Carbon nanotube sheet as a microporous layer for proton exchange membrane fuel cells

Intl J of Energy Research

et al. 2022

Self Cite

Summary An ultrathin layer composed of carbon nanotubes (CNTs) was deposited on the cathodic catalyst layer to boost performance of polymer electrolyte membrane fuel cell (PEMFC) under low to mid relative humidity (RH) conditions. The CNT‐deposited layer (CDL) was formed without modifying the PEMFC components. To investigate the behavior of water and reactants at the inner interface of the membrane electrode assembly (MEA), we characterized the morphology of the CDL (contact angle, pore size distribution, specific surface area, field emission scanning electron microscopy, and energy dispersive spectroscopy images). The CDL in PEMFCs was used as a contributor to enhance the membrane hydration. Thereby performances have been significantly enhanced. Additionally, the three‐dimensional nanostructure of the CDL expanded the active area by uniform dispersion of the reactants. The polarization curves of the conventional MEA and MEA with CDL were evaluated under diverse RH (100%, 70%, 50%, and 30% RH). In the low to mid RH conditions, the maximum power densities were increased by 29.7% (70% RH), 26.6% (50% RH), and 25.5% (30% RH) compared with the conventional MEA. Especially, the maximum power density of the MEA with CDL (0.547 W/cm2 at 70% RH) was higher than that of the conventional MEA (0.482 W/cm2 at 100% RH). Thus, MEA with CDL demonstrated excellent performance enhancement under low to mid RH conditions.

Section: Resultsmentioning

confidence: 93%

Section: Resultsmentioning

confidence: 99%

Section: Characterization Of CDLmentioning

confidence: 96%

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Carbon nanotube‐deposited layer on cathodic catalyst layer in polymer electrolyte membrane fuel cell for enhanced performance in low humidity condition

Jeong

Kwon

Intl J of Energy Research

et al. 2022

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“…The measurement of 0.96 V using a 1.46 umthick Ag current collecting layer cell was relatively lower than other OCVs. However, a number of prior studies showed around 1.0 V of OCVs [2,3,[5][6][7][16][17][18][19][20]. This is because of the inherent hydrogen permeability of Nafion ® , PTFE gaskets, etc.…”

Section: Resultsmentioning

confidence: 98%

Effects of Ag Current Collecting Layer Fabricated by Sputter for 3D-Printed Polymer Bipolar Plate of Ultra-Light Polymer Electrolyte Membrane Fuel Cells

Jang

Cho

2022

Sustainability

In this study, 3D-printed polymer bipolar plates were fabricated and applied to the polymer electrolyte membrane fuel cells (PEMFCs). In order to overcome the poor electronic conductivity of polymer bipolar plates, silver current collecting layers were deposited using a sputter process. Influences of the thickness of the current collecting layer were carefully investigated to optimize the thickness. Using a sputter process, current collecting layers were successfully deposited without clear evidence of defects. Additionally, the increment in the total weight of bipolar plates was minimized. The average thickness of the silver current collecting layer was varied from 216 nm to 1.46 um. The results showed the fuel cell with 1.46 um thick Ag current collecting layer coated 3D printed bipolar plates achieved 0.96 V of the open circuit voltage and 308.35 mW/cm2 of performance at 25 °C.

“…The same composition of ink has been used elsewhere. 33,34 The mixed elements were sonicated for 60 min. Only one ink was prepared for each cell; for example, the ink for Cell 2 is diluted with each cycle (some of the solid components are deposited on the membrane or GDL) and recycled for subsequent cycles.…”

Section: Methodsmentioning

confidence: 99%

Non‐destructive platinum catalyst‐replenishment method for deteriorated polymer electrolyte membrane fuel cells

Yoo

Energy Science & Engineering

et al. 2021

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A novel method for replenishing platinum catalysts on an electrolyte membrane of polymer electrolyte membrane fuel cell (PEMFC) is studied. The method injects electrocatalyst-supplementing ink into a pre-assembled fuel cell in a simple and non-destructive manner. For replenishing, straightforward catalystreplenishment equipment and corresponding protocol are proposed. The protocol consists of injection, penetration, and purge processes. As a feasibility study, the method is performed on fuel cells with pristine membranes. Target fuel cells for this study include a membrane-assembled cell without catalyst layers (CLs) (Cell 1) and a cell assembled with a membrane-coated cathodic CL (Cell 2). An open-circuit voltage of 0.804 V in Cell 1 and a current of 77 mA in Cell 2 are measured, as supported through electrochemical impedance spectroscopy. Results of energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy also support the presence of platinum catalysts.