Degradation mechanisms and mitigation strategies of metal cations in recycled fuel for direct methanol fuel cell membrane electrode assembly

• Published in: Journal of power sources Vol. 242; pp. 646 - 655
• Main Authors: Yang, Min-Jee, Park, Ka-Young, Kim, Ki-Beum, Cho, Hyejung, Choi, Hanshin, Park, Jun-Young
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15-11-2013; Elsevier
• Subjects: Analytical chemistry; Applied sciences; Assembly; Cations; Chemistry; Chromatographic methods and physical methods associated with chromatography; Contaminants; Degradation; Direct energy conversion and energy accumulation; Direct methanol fuel cells; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Electrodes; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Fuel cells; Fuel impurity; Fuels; Ion-exchange resin; Membrane electrode assembly; Methyl alcohol; Mitigation; Other chromatographic methods; Mitigation; Direct methanol fuel cells; Membrane electrode assembly; Ion-exchange resin; Fuel impurity; Impurity; Purity control; Metal ion; Alcohol fuel cells; Mechanism; Primary alcohol; Ion exchange chromatography; Degradation; Quality control; Recycling; Adsorbent; Ion exchange resin; Damaging; Methanol; Stationary phase
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2013.05.141

Some metal contaminants, such as Al3+, Ni+2, Fe2+ and Cr3+, are produced during reactions in heat exchangers, stacks, and other fuel/water management system components. Due to the gradual build-up of these contaminants generated in the system, direct methanol fuel cell (DMFC) membrane electrode assemblies (MEAs) deteriorate steadily with increasing operation time. Hence, this study systematically investigates the effects of metal cations by supplying various concentrations of metal solutions to the fuel stream at constant-current densities, with the aim of understanding the mechanism and influence of metal contamination on a DMFC MEA. Various electrochemical diagnostic techniques are used to determine the main cause of MEA degradation, including electrochemical impedance spectroscopy, electrode polarization, and methanol stripping voltammetry. In addition, the critical concentration of metal cations in methanol fuel is investigated for high DMFC MEA stability. Further, various novel methods for mitigating the influence of the metal contaminants on the performance of a DMFC are suggested and verified.
•Investigated the effects of metal cations in the fuel stream of DMFC.•Determined the main cause of MEA degradation in the fuel contamination.•Investigated the critical concentration of metal cations in methanol fuel.•Tested various novel methods for mitigating the influence of metal contaminants.