dǎo)率和氧空位濃度而在中溫范圍內(nèi)表現(xiàn)出比傳統(tǒng)陰極材料更優(yōu)良的電化學(xué)性能，其作為有發(fā)展前途的IT-SOFC陰極材料備受關(guān)注，然而，含鈷的雙鈣鈦礦陰極材料仍存在與電解質(zhì)的熱膨脹匹配問題。陰極材料本身的性質(zhì)對(duì)開發(fā)高性能IT-SOFC起著極為關(guān)鍵的作用，因此開發(fā)中溫條件下具有優(yōu)良電化學(xué)性能的陰極材料尤為重要。 本文采用傳統(tǒng)的固相反應(yīng)法分別制備了無鈷的鈣鈦礦結(jié)構(gòu)陰極材料Ba0.5Sr0.5Fe0.9Nb0.1O3-，雙鈣鈦礦結(jié)構(gòu)陰極材料YBaCo2-xCuxO5+(x=0.2,0.4,0.6)，無鈷雙鈣鈦礦結(jié)構(gòu)陰極材料Ln2MnFeO6-(Ln=La, Pr, Nd, Sm)和AA’MnFeO6-(A=Ca, Sr, Ba; A’=La, Pr)，并對(duì)其性能進(jìn)行了研究。 在無鈷鈣鈦礦結(jié)構(gòu)陰極材料Ba0.5Sr0.5Fe0.9Nb0.1O3-(BSFN)的實(shí)驗(yàn)研究中，我們對(duì)材料的燒結(jié)溫度，電導(dǎo)率，熱膨脹和電化學(xué)性能進(jìn)行了研究，并對(duì)比了采用SDC和LSGM電解質(zhì)的電化學(xué)性能。XRD表明，BSFN在空氣中1250oC燒結(jié)10h可得到單相立方鈣鈦礦結(jié)構(gòu)的材料。電導(dǎo)率在425C附近發(fā)生傳導(dǎo)機(jī)制的轉(zhuǎn)變，由半導(dǎo)體導(dǎo)電轉(zhuǎn)變?yōu)榻饘賹?dǎo)電。在電化學(xué)性能的比較中，當(dāng)采用LSGM電解質(zhì)時(shí)，BSFN陰極材料表現(xiàn)出的極化阻抗值和電池功率密度均比使用SDC電解質(zhì)時(shí)要高，700oC時(shí)在SDC和LSGM兩種電解質(zhì)上測(cè)得的極化阻抗值分別為0.078和0.062cm2，800oC時(shí)單電池BSFN/SDC/Ni-SDC和BSFN/LSGM/SDC/Ni-SDC的最大電池功率密度分別為414和516mW cm2。良好的電化學(xué)性能說明該材料可作為IT-SOFC陰極的候選材料。 陰極材料YBaCo2-xCuxO5+(x=0.2,0.4,0.6)(YBCC)具有雙鈣鈦礦結(jié)構(gòu)，在實(shí)驗(yàn)中表現(xiàn)出優(yōu)良的電化學(xué)性能。我們探究了銅摻雜對(duì)該陰極材料性能的影響。結(jié)果表明，在950°C燒結(jié)20h可獲得單相的YBCC，且在低于900°C的溫度下與La0.9Sr0.1Ga0.8Mg0.115Co0.085O2.85(LSGMC)電解質(zhì)具有良好的化學(xué)兼容性。隨著銅的摻雜量的增加，YBCC的電導(dǎo)率降低，，且在摻雜量達(dá)到0.6時(shí)樣品的電導(dǎo)率規(guī)律完全轉(zhuǎn)變?yōu)榘雽?dǎo)體導(dǎo)電。在熱膨脹測(cè)試中，陰極材料YBCC表現(xiàn)出較低的平均熱膨脹系數(shù)，在30-900°C溫度范圍內(nèi)的約為15×106K1。在電化學(xué)性能測(cè)試中，銅摻雜為0.2時(shí)的樣品表現(xiàn)出最好的電化學(xué)性能，700°C時(shí)極化阻抗值為0.012cm2，800°C時(shí)電池最大功率密度達(dá)到811mW cm2。 為了開發(fā)新型無鈷雙鈣鈦礦IT-SOFC陰極材料，我們制備和研究了無鈷雙鈣鈦礦陰極材料Ln2MnFeO6-(LnMFO)(Ln=La, Pr, Nd, Sm)和AA’MnFeO6-(AA’MF)(A=Ca, Sr, Ba; A’=La, Pr)。在Ln2MnFeO6-(Ln=La, Pr, Nd, Sm)陰極材料的研究中，該材料總體表現(xiàn)出良好的熱學(xué)性質(zhì)，在30-1000C的溫度范圍內(nèi)平均熱膨脹系數(shù)為~10×106K1，與常用電解質(zhì)具有良好的熱匹配性，但該材料的電導(dǎo)率與阻抗值相對(duì)較低。為了進(jìn)一步優(yōu)化Ln2MnFeO6-(Ln=La, Pr, Nd, Sm)材料的電化學(xué)性能，我們選取綜合性能較好的La2MnFeO6-和Pr2MnFeO6-樣品進(jìn)一步研究，通過在A位摻雜堿土金屬元素來優(yōu)化這兩種陰極材料的性能，得到AA’MnFeO6-(A=Ca, Sr, Ba; A’=La, Pr)陰極材料。 在AA’MnFeO6-(A=Ca, Sr, Ba; A’=La，Pr)陰極材料的研究中，Ba摻雜樣品由于有雜質(zhì)相產(chǎn)生，因此最終研究樣品為A位摻雜Ca和Sr的AA’MnFeO6-(A=Ca, Sr, Ba; A’=La, Pr)陰極材料。通過一系列電學(xué)，熱學(xué)，電化學(xué)相關(guān)測(cè)試，我們發(fā)現(xiàn)，與摻雜Ca的材料相比，摻雜Sr的樣品SrLaMnFeO6-和SrPrMnFeO6-的電導(dǎo)率增加，極化阻抗值減小，700oC時(shí)極化阻抗分別為4.29和4.97cm2，850oC時(shí)單電池的功率密度分別為432和392mW cm2。
[Abstract]:As a clean and efficient energy conversion device, the solid oxide fuel cell (SOFC) is widely concerned and studied. In the traditional SOFC study, the La1xSrxMnO3 (LSM) oxide is usually used as the cathode material of the SOFC and the.LSM cathode material is compatible with the traditional electrolyte material YSZ, only in the high temperature environment of 800-1000C. When the working temperature of SOFC drops to the medium temperature range of 600-800C, the oxygen ion conductivity and catalytic activity of this kind of traditional cathode material will be greatly reduced and the main reason for limiting the performance of the medium temperature solid oxide fuel cell (IT-SOFC).
In IT-SOFC cathode materials, single and double doped cobalt based perovskite cathode materials have high electrochemical properties, but these cobalt containing materials have the problems of poor stability, high thermal expansion coefficient and high production cost. Recently, the Double Perovskite Cathode material has high conductivity and oxygen vacancy concentration at middle temperature. The electrochemical performance of IT-SOFC cathode material is better than that of the traditional cathode material. It has attracted much attention as a promising cathode material. However, the dual Perovskite Cathode material with cobalt still exists the problem of matching the thermal expansion of the electrolyte. The properties of the cathode material itself play a crucial role in the development of high performance IT-SOFC. It is particularly important to develop cathode materials with excellent electrochemical performance under moderate temperature.
In this paper, the cobalt free perovskite structure cathode material Ba0.5Sr0.5Fe0.9Nb0.1O3-, the double perovskite structure cathode material YBaCo2-xCuxO5+ (x=0.2,0.4,0.6), the cobalt free perovskite structure cathode material Ln2MnFeO6- (Ln=La, Pr, Nd, Sm) and AA 'MnFeO6- are prepared by the traditional solid state reaction method respectively. The study was done.
In the experimental study of the cobalt free perovskite structure cathode material Ba0.5Sr0.5Fe0.9Nb0.1O3- (BSFN), the sintering temperature, electrical conductivity, thermal expansion and electrochemical properties of the materials were studied. The electrochemical properties of SDC and LSGM electrolytes were compared. The results showed that the single-phase cubic perovskite junction could be obtained by 1250oC sintered 10h in the air of BSFN. The conductivity of the conduction mechanism is changed from semiconductor conduction to metal conduction in the vicinity of 425C. In the comparison of electrochemical properties, when LSGM electrolytes are used, the polarization impedance values and the power density of the BSFN cathode materials are higher than those of the SDC electrolyte, and 700oC is on the SDC and LSGM two electrolytes at the time of 700oC. When the measured polarization impedance values are 0.078 and 0.062cm2800oC, the maximum battery power density of the single cell BSFN/SDC/Ni-SDC and BSFN/LSGM/SDC/Ni-SDC is 414 and 516mW cm2., respectively, indicating that the material can be used as a candidate for the IT-SOFC cathode.
The cathode material YBaCo2-xCuxO5+ (x=0.2,0.4,0.6) (YBCC) has a double perovskite structure and shows excellent electrochemical performance in the experiment. We explore the effect of copper doping on the performance of the cathode material. The results show that the single phase YBCC can be obtained at 950 degree C sintering 20h and La0.9Sr0.1Ga0.8Mg0.115Co0.085O2.85 (L) at a temperature lower than 900 degree C. SGMC) the electrolyte has good chemical compatibility. With the increase of copper doping, the conductivity of YBCC decreases, and the conductivity law of the sample is completely converted to semiconductor conduction when the amount of doping reaches 0.6. In the thermal expansion test, the cathode material YBCC shows a lower average thermal expansion coefficient, which is about 15 in the range of 30-900 C temperature. In the electrochemical performance test of 106K1., the sample with copper doped to 0.2 shows the best electrochemical performance. The maximum power density of the battery is 811mW cm2. when the polarization impedance is 0.012cm2800 degree C at 700 C.
In order to develop new cobalt free perovskite IT-SOFC cathode materials, we have prepared and studied cobalt free Perovskite Cathode material Ln2MnFeO6- (LnMFO) (Ln=La, Pr, Nd, Sm) and AA 'MnFeO6- (AA' MF). In the temperature range of 30-1000C, the average thermal expansion coefficient is ~10 x 106K1, which has good thermal matching with the commonly used electrolyte, but the conductivity and impedance of the material are relatively low. In order to further optimize the electrochemical properties of Ln2MnFeO6- (Ln=La, Pr, Nd, Sm) materials, we choose a better comprehensive performance of La2MnFeO6- and Pr2MnFeO6- samples. In the further study, the properties of the two cathode materials were optimized by doping the alkaline earth metal elements in the A bit, and the cathode materials of AA 'MnFeO6- (A=Ca, Sr, Ba; A' =La, Pr) were obtained.
In the study of AA 'MnFeO6- (A=Ca, Sr, Ba; A' =La, Pr) cathode materials, Ba doped samples are produced because of the impurity phase, so the final research sample is the cathode material for A bit doping Ca and Sr. The conductivity of the samples SrLaMnFeO6- and SrPrMnFeO6- of the mixed Sr increases, the polarization impedance decreases. The power density of the single cell is 432 and 392mW cm2., respectively, when the polarization impedance is 4.29 and 4.97cm2850oC at 700oC, respectively.
【學(xué)位授予單位】：吉林大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2014
【分類號(hào)】：TM911.4

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 劉建國(guó),孫公權(quán);燃料電池概述[J];物理;2004年02期

本文編號(hào)：2057400