Metal-free aqueous redox capacitor via proton rocking-chair system in an organic-based couple

Tomai, Takaaki; Mitani, Satoshi; Komatsu, Daiki; Kawaguchi, Yuji; Honma, Itaru

doi:10.1038/srep03591

Cited by 93 publications

(126 citation statements)

References 24 publications

Supporting

Mentioning

123

Contrasting

Order By: Relevance

“…molecules and polymers) are expected as a positive electrode of rechargeable batteries [25,[32][33][34][35], and a high redox potential is desired to achieve a high voltage operation of the batteries. Accordingly, the pseudocapacitance of ZTC at a positive potential range by furan-type ether is of interest.…”

Section: Pseudocapacitance Of Ztc In 1 M Lipf 6 /Ec þDecmentioning

confidence: 99%

Pseudocapacitance of zeolite-templated carbon in organic electrolytes

Nueangnoraj

Nishihara

Ishii

et al. 2015

Energy Storage Materials

View full text Add to dashboard Cite

Section: Pseudocapacitance Of Ztc In 1 M Lipf 6 /Ec þDecmentioning

confidence: 99%

Pseudocapacitance of zeolite-templated carbon in organic electrolytes

Nueangnoraj

Nishihara

Ishii

et al. 2015

Energy Storage Materials

View full text Add to dashboard Cite

“…Both these phenomena are attributable to faradaic reactions on the surfaces of the electrodes, such that the rectangular shape of the CV curve is distorted by the voltage drop 30,31 and the capacitance in the CV curve is enhanced by an increase in the hydrogen storage capacity. 32,33 Only the MPC with an O/C atomic ratio of 0.131 deviated from these patterns, due to the large internal resistance of this specimen (Fig. 2b).…”

Section: Resultsmentioning

confidence: 99%

Design of a Rechargeable Fuel-Cell Battery with Enhanced Performance and Cyclability

Hibino

Kobayashi

Nagao

et al. 2016

J. Electrochem. Soc.

View full text Add to dashboard Cite

Electrochemical devices integrating a fuel cell with a hydrogen storage medium are able to function as secondary batteries. Batteries incorporating a partially oxygenated carbon anode with a RuO 2 /C cathode exhibit excellent reversibility, but their performance is not yet sufficient for secondary battery applications. This is due to excessive oxygenation of the anode, degradation of the cathode and the excess weight of the electrolyte membrane. In the present work, we addressed these challenges through various improvements in the design of a rechargeable proton-exchange membrane battery. These included coating the surface of a significantly oxygenated carbon anode (O/C atomic ratio 0.131) with carbon black nanoparticles, nanocrystallization of a carbon-free RuO 2 cathode (avg. crystallite size 1.1 nm) and the synthesis of an inorganic-organic composite electrolyte membrane. As a result of these optimizations, coulombic efficiencies of over 95% were achieved during charge/discharge over the voltage range of 0.0-1.5 V at 75 • C. The resulting device exhibited an initial capacity of 330 mAh g −1 and was stable over 300 cycles, with maximum energy and power densities of Hydrogen is a promising medium for the storage and supply of electricity through water-electrolysis/fuel-cell operation.1,2 The primary application of hydrogen in this context would be to store surplus power when the quantity of electricity produced by natural energy sources exceeds that required by a consumer.3-5 Rechargeable fuel cells capable of operating alternately in electrolyzer and fuel cell modes are recognized as the optimum systems because they are smaller and more compact than conventional systems based on isolated water electrolyzer and fuel cell units.6-8 The key technology necessary for such devices is hydrogen storage, which is currently accomplished via liquefaction and compression of the gas or by the physical or chemical adsorption of hydrogen atoms or molecules in/on materials such as metal or organic chemical hydrides.9,10 However, an energy input is required for these processes that in turn increases the overall cost. Furthermore, the hydrogen tanks and lines employed in such systems negatively impact their volumetric energy density.To mitigate these problems, rechargeable fuel-cell batteries (RFCBs) containing a hydrogen storage medium have been proposed. [11][12][13] During the operation of such batteries, hydrogen production, storage, supply and utilization processes must be conducted at the anode under the standard operational conditions of the cell, such as between room temperature and 80• C and at ambient pressure. In this context, oxygen-functionalized microporous carbons (MPCs) are promising hydrogen storage media, due to their excellent reversibility. 13 The redox pair between carbonyl (C=O) and phenol (C-OH) groups is one of the most important hydrogen carrier sites in such carbon anodes. The origin of this redox reaction is ascribed to the following equilibrium reaction between the two functional groups.This reaction...

show abstract

“…In contrast, only 1.5%, 2.0%, 5.6% and 8.9% of DCNQ molecules were involved in the bulk crystal, the DCNQ nanocrystal, the bulk-DCNQ/PPy mixture and the nano-DCNQ/PPy mixture, respectively. In previous studies, [28][29][30] the superior utilization rate of quinone molecules adsorbed on carbon matrices was reported to be 50% at 5.6 A g −1 and 62% at 5.0 A g −1 (Supplementary Table S1 in the Supplementary Information). In these works, the dispersion of quinone derivatives on the molecular level generates the enhanced electrochemical properties.…”

Section: Resultsmentioning

confidence: 99%

“…Therefore, quinone molecules have been grafted to or loaded on carbon materials with high specific area and conductivity. [28][29][30] Polymers containing quinone moieties have been synthesized and applied to charge storage. [31][32][33][34][35][36][37][38][39] Our group reported another approach for the effective use of quinone derivatives, that is, the incorporation of quinone derivatives in host conductive polymers.…”

Section: Introductionmentioning

confidence: 99%

Phase separation of composite materials through simultaneous polymerization and crystallization

2017

View full text Add to dashboard Cite

Composite materials have attracted much interest because of the emergent properties originating from the components. A variety of methods have been studied to control the morphology of composites based on noncrystalline polymers and crystalline materials. However, it is not easy to control complex morphologies, such as segregated sea-island structures, on the submicrometer scale. Polymerization induces crystallization, because supersaturation, which is required for crystallization, is achieved by the consumption of the monomer. Here we report a phase-separation approach based on simultaneous polymerization and crystallization as a new method for the morphological control of composite materials. Segregated polymer and organic crystal domains are obtained by polymerization of an organic monomer solution accompanied by simultaneous crystallization. The phase separation induced the generation of composite materials consisting of a redox-active quinone crystal and conductive polymer with a segregated structure on the submicrometer scale. The segregated composite of 2,3-dichloro-1,4-naphthoquinone and polypyrrole showed enhanced charge-storage properties based on the smooth redox reaction. The present phase-separation approach can be applied to a variety of functional segregated composite materials consisting of crystalline and polymer materials.

show abstract

Metal-free aqueous redox capacitor via proton rocking-chair system in an organic-based couple

Cited by 93 publications

References 24 publications

Pseudocapacitance of zeolite-templated carbon in organic electrolytes

Pseudocapacitance of zeolite-templated carbon in organic electrolytes

Design of a Rechargeable Fuel-Cell Battery with Enhanced Performance and Cyclability

Phase separation of composite materials through simultaneous polymerization and crystallization

Contact Info

Product

Resources

About