• 한국수소및신에너지학회논문집
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• 제28권5호
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• pp.481-491
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• 2017

In this study, we developed 300 W lightweight DMFC system for charging secondary battery in small unit military operation. In order to reduce the volumetric shape and weight of the system considering the environment of the individual soldier's, the arranging of system components has been optimized. A metal bipolar plates made of STS-470FC have been implemented to the DMFC stack to meet the weight demand of the system. As a result of the performance test of the stack, the target value was satisfied by outputting 561 W exceeding 24% of the stack output 450 W required to output 300 W required for the entire system. Moreover, 2,655 hours exceeding 1,000 hours also has been satisfied. To ensure good robustness of the metallic bipolar plate based DMFC stack, finite element method based simulations are conducted using a commercial ANSYS Fluent software.

• Corrosion Science and Technology
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• 제21권5호
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• pp.340-347
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• 2022

In this research, mixed metal oxide (TiO₂, RuO₂) coating was applied to grade 1 titanium as a bipolar plate for polymer electrolyte membrane fuel cell (PEMFC). Electrochemical experiments were carried out in an aqueous solution of pH 3 (H₂SO₄ + 0.1 ppm HF, 80 ℃) determined by DoE. The air was bubbled to simulate a cathode environment. Potentiodynamic polarization test revealed that corrosion current densities of the titanium substrate and MMO-coated specimen were 0.180 µA/cm² and 4.381 µA/cm², respectively. There was no active peak. After potentiostatic experiment, current densities of the titanium substrate and the MMO-coated specimen were 0.19 µA/cm² and 1.05 µA/cm², respectively. As a result of observing the surface before and after the potentiostatic experiment, cracked dried clay structures were observed without corrosion damage. Both the titanium substrate and the MMO-coated specimen could not satisfy the interfacial contact resistance suggested by the DoE. Thus, further research is needed before they could be applied as bipolar plates.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.801-802
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• 2012

• 한국수소및신에너지학회논문집
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• 제13권4호
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• pp.313-320
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• 2002

The characteristics of the AISI bipolar plates have been investigated to replace the expensive graphite bipolar plates. It was found from the contact resistance evaluation of graphites, composites, and AISI that the contact resistance of AISI was the lowest, but it could approach to that of composites at higher compression forces. The single cell operation using the AISI bipolar plates revealed that the lower performance of the AISI single cell compared to the graphite one was due to not only the higher contact resistance but the flooding effect caused by high wettability of AISI. The performance of the AISI single cell could be improved if the channels were modified appropriately. The large size AISI single cell was operated to investigated the size effect on the performance.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.172-175
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• 2009

A bipolar plate is an important component in a fuel cell in the sense of cost and weight. This study aimed at developing highly conductive, lightweight, and low cost bipolar plates. Hybrid carbons filled poly(phenylene sulfide)(PPS) composite bipolar plates were prepared by using the compression molding technique. Various types and amounts of conducting carbon fillers such as graphite, carbon black, carbon fibers, and carbon nanotubes (CNTs) were adopted for the composites. Electrical conductivity and mechanical properties of the composites were measured in order to investigate effects of each components of fillers. When the graphite is only used as a conducting filler, the electrical conductivity of the composites increases with increasing the content, but the flexural strength decreases dramatically. However, for CNTs and carbon fibers, the flexural strength initially increases and then decreases with increasing the amount of the conducting fillers. The amount of graphite corresponding to the peak of flexural strength was moved to lower content with increasing the amount of CNTs or carbon fiber. When hybrid conducting fillers such as fibrous and particulate fillers were used, the synergy effect in mechanical and electrical properties was observed.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.133-136
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• 2007

In this work, 3-dimensional, non-isothermal numerical simulation was performed to analyse the effects of contact resistance and electric conductivity of GDL on the fuel cell performance. For numerical simulation contact resistance of Carbon and Stainless steel was measured. The simulation results reveal that 10 times change of electric conductivity leads only 6.5% decrease of PEMFC performance. But stainless steel which has high contact resistance decrease fuel cell performance over 25% at a high current density region than carbon. This results show that suitable Surface treatment technology is needed for metal bipolar plate, especially stainless steel.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2014년도 추계학술대회 논문집
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• pp.19-20
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• 2014

연료전지 스택을 구성하는 핵심 부품 중 하나인 분리판(Bipolar plate)은 반응 연료인 수소와 산소를 분리하여 셀(cell)의 전면적에 균일하게 분배, 공급, 배기 및 전기화학반응에 의해 생성된 전류를 수집하며, 높은 가스밀폐성, 전기전도성 및 내식성이 요구된다. 분리판 소재로는 흑연, 고분자-탄소 복합체 및 금속 등이 사용되고 있으며, 이중 연료전지 스택의 부피, 무게 및 제조비용 감소를 위하여 금속분리판이 주목받고 있다. 그러나 금속분리판의 경우 연료전지 작동환경에서 부식반응에 의한 이온 용출로 인해 전극촉매나 고분자전해질막의 오염을 유발할 수 있다는 단점이 있어 최근 금속계 분리판의 코팅을 통하여 분리판의 내식특성 및 전기적 특성을 향상시키는 연구가 활발히 진행되고 있다.

• 한국표면공학회지
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• 제45권4호
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• pp.162-167
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• 2012

Ni-P/C multi-layer was synthesized by electroless plating and paste coating for better corrosion and surface conductance as a metallic bipolar plate. The Ni-P layer could be synthesized with the range of 2.6~22.4 at.% P contents and it's surface morphology and corrosion resistance depend on content of P. Corrosion resistance of the Ni-P layer in sulfuric acid by electrochemical test is similar with pure Ni. Surface resistance of pure Ni after corrosion was increased about 8% compared to pure Ni. On the other hand, that of the Ni-P/C composite with 20% carbon content was increased only 1%.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1566-1571
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• 2003

The cold plate used for a CEU(Control Electronics Unit) of an EV(Electric Vehicle) is extremely important since the dissipation of the heat generated from power devices like IGBT(Insulated Gate Bipolar Transistor) and diode has a significant effect on the performance as well as the durability of the CED. The cold plate consists of seven power devices, and coolant flows through the passage bonded to a groove of the cold plate. In order to find out heat transfer and pressure drop characteristics, series of numerical analyses for the cold plate with enhanced coolant passages were conducted. Based on results of the numerical analyses, an improved model of the cold plate has been proposed. The experiments under the various conditions have been conducted to compare the performance of the proposed cold plate to the present one. As a result of the numerical analyses together with the experiments, the ideal design of the cold plate could be offered.

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 2002년도 추계총회 및 학술발표회
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• pp.64-64
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• 2002