Load changing characteristics of the hydrogen‐air and hydrogen‐oxygen proton exchange membrane fuel cells

Huang, Zhenkai; Xing, Lu; Tu, Zhengkai

doi:10.1002/er.7306

Cited by 14 publications

(9 citation statements)

References 41 publications

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“…Dehydration of the MEA often occurs when the operating temperature exceeds a certain threshold, resulting in increased resistance. 20 Based on the previous correction of the membrane resistance, the corrected simulation results demonstrated favorable agreement with the experimental data during the transition of the model to the ohmic region, exhibiting a relative error of less than 5% spanning the entire polarization curve. Subsequently, the polarization curve of the cell was predicted and validated under specific conditions, including an operating temperature of 95 °C and anode/cathode inlet pressures of 280/260 kPa.…”

Section: Concentration Overpotentialsupporting

confidence: 56%

Theoretical and Experimental Study of a Fuel Cell Stack Based on Perfluoro-sulfonic Acid Membranes Facing High Temperature Application Environments

Lu,

Wu,

Yang

et al. 2024

Energy Fuels

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Elevating the operating temperature of fuel cell stacks based on perfluorosulfonic acid (PFSA) membranes is crucial for simplifying their cooling system and enhancing power density. In this study, we used a semiempirical model to correct the conductivity of the PFSA membrane at high temperatures and analyzed the impact of elevating the operating temperature and inlet pressure on the output performance, voltage consistency, internal water content, and dynamic response of a 10 kW rated power fuel cell stack. The results show that increasing the operating temperature leads to a significant decrease in the output performance of the stack, resulting in poor voltage consistency, large voltage fluctuations, and overshooting during the dynamic response. To mitigate the impact of higher temperatures on the saturated vapor pressure, increasing the inlet pressure of the stack can effectively improve the output and dynamic performance. Similarly, the net water drag coefficient (α NWD ) can be used to characterize and monitor the water transport process within the fuel cell. Its value is positively correlated to the operating temperature and inlet pressure. Increasing humidity on the cathode side promotes water back-diffusion, thereby improving the high-temperature operation of the stack.

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Section: Concentration Overpotentialsupporting

confidence: 56%

Theoretical and Experimental Study of a Fuel Cell Stack Based on Perfluoro-sulfonic Acid Membranes Facing High Temperature Application Environments

Lu,

Wu,

Yang

et al. 2024

Energy Fuels

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“…According to the mass conservation, the water mass fraction in the anode and the nitrogen mass fraction in the cathode could be calculated as shown in Equations (12) and (13):…”

Section: Governing Equationsmentioning

confidence: 99%

“…Dynamic load changing significantly affects its operational stability. 13 Similarly, there are also dynamic performance differences among PEMFCs with varied flow fields. The dynamic characteristics of the straight channel, single-serpentine channel, the three-serpentine channel had been comparatively investigated by Yan et al 14 In the low current density area, undershoot of the response voltage was small, and the poorest dynamic performance was found in the straight channel.…”

mentioning

confidence: 99%

Performance improvement in a proton exchange membrane fuel cell with an innovative flow field design

Huang

Xing

2021

Intl J of Energy Research

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The flow field of the proton exchange membrane fuel cell (PEMFC) controls mass and water transfer; it significantly impacts the fuel cell's performance. It is critical to innovate the flow field design for optimizing the performance. This paper proposes a new-designed flow field (NDFF) patterned with the built-in blockage and trap-shape rib association. The novel design was analyzed numerically and experimentally. A three-dimensional isothermal numerical model was first established based on COMSOL software. This model demonstrated that the NDFF transformed the traditional diffusion mass transfer into the optimized diffusion and convection mass transfer combination.Compared with the conventional straight flow field, the effective mass transfer coefficient was considerably improved. Moreover, the new-designed structures enforced cyclical variation of local velocity and pressure, forming forced-convection, which was beneficial for water management. At 0.45AÁcm À2 , the steady-state voltage and the initial dynamic response voltage were increased by 0.08 V and 0.16 V; power density was increased by 20.1%. The experimental results were collected to validate the enhanced performance of PEMFC with the NDFF. Energy efficiency ratio (EER) was proposed as an evaluation criterion; EER results suggested NDFF can improve the net output power. Highlights• A new flow field patterned with built-in blockage and trap shape rib association• Energy efficiency ratio, effective mass transfer coefficient used for evaluation • Steady-state and dynamic performances are greatly improved at an increased Energy efficiency ratioenergy efficiency ratio, flow field, oxygen and water distribution, proton exchange membrane fuel cell | INTRODUCTIONClimate change caused by environmental pollution and global warming is getting great attention; PEMFCs demonstrated outstanding potential for their advantage of zero-pollution. 1-3 Significant progress has been achieved in developing PEMFC's technologies; however, the cost is still one main obstacle that restricts the large-scale commercialization. 4 The cost can be reduced by improving PEMFC's performance. 5 Flow field significantly affects a fuel cell's performance, whose difference among PEMFCs with

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“…In these cases, an enhanced pressure difference between anode and cathode is beneficial for the output performance of PEMFCs under the premise of ensuring the safety of PEMs because it can alleviate water flooding in the cathode [17][18][19][20][21]. Moreover, reasonably high temperature can promote the mass transfer of reactants and proton conductivity [2,22]. Therefore, it is essential to investigate the transport processes of proton and water under different pressure differences and temperatures.…”

Section: Introductionmentioning

confidence: 99%

Molecular Study of Nonequilibrium Transport Mechanism for Proton and Water in Porous Proton Exchange Membranes

Wang

Liu

et al. 2023

International Journal of Energy Research

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The transport process of proton and water through a porous proton exchange membrane (PEM) under pressure difference is significant to fuel cell performance. Nonequilibrium molecular dynamics simulations were conducted to investigate the diffusion mechanisms of hydronium ions and water molecules under pressure differences. Here, different driving forces (0.15 kcal/(mol·Å)–0.45 kcal/(mol·Å)) were applied to hydronium ions and water molecules as they transported through Nafion 117 membrane at temperatures between 300 K and 350 K. Results indicated that the transport diffusion coefficient of water molecules was larger than that of hydronium ions under different pressure drops due to the lower molecular weight and diffusion activation energy of water molecules (20.25 kJ/mol). Hydronium ions formed stronger hydrogen bonds with sulfonic acid groups than water molecules, which resulted in a higher diffusion activation energy for hydronium ions (21.15 kJ/mol). The proton conductivity rose with the increase in pressure difference. Moreover, the transport diffusion coefficient of water molecules and hydronium ions were positively correlated with temperature. This is because the kinetic energy of molecules increased and the pore size of the Nafion membrane enlarged at high temperatures. In addition, the dynamics of the hydrogen bond between hydronium ions and sulfonic acid groups/water molecules were accelerated at elevated temperatures, which further promoted proton transfer.

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Load changing characteristics of the hydrogen‐air and hydrogen‐oxygen proton exchange membrane fuel cells

Cited by 14 publications

References 41 publications

Theoretical and Experimental Study of a Fuel Cell Stack Based on Perfluoro-sulfonic Acid Membranes Facing High Temperature Application Environments

Theoretical and Experimental Study of a Fuel Cell Stack Based on Perfluoro-sulfonic Acid Membranes Facing High Temperature Application Environments

Performance improvement in a proton exchange membrane fuel cell with an innovative flow field design

Molecular Study of Nonequilibrium Transport Mechanism for Proton and Water in Porous Proton Exchange Membranes

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