Organic Proton‐Conducting Molecules as Solid‐State Separator Materials for Fuel Cell Applications

Jiménez‐García, Lucía; Kaltbeitzel, Anke; Enkelmann, Volker; Gutmann, Jochen S.; Klapper, Markus; Müllen, Kläus

doi:10.1002/adfm.201002357

Cited by 43 publications

(44 citation statements)

References 57 publications

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“…5,44 Accordingly, the ion transport into the storage sites of the electrode surface is a key to achieving good capacitive and rate performances at high temperatures.…”

Section: Resultsmentioning

confidence: 99%

Extremely Durable, Flexible Supercapacitors with Greatly Improved Performance at High Temperatures

et al. 2015

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The reliability and durability of energy storage devices are as important as their essential characteristics (e.g., energy and power density) for stable power output and long lifespan and thus much more crucial under harsh conditions. However, energy storage under extreme conditions is still a big challenge because of unavoidable performance decays and the inevitable damage of components. Here, we report high-temperature operating, flexible supercapacitors (f-SCs) that can provide reliable power output and extreme durability under severe electrochemical, mechanical, and thermal conditions. The outstanding capacitive features (e.g., ∼40% enhancement of the rate capability and a maximum capacitances of 170 F g(-1) and 18.7 mF cm(-2) at 160 °C) are attributed to facilitated ion transport at elevated temperatures. Under high-temperature operation and/or a flexibility test in both static and dynamic modes at elevated temperatures >100 °C, the f-SCs showed extreme long-term stability of 100000 cycles (>93% of initial capacitance value) and mechanical durability after hundreds of bending cycles (at bend angles of 60-180°). Even at 120 °C, the versatile design of tandem serial and parallel f-SCs was demonstrated to provide both desirable energy and power requirements at high temperatures.

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“…5,44 Accordingly, the ion transport into the storage sites of the electrode surface is a key to achieving good capacitive and rate performances at high temperatures.…”

Section: Resultsmentioning

confidence: 99%

Extremely Durable, Flexible Supercapacitors with Greatly Improved Performance at High Temperatures

et al. 2015

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“…The cyclotrimerization reaction was performed with Co 2 (CO) 8 as the catalyst, which yielded symmetric (1) and asymmetric isomers (2). Because of the reaction mechanism, www.chemeurj.org which proceeds through metallacyclopentadiene intermediates, [23] two different isomers with chromophore substituents at the 1,3,5-and 1,2,4-positions are formed.…”

Section: Resultsmentioning

confidence: 99%

“…properties, HABs are used as proton conductors [8] and as precursors for molecular graphenes. [9] In the molecules studied herein, we use optically induced charge-transfer (CT) processes to investigate the energy-transfer pathways between the CT states by performing steady-state anisotropy fluorescence measurements.…”

Section: Introductionmentioning

confidence: 99%

Charge‐Transfer Interactions in Tris‐Donor–Tris‐Acceptor Hexaarylbenzene Redox Chromophores

Steeger¹,

Lambert²

2012

Chemistry A European J

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Symmetric- and asymmetric hexaarylbenzenes (HABs), each substituted with three electron-donor triarylamine redox centers and three electron-acceptor triarylborane redox centers, were synthesized by cobalt-catalyzed cyclotrimerization, thereby forming compounds with six- and four donor-acceptor interactions, respectively. The electrochemical- and photophysical properties of these systems were investigated by cyclovoltammetry (CV), as well as by absorption- and fluorescence spectroscopy, and compared to a HAB that only contained one neighboring donor-acceptor pair. CV measurements of the asymmetric HAB show three oxidation peaks and three reduction peaks, whose peak-separation is greatly influenced by the conducting salt, owing to ion-pairing and shielding effects. Consequently, the peak-separations cannot be interpreted in terms of the electronic couplings in the generated mixed-valence species. Transient-absorption spectra, fluorescence-solvatochromism, and absorption spectra show that charge-transfer states from the amine- to the boron centers are generated after optical excitation. The electronic donor-acceptor interactions are weak because the charge transfer has to occur predominantly through space. Moreover, the excitation energy of the localized excited charge-transfer states can be redistributed between the aryl substituents of these multidimensional chromophores within the fluorescence lifetime (about 60 ns). This result was confirmed by steady-state fluorescence-anisotropy measurements, which further indicated symmetry-breaking in the superficially symmetric HAB. Adding fluoride ions causes the boron centers to lose their accepting ability owing to complexation. Consequently, the charge-transfer character in the donor-acceptor chromophores vanishes, as observed in both the absorption- and fluorescence spectra. However, the ability of the boron center as a fluoride sensor is strongly influenced by the moisture content of the solvent, possibly owing to the formation of hydrogen-bonding interactions between water molecules and the fluoride anions.

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“…These kinds of polymers are the best heterocyclic polymer candidates, which have been used during the synthesis of coordination metallopolymers in a wide range of areas, including catalysis, luminescence, gas adsorption, magnetic materials, selective ion exchange resins, fuel cells and electrolyte membranes [23][24][25][26][27][28][29][30][31] .…”

Section: Introductionmentioning

confidence: 99%

In Situ Synthesis of Silver Nanoparticles in Novel L-Phenylalanine Based Poly(Amide-Benzimidazole-imide) Matrix Through Metal Complexation Method UsingN,N′-Dimethylformamide as a Reaction Medium and Reducing Agent

Abdolmaleki

Mallakpour

Borandeh

2015

Polymer-Plastics Technology and Engineering

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Silver nanoparticles were obtained in novel optically active poly(amide-benzimidazole-imide) (PABI) matrix through an in situ procedure. Chiral PABI was prepared by polycondensation of amino acid based diacid and benzimidazole containing diamine in the presence of molten tetrabutylammonium bromide. Synthesized PABI was characterized by several techniques, including Fourier transform infrared spectra, 1 H-NMR, elemental analysis, X-ray diffraction, thermogravimetric analysis and field emission scanning electron microscopy (FE-SEM). Then, PABI/Ag nanocomposite was fabricated based on metal complexation route for preparing silver nanoparticles in the PABI matrix and was characterized by various techniques. Microscopic images revealed good dispersion of Ag nanoparticles in the polymer matrix.

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Organic Proton‐Conducting Molecules as Solid‐State Separator Materials for Fuel Cell Applications

Cited by 43 publications

References 57 publications

Extremely Durable, Flexible Supercapacitors with Greatly Improved Performance at High Temperatures

Extremely Durable, Flexible Supercapacitors with Greatly Improved Performance at High Temperatures

Charge‐Transfer Interactions in Tris‐Donor–Tris‐Acceptor Hexaarylbenzene Redox Chromophores

In Situ Synthesis of Silver Nanoparticles in Novel L-Phenylalanine Based Poly(Amide-Benzimidazole-imide) Matrix Through Metal Complexation Method UsingN,N′-Dimethylformamide as a Reaction Medium and Reducing Agent

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