銀基陶瓷復(fù)合電極的電性能及其在固體氧化物燃料電池中的應(yīng)用研究
發(fā)布時(shí)間：2018-12-08 16:30
【摘要】：固體氧化物燃料電池(SOFCs)是一種能夠直接將燃料中的化學(xué)能轉(zhuǎn)化為電能的發(fā)電裝置,具有電轉(zhuǎn)換效率高、對(duì)環(huán)境友好、燃料適應(yīng)性廣及壽命長(zhǎng)等優(yōu)點(diǎn),被公認(rèn)為是具有良好發(fā)展前景的新型發(fā)電技術(shù)。SOFC的電極材料對(duì)SOFC的性能具有重要的影響。傳統(tǒng)的SOFC采用鎳基陽(yáng)極和摻雜錳酸鑭復(fù)合陰極,但鎳基陽(yáng)極在使用含碳燃料時(shí)會(huì)因?yàn)榇龠M(jìn)積炭而降低電池性能,錳酸鑭陰極的氧還原能力也不夠強(qiáng),特別是在溫度降低時(shí),陰極極化電阻將顯著增大,從而嚴(yán)重影響電池的輸出性能。針對(duì)傳統(tǒng)電極存在的問(wèn)題,本論文研究了銀基陶瓷復(fù)合材料作為SOFC的陰極和陽(yáng)極的性能。首先采用傳統(tǒng)YSZ電解質(zhì),分別采用不同Ag比例的Ag-YSZ和Ag-GDC為電極材料,制備對(duì)稱電極,在空氣中對(duì)其進(jìn)行了交流阻抗譜測(cè)試,分別選出Ag-YSZ和Ag-GDC電極的最佳成分比;結(jié)合相應(yīng)電極材料組裝成的SOFC電化學(xué)性能測(cè)試結(jié)果,區(qū)分出陰極和陽(yáng)極的極化電阻,并對(duì)實(shí)驗(yàn)結(jié)果進(jìn)行了討論和分析。結(jié)果表明,在相同的Ag含量(質(zhì)量比)時(shí),Ag-YSZ在空氣下的極化阻抗普遍小于Ag-GDC,且當(dāng)Ag的含量為65%時(shí),Ag-YSZ(65Ag-YSZ)在空氣中的極化阻抗最低,而Ag-GDC在空氣中的最低極化阻抗時(shí)的Ag含量是70%(70Ag-GDC)。分別采用65Ag-YSZ(Ag的質(zhì)量百分?jǐn)?shù)為65%)和70Ag-GDC(Ag的質(zhì)量百分?jǐn)?shù)為70%)為電極制備SOFC單電池并使用加濕氫氣(3 vol.%H2O)為燃料進(jìn)行測(cè)試。800?C時(shí),采用65Ag-YSZ和70Ag-GDC既作為陰極又作為陽(yáng)極的電池,前者的開(kāi)路電壓和最大功率密度分別為1.08 V和200mW·cm-2,后者的分別為1.09 V和214 mW·cm-2。采用阻抗譜測(cè)試和分析結(jié)果表明,雖然在空氣氣氛中Ag-YSZ的極化電阻比Ag-GDC低,但在加濕氫氣中,Ag-GDC的極化電阻比Ag-YSZ低,說(shuō)明Ag-YSZ更適合用作陰極,而Ag-GDC更適合用作陽(yáng)極。在上述研究基礎(chǔ)上,研究了銀基陶瓷復(fù)合電極用于直接碳固體氧化物燃料電池(DC-SOFC)的性能。用65Ag-GDC作為DC-SOFC的陽(yáng)極,65Ag-YSZ作為其陰極,830?C測(cè)試溫度下,其最大輸出功率密度能達(dá)到~339 m W·cm-2,比傳統(tǒng)NiO-YSZ陽(yáng)極的性能要優(yōu)越許多。結(jié)果表明,采用Ag-GDC復(fù)合電極材料能夠有效地提高電池的輸出性能。
[Abstract]:Solid oxide fuel cell (SOFCs) is a kind of power generation device which can directly convert the chemical energy of fuel into electric energy. It has the advantages of high efficiency of electric conversion, friendly environment, wide fuel adaptability and long life. The electrode material of SOFC has an important influence on the performance of SOFC. The traditional SOFC uses nickel based anode and doped lanthanum manganate composite cathode, but the nickel base anode can reduce the battery performance because of promoting carbon deposition, and the oxygen reduction ability of lanthanum manganate cathode is not strong enough, especially when the temperature is lowered. The cathode polarization resistance will increase significantly, which will seriously affect the output performance of the battery. Aiming at the problems of traditional electrodes, the properties of silver based ceramic composites as cathodes and anodes of SOFC were studied in this paper. Firstly, symmetrical electrodes were prepared by using traditional YSZ electrolytes and Ag-YSZ and Ag-GDC with different Ag ratios, respectively, and were measured by AC impedance spectroscopy in air. The optimum composition ratio of Ag-YSZ and Ag-GDC electrode was selected. The polarization resistance of cathode and anode is distinguished by combining the electrochemical performance test results of SOFC assembled with corresponding electrode materials and the experimental results are discussed and analyzed. The results show that at the same Ag content (mass ratio), the polarization impedance of Ag-YSZ in air is generally lower than that of Ag-GDC, and when the content of Ag is 65, the polarization impedance of Ag-YSZ (65Ag-YSZ) in air is the lowest. The Ag content of Ag-GDC in air at the lowest polarization impedance is 70% (70Ag-GDC). Using 65Ag-YSZ (65% of Ag) and 70Ag-GDC (70% of Ag) as electrodes to prepare SOFC single cell and test with 3 vol.%H2O as fuel. Using 65Ag-YSZ and 70Ag-GDC as both cathode and anode, the open circuit voltage and maximum power density of the former are 1.08 V and 200mW cm-2, respectively, the latter are 1.09 V and 214 mW cm-2., respectively. The results of impedance spectroscopy show that the polarization resistance of Ag-YSZ is lower than that of Ag-GDC in air atmosphere, but the polarization resistance of Ag-GDC is lower than that of Ag-YSZ in humidified hydrogen, which indicates that Ag-YSZ is more suitable as cathode. Ag-GDC is more suitable as anode. Based on the above research, the performance of silver based ceramic composite electrode for direct carbon solid oxide fuel cell (DC-SOFC) was studied. Using 65Ag-GDC as the anode of DC-SOFC and 65Ag-YSZ as its cathode, the maximum output power density of 830 鈩，
本文編號(hào)：2368647
[Abstract]:Solid oxide fuel cell (SOFCs) is a kind of power generation device which can directly convert the chemical energy of fuel into electric energy. It has the advantages of high efficiency of electric conversion, friendly environment, wide fuel adaptability and long life. The electrode material of SOFC has an important influence on the performance of SOFC. The traditional SOFC uses nickel based anode and doped lanthanum manganate composite cathode, but the nickel base anode can reduce the battery performance because of promoting carbon deposition, and the oxygen reduction ability of lanthanum manganate cathode is not strong enough, especially when the temperature is lowered. The cathode polarization resistance will increase significantly, which will seriously affect the output performance of the battery. Aiming at the problems of traditional electrodes, the properties of silver based ceramic composites as cathodes and anodes of SOFC were studied in this paper. Firstly, symmetrical electrodes were prepared by using traditional YSZ electrolytes and Ag-YSZ and Ag-GDC with different Ag ratios, respectively, and were measured by AC impedance spectroscopy in air. The optimum composition ratio of Ag-YSZ and Ag-GDC electrode was selected. The polarization resistance of cathode and anode is distinguished by combining the electrochemical performance test results of SOFC assembled with corresponding electrode materials and the experimental results are discussed and analyzed. The results show that at the same Ag content (mass ratio), the polarization impedance of Ag-YSZ in air is generally lower than that of Ag-GDC, and when the content of Ag is 65, the polarization impedance of Ag-YSZ (65Ag-YSZ) in air is the lowest. The Ag content of Ag-GDC in air at the lowest polarization impedance is 70% (70Ag-GDC). Using 65Ag-YSZ (65% of Ag) and 70Ag-GDC (70% of Ag) as electrodes to prepare SOFC single cell and test with 3 vol.%H2O as fuel. Using 65Ag-YSZ and 70Ag-GDC as both cathode and anode, the open circuit voltage and maximum power density of the former are 1.08 V and 200mW cm-2, respectively, the latter are 1.09 V and 214 mW cm-2., respectively. The results of impedance spectroscopy show that the polarization resistance of Ag-YSZ is lower than that of Ag-GDC in air atmosphere, but the polarization resistance of Ag-GDC is lower than that of Ag-YSZ in humidified hydrogen, which indicates that Ag-YSZ is more suitable as cathode. Ag-GDC is more suitable as anode. Based on the above research, the performance of silver based ceramic composite electrode for direct carbon solid oxide fuel cell (DC-SOFC) was studied. Using 65Ag-GDC as the anode of DC-SOFC and 65Ag-YSZ as its cathode, the maximum output power density of 830 鈩，
本文編號(hào)：2368647
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