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Characteristics of ionic liquid-based electrolytes for chip type aluminum electrolytic capacitors  

Energy Technology Data Exchange (ETDEWEB)

Since ionic liquids (ILs) possess several attractive properties, including chemical and thermal stability, nonflammability, high ionic conductivity, and negligible vapor pressure, a new electrolyte system based on ILs has been proposed for chip type aluminum electrolytic capacitors. Four ILs based on imidazolium/pyrrolidinium cations and maleate/phthalate anions have been synthesized and their thermal stabilities have been examined. The 25wt.% solutions of the four ILs in gamma-butyrolactone (GBL) solvent were prepared as electrolytes of chip type aluminum electrolytic capacitors. The conductivity, sparking voltage and thermal stability of these electrolytes have been systematically investigated. The results revealed that the four IL-based electrolytes exhibited high conductivity. Furthermore, the conductivity of maleate anion-based electrolytes is higher than that of phthalate anion-based electrolytes, whereas the high-temperature durability of phthalate ...

2006-06-19

2

LiPF{sub 6}. Synthesis and stability in EC/DMC and PC/DMC mixtures; LiPF{sub 6}. Synthese et stabilite dans les melanges EC/DMC et PC/DMC  

Energy Technology Data Exchange (ETDEWEB)

Lithium hexa-fluoro-phosphate LiPF{sub 6} is recommended for the replacement of the toxic LiAsF{sub 6} and the explosive perchlorates (like LiClO{sub 4}) in rechargeable lithium electrochemical generators. The aim of this work is to develop a new method of synthesis of this salt and to check its stability with respect to carbonated solvents: ethylene carbonate (EC), propylene carbonate (PC) and dimethyl-carbonate (DMC) in already optimized EC/DMC and PC/DMC binary mixtures. Two methods using HPF{sub 6} are proposed: the first one uses the direct neutralization of this commercial acid by LiOH in aqueous, alcoholic or acetonitrile environment, while in the second one LiPF{sub 6} is obtained from pyridinium hexa-fluoro-phosphate synthesized from HPF{sub 6} using a new and simple protocol. (J.S.) 24 refs.

1996-12-31

3

Electrogenerated Chemiluminescence Sensor Based on Tris(2,2prime-bipyridine)ruthenium(II)-Immobilized Natural Clay and Ionic Liquid  

British Library Electronic Table of Contents (United Kingdom)

A novel electrogenerated chemiluminescence (ECL) sensor based on natural clay and ionic liquid was fabricated. Tris(2,2prime-bipyridine)ruthenium(II) (Ru(bpy)32+) was immobilized on natural clay surface through simple adsorption. An ECL sensor was prepared by mixing Ru(bpy)32+-incorporated clay, graphite powder and an ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate) as the binder. The electrochemical behavior and ECL of the immobilized Ru(bpy)32+ was investigated. It was observed that the ECL of immobilized Ru(bpy)32+ was activated by the ionic liquid. The proposed ECL sensor showed high sensitivity to tri-n-propylamine (TPrA) and the detection limit was found to be 20 pM. In addition, the ECL sensor displayed good stability for TPrA detection and long-term storage stability.

2010-01-01

4

Crystalline and Liquid Crystalline Organic-Inorganic Hybrid Salts with Cation-Sensitized Hexanuclear Molybdenum Cluster Complex Anion Luminescence  

British Library Electronic Table of Contents (United Kingdom)

Abstract The salts [Cnmim]2[Mo6Cl14] (mim = methylimidazolium; n = 4, 6, 12, 16, 18) have been obtained by reaction of CnmimCl with MoCl2. Thermal analysis shows the melting point decreases with increasing alkyl chain length of the cation. The imidazolium chloromolybdates(II) with n = 6-18 decompose above 340 C; [C18mim]2[Mo6Cl14] is thermally stable up to 390 C. All compounds are insensititve to the constituents of the atmosphere. Of the higher melting salts [Cnmim]2[Mo6Cl14] (n = 4, 6), high-quality single crystals could be obtained. Single-crystal X-ray structural analyses clearly show that the cluster complex anion [Mo6Cl14]2- has an electron-precise octahedral {Mo6} cluster. For [C4mim]2[Mo6Cl14], two polymorphs differing in the cation alkyl-side-chain conformation were obtained. The ...

2011-01-01

5

Sensitive detection of endocrine disrupters using ionic liquid - Single walled carbon nanotubes modified screen-printed based biosensors.  

Science.gov (United States)

Simple and low cost biosensor based on screen-printed electrode for sensitive detection of some alkylphenols was developed, by entrapment of HRP in a nanocomposite gel based on single-walled carbon nanotubes (SWCNTs) and 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF(6)]) ionic liquid. Raman and FTIR spectroscopy, CV and EIS studies demonstrate the interaction between SWCNTs and ionic liquid. The nanocomposite gel, SWCNT-[BMIM][PF(6)] provides to the modified sensor a considerable enhanced electrocatalytic activity toward hydrogen peroxide reduction. The HRP based biosensor exhibits high sensitivity and good stability, allowing a detection of the alkylphenols at an applied potential of -0.2V vs. Ag/AgCl, in linear range from 5.5 to 97.7?M for 4-t-octylphenol and respectively, between 5.5 and 140?M for 4-n-nonylphenol, with a response time of about 5s. The detection limit was 1.1?M for 4-t-octylphenol, and respectively 0.4?M for 4-n-nonylphenol (S/N=3). ...

2011-07-19

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Electrolyte for high voltage Li/LiMn{sub 1.9}Co{sub 0.1}O{sub 4} cells  

Energy Technology Data Exchange (ETDEWEB)

An electrolyte for high voltage lithium metal anode cells must simultaneously satisfy at least the following requirements; (i) high cycling efficiency on the lithium metal anode; (ii) higher oxidation potential than the charging voltage, and (iii) high specific conductivity. We have examined various electrolytes for lithium metal anode cells using a high voltage cathode, LiMn{sub 1.9}Co{sub 0.1}O{sub 4}. Of the electrolytes resistant to high voltage that we used, a system containing 60 to 90 vol.% of dimethyl carbonate (DMC) mixed with ethylene carbonate (EC) and 1.0 M lithium hexafluorophosphate (LiPF{sub 6}) provided the best cycling efficiency on a lithium metal anode, as well as a high specific conductivity around 10 mS cm{sup -1} at 20 C. (orig.)

1997-10-01