Abstract:
본 발명은 용융탄산염 연료전지(Molten Carbonate Fuel Cell; MCFC)용 연료극 및 그를 포함한 MCFC에 관한 것으로서, 본 발명에 의한 MCFC용 연료극은 기공면이 다공성 세라믹 막으로 코팅된 것을 특징으로 한다. 본 발명에 의한 MCFC용 연료극 및 이를 포함한 MCFC를 이용하면, MCFC의 전해질인 용융탄산염에 대한 연료극의 젖음성을 향상시키고 전해질 담지량을 증가시킴으로써, 과량의 전해질이 공급되어도 공기극 측의 플러딩이 발생하지 않도록 방지하며, MCFC의 장기 운전시 발생할 수 있는 용융탄산염의 증발 및 부식 등에 의한 전해질 소모와 그에 따른 전지 성능 저하를 억제할 수 있다. 또한, 본 발명은 연료극의 기공의 크기를 변화시키지 않음으로써 미세구조를 유지하여 연료극의 기체 확산 저항을 유발시키지 않는 효과가 있다. 따라서, 궁극적으로는 MCFC의 장기간 운전시 발생하는 전해질의 소모를 방지함으로써 안정한 성능을 유지한 채 MCFC를 장기간 운전시킬 수 있는 효과가 있다. 또한, 본 발명은 본 실시예에서 사용한 Ni, Ni-Cr 및 Ni-Al 합금 전극 뿐만 아니라, 최근 MCFC 연료극 재료로 부상하고 있는 Ni-기초 합금이나 금속간 화합물 전극의 경우에도 그대로 적용될 수 있으므로 연료극의 재료에 상관없이 연료극의 장기적 성능의 향상에 기여할 수 있다.
Abstract:
PURPOSE: Provided is an anode which has the inner surface of pore coated with porous ceramic film, shows improved wettability to electrolyte, and prevents the consumption of electrolyte, and thus can stably retain an excellent capability of battery when the battery works for a long time. CONSTITUTION: The anode for molten carbonate fuel cell comprising an anode, an electrolyte and a cathode, is characterized in that the anode has pore side coated with porous ceramic film. The anode consists of any one selected from the group consisting of pure Ni, Ni-containing metal mixture, Ni-containing alloy, and Ni-containing metal compound. The porous ceramic film is formed from any sol selected from the group Al oxide, Ce oxide, Zr oxide, Al hydroxide, Ce-hydroxide, and Zr hydroxide. The porous ceramic film is formed by sol gel process comprising the steps of impregnating the anode with ceramic sol and drying the anode.
Abstract:
PURPOSE: Provided are a process for producing a Li/Na electrolyte green sheet for a molten carbonate fuel cell(MCFC) and a method for pretreating and operating the MCFC containing the Li/Na electrolyte. CONSTITUTION: The Li/Na electrolyte green sheet is produced by the process comprising the steps of: ball-milling 100pts.wt. of a carbonate mixture powder comprising Li2CO3 and Na2CO3, 10-20pts.wt. of a binder, 10-20pts.wt. of a plasticizer, 1-2pts.wt. of a dispersing agent, 1-2pts.wt. of an antifoaming agent, and 50-100pts.wt. of ethanol solvent to prepare powdery slurry; tape-casting the powdery slurry; drying at a temperature of 40-90 deg.C. The method for pretreating and operating the MCFC containing the Li/Na electrolyte includes the steps of: supplying air at an ordinary temperature-300 deg.C, a mixture gas containing carbon dioxide and 5M of hydrogen at 300-650 deg.C, and a mixture gas comprising the hydrogen, the carbon dioxide, and steam after the temperature reaches 650 deg.C to an anode of the MCFC; supplying the air at an ordinary temperature-450 deg.C, inert gas or a mixture gas containing the inert gas and less than 10M of the hydrogen at 450-650 deg.C, and a mixture gas comprising the air and the carbon dioxide after the temperature reaches 650 deg.C to a cathode of the MCFC.
Abstract:
PURPOSE: A ceramic fiber-reinforced matrix for a molten carbonate fuel cell and a method for manufacturing the same are provided which restrains cracks of matrix due to the thermal cycling that can be generated during the long term running of the molten carbonate fuel cell and the resulting deterioration of the cell. CONSTITUTION: The method for manufacturing the fiber-reinforced matrix for a molten carbonate fuel cell comprises the steps of preparing a slurry by ball milling the mixture after mixing LiAlO2 powder, dispersant, antifoaming agent and solvent; adding binder, plasticizer and ceramic fiber to the prepared slurry, mixing the materials, and ball milling the mixture; degassing the ball milled slurry; and drying after molding the degassed slurry in a tape casting process, wherein the LiAlO2 powder is selected from the group consisting of γ-LiAlO2, β-LiAlO2 and α-Al2O3, the LiAlO2 powder is a mixture of LiAlO2 HSA (high surface area) having a size of 5 microns or less and LiAlO2 LSA (low surface area) having a size of 10 microns or less, and the LSA is 10 to 30 weight parts based on the 100 weight parts of fiber and powder, wherein the ceramic fiber is selected from the group consisting of α-Al2O3, γ-LiAlO2, β-LiAlO2, α-LiAlO2, LiZrO3, Y2O3 stabilized ZrO3, LiTaO3, LiNbO3 and CeO2, and used in an amount of 5 to 20 weight parts based on 100 weight parts of powder and fiber, and wherein 10 to 40 weight parts of binder, 10 to 40 weight parts of plasticizer, 1 to 5 weight parts of antifoaming agent, 1 to 2 weight parts of dispersant and 150 to 250 weight parts of solvent are used based on 100 weight parts of powder and fiber.