• Journal of Electrochemical Science and Technology
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• 제7권2호
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• pp.91-96
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• 2016

Oxidation behaviours of ash free coal (AFC), carbon, and H₂ fuels were investigated with a coin type molten carbonate fuel cell. Because AFC has no electrical conductivity, its oxidation occurs via gasification to H₂ and CO. An interesting behaviour of mass transfer resistance reduction at higher current density was observed. Since the anode reaction has the positive reaction order of H₂, CO₂ and H₂O, the lack of CO₂ and H₂O from AFC results in a significant mass transfer resistance. However, the anode products of CO₂ and H₂O at higher current densities raise their partial pressure and mitigate the resistance. The addition of CO₂ to AFC reduced the resistance sufficiently, thus the resistance reduction at higher current densities did not appear. Electrochemical impedance results also indicate that the addition of CO₂ reduces mass transfer resistance. Carbon and H₂ fuels without CO₂ and H₂O also show similar behaviour to AFC: mass transfer resistance is diminished by raising current density and adding CO₂.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 하계학술대회 논문집
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• pp.255-258
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• 1991

MCFC are expected as an electric and thermal power source of the urban cogenerating system because MCFC have higher electric power efficiency and better thermal power quality. However, the MCFC which use strorgly corrosive molten Carbonate at $650^{\circ}C$ have many problems. Material issues with the molten carbonate fuel cell in clude anode creep, conthode dissolution and bipolar plate corrosion. The objectives of this study are to examied fabrication process and characteristics of anode electrode.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.82.1-82.1
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• 2010

Recently, Molten carbonate fuel cells(MCFCs) have been developing to get a good durability and economic feasibility for commercialization. To achieve these objectives, the cost of nickel based electrodes should be reduced. Regular anode thickness used in MCFCs is normally 0.7mm. Thus, in our study, the purpose was to reduce anode thickness up to 0.3 mm keeping MCFC performance on standard levels. In-situ sintering has been used, with 2 different fabrication methods (method A and B) and 2 different supports (support 1 and 2). Voltage losses at different temperature (600,620,640,$650^{\circ}C$) and after 1000 hours showed the higher performance that can be obtained using method B and support 2. After single cell test, an open-circuit voltage(OCV) of 1.075 V and a closed-circuit voltage(CCV) of 0.829V were obtained, at current density of $150mV/cm^2$. Also the voltage loss ratio at different cell temperature was lower in the case of method B and support 2. According to these results, the cost of anode fabrication can be reduced in the future, contributing for the economical feasibility of MCFCs.

• 신재생에너지
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• 제4권1호
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• pp.11-18
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• 2008

In-situ lithiated NiO has been manufactured as a conventional cathode material of molten carbonate fuel cell (MCFC), however this material has a weakness for commercialization of MCFC because NiO is spontaneously dissolved into the electrolyte under MCFC operating conditions, resulting in short circuit between cathode and anode. In this research, therefore, $Co(OH)_2$-coated Ni powder was prepared by precipitation method with controlling pH at low temperature and atmospheric pressure. Modified cathode was fabricated by a conventional tape casting method and sintered at 700$^{\circ}C$ in a $H_2/N_2$ atmosphere, Based on characterization result, Pore size distribution and porosity was suitable for the cathode of MCFC. According to the result of dissolution, Ni solubility of modified cathode was 33% lower than that of conventional cathode. In addition, modified electrode showed a good performance from the single cell operation.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.927-933
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• 2000

The molten carbonate fuel cell has conspicuous feature and high potential in being used as an energy converter of various fuel to electricity and heat. However, the MCFC which use strongly corrosive molten carbonate at 650$^{\circ}C$ have many problem. Systematic investigation on corrosion behavior of Fe/20Cr/Ti alloys has been done in (62+38)mol% (Li+K)CO3 melt at 923K by using steady state polarization and electrochemical impedance spectroscopy method. And, The research and development for the solid oxide fuel cell have been promoted rapidly and extensively in recent years, because of their high efficiency and future potential. Therefore this paper describes the manufacturing method and characteristics of anode electrode for SOFC, by the way , Ni-YSZ materials are used as anode of SOFC widely. So in this experiments, we investigated the optimum content of Ni, by the impedance characteristics, overvoltage. As a results, the performance of Ni-YSZ anode(40vo1%) was better excellent than the others.

• 한국수소및신에너지학회논문집
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• 제20권6호
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• pp.479-484
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• 2009

The effect of anode gas channel height on gas diffusion and cell performance in a 100 $cm^2$ class molten carbonate single cell is investigated. Single cell separators with three different channel height are used. The effect of the gas channel height on the distribution of the reactive gas concentration is evaluated by the two-dimensional concentration diffusion equation. The overpotential caused by concentration drop with different channel height is estimated by the voltage decay related to diffusion of reactants, well known as concentration polarization, using limiting current density. The estimation could have the possibility to identify the reactant mass transfer polarization in the complicate factors of the overall electrodes.

• 조명전기설비학회논문지
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• 제28권3호
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• pp.26-31
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• 2014

High temperature fuel cell system, such as molten carbonate fuel cells(MCFC) and solid oxide fuel cells(SOFC), are capable of operating at MW rated power output. The power output change of high temperature fuel cell imposes the thermal and mechanical stresses on the fuel cell stack. To minimize the thermal-mechanical stresses on the stack and increase the systems reliability, we should divide the power plant configuration to several banks. However, the improvement of reliability in fuel cell power plant system causes an increase of the investment cost, for example, replacement costs, labor costs, and so on. For this reason - the balance between investment and reliability improvement - many studies about the appropriate level of investment have been conducted. In this paper, we evaluate the cost for operation and installation, the benefit for electric energy and thermal energy sales, and the system reliability for several cases : these cases relate with the bank configuration.

• 한국가스학회지
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• 제18권2호
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• pp.28-34
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• 2014

일반적인 천연가스 정압기지에서는 압력제어밸브를 이용하여 고압으로 수송되는 천연가스를 감압하여 내보낸다. 이 과정에서 버려지는 폐압에너지는 터보팽창기를 도입하여 추가적인 전력생산이 가능하나 터보팽창기를 통과하는 유체에서는 감압에 의한 Joule Thompson 효과에 의하여 온도가 급격히 떨어져 파이프라인 외부에 동결을 일으키거나 파이프라인 내부에 메탄하이드레이트와 같은 고체 물질이 형성될 위험이 있다. 현재 터보팽창기를 채용한 천연가스 정압기지에서는 냉열발생에 따른 부작용을 방지하기 위하여 터보팽창기의 전단에 보일러를 설치하여 팽창 전 천연가스를 예열하고 있다. 용융탄산염연료전지와 같은 고온 연료전지는 천연가스를 연료로 사용할 수 있고 친환경적인 고온 배출가스를 방출하며 동시에 추가적인 전력을 생산하여 시스템의 효율을 높일 수 있다. 이 논문에서는 천연가스 정압기지에 용융탄산염연료전지와 터보팽창기를 설치하여 얻을 수 있는 열역학적 이득에 대해서 연구하였다. 연료전지를 기저부하로 사용함에 따라서 얻을 수 있는 이익에 대하여 분석하였다.

• 한국표면공학회지
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• 제31권1호
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• pp.3-11
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• 1998

Molten Carbonate Fuel cell is a promising new type electric power generation system which can achieve high efficiency, lower matrrial cost and high operating temperature Making internal reforming possible. Although the development of the MCEC is progressing rapidly toward commercialization, two important tchological problems such as dissolution of NiO cathode and not corrosion of metallic separator plate must be resolved. Because MCFC is operated at $650^{\circ}C$ and the electrolyte is very corrosive, corrosion-resistance of separator plated against oxidation abd molten carbonate is required. Al-coating on separator material for corrosion-resistance was carried out by painting, thermal spraying. hot dipping and vacuum vapour deposition. The corrosion of Al-coated STS 316S and 316L in molten carbonate at $700^{\circ}C$was studied. Vacuum vapour deposition and thermal spraing for Al-coating on STS 310S and 316L were the most effective methods for protecting thestainless steel corrosion in molten carbonate.

• Journal of Electrochemical Science and Technology
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• 제2권1호
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• pp.20-25
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• 2011

This work focuses on the behavior of the overpotential increase due to a utilization rise in a molten carbonate fuel cell. The behavior is generally explained by Nernst loss, which is a kind of voltage loss due to the thermodynamic potential gradients in a polarization state due to the concentration distribution of reactant species through the gas flow direction. The evaluation of Nernst loss is carried out with a traditional experimental method of constant gas utilization (CU). On the other hand, overpotential due to the gas-phase mass-transport resistance at the anode and cathode shows dependence on the utilization, which can be measured using the inert gas step addition (ISA) method. Since the Nernst loss is assumed to be due to the thermodynamic reasons, the voltage loss can be calculated by the Nernst equation, referred to as a simple calculation (SC) in this work. The three values of voltage loss due to CU, ISA, and SC are compared, showing that these values rise with increases in the utilization within acceptable deviations. When we consider that the anode and cathode reactions are significantly affected by the gas-phase mass transfer, the behavior strongly implies that the voltage loss is attributable not to thermodynamic reasons, namely Nernst loss, but to the kinetic reason of mass-transfer resistance in the gas phase.