scholarly journals Membrane Electrolyte Assembly Health Estimation Method for Proton Exchange Membrane Fuel Cells

Author(s):  
Alexander J. Headley ◽  
Martha Gross ◽  
Dongmei Chen

Membrane electrolyte assembly (MEA) aging is a major concern for deployed proton exchange membrane (PEM) fuel cell stacks. Studies have shown that working conditions, such as the operating temperature, humidity, and open circuit voltage (OCV), have a major effect on degradation rates and also vary significantly from cell to cell. Individual cell health estimations would be very beneficial to maintenance and control schemes. Ideally, estimations would occur in response to the applied load to avoid service interruptions. To this end, this paper presents the use of an extended Kalman filter (EKF) to estimate the effective membrane surface area (EMSA) of each cell using cell voltage measurements taken during operation. The EKF method has a low computational cost and can be applied in real time to estimate the EMSA of each cell in the stack. This yields quantifiable data regarding cell degradation. The EKF algorithm was applied to experimental data taken on a 23-cell stack. The load profiles for the experiments were based on the FTP-75 and highway fuel economy test (HWFET) standard drive cycle tests to test the ability of the algorithm to perform in realistic load scenarios. To confirm the results of the EKF method, low performing cells and an additional “healthy” cell were selected for scanning electron microscope (SEM) analysis. The images taken of the cells confirm that the EKF accurately identified problematic cells in the stack. The results of this study could be used to formulate online sate of health estimators for each cell in the stack that can operate during normal operation.

2019 ◽  
Author(s):  
Valentina Guccini ◽  
Annika Carlson ◽  
Shun Yu ◽  
Göran Lindbergh ◽  
Rakel Wreland Lindström ◽  
...  

The performance of thin carboxylated cellulose nanofiber-based (CNF) membranes as proton exchange membranes in fuel cells has been measured in-situ as a function of CNF surface charge density (600 and 1550 µmol g<sup>-1</sup>), counterion (H<sup>+</sup>or Na<sup>+</sup>), membrane thickness and fuel cell relative humidity (RH 55 to 95 %). The structural evolution of the membranes as a function of RH as measured by Small Angle X-ray scattering shows that water channels are formed only above 75 % RH. The amount of absorbed water was shown to depend on the membrane surface charge and counter ions (Na<sup>+</sup>or H<sup>+</sup>). The high affinity of CNF for water and the high aspect ratio of the nanofibers, together with a well-defined and homogenous membrane structure, ensures a proton conductivity exceeding 1 mS cm<sup>-1</sup>at 30 °C between 65 and 95 % RH. This is two orders of magnitude larger than previously reported values for cellulose materials and only one order of magnitude lower than Nafion 212. Moreover, the CNF membranes are characterized by a lower hydrogen crossover than Nafion, despite being ≈ 30 % thinner. Thanks to their environmental compatibility and promising fuel cell performance the CNF membranes should be considered for new generation proton exchange membrane fuel cells.<br>


Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3932
Author(s):  
Jie Song ◽  
Qing Ye ◽  
Kun Wang ◽  
Zhiyuan Guo ◽  
Meiling Dou

The development of high efficient stacks is critical for the wide spread application of proton exchange membrane fuel cells (PEMFCs) in transportation and stationary power plant. Currently, the favorable operation conditions of PEMFCs are with single cell voltage between 0.65 and 0.7 V, corresponding to energy efficiency lower than 57%. For the long term, PEMFCs need to be operated at higher voltage to increase the energy efficiency and thus promote the fuel economy for transportation and stationary applications. Herein, PEMFC single cell was investigated to demonstrate its capability to working with voltage and energy efficiency higher than 0.8 V and 65%, respectively. It was demonstrated that the PEMFC encountered a significant performance degradation after the 64 h operation. The cell voltage declined by more than 13% at the current density of 1000 mA cm−2, due to the electrode de-activation. The high operation potential of the cathode leads to the corrosion of carbon support and then causes the detachment of Pt nanoparticles, resulting in significant Pt agglomeration. The catalytic surface area of cathode Pt is thus reduced for oxygen reduction and the cell performance decreased. Therefore, electrochemically stable Pt catalyst is highly desirable for efficient PEMFCs operated under cell voltage higher than 0.8 V.


2009 ◽  
Vol 187 (2) ◽  
pp. 324-331 ◽  
Author(s):  
Seiho Sugawara ◽  
Takao Maruyama ◽  
Yoshiki Nagahara ◽  
Shyam S. Kocha ◽  
Kazuhiko Shinohra ◽  
...  

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3478 ◽  
Author(s):  
Arne L. Lazar ◽  
Swantje C. Konradt ◽  
Hermann Rottengruber

This work presents an open-source, dynamic, 1D, proton exchange membrane fuel cell model suitable for real-time applications. It estimates the cell voltage based on activation, ohmic and concentration overpotentials and considers water transport through the membrane by means of osmosis, diffusion and hydraulic permeation. Simplified equations reduce the computational load to make it viable for real-time analysis, quick parameter studies and usage in complex systems like complete vehicle models. Two modes of operation for use with or without reference polarization curves allow for a flexible application even without information about cell parameters. The program code is written in MATLAB and provided under the terms and conditions of the Creative Commons Attribution License (CC BY). It is designed to be used inside of a Simulink model, which allows this fuel cell model to be used in a wide variety of 1D simulation platforms by exporting the code as C/C++.


Author(s):  
Chen-Chung Chung ◽  
Chiun-Hsun Chen ◽  
Hsiang-Hui Lin ◽  
Yi-Yie Yan

The investigation studies improving PEMFC carbon monoxide by a periodic air dosing. The carbon monoxide in the fuel gas leads to a significant loss in power density due to CO poisoning in the anode. The method involves bleeding air into the anode fuel stream (H2-CO), which contains CO in various concentrations (20, 52.7, 100 ppm). In the transient CO poisoning test, air-bleeding is performed for four different periodic air dosing and cell voltage is fixed at 0.6 V. The result of a dosing of air during 10 sec in intervals of 10 sec is similar to that of continuous air-bleeding except 100 ppm CO. The CO tolerance of the fuel cell and cell performance recovery from poisoning can be improved by air-bleeding.


2011 ◽  
Vol 306-307 ◽  
pp. 108-111
Author(s):  
Ai Ping Jin ◽  
Zhao Hui Wan ◽  
Kai Chen Lei

Charged Au nanoparticles with various diameters, from 2.7 nm to 10.3 nm, were synthesized by using various reducing agents. Then charged Au nanoparticles were self-assembled onto the NafionTM membrane surface as methanol barriers. It was found that the proton exchange membrane self-assembled with 3.9 nm Au particles had the lowest methanol crossover. The proton conductivity decreased with the increase of the particles size until the particles size was more than 6.2 nm and they had little influence on the membrane conductivity. All the self-assembled membranes have higher open circuit voltage (OCV) and performance than original Nafion212TM membrane. And the membranes self-assembled with 3.9 nm poly (diallymethylammonium chloride) (PDDA) modified Au (PDDA-Au) particles had the highest performance due to the reciprocal of the methanol permeation current density and membrane area resistance.


Sign in / Sign up

Export Citation Format

Share Document