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Liquid Electrolyte (liquid + electrolyte)
Kinds of Liquid Electrolyte Selected AbstractsNew Type High Efficient Quasi-Solid-State Ionic Liquid Electrolyte for Dye-Sensitized Solar CellsCHINESE JOURNAL OF CHEMISTRY, Issue 11 2007Xu PAN Abstract For the fist time the preparation of a mostly solid-state high efficient electro-conductive material comprising 1-methyl-3-propylimidazolium iodide (MPII), benzimidazole (BI), iodine and lithium iodide was reported. In this electrolyte, BI acts as not only additives but also gelators. With its significant electrochemical properties, an overall efficiency of 3.07% was achieved under AM 1.5 (100 mW/cm2). [source] Effects of TiO2 Film on the Performance of Dye-sensitized Solar Cells Based on Ionic Liquid ElectrolyteCHINESE JOURNAL OF CHEMISTRY, Issue 12 2005Xu Pan Abstract Photo correlation spectroscopy was used to measure the particle size distribution of TiO2 films. Other parameters, such as porosity, BET surface area, average pore size, crystallite size D101, distribution of pore size etc. were also measured. The effects of these parameters on the ionic liquid based dye-sensitized solar cells (DSC) were studied. It was concluded that the particle size distribution of nanocrystalline TiO2 played an important role on the performance of DSC. The narrow particle size distribution of nanocrystalline TiO2 increased the efficiency of DSC, while the wide distribution decreased the efficiency of DSC. From the result above, it was also concluded that the photo correlation spectroscopy was a good method to identify the performance of TiO2 films. Based on electrochemical impedance spectroscopy, we found that the particle size distribution could affect the electronic contact between the TiO2 layers as well. The narrow particle size distribution made the electronic contact between TiO2 layers better than the wide particle size distribution of the TiO2 films, and then better the electronic contact, higher the efficiency of the DSC. [source] Solvent-Free Ionic Liquid Electrolytes for Mesoscopic Dye-Sensitized Solar CellsADVANCED FUNCTIONAL MATERIALS, Issue 14 2009Shaik M. Zakeeruddin Abstract Ionic liquids have been identified as a new class of solvent that offers opportunities to move away from the traditional solvents. The physical-chemical properties of ionic liquids can be tuned and controlled by tailoring their structures. The typical properties of ionic liquids, such as non-volatility, electrochemical stability and high conductivity, render them attractive as electrolytes for dye-sensitized solar cells. However, the high viscosity of ionic liquids leads to mass transport limitations on the photocurrents in the solar cells at full sunlight intensity, but the contribution of a Grotthous-type exchange mechanism in these viscous electrolytes helps to alleviate these diffusion problems. This article discusses recent developments in the field of high-performance dye-sensitized solar cells with ionic liquid-based electrolytes and their characterization by electrochemical impedance analysis. [source] Novel and Efficient Organic Liquid Electrolytes for Dye-Sensitized Solar Cells Based on a Ru(II) Terpyridyl Complex Photosensitizer.CHEMINFORM, Issue 11 2004Kohjiro Hara Abstract For Abstract see ChemInform Abstract in Full Text. [source] The Influence of Mass Transfer on a Porous Fuel Cell ElectrodeFUEL CELLS, Issue 1-2 2004Y.-P. Sun Abstract A one-dimensional model for a porous fuel cell electrode using a liquid electrolyte with dissolved reactant is presented. The model consists of a Poisson, second-order ordinary differential equation, describing the effect of the electric field and a one-dimensional; Fickian diffusion, second-order ordinary differential equation describing the concentration variation associated with diffusion. The model accounts for mass transport and heterogeneous electrochemical reaction. The solution of this model is by the approximate Adomian polynomial method and is used to determine lateral distributions of concentration, overpotential and current density and overall cell polarisation. The model is used to simulate the effects of important system and operating parameters, i.e. local diffusion rates, and mass transport coefficients and electrode polarisation behaviour. [source] Towards Optimization of Materials for Dye-Sensitized Solar CellsADVANCED MATERIALS, Issue 45 2009Yanhong Luo Abstract Dye-sensitized solar cells (DSCs) have received widespread attention owing to their low cost, easy fabrication, and relatively high solar-to-electricity conversion efficiency. Based on the nanocrystalline TiO2 electrode, Ru-polypyridyl-complex dye, liquid electrolyte with I,/I3, redox couple, and Pt counter electrode, DSCs have already exhibited an efficiency above 11% and offer an appealing alternative to conventional solar cells. However, further improvements in the efficiency and stability are still required to drive forward practical application. These improvements require the cooperative optimization of the component materials, structures, and processing techniques. In this Research News article, recent progress in DSCs made by our group are reviewed, including some novel approaches to the synthesis of solid-state and environmentally friendly electrolytes, the fabrication of alternative low-cost nanostructural electrodes, and the control of recombination at the interfaces. [source] The Zwitterion Effect in Ionic Liquids: Towards Practical Rechargeable Lithium-Metal Batteries,ADVANCED MATERIALS, Issue 20 2005N. Byrne Practical lithium-metal batteries are the ultimate goal of battery researchers. The addition of a zwitterionic compound (see Figure) to an ionic liquid electrolyte doped with a lithium salt results in a 100% enhancement of the current densities achieved in the cycling of a lithium-metal cell. This phenomenon arises due to increased lithium-ion mobility or a reduced solid electrolyte interphase layer resistance. [source] Fabrication and properties of crosslinked poly(propylene carbonate maleate) gel polymer electrolyte for lithium-ion batteryJOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2010Xiaoyuan Yu Abstract The poly(propylene carbonate maleate) (PPCMA) was synthesized by the terpolymerization of carbon dioxide, propylene oxide, and maleic anhydride. The PPCMA polymer can be readily crosslinked using dicumyl peroxide (DCP) as crosslinking agent and then actived by absorbing liquid electrolyte to fabricate a novel PPCMA gel polymer electrolyte for lithium-ion battery. The thermal performance, electrolyte uptake, swelling ratio, ionic conductivity, and lithium ion transference number of the crosslinked PPCMA were then investigated. The results show that the Tg and the thermal stability increase, but the absorbing and swelling rates decrease with increasing DCP amount. The ionic conductivity of the PPCMA gel polymer electrolyte firstly increases and then decreases with increasing DCP ratio. The ionic conductivity of the PPCMA gel polymer electrolyte with 1.2 wt % of DCP reaches the maximum value of 8.43 × 10,3 S cm,1 at room temperature and 1.42 × 10,2 S cm,1 at 50°C. The lithium ion transference number of PPCMA gel polymer electrolyte is 0.42. The charge/discharge tests of the Li/PPCMA GPE/LiNi1/3Co1/3Mn1/3O2 cell were evaluated at a current rate of 0.1C and in voltage range of 2.8,4.2 V at room temperature. The results show that the initial discharge capacity of Li/PPCMA GPE/LiNi1/3Co1/3Mn1/3 O2 cell is 115.3 mAh g,1. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Solid polymer electrolytes III: Preparation, characterization, and ionic conductivity of new gelled polymer electrolytes based on segmented, perfluoropolyether-modified polyurethaneJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 4 2002Chi-Chang Chen Abstract New segmented polyurethanes with perfluoropolyether (PFPE) and poly(ethylene oxide) blocks were synthesized from a fluorinated macrodiol mixed with poly(ethylene glycol) (PEG) in different ratios as a soft segment, 2,4-toluene diisocyanate as a hard segment, and ethylene glycol as a chain extender. Fourier transform infrared, NMR, and thermal analysis [differential scanning calorimetry and thermogravimetric analysis (TGA)] were used to characterize the structures of these copolymers. The copolymer films were immersed in a liquid electrolyte (1 M LiClO4/propylene carbonate) to form gel-type electrolytes. The ionic conductivities of these polymer electrolytes were investigated through changes in the copolymer composition and content of the liquid electrolyte. The relative molar ratio of PFPE and PEG in the copolymer played an important role in the conductivity and the capacity to retain the liquid electrolyte solution. The copolymer with a 50/50 PFPE/PEG ratio, having the lowest decomposition temperature shown by TGA, exhibited the highest ionic conductivity and lowest activation energy for ion transportation. The conductivities of these systems were about 10,3 S cm,1 at room temperature and 10,2 S cm,1 at 70 °C; the films immersed in the liquid electrolyte with an increase of 70 wt % were homogenous with good mechanical properties. © 2002 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 486,495, 2002; DOI 10.1002/pola.10119 [source] Single Radiation-Induced Grafting Method for the Preparation of Two Proton- and Lithium Ion-Conducting MembranesMACROMOLECULAR MATERIALS & ENGINEERING, Issue 8 2006Mohamed Mahmoud Nasef Abstract Summary: Two distinct types of polymer electrolyte membranes for conducting protons and lithium ions have been prepared by a radiation-induced grafting method. The polymer electrolyte precursor (PVDF- g -PS) is obtained by the simultaneous grafting of styrene onto poly(vinylidene fluoride) (PVDF) followed by one of two specific treatments. This includes sulfonation with a chlorosulfonic acid/dichloromethane mixture to obtain proton (H+)-conducting membranes, or activation with LiPF6/EC/DC liquid electrolyte to obtain lithium ion (Li+)-conducting membranes. The chemical structure of the obtained electrolyte membranes is verified by FT-IR spectroscopy. Differential scanning calorimetry is used to examine the changes in the crystallinity and the thermal properties of both electrolyte membranes during the preparation process. The thermal stability of both electrolyte membranes is also evaluated using thermal gravimetrical analysis. The obtained polymer electrolyte membranes achieve superior conductivity values: 1.61,×,10,3 S,·,cm,1 for Li+ and 5.95,×,10,2 S,·,cm,1 for H+ at room temperature at a polystyrene content of 50%. The results of this work suggest that high quality H+ - and Li+ -conducting membranes can be obtained using a single radiation-induced grafting method. Schematic representation of the single root for preparation of Li+ - and H+ -conducting membranes started by radiation-induced grafting of styrene onto a PVDF film followed by chemical treatment. [source] A Thermoplastic Gel Electrolyte for Stable Quasi-Solid-State Dye-Sensitized Solar Cells,ADVANCED FUNCTIONAL MATERIALS, Issue 15 2007H. Wu Abstract Dye-sensitized solar cells (DSSCs) are receiving considerable attention as low-cost alternatives to conventional solar cells. In DSSCs based on liquid electrolytes, a photoelectric efficiency of 11,% has been achieved, but potential problems in sealing the cells and the low long-term stability of these systems have impeded their practical use. Here, we present a thermoplastic gel electrolyte (TPGE) as an alternative to the liquid electrolytes used in DSSCs. The TPGE exhibits a thermoplastic character, high conductivity, long-term stability, and can be prepared by a simple and convenient protocol. The viscosity, conductivity, and phase state of the TPGE can be controlled by tuning the composition. Using 40,wt,% poly(ethylene glycol) (PEG) as the polymeric host, 60,wt,% propylene carbonate (PC) as the solvent, and 0.65,M KI and 0.065,M I2 as the ionic conductors, a TPGE with a conductivity of 2.61,mS,cm,2 is prepared. Based on this TPGE, a DSSC is fabricated with an overall light-to-electrical-energy conversion efficiency of 7.22,% under 100,mW,cm,2 irradiation. The present findings should accelerate the widespread use of DSSCs. [source] Donor/Conductor/Acceptor Triads Spatially Organized on the Micrometer-Length Scale: An Alternative Approach to Photovoltaic CellsCHEMISTRY - A EUROPEAN JOURNAL, Issue 2 2007Francesc Abstract We have used porous anodised Al2O3 membranes as inert matrix for constructing and organizing spatially ternary donor/conductor/acceptor (DCA) systems exhibiting photovoltaic cell activity on the micrometric-length scale. These DCA triads were built stepwise by first growing a conducting polymer inside the membrane pores, thus forming nanorods that completely fill the internal pore space of the membrane. Then, an electron donor and an electron acceptor were adsorbed one on each side of the membrane, so that they were separated by a distance equal to the membrane thickness (ca. 60,,m), but electronically connected through the conductive polymer. When this device was placed between two electrodes and irradiated with visible light, electrons jumped from the donor molecule, crossed the membrane from side to side through the conductive polymer (a journey of about 60,,m!) until they finally reach the acceptor molecule. In so doing, an electric voltage was generated between the two electrodes, capable of maintaining an electric current flow from the membrane to an external circuit. Our DCA device constitutes the proof of a novel concept of photovoltaic cells, since it is based on the spatial organization at the micrometric scale of complementary, but not covalently linked, electron-donor and electron-acceptor organic species. Thus, our cell is based in translating photoinduced electron transfer between donors and acceptors, which is known to occur at the molecular nanometric scale, to the micrometric range in a spatially organised system. In addition our cell does not need the use of liquid electrolytes in order to operate, which is one of the main drawbacks in dye-sensitised solar cells. [source] | |||||||||||||||||||||||||