Effect of operating conditions on current density distribution and high frequency resistance in a segmented PEM fuel cell

2012 ◽  
Vol 37 (9) ◽  
pp. 7736-7744 ◽  
Author(s):  
Dietmar Gerteisen ◽  
Nada Zamel ◽  
Christian Sadeler ◽  
Florian Geiger ◽  
Victor Ludwig ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Density Distribution ◽  
Current Density ◽  
High Frequency ◽  
Current Density Distribution ◽  
Pem Fuel Cell ◽  
Operating Conditions

Effects of Operating Parameters on the Current Density Distribution in Proton Exchange Membrane Fuel Cells

2006 ◽  
Vol 3 (4) ◽  
pp. 464-476 ◽  
Author(s):  
Y. Zhang ◽  
A. Mawardi ◽  
R. Pitchumani
Keyword(s):  
Fuel Cell ◽  
Density Distribution ◽  
Current Density ◽  
Proton Exchange Membrane ◽  
Current Density Distribution ◽  
Pem Fuel Cell ◽  
Proton Exchange ◽  
Operating Conditions ◽  
Local Current Density ◽  
Local Current

During the operation of a proton exchange membrane (PEM) fuel cell, significant variation of the local current density could exist across the cell causing sharp temperature and stress gradients in certain points, and affecting the water management, all of which severely impact the cell performance and reliability. The variation of local current density is a critical issue in the performance of PEM fuel cell, and is influenced by the operating conditions. This article presents a model-assisted parametric design with the objective of determining the operating conditions which maximize the fuel cell performance while maintaining a level of uniformity in the current density distribution. A comprehensive two-dimensional model is adopted to simulate the species transport and electrochemical phenomena in a PEM fuel cell. Numerical simulations are performed for over a wide range of operating conditions to analyze the effects of various operating parameters on the variation of local current density of the fuel cell, and to develop design windows which serve as guideline in the design for maximum power density, minimum reactant stoichiometry, and uniform current density distribution.

Dynamic Behavior and In-Situ Diagnostics of PEFCs

2006 ◽  
Author(s):  
Kaspar Andreas Friedrich ◽  
Till Kaz ◽  
Stefan Scho¨nbauer ◽  
Heinz Sander
Keyword(s):  
Fuel Cell ◽  
Density Distribution ◽  
Current Density ◽  
Single Cells ◽  
Current Density Distribution ◽  
Bipolar Plate ◽  
Life Cycles ◽  
Operating Conditions ◽  
Bipolar Plates

During fuel cell operation the electrochemical activity often is not homogenous over the electrode area. This may be caused by an non-uniform water content in the membrane, an inhomogeneous temperature distribution, and reactant gradients in the cell. Consequently a variation of the current density over the cell area occurs which tends to result in inferior performance. For in situ measurements of the current density distribution in fuel cell stacks a segmented bipolar plate was developed. The segmented bipolar plate was first tested in single cells with stack endplates to verify the function of all components. The tests showed that the measurement tool works very reliable and accurate. The insight in an operating fuel cell stack via current density distribution measurement is very helpful to investigate interactions between cells. Results can be used to validate models and to optimise stack components, e.g. flow field and manifold design, as well as to detect the best stack operating conditions. By applying segmented bipolar plates as sensor plates for stack system controls an improved performance, safe operation and longer life cycles can be achieved. The developed segmented bipolar plates with integrated current sensors were used to assemble a short stack consisting of 3 cells; each of them having an active area of 25cm2 divided into 49 segments. The design of the bipolar plate proofed very suitable for easy assembling of single cells and stacks. First measurement results show that different current distributions can appear in the cells and these can vary from cell to cell, depending on the operating conditions of the stack. Electrical coupling between the cells was investigated and found to be only marginal for the assembly used.

Analysis of Single PEM Fuel Cell Performances Based on Current Density Distribution Measurement

2005 ◽  
Vol 3 (3) ◽  
pp. 351-357 ◽  
Author(s):  
P. C. Ghosh ◽  
T. Wüster ◽  
H. Dohle ◽  
N. Kimiaie ◽  
J. Mergel ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Density Distribution ◽  
Current Density ◽  
Operating Temperature ◽  
Current Density Distribution ◽  
Polymer Electrolyte Fuel Cells ◽  
Operating Conditions ◽  
Cathode Side ◽  
Gas Pressures

A new in situ measurement method of mapping the current density distribution in polymer electrolyte fuel cells (PEFC) is used to analyze the performance of a fuel cell under different operating conditions. The present method is useful in investigating the current density distribution in a single cell as well as a stack, which carries the information about the local reactant activity over the electrode area. It was found that the current density close to the gas inlets is strongly influenced by the reactants' relative humidity. The performance close to the gas outlets is greatly influenced by the inlet gas pressures and the stoichiometry factors of the reactant gases, mainly on the cathode side. It was also observed that the performance of the fuel cell drops with the increase in operating temperature if the reactant gases are not sufficiently humidified.

Current density distribution in an HT-PEM fuel cell with a poly (2, 5-benzimidazole) membrane

2021 ◽  
Vol 46 (3) ◽  
pp. 3022-3031
Author(s):  
Mingfu Yu ◽  
Hong Sun ◽  
Tianyu Zhang ◽  
Qiang Li ◽  
Jie Li ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Density Distribution ◽  
Current Density ◽  
Current Density Distribution ◽  
Pem Fuel Cell

Experiment Study on the Current Density Distribution of PEMFC by Segmented Cell Technology

2020 ◽  
Author(s):  
Tianwei Miao ◽  
Xu Xie ◽  
Chasen Tongsh ◽  
Jinqiao Liang ◽  
Yiqi Liang ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Density Distribution ◽  
Current Distribution ◽  
Current Density ◽  
Proton Exchange Membrane ◽  
Current Density Distribution ◽  
Cold Start ◽  
Proton Exchange ◽  
Cell Technology ◽  
Segmented Cell

Abstract The homogeneous of current density distribution is very important for performance and lifetime of proton exchange membrane fuel cell. In this study the current density distribution of a fuel cell with an active area of 108 cm2 has been investigated by using segmented cell technology. The σc is introduced to evaluate the homogeneity of current density and the smaller value of σc represents better homogeneity of current distribution. Under normal conditions, the experimental results show that the current density decreases progressively along the flow field at low cathode stoichiometry. It is also found that the homogeneity of current distribution has a strong correlation with the membrane hydration condition and always performs best at cathode relative humidity of 80% when anode condition keeps constant. The value of σc can be significantly reduced when cathode stoichiometry increases from 1.5 to 2.5, but it changes little when cathode stoichiometry continues to increase. During the cold start process, the evolutions of current density distribution are consistent with the temperature mappings. The form of stabilized heat core in the middle regions and homogeneous current density distribution are necessary for successful cold start. The value of σc also can be used to evaluate that the cold start succeeds or not.

Sign in / Sign up

Export Citation Format

Share Document