In Situ Measurements of Through-Plane, Ionic Potential Distributions in Porous Electrodes

2010 ◽  
Author(s):  
Katherine C. Hess ◽  
William K. Epting ◽  
Shawn Litster
Keyword(s):  
Polymer Electrolyte Membrane ◽  
Porous Electrode ◽  
Catalyst Layer ◽  
In Situ Measurements ◽  
Porous Electrodes ◽  
Ionic Potential ◽  
Electrolyte Membrane ◽  
Insight Into

We present a novel apparatus for gathering in situ measurements of through-plane, ionic potential distributions in the porous electrodes of a polymer electrolyte membrane (PEM) fuel cell. Our diagnostic method uses a micro-structured electrode scaffold (MES) that is comprised of alternating layers of insulating and sensing materials into which a 100 μm diameter hole is micro-milled and then filled with catalyst ink. Using the MES, we performed a polarization curve experiment where the ionic potential was measured within a 50 μm thick catalyst layer at 8 and 24 μm from membrane. Our results show that there are significant ionic potential variations within the electrode. Such data is valuable in the electrochemical characterization of electrodes and catalysts. The MES potential measurements also provide insight into reaction distributions across the thickness of the electrode, which is valuable in the validation of porous electrode models.

scholarly journals Parameter Identification of a Quasi-3D PEM Fuel Cell Model by Numerical Optimization

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1808
Author(s):  
Maximilian Haslinger ◽  
Christoph Steindl ◽  
Thomas Lauer
Keyword(s):  
Numerical Optimization ◽  
Cell Model ◽  
Polymer Electrolyte Membrane ◽  
Catalyst Layer ◽  
Transient Behavior ◽  
Simplex Algorithm ◽  
Gas Diffusion ◽  
Material Parameters ◽  
Electrolyte Membrane

Polymer electrolyte membrane fuel cells (PEMFCs) supplied with green hydrogen from renewable sources are a promising technology for carbon dioxide-free energy conversion. Many mathematical models to describe and understand the internal processes have been developed to design more powerful and efficient PEMFCs. Parameterizing such models is challenging, but indispensable to predict the species transport and electrochemical conversion accurately. Many material parameters are unknown, or the measurement methods required to determine their values are expensive, time-consuming, and destructive. This work shows the parameterization of a quasi-3D PEMFC model using measurements from a stack test stand and numerical optimization algorithms. Differential evolution and the Nelder–Mead simplex algorithm were used to optimize eight material parameters of the membrane, cathode catalyst layer (CCL), and gas diffusion layer (GDL). Measurements with different operating temperatures and gas inlet pressures were available for optimization and validation. Due to the low operating temperature of the stack, special attention was paid to the temperature dependent terms in the governing equations. Simulations with optimized parameters predicted the steady-state and transient behavior of the stack well. Therefore, valuable data for the characterization of the membrane, the CCL and GDL was created that can be used for more detailed CFD simulations in the future.

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