Dear Colleagues,
Greetings! The week’s digital digest features four papers in the use of novel techniques to better understand PEM fuel cells and electrolyzers.
Measuring the effective gas diffusivity using a microfluidic device. Suzuki and coworkers employed a unique microfluidic device to determine the effective gas diffusivity and tortuosity factor of PEMFC catalyst layers. Catalyst layers with different thicknesses and different carbon supports were evaluated. Carbon black and multi-walled carbon nanotubes were blended into the catalyst layers as the support to vary the porous structures (porosity, pore size and pore connection) (Contact author: Takahiro Suzuki at suzuki@mech.eng.osaka-u.ac.jp)
In-plane mass transport in a water electrolyzer. Kim et al. used in-operando X-ray radiography and electrochemical performance analysis to determine and better understand the mass transport in the porous layer of a PEM water electrolyzer. They observed that pores in the through-plane direction inhibited in-plane mass transport in both the porous layer and the catalyst layer such that the pores under the lands were inaccessible to liquid water, leading to an under-utilized active area and inferior electrochemical performance. Several recommendations were proposed by the authors to achieve high-performance water electrolysis. (Contact author: Aimy Bazylak at abazylak@mie.utoronto.ca).
Accelerated stress test protocols to simulate reversal events in PEMFCs. Marić and coworkers reported the design of different accelerated stress test protocols by varying the duration of H2-starvation pulses. Understanding and mitigation H2-starvation in a PEMFC are of significance in improving PEMFC durability. Shortening the pulse duration was found to accompany higher carbon corrosion currents and greater ECSA loss in the anode, whereas the ECSA of the cathode was nearly unaffected. Possible mechanisms were discussed to understand the performance degradation driven primarily by an increased ohmic resistance. (Contact authors: Frédéric Hasché at f.hasche@tu-braunschweig.de and Peter Strasser at pstrasser@tu-berlin.de)
Electrode wettability in CO2 electrozlyers. In the electrochemical conversion of CO2 to liquid products, flooding can be a challenging problem that limits the performance and decreases the durability of vapor-fed reactors. Leonard and coworkers investigated the flooding issue originated from the high concentrations of liquid products with low surface tension, thus an increase in wettability of gas diffusion electrodes. By combining sessile drop contact angle measurements, electrolyzer mass balances, and capillary pressure models, they were able to map liquid product compositions to cell operating conditions. Strategies to engineer better electrodes were proposed for the scale-up manufacturing. (Contact Author: Fikile R. Brushett at brushett@mit.edu).
On behalf of the Associate Editors, Professors Ray Gorte, Thomas Schmidt, and Minhua Shao, I would like to thank all authors for their contributions and thank all reviewers for their insightful comments which made the following publications possible.
With best regards,
Xiao-Dong Zhou
Fuel Cells, Electrolyzers, and Energy Conversion Technical Editor
Journal of The Electrochemical Society
Journal of The Electrochemical Society
Investigation of Gas Transport Properties of PEMFC Catalyst Layers Using a Microfluidic Device
Takahiro Suzuki, Yasuhiro Nakata, Fumiaki Tsutsui, and Shohji Tsushima
Read now | Open access
In-Plane Transport in Water Electrolyzer Porous Transport Layers with Through Pores
P. J. Kim, CH. Lee, J. K. Lee, K.F. Fahy, and A. Bazylak
Read now | Open access
Towards a Harmonized Accelerated Stress Test Protocol for Fuel Starvation Induced Cell Reversal Events in PEM Fuel Cells: The Effect of Pulse Duration
Robert Marić, Christian Gebauer, Markus Nesselberger, Frédéric Hasché, and Peter Strasser
Read now | Open access
Editors' Choice—Flooded by Success: On the Role of Electrode Wettability in CO2 Electrolyzers that Generate Liquid Products
McLain E. Leonard, Michael J. Orella, Nicholas Aiello, Yuriy Román-Leshkov, Antoni Forner-Cuenca, and Fikile R. Brushett
Read now | Open access