Replacing the Battery in Portable Electronics

Dyer, C. K.

doi:10.1038/scientificamerican0799-88

Cited by 66 publications

(58 citation statements)

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“…[3] As shown in Figure 1, the basic constituents of a PEMFC are an anode, an external circuit, a proton-exchange membrane (PEM), and a cathode. The fuel, typically H 2 (g), is oxidized at the anode over an electrocatalyst, for example, Pt or Pt-Ru nanoparticles, to produce protons and electrons.…”

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confidence: 99%

The Use of¹H NMR Microscopy to Study Proton‐Exchange Membrane Fuel Cells

2006

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To understand proton-exchange membrane fuel cells (PEMFCs) better, researchers have used several techniques to visualize their internal operation. This Concept outlines the advantages of using 1H NMR microscopy, that is, magnetic resonance imaging, to monitor the distribution of water in a working PEMFC. We describe what a PEMFC is, how it operates, and why monitoring water distribution in a fuel cell is important. We will focus on our experience in constructing PEMFCs, and demonstrate how 1H NMR microscopy is used to observe the water distribution throughout an operating hydrogen PEMFC. Research in this area is briefly reviewed, followed by some comments regarding challenges and anticipated future developments.

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confidence: 99%

The Use of¹H NMR Microscopy to Study Proton‐Exchange Membrane Fuel Cells

2006

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“…Hence if Nafion 117 was to be used for DEFCs, the ethanol concentration in the fuel has to be kept sufficiently low to reduce fuel crossover. This is similar to the situation in DMFCs, where the concentration of methanol in the fuel is limited to 0.5-1.0 M for the same reason [35]. As the PVA/poly(AMPS-co-HEMA)/TEOS membranes have significantly less swelling in ethanol solutions, it is expected that the membranes would exhibit lower ethanol permeability at higher fuel concentrations (see discussion later), allowing a higher fuel concentration to be used.…”

Section: Solvent Uptake and Fuel Permeabilitymentioning

confidence: 76%

Membrane Design for Direct Ethanol Fuel Cells: A Hybrid Proton‐Conducting Interpenetrating Polymer Network

Hong

Lee

2008

Fuel Cells

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A series of hybrid proton‐conducting membranes with an interpenetrating polymer network (IPN) structure was designed with the direct ethanol fuel cell (DEFC) application in mind. In these membranes, glutaraldehyde crosslinked poly(vinyl alcohol) (PVA) were interpenetrated with the copolymer of 2‐acrylamido‐2‐methyl‐propanesulphonic acid (AMPS) and 2‐hydroxyethyl methacrylate (HEMA) crosslinked by poly(ethylene glycol) dimethacrylate (PEGDMA). Silica from the in situ sol–gel hydrolysis of tetraethyl orthosilicate (TEOS) was uniformly dispersed in the polymer matrix. The membranes fabricated as such had ion exchange capacities of 0.84–1.43 meq g–1 and proton conductivities of 0.02–0.11 S cm–1. The membranes exhibited significantly lower fuel permeabilities than that of Nafion. In a manner totally unlike Nafion, fuel permeabilities were lower at higher fuel concentrations, and were lower in ethanol than methanol solutions. These behaviours are all relatable to the unique swelling characteristics of PVA (no swelling in ethanol, partial swelling in methanol and extensive swelling in water) and to the fuel blocking and swelling suppression properties of silica particles. The membranes are promising for DEFC applications since a high concentration of fuel may be used to reduce fuel crossover and to improve the anode kinetics for a resultant increase in both the energy and power densities of the fuel cell.

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“…9.1, the theoretical specific energy of a DMFC operating with different methanol concentrations is compared to a state-of-the-art Li-ion battery. The change of the specific energy of the fuel with the methanol concentration of solution, represented by the dashed line, indicates that the specific energy of the methanol solution with a concentration above 2 M will be greater than that of Li-ion batteries (~350 Wh · dm À3 [7]), while the specific energy of pure methanol is as high as 4,900 Wh · dm À3 [8,9], that is, 14 times higher than that of the battery. However, the data in Fig.…”

Section: Introductionmentioning

confidence: 97%

Applications and Durability of Direct Methanol Fuel Cells

Franceschini

Corti

2013

Direct Alcohol Fuel Cells

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Many companies are making significant efforts in the development of prototypes of DAFC (mainly DMFC) for replace batteries (battery charge and auxiliary power units) in portable devices. Some of the most relevant prototypes are summarized; however, most of these devices are not ready to be commercialized due to the high cost and low power reached. Furthermore, for the massive application of the DAFC technologies is necessary solve some of the drawbacks (as miniaturization, products balance, cost reduction, etc.). The cost of the prototypes is analyzed as well as the degradation of the components that affects the durability of the devices.

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Replacing the Battery in Portable Electronics

Cited by 66 publications

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The Use of¹H NMR Microscopy to Study Proton‐Exchange Membrane Fuel Cells

The Use of¹H NMR Microscopy to Study Proton‐Exchange Membrane Fuel Cells

Membrane Design for Direct Ethanol Fuel Cells: A Hybrid Proton‐Conducting Interpenetrating Polymer Network

Applications and Durability of Direct Methanol Fuel Cells

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Replacing the Battery in Portable Electronics

Cited by 66 publications

References 0 publications

The Use of1H NMR Microscopy to Study Proton‐Exchange Membrane Fuel Cells

The Use of1H NMR Microscopy to Study Proton‐Exchange Membrane Fuel Cells

Membrane Design for Direct Ethanol Fuel Cells: A Hybrid Proton‐Conducting Interpenetrating Polymer Network

Applications and Durability of Direct Methanol Fuel Cells

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The Use of¹H NMR Microscopy to Study Proton‐Exchange Membrane Fuel Cells

The Use of¹H NMR Microscopy to Study Proton‐Exchange Membrane Fuel Cells