題目：SOFC for Clean Power Generation?
報告人：劉興博教授, West Virginia University,USA
時 ?間：2015年10月26日（星期一）10:00-11:00
地 ?點：商船學院G樓114室

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報告人簡歷
劉興博教授1999年于北京科技大學獲得材料科學與工程博士學位，現為西弗吉尼亞大學機械與航天工程系教授、科研副系主任，任美國高溫合金委員會主席，并任職于美國能量轉換及存儲委員會和美國陶瓷協會科學部門。長期從事于清潔能源轉換與存儲用先進功能材料、燃料電池、高溫合金、腐蝕與防護等方向的研究，取得了大量研究成果。目前，已發100多篇高水平SCI論文，還獲得了眾多的學術榮譽，參與舉辦過20多次國際學術會議等。其研究成果曾榮獲美國“R&D 100 Award”等多項大獎。
Dr. Xingbo Liu graduated from University of Science and Technology Beijing in 1999, and he subsequently went to West Virginia University as a postdoc. Currently, he is the Professor and Associate Chair for Research in Mechanical & Aerospace Engineering Department at WVU. Dr, Liu’s main research interests are advanced high temperature materials for next generation energy conversion and storage and his research focuses are Ni-base superalloys and solid oxide fuel cells. Dr. Liu has received numerous awards including R&D 100 Award (2011), TMS Early Career Faculty Fellow Award (2010), WVU CEMR Researcher of the Year (2015, 2011), Outstanding Researcher Awards (2015, 2011, 2009, 2008), and others. In 2015, he was elected as the Fellow of ASM International.
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報告摘要
Solid Oxide Fuel Cells (SOFCs) is one of the promising alternative technologies for inefficient coal combustion for power generation, which can potentially operate on syngas obtained from coal. The main advantages of SOFCs are high overall plant efficiency (when the waste heat is used for bottoming cycles) and suitability for carbon sequestration. However there are still some unresolved problems with performance durability of these devices when operating on coal syngas, which inherently has some undesirable contaminants such as sulfur and phosphorus compounds.
At anode side, the most important issues are (1) understanding the effects of impurities on the performance and microstructural degradation of Ni-YSZ anodes, and (2) developing impurity-tolerant anodes. I will present our investigation on effect of phosphorous and sulfur on both Ni-YSZ and perovskite anodes and our attempts to develop S-tolerant anode. The sulfur tolerance introduced by LaxCe1-xO2 coating has been tested with MSRI cells by using Pt paste and nickel mesh on the anode as current collector. The degradation for the impregnated MSRI cell was postponed and the degradation degree after H2S attack was also alleviated.
At cathode side, our approaches are to develop electrochemical models to simulate the kinetics of oxygen reduction and reaction (ORR) and to improve the cathode performance by employing infiltration method. Our ORR modeling recognize the overall charge-transfer reactions canproceed along both surface pathway via triple-phase boundary (3PB) and a bulk pathway via electrolyte/cathode interface (2PB) of SOFC cathodes. We analyzed the electrochemical behavior of LSM-type MIEC cathode by incorporating multi-step charge-transfer into the bi-pathway kinetics model. The results are compared to the experimental data to examine the physical validity of the assumed oxygen reduction scenario, and the consequent implication on performance improvement methods for SOFC cathode is also discussed. Experimentally, we infiltrated SDC into LSM cathode and showed the significant performance improvement and polarization resistance decrease at 800C.
On the system level, Cr-poisoning from interconnect is still one the major reasons to cause system performance degradation. Mn-Co spinel has been identified as the most promising candidate for SOFC interconnect coating due to its high electrical conductivity, capability to block chromium evaporation, and match with CTE with other cell components, etc. We developed low-cost coating methods by electroplating and electrophoretic deposition (EPD). Electroplating of alloys, followed by controlled oxidation to the desired spinel phase, offers advantages in terms of low cost and applicable to complex shapes, as compared to other coating methods. However, the huge difference on standard deposition potentials between Co2+/Co (-0.28VSCE) and that of Mn2+/Mn(-1.18VSCE)makes it very difficult to co-deposit Mn-Co alloys. We have been successfully co-deposited the alloys by optimizing bath chemistry, deposition voltage and current, as well as the deposition cycles during the pulse plating process.