Electrochemical Impedance Spectroscopy (EIS) Characterization of Reformate-operated High Temperature PEM Fuel Cell Stack

Sahlin, Simon Lennart; Araya, Samuel Simon; Andreasen, Søren Juhl; Kær, Søren Knudsen

doi:10.22606/ijper.2017.11003

Cited by 12 publications

(8 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The diameter of the impedance arc is the sum of the charge transfer and mass transfer resistance. The reduction in the arc diameter at higher temperatures indicates that there is a slight improvement in mass transport and high frequency charge transfer [ 49 ]. According to Su et al [ 50 ], an increase in temperature enhances the cell performance due to the increase in the mass transfer rate, and a lower cell resistance, as confirmed in this work.…”

Section: Resultsmentioning

confidence: 99%

“…According to Su et al [ 50 ], an increase in temperature enhances the cell performance due to the increase in the mass transfer rate, and a lower cell resistance, as confirmed in this work. Furthermore, the overall performance enhancement with increasing temperatures (polarization curves) can be attributed to the decrease in ohmic resistance and the improvement in mass transport and high frequency charge transfer observed in the EIS data [ 49 ].…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Hydrogen Separation and Purification from Various Gas Mixtures by Means of Electrochemical Membrane Technology in the Temperature Range 100–160 °C

2021

View full text Add to dashboard Cite

This paper reports on an experimental evaluation of the hydrogen separation performance in a proton exchange membrane system with Pt-Co/C as the anode electrocatalyst. The recovery of hydrogen from H2/CO2, H2/CH4, and H2/NH3 gas mixtures were determined in the temperature range of 100–160 °C. The effects of both the impurity concentration and cell temperature on the separation performance of the cell and membrane were further examined. The electrochemical properties and performance of the cell were determined by means of polarization curves, limiting current density, open-circuit voltage, hydrogen permeability, hydrogen selectivity, hydrogen purity, and cell efficiencies (current, voltage, and power efficiencies) as performance parameters. High purity hydrogen (>99.9%) was obtained from a low purity feed (20% H2) after hydrogen was separated from H2/CH4 mixtures. Hydrogen purities of 98–99.5% and 96–99.5% were achieved for 10% and 50% CO2 in the feed, respectively. Moreover, the use of proton exchange membranes for electrochemical hydrogen separation was unsuccessful in separating hydrogen-rich streams containing NH3; the membrane underwent irreversible damage.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Hydrogen Separation and Purification from Various Gas Mixtures by Means of Electrochemical Membrane Technology in the Temperature Range 100–160 °C

2021

View full text Add to dashboard Cite

show abstract

“…Shortly after, the load current was increased stepwise up to 6.35 A. The stoichiometry factor is based on the ratio between the available gas at the inlet and the required gas necessary for the reaction [32].…”

Section: Methodsmentioning

confidence: 99%

Characterization methodology for anode starvation in HT-PEM fuel cells

Yezerska

Dushina²,

Liu³

et al. 2019

International Journal of Hydrogen Energy

View full text Add to dashboard Cite

Degradation caused by fuel starvation may be an important reason for limited fuel cell lifetimes. In this work, we present an analytical characterization of the high temperature polymer exchange membrane fuel cell (HT-PEM FC) behavior under cycled anode starvation and subsequent regeneration conditions to investigate the impact of degradation due to H 2 starvation. Two membrane electrode assemblies (MEAs) with an active area of 21 cm 2 were operated of up to 550 minutes, which included up to 14 starvation / regeneration cycles. Overall cell voltage as well as current density distribution (S ++ unit) were measured simultaneously each minute during FC operation. The cyclicity of experiments was used to check the long term durability of the HT-PEM FC. After FC operation, micro-computed tomography (μ-CT) was applied to evaluate the influence of starvation on anode and cathode catalyst layer thicknesses.During starvation, cell voltage and current density distribution over the active area of the MEA significantly differed from nominal conditions. A significant drop in cell voltage from 0.6 to 0.1 V occured after approx. 20 minutes for the first starvation step, and after 10 minutes for all subsequent starvation steps. By contrast, the voltage response is immediately stable at 0.6 V during every regeneration step.During each starvation, the local current density reached up to 0.3 A•point -1 at the area near the gas inlet (9 cm 2 ) while near the outlet it drops to 0.01 A•point -1 . The deviation from a balanced current density distribution occurred after 10 minutes for the first starvation step, and after ca. 2 minutes for the subsequent starvation steps.Hence, compared to the voltage drop, the deviation from a balanced current density distribution always starts earlier. This indicates that the local current density distribution is more sensitive to local changes in the MEA than overal cell voltage drop. This finding may help to prevent undesirable influences of the starvation process.The μ-CT images showed that H 2 starvation lead to thickness decrease of ca. 20-30 % in both anode and cathode catalyst layers compared to a fresh MEA. Despite of the 14 starvation steps and the thinning of the catalyst layers the MEA presents stable cell voltage during regeneration.

show abstract

“…Note that this value is slightly higher than the one used in the experimental test and voltage values calculated by the model may slightly underestimate real values. However, in an experimental work performed in a similar short HT-PEMFC stack, it was found that once hydrogen starvation is avoided at around an anode stoichiometric ratio of 1.3, further increase in λ anode does not improve the fuel cell stack performance [41].…”

Section: System Modelingmentioning

confidence: 98%

System Design and Modeling of a High Temperature PEM Fuel Cell Operated with Ammonia as a Fuel

et al. 2020

Self Cite

View full text Add to dashboard Cite

Ammonia is a hydrogen-rich compound that can play an important role in the storage of green hydrogen and the deployment of fuel cell technologies. Nowadays used as a fertilizer, NH3 has the right peculiarities to be a successful sustainable fuel for the future of the energy sector. This study presents, for the first time in literature, an integration study of ammonia as a hydrogen carrier and a high temperature polymer electrolyte membrane fuel cell (HT-PEMFC) as an energy conversion device. A system design is presented, that integrates a reactor for the decomposition of ammonia with an HT-PEMFC, where hydrogen produced from NH3 is electrochemically converted into electricity and heat. The overall system based on the two technologies is designed integrating all balance of plant components. A zero-dimensional model was implemented to evaluate system efficiency and study the effects of parametric variations. Thermal equilibrium of the decomposition reactor was studied, and two different strategies were implemented in the model to guarantee thermal energy balance inside the system. The results show that the designed system can operate with an efficiency of 40.1% based on ammonia lower heating value (LHV) at the fuel cell operating point of 0.35 A/cm2 and 0.60 V.

show abstract

Electrochemical Impedance Spectroscopy (EIS) Characterization of Reformate-operated High Temperature PEM Fuel Cell Stack

Cited by 12 publications

References 31 publications

Hydrogen Separation and Purification from Various Gas Mixtures by Means of Electrochemical Membrane Technology in the Temperature Range 100–160 °C

Hydrogen Separation and Purification from Various Gas Mixtures by Means of Electrochemical Membrane Technology in the Temperature Range 100–160 °C

Characterization methodology for anode starvation in HT-PEM fuel cells

System Design and Modeling of a High Temperature PEM Fuel Cell Operated with Ammonia as a Fuel

Contact Info

Product

Resources

About