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Suncheon, South Korea

Jeong J.-H.,Sunchon National University | Song M.-H.,Sunchon National University | Chung H.-B.,Sunchon National University | Lee M.-S.,Sunchon National University | And 8 more authors.
Korean Chemical Engineering Research | Year: 2015

Recently, direct formic acid fuel cells (DFAFC) among direct liquid fuel cells is studied actively. Economical hydrocarbon membranes alternative to fluorinated membranes for DFAFC's membrane are receiving attention. In this study, characteristics of sulfonated poly(ether ether ketone, sPEEK) and sulfonated poly(arylene ether sulfone, PAES) membranes were compared with Nafion membrane at DFAFC operation condition. Formic acid crossover current density of hydrocarbon membranes were lower than that of Nafion 211 fluorinated membrane. I-V performance of sPEEK MEA(Membrane and Electrode Assembly) was similar to that of Nafion 211 MEA due to similar membrane resistance each other. sPEEK MEA with low formic acid crossover showed higher stability compared with Nafion 211 MEA.

Lee S.-H.,Sunchon National University | Hwang B.-C.,Sunchon National University | Lee H.-R.,Sunchon National University | Kim Y.-S.,Sunchon National University | And 5 more authors.
Korean Chemical Engineering Research | Year: 2015

Enzyme fuel cells were operated with cells composed of enzyme anode and PEMFC cathode. Enzyme anodes was fabricated by compression of a mixture of graphite particle, glucose oxidase(Gox) as a enzyme and ferrocene as a redox mediator, and then coated with Nafion ionomer solution. Performances of enzyme unit cell were measured with variation of anode manufacture factors, to find optimum condition of enzyme anode. Optimum pressure was 8.89MPa for enzyme anode pressing process. Highest power density was obtained at 60% graphite composition in enzyme anode. Optimum glucose concentration was 1.7 mol/l in anode substrate solution. The enzyme anode was stabilized by two times of deeping in Nafion solution for 1 sec.

Jung H.-S.,Sunchon National University | Jo B.-J.,Sunchon National University | Lee J.-H.,CNL Energy Co | Lee H.-J.,CNL Energy Co | And 3 more authors.
Korean Chemical Engineering Research | Year: 2016

Proton Exchange Membrane Fuel Cells (PEMFC) instead of batteries is appropriate for long time flight of unmanned aero vehicles (UAV). In this work, NaBH4 hydrolysis system supplying hydrogen to PEMFC was studied. In order to decrease weight of NaBH4 hydrolysis system, enhancement of hydrogen yield, recovery of condensing water and maintenance of stable hydrogen yield were studied. The hydrogen yield of 3.4% was increased by controlling of hydrogen pressure in hydrolysis reactor. Condensing water formed during air cooling of hydrogen was recovered into storage tank of NaBH4 solution. In this process the condensing water dissolved NaBH4 powder and then addition of NaBH4 solution decreased system weight of 14%. NaBH4 hydrolysis system was stably operated with hydrogen yield of 96% by 2.0g Co-P-B catalyst for 10 hours at 2.0L/min hydrogen evolution rate.

Lee H.-R.,Sunchon National University | Lee S.-H.,Sunchon National University | Hwang B.-C.,Sunchon National University | Na I.-C.,CNL Energy Co | And 3 more authors.
Korean Chemical Engineering Research | Year: 2016

Recently, there are many efforts focused on development of more economical non-fluorinated membranes for PEMFCs (Proton Exchange Membrane Fuel Cells). In this study, to test the durability of sPEEK MEA (Membrane and Electrode Assembly), ADT (Accelerated Degradation Test) of MEA degradation was done at the condition that membrane and electrode were degraded simultaneously. Before and after degradation, I-V polarization curve, hydrogen crossover, electrochemical surface area, membrane resistance and charge transfer resistance were measured. Although the permeability of hydrogen through sPEEK membrane was low, sPEEK membrane was weaker to radical evolved at low humidity and OCV condition than fluorinated membrane such as Nafion. Performance after MEA degradation for 144 hours and 271 hours were reduced by 15% and 65%, respectively. It was showed that the main cause of rapid decrease of performance after 144 hours was shorting due to Pt/C particles in the pinholes.

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