| 摘要: | 可逆固態氧化物電池(Reversible Solid Oxide Fuel Cells, R-SOFCs)為一種兼具發電與儲能功能的可逆燃料電池。SOEC在高溫下電解水氣並以氫能進行電力儲存，待需要電力時再將氫能進行SOFC轉換成電力使用。該方法可以避免再生能源之間歇性發電，導致電力可能發生輸出斷層，即可有效提升可再生能源的產量。另外，此裝置可視為一個既穩定又乾淨的系統，並同時降低溫室氣體排放量，因為副產物僅有水氣，可當作新世代的潔淨能源。
在本實驗研究中，將探討LSCF以及GCCCO作為固態氧化物燃料電池之空氣電極材料，以及通過使用旋轉塗佈以及脈衝雷射技術製備空氣電極功能層的方法，探討其單電池於R-SOFC下的性能。LSCF作為空氣電極具有良好的電子與氧離子傳導能力，且在中溫操作下具有足夠高的雙向輸出性能；而GCCCO具有良好的電子、氧離子及質子之傳輸能力，可以在中溫下進一步提升R-SOFC性能。另外，將透過改變空氣電極功能層的製備方法，進一步降低歐姆和極化阻抗，使得單電池之能量密度以及電流轉換效率進一步地提升。因此本實驗研究將建立一套可靠的燃料電池(FC)與電解電池(EC)的測量方法以及數據分析，並在不同測量溫度下探討其電化學性能。
本實驗研究顯示，透過PLD製備空氣電極功能層的GCCCO單電池，其FC模式在800 ℃下的最高功率密度為962.4 mW/cm2，與旋轉塗佈製備的LSCF單電池相比高了128 %，其原因為歐姆阻抗以及極化阻抗分別降低了54 %和85 %。而PLD製備空氣電極功能層的GCCCO單電池在EC模式下，其產氫量為3.31E-06 g/s以及其法拉第效率為41.5 %，相對旋轉塗佈製備的LSCF單電池而言僅有25.7 %。
;Operation of Reversible Solid Oxide Fuel Cells (R-SOFCs) have both power generation mode (SOFC) and energy storage mode (SOEC). SOEC electrolyzes water vapor at high temperature and stores electricity as hydrogen energy. When the times as electricity is needed, hydrogen is then converted into electricity by SOFC mode. In this way, the characteristics of intermittent power when generating electricity by renewable energy can be avoided, which may cause electricity output faults if more electricity was required at busy times. In addition, this device can be regarded as a stable and clean system as water vapor is the only by-product, which may also reduce greenhouse gas emissions.
In this study, the performance of LSCF and GCCCO as air electrode in R-SOFC, alongside with different methods of preparing interlayer, spin coating and PLD, were explored. As an air electrode, both LSCF and GCCCO has good electron and oxygen ion conductivities, and also shows good performance in R-SOFC at medium temperature. However, GCCCO can also conduct protons, which may further increase the performance of R-SOFC. Furthermore, the ohmic and polarization resistance will be further reduced by changing the preparation method of the interlayer. Hence, the maximum power density and Faradic efficiency of a single cell can be further improved. Moreover, a reliable measurement method will be established in both FC and EC mode in this study, as well as its electrochemical data analysis on different temperatures will be discussed.
This experimental study shows that the maximum power density of the GCCCO single cell prepared by PLD interlayer at 800°C in FC mode is 962.4 mW/cm2, which is 128 % higher than the LSCF single cell prepared by spin coating interlayer. Because the ohmic and polarization impedance are reduced by about 54 % and 85 % respectively. In EC mode, the GCCCO single cell prepared by PLD interlayer has a hydrogen production rate of 3.31E-06 g/s and its Faradaic efficiency of 41.5 %. In comparison, the Faradaic efficiency of LSCF single cell prepared by spin coating has only 25.7%. |
