Rod Borup is a Team Leader in the fuel cell program at Los Alamos National Lab in Los Alamos, New Mexico. He received his B.S.E. in Chemical Engineering from the University of Iowa in 1988 and his Ph.D. from the University of Washington in 1993. He has worked on fuel cell technology since 1994, working in the areas of hydrogen production and PEM fuel cell stack components. He has been awarded 12 U.S. patents, authored over 40 papers related to fuel cell technology, and presented over 50 oral papers at national meetings. His current main research area is related to water transport in PEM fuel cells and PEM fuel cell durability. Recently, he was awarded the 2005 DOE Hydrogen Program R&D Award for the most significant R&D contribution of the year for his team's work in fuel cell durability and was the Principal Investigator for the 2004 Fuel Cell Seminar (San Antonio, TX, USA) Best Poster Award. Jeremy Meyers is an Assistant Professor of materials science and engineering and mechanical engineering at the University of Texas at Austin, where his research focuses on the development of electrochemical energy systems and materials. Prior to joining the faculty at Texas, Jeremy workedmore » as manager of the advanced transportation technology group at UTC Power, where he was responsible for developing new system designs and components for automotive PEM fuel cell power plants. While at UTC Power, Jeremy led several customer development projects and a DOE-sponsored investigation into novel catalysts and membranes for PEM fuel cells. Jeremy has coauthored several papers on key mechanisms of fuel cell degradation and is a co-inventor of several patents. In 2006, Jeremy and several colleagues received the George Mead Medal, UTC's highest award for engineering achievement, and he served as the co-chair of the Gordon Research Conference on fuel cells. Jeremy received his Ph.D. in Chemical Engineering from the University of California at Berkeley and holds a Bachelor's Degree in Chemical Engineering from Stanford University. Bryan Pivovar received his B.S. in Chemical Engineering from the University of Wisconsin in 1994. He completed his Ph.D. in Chemical Engineering at the University of Minnesota in 2000 under the direction of Profs. Ed Cussler and Bill Smyrl, studying transport properties in fuel cell electrolytes. He continued working in the area of polymer electrolyte fuel cells at Los Alamos National Laboratory as a post-doc (2000-2001), as a technical staff member (2001-2005), and in his current position as a team leader (2005-present). In this time, Bryan's research has expanded to include further aspects of fuel cell operation, including electrodes, subfreezing effects, alternative polymers, hydroxide conductors, fuel cell interfaces, impurities, water transport, and high-temperature membranes. Bryan has served at various levels in national and international conferences and workshops, including organizing a DOE sponsored workshop on freezing effects in fuel cells and an ARO sponsored workshop on alkaline membrane fuel cells, and he was co-chair of the 2007 Gordon Research Conference on Fuel Cells. Minoru Inaba is a Professor at the Department of Molecular Science and Technology, Faculty of Engineering, Doshisha University, Japan. He received his B.Sc. from the Faculty of Engineering, Kyoto University, in 1984 and his M.Sc. in 1986 and his Dr. Eng. in 1995 from the Graduate School of Engineering, Kyoto University. He has worked on electrochemical energy conversion systems including fuel cells and lithium-ion batteries at Kyoto University (1992-2002) and at Doshisha University (2002-present). His primary research interest is the durability of polymer electrolyte fuel cells (PEFCs), in particular, membrane degradation, and he has been involved in NEDO R&D research projects on PEFC durability since 2001. He has authored over 140 technical papers and 30 review articles. Kenichiro Ota is a Professor of the Chemical Energy Laboratory at the Graduate School of Engineering, Yokohama National University, Japan. He received his B.S.E. in Applied Chemistry from the University of Tokyo in 1968 and his Ph.D. from the University of Tokyo in 1973. He has worked on hydrogen energy and fuel cells since 1974, working on materials science for fuel cells and water electrolysis. He has published more than 150 original papers, 70 review papers, and 50 scientific books. He is now the president of the Hydrogen Energy Systems Society of Japan, the chairman of the Fuel Cell Research Group of the Electrochemical Society of Japan, and the chairman of the National Committee for the Standardization of the Stationary Fuel Cells. ABSTRACT TRUNCATED« less

Scientific aspects of polymer electrolyte fuel cell durability and degradation.

Electrochemical impedance spectroscopy (EIS) is a powerful tool to investigate properties of materials and electrode reactions. This Primer provides a guide to the use of EIS with a comparison to other electrochemical techniques. The analysis of impedance data for reduction of ferricyanide in a KCl supporting electrolyte is used to demonstrate the error structure for impedance measurements, the use of measurement and process models, as well as the sensitivity of impedance to the evolution of electrode properties. This Primer provides guidelines for experimental design, discusses the relevance of accuracy contour plots to wiring and instrumentation selection, and emphasizes the importance of the Kramers-Kronig relations to data validation and analysis. Applications of EIS to battery performance, metal and alloy corrosion, and electrochemical biosensors are highlighted. Electrochemical impedance measurements depend on both the mechanism under investigation and extrinsic parameters, such as the electrode geometry. Experimental complications are discussed, including the influence of nonstationary behaviour at low frequencies and the need for reference electrodes. Finally, emerging trends in experimental and interpretation approaches are also described.

/pdf/electrochemical-impedance-spectroscopy-3e6x9qlxk6.pdf

Electrochemical Impedance Spectroscopy

In this comprehensive review, recent progress and developments on perfluorinated sulfonic-acid (PFSA) membranes have been summarized on many key topics. Although quite well investigated for decades, PFSA ionomers’ complex behavior, along with their key role in many emerging technologies, have presented significant scientific challenges but also helped create a unique cross-disciplinary research field to overcome such challenges. Research and progress on PFSAs, especially when considered with their applications, are at the forefront of bridging electrochemistry and polymer (physics), which have also opened up development of state-of-the-art in situ characterization techniques as well as multiphysics computation models. Topics reviewed stem from correlating the various physical (e.g., mechanical) and transport properties with morphology and structure across time and length scales. In addition, topics of recent interest such as structure/transport correlations and modeling, composite PFSA membranes, degradat...

New Insights into Perfluorinated Sulfonic-Acid Ionomers

https://faculty.kfupm.edu.sa/che/zaidismj/publications/membranes_heteropolyacids_fuelcells_memb.pdf

Proton conducting composite membranes from polyether ether ketone and heteropolyacids for fuel cell applications

Polymer membranes for high temperature proton exchange membrane fuel cell : recent advances and challenges

Nafion 117{reg_sign} is a proton conducting ion-exchange membrane which is now receiving much attention due to its use as an electrolyte in the polymer-electrolyte-membrane fuel cell (PEMFC), which is of great interest for electric vehicle propulsion. The proton conductivity of Nafion 117 was measured under various conditions of humidity and temperature using a four-electrode ac impedance method. The conductivity of this membrane without heat-treatment was ca. 7.8 {times} 10{sup {minus}2} S/cm at ambient temperature and 100% relative humidity; it varied strongly with the humidity and heat-treatment of the membrane. After heat-treatment, the membrane showed a slight dependence of conductivity on temperature. From 21 to 45 C, its conductivity at a given relative humidity decreased with increasing temperature, while from 45 to 80 C it increased with temperature.

https://iopscience.iop.org/article/10.1149/1.1836625/pdf

Proton Conductivity of Nafion 117 as Measured by a Four‐Electrode AC Impedance Method

The mechanism of the hydrogen evolution reaction on the amorphous metals and in at has been studied by electrochemical impedance spectroscopy in the frequency range . Comparative measurements were carried out on polycrystalline Ni and Pt electrodes. Analysis and discussion of the data is based on a theoretical transfer function derived for the Volmer‐Tafel reaction mechanism. Formal rate constants could be obtained from a nonlinear least squares fit of the impedance data and were compared with previous results obtained from an analysis of steady‐state polarization curves. Participation of surface and/or bulk diffusion steps of H atoms at low overpotentials is indicated on by a time constant arising at low frequencies in the impedance spectra.

https://iopscience.iop.org/article/10.1149/1.2086034/pdf

Per Ekdunge

Papers

Proton Conductivity of Nafion 117 as Measured by a Four‐Electrode AC Impedance Method

Electrochemical Impedance Study on the Kinetics of Hydrogen Evolution at Amorphous Metals in Alkaline Solution

Processes at the micro-level in the oxidation of PbSO4 to PbO2 during charging of lead/acid battery positive plates

A simplified model of the lead/acid battery

Recharge Kinetics of the Porous Lead Dioxide Electrode I . The Effect of Structural Changes