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1.
A review of polymer electrolyte membrane fuel cell stack testing 总被引:2,自引:0,他引:2
This paper presents an overview of polymer electrolyte membrane fuel cell (PEMFC) stack testing. Stack testing is critical for evaluating and demonstrating the viability and durability required for commercial applications. Single cell performance cannot be employed alone to fully derive the expected performance of PEMFC stacks, due to the non-uniformity in potential, temperature, and reactant and product flow distributions observed in stacks. In this paper, we provide a comprehensive review of the state-of-the art in PEMFC testing. We discuss the main topics of investigation, including single cell vs. stack-level performance, cell voltage uniformity, influence of operating conditions, durability and degradation, dynamic operation, and stack demonstrations. We also present opportunities for future work, including the need to verify the impact of stack size and cell voltage uniformity on performance, determine operating conditions for achieving a balance between electrical efficiency and flooding/dry-out, meet lifetime requirements through endurance testing, and develop a stronger understanding of degradation. 相似文献
2.
Jin Young Park Yeong Ho Lee In Seop Lim Young Sang Kim Min Soo Kim 《International Journal of Hydrogen Energy》2021,46(39):20678-20692
In the development process of a fuel cell, understanding the local current distribution is essentially required to achieve better performance and durability. Therefore, many developers apply a segmented fuel cell to observe current distribution under various operating conditions. With the application, experimental data is collected. This study suggests a utilization method for this collected data to develop a local current prediction model. The details of this neural network-based prediction model are introduced, including the pretreatment of the data. In the pretreatment process, current residual values are used for better prediction performance. As a result, the model predicted local current values with a 2.98% error. With the model, the effects of pressure, temperature, cathode relative humidity, and cathode flow rate on local current distribution trends are analyzed. Since the non-uniform current distribution of a fuel cell often leads to low performances or fast local degradation, the optimal operating condition to achieve current uniformity is acquired with an additional model. This model is developed by switching inputs and outputs of the local current prediction model. With the model application, the uniform current distribution is achieved with a standard deviation of 0.039 A/cm2 under the current load at 1 Acm?2. 相似文献
3.
Comparative studies of polymer electrolyte membrane fuel cell stack and single cell 总被引:10,自引:0,他引:10
The polymer electrolyte membrane fuel cell (PEMFC) was investigated comparatively as a single cell and a 30-cell stack. Various types of Nafion membranes, such as Nafion 117, 115, 112 and 105, were tested as electrolyte within the single cell and at different temperatures, among which Nafion 112 gave the optimal result. The 30-cell stack was evaluated at different humidities and temperatures. The potential–current and power–current curves, both for single cell and the stack, were analyzed by computer simulation, whereby the kinetic and mass-transfer parameters were calculated. The long-term performance of the stack and the water production during long-term operation were also measured. 相似文献
4.
Philip L. Hentall J. Barry Lakeman Gary O. Mepsted Paul L. Adcock Jon M. Moore 《Journal of power sources》1999,80(1-2):235-241
Polymer Electrolyte Membrane Fuel cells for automotive applications need to have high power density, and be inexpensive and robust to compete effectively with the internal combustion engine. Development of membranes and new electrodes and catalysts have increased power significantly, but further improvements may be achieved by the use of new materials and construction techniques in the manufacture of the bipolar plates. To show this, a variety of materials have been fabricated into flow field plates, both metallic and graphitic, and single fuel cell tests were conducted to determine the performance of each material. Maximum power was obtained with materials which had lowest contact resistance and good electrical conductivity. The performance of the best material was characterised as a function of cell compression and flow field geometry. 相似文献
5.
Hsiao-Kuo HsuenKen-Ming Yin 《Journal of power sources》2011,196(1):218-227
A mathematical formulation for the cathode of a membrane electrode assembly of a polymer electrolyte membrane fuel cell is proposed, in which the effect of unsaturated vapor feed in the cathode is considered. This mechanistic model formulates the water saturation front within the gas diffusion layer with an explicit analytical expression as a function of operating conditions. The multi-phase flows of gaseous species and liquid water are correlated with the established capillary pressure equilibrium in the medium. In addition, less than fully hydrated water contents in the polymer electrolyte and catalyst layers are considered, and are integrated with the relevant liquid and vapor transfers in the gas diffusion layer. The developed performance equations take into account the influences of all pertinent material properties on cell performance using first principles. The mathematical approach is logical and concise in terms of revealing the underlying physical significance in comparison with many other empirical data fitting models. 相似文献
6.
Yulin Wang Shixue Wang Guozhuo Wang Like Yue 《International Journal of Hydrogen Energy》2018,43(4):2359-2368
The cathode flow-field design of a polymer electrolyte membrane (PEM) fuel cell is crucial to its performance, because it determines the distribution of reactants and the removal of liquid water from the fuel cell. In this study, the cathode flow-field of a parallel flow-field PEM fuel cell was optimized using a sub-channel. The main-channel was fed with moist air, whereas the sub-channel was fed with dry air. The influences of the sub-channel flow rate (SFR, the amount of air from the sub-channel inlet as a percentage of the total cathode flow rate) and the inlet positions (SIP, where the sub-channel inlets were placed along the cathode channel) on fuel cell performance were numerically evaluated using a three-dimensional, two-phase fuel cell model. The results indicated that the SFR and SIP had significant impacts on the distribution of the feed air, removal of liquid water, and fuel cell performance. It was found that when the SIP was located at about 30% along the length of the channel from main-channel inlet and the SFR was about 70%, the PEM fuel cell exhibited much better performance than seen with a conventional design. 相似文献
7.
Kookil Han Bo Ki HongSae Hoon Kim Byung Ki AhnTae Won Lim 《International Journal of Hydrogen Energy》2010
The effects of gas diffusion layer’s (GDL’s) anisotropic bending stiffness on the electrochemical performances of polymer electrolyte membrane fuel cells have been investigated for carbon fiber-felt and -paper GDLs. The bending stiffness values of all GDLs in the machine direction are higher than those in the cross-machine direction. We have prepared GDL sheet samples such that the machine direction of GDL roll is aligned with the major flow field direction of a metallic bipolar plate at angles of 0° (parallel: ‘0° GDL’) and 90° (perpendicular: ‘90° GDL’). The I–V performances of all the 5-cell stacks with 90° GDLs are higher than those with 0° GDLs. All the 5-cell stacks with 90° GDLs show lower values of high-frequency resistance (HFR) than those with 0° GDLs. However, the gas pressure differences at both anode and cathode of 5-cell stacks with 90° GDLs appear to be similar to or slightly lower than those with 0° GDLs, making the lower HFR as a dominant factor for the improved I–V performances. This may result from the reduced intrusion of 90° GDLs into gas channels than 0° GDLs as observed by less thickness reduction under compression of 90° GDLs. A 45° GDL (skew alignment) also shows better performances than the 0° GDL. 相似文献
8.
Nigel A. David Peter M. Wild Jingwei Hu Nedjib Djilali 《Journal of power sources》2009,192(2):376-380
A new application of in-fibre Bragg grating (FBG) sensors for the distributed measurement of temperature inside a polymer electrolyte membrane fuel cell is demonstrated. Four FBGs were installed on the lands between the flow channels in the cathode collector plate of a single test cell, evenly spaced from inlet to outlet. In situ calibration of the FBG sensors against a co-located micro-thermocouple shows a linear, non-hysteretic response, with sensitivities in good agreement with the expected value. A relative error of less than 0.2 ° C over the operating range of the test cell (∼20-80 °C) was achieved, offering sufficient resolution to measure small gradients between sensors. While operating the fuel cell at higher current densities under co-flow conditions, gradients of more than 1 ° C were measured between the inlet and outlet sensors. Due to their small thermal mass, the sensors also exhibit good temporal response to dynamic loading when compared with the thermocouple. Design and instrumentation of the graphite collector plate features minimal intrusion by the sensors and easy adaptation of the techniques to bipolar plates for stack implementation. 相似文献
9.
10.
A free vibration analysis of a polymer electrolyte membrane fuel cell (PEMFC) is performed by modelling the PEMFC as a 20 cm × 20 cm composite plate structure. The membrane, gas diffusion electrodes, and bi-polar plates are modelled as composite material plies. Energy equations are derived based on Mindlin's plate theory, and natural frequencies and mode shapes of the PEMFC are calculated using finite element modelling. A parametric study is conducted to investigate how the natural frequency varies as a function of thickness, Young's modulus, and density for each component layer. It is observed that increasing the thickness of the bi-polar plates has the most significant effect on the lowest natural frequency, with a 25% increase in thickness resulting in a 17% increase in the natural frequency. The mode shapes of the PEMFC provide insight into the maximum displacement exhibited as well as the stresses experienced by the single cell under vibration conditions that should be considered for transportation and stationary applications. This work provides insight into how the natural frequencies of the PEMFC should be tuned to avoid high amplitude oscillations by modifying the material and geometric properties of individual components. 相似文献
11.
The catalyst layers are the most important part of the polymer electrolyte membrane (PEM) fuel cells, and the cell performance is highly related to its structure. The gas diffusion layers (GDLs) are also the essential components of the PEM fuel cell since the reactants should pass through these layers. Model prediction shows that electrical current in catalyst layer is non-uniform, influenced by the channel-land geometry. In addition, the compression effect of GDLs and water generation due to the electrochemical reaction may cause non-uniformity in porosity and, therefore, increases the non-uniformity in reactant concentration in GDL/catalyst layer interface. Simulation results suggest that non-uniform catalyst loading distribution in the catalyst layer will improve the performance of the whole catalyst layer by diminishing the variation in current density. 相似文献
12.
Degradation behaviors of polymer electrolyte membrane fuel cell (PEMFC) in high current density region were investigated under Freeze/Thaw cycles. Different dehumidification scenarios namely hot purge, cold purge and no purge were adopted for comparison. Micrographs from scanning electron microscopy proved little change in catalyst-coated membrane (CCM) integrity, no delamination or segregation occurred after many freeze/thaw cycles. Cyclic Voltammetry (CV) measurement revealed reduction in electrochemical active surface area of CCM. The observed performance decay in the high current density region was mainly attributed to the increased interface contact resistance and degraded electric and gas coupling characteristics at interfaces between CCM and GDL in this paper. Meanwhile, the performance degradation under low current densities (for example 400 mA cm−2 or even lower) was mainly ascribed to the degraded characteristics of catalyst layers referring to CCM as cyclic voltammetry indicated. Proper dehumidification through gas purging is effective to maintain stable preference under subzero temperature. 相似文献
13.
Yong-Hun Cho Jinho Kim Tae-Yeol Jeon Namgee Jung Ju Wan Lim Won-Sub Yoon Yung-Eun Sung 《Journal of power sources》2010,195(18):5952-9515
A catalyst-coated membrane (CCM) as used in the membrane electrode assembly (MEA) of a polymer electrolyte membrane fuel cell is treated by dilute sulfuric acid solution (0.5 M) at boiling temperature for 1 h. This treatment improves the single-cell performance of the CCM without further addition of Pt catalyst. The changed microstructure and electrochemical properties of the catalyst layer are investigated by field emission scanning electron microscopy with energy dispersive X-ray, mercury intrusion porosimetry, waterdrop contact angle measurement, Fourier transform-infrared spectrometry in attenuated total reflection mode, electrochemical impedance spectroscopy, and cyclic voltammetry. The results indicate that this pretreatment enhances MEA performance by changing the microstructure of the catalyst layer and thus changing the degree of hydration, and by modifying the Pt surface, thus enhancing the oxygen reduction reaction. 相似文献
14.
Jongrok KimJunho Je Massoud Kaviany Sang Young SonMooHwan Kim 《Journal of power sources》2011,196(20):8398-8401
The fuel crossover and internal current in a polymer electrolyte membrane fuel cell undergo a chemical reaction in the cell without power generation. These are the main phenomena for reduced cell voltage at low current density. This fuel crossover also degrades the fuel cell performance, efficiency, and durability. Thus, observation of these phenomena is important for understanding and developing a polymer electrolyte membrane fuel cell. Using X-ray radiography, the water distribution and membrane swelling, which indicate fuel crossover and internal current, in an operating polymer electrolyte membrane fuel cell under open-circuit conditions were examined. The X-ray images effectively demonstrated the transient changes of each phenomenon, which are related to the properties of each component and the operating conditions. 相似文献
15.
Arasy Fahruddin Djatmiko Ichsani Fadlilatul Taufany Budi U.K. Widodo Wawan A. Widodo 《International Journal of Hydrogen Energy》2021,46(8):6028-6036
Flow field design on the cathode side, inspired by leaf shapes, leads to a high performance, as it achieves a good distribution of reactants. Furthermore, the addition of baffles to the cathode channel also increases the supply of reactants in the cathode catalyst. However, research on the addition of baffles to the cathode channel has still been limited to straight channels and conventional flow fields. Therefore, in this work, a numerical study was conducted to investigate the effect of baffles on the leaf flow field on the performance of a polymer electrolyte membrane fuel cell. The generated 3D model is composed of nine layers with a 25-cm2 active area. The beam and chevron shapes of the baffles, which were inserted into the mother channel, were compared. The simulation results revealed that the addition of beam-shaped baffles that are close to each other can increase the current and power densities by up to 18% due to the more uniform distribution of the oxygen mass fraction. 相似文献
16.
Jincheol Kim Dong-Min Kim Sung-Yug Kim Suk Woo Nam Taegyu Kim 《International Journal of Hydrogen Energy》2014
In the present study, a short circuit controller for use in the humidification of polymer electrolyte membrane fuel cells was developed for unmanned aerial vehicles (UAVs). Fuel cells (FCs) require an external humidifier to avoid drying up. Particularly in UAV applications, humidity control is more important because the boiling point of water decreases with increase in flight altitude. In this study, overcurrent was generated by short-circuiting an FC to humidify the electrolyte membrane and improve the electric power output. An FC controller incorporating a short circuit unit was developed, and a battery was hybridized with the FC to compensate the power when the latter was short-circuited. The performance of the FC was evaluated for the interval (period) and duration of short circuit. Using this method, the power output was improved by 16% when short circuit control was operated at the optimal condition. 相似文献
17.
Daniel Ritzberger Johannes Höflinger Zhang Peng Du Christoph Hametner Stefan Jakubek 《International Journal of Hydrogen Energy》2021,46(21):11878-11893
In order to mitigate the degradation and prolong the lifetime of polymer electrolyte membrane fuel cells, advanced, model-based control strategies are becoming indispensable. Thereby, the availability of accurate yet computationally efficient fuel cell models is of crucial importance. Associated with this is the need to efficiently parameterize a given model to a concise and cost-effective experimental data set. A challenging task due to the large number of unknown parameters and the resulting complex optimization problem. In this work, a parameterization scheme based on the simultaneous estimation of multiple structured state space models, obtained by analytic linearization of a candidate fuel cell stack model, is proposed. These local linear models have the advantage of high computational efficiency, regaining the desired flexibility required for the typically iterative task of model parameterization. Due to the analytic derivation of the local linear models, the relation to the original parameters of the non-linear model is retained. Furthermore, the local linear models enable a straight-forward parameter significance and identifiability analysis with respect to experimental data. The proposed method is demonstrated using experimental data from a 30 kW commercial polymer electrolyte membrane fuel cell stack. 相似文献
18.
Hongliang Jiang Liangfei Xu Chuan Fang Xingwang Zhao Zunyan Hu Jianqiu Li Minggao Ouyang 《International Journal of Hydrogen Energy》2017,42(29):18551-18559
Durability and start-up ability in sub-zero environment are two technical bottlenecks of vehicular polymer electrolyte membrane (PEM) fuel cell systems. With exhaust gas recirculation on the anode and cathode side, the cell voltage at low current density can be reduced, and the membrane can be humidified without external humidifier. They may be helpful to prolong the working lifetime and to promote the start-up ability. This paper presents an experimental study on a PEM fuel cell system with anodic and cathodic recirculation. The system is built up based on a 10 kW fuel cell stack, which consists of 50 cells and has an active area of 261 cm2. A cathodic recirculation pump and a hydrogen recirculation pump are utilized on the cathode and anode side, respectively. Key parameters, e.g., stack current, stack voltage, cell voltage, air flow, relative humidity on the cathode side, oxygen concentration at the inlet and outlet of the cathode side, are measured. Results show that: 1) with a cathodic recirculation the system gets good self-humidification effect, which is similar to that with an external humidifier; 2) with a cathodic recirculation and a reduction of fresh air flux, the cell voltage can be obviously reduced; 3) with an anodic recirculation the cell voltage can also be reduced due to a reduction in the hydrogen partial pressure, the relative humidity on the cathode side is a little smaller than the case with only cathode recirculation. It indicates that, for our stack the cathodic recirculation is effective to clamp cell voltage at low current density, and a self-humidification system is possible with cathodic recirculation. Further study will focus on the dynamic model and control of the dual recirculation fuel cell system. 相似文献
19.
《International Journal of Hydrogen Energy》2020,45(51):27622-27631
In this study, a novel way to improve performance of the air-cooled open cathode polymer electrolyte membrane fuel cell is introduced. We suggest using a metal foam in the cathode side of the planar unit fuel cell for the solution to conventional problems of the open cathode fuel cell such as excessive water evaporation from the membrane and poor transportation of air. We conduct experiment and the maximum power density of the fuel cell with metal foam increases by 25.1% compared with the conventional fuel cell without metal foam. The open cathode fuel cell with metal foam has smaller ohmic losses and concentration losses. In addition, we prove that the open cathode fuel cell with metal foam prevents excessive water evaporation and membrane drying out phenomena with numerical approach. Finally, we apply the metal foam to the air-cooled open cathode fuel cell stack as well as the planar unit cell. 相似文献
20.
Yukwon Jeon Hyung-kwon Hwang Jeongho Park Hojung Hwang Yong-Gun Shul 《International Journal of Hydrogen Energy》2014
We report on polymer electrolyte membrane fuel cells (PEMFCs) that function at high temperature and low humidity conditions based on short-side-chain perfluorosulfonic acid ionomer (SSC-PFSA). The PEMFCs fabricated with both SSC-PFSA membrane and ionomer exhibit higher performances than those with long-side-chain (LSC) PFSA at temperatures higher than 100 °C. The SSC-PFSA cell delivers 2.43 times higher current density (0.524 A cm−1) at a potential of 0.6 V than LSC-PFSA cell at 140 °C and 20% relative humidity (RH). Such a higher performance at the elevated temperature is confirmed from the better membrane properties that are effective for an operation of high temperature fuel cell. From the characterization technique of TGA, XRD, FT-IR, water uptake and tensile test, we found that the SSC-PFSA membrane shows thermal stability by higher crystallinity, and chemical/mechanical stability than the LSC-PFSA membrane at high temperature. These fine properties are found to be the factor for applying Aquivion™ E87-05S membrane rather than Nafion® 212 membrane for a high temperature fuel cell. 相似文献