Cold Start of a Polymer-Electrolyte Fuel Cell II. Model Verification Using Parametric Studies

Balliet, Ryan; Newman, John

doi:10.1149/1.3592484

Cited by 19 publications

(27 citation statements)

References 11 publications

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“…• C. 9 The work by Thompson et al has demonstrated that PEM thickness and the anode CL do not significantly contribute to differences in the water storage capacity. 32 To confirm the absence of PEM type/thickness, an additional baseline Sprayed CL was applied to Nafion NR-212 to directly compare to Decal CLs.…”

Section: Resultsmentioning

confidence: 99%

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The Effect of Material Properties on the Subzero Water Storage Capacity of Cathode Catalyst Layers for Proton Exchange Membrane Fuel Cells

Pistono¹,

Rice²

2017

J. Electrochem. Soc.

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Proton Exchange Membrane Fuel Cell cold start performance and durability from subzero conditions are dependent upon the cathode catalyst layer (CL) structure and interfacial binding to the membrane. The CL constituents and fabrication methodology impact the amount and location of freezing point depressed water available for proton conduction at subzero temperatures, water storage capacity and mechanical stability. Two common types of CL fabrication methods were studied to compare and contrast the nominal operational performance (80 • C polarization curves) and water storage capacity at −10 • C, −20 • C, and −30 • C; Decal Transfer versus Direct Spray. The cathode platinum on carbon CL constituents were also varied; ionomer-to-carbon support loadings (20wt% and 30wt%) and ionomer equivalent weight (830EW, 1000EW, and 1100EW). The different cathode CLs were assessed for resistance to proton conduction (R H + ) and electrochemical surface area (ECSA). The Sprayed cathode CL had the least R H + and highest ECSA, while decreasing the EW negatively impacted the electronic continuity of the CL. The baseline configuration (1100EW 30wt%) nominal operational iR-free voltages at 500 mA cm −2 were 50 mV higher for the Spray method. Subzero isothermal water fill tests (WFTs) at −10 mA cm −2 measured water storage capacity at freeze-out; Decal transfer was 2-2.5x higher than Spray CLs.

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Section: Resultsmentioning

confidence: 99%

“…9,10 Initially an OCV was established greater than 0.97 V and then a small constant load of 10 mA cm −2 was applied. The cell voltage and cell resistance (via current interrupt) were monitored.…”

Section: Water Fill Tests-the Isothermal Wfts Were Performed At Subzmentioning

confidence: 99%

The Effect of Material Properties on the Subzero Water Storage Capacity of Cathode Catalyst Layers for Proton Exchange Membrane Fuel Cells

Pistono¹,

Rice²

2017

J. Electrochem. Soc.

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“…According to the literature, the dominant subzero PEMFC studies investigating the influence of material and operational parameters have been restricted to subscale single-cell freeze-thaw testing [3][4][5][6][7][8][9][10][11][12][13][14], isothermal water fill tests , and non-isothermal water fill tests [3,21,33,[38][39][40][41][42][43][44][45][46][47]. United Technology Corporation (UTC) Power and its corporate research facility co-developed two quasi-adiabatic single PEMFC fixtures in the mid-2000s with geometric active areas of 25 cm 2 and 320 cm 2 [48][49][50]. The results demonstrated that it was possible under a galvanic load cold-start to replicate the center cells in a stack's voltage and thermal profile in the quasi-adiabatic fixture.…”

Section: Introductionmentioning

confidence: 99%

“…The results demonstrated that it was possible under a galvanic load cold-start to replicate the center cells in a stack's voltage and thermal profile in the quasi-adiabatic fixture. Balliet and Newman validated their two-dimensional liquid water transport cold-start model to the UTC-Power's quasi-adiabatic PEMFC fixture performance profiles [49]. However, the inadequate structural integrity of the quasi-adiabatic PEMFC fixture limited its reusability.…”

Section: Introductionmentioning

confidence: 99%

Automotive Subzero Cold-Start Quasi-Adiabatic Proton Exchange Membrane Fuel Cell Fixture: Design and Validation

Pistono

Rice

2020

Molecules

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Subzero automotive cold-starts of proton exchange membrane fuel cell (PEMFC) stacks require accelerated thermal rises to achieve nominal operating conditions and close-to-instantaneous usable output power. Advances in the material, structure and operational dependence on the balance between the maximum power output and the electrochemical conversion of hydrogen and oxygen into water requires validation with subzero cold-starts. Herein are presented the design and validation of a quasi-adiabatic PEMFC to enable single-cell evaluation, which would provide a more cost-effective option than stack-level testing. At –20 °C, the operational dependence of the preconditioned water content (3.2 verse 6.2) for a galvanic cold-start (<600 mA cm−2) was counter to that of a laboratory-scale isothermal water fill test (10 mA cm−2). The higher water content resulted in a faster startup to appreciable power output within 0.39 min versus 0.65 min. The water storage capacity, as determined from the isothermal water fill test, was greater, for the lower initial water content of 3.2, than 6.2, 17.4 ± 0.3 mg versus 12.8 ± 0.4 mg, respectively. Potentiostatic cold-starts produced usable power in 0.09 min. The versatility and reproducibility of the single cell quasi-adiabatic fixture avail it to future universal cold-start stack relevant analyzes involving operational parameters and advanced materials, including: applied load, preconditioning, interchanging flow field structures, diffusion media, and catalyst coated membranes.

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“…Isothermal studies have focused on understanding mechanisms of water storage in the membrane/cathode catalyst layer (8). Recent non-isothermal modeling and experiments of cold start suggest that adverse negative voltages occur at cold starts below -20°C due to low ionomer ionic conductivity (9).…”

Section: Introductionmentioning

confidence: 99%

Subzero Degradation Analysis of Membrane Electrode Assemblies Modified with Additives

et al. 2013

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Baseline results for a direct sprayed membrane electrode assembly (MEA) are presented over the course of subzero isothermal water fill tests. The MEA exhibited very little degradation as measured by current step sweeps using 4 different oxidizing gasses. MEAs with additives have been prepared to address the issue of water storage in the cathode catalyst layer and ionic conductivity of the catalyst layer at subzero conditions.

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Cold Start of a Polymer-Electrolyte Fuel Cell II. Model Verification Using Parametric Studies

Cited by 19 publications

References 11 publications

The Effect of Material Properties on the Subzero Water Storage Capacity of Cathode Catalyst Layers for Proton Exchange Membrane Fuel Cells

The Effect of Material Properties on the Subzero Water Storage Capacity of Cathode Catalyst Layers for Proton Exchange Membrane Fuel Cells

Automotive Subzero Cold-Start Quasi-Adiabatic Proton Exchange Membrane Fuel Cell Fixture: Design and Validation

Subzero Degradation Analysis of Membrane Electrode Assemblies Modified with Additives

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