On the Consequences of Clausius-Duhem Inequality for Electrolyte Solutions

NASA Astrophysics Data System (ADS)

Reis, Martina; Bassi, Adalberto Bono Maurizio Sacchi

2014-03-01

Based on the fundamentals of thermo-statics, non-equilibrium thermodynamics theories frequently employ an entropy inequality, where the entropy flux is collinear to the heat flux, and the entropy supply is proportional to the energy supply. Although this assumption is suitable for many material bodies, e.g. heat-conducting viscous fluids, there is a class of materials for which these assumptions are not valid. By assuming that the entropy flux and the entropy supply are constitutive quantities, in this work it is demonstrated that the entropy flux for a reacting ionic mixture of non-volatile solutes presents a non-collinear term due to the diffusive fluxes. The consequences of the collinearity between the entropy flux and the heat flux, as well as the proportionality of the entropy supply and the energy supply on the stability of chemical systems are also investigated. Furthermore, by considering an electrolyte solution of non-volatile solutes in phase equilibrium with water vapor, and the constitutive nature of the entropy flux, the stability of a vapor-electrolyte solution interface is studied. Despite this work only deals with electrolyte solutions, the results presented can be easily extended to more complex chemical reacting systems. The first author acknowledges financial support from CNPq (National Counsel of Technological and Scientific Development).

Apparent Ionic Charge in Electrolyte and Polyelectrolyte Solutions

ERIC Educational Resources Information Center

Magdelenat, H.; And Others

1978-01-01

Compares average displacements of charged particles under thermal motion alone with those obtained by the action of an external electric field to develop a concept of "apparent charge" to approximate actual structural charge in an electrolyte solution. (SL)

Electrolyte for batteries with regenerative solid electrolyte interface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiao, Jie; Lu, Dongping; Shao, Yuyan

2017-08-01

An energy storage device comprising: an anode; and a solute-containing electrolyte composition wherein the solute concentration in the electrolyte composition is sufficiently high to form a regenerative solid electrolyte interface layer on a surface of the anode only during charging of the energy storage device, wherein the regenerative layer comprises at least one solute or solvated solute from the electrolyte composition.

Polynuclear Speciation of Trivalent Cations near the Surface of an Electrolyte Solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bera, Mrinal K.; Antonio, Mark R.

Despite long-standing efforts, there is no agreed upon structural model for electrolyte solutions at air-liquid interfaces. We report the simultaneous detection of the near-surface and bulk coordination environments of a trivalent metal cation (europium) in an aqueous solution by use of X-ray absorption spectroscopy. Within the first few nanometers of the liquid surface, the cations exhibit oxygen coordination typical of inner-sphere hydration of an aquated Eu3+ cation. Beyond that, outer-sphere ion-ion correlations are observed that are otherwise not present in the bulk electrolyte. The combination of near-surface and bulk sensitivities to probe metal ion speciation in electrolyte solutions is achievedmore » by detecting electron-yield and X-ray fluorescence signals from an inverted pendant drop. The results provide new knowledge about the near-surface chemistry of aqueous solutions of relevance to aerosols and ion transport processes in chemical separations and biological systems.« less

Background electrolytes and pH effects on selenate adsorption using iron-impregnated granular activated carbon and surface binding mechanisms.

PubMed

Zhang, Ning; Gang, Daniel Dianchen; McDonald, Louis; Lin, Lian-Shin

2018-03-01

Iron-impregnated granular activated carbon (Fe-GAC) has been shown effective for selenite adsorptive removal from aqueous solutions, but similar effectiveness was not observed with selenate. This study examined the effects of background electrolytes and pH on selenate adsorption on to Fe-GAC, and surface bindings to elucidate the selenate adsorption mechanisms. The decrease magnitude of selenate adsorption capacity under three background electrolytes followed the order: LiCl > NaCl > KCl, as ionic strength increased from 0.01 to 0.1 M. Larger adsorption capacity differences among the three electrolytes were observed under the higher ionic strengths (0.05 and 0.1 M) than those under 0.01 M. Multiplet peak fittings of high resolution X-ray photoelectron spectra for O1s and Fe2p 3/2 indicated the presence of iron (III) on adsorbent surface. pH variations during the adsorbent preparation within 3-8 in NaCl solutions did not cause appreciable changes in the iron redox state and composition. Raman spectra showed the formation of both monodentate and bidentate inner sphere complexes under pHs <7 and a mixture of outer sphere and inner sphere complexes at pH 8. These results explained the lower selenate adsorption under alkaline conditions. Mechanisms for monodentate and bidentate formations and a stable six-member ring structure were proposed. Two strategies were recommended for modifying Fe-GAC preparation procedure to enhance the selenate adsorption: (1) mixed-metal oxide coatings to increase the point of zero charge (pH zpc ); and (2) ferrous iron coating to initially reduce selenate followed by selenite adsorption. Copyright © 2017 Elsevier Ltd. All rights reserved.

A molecular Debye-Hückel theory and its applications to electrolyte solutions: The size asymmetric case

DOE PAGES

Xiao, Tiejun; Song, Xueyu

2017-03-28

We developed a molecular Debye-Hückel theory for electrolyte solutions with size asymmetry, where the dielectric response of an electrolyte solution is described by a linear combination of Debye-Hückel-like response modes. Furthermore, as the size asymmetry of an electrolyte solution leads to a charge imbalanced border zone around a solute, the dielectric response to the solute is characterized by two types of charge sources, namely, a bare solute charge and a charge distribution due to size asymmetry. These two kinds of charge sources are screened by the solvent differently, our theory presents a method to calculate the mean electric potential asmore » well as the electrostatic contributions to thermodynamic properties. Finally, the theory was successfully applied to binary as well as multi-component primitive models of electrolyte solutions.« less

Surface tensions of inorganic multicomponent aqueous electrolyte solutions and melts.

PubMed

Dutcher, Cari S; Wexler, Anthony S; Clegg, Simon L

2010-11-25

A semiempirical model is presented that predicts surface tensions (σ) of aqueous electrolyte solutions and their mixtures, for concentrations ranging from infinitely dilute solution to molten salt. The model requires, at most, only two temperature-dependent terms to represent surface tensions of either pure aqueous solutions, or aqueous or molten mixtures, over the entire composition range. A relationship was found for the coefficients of the equation σ = c(1) + c(2)T (where T (K) is temperature) for molten salts in terms of ion valency and radius, melting temperature, and salt molar volume. Hypothetical liquid surface tensions can thus be estimated for electrolytes for which there are no data, or which do not exist in molten form. Surface tensions of molten (single) salts, when extrapolated to normal temperatures, were found to be consistent with data for aqueous solutions. This allowed surface tensions of very concentrated, supersaturated, aqueous solutions to be estimated. The model has been applied to the following single electrolytes over the entire concentration range, using data for aqueous solutions over the temperature range 233-523 K, and extrapolated surface tensions of molten salts and pure liquid electrolytes: HCl, HNO(3), H(2)SO(4), NaCl, NaNO(3), Na(2)SO(4), NaHSO(4), Na(2)CO(3), NaHCO(3), NaOH, NH(4)Cl, NH(4)NO(3), (NH(4))(2)SO(4), NH(4)HCO(3), NH(4)OH, KCl, KNO(3), K(2)SO(4), K(2)CO(3), KHCO(3), KOH, CaCl(2), Ca(NO(3))(2), MgCl(2), Mg(NO(3))(2), and MgSO(4). The average absolute percentage error between calculated and experimental surface tensions is 0.80% (for 2389 data points). The model extrapolates smoothly to temperatures as low as 150 K. Also, the model successfully predicts surface tensions of ternary aqueous mixtures; the effect of salt-salt interactions in these calculations was explored.

Potential of Zero Charge and Its Temperature Derivative for Au(111) Electrode|Alkanethiol SAM|1.0 M Aqueous Electrolyte Solution Interfaces: Impact of Electrolyte Solution Ionic Strength and Its Effect on the Structure of the Modified Electrode|Electrolyte Solution Interface

DOE PAGES

Smalley, John F.

2017-04-06

In this study, we demonstrate how small and rapid temperature perturbations (produced by the indirect laser-induced temperature jump (ILIT) technique) of solid metal electrode|electrolyte solution interfaces may be used to determine the potential of zero (total) charge (E pzc) and its temperature derivativemore » $$\\left(\\frac{dEpzc}{dT}\\right)$$ of Au(111) electrode surfaces modified by alkanethiol self-assembled monolayers in contact with high ionic strength (i.e., 1.0 M) aqueous electrolyte solutions. The E pzc’s measured for two different types of SAMs (made from either HS(CH 2) n-1CH 3 (5 ≤ n ≤ 12, E pzc = -(0.99 ± 0.12) V vs SSCE) or HS(CH 2) nOH (3 ≤ n ≤ 16, E pzc = (0.46 ± 0.22) V vs SSCE)) are considerably different than those measured previously at much lower electrolyte solution ionic strengths. For mixed monolayers made from both HS(CH 2) n-1CH 3 and HS(CH 2) nFc (where Fc refers to ferrocene), the difference in Epzc decreases as a function of the surface concentration of the Fc moiety (i.e., [Fc]), and it completely disappears at a surprisingly small [Fc] (~4.0 × 10 –11 mol cm –2). These observations for the Au(111)|hydrophobic (neat and mixed) SAM|aqueous electrolyte solution interfaces, along with the surface potentials (g Sml(dip)) evaluated for the contacting electrolyte solution surfaces of these interfaces, are consistent with a structure for the water molecule components of these surfaces where there is a net orientation of the dipoles of these molecules. Accordingly, the negative (oxygen) ends of these molecules point toward the SAM surface. The positive values of g Sml(dip) evaluated for hydrophilic SAM (e.g., made from HS(CH 2) nOH)|aqueous electrolyte solution interfaces) also indicate that the structure of these interfaces is similar to that of the hydrophobic interfaces. However, g Sml(dip) decreases with increasing ionic strength for the hydrophilic interfaces, while it increases with increasing ionic strength for

Large-current-controllable carbon nanotube field-effect transistor in electrolyte solution

NASA Astrophysics Data System (ADS)

Myodo, Miho; Inaba, Masafumi; Ohara, Kazuyoshi; Kato, Ryogo; Kobayashi, Mikinori; Hirano, Yu; Suzuki, Kazuma; Kawarada, Hiroshi

2015-05-01

Large-current-controllable carbon nanotube field-effect transistors (CNT-FETs) were fabricated with mm-long CNT sheets. The sheets, synthesized by remote-plasma-enhanced CVD, contained both single- and double-walled CNTs. Titanium was deposited on the sheet as source and drain electrodes, and an electrolyte solution was used as a gate electrode (solution gate) to apply a gate voltage to the CNTs through electric double layers formed around the CNTs. The drain current came to be well modulated as electrolyte solution penetrated into the sheets, and one of the solution gate CNT-FETs was able to control a large current of over 2.5 A. In addition, we determined the transconductance parameter per tube and compared it with values for other CNT-FETs. The potential of CNT sheets for applications requiring the control of large current is exhibited in this study.

Electrolyte solutions including a phosphoranimine compound, and energy storage devices including same

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klaehn, John R.; Dufek, Eric J.; Rollins, Harry W.

An electrolyte solution comprising at least one phosphoranimine compound and a metal salt. The at least one phosphoranimine compound comprises a compound of the chemical structure ##STR00001## where X is an organosilyl group or a tert-butyl group and each of R.sup.1, R.sup.2, and R.sup.3 is independently selected from the group consisting of an alkyl group, an aryl group, an alkoxy group, or an aryloxy group. An energy storage device including the electrolyte solution is also disclosed.

Electrochemical Preparation of Polyaniline Nanowires with the Used Electrolyte Solution Treated with the Extraction Process and Their Electrochemical Performance.

PubMed

Wu, Ying; Wang, Jixiao; Ou, Bin; Zhao, Song; Wang, Zhi; Wang, Shichang

2018-02-12

Electrochemical polymerization of aniline is one of the most promising methods to prepare polyaniline (PANI) materials. However, during this process, the electrolyte solution must be replaced after electropolymerization of a certain time because of the generation and the accumulation of the by-products, which have significant effects on the morphology, purity and properties of PANI products. Treatment and recycling of the used electrolyte solution are worthwhile to study to reduce the high treatment cost of the used electrolyte solution containing aniline and its polymerization by-products. Here, the composition of the used electrolyte solution was separated and determined by high performance liquid chromatography coupled with diode array detection (HPLC-DAD) in the range of ultraviolet and visible (UV-Vis) light. The analysis results revealed that the used electrolyte solution consisted of aniline, p-hydroquinone (HQ), p-benzoquinone (BQ), co-oligomers of aniline and p-benzoquinone (CAB) and acid. Then, n-octanol and 2-octanone were selected as extracts to remove HQ, BQ and CAB from the used electrolyte solution. Following that, the recycled electrolyte solution was prepared by adjusting the concentration of aniline and acid of the aqueous phase, and the electrochemical polymerization process was conducted. Finally, the obtained PANI was characterized by scanning electron microscope (SEM) and electrochemical methods. The experimental results clearly demonstrate that the morphology and specific capacitance of PANI produced from the recycled electrolyte solution can be recovered completely. This research paves the way for reusing the used electrolyte solution for aniline electrochemical polymerization.

Electrochemical Preparation of Polyaniline Nanowires with the Used Electrolyte Solution Treated with the Extraction Process and Their Electrochemical Performance

PubMed Central

Wu, Ying; Wang, Jixiao; Ou, Bin; Zhao, Song; Wang, Zhi; Wang, Shichang

2018-01-01

Electrochemical polymerization of aniline is one of the most promising methods to prepare polyaniline (PANI) materials. However, during this process, the electrolyte solution must be replaced after electropolymerization of a certain time because of the generation and the accumulation of the by-products, which have significant effects on the morphology, purity and properties of PANI products. Treatment and recycling of the used electrolyte solution are worthwhile to study to reduce the high treatment cost of the used electrolyte solution containing aniline and its polymerization by-products. Here, the composition of the used electrolyte solution was separated and determined by high performance liquid chromatography coupled with diode array detection (HPLC-DAD) in the range of ultraviolet and visible (UV-Vis) light. The analysis results revealed that the used electrolyte solution consisted of aniline, p-hydroquinone (HQ), p-benzoquinone (BQ), co-oligomers of aniline and p-benzoquinone (CAB) and acid. Then, n-octanol and 2-octanone were selected as extracts to remove HQ, BQ and CAB from the used electrolyte solution. Following that, the recycled electrolyte solution was prepared by adjusting the concentration of aniline and acid of the aqueous phase, and the electrochemical polymerization process was conducted. Finally, the obtained PANI was characterized by scanning electron microscope (SEM) and electrochemical methods. The experimental results clearly demonstrate that the morphology and specific capacitance of PANI produced from the recycled electrolyte solution can be recovered completely. This research paves the way for reusing the used electrolyte solution for aniline electrochemical polymerization. PMID:29439514

Order of wetting transitions in electrolyte solutions.

PubMed

Ibagon, Ingrid; Bier, Markus; Dietrich, S

2014-05-07

For wetting films in dilute electrolyte solutions close to charged walls we present analytic expressions for their effective interface potentials. The analysis of these expressions renders the conditions under which corresponding wetting transitions can be first- or second-order. Within mean field theory we consider two models, one with short- and one with long-ranged solvent-solvent and solvent-wall interactions. The analytic results reveal in a transparent way that wetting transitions in electrolyte solutions, which occur far away from their critical point (i.e., the bulk correlation length is less than half of the Debye length) are always first-order if the solvent-solvent and solvent-wall interactions are short-ranged. In contrast, wetting transitions close to the bulk critical point of the solvent (i.e., the bulk correlation length is larger than the Debye length) exhibit the same wetting behavior as the pure, i.e., salt-free, solvent. If the salt-free solvent is governed by long-ranged solvent-solvent as well as long-ranged solvent-wall interactions and exhibits critical wetting, adding salt can cause the occurrence of an ion-induced first-order thin-thick transition which precedes the subsequent continuous wetting as for the salt-free solvent.

Sensitive bridge circuit measures conductance of low-conductivity electrolyte solutions

NASA Technical Reports Server (NTRS)

Schmidt, K.

1967-01-01

Compact bridge circuit measures sensitive and accurate conductance of low-conductivity electrolyte solutions. The bridge utilizes a phase sensitive detector to obtain a linear deflection of the null indicator relative to the measured conductance.

The Interplay of Al and Mg Speciation in Advanced Mg Battery Electrolyte Solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

See, Kimberly A.; Chapman, Karena W.; Zhu, Lingyang

2016-01-13

Mg batteries are an attractive alternative to Li-based energy storage due to the possibility of higher volumetric capacities with the added advantage of using sustainable materials. A promising emerging electrolyte for Mg batteries is the magnesium aluminum chloride complex (MACC) which shows high Mg electrodeposition and stripping efficiencies and relatively high anodic stabilities. As prepared, MACC is inactive with respect to Mg deposition; however, efficient Mg electrodeposition can be achieved following an electrolytic conditioning process. Through the use of Raman spectroscopy, surface enhanced Raman spectroscopy, 27Al and 35Cl nuclear magnetic resonance spectroscopy, and pair distribution function analysis, we explore themore » active vs inactive complexes in the MACC electrolyte and demonstrate the codependence of Al and Mg speciation. These techniques report on significant changes occurring in the bulk speciation of the conditioned electrolyte relative to the as-prepared solution. Analysis shows that the active Mg complex in conditioned MACC is very likely the [Mg2(μ–Cl)3·6THF]+ complex that is observed in the solid state structure. Additionally, conditioning creates free Cl– in the electrolyte solution, and we suggest the free Cl– adsorbs at the electrode surface to enhance Mg electrodeposition.« less

Enhanced Performance of PbS-quantum-dot-sensitized Solar Cells via Optimizing Precursor Solution and Electrolytes

NASA Astrophysics Data System (ADS)

Tian, Jianjun; Shen, Ting; Liu, Xiaoguang; Fei, Chengbin; Lv, Lili; Cao, Guozhong

2016-03-01

This work reports a PbS-quantum-dot-sensitized solar cell (QDSC) with power conversion efficiency (PCE) of 4%. PbS quantum dots (QDs) were grown on mesoporous TiO2 film using a successive ion layer absorption and reaction (SILAR) method. The growth of QDs was found to be profoundly affected by the concentration of the precursor solution. At low concentrations, the rate-limiting factor of the crystal growth was the adsorption of the precursor ions, and the surface growth of the crystal became the limiting factor in the high concentration solution. The optimal concentration of precursor solution with respect to the quantity and size of synthesized QDs was 0.06 M. To further increase the performance of QDSCs, the 30% deionized water of polysulfide electrolyte was replaced with methanol to improve the wettability and permeability of electrolytes in the TiO2 film, which accelerated the redox couple diffusion in the electrolyte solution and improved charge transfer at the interfaces between photoanodes and electrolytes. The stability of PbS QDs in the electrolyte was also improved by methanol to reduce the charge recombination and prolong the electron lifetime. As a result, the PCE of QDSC was increased to 4.01%.

Enhanced Performance of PbS-quantum-dot-sensitized Solar Cells via Optimizing Precursor Solution and Electrolytes.

PubMed

Tian, Jianjun; Shen, Ting; Liu, Xiaoguang; Fei, Chengbin; Lv, Lili; Cao, Guozhong

2016-03-15

This work reports a PbS-quantum-dot-sensitized solar cell (QDSC) with power conversion efficiency (PCE) of 4%. PbS quantum dots (QDs) were grown on mesoporous TiO2 film using a successive ion layer absorption and reaction (SILAR) method. The growth of QDs was found to be profoundly affected by the concentration of the precursor solution. At low concentrations, the rate-limiting factor of the crystal growth was the adsorption of the precursor ions, and the surface growth of the crystal became the limiting factor in the high concentration solution. The optimal concentration of precursor solution with respect to the quantity and size of synthesized QDs was 0.06 M. To further increase the performance of QDSCs, the 30% deionized water of polysulfide electrolyte was replaced with methanol to improve the wettability and permeability of electrolytes in the TiO2 film, which accelerated the redox couple diffusion in the electrolyte solution and improved charge transfer at the interfaces between photoanodes and electrolytes. The stability of PbS QDs in the electrolyte was also improved by methanol to reduce the charge recombination and prolong the electron lifetime. As a result, the PCE of QDSC was increased to 4.01%.

Thermodynamic properties of gases dissolved in electrolyte solutions.

NASA Technical Reports Server (NTRS)

Tiepel, E. W.; Gubbins, K. E.

1973-01-01

A method based on perturbation theory for mixtures is applied to the prediction of thermodynamic properties of gases dissolved in electrolyte solutions. The theory is compared with experimental data for the dependence of the solute activity coefficient on concentration, temperature, and pressure; calculations are included for partial molal enthalpy and volume of the dissolved gas. The theory is also compared with previous theories for salt effects and found to be superior. The calculations are best for salting-out systems. The qualitative feature of salting-in is predicted by the theory, but quantitative predictions are not satisfactory for such systems; this is attributed to approximations made in evaluating the perturbation terms.

Measuring the state of charge of the electrolyte solution in a vanadium redox flow battery using a four-pole cell device

NASA Astrophysics Data System (ADS)

Ngamsai, Kittima; Arpornwichanop, Amornchai

2015-12-01

The decrease in the efficiency and capacity of a vanadium redox flow battery (VRB) caused by an electrolyte imbalance is an important impediment to its long-term operation. Knowing the state of charge (SOC) of an electrolyte solution can quantify the level of the electrolyte imbalance in the VRB. In this study, a four-pole cell device is devised and employed to predict the SOC. The proposed method directly measures the ionic resistance of the electrolyte solution and is sufficiently precise to be applied in real-time mode. Experimental studies on the effects of the operating current on the four-pole cell and the concentrations of vanadium and sulfuric acid in the electrolyte solution are carried out. The results show that the four-pole cell method can be utilized to measure the electrolyte SOC. The concentrations of vanadium and sulfuric acid in the electrolyte solution affect the ionic resistance of the solution. Regarding the capacity and efficiency of the VRB system, the results indicate that the electrical charge is determined from the concentration of vanadium and that the cell voltage depends on the concentration of sulfuric acid in the electrolyte solution. The decreased vanadium concentration and increased sulfuric acid concentration improves the cell voltage efficiency.

Fluctuation-enhanced electric conductivity in electrolyte solutions

DOE PAGES

Péraud, Jean-Philippe; Nonaka, Andrew J.; Bell, John B.; ...

2017-09-26

In this work, we analyze the effects of an externally applied electric field on thermal fluctuations for a binary electrolyte fluid. We show that the fluctuating Poisson–Nernst–Planck (PNP) equations for charged multispecies diffusion coupled with the fluctuating fluid momentum equation result in enhanced charge transport via a mechanism distinct from the well-known enhancement of mass transport that accompanies giant fluctuations. Although the mass and charge transport occurs by advection by thermal velocity fluctuations, it can macroscopically be represented as electrodiffusion with renormalized electric conductivity and a nonzero cation–anion diffusion coefficient. Specifically, we predict a nonzero cation–anion Maxwell– Stefan coefficient proportionalmore » to the square root of the salt concentration, a prediction that agrees quantitatively with experimental measurements. The renormalized or effective macroscopic equations are different from the starting PNP equations, which contain no cross-diffusion terms, even for rather dilute binary electrolytes. At the same time, for infinitely dilute solutions the renormalized electric conductivity and renormalized diffusion coefficients are consistent and the classical PNP equations with renormalized coefficients are recovered, demonstrating the self-consistency of the fluctuating hydrodynamics equations. Our calculations show that the fluctuating hydrodynamics approach recovers the electrophoretic and relaxation corrections obtained by Debye–Huckel–Onsager theory, while elucidating the physical origins of these corrections and generalizing straightforwardly to more complex multispecies electrolytes. Lastly, we show that strong applied electric fields result in anisotropically enhanced “giant” velocity fluctuations and reduced fluctuations of salt concentration.« less

Fluctuation-enhanced electric conductivity in electrolyte solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Péraud, Jean-Philippe; Nonaka, Andrew J.; Bell, John B.

In this work, we analyze the effects of an externally applied electric field on thermal fluctuations for a binary electrolyte fluid. We show that the fluctuating Poisson–Nernst–Planck (PNP) equations for charged multispecies diffusion coupled with the fluctuating fluid momentum equation result in enhanced charge transport via a mechanism distinct from the well-known enhancement of mass transport that accompanies giant fluctuations. Although the mass and charge transport occurs by advection by thermal velocity fluctuations, it can macroscopically be represented as electrodiffusion with renormalized electric conductivity and a nonzero cation–anion diffusion coefficient. Specifically, we predict a nonzero cation–anion Maxwell– Stefan coefficient proportionalmore » to the square root of the salt concentration, a prediction that agrees quantitatively with experimental measurements. The renormalized or effective macroscopic equations are different from the starting PNP equations, which contain no cross-diffusion terms, even for rather dilute binary electrolytes. At the same time, for infinitely dilute solutions the renormalized electric conductivity and renormalized diffusion coefficients are consistent and the classical PNP equations with renormalized coefficients are recovered, demonstrating the self-consistency of the fluctuating hydrodynamics equations. Our calculations show that the fluctuating hydrodynamics approach recovers the electrophoretic and relaxation corrections obtained by Debye–Huckel–Onsager theory, while elucidating the physical origins of these corrections and generalizing straightforwardly to more complex multispecies electrolytes. Lastly, we show that strong applied electric fields result in anisotropically enhanced “giant” velocity fluctuations and reduced fluctuations of salt concentration.« less

Fluctuation-enhanced electric conductivity in electrolyte solutions.

PubMed

Péraud, Jean-Philippe; Nonaka, Andrew J; Bell, John B; Donev, Aleksandar; Garcia, Alejandro L

2017-10-10

We analyze the effects of an externally applied electric field on thermal fluctuations for a binary electrolyte fluid. We show that the fluctuating Poisson-Nernst-Planck (PNP) equations for charged multispecies diffusion coupled with the fluctuating fluid momentum equation result in enhanced charge transport via a mechanism distinct from the well-known enhancement of mass transport that accompanies giant fluctuations. Although the mass and charge transport occurs by advection by thermal velocity fluctuations, it can macroscopically be represented as electrodiffusion with renormalized electric conductivity and a nonzero cation-anion diffusion coefficient. Specifically, we predict a nonzero cation-anion Maxwell-Stefan coefficient proportional to the square root of the salt concentration, a prediction that agrees quantitatively with experimental measurements. The renormalized or effective macroscopic equations are different from the starting PNP equations, which contain no cross-diffusion terms, even for rather dilute binary electrolytes. At the same time, for infinitely dilute solutions the renormalized electric conductivity and renormalized diffusion coefficients are consistent and the classical PNP equations with renormalized coefficients are recovered, demonstrating the self-consistency of the fluctuating hydrodynamics equations. Our calculations show that the fluctuating hydrodynamics approach recovers the electrophoretic and relaxation corrections obtained by Debye-Huckel-Onsager theory, while elucidating the physical origins of these corrections and generalizing straightforwardly to more complex multispecies electrolytes. Finally, we show that strong applied electric fields result in anisotropically enhanced "giant" velocity fluctuations and reduced fluctuations of salt concentration.

Fluctuation-enhanced electric conductivity in electrolyte solutions

PubMed Central

Péraud, Jean-Philippe; Nonaka, Andrew J.; Bell, John B.; Donev, Aleksandar; Garcia, Alejandro L.

2017-01-01

We analyze the effects of an externally applied electric field on thermal fluctuations for a binary electrolyte fluid. We show that the fluctuating Poisson–Nernst–Planck (PNP) equations for charged multispecies diffusion coupled with the fluctuating fluid momentum equation result in enhanced charge transport via a mechanism distinct from the well-known enhancement of mass transport that accompanies giant fluctuations. Although the mass and charge transport occurs by advection by thermal velocity fluctuations, it can macroscopically be represented as electrodiffusion with renormalized electric conductivity and a nonzero cation–anion diffusion coefficient. Specifically, we predict a nonzero cation–anion Maxwell–Stefan coefficient proportional to the square root of the salt concentration, a prediction that agrees quantitatively with experimental measurements. The renormalized or effective macroscopic equations are different from the starting PNP equations, which contain no cross-diffusion terms, even for rather dilute binary electrolytes. At the same time, for infinitely dilute solutions the renormalized electric conductivity and renormalized diffusion coefficients are consistent and the classical PNP equations with renormalized coefficients are recovered, demonstrating the self-consistency of the fluctuating hydrodynamics equations. Our calculations show that the fluctuating hydrodynamics approach recovers the electrophoretic and relaxation corrections obtained by Debye–Huckel–Onsager theory, while elucidating the physical origins of these corrections and generalizing straightforwardly to more complex multispecies electrolytes. Finally, we show that strong applied electric fields result in anisotropically enhanced “giant” velocity fluctuations and reduced fluctuations of salt concentration. PMID:28973890

A prospective randomized trial of two solutions for intrapartum amnioinfusion: effects on fetal electrolytes, osmolality, and acid-base status.

PubMed

Pressman, E K; Blakemore, K J

1996-10-01

Our purpose was to compare the effects of intrapartum amnioinfusion with normal saline solution versus lactated Ringer's solution plus physiologic glucose on neonatal electrolytes and acid-base balance. Patients undergoing amnioinfusion for obstetric indications were randomized to receive normal saline solution or lactated Ringer's solution plus physiologic glucose at standardized amnioinfusion rates. Data were collected prospectively on maternal demographics, course of labor, and maternal and neonatal outcome. Arterial cord blood was obtained for analysis of electrolytes, glucose, osmolality, lactic acid, and blood gases. Control subjects with normal fetal heart rate patterns, and clear amniotic fluid not receiving amnioinfusion were studied concurrently. Data were collected on 59 patients (21 normal saline solution, 18 lactated Ringer's solution plus physiologic glucose, and 20 controls). Maternal demographics, course of labor, and neonatal outcome were similar in all three groups. Cesarean sections were performed more often in the amnioinfusion groups (33.3% for normal saline solution, 38.9% for lactated Ringer's solution plus physiologic glucose) than in the control group (5.0%), p < 0.05. Cord arterial electrolytes, glucose, osmolality, lactic acid, and blood gases were not altered by amnioinfusion with either solution. Intrapartum amnioinfusion with normal saline solution or lactated Ringer's solution plus physiologic glucose has no effect on neonatal electrolytes or acid-base balance.

Unusual effect of the magnetic field component of the microwave radiation on aqueous electrolyte solutions.

PubMed

Horikoshi, Satoshi; Sumi, Takuya; Serpone, Nick

2012-01-01

The heating characteristics of aqueous electrolyte solutions (NaCl, KCl, CaCl2, NaBF4, and NaBr) of varying concentrations in ultrapure water by 2.45 GHz microwave radiation from a single-mode resonance microwave device and a semiconductor microwave generator were examined under conditions where the electric field (E-field) was dominant and where the magnetic field (H-field) dominated. Although magnetic field heating is not generally used in microwave chemistry, the electrolyte solutions were heated almost entirely by the microwaves' H-field. The heating rates under H-field irradiation at the higher concentrations of electrolytes (0.125 M to 0.50 M) exceeded the rates under E-field irradiation. This inversion phenomenon in heating is described in terms of the penetration depth of the microwaves. On the other hand, the action of the microwave radiation on ethylene glycol containing an electrolyte differed from that observed for water under E-field and H-field conditions.

ELECTROLYTIC SOLUTIONS. Annual Progress Report, May 1, 1962-June 1, 1963

DOE Office of Scientific and Technical Information (OSTI.GOV)

Braunstein, J.

Results of investigations of the thermodynamics of association in molten salts and in concentrated aqueous electrolyte solutions are reported. Association constants of Pb(II) with chloride or bromide and of Cd(II) with chloride or bromide in molten mixtures of LiNC/sub 3/ and KNO/sub 3/ were measured potentiometrically at several temperatures and compared with previous results in mixtures of NaNO/sub 3/ and KNO/sub 3/. The anomalous'' solvent effect of lithium ion, reported previously for the association of Cd(II) with bromide was observed aiso for the other associations and a tentative explanation is suggested. The temperature dependence of the association constants was foundmore » to be in agreement with the quasi-lattice model. The association constant of Ag(I) with iodide in molten mixtures of NaNO/sub 3/ and KNO/sub 3/ was measured and compared with previous results in pure KNO/sub 3/. The solvent effect was consistent with the reciprocal coulomb effect.'' Techniques were developed, and preliminary results obtained for measuring association constants in the solvent system KNO/sub 3/--Ca(NO/sub 3/)/sub 2/ in order to investigate the effect of charge as well as size of solvent cation on association constants in molten salt solutions. The measurement of association constants in concentrated aqueous electrolyte solutions was continued. The association of Cd(II) with bromide in aqueous LiNC/sub 3/ was measured as part of a program to find a system that would lend itself to investigation over the range between anhydrous molten salt and aqueous electrolyte solution. Cells and electrodes were developed for investigating association constants in equimolar LiNO/sub 3/ -KNO/sub 3/ with controlled small water contents, and preliminary results are reported. (auth)« less

Excited state intramolecular charge transfer reaction in nonaqueous electrolyte solutions: Temperature dependence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pradhan, Tuhin; Gazi, Harun Al Rasid; Biswas, Ranjit

2009-08-07

Temperature dependence of the excited state intramolecular charge transfer reaction of 4-(1-azetidinyl)benzonitrile (P4C) in ethyl acetate (EA), acetonitrile (ACN), and ethanol at several concentrations of lithium perchlorate (LiClO{sub 4}) has been investigated by using the steady state and time resolved fluorescence spectroscopic techniques. The temperature range considered is 267-343 K. The temperature dependent spectral peak shifts and reaction driving force (-{Delta}G{sub r}) in electrolyte solutions of these solvents can be explained qualitatively in terms of interaction between the reactant molecule and ion-atmosphere. Time resolved studies indicate that the decay kinetics of P4C is biexponential, regardless of solvents, LiClO{sub 4} concentrations,more » and temperatures considered. Except at higher electrolyte concentrations in EA, reaction rates in solutions follow the Arrhenius-type temperature dependence where the estimated activation energy exhibits substantial electrolyte concentration dependence. The average of the experimentally measured activation energies in these three neat solvents is found to be in very good agreement with the predicted value based on data in room temperature solvents. While the rate constant in EA shows a electrolyte concentration induced parabolic dependence on reaction driving force (-{Delta}G{sub r}), the former in ethanol and ACN increases only linearly with the increase in driving force (-{Delta}G{sub r}). The data presented here also indicate that the step-wise increase in solvent reorganization energy via sequential addition of electrolyte induces the ICT reaction in weakly polar solvents to crossover from the Marcus inverted region to the normal region.« less

Theoretical study on the sound absorption of electrolytic solutions. I. Theoretical formulation.

PubMed

Yamaguchi, T; Matsuoka, T; Koda, S

2007-04-14

A theory is formulated that describes the sound absorption of electrolytic solutions due to the relative motion of ions, including the formation of ion pairs. The theory is based on the Kubo-Green formula for the bulk viscosity. The time correlation function of the pressure is projected onto the bilinear product of the density modes of ions. The time development of the product of density modes is described by the diffusive limit of the generalized Langevin equation, and approximate expressions for the three- and four-body correlation functions required are given with the hypernetted-chain integral equation theory. Calculations on the aqueous solutions of model electrolytes are performed. It is demonstrated that the theory describes both the activated barrier crossing between contact and solvent-separated ion pairs and the Coulombic correlation between ions.

Theoretical study on the sound absorption of electrolytic solutions. I. Theoretical formulation

NASA Astrophysics Data System (ADS)

Yamaguchi, T.; Matsuoka, T.; Koda, S.

2007-04-01

A theory is formulated that describes the sound absorption of electrolytic solutions due to the relative motion of ions, including the formation of ion pairs. The theory is based on the Kubo-Green formula for the bulk viscosity. The time correlation function of the pressure is projected onto the bilinear product of the density modes of ions. The time development of the product of density modes is described by the diffusive limit of the generalized Langevin equation, and approximate expressions for the three- and four-body correlation functions required are given with the hypernetted-chain integral equation theory. Calculations on the aqueous solutions of model electrolytes are performed. It is demonstrated that the theory describes both the activated barrier crossing between contact and solvent-separated ion pairs and the Coulombic correlation between ions.

Effect of Concentration on the Electrochemistry and Speciation of the Magnesium Aluminum Chloride Complex Electrolyte Solution.

PubMed

See, Kimberly A; Liu, Yao-Min; Ha, Yeyoung; Barile, Christopher J; Gewirth, Andrew A

2017-10-18

Magnesium batteries offer an opportunity to use naturally abundant Mg and achieve large volumetric capacities reaching over four times that of conventional Li-based intercalation anodes. High volumetric capacity is enabled by the use of a Mg metal anode in which charge is stored via electrodeposition and stripping processes, however, electrolytes that support efficient Mg electrodeposition and stripping are few and are often prepared from highly reactive compounds. One interesting electrolyte solution that supports Mg deposition and stripping without the use of highly reactive reagents is the magnesium aluminum chloride complex (MACC) electrolyte. The MACC exhibits high Coulombic efficiencies and low deposition overpotentials following an electrolytic conditioning protocol that stabilizes species necessary for such behavior. Here, we discuss the effect of the MgCl 2 and AlCl 3 concentrations on the deposition overpotential, current density, and the conditioning process. Higher concentrations of MACC exhibit enhanced Mg electrodeposition current density and much faster conditioning. An increase in the salt concentrations causes a shift in the complex equilibria involving both cations. The conditioning process is strongly dependent on the concentration suggesting that the electrolyte is activated through a change in speciation of electrolyte complexes and is not simply due to the annihilation of electrolyte impurities. Additionally, the presence of the [Mg 2 (μ-Cl) 3 ·6THF] + in the electrolyte solution is again confirmed through careful analysis of experimental Raman spectra coupled with simulation and direct observation of the complex in sonic spray ionization mass spectrometry. Importantly, we suggest that the ∼210 cm -1 mode commonly observed in the Raman spectra of many Mg electrolytes is indicative of the C 3v symmetric [Mg 2 (μ-Cl) 3 ·6THF] + . The 210 cm -1 mode is present in many electrolytes containing MgCl 2 , so its assignment is of broad interest

Dynamic mechanism of equivalent conductivity minimum of electrolyte solution

NASA Astrophysics Data System (ADS)

Yamaguchi, T.; Matsuoka, T.; Koda, S.

2011-10-01

The theory on electric conductivity of electrolyte solutions we have developed [T. Yamaguchi, T. Matsuoka, and S. Koda, J. Chem. Phys. 127, 064508 (2007)] is applied to a model electrolyte solution that shows a minimum of equivalent conductivity as the function of concentration [T. Yamaguchi, T. Akatsuka, and S. Koda, J. Chem. Phys. 134, 244506 (2011)]. The theory succeeds in reproducing the equivalent conductivity minimum, whereas the mode-coupling theory (MCT) underestimates the conductivity in the low-concentration regime. The theory can also reproduce the decrease in the relaxation time of conductivity with increasing the concentration we have demonstrated with a Brownian dynamics simulation. A detailed analysis shows that the relaxation of the conductivity occurs through two processes. The faster one corresponds to the collision between a cation and an anion, and the slower one does to the polarization of the ionic atmosphere. The increase in the equivalent conductivity with concentration is attributed to the decrease in the effect of the ionic atmosphere, which is in turn explained by the fact that the counter ion cannot penetrate into the repulsive core when the Debye screening length is compatible or smaller than the ionic diameter. The same mechanism is also observed in MCT calculation with static structure factor determined by mean-spherical approximation.

On the Oxidation State of Manganese Ions in Li-Ion Battery Electrolyte Solutions.

PubMed

Banerjee, Anjan; Shilina, Yuliya; Ziv, Baruch; Ziegelbauer, Joseph M; Luski, Shalom; Aurbach, Doron; Halalay, Ion C

2017-02-08

We demonstrate herein that Mn 3+ and not Mn 2+ , as commonly accepted, is the dominant dissolved manganese cation in LiPF 6 -based electrolyte solutions of Li-ion batteries with lithium manganate spinel positive and graphite negative electrodes chemistry. The Mn 3+ fractions in solution, derived from a combined analysis of electron paramagnetic resonance and inductively coupled plasma spectroscopy data, are ∼80% for either fully discharged (3.0 V hold) or fully charged (4.2 V hold) cells, and ∼60% for galvanostatically cycled cells. These findings agree with the average oxidation state of dissolved Mn ions determined from X-ray absorption near-edge spectroscopy data, as verified through a speciation diagram analysis. We also show that the fractions of Mn 3+ in the aprotic nonaqueous electrolyte solution are constant over the duration of our experiments and that disproportionation of Mn 3+ occurs at a very slow rate.

Anomalously enhanced hydration of aqueous electrolyte solution in hydrophobic carbon nanotubes to maintain stability.

PubMed

Ohba, Tomonori

2014-02-24

An understanding of the structure and behavior of electrolyte solutions in nanoenvironements is crucial not only for a wide variety of applications, but also for the development of physical, chemical, and biological processes. We demonstrate the structure and stability of electrolyte in carbon nanotubes using hybrid reverse Monte Carlo simulations of X-ray diffraction patterns. Hydrogen bonds between water are adequately formed in carbon nanotubes, although some hydrogen bonds are restricted by the interfaces of carbon nanotubes. The hydrogen bonding network of water in electrolyte in the carbon nanotubes is further weakened. On the other hand, formation of the ion hydration shell is significantly enhanced in the electrolyte in the carbon nanotubes in comparison to ion hydration in bulk electrolyte. The significant hydrogen bond and hydration shell formation are a result of gaining stability in the hydrophobic nanoenvironment. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

X-ray Raman spectroscopy of lithium-ion battery electrolyte solutions in a flow cell.

PubMed

Ketenoglu, Didem; Spiekermann, Georg; Harder, Manuel; Oz, Erdinc; Koz, Cevriye; Yagci, Mehmet C; Yilmaz, Eda; Yin, Zhong; Sahle, Christoph J; Detlefs, Blanka; Yavaş, Hasan

2018-03-01

The effects of varying LiPF 6 salt concentration and the presence of lithium bis(oxalate)borate additive on the electronic structure of commonly used lithium-ion battery electrolyte solvents (ethylene carbonate-dimethyl carbonate and propylene carbonate) have been investigated. X-ray Raman scattering spectroscopy (a non-resonant inelastic X-ray scattering method) was utilized together with a closed-circle flow cell. Carbon and oxygen K-edges provide characteristic information on the electronic structure of the electrolyte solutions, which are sensitive to local chemistry. Higher Li + ion concentration in the solvent manifests itself as a blue-shift of both the π* feature in the carbon edge and the carbonyl π* feature in the oxygen edge. While these oxygen K-edge results agree with previous soft X-ray absorption studies on LiBF 4 salt concentration in propylene carbonate, carbon K-edge spectra reveal a shift in energy, which can be explained with differing ionic conductivities of the electrolyte solutions.

A Modified Robinson-Stokes equation for describing the thermodynamic properties of aqueous solutions of 1-1 electrolytes

NASA Astrophysics Data System (ADS)

Rudakov, A. M.; Sergievskii, V. V.

2008-05-01

Equations relating osmotic, mean ionic activity, and water activity coefficients to electrolyte concentrations in binary aqueous solutions were substantiated within the framework of cluster concepts. The model includes the contribution to solution nonideality of electrostatic interactions in terms of the Debye-Hückel theory along with hydration and association of salts via relations containing hydration and association numbers in the standard states. According to the description of data on 54 aqueous solutions of 1-1 electrolytes, this model should be given preference compared with the most extensively used NRTL, NRTL-NRF, Wilson, and Pitzer models.

Effects of the background electrolyte on Th(IV) sorption to muscovite mica

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmidt, Moritz; Hellebrandt, Stefan; Knope, Karah E.

2015-09-01

The adsorption of tetravalent thorium on the muscovite mica (001) basal plane was studied by X-ray crystal truncation rod (CTR), and resonant anomalous X-ray reflectivity (RAXR) measurements and alpha spectrometry in the presence of perchlorate background electrolytes LiClO 4, NaClO 4, and KClO 4 ([Th(IV)] = 0.1 mM, I = 0.1 M or 0.01 M, pH = 3.3 ± 0.3). RAXR data directly reveal a strong influence of the background electrolyte on the actinide sorption. No significant Th adsorption was observed in 0.1 M NaClO 4, i.e., the Th coverage θ(Th), the number of Th per unit cell area ofmore » the muscovite surface (A UC = 46.72 Å 2), was ≤ 0.01 Th/A UC, whereas limited uptake (θ(Th) ~ 0.04 Th/A UC) was detected at a lower ionic strength (I = 0.01 M). These results are in stark contrast to the behavior of Th in 0.1 M NaCl which showed a coverage of 0.4 Th/A UC (Schmidt et al., 2012a). Th uptake was also influenced by the electrolyte cation. Weak adsorption was observed in 0.1M KClO 4 (θ(Th) ~ 0.07 Th/AUC) similar to the results in NaClO 4 at lower ionic strength. In contrast, strong adsorption was found in 0.1 M LiClO 4, with θ(Th) = 4.9 Th/A UC, a ~10-fold increase compared with that previously reported in NaCl. These differences are confirmed independently by ex situ alpha spectrometry, which shows no measurable Th coverage in 0.1 M NaClO 4 background in contrast to a large coverage of 1.6 Th/A UC in 0.1 M LiClO 4. The CTR/RAXR analyses of Th-LiClO 4 show the sorption structure consisting of Th species that are broadly distributed, centered at heights of 4.1 Å and 29 Å distance from the interface. Neither the very large distribution height of the second species nor the high coverage can be explained with (hydrated) ionic adsorption, suggesting that the enhanced uptake is presumably due to the formation and sorption of Th nanoparticles.« less

A lithium ion battery using an aqueous electrolyte solution

PubMed Central

Chang, Zheng; Li, Chunyang; Wang, Yanfang; Chen, Bingwei; Fu, Lijun; Zhu, Yusong; Zhang, Lixin; Wu, Yuping; Huang, Wei

2016-01-01

Energy and environmental pollution have become the two major problems in today’s society. The development of green energy storage devices with good safety, high reliability, high energy density and low cost are urgently demanded. Here we report on a lithium ion battery using an aqueous electrolyte solution. It is built up by using graphite coated with gel polymer membrane and LISICON as the negative electrode, and LiFePO4 in aqueous solution as the positive electrode. Its average discharge voltage is up to 3.1 V and energy density based on the two electrode materials is 258 Wh kg−1. It will be a promising energy storage system with good safety and efficient cooling effects. PMID:27328707

Compatibility of electrolytically produced sodium hypochlorite solutions on long- term implanted dialysis catheters.

PubMed

Mishkin, G J

2007-01-01

More than 20% of the world's population use a catheter for dialysis, despite guidelines limiting their use. Although the structure and design of the catheters differ by manufacturer, the material used in central venous catheters and peritoneal dialysis catheters are the same across manufacturers. Given the long-term use of these catheters in the dialysis population, the good compatibility of the antiseptics and disinfectants used on the catheters is imperative to prevent failure and cracking of the catheter material. Tensile strengths of commercially available catheters were measured after exposure to commonly used disinfectants. The tensile strength was then compared between the catheters by analyzing the displacement vs. force (N) curves produced during the evaluation. A total of 44 catheter lumens were evaluated. The electrolytically produced sodium hypochlorite solution, Alcavis 50/ExSept Plus, was the only solution shown to be compatible with all three catheter materials resulting in a deviation of less than 10% for each of the different catheter types. Electrolytically produced sodium hypochlorite solutions were the only solutions in this study that did not alter the physical properties of any of the catheters after long-term exposure.

Separation of electrolyte solutions by reverse osmosis.

PubMed

Starov, V M; Churaev, N V

1993-05-09

The paper presented is subdivided into two parts. The first one includes a survey of current notions concerning the physico-chemical nature of interaction potential phi between dissolved molecules or ions and water with a membrane material. Special attention is paid to the structural potential and the potential of image forces. The main conclusion is that the potential of interaction phi determines the major part of phenomena which are relevant for reverse osmosis (RO) separation. In the second part the distribution coefficient gamma = exp (phi) is supposed to be known and a survey of theoretical investigations of RO processes is undertaken. The so called homogeneous model of RO membranes is employed and concentration polarization is taken into account. Two main points in this investigation should be emphasized, that is, taking into account concentration polarization and a theory of RO separation of electrolyte mixtures. The maximum value of rejection coefficient and corresponding optimum velocity of filtration are calculated. Negative rejection of some ions from the mixture is explained, as well as a change in pH of filtrate. The streaming potential is calculated as a function of Peclet number, distribution coefficients, membrane charge and so on in all cases. The suggested theory gives the possibility to explain a number of phenomena in RO separation of electrolyte solutions.

Water and solute absorption from carbohydrate-electrolyte solutions in the human proximal small intestine: a review and statistical analysis.

PubMed

Shi, Xiaocai; Passe, Dennis H

2010-10-01

The purpose of this study is to summarize water, carbohydrate (CHO), and electrolyte absorption from carbohydrate-electrolyte (CHO-E) solutions based on all of the triple-lumen-perfusion studies in humans since the early 1960s. The current statistical analysis included 30 reports from which were obtained information on water absorption, CHO absorption, total solute absorption, CHO concentration, CHO type, osmolality, sodium concentration, and sodium absorption in the different gut segments during exercise and at rest. Mean differences were assessed using independent-samples t tests. Exploratory multiple-regression analyses were conducted to create prediction models for intestinal water absorption. The factors influencing water and solute absorption are carefully evaluated and extensively discussed. The authors suggest that in the human proximal small intestine, water absorption is related to both total solute and CHO absorption; osmolality exerts various impacts on water absorption in the different segments; the multiple types of CHO in the ingested CHO-E solutions play a critical role in stimulating CHO, sodium, total solute, and water absorption; CHO concentration is negatively related to water absorption; and exercise may result in greater water absorption than rest. A potential regression model for predicting water absorption is also proposed for future research and practical application. In conclusion, water absorption in the human small intestine is influenced by osmolality, solute absorption, and the anatomical structures of gut segments. Multiple types of CHO in a CHO-E solution facilitate water absorption by stimulating CHO and solute absorption and lowering osmolality in the intestinal lumen.

Implementation of equilibrium aqueous speciation and solubility (EQ3 type) calculations into Cantera for electrolyte solutions.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moffat, Harry K.; Jove-Colon, Carlos F.

2009-06-01

In this report, we summarize our work on developing a production level capability for modeling brine thermodynamic properties using the open-source code Cantera. This implementation into Cantera allows for the application of chemical thermodynamics to describe the interactions between a solid and an electrolyte solution at chemical equilibrium. The formulations to evaluate the thermodynamic properties of electrolytes are based on Pitzer's model to calculate molality-based activity coefficients using a real equation-of-state (EoS) for water. In addition, the thermodynamic properties of solutes at elevated temperature and pressures are computed using the revised Helgeson-Kirkham-Flowers (HKF) EoS for ionic and neutral aqueous species.more » The thermodynamic data parameters for the Pitzer formulation and HKF EoS are from the thermodynamic database compilation developed for the Yucca Mountain Project (YMP) used with the computer code EQ3/6. We describe the adopted equations and their implementation within Cantera and also provide several validated examples relevant to the calculations of extensive properties of electrolyte solutions.« less

THE CONTRIBUTIONS OF NORMAL AND ANOMALOUS OSMOSIS TO THE OSMOTIC EFFECTS ARISING ACROSS CHARGED MEMBRANES WITH SOLUTIONS OF ELECTROLYTES

PubMed Central

Grim, Eugene; Sollner, Karl

1957-01-01

The osmotic effect arising across a porous membrane separating the solution of an electrolyte from water (or a more dilute solution) is ordinarily due to both normal osmosis, as it occurs also with non-electrolytes, and to "anomalous" osmosis. It is shown that the normal osmotic component cannot be measured quantitatively by the conventional comparison with a non-electrolytic reference solute. Anomalous osmosis does not occur with electroneutral membranes. Accordingly, with membranes which can be charged and discharged reversibly (without changes in geometrical structure), such as many proteinized membranes, the osmotic effects caused by an electrolyte can be measured both when only normal osmosis arises (with the membrane in the electroneutral state) and when normal as well as anomalous osmosis occurs (with the membrane in a charged state). The difference between these two effects is the true anomalous osmosis. Data are presented on the osmotic effects across an oxyhemoglobin membrane in the uncharged state at pH 6.75 and in two charged states, positive at pH 4.0 and negative at pH 10.0, with solutions of a variety of electrolytes using a concentration ratio of 2:1 over a wide range of concentrations. The rates of the movement of liquid across the membrane against an inconsequentially small hydrostatic head are recorded instead of, as conventional, the physiologically less significant pressure rises after a standard time. PMID:13439166

Internal electric fields of electrolytic solutions induced by space-charge polarization

NASA Astrophysics Data System (ADS)

Sawada, Atsushi

2006-10-01

The dielectric dispersion of electrolytic solutions prepared using chlorobenzene as a solvent and tetrabutylammonium tetraphenylborate as a solute is analyzed in terms of space-charge polarization in order to derive the ionic constants, and the Stokes radius obtained is discussed in comparison with the values that have been measured by conductometry. A homogeneous internal electric field is assumed for simplicity in the analysis of the space-charge polarization. The justification of the approximation by the homogeneous field is discussed from two points of view: one is the accuracy of the Stokes radius value observed and the other is the effect of bound charges on electrodes in which they level the highly inhomogeneous field, which has been believed in the past. In order to investigate the actual electric field, numerical calculations based on the Poisson equation are carried out by considering the influence of the bound charges. The variation of the number of bound charges with time is clarified by determining the relaxation function of the dielectric constant attributed to the space-charge polarization. Finally, a technique based on a two-field approximation, where homogeneous and hyperbolic fields are independently applied in relevant frequency ranges, is introduced to analyze the space-charge polarization of the electrolytic solutions, and further improvement of the accuracy in the determination of the Stokes radius is achieved.

Characterization of stainless steel surface processed using electrolytic oxidation and titanium complex ion solution

NASA Astrophysics Data System (ADS)

Kang, Yubin; Choi, Jaeyoung; Park, Jinju; Kim, Woo-Byoung; Lee, Kun-Jae

2017-09-01

This study attempts to improve the physical and chemical adhesion between metals and ceramics by using electrolytic oxidation and a titanium organic/inorganic complex ion solution on the SS-304 plate. Surface analysis confirmed the existence of the Tisbnd Osbnd Mx bonds formed by the bonding between the metal ions and the Ti oxide at the surface of the pre-processed SS plate, and improved chemical adhesion during ceramic coating was expected by confirming the presence of the carboxylic group. The adhesion was evaluated by using the ceramic coating solution in order to assess the improved adhesion of the SS plate under conditions. The results showed that both the adhesion and durability were largely improved in the sample processed with all the pre-processing steps, thus confirming that the physical and chemical adhesion between metals and ceramics can be improved by enhancing the physical roughness via electrolytic oxidation and pre-processing using a Ti complex ion solution.

The influence of electrolyte additives on the anodic dissolution of aluminum in alkaline solutions

NASA Astrophysics Data System (ADS)

Boehnstedt, W.

1980-09-01

The paper describes the effect of electrolyte additives on the anodic dissolution of aluminum in alkaline solutions. The dissolution is accelerated by the addition of small quantities of gallium or indium ions to the electrolyte indicated by the shift of the zero current potential by about 250 mV on the current-potential curve. Scanning electron microscope studies showed that gallium ions produce many small cracks in the aluminum electrode and collect at the grain boundary areas, increasing the electrode surface; this enlargement, in combination with increased electrolyte agitation due to greater hydrogen evolution, provides higher current densities at the same potential. It is concluded that this process will widen the possibilities of using aluminum and its alloys in high-rate batteries.

Electrochemical performance of solid oxide fuel cells having electrolytes made by suspension and solution precursor plasma spraying

NASA Astrophysics Data System (ADS)

Marr, M.; Kuhn, J.; Metcalfe, C.; Harris, J.; Kesler, O.

2014-01-01

Yttria-stabilized zirconia (YSZ) electrolytes were deposited by suspension plasma spraying (SPS) and solution precursor plasma spraying (SPPS). The electrolytes were evaluated for permeability, microstructure, and electrochemical performance. With SPS, three different suspensions were tested to explore the influence of powder size distribution and liquid properties. Electrolytes made from suspensions of a powder with d50 = 2.6 μm were more gas-tight than those made from suspensions of a powder with d50 = 0.6 μm. A peak open circuit voltage of 1.00 V was measured at 750 °C with a cell with an electrolyte made from a suspension of d50 = 2.6 μm powder. The use of a flammable suspension liquid was beneficial for improving electrolyte conductivity when using lower energy plasmas, but the choice of liquid was less important when using higher energy plasmas. With SPPS, peak electrolyte conductivities were comparable to the peak conductivities of the SPS electrolytes. However, leak rates through the SPPS electrolytes were higher than those through the electrolytes made from suspensions of d50 = 2.6 μm powder. The electrochemical test data on SPPS electrolytes are the first reported in the literature.

Electrostatics of polymer translocation events in electrolyte solutions.

PubMed

Buyukdagli, Sahin; Ala-Nissila, T

2016-07-07

We develop an analytical theory that accounts for the image and surface charge interactions between a charged dielectric membrane and a DNA molecule translocating through the membrane. Translocation events through neutral carbon-based membranes are driven by a competition between the repulsive DNA-image-charge interactions and the attractive coupling between the DNA segments on the trans and the cis sides of the membrane. The latter effect is induced by the reduction of the coupling by the dielectric membrane. In strong salt solutions where the repulsive image-charge effects dominate the attractive trans-cis coupling, the DNA molecule encounters a translocation barrier of ≈10 kBT. In dilute electrolytes, the trans-cis coupling takes over image-charge forces and the membrane becomes a metastable attraction point that can trap translocating polymers over long time intervals. This mechanism can be used in translocation experiments in order to control DNA motion by tuning the salt concentration of the solution.

Electrolytic method to make alkali alcoholates using ion conducting alkali electrolyte/separator

DOEpatents

Joshi, Ashok V [Salt Lake City, UT; Balagopal, Shekar [Sandy, UT; Pendelton, Justin [Salt Lake City, UT

2011-12-13

Alkali alcoholates, also called alkali alkoxides, are produced from alkali metal salt solutions and alcohol using a three-compartment electrolytic cell. The electrolytic cell includes an anolyte compartment configured with an anode, a buffer compartment, and a catholyte compartment configured with a cathode. An alkali ion conducting solid electrolyte configured to selectively transport alkali ions is positioned between the anolyte compartment and the buffer compartment. An alkali ion permeable separator is positioned between the buffer compartment and the catholyte compartment. The catholyte solution may include an alkali alcoholate and alcohol. The anolyte solution may include at least one alkali salt. The buffer compartment solution may include a soluble alkali salt and an alkali alcoholate in alcohol.

Electrolytic dissolver

DOEpatents

Wheelwright, E.J.; Fox, R.D.

1975-08-26

This patent related to an electrolytic dissolver wherein dissolution occurs by solution contact including a vessel of electrically insulative material, a fixed first electrode, a movable second electrode, means for insulating the electrodes from the material to be dissolved while permitting a free flow of electrolyte therebetween, means for passing a direct current between the electrodes and means for circulating electrolyte through the dissolver. (auth)

Thermal and electrochemical properties of nonflammable electrolyte solutions containing fluorinated alkylphosphates for lithium-ion batteries

NASA Astrophysics Data System (ADS)

Todorov, Yanko Marinov; Aoki, Masahiro; Mimura, Hideyuki; Fujii, Kenta; Yoshimoto, Nobuko; Morita, Masayuki

2016-11-01

Nonflammable organic electrolyte solutions containing fluorinated alkylphosphates (FAP) have been examined as safer electrolytes for lithium-ion batteries (LIB). Although the ionic conductivity of LiPF6 in neat tris(2,2,2-trifluoroethyl)phosphate (TFEP) solvent is very low, it increases upon the addition of alkyl carbonates such as ethylene carbonate (EC) and fluoroethylene carbonate (4-fluoro-2-oxo-1,3-dioxolane, FEC). A specific conductivity of 1 mS cm-1 or higher was obtained at room temperature for the system containing proper amounts of the carbonates and 0.5 M (mol dm-3) LiPF6. A conventional mixed alkylcarbonate-based solution containing LiPF6 showed a sign of considerable exothermic reactions on the differential scanning calorimetry (DSC) response below 300 °C. However, the LiPF6/TFEP solution showed no significant exothermic response up to 400 °C, even in the presence of charged LiCoO2 (LCO) positive electrode. The addition of an alkylcarbonate to the LiPF6/TFEP solution produced an exothermic response as a result of the thermal decomposition of the carbonate over the charged LCO. However, the temperature at which the exothermic reaction starts was significantly higher in the system containing FEC than that containing EC. The thermal analysis results suggested that the LiPF6/FEC + TFEP combination could work as a safer electrolyte system in LIB under severe conditions.

[Adverse effects of drugs in intensive care units: analysis of the administration of electrolyte solutions and antibiotics].

PubMed

Manenti, S; Chaves, A B; Leopoldino, R S; Padilha, K G

1998-12-01

The aims of this study were: 1) to verify the incidence of adverse occurrences (AOs) with medication related to the time of electrolyte solutions infusion and the frequency of doses of antibiotics prescribed and administered to the patients; 2) to characterize the nature of those occurrences. The study was developed in two ICUs of a general hospital of São Paulo City. The population was composed by 51 patients that were in the ICUs in August of 1996. Sixty percent of the patients were older than 60 years, 58.8% were women, 49.1% remained in ICU from 1 to 4 days and 41.2% went to the Intermediate Care Units after ICU. Regarding the incidence of AOs related to the time of administration of the electrolyte solutions and the frequency of doses of antibiotics the non execution of the patient's medical prescriptions was verified in 76.3% and 38.8% respectively. The largest frequency of irregularities with the electrolyte solutions (60.2%) was the infusion faster than the prescribed time followed by the reduction of the number of doses of antibiotics administered. Taking these into consideration we have to invest in preventive measures to reduce those occurrences.

Bimodal dielectric relaxation of electrolyte solutions in weakly polar solvents.

PubMed

Yamaguchi, Tsuyoshi; Koda, Shinobu

2014-12-28

The dielectric relaxation spectra of dilute electrolyte solutions in solvents of small dielectric constants are investigated both theoretically and experimentally. The theoretical calculation in our previous work [T. Yamaguchi, T. Matsuoka, and S. Koda, J. Chem. Phys. 135, 164511 (2011)] is reanalyzed, and it is shown that the dielectric relaxation spectra are composed of three components, namely, the relaxation of ionic atmosphere, the reorientational relaxation of ion pairs, and the collision between ions. The relaxation frequency of the slowest one increases with increasing the concentration, and the slower two relaxations, those of ionic atmosphere and ion pairs, merge into one at the concentration where the Debye length is comparable to the size of ions. Experimentally, the dielectric relaxation spectra of some electrolytes in two solvents, tetrahydrofuran and tetraglyme, are determined at frequencies from 300 kHz to 200 MHz, and the presence of the slower two relaxations was confirmed. The concentration dependence of the relaxation frequency is also in harmony with the theoretical calculation. The relationship between the dielectric relaxation spectra and the concentration dependence of the ionic conductivity is discussed.

Bimodal dielectric relaxation of electrolyte solutions in weakly polar solvents

NASA Astrophysics Data System (ADS)

Yamaguchi, Tsuyoshi; Koda, Shinobu

2014-12-01

The dielectric relaxation spectra of dilute electrolyte solutions in solvents of small dielectric constants are investigated both theoretically and experimentally. The theoretical calculation in our previous work [T. Yamaguchi, T. Matsuoka, and S. Koda, J. Chem. Phys. 135, 164511 (2011)] is reanalyzed, and it is shown that the dielectric relaxation spectra are composed of three components, namely, the relaxation of ionic atmosphere, the reorientational relaxation of ion pairs, and the collision between ions. The relaxation frequency of the slowest one increases with increasing the concentration, and the slower two relaxations, those of ionic atmosphere and ion pairs, merge into one at the concentration where the Debye length is comparable to the size of ions. Experimentally, the dielectric relaxation spectra of some electrolytes in two solvents, tetrahydrofuran and tetraglyme, are determined at frequencies from 300 kHz to 200 MHz, and the presence of the slower two relaxations was confirmed. The concentration dependence of the relaxation frequency is also in harmony with the theoretical calculation. The relationship between the dielectric relaxation spectra and the concentration dependence of the ionic conductivity is discussed.

Stresses due to Relative Sliding between Particles Surrounded by an Electrolyte Solution with Application to Lithium-Ion Batteries

NASA Astrophysics Data System (ADS)

Zhang, Cong; Conlisk, A. T.

2013-11-01

Mechanical stresses in the solid phase of the electrodes within lithium-ion batteries have been the subject of much work recently with the emphasis on the stresses induced by lithium insertion to or extraction from the active solid material. The particles within lithium-ion battery electrodes can undergo relative motion with relative velocities of different magnitudes and directions. One mode of the relative motion, resembling the slider bearing motion, manifests itself as two particles sliding relative to each other within an electrolyte solution. The electrolyte solution within the narrow pores between the particles is the medium through which the particles interact with each other. The effect of the electrolyte solution is not conventionally considered. The relative motion of the particles induces significant pressures. The primary objective of this work is to develop a model based on the lubrication approximation to investigate the magnitude and direction of the stresses induced by this sliding motion. Other applications in the biomedical field are also discussed. Supported by DOE Graduate Automotive Technology Education (GATE) and OSU Center for Automotive Research.

Charge regulation at semiconductor-electrolyte interfaces.

PubMed

Fleharty, Mark E; van Swol, Frank; Petsev, Dimiter N

2015-07-01

The interface between a semiconductor material and an electrolyte solution has interesting and complex electrostatic properties. Its behavior will depend on the density of mobile charge carriers that are present in both phases as well as on the surface chemistry at the interface through local charge regulation. The latter is driven by chemical equilibria involving the immobile surface groups and the potential determining ions in the electrolyte solution. All these lead to an electrostatic potential distribution that propagate such that the electrolyte and the semiconductor are dependent on each other. Hence, any variation in the charge density in one phase will lead to a response in the other. This has significant implications on the physical properties of single semiconductor-electrolyte interfaces and on the electrostatic interactions between semiconductor particles suspended in electrolyte solutions. The present paper expands on our previous publication (Fleharty et al., 2014) and offers new results on the electrostatics of single semiconductor interfaces as well as on the interaction of charged semiconductor colloids suspended in electrolyte solution. Copyright © 2014 Elsevier Inc. All rights reserved.

Electrolyte diodes with weak acids and bases. I. Theory and an approximate analytical solution.

PubMed

Iván, Kristóf; Simon, Péter L; Wittmann, Mária; Noszticzius, Zoltán

2005-10-22

Until now acid-base diodes and transistors applied strong mineral acids and bases exclusively. In this work properties of electrolyte diodes with weak electrolytes are studied and compared with those of diodes with strong ones to show the advantages of weak acids and bases in these applications. The theoretical model is a one dimensional piece of gel containing fixed ionizable groups and connecting reservoirs of an acid and a base. The electric current flowing through the gel is measured as a function of the applied voltage. The steady-state current-voltage characteristic (CVC) of such a gel looks like that of a diode under these conditions. Results of our theoretical, numerical, and experimental investigations are reported in two parts. In this first, theoretical part governing equations necessary to calculate the steady-state CVC of a reverse-biased electrolyte diode are presented together with an approximate analytical solution of this reaction-diffusion-ionic migration problem. The applied approximations are quasielectroneutrality and quasiequilibrium. It is shown that the gel can be divided into an alkaline and an acidic zone separated by a middle weakly acidic region. As a further approximation it is assumed that the ionization of the fixed acidic groups is complete in the alkaline zone and that it is completely suppressed in the acidic one. The general solution given here describes the CVC and the potential and ionic concentration profiles of diodes applying either strong or weak electrolytes. It is proven that previous formulas valid for a strong acid-strong base diode can be regarded as a special case of the more general formulas presented here.

Antimicrobial effects of electrolytic products of sodium chloride--comparative evaluation with sodium hypochlorite solution and efficacy in handwashing.

PubMed

Hitomi, S; Baba, S; Yano, H; Morisawa, Y; Kimura, S

1998-11-01

We examined the in vitro bactericidal effects and efficacy on handwashing of water containing electrolytic products of sodium chloride (electrolytic water). The electrolytic water, whose pH and concentration of free residual chlorine were 6.7-6.9 and 20-22 ppm, respectively, showed equal reduction of both Staphylococcus aureus and Escherichia coli to dilution of commercially available sodium hypochlorite containing 60 ppm of free residual chlorine. This bactericidal effect was calculated to be due to hypochlorous acid, based on the pH and the amount of chlorine in solution. Handwashing with the electrolytic water reduced the numbers of S. aureus on hands by 1/10(2), while running water and 0.2% benzalkonium chloride with 80% ethanol gave a 1/10 and 1/10(5) reduction, respectively. We conclude that electrolytic water might be applicable for handwashing in place of running water.

Hydroxyl radical production in plasma electrolysis with KOH electrolyte solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saksono, Nelson; Febiyanti, Irine Ayu, E-mail: irine.ayu41@ui.ac.id; Utami, Nissa

2015-12-29

Plasma electrolysis is an effective technology for producing hydroxyl radical (•OH). This method can be used for waste degradation process. This study was conducted to obtain the influence of applied voltage, electrolyte concentration, and anode depth in the plasma electrolysis system for producing hydroxyl radical. The materials of anode and cathode, respectively, were made from tungsten and stainless steel. KOH solution was used as the solution. Determination of hydroxyl radical production was done by measuring H{sub 2}O{sub 2} amount formed in plasma system using an iodometric titration method, while the electrical energy consumed was obtained by measuring the electrical currentmore » throughout the process. The highest hydroxyl radical production was 3.51 mmol reached with 237 kJ energy consumption in the power supply voltage 600 V, 0.02 M KOH, and 0.5 cm depth of anode.« less

Treatment of neonatal calf diarrhea with an oral electrolyte solution supplemented with psyllium mucilloid.

PubMed

Cebra, M L; Garry, F B; Cebra, C K; Adams, R; McCann, J P; Fettman, M J

1998-01-01

Dairy calves under 14 days of age with naturally occurring, uncomplicated diarrhea were treated for 3 days with a hypertonic oral electrolyte solution with (n = 15) or without (n = 12) psyllium. Clinical response and clinical pathology data were compared between the 2 groups. Glucose absorption was evaluated on days 1 and 3 by measurement of plasma glucose and lactate and serum insulin concentrations for 4 hours after formula administration. On day 1, glucose, lactate, and insulin concentrations were lower in psyllium-fed calves than in control calves, with significant differences noted in glucose and lactate concentrations at several time points (P < 0.05). Plasma lactate concentrations were higher at several times in both treatment groups on day 3 than on day 1 (P < 0.05). Fecal consistency was markedly different in psyllium-fed calves as compared with control calves within 24 hours of psyllium supplementation. Fecal percent dry matter content was lower in psyllium-fed calves than in control calves at least once a day during supplementation and on day 3 compared with day 0 in the psyllium-fed calves (P < 0.05). There were no significant differences in clinical performance scores, hydration status, arterial blood gas, serum anion gap, electrolyte, or total CO2 concentrations. Addition of psyllium to an oral electrolyte solution resulted in immediate alterations in glucose absorption without impairing rehydration in diarrheic calves, but differences were transient and did not affect clinical outcome.

Conductivity enhancement of silver nanowire networks via simple electrolyte solution treatment and solvent washing.

PubMed

Gu, Jiahui; Wang, Xuelin; Chen, Hongtao; Yang, Shihua; Feng, Huanhuan; Ma, Xing; Ji, Hongjun; Wei, Jun; Li, Mingyu

2018-06-29

As a promising replacement material for indium tin oxide in flexible electronics, silver nanowires (AgNWs) usually need complicated post-treatment to reduce the high contact resistance across the intersections when used as transparent conductive films. In this work, a widely applicable nano-joining method for improving the overall conductivity of AgNW networks with different kinds of electrolyte solutions is presented. By treatment with an electrolyte solution with appropriate ionic strengths, the insulating surfactant layer (polyvinylpyrrolidone, PVP) on the AgNWs could be desorbed, and the AgNW network could be densified. The sheet resistance of the AgNW film on a glass slide is reduced by 60.9% (from 67.5 to 26.4 Ohm sq -1 ) with a transmittance of 92.5%. High-resolution transmission electron microscopy analysis indicates that atomic diffusion occurs at the intersection of two AgNWs. Thus, metallurgical bonding on the nanometer scale is achieved across the junctions of the AgNWs, leading to a significant enhancement in the conductivity of the AgNW network.

Conductivity enhancement of silver nanowire networks via simple electrolyte solution treatment and solvent washing

NASA Astrophysics Data System (ADS)

Gu, Jiahui; Wang, Xuelin; Chen, Hongtao; Yang, Shihua; Feng, Huanhuan; Ma, Xing; Ji, Hongjun; Wei, Jun; Li, Mingyu

2018-06-01

As a promising replacement material for indium tin oxide in flexible electronics, silver nanowires (AgNWs) usually need complicated post-treatment to reduce the high contact resistance across the intersections when used as transparent conductive films. In this work, a widely applicable nano-joining method for improving the overall conductivity of AgNW networks with different kinds of electrolyte solutions is presented. By treatment with an electrolyte solution with appropriate ionic strengths, the insulating surfactant layer (polyvinylpyrrolidone, PVP) on the AgNWs could be desorbed, and the AgNW network could be densified. The sheet resistance of the AgNW film on a glass slide is reduced by 60.9% (from 67.5 to 26.4 Ohm sq‑1) with a transmittance of 92.5%. High-resolution transmission electron microscopy analysis indicates that atomic diffusion occurs at the intersection of two AgNWs. Thus, metallurgical bonding on the nanometer scale is achieved across the junctions of the AgNWs, leading to a significant enhancement in the conductivity of the AgNW network.

Separation of organic cations using novel background electrolytes by capillary electrophoresis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steiner, S.; Fritz, J.

2008-02-12

A background electrolyte for capillary electrophoresis containing tris(-hydroxymethyl) aminomethane (THAM) and ethanesulfonic acid (ESA) gives excellent efficiency for separation of drug cations with actual theoretical plate numbers as high as 300,000. However, the analyte cations often elute too quickly and consequently offer only a narrow window for separation. The best way to correct this is to induce a reverse electroosmotic flow (EOF) that will spread out the peaks by slowing their migration rates, but this has always been difficult to accomplish in a controlled manner. A new method for producing a variable EOF is described in which a low variablemore » concentration of tributylammonium- or triethylammonium ESA is added to the BGE. The additive equilibrates with the capillary wall to give it a positive charge and thereby produce a controlled opposing EOF. Excellent separations of complex drug mixtures were obtained by this method.« less

Calculating Permittivity and Dielectric Loss Frequency Spectra for Aqueous Electrolyte Solutions

NASA Astrophysics Data System (ADS)

Odinaev, S.; Makhmadbegov, R. S.

2018-01-01

Analytic expressions for dielectric permittivity factor ɛ1(ω) and dielectric dissipation factor ɛ2(ω) of electrolyte solutions are obtained, based on the ratio between complex factors of dielectric permittivity and specific conductivity. The range of frequency dispersion of dynamic factors ɛ1(ω) and ɛ2(ω) for aqueous solutions of LiCl, NaCl, KCl, and CsCl is considered. Numerical calculations are performed for friction coefficients β a and β b ; relaxation times τ a , τ b , and τ ab ; and factors ɛ1(ω) and ɛ2(ω) in a wide range of variation for ρ; concentration c; temperature T; and frequencies ω. The resulting theoretically calculated ɛ1(ω) and ɛ2(ω) values and the Cole-Cole diagram are in quantitative agreement with experimental data.

Shedding Light on the Oxygen Reduction Reaction Mechanism in Ether-Based Electrolyte Solutions: A Study Using Operando UV-Vis Spectroscopy.

PubMed

Hirshberg, Daniel; Sharon, Daniel; Afri, Michal; Lavi, Ronit; Frimer, Aryeh A; Metoki, Noa; Eliaz, Noam; Kwak, Won-Jin; Sun, Yang-Kook; Aurbach, Doron

2018-04-04

Using UV-vis spectroscopy in conjunction with various electrochemical techniques, we have developed a new effective operando methodology for investigating the oxygen reduction reactions (ORRs) and their mechanisms in nonaqueous solutions. We can follow the in situ formation and presence of superoxide moieties during ORR as a function of solvent, cations, anions, and additives in the solution. Thus, using operando UV-vis spectroscopy, we found evidence for the formation of superoxide radical anions during oxygen reduction in LiTFSI/diglyme electrolyte solutions. Nitro blue tetrazolium (NBT) was used to indicate the presence of superoxide moieties based on its unique spectral response. Indeed, the spectral response of NBT containing solutions undergoing ORR could provide a direct indication for the level of association of the Li cations with the electrolyte anions.

Polyethylene glycol-electrolyte solution (PEG-ES)

MedlinePlus

... electrolytes to prevent dehydration and other serious side effects that may be caused by fluid loss as ... to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in ...

Comparison of a new sulfate-free polyethylene glycol electrolyte lavage solution versus a standard solution for colonoscopy cleansing.

PubMed

DiPalma, J A; Marshall, J B

1990-01-01

A new sulfate-free polyethylene glycol electrolyte lavage solution (SF-ELS) for colonoscopy was formulated to taste better and have less net water and electrolyte secretion and absorption than a standard polyethylene glycolelectrolyte lavage solution (PEG-ELS). At two centers, 157 patients were prospectively randomized to receive SF-ELS or PEG-ELS to assess adequacy of preparation, patient tolerance, weight changes, and various hematologic and biochemical parameters. Physician assessment of colon cleansing showed no difference between those patients receiving SF-ELS (N = 74) or PEG-ELS (N = 78). Eighty-two percent of all preps were found to be "clinically acceptable." Subjects receiving SF-ELS had significantly less fullness and cramps, while PEG-ELS subjects reported less nausea. There was no difference between groups for vomiting, overall discomfort, or willingness to repeat the preparation received. Eighty percent of all patients would repeat the randomized cleansing methods. There were no clinically significant changes in weight or assessed laboratory parameters, with the exception of potassium where PEG-ELS patients had an mean decrease of 0.22 mEq/liter vs. 0.01 mEq/liter for SF-ELS (p less than or equal to 0.01). Patient taste questionnaires in those patients expressing a preference showed a preference for SF-ELS (76.6%) over PEG-ELS (23.4%) (p less than or equal to 0.001). Thirty-two (22.5%) of total respondents indicated no preference. We conclude that SF-ELS when compared with PEG-ELS is similarly a safe and effective method of colon cleansing for colonoscopy that is well tolerated. Patients prefer the taste of the new solution.

Effect of Dilute Apple Juice and Preferred Fluids vs Electrolyte Maintenance Solution on Treatment Failure Among Children With Mild Gastroenteritis: A Randomized Clinical Trial.

PubMed

Freedman, Stephen B; Willan, Andrew R; Boutis, Kathy; Schuh, Suzanne

2016-05-10

Gastroenteritis is a common pediatric illness. Electrolyte maintenance solution is recommended to treat and prevent dehydration. Its advantage in minimally dehydrated children is unproven. To determine if oral hydration with dilute apple juice/preferred fluids is noninferior to electrolyte maintenance solution in children with mild gastroenteritis. Randomized, single-blind noninferiority trial conducted between the months of October and April during the years 2010 to 2015 in a tertiary care pediatric emergency department in Toronto, Ontario, Canada. Study participants were children aged 6 to 60 months with gastroenteritis and minimal dehydration. Participants were randomly assigned to receive color-matched half-strength apple juice/preferred fluids (n=323) or apple-flavored electrolyte maintenance solution (n=324). Oral rehydration therapy followed institutional protocols. After discharge, the half-strength apple juice/preferred fluids group was administered fluids as desired; the electrolyte maintenance solution group replaced losses with electrolyte maintenance solution. The primary outcome was a composite of treatment failure defined by any of the following occurring within 7 days of enrollment: intravenous rehydration, hospitalization, subsequent unscheduled physician encounter, protracted symptoms, crossover, and 3% or more weight loss or significant dehydration at in-person follow-up. Secondary outcomes included intravenous rehydration, hospitalization, and frequency of diarrhea and vomiting. The noninferiority margin was defined as a difference between groups of 7.5% for the primary outcome and was assessed with a 1-sided α=.025. If noninferiority was established, a 1-sided test for superiority was conducted. Among 647 randomized children (mean age, 28.3 months; 331 boys [51.1%]; 441 (68.2%) without evidence of dehydration), 644 (99.5%) completed follow-up. Children who were administered dilute apple juice experienced treatment failure less often than those

How Does the Alkyl Chain Length of an Ionic Liquid Influence Solute Rotation in the Presence of an Electrolyte?

PubMed

Prabhu, Sugosh R; Dutt, G B

2016-12-29

Fluorescence anisotropies of a nonpolar solute, 9-phenylanthracene (9-PA), have been measured in 1-alkyl-3-methylimidazolium (alkyl = methyl, butyl, octyl, and dodecyl) bis(trifluoromethylsulfonyl)imides ([RMIM][Tf 2 N]) with varying amounts (0-0.3 mole fraction) of lithium bis(trifluoromethylsulfonyl)imide (LiTf 2 N). This study has been carried out to understand how the length of the alkyl chain and the concentration of the electrolyte influence the rotational diffusion of a nonpolar solute. It has been observed that the addition of an electrolyte to the ionic liquid increases the bulk viscosity of the system significantly, as the Li + cations strongly coordinate with the [Tf 2 N] anions in the polar domains. The reorientation times of 9-PA have been analyzed with the aid of Stokes-Einstein-Debye hydrodynamic (SED) theory, and they fall within the broad limits set by the hydrodynamic slip and stick boundary conditions. However, deviations from the SED theory have been noticed upon addition of LiTf 2 N, and the influence of the electrolyte is more pronounced in the case of ionic liquids with shorter alkyl chains. The observed trends have been rationalized in terms of electrolyte-induced structural changes in these ionic liquids.

Bio-sorbable, liquid electrolyte gated thin-film transistor based on a solution-processed zinc oxide layer.

PubMed

Singh, Mandeep; Palazzo, Gerardo; Romanazzi, Giuseppe; Suranna, Gian Paolo; Ditaranto, Nicoletta; Di Franco, Cinzia; Santacroce, Maria Vittoria; Mulla, Mohammad Yusuf; Magliulo, Maria; Manoli, Kyriaki; Torsi, Luisa

2014-01-01

Among the metal oxide semiconductors, ZnO has been widely investigated as a channel material in thin-film transistors (TFTs) due to its excellent electrical properties, optical transparency and simple fabrication via solution-processed techniques. Herein, we report a solution-processable ZnO-based thin-film transistor gated through a liquid electrolyte with an ionic strength comparable to that of a physiological fluid. The surface morphology and chemical composition of the ZnO films upon exposure to water and phosphate-buffered saline (PBS) are discussed in terms of the operation stability and electrical performance of the ZnO TFT devices. The improved device characteristics upon exposure to PBS are associated with the enhancement of the oxygen vacancies in the ZnO lattice due to Na(+) doping. Moreover, the dissolution kinetics of the ZnO thin film in a liquid electrolyte opens the possible applicability of these devices as an active element in "transient" implantable systems.

Recovery of mercury from mercury compounds via electrolytic methods

DOEpatents

Grossman, Mark W.; George, William A.

1991-01-01

A process for electrolytically recovering mercury from mercury compounds is provided. In one embodiment, Hg is recovered from Hg.sub.2 Cl.sub.2 employing as the electrolyte solution a mixture of HCl and H.sub.2 O. In another embodiment, Hg is electrolytically recovered from HgO wherein the electrolyte solution is comprised of glacial acetic acid and H.sub.2 O. Also provided is an apparatus for producing isotopically enriched mercury compounds in a reactor and then transporting the dissolved compounds into an electrolytic cell where mercury ions are electrolytically reduced and elemental mercury recovered from the mercury compounds.

Recovery of mercury from mercury compounds via electrolytic methods

DOEpatents

Grossman, Mark W.; George, William A.

1988-01-01

A process for electrolytically recovering mercury from mercury compounds is provided. In one embodiment, Hg is recovered from Hg.sub.2 Cl.sub.2 employing as the electrolyte solution a mixture of HCl and H.sub.2 O. In another embodiment, Hg is electrolytically recovered from HgO wherein the electrolyte solution is comprised of glacial acetic acid and H.sub.2 O. Also provided is an apparatus for producing isotopically enriched mercury compounds in a reactor and then transporting the dissolved compounds into an electrolytic cell where mercury ions are electrolytically reduced and elemental mercury recovered from the mercury compounds.

Recovery of mercury from mercury compounds via electrolytic methods

DOEpatents

Grossman, Mark W.; George, William A.

1989-01-01

A process for electrolytically recovering mercury from mercury compounds is provided. In one embodiment, Hg is recovered from Hg.sub.2 Cl.sub.2 employing as the electrolyte solution a mixture of HCl and H.sub.2 O. In another embodiment, Hg is electrolytically recovered from HgO wherein the electrolyte solution is comprised of glacial acetic acid and H.sub.2 O. Also provided is an apparatus for producing isotopically enriched mercury compounds in a reactor and then transporting the dissolved compounds into an electrolytic cell where mercury ions are electrolytically reduced and elemental mercury recovered from the mercury compounds.

Recovery of mercury from mercury compounds via electrolytic methods

DOEpatents

Grossman, M.W.; George, W.A.

1991-06-18

A process for electrolytically recovering mercury from mercury compounds is provided. In one embodiment, Hg is recovered from Hg[sub 2]Cl[sub 2] employing as the electrolyte solution a mixture of HCl and H[sub 2]O. In another embodiment, Hg is electrolytically recovered from HgO wherein the electrolyte solution is comprised of glacial acetic acid and H[sub 2]O. Also provided is an apparatus for producing isotopically enriched mercury compounds in a reactor and then transporting the dissolved compounds into an electrolytic cell where mercury ions are electrolytically reduced and elemental mercury recovered from the mercury compounds. 3 figures.

Recovery of mercury from mercury compounds via electrolytic methods

DOEpatents

Grossman, M.W.; George, W.A.

1989-11-07

A process for electrolytically recovering mercury from mercury compounds is provided. In one embodiment, Hg is recovered from Hg[sub 2]Cl[sub 2] employing as the electrolyte solution a mixture of HCl and H[sub 2]O. In another embodiment, Hg is electrolytically recovered from HgO wherein the electrolyte solution is comprised of glacial acetic acid and H[sub 2]O. Also provided is an apparatus for producing isotopically enriched mercury compounds in a reactor and then transporting the dissolved compounds into an electrolytic cell where mercury ions are electrolytically reduced and elemental mercury recovered from the mercury compounds. 3 figs.

Theory of space-charge polarization for determining ionic constants of electrolytic solutions

NASA Astrophysics Data System (ADS)

Sawada, Atsushi

2007-06-01

A theoretical expression of the complex dielectric constant attributed to space-charge polarization has been derived under an electric field calculated using Poisson's equation considering the effects of bound charges on ions. The frequency dependence of the complex dielectric constant of chlorobenzene solutions doped with tetrabutylammonium tetraphenylborate (TBATPB) has been analyzed using the theoretical expression, and the impact of the bound charges on the complex dielectric constant has been clarified quantitatively in comparison with a theory that does not consider the effect of the bound charges. The Stokes radius of TBA +(=TPB-) determined by the present theory shows a good agreement with that determined by conductometry in the past; hence, the present theory should be applicable to the direct determination of the mobility of ion species in an electrolytic solution without the need to measure ionic limiting equivalent conductance and transport number.

Reaction of Cl- ions in electrolyte solution induced electrical discharge plasma in the presence of argon fine bubbles

NASA Astrophysics Data System (ADS)

Hayashi, Yui; Takada, Noriharu; Wahyudiono, Kanda, Hideki; Goto, Motonobu

2017-05-01

Active chlorine species such as chlorine molecules and hypochlorous acid have been known as high performance sanitizers. They would act more reactive on chemical and biological substances when an electrical discharge was introduced in water containing an electrolyte substance. Here, the reaction of chloride (Cl-) ions were examined by introducing of a pulsed discharge plasma in sodium chloride (NaCl) solution as an electrolyte solution at room temperature. The results show that a large electrical current generated by the pulsed discharge plasma affected the reaction of Cl- ions to result available chlorine. The reaction pathway for available chlorine production was assumed similar with the reaction pathway as electrolysis. A pulsed discharge plasma in NaCl solution in the presence of argon (Ar) fine bubbles exhibited intense emissions and high electron density compared to when no Ar fine bubbles were introduced. At these conditions, the dissociation reaction rate of water increased drastically leads to the formation of 0 atoms. As a result, the reaction of Cl- ions and the available chlorine generation were also increased.

Reduced Capillary Length Scale in the Application of Ostwald Ripening Theory to the Coarsening of Charged Colloidal Crystals in Electrolyte Solutions

NASA Astrophysics Data System (ADS)

Rowe, Jeffrey D.; Baird, James K.

2007-06-01

A colloidal crystal suspended in an electrolyte solution will ordinarily exchange ions with the surrounding solution and develop a net surface charge density and a corresponding double layer. The interfacial tension of the charged surface has contributions arising from: (a) background interfacial tension of the uncharged surface, (b) the entropy associated with the adsorption of ions on the surface, and (c) the polarizing effect of the electrostatic field within the double layer. The adsorption and polarization effects make negative contributions to the surface free energy and serve to reduce the interfacial tension below the value to be expected for the uncharged surface. The diminished interfacial tension leads to a reduced capillary length scale. According to the Ostwald ripening theory of particle coarsening, the reduced capillary length will cause the solute supersaturation to decay more rapidly and the colloidal particles to be smaller in size and greater in number than in the absence of the double layer. Although the length scale for coarsening should be little affected in the case of inorganic colloids, such as AgI, it should be greatly reduced in the case of suspensions of protein crystals, such as apoferritin, catalase, and thaumatin.

Does fluid resuscitation with balanced solutions induce electrolyte and metabolic abnormalities? An in vitro assessment.

PubMed

Krzych, Łukasz J; Czempik, Piotr F

2017-01-01

Popular intravenous fluids in clinical use may have an impact on electrolyte concentration and metabolic balance and should be considered as powerful pharmacological agents. There is a growing body of evidence that fluid therapy should be more individualised and preferably based on balanced solutions. We sought to investigate the impact of three commonly used balanced fluids on electrolytes and metabolic equilibrium in an in vitro setting. Study group comprised 32 healthy male volunteers (without history of any acute/chronic disorder or known metabolic abnormality), aged 21-35 (29 ± 4) years, weight 59-103 (81.2 ± 9.8) kg, from whom blood samples were withdrawn. The whole blood was diluted in 4:1 ratio with the study solutions to make an end-concentration of 20 vol.% of each solution. The test solutions included balanced crystalloid (Plasmalyte®, Baxter, Poland [PL]), succinylated gelatin (Geloplasma®, Fresenius Kabi, Poland [GEL]) and 6% HES 130/0.4 (Volulyte®, Fresenius Kabi, Poland [HES]). All fluids caused comparable degree of haemodilution. PL and GEL decreased (104 mmol/L, interquartile range [IQR] 103-105; and 106 mmol/L, IQR 105-107.5, respectively), whereas HES increased the concentration of Cl- to 109 (IQR 108-110) mmol/L. PL and HES decreased (136, IQR 136-137 mmol/L; and 138 mmol/L, IQR 137-139, respectively), whereas GEL increased the Na+ level to 140.5 (IQR 140-141) mmol/L. PL and HES decreased osmolality (277.2 mOsm/kg, IQR 275.7-278.4; and 280.9 mOsm/kg, IQR 279.3-282.0, respectively). GEL increased it to 285.7 (IQR 283.7-286.8) mOsm/kg. All test solutions caused a similar statistically significant (p < 0.05) drop in base excess and bicarbonate concentration, and these fell outside the reference values. Due to its composition, GEL caused a significant increase in lactate concentration. HES and GEL caused a statistically significant drop in strong ion difference value. Due to high lactate level, the effect of GEL was most pronounced. Balanced

Methods and electrolytes for electrodeposition of smooth films

DOEpatents

Zhang, Jiguang; Xu, Wu; Graff, Gordon L; Chen, Xilin; Ding, Fei; Shao, Yuyan

2015-03-17

Electrodeposition involving an electrolyte having a surface-smoothing additive can result in self-healing, instead of self-amplification, of initial protuberant tips that give rise to roughness and/or dendrite formation on the substrate and/or film surface. For electrodeposition of a first conductive material (C1) on a substrate from one or more reactants in an electrolyte solution, the electrolyte solution is characterized by a surface-smoothing additive containing cations of a second conductive material (C2), wherein cations of C2 have an effective electrochemical reduction potential in the solution lower than that of the reactants.

Plasma Electrolytic Oxidation Coatings on Pure Ti Substrate: Effects of Na3PO4 Concentration on Morphology and Corrosion Behavior of Coatings in Ringer's Physiological Solution

NASA Astrophysics Data System (ADS)

Roknian, Masoud; Fattah-alhosseini, Arash; Gashti, Seyed Omid

2018-03-01

Plasma electrolytic oxidation has been used as a relatively new method for applying ceramic coatings having different features. In the present study, commercially pure titanium is used as substrate, and effects of trisodium phosphate electrolyte concentration on the microstructure, as well as corrosion behavior of the coating in Ringer's physiological solution are investigated. The morphology and phase compositions of coatings were analyzed by using scanning electron microscopy (SEM) and x-ray diffraction patterns. The study on the corrosion behavior of samples in a Ringer's physiological solution was carried out using open-circuit potential potentiodynamic polarization and electrochemical impedance spectroscopy. The results of electrochemical analysis proved that higher concentration of phosphate electrolyte leads to increase in the corrosion resistance of applied coatings. Accordingly, obtained results revealed that the optimum electrolyte concentration for the best corrosion behavior was 20 g L-1. Furthermore, SEM images and reduction in the dielectric breakdown potential indicated that increase in the electrolyte concentration leads to morphological improvement and smoothening of the surface.

Inhibition of calcium oxalate monohydrate growth by citrate and the effect of the background electrolyte

NASA Astrophysics Data System (ADS)

Weaver, Matthew L.; Qiu, S. Roger; Hoyer, John R.; Casey, William H.; Nancollas, George H.; De Yoreo, James J.

2007-08-01

Pathological mineralization is a common phenomenon in broad range of plants and animals. In humans, kidney stone formation is a well-known example that afflicts approximately 10% of the population. Of the various calcium salt phases that comprise human kidney stones, the primary component is calcium oxalate monohydrate (COM). Citrate, a naturally occurring molecule in the urinary system and a common therapeutic agent for treating stone disease, is a known inhibitor of COM. Understanding the physical mechanisms of citrate inhibition requires quantification of the effects of both background electrolytes and citrate on COM step kinetics. Here we report the results of an in situ AFM study of these effects, in which we measure the effect of the electrolytes LiCl, NaCl, KCl, RbCl, and CsCl, and the dependence of step speed on citrate concentration for a range of COM supersaturations. We find that varying the background electrolyte results in significant differences in the measured step speeds and in step morphology, with KCl clearly producing the smallest impact and NaCl the largest. The kinetic coefficient for the former is nearly three times larger than for the latter, while the steps change from smooth to highly serrated when KCl is changed to NaCl. The results on the dependence of step speed on citrate concentration show that citrate produces a dead zone whose width increases with citrate concentration as well as a continual reduction in kinetic coefficient with increasing citrate level. We relate these results to a molecular-scale view of inhibition that invokes a combination of kink blocking and step pinning. Furthermore, we demonstrate that the classic step-pinning model of Cabrera and Vermilyea (C-V model) does an excellent job of predicting the effect of citrate on COM step kinetics provided the model is reformulated to more realistically account for impurity adsorption, include an expression for the Gibbs-Thomson effect that is correct for all supersaturations

Evaluation of an oral electrolyte solution for treatment of mild to moderate dehydration in dogs with hemorrhagic diarrhea.

PubMed

Reineke, Erica L; Walton, Karie; Otto, Cynthia M

2013-09-15

To determine the safety and efficacy of an electrolyte solution for oral administration (OES) for the correction of mild to moderate dehydration associated with hemorrhagic diarrhea in dogs. Nonrandomized, noncontrolled clinical trial. 20 dogs that had hemorrhagic diarrhea with < 3 episodes of vomiting. All dogs underwent testing for parvovirus infection, were given maropitant citrate to control emesis, and were offered an OES. Intravenous crystalloid fluid administration was performed when dogs refused the OES or had vomiting, a 5% increase in PCV, 5% decrease in body weight, serum creatinine or BUN concentration higher than at admission, or clinically important alterations in blood electrolyte or serum glucose concentrations. 13 (65%) dogs voluntarily consumed the OES; 7 (35%) dogs refused the OES and received a balanced electrolyte solution IV instead. All 13 dogs in the OES group consumed the solution ≤ 5 hours after hospital admission. Eight and 16 hours after admission, PCV and serum total protein and BUN concentrations were significantly lower than at hospital admission in the OES group, whereas no significant changes were identified in venous blood pH, base excess, and concentrations of sodium, potassium, chloride, ionized calcium, ionized magnesium, and lactate. The cost of treatment was significantly less for the OES group than for the IV treated group. Rehydration therapy with an OES was effective and safe in dogs with mild to moderate dehydration associated with hemorrhagic diarrhea. Potential benefits of this treatment approach for gastroenteritis in dogs, compared with traditional IV fluid administration, include lower owner-related veterinary costs and decreased staff time associated with treatment.

Thermodynamic characteristics of protolytic equilibria of L-serine in aqueous solutions

NASA Astrophysics Data System (ADS)

Kochergina, L. A.; Volkov, A. V.; Khokhlova, E. A.; Krutova, O. N.

2011-05-01

The heat effects of the reaction of aqueous solution of L-serine with aqueous solutions of HNO3 and KOH were determined by calorimetry at temperatures of 288.15, 298.15, and 308.15 K, and ionic strength values of 0.2, 0.5, and 1.0 (background electrolyte, KNO3). Standard thermodynamic characteristics (Δr H o, Δr G o, Δr S o, Δ C {/p o}) of the acid-base reactions in aqueous solutions of L-serine were calculated. The effect of the concentration of background electrolyte and temperature on the heats of dissociation of amino acid was considered. The combustion energy of L-serine by bomb calorimetry in the medium of oxygen was determined. The standard combustion and formation enthalpies of crystalline L-serine were calculated. The heats of dissolution of crystalline L-serine in water and solutions of potassium hydroxide at 298.15 K were measured by direct calorimetry. The standard enthalpies of formation of L-serine and products of its dissociation in aqueous solution were calculated.

Background-Error Correlation Model Based on the Implicit Solution of a Diffusion Equation

DTIC Science & Technology

2010-01-01

1 Background- Error Correlation Model Based on the Implicit Solution of a Diffusion Equation Matthew J. Carrier* and Hans Ngodock...4. TITLE AND SUBTITLE Background- Error Correlation Model Based on the Implicit Solution of a Diffusion Equation 5a. CONTRACT NUMBER 5b. GRANT...2001), which sought to model error correlations based on the explicit solution of a generalized diffusion equation. The implicit solution is

Non-aqueous electrolytes for lithium ion batteries

DOEpatents

Chen, Zonghai; Amine, Khalil

2015-11-12

The present invention is generally related to electrolytes containing anion receptor additives to enhance the power capability of lithium-ion batteries. The anion receptor of the present invention is a Lewis acid that can help to dissolve LiF in the passivation films of lithium-ion batteries. Accordingly, one aspect the invention provides electrolytes comprising a lithium salt; a polar aprotic solvent; and an anion receptor additive; and wherein the electrolyte solution is substantially non-aqueous. Further there are provided electrochemical devices employing the electrolyte and methods of making the electrolyte.

Finite-size effects in simulations of electrolyte solutions under periodic boundary conditions

NASA Astrophysics Data System (ADS)

Thompson, Jeffrey; Sanchez, Isaac

The equilibrium properties of charged systems with periodic boundary conditions may exhibit pronounced system-size dependence due to the long range of the Coulomb force. As shown by others, the leading-order finite-size correction to the Coulomb energy of a charged fluid confined to a periodic box of volume V may be derived from sum rules satisfied by the charge-charge correlations in the thermodynamic limit V -> ∞ . In classical systems, the relevant sum rule is the Stillinger-Lovett second-moment (or perfect screening) condition. This constraint implies that for large V, periodicity induces a negative bias of -kB T(2 V) - 1 in the total Coulomb energy density of a homogeneous classical charged fluid of given density and temperature. We present a careful study of the impact of such finite-size effects on the calculation of solute chemical potentials from explicit-solvent molecular simulations of aqueous electrolyte solutions. National Science Foundation Graduate Research Fellowship Program, Grant No. DGE-1610403.

The Significance of the Origin of Physical Chemistry for Physical Chemistry Education: The Case of Electrolyte Solution Chemistry

ERIC Educational Resources Information Center

de Berg, Kevin Charles

2014-01-01

Physical Chemistry's birth was fraught with controversy, a controversy about electrolyte solution chemistry which has much to say about how scientific knowledge originates, matures, and responds to challenges. This has direct implications for the way our students are educated in physical chemistry in particular and science in general. The…

Electroosmotic flow in capillary channels filled with nonconstant viscosity electrolytes: exact solution of the Navier-Stokes equation.

PubMed

Otevrel, Marek; Klepárník, Karel

2002-10-01

The partial differential equation describing unsteady velocity profile of electroosmotic flow (EOF) in a cylindrical capillary filled with a nonconstant viscosity electrolyte was derived. Analytical solution, based on the general Navier-Stokes equation, was found for constant viscosity electrolytes using the separation of variables (Fourier method). For the case of a nonconstant viscosity electrolyte, the steady-state velocity profile was calculated assuming that the viscosity decreases exponentially in the direction from the wall to the capillary center. Since the respective equations with nonconstant viscosity term are not solvable in general, the method of continuous binding conditions was used to solve this problem. In this method, an arbitrary viscosity profile can be modeled. The theoretical conclusions show that the relaxation times at which an EOF approaches the steady state are too short to have an impact on a separation process in any real systems. A viscous layer at the wall affects EOF significantly, if it is thicker than the Debye length of the electric double layer. The presented description of the EOF dynamics is applicable to any microfluidic systems.

Negative Transference Numbers in Polymer Electrolytes

NASA Astrophysics Data System (ADS)

Pesko, Danielle; Timachova, Ksenia; Balsara, Nitash

Energy density and safety of conventional lithium-ion batteries is limited by the use of flammable organic liquids as a solvent for lithium salts. Polymer electrolytes have the potential to address both limitations. The poor performance of batteries with polymer electrolytes is generally attributed to low ionic conductivity. The purpose of our work is to show that another transport property, the cation transference number, t +, of polymer electrolytes is fundamentally different from that of conventional electrolytes. Our experimental approach, based on concentrated solution theory, indicates that t + of mixtures of poly(ethylene oxide) and LiTFSI salt are negative over most of the accessible concentration window. In contrast, approaches based on dilute solution theory suggest that t + in the same system is positive. In addition to presenting a new approach for determining t +, we also present data obtained from the steady-state current method, pulsed-field-gradient NMR, and the current-interrupt method. Discrepancies between different approaches are resolved. Our work implies that in the absence of concentration gradients, the net fluxes of both cations and anions are directed toward the positive electrode. Conventional liquid electrolytes do not suffer from this constraint.

On the thermal behavior of model Li-Li xCoO 2 systems containing ionic liquids in standard electrolyte solutions

NASA Astrophysics Data System (ADS)

Larush, L.; Borgel, V.; Markevich, E.; Haik, O.; Zinigrad, E.; Aurbach, D.; Semrau, G.; Schmidt, M.

We report herein on the possibility of using ionic liquids (ILs) as additives to conventional electrolyte solutions, based on alkyl carbonates and LiPF 6 for attenuating thermal reactions in Li battery systems. As a model, a Li-Li 0.5CoO 2 system was used. The ionic liquids chosen included cations based on derivatives of pyrrolidinium and imidazolium, and the anions bioxalato borate (C 4O 8B -, BOB), (CH 3SO 2) 2N - (TFSI), and PF 3(C 2S 5) 3 - (FAP). The thermal behavior of solutions alone, solutions with Li metal, Li 0.5CoO 2 and Li metal + Li 0.5CoO 2 was studied. It was found that the presence of 10% of ILs, with derivatives of pyrrolidinium cations and FAP or TFSI anions in standard EC-DMC/LiPF 6 solutions, improves considerably the thermal stability of Li 0.5CoO 2 in electrolyte solutions. The onset temperatures of the thermal reactions of Li 0.5CoO 2 with solution species are higher and their heat evolution is considerably lower, when they contain these ionic liquids as additives. This finding opens the door for further studies and optimization of the use of selected ILs as additives that may improve the safety features of Li-ion batteries.

Ionic liquids, electrolyte solutions including the ionic liquids, and energy storage devices including the ionic liquids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gering, Kevin L.; Harrup, Mason K.; Rollins, Harry W.

2015-12-08

An ionic liquid including a phosphazene compound that has a plurality of phosphorus-nitrogen units and at least one pendant group bonded to each phosphorus atom of the plurality of phosphorus-nitrogen units. One pendant group of the at least one pendant group comprises a positively charged pendant group. Additional embodiments of ionic liquids are disclosed, as are electrolyte solutions and energy storage devices including the embodiments of the ionic liquid.

Successful Stabilization of Graphene Oxide in Electrolyte Solutions: Enhancement of Bio-functionalization and Cellular Uptake

PubMed Central

Hong, Bong Jin; Compton, Owen C.; An, Zhi; Eryzazici, Ibrahim; Nguyen, SonBinh T.

2013-01-01

Aqueous dispersions of graphene oxide are inherently unstable in the presence of electrolytes, which screen the electrostatic surface charge on these nanosheets and induce irreversible aggregation. Two complementary strategies, utilizing either electrostatic or steric stabilization, have been developed to enhance the stability of graphene oxide in electrolyte solutions, allowing it to stay dispersed in cell culture media and serum. The electrostatic stabilization approach entails further oxidation of graphene oxide to low C/O ratio (~1.03) and increases ionic tolerance of these nanosheets. The steric stabilization technique employs an amphiphilic block copolymer that serves as a non-covalently bound surfactant to minimize the aggregate-induced nanosheets-nanosheet interactions. Both strategies can stabilize graphene oxide nanosheets with large dimensions (>300 nm) in biological media, allowing for an enhancement of >250% in the bioconjugation efficiency of streptavidin in comparison to untreated nanosheets. Notably, both strategies allow the stabilized nanosheets to be readily uptake by cells, demonstrating their excellent performance as potential drug delivery vehicles. PMID:22017285

Second harmonic generation study of malachite green adsorption at the interface between air and an electrolyte solution: observing the effect of excess electrical charge density at the interface.

PubMed

Song, Jinsuk; Kim, Mahn Won

2010-03-11

Understanding the differential adsorption of ions at the interface of an electrolyte solution is very important because it is closely related, not only to the fundamental aspects of biological systems, but also to many industrial applications. We have measured the excess interfacial negative charge density at air-electrolyte solution interfaces by using resonant second harmonic generation of oppositely charged probe molecules. The excess charge density increased with the square root of the bulk electrolyte concentration. A new adsorption model that includes the electrostatic interaction between adsorbed molecules is proposed to explain the measured adsorption isotherm, and it is in good agreement with the experimental results.

Background photobleaching in raman spectra of aqueous solutions of plant toxins

NASA Astrophysics Data System (ADS)

Brandt, Nikolai N.; Chikishev, Andrey Y.; Tonevitsky, Alexander G.

2002-05-01

Kinetics of background photobleaching in Raman spectra of aqueous solutions of ricin, ricin agglutinin and ricin binding subunit were measured. It was found that the spectrum of Raman background changes upon laser irradiation. Background intensity is lower for the samples with lower molecular weight. Photobleaching is characterized by oscillations in the multi exponentially decaying intensity.

Enhancing Capacity Performance by Utilizing the Redox Chemistry of the Electrolyte in a Dual-Electrolyte Sodium-Ion Battery.

PubMed

Senthilkumar, Sirugaloor Thangavel; Bae, Hyuntae; Han, Jinhyup; Kim, Youngsik

2018-05-04

A strategy is described to increase charge storage in a dual electrolyte Na-ion battery (DESIB) by combining the redox chemistry of the electrolyte with a Na + ion de-insertion/insertion cathode. Conventional electrolytes do not contribute to charge storage in battery systems, but redox-active electrolytes augment this property via charge transfer reactions at the electrode-electrolyte interface. The capacity of the cathode combined with that provided by the electrolyte redox reaction thus increases overall charge storage. An aqueous sodium hexacyanoferrate (Na 4 Fe(CN) 6 ) solution is employed as the redox-active electrolyte (Na-FC) and sodium nickel Prussian blue (Na x -NiBP) as the Na + ion insertion/de-insertion cathode. The capacity of DESIB with Na-FC electrolyte is twice that of a battery using a conventional (Na 2 SO 4 ) electrolyte. The use of redox-active electrolytes in batteries of any kind is an efficient and scalable approach to develop advanced high-energy-density storage systems. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electrolyte and plasma changes after ingestion of pickle juice, water, and a common carbohydrate-electrolyte solution.

PubMed

Miller, Kevin C; Mack, Gary; Knight, Kenneth L

2009-01-01

Health care professionals advocate that athletes who are susceptible to exercise-associated muscle cramps (EAMCs) should moderately increase their fluid and electrolyte intake by drinking sport drinks. Some clinicians have also claimed drinking small volumes of pickle juice effectively relieves acute EAMCs, often alleviating them within 35 seconds. Others fear ingesting pickle juice will enhance dehydration-induced hypertonicity, thereby prolonging dehydration. To determine if ingesting small quantities of pickle juice, a carbohydrate-electrolyte (CHO-e) drink, or water increases plasma electrolytes or other selected plasma variables. Crossover study. Exercise physiology laboratory. Nine euhydrated, healthy men (age = 25 +/- 2 years, height = 179.4 +/- 7.2 cm, mass = 86.3 +/- 15.9 kg) completed the study. Resting blood samples were collected preingestion (-0.5 minutes); immediately postingestion (0 minutes); and at 1, 5, 10, 15, 20, 25, 30, 45, and 60 minutes postingestion of 1 mL/kg body mass of pickle juice, CHO-e drink, or tap water. Plasma sodium concentration, plasma magnesium concentration, plasma calcium concentration, plasma potassium concentration, plasma osmolality, and changes in plasma volume were analyzed. Urine specific gravity, osmolality, and volume were also measured to characterize hydration status. Mean fluid intake was 86.3 +/- 16.7 mL. Plasma sodium concentration, plasma magnesium concentration, plasma calcium concentration, plasma osmolality, and plasma volume did not change during the 60 minutes after ingestion of each fluid (P >or= .05). Water ingestion slightly decreased plasma potassium concentration at 60 minutes (0.21 +/- 0.14 mg/dL [0.21 +/- 0.14 mmol/L]; P electrolyte concentrations, plasma osmolality, or plasma volume in rested, euhydrated men. Concern that ingesting these volumes of pickle juice might exacerbate an

Charge-discharge characteristics of nickel/zinc battery with polymer hydrogel electrolyte

NASA Astrophysics Data System (ADS)

Iwakura, Chiaki; Murakami, Hiroki; Nohara, Shinji; Furukawa, Naoji; Inoue, Hiroshi

A new nickel/zinc (Ni/Zn) battery was assembled by using polymer hydrogel electrolyte prepared from cross-linked potassium poly(acrylate) and KOH aqueous solution, and its charge-discharge characteristics were investigated. The experimental Ni/Zn cell with the polymer hydrogel electrolyte exhibited well-defined charge-discharge curves and remarkably improved charge-discharge cycle performance, compared to that with a KOH aqueous solution. Moreover, it was found that dendritic growth hardly occurred on the zinc electrode surface during charge-discharge cycles in the polymer hydrogel electrolyte. These results indicate that the polymer hydrogel electrolyte can successfully be used in Ni/Zn batteries as an electrolyte with excellent performance.

Colloidal Electrolytes and the Critical Micelle Concentration

ERIC Educational Resources Information Center

Knowlton, L. G.

1970-01-01

Describes methods for determining the Critical Micelle Concentration of Colloidal Electrolytes; methods described are: (1) methods based on Colligative Properties, (2) methods based on the Electrical Conductivity of Colloidal Electrolytic Solutions, (3) Dye Method, (4) Dye Solubilization Method, and (5) Surface Tension Method. (BR)

Line of charges in electrolyte solution near a half-space I. Counterion condensation.

PubMed

Tang, Tian; Jagota, Anand; Hui, Chung-Yuen

2006-07-15

The effect of a half-space on counterion condensation around a line of charges in electrolyte solution is examined in the framework of Debye-Hückel electrostatics. The half-space substrate is allowed to be a conductor, a dielectric, or a semiconductor. Counterions are predicted to be released completely as the line of charges approaches a conducting substrate. When it approaches a dielectric substrate, depending on the ratio of solvent to substrate dielectric constant, there are three possibilities: (1) epsilon(sol)/epsilon(sub) < 1; the counterions are partially (or completely) released; (2) epsilon(sol)/epsilon(sub) = 1; the amount of condensation remains unchanged; and (3) epsilon(sol)/epsilon(sub) > 1; more counterions condense. Depending on the relative magnitude of screening lengths in the semiconductor and in the solution, its effect on condensation follows either that of a metal or that of a dielectric. For the case of a moderately doped silicon substrate, condensation is predicted to be similar to that for a dielectric.

Elucidating Solvation Structures for Rational Design of Multivalent Electrolytes-A Review.

PubMed

Rajput, Nav Nidhi; Seguin, Trevor J; Wood, Brandon M; Qu, Xiaohui; Persson, Kristin A

2018-04-26

Fundamental molecular-level understanding of functional properties of liquid solutions provides an important basis for designing optimized electrolytes for numerous applications. In particular, exhaustive knowledge of solvation structure, stability, and transport properties is critical for developing stable electrolytes for fast-charging and high-energy-density next-generation energy storage systems. Accordingly, there is growing interest in the rational design of electrolytes for beyond lithium-ion systems by tuning the molecular-level interactions of solvate species present in the electrolytes. Here we present a review of the solvation structure of multivalent electrolytes and its impact on the electrochemical performance of these batteries. A direct correlation between solvate species present in the solution and macroscopic properties of electrolytes is sparse for multivalent electrolytes and contradictory results have been reported in the literature. This review aims to illustrate the current understanding, compare results, and highlight future needs and directions to enable the deep understanding needed for the rational design of improved multivalent electrolytes.

Chemical modification of electrolytes for lithium batteries

NASA Astrophysics Data System (ADS)

Afanas'ev, Vladimir N.; Grechin, Aleksandr G.

2002-09-01

Modern approaches to modifying chemically electrolytes for lithium batteries are analysed with the aim of optimising the charge-transfer processes in liquid-phase and solid (polymeric) media. The main regularities of transport properties of lithium electrolyte solutions containing complex (encapsulated) ions in aprotic solvents and polymers are discussed. The prospects for the development of electrolytic solvosystems with the chain (ionotropic) mechanism of conduction with respect to lithium ions are outlined. The bibliography includes 126 references.

Multi-layered proton-conducting electrolyte

DOEpatents

Lee, Tae H.; Dorris, Stephen E.; Balachandran, Uthamalingam

2017-06-27

The present invention provides a multilayer anode/electrolyte assembly comprising a porous anode substrate and a layered solid electrolyte in contact therewith. The layered solid electrolyte includes a first dense layer of yttrium-doped barium zirconate (BZY), optionally including another metal besides Y, Ba, and Zr (e.g., a lanthanide metal such as Pr) on one surface thereof, a second dense layer of yttrium-doped barium cerate (BCY), and an interfacial layer between and contacting the BZY and BCY layers. The interfacial layer comprises a solid solution of the BZY and BCY electrolytes. The porous anode substrate comprises at least one porous ceramic material that is stable to carbon dioxide and water (e.g., porous BZY), as well as an electrically conductive metal and/or metal oxide (e.g., Ni, NiO, and the like).

Effect of cations in the background electrolyte on the adsorption kinetics of copper and cadmium and the isoelectric point of imogolite.

PubMed

Arancibia-Miranda, Nicolás; Silva-Yumi, Jorge; Escudey, Mauricio

2015-12-15

Modification of surface charge and changes in the isoelectric point (IEP) of synthetic imogolite were studied for various cations in the background electrolyte (K(+), NH4(+), Mg(2+), and Ca(2+)). From the electrophoretic mobility data, it was established that the K(+) (KCl) concentration does not affect the IEP of imogolite; therefore, KCl is a suitable background electrolyte. In terms of the magnitude of changes in the IEP and surface charge, the cations may be ranked in the following order: Mg(2+)≈Ca(2+)>NH4(+)>K(+). Four different kinetic models were used to evaluate the influence of Mg(2+), Ca(2+), NH4(+), and K(+) on the adsorption of Cd and Cu on synthetic imogolite. When adsorption occurs in the presence of cations with the exception of K(+), the kinetics of the process is well described by the pseudo-first order model. On the other hand, when adsorption is conducted in the presence of K(+), the adsorption kinetics is well described by the pseudo-second order, Elovich, and Weber-Morris models. From the surface charge measurements, the affinity between imogolite and the cations and their effect on the adsorption of trace elements, namely Cu and Cd, were established. Copyright © 2015 Elsevier B.V. All rights reserved.

Electrolyte and Plasma Changes After Ingestion of Pickle Juice, Water, and a Common Carbohydrate-Electrolyte Solution

PubMed Central

Miller, Kevin C.; Mack, Gary; Knight, Kenneth L.

2009-01-01

Abstract Context: Health care professionals advocate that athletes who are susceptible to exercise-associated muscle cramps (EAMCs) should moderately increase their fluid and electrolyte intake by drinking sport drinks. Some clinicians have also claimed drinking small volumes of pickle juice effectively relieves acute EAMCs, often alleviating them within 35 seconds. Others fear ingesting pickle juice will enhance dehydration-induced hypertonicity, thereby prolonging dehydration. Objective: To determine if ingesting small quantities of pickle juice, a carbohydrate-electrolyte (CHO-e) drink, or water increases plasma electrolytes or other selected plasma variables. Design: Crossover study. Setting: Exercise physiology laboratory. Patients or Other Participants: Nine euhydrated, healthy men (age  =  25 ± 2 years, height  =  179.4 ± 7.2 cm, mass  =  86.3 ± 15.9 kg) completed the study. Intervention(s): Resting blood samples were collected preingestion (−0.5 minutes); immediately postingestion (0 minutes); and at 1, 5, 10, 15, 20, 25, 30, 45, and 60 minutes postingestion of 1 mL/kg body mass of pickle juice, CHO-e drink, or tap water. Main Outcome Measure(s): Plasma sodium concentration, plasma magnesium concentration, plasma calcium concentration, plasma potassium concentration, plasma osmolality, and changes in plasma volume were analyzed. Urine specific gravity, osmolality, and volume were also measured to characterize hydration status. Results: Mean fluid intake was 86.3 ± 16.7 mL. Plasma sodium concentration, plasma magnesium concentration, plasma calcium concentration, plasma osmolality, and plasma volume did not change during the 60 minutes after ingestion of each fluid (P ≥ .05). Water ingestion slightly decreased plasma potassium concentration at 60 minutes (0.21 ± 0.14 mg/dL [0.21 ± 0.14 mmol/L]; P ≤ .05). Conclusions: At these volumes, ingestion of pickle juice and CHO-e drink did not cause substantial changes in plasma electrolyte

High-Performance Cells Containing Lithium Metal Anodes, LiNi0.6Co0.2Mn0.2O2 (NCM 622) Cathodes, and Fluoroethylene Carbonate-Based Electrolyte Solution with Practical Loading.

PubMed

Salitra, Gregory; Markevich, Elena; Afri, Michal; Talyosef, Yosef; Hartmann, Pascal; Kulisch, Joern; Sun, Yang-Kook; Aurbach, Doron

2018-06-13

We report on the highly stable lithium metal|LiNi 0.6 Co 0.2 Mn 0.2 O 2 (NCM 622) cells with practical electrodes' loading of 3.3 mA h g -1 , which can undergo many hundreds of stable cycles, demonstrating high rate capability. A key issue was the use of fluoroethylene carbonate (FEC)-based electrolyte solutions (1 M LiPF 6 in FEC/dimethyl carbonate). Li|NCM 622 cells can be cycled at 1.5 mA cm -2 for more than 600 cycles, whereas symmetric Li|Li cells demonstrate stable performance for more than 1000 cycles even at higher areal capacity and current density. We attribute the excellent performance of both Li|NCM and Li|Li cells to the formation of a stable and efficient solid electrolyte interphase (SEI) on the surface of the Li metal electrodes cycled in FEC-based electrolyte solutions. The composition of the SEI on the Li and the NCM electrodes is analyzed by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. A drastic capacity fading of Li|NCM cells is observed, followed by spontaneous capacity recovery during prolonged cycling. This phenomenon depends on the current density and the amount of the electrolyte solution and relates to kinetic limitations because of SEI formation on the Li anodes in the FEC-based electrolyte solution.

Simple electrolyte solutions: Comparison of DRISM and molecular dynamics results for alkali halide solutions

PubMed Central

Joung, In Suk; Luchko, Tyler; Case, David A.

2013-01-01

Using the dielectrically consistent reference interaction site model (DRISM) of molecular solvation, we have calculated structural and thermodynamic information of alkali-halide salts in aqueous solution, as a function of salt concentration. The impact of varying the closure relation used with DRISM is investigated using the partial series expansion of order-n (PSE-n) family of closures, which includes the commonly used hypernetted-chain equation (HNC) and Kovalenko-Hirata closures. Results are compared to explicit molecular dynamics (MD) simulations, using the same force fields, and to experiment. The mean activity coefficients of ions predicted by DRISM agree well with experimental values at concentrations below 0.5 m, especially when using the HNC closure. As individual ion activities (and the corresponding solvation free energies) are not known from experiment, only DRISM and MD results are directly compared and found to have reasonably good agreement. The activity of water directly estimated from DRISM is nearly consistent with values derived from the DRISM ion activities and the Gibbs-Duhem equation, but the changes in the computed pressure as a function of salt concentration dominate these comparisons. Good agreement with experiment is obtained if these pressure changes are ignored. Radial distribution functions of NaCl solution at three concentrations were compared between DRISM and MD simulations. DRISM shows comparable water distribution around the cation, but water structures around the anion deviate from the MD results; this may also be related to the high pressure of the system. Despite some problems, DRISM-PSE-n is an effective tool for investigating thermodynamic properties of simple electrolytes. PMID:23387564

The Electrostatic Screening Length in Concentrated Electrolytes Increases with Concentration.

PubMed

Smith, Alexander M; Lee, Alpha A; Perkin, Susan

2016-06-16

According to classical electrolyte theories interactions in dilute (low ion density) electrolytes decay exponentially with distance, with the Debye screening length the characteristic length scale. This decay length decreases monotonically with increasing ion concentration due to effective screening of charges over short distances. Thus, within the Debye model no long-range forces are expected in concentrated electrolytes. Here we reveal, using experimental detection of the interaction between two planar charged surfaces across a wide range of electrolytes, that beyond the dilute (Debye-Hückel) regime the screening length increases with increasing concentration. The screening lengths for all electrolytes studied-including aqueous NaCl solutions, ionic liquids diluted with propylene carbonate, and pure ionic liquids-collapse onto a single curve when scaled by the dielectric constant. This nonmonotonic variation of the screening length with concentration, and its generality across ionic liquids and aqueous salt solutions, demonstrates an important characteristic of concentrated electrolytes of substantial relevance from biology to energy storage.

Intravenous hypertonic saline solution (7.5%) and oral electrolytes to treat of calves with noninfectious diarrhea and metabolic acidosis.

PubMed

Leal, M L R; Fialho, S S; Cyrillo, F C; Bertagnon, H G; Ortolani, E L; Benesi, F J

2012-01-01

The aim of this study was to compare the efficacy of treating osmotic diarrhea and dehydration in calves with hypertonic saline solution (HSS) IV, isotonic electrolyte solution (IES) PO, and a combination of these 2 solutions (HSS + IES). Eighteen male calves 8-30 days of age were used to evaluate the efficacy of 3 methods of fluid therapy after induction of osmotic diarrhea and dehydration. The diarrhea and dehydration were induced by administration of saccharose, spironolactone, and hydrochlorothiazide for 48 hours. The animals were randomly divided into 3 experimental groups: Group 1: 7.2% hypertonic saline solution-HSS (5 mL/kg IV); Group 2: oral isotonic electrolyte solution IES (60 mL/kg PO); or Group 3: HSS+IES. Clinical signs and laboratory finding observed 48 hours post-induction (Time 0) included diarrhea, dehydration, lethargy, and metabolic acidosis. Calves treated with HSS + IES experienced decreases in hematocrit, total protein concentration, albumin concentration, urea nitrogen concentration, and plasma volume as well as increases in blood pH, blood bicarbonate concentration, and central venous pressure between 1 and 3 hours post-treatment. These findings also were observed in animals treated with IES, however, at a slower rate than in the HSS + IES-treated animals. Animals treated with HSS continued to display signs of dehydration, lethargy, and metabolic acidosis 24 hours post-treatment. Treatment with a combination of HSS and IES produced rapid and sustainable correction of hypovolemia and metabolic acidosis in calves with noninfections diarrhea and dehydration. Copyright © 2012 by the American College of Veterinary Internal Medicine.

Method of preparing electrolyte for use in fuel cells

DOEpatents

Kinoshita, Kimio; Ackerman, John P.

1978-01-01

An electrolyte compact for fuel cells includes a particulate support material of lithium aluminate that contains a mixture of alkali metal compounds, such as carbonates or hydroxides, as the active electrolyte material. The porous lithium aluminate support structure is formed by mixing alumina particles with a solution of lithium hydroxide and another alkali metal hydroxide, evaporating the solvent from the solution and heating to a temperature sufficient to react the lithium hydroxide with alumina to form lithium aluminate. Carbonates are formed by reacting the alkali metal hydroxides with carbon dioxide gas in an exothermic reaction which may proceed simultaneously with the formation with the lithium aluminate. The mixture of lithium aluminate and alkali metal in an electrolyte active material is pressed or otherwise processed to form the electrolyte structure for assembly into a fuel cell.

Composition and particle size of electrolytic copper powders prepared in water-containing dimethyl sulfoxide electrolytes

NASA Astrophysics Data System (ADS)

Mamyrbekova, Aigul'; Abzhalov, B. S.; Mamyrbekova, Aizhan

2017-07-01

The possibility of the electroprecipitation of copper powder via the cathodic reduction of an electrolyte solution containing copper(II) nitrate trihydrate and dimethyl sulfoxide (DMSO) is shown. The effect electrolysis conditions (current density, concentration and temperature of electrolyte) have on the dimensional characteristics of copper powder is studied. The size and shape of the particles of the powders were determined by means of electron microscopy; the qualitative composition of the powders, with X-ray diffraction.

Interaction between like-charged polyelectrolyte-colloid complexes in electrolyte solutions: a Monte Carlo simulation study in the Debye-Hückel approximation.

PubMed

Truzzolillo, D; Bordi, F; Sciortino, F; Sennato, S

2010-07-14

We study the effective interaction between differently charged polyelectrolyte-colloid complexes in electrolyte solutions via Monte Carlo simulations. These complexes are formed when short and flexible polyelectrolyte chains adsorb onto oppositely charged colloidal spheres, dispersed in an electrolyte solution. In our simulations the bending energy between adjacent monomers is small compared to the electrostatic energy, and the chains, once adsorbed, do not exchange with the solution, although they rearrange on the particles surface to accommodate further adsorbing chains or due to the electrostatic interaction with neighbor complexes. Rather unexpectedly, when two interacting particles approach each other, the rearrangement of the surface charge distribution invariably produces antiparallel dipolar doublets that invert their orientation at the isoelectric point. These findings clearly rule out a contribution of dipole-dipole interactions to the observed attractive interaction between the complexes, pointing out that such suspensions cannot be considered dipolar fluids. On varying the ionic strength of the electrolyte, we find that a screening length kappa(-1), short compared with the size of the colloidal particles, is required in order to observe the attraction between like-charged complexes due to the nonuniform distribution of the electric charge on their surface ("patch attraction"). On the other hand, by changing the polyelectrolyte/particle charge ratio xi(s), the interaction between like-charged polyelectrolyte-decorated particles, at short separations, evolves from purely repulsive to strongly attractive. Hence, the effective interaction between the complexes is characterized by a potential barrier, whose height depends on the net charge and on the nonuniformity of their surface charge distribution.

Recent results on aqueous electrolyte cells

NASA Astrophysics Data System (ADS)

Wessells, Colin; Huggins, Robert A.; Cui, Yi

2011-03-01

The improved safety of aqueous electrolytes makes aqueous lithium-ion batteries an attractive alternative to commercial cells utilizing flammable and expensive organic electrolytes. Two important issues relating to their use have been addressed in this work. One is the extension of the usable voltage range by the incorporation of lithium salts, and the other is the investigation of a useful negative electrode reactant, LiTi2(PO4)3. The electrochemical stability of aqueous lithium salt solutions containing two lithium salts, LiNO3 and Li2SO4, has been characterized using a constant current technique. In both cases, concentrated solutions had effective electrolyte stability windows substantially greater than that of pure water under standard conditions. At an electrolyte leakage current of 10 μA cm-2 between two platinum electrodes in 5 M LiNO3 the cell voltage can reach 2.0 V, whereas with a leakage current of 50 μA cm-2 it can reach 2.3 V. LiTi2(PO4)3 was synthesized using a Pechini method and cycled in pH-neutral Li2SO4. At a reaction potential near the lower limit of electrolyte stability, an initial discharge capacity of 118 mAh g-1 was measured at a C/5 rate, while about 90% of this discharge capacity was retained after 100 cycles. This work demonstrates that it is possible to have useful aqueous electrolyte lithium-ion batteries using the LiTi2(PO4)3 anode with cell voltages of 2 V and above.

Methods and energy storage devices utilizing electrolytes having surface-smoothing additives

DOEpatents

Xu, Wu; Zhang, Jiguang; Graff, Gordon L; Chen, Xilin; Ding, Fei

2015-11-12

Electrodeposition and energy storage devices utilizing an electrolyte having a surface-smoothing additive can result in self-healing, instead of self-amplification, of initial protuberant tips that give rise to roughness and/or dendrite formation on the substrate and anode surface. For electrodeposition of a first metal (M1) on a substrate or anode from one or more cations of M1 in an electrolyte solution, the electrolyte solution is characterized by a surface-smoothing additive containing cations of a second metal (M2), wherein cations of M2 have an effective electrochemical reduction potential in the solution lower than that of the cations of M1.

Graphene-oxide stabilization in electrolyte solutions using hydroxyethyl cellulose for drug delivery application.

PubMed

Mianehrow, Hanieh; Moghadam, Mohamad Hasan Mohamadzadeh; Sharif, Farhad; Mazinani, Saeedeh

2015-04-30

Stabilization of graphene oxide (GO) in physiological solution is performed using hydroxyethyl cellulose (HEC) to make the resultant nanohybrid suitable for targeted drug delivery purposes. Short and long term stability of GO suspensions with different ionic strengths were assessed using ultraviolet-visible spectroscopy (UV-vis), atomic force microscopy (AFM) and zeta potential measurements. Results depicted that HEC effectively stabilized GO in electrolyte solutions and the mechanism of stabilization appeares to be depended on HEC content. Drug loading and release behavior of folic acid (FA) as a model drug, from GO-HEC nanohybrid were studied to assess its application in drug delivery systems. Results showed the nanohybrid could be highly loaded by folic acid. Moreover, HEC content in the nanohybrid played an important role in final application to make it applicable either as a carrier for controllable drug release or as a folate-targeted drug carrier. In addition, according to cytotoxicity results, the nanohybrid showed good biocompatibility which indeed confirms its potential application as a drug carrier. Copyright © 2015 Elsevier B.V. All rights reserved.

Evaluating Transport Properties and Ionic Dissociation of LiPF 6 in Concentrated Electrolyte

DOE PAGES

Feng, Zhange; Higa, Kenneth; Han, Kee Sung; ...

2017-08-17

The presence of lithium hexafluorophosphate (LiPF 6) ion pairs in carbonate-based electrolyte solutions is widely accepted in the field of battery electrolyte research and is expected to affect solution transport properties. No existing techniques are capable of directly quantifying salt dissociation in these solutions. Previous publications by others have provided estimates of dissociation degrees using dilute solution theory and pulsed field gradient nuclear magnetic resonance spectroscopy (PFG-NMR) measurements of self-diffusivity. However, the behavior of a concentrated electrolyte solution can deviate significantly from dilute solution theory predictions. This paper, for the first time, instead uses Onsager–Stefan–Maxwell concentrated solution theory and themore » generalized Darken relation with PFG-NMR measurements to quantify the degrees of dissociation in electrolyte solutions (LiPF 6 in ethylene carbonate/diethyl carbonate, 1:1 by weight). At LiPF 6 concentrations ranging from 0.1 M to 1.5 M, the salt dissociation degree is found to range from 61% to 37%. Finally, transport properties are then calculated through concentrated solution theory with corrections for these significant levels of ion pairing.« less

Evaluating Transport Properties and Ionic Dissociation of LiPF 6 in Concentrated Electrolyte

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feng, Zhange; Higa, Kenneth; Han, Kee Sung

2017-01-01

The presence of lithium hexafluorophosphate (LiPF6) ion pairs in carbonate-based electrolyte solutions is widely accepted in the field of battery electrolyte research and is expected to affect solution transport properties. No existing techniques are capable of directly quantifying salt dissociation in these solutions. Previous publications by others have provided estimates of dissociation degrees using dilute solution theory and pulsed field gradient nuclear magnetic resonance spectroscopy (PFG-NMR) measurements of self-diffusivity. However, the behavior of a concentrated electrolyte solution can deviate significantly from dilute solution theory predictions. This work, for the first time, instead uses Onsager–Stefan–Maxwell concentrated solution theory and the generalized.more » Darken relation with PFG-NMR measurements to quantify the degrees of dissociation in electrolyte solutions (LiPF6 in ethylene carbonate/diethyl carbonate, 1:1 by weight). At LiPF6 concentrations ranging from 0.1 M to 1.5 M, the salt dissociation degree is found to range from 61% to 37%. Transport properties are then calculated through concentrated solution theory with corrections for these significant levels of ion pairing.« less

Independence of the effective dielectric constant of an electrolytic solution on the ionic distribution in the linear Poisson-Nernst-Planck model.

PubMed

Alexe-Ionescu, A L; Barbero, G; Lelidis, I

2014-08-28

We consider the influence of the spatial dependence of the ions distribution on the effective dielectric constant of an electrolytic solution. We show that in the linear version of the Poisson-Nernst-Planck model, the effective dielectric constant of the solution has to be considered independent of any ionic distribution induced by the external field. This result follows from the fact that, in the linear approximation of the Poisson-Nernst-Planck model, the redistribution of the ions in the solvent due to the external field gives rise to a variation of the dielectric constant that is of the first order in the effective potential, and therefore it has to be neglected in the Poisson's equation that relates the actual electric potential across the electrolytic cell to the bulk density of ions. The analysis is performed in the case where the electrodes are perfectly blocking and the adsorption at the electrodes is negligible, and in the absence of any ion dissociation-recombination effect.

A sealed optical cell for the study of lithium-electrode|electrolyte interfaces

NASA Astrophysics Data System (ADS)

Howlett, P. C.; MacFarlane, D. R.; Hollenkamp, A. F.

A sealed, symmetrical, lithium optical cell, which enables optical images of lithium surface deposits and in situ Raman spectra to be obtained simply and conveniently during charge-discharge cycling of lithium metal electrodes, has been designed and tested. A conventional aprotic liquid, 1 M lithium hexafluorophosphate in propylene carbonate, and an experimental ionic liquid, 20 mol% lithium bis(trifluoromethanesulfonyl)amide in 1-ethyl 3-methyl imidazolium bis(trifluoromethanesulfonyl)amide, are investigated as electrolyte solutions. Images obtained from the cell with the former electrolyte solution demonstrate the problems associated with cycling lithium metal electrodes. Images obtained with the latter electrolyte solution provide clear evidence that continued investigation of ionic liquids for use with lithium metal electrodes is warranted. Operation of the cell with the conventional electrolyte yields Raman spectra of good quality. The spectra display vibrational modes which arise from the electrolyte, as well as several additional modes which are associated with the deposits formed during cycling.

Conductivity of gel polymer electrolytes doped with solutions of phosphonic acid or protic ionic liquids

NASA Astrophysics Data System (ADS)

Shmukler, Liudmila E.; Fadeeva, Yuliya A.; Glushenkova, Ekaterina V.; Nguyen, Van Thuc; Safonova, Liubov P.

2018-04-01

The proton-conducting gel electrolytes (PCGEs) based on PMMA, PVdF or PVdF-HFP doped with solutions of phosphonic acid or ammonium based protic ionic liquids (PILs) in DMF have been synthesized. Rather high values of the conductivity (10-4-10-3 S cm-1) have been reached at low dopant concentrations (up to 1 mol l-1). The influence of the nature of both polymeric matrix and dopant as well as dopant concentration on the conductivity values was discussed. It was established that the dependence of conductivity on the nature of dopant, but not the polymeric matrix, was more pronounced.

Ionic liquids behave as dilute electrolyte solutions

PubMed Central

Gebbie, Matthew A.; Valtiner, Markus; Banquy, Xavier; Fox, Eric T.; Henderson, Wesley A.; Israelachvili, Jacob N.

2013-01-01

We combine direct surface force measurements with thermodynamic arguments to demonstrate that pure ionic liquids are expected to behave as dilute weak electrolyte solutions, with typical effective dissociated ion concentrations of less than 0.1% at room temperature. We performed equilibrium force–distance measurements across the common ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C4mim][NTf2]) using a surface forces apparatus with in situ electrochemical control and quantitatively modeled these measurements using the van der Waals and electrostatic double-layer forces of the Derjaguin–Landau–Verwey–Overbeek theory with an additive repulsive steric (entropic) ion–surface binding force. Our results indicate that ionic liquids screen charged surfaces through the formation of both bound (Stern) and diffuse electric double layers, where the diffuse double layer is comprised of effectively dissociated ionic liquid ions. Additionally, we used the energetics of thermally dissociating ions in a dielectric medium to quantitatively predict the equilibrium for the effective dissociation reaction of [C4mim][NTf2] ions, in excellent agreement with the measured Debye length. Our results clearly demonstrate that, outside of the bound double layer, most of the ions in [C4mim][NTf2] are not effectively dissociated and thus do not contribute to electrostatic screening. We also provide a general, molecular-scale framework for designing ionic liquids with significantly increased dissociated charge densities via judiciously balancing ion pair interactions with bulk dielectric properties. Our results clear up several inconsistencies that have hampered scientific progress in this important area and guide the rational design of unique, high–free-ion density ionic liquids and ionic liquid blends. PMID:23716690

Osmotic diuresis-induced hypernatremia: better explained by solute-free water clearance or electrolyte-free water clearance?

PubMed

Popli, Subhash; Tzamaloukas, Antonios H; Ing, Todd S

2014-01-01

Hypernatremia may result from inadequate water intake, excessive water loss or a combination of the two. Osmotic diuresis leads to losses of both solute and water. The relationship between solute and water losses determines the resulting changes in serum osmolality and sodium concentration. Total solute loss is routinely higher than loss of water in osmotic diuresis. Theoretically, then, decreases in serum osmolality (and serum sodium concentration) should follow. In clinical situations of osmotic diuresis, however, reduction in osmolality can take place, but not reduction in serum sodium concentration. It is of note that serum sodium concentration changes are related to urinary losses of sodium and potassium but not to the loss of total solute. In osmotic diuresis, the combined loss of sodium and potassium per liter of urine is lower than the concurrent serum sodium level. Consequently, hypernatremia can ensue. A patient who presented with osmotic diuresis and hypernatremia is described here. In this patient, we have shown that electrolyte-free water clearance is a better index of the effect of osmotic diuresis on serum sodium concentration than the classic solute-free water clearance.

Molecular interactions in high conductive gel electrolytes based on low molecular weight gelator.

PubMed

Bielejewski, Michał; Łapiński, Andrzej; Demchuk, Oleg

2017-03-15

Organic ionic gel (OIG) electrolytes, also known as gel electrolytes or ionogels are one example of modern functional materials with the potential to use in wide range of electrochemical applications. The functionality of OIGs arises from the thermally reversible solidification of electrolytes or ionic liquids and their superior ionic conductivity. To understand and to predict the properties of these systems it is important to get the knowledge about the interactions on molecular level between the solid gelator matrix and the electrolyte solution. This paper reports the spectroscopic studies (FT-IR, UV-Vis and Raman) of the gel electrolyte based on low molecular weight gelator methyl-4,6-O-(p-nitrobenzylidene)-α-d-glucopyranoside and solution of quaternary ammonium salt, tetramethylammonium bromide. The solidification process was based on sol-gel technique. Below characteristic temperature, defined as gel to sol phase transition temperature, T gs , the samples were solid-like and showed high conductivity values of the same order as observed for pure liquid electrolytes. The investigations were performed for a OIGs in a wide range of molar concentrations of the electrolyte solution. Copyright © 2016 Elsevier Inc. All rights reserved.

Sulfone-based electrolytes for aluminium rechargeable batteries.

PubMed

Nakayama, Yuri; Senda, Yui; Kawasaki, Hideki; Koshitani, Naoki; Hosoi, Shizuka; Kudo, Yoshihiro; Morioka, Hiroyuki; Nagamine, Masayuki

2015-02-28

Electrolyte is a key material for success in the research and development of next-generation rechargeable batteries. Aluminium rechargeable batteries that use aluminium (Al) metals as anode materials are attractive candidates for next-generation batteries, though they have not been developed yet due to the lack of practically useful electrolytes. Here we present, for the first time, non-corrosive reversible Al electrolytes working at room temperature. The electrolytes are composed of aluminium chlorides, dialkylsulfones, and dilutants, which are realized by the identification of electrochemically active Al species, the study of sulfone dependences, the effects of aluminium chloride concentrations, dilutions and their optimizations. The characteristic feature of these materials is the lower chloride concentrations in the solutions than those in the conventional Al electrolytes, which allows us to use the Al metal anodes without corrosions. We anticipate that the sulfone-based electrolytes will open the doors for the research and development of Al rechargeable batteries.

Selection of new Kynar-based electrolytes for lithium-ion batteries

NASA Astrophysics Data System (ADS)

Christie, Alasdair M.; Christie, Lynn; Vincent, Colin A.

New electrolyte solution compositions have been identified for use in lithium-ion batteries after gelling with an appropriate quantity of Kynar polymer. Since the Li + conducting medium is largely the liquid electrolyte component, the assessment of these solutions as suitable lithium-ion cell candidates were investigated before adding the polymer. Selected electrolyte solutions were then used in the preparation of polymer gels. The specific conductivities of Kynar-based gels were determined as a function of salt concentration and polymer concentration. Optimised self-supporting polymer films, based on mixtures of ethylene carbonate (EC), ethylmethyl carbonate (EMC) and lithium hexafluorophosphate (LiPF 6) or lithium tetrafluoroborate (LiBF 4), showed good high current density cycling performance when used as separators in coke and Li 1- xMn 2O 4 (spinel) half-cells.

Obtaining accurate amounts of mercury from mercury compounds via electrolytic methods

DOEpatents

Grossman, Mark W.; George, William A.

1987-01-01

A process for obtaining pre-determined, accurate rate amounts of mercury. In one embodiment, predetermined, precise amounts of Hg are separated from HgO and plated onto a cathode wire. The method for doing this involves dissolving a precise amount of HgO which corresponds to a pre-determined amount of Hg desired in an electrolyte solution comprised of glacial acetic acid and H.sub.2 O. The mercuric ions are then electrolytically reduced and plated onto a cathode producing the required pre-determined quantity of Hg. In another embodiment, pre-determined, precise amounts of Hg are obtained from Hg.sub.2 Cl.sub.2. The method for doing this involves dissolving a precise amount of Hg.sub.2 Cl.sub.2 in an electrolyte solution comprised of concentrated HCl and H.sub.2 O. The mercurous ions in solution are then electrolytically reduced and plated onto a cathode wire producing the required, pre-determined quantity of Hg.

Obtaining accurate amounts of mercury from mercury compounds via electrolytic methods

DOEpatents

Grossman, M.W.; George, W.A.

1987-07-07

A process is described for obtaining pre-determined, accurate rate amounts of mercury. In one embodiment, predetermined, precise amounts of Hg are separated from HgO and plated onto a cathode wire. The method for doing this involves dissolving a precise amount of HgO which corresponds to a pre-determined amount of Hg desired in an electrolyte solution comprised of glacial acetic acid and H[sub 2]O. The mercuric ions are then electrolytically reduced and plated onto a cathode producing the required pre-determined quantity of Hg. In another embodiment, pre-determined, precise amounts of Hg are obtained from Hg[sub 2]Cl[sub 2]. The method for doing this involves dissolving a precise amount of Hg[sub 2]Cl[sub 2] in an electrolyte solution comprised of concentrated HCl and H[sub 2]O. The mercurous ions in solution are then electrolytically reduced and plated onto a cathode wire producing the required, pre-determined quantity of Hg. 1 fig.

Method of synthesizing polymers from a solid electrolyte

DOEpatents

Skotheim, Terje A.

1985-01-01

A method of synthesizing electrically conductive polymers from a solvent-free solid polymer electrolyte wherein an assembly of a substrate having an electrode thereon, a thin coating of solid electrolyte including a solution of PEO complexed with an alkali salt, and a thin transparent noble metal electrode are disposed in an evacuated chamber into which a selected monomer vapor is introduced while an electric potential is applied across the solid electrolyte to hold the thin transparent electrode at a positive potential relative to the electrode on the substrate, whereby a highly conductive polymer film is grown on the transparent electrode between it and the solid electrolyte.

Method of synthesizing polymers from a solid electrolyte

DOEpatents

Skotheim, T.A.

1984-10-19

A method of synthesizing electrically conductive polymers from a solvent-free solid polymer electrolyte is disclosed. An assembly of a substrate having an electrode thereon, a thin coating of solid electrolyte including a solution of PEO complexed with an alkali salt, and a thin transparent noble metal electrode are disposed in an evacuated chamber into which a selected monomer vapor is introduced while an electric potential is applied across the solid electrolyte to hold the thin transparent electrode at a positive potential relative to the electrode on the substrate, whereby a highly conductive polymer film is grown on the transparent electrode between it and the solid electrolyte.

Process for electrolytic deposition of metals on zirconium materials

DOEpatents

Donaghy, Robert E.

1979-01-30

A process for the electrolytic deposition of a metal layer on an article comprised of zirconium or a zirconium alloy is disclosed. The article is activated in an aged aqueous solution comprising from about 10 to about 20 grams per liter ammonium bifluoride and from about 0.75 to about 2 grams per liter of sulfuric acid. The solution is aged by immersion of pickled zirconium in the solution for at least about 10 minutes. The loosely adhering film formed on the article in the activating step is removed and the article is contacted with an electrolytic plating solution containing the metal to be deposited on the article in the presence of an electrode receiving current.

The impact of electrolyte on the adsorption of the anionic surfactant methyl ester sulfonate at the air-solution interface: Surface multilayer formation.

PubMed

Xu, H; Thomas, R K; Penfold, J; Li, P X; Ma, K; Welbourne, R J L; Roberts, D W; Petkov, J T

2018-02-15

The methyl ester sulfonates represent a promising group of anionic surfactants which have the potential for improved performance and biocompatibility in a range of applications. Their solution properties, in particular their tolerance to hard water, suggests that surface ordering may occur in the presence of multi-valent counterion. Understanding their adsorption properties in a range of different circumstances is key to the exploitation of their potential. Neutron reflectivity and surface tension have been used to characterise the adsorption at the air-aqueous solution interface of the anionic surfactant sodium tetradecanoic 2-sulfo 1-methyl ester, C 14 MES, in the absence of electrolyte and in the presence of mono, di, and tri-valent counterions, Na + , Ca 2+ , and Al 3+ . In particular the emphasis has been on exploring the tendency to form layered structures at the interface. In the absence of electrolyte and in the presence of NaCl and CaCl 2 and AlCl 3 at low concentrations monolayer adsorption is observed, and the addition of electrolyte results in enhanced adsorption. In the presence of NaCl and CaCl 2 only monolayer adsorption is observed. However at higher AlCl 3 concentrations surface multilayer formation is observed, in which the number of bilayers at the surface depends upon the surfactant and AlCl 3 concentrations. Copyright © 2017 Elsevier Inc. All rights reserved.

Surface-charge-governed electrolyte transport in carbon nanotubes

NASA Astrophysics Data System (ADS)

Xue, Jian-Ming; Guo, Peng; Sheng, Qian

2015-08-01

The transport behavior of pressure-driven aqueous electrolyte solution through charged carbon nanotubes (CNTs) is studied by using molecular dynamics simulations. The results reveal that the presence of charges around the nanotube can remarkably reduce the flow velocity as well as the slip length of the aqueous solution, and the decreasing of magnitude depends on the number of surface charges and distribution. With 1-M KCl solution inside the carbon nanotube, the slip length decreases from 110 nm to only 14 nm when the number of surface charges increases from 0 to 12 e. This phenomenon is attributed to the increase of the solid-liquid friction force due to the electrostatic interaction between the charges and the electrolyte particles, which can impede the transports of water molecules and electrolyte ions. With the simulation results, we estimate the energy conversion efficiency of nanofluidic battery based on CNTs, and find that the highest efficiency is only around 30% but not 60% as expected in previous work. Project supported by the National Natural Science Foundation of China (Grant Nos. 11375031 and 11335003).

[Rice water with and without electrolytes in diarrhea with a high stool output].

PubMed

Mota-Hernández, F; Posadas-Tello, N M; Rodríguez-Leyva, G

1993-12-01

The objective of the study was to determine the efficacy and safety of two rice-based oral rehydration solutions, with and without added electrolyte in children presenting acute diarrheal dehydration with high stool output (> 10 mL/kg/h) during a two-hour rehydration period. Twenty-two patients of one to 18 months old were recruited and randomly distributed into two groups: group A received the rice-based solution without electrolytes, and group B received the rice-based solution with electrolytes. A stool output diminishing was observed in both groups and rehydration was achieved in 4.0 +/- 0.9 hours in 21 patients from group A and in 4.6 +/- 0.9 hours in 13 patients group group B. There was not a statistically significant difference between the groups regarding the laboratory results. The rice-based oral rehydration solution without added electrolytes was useful for rehydration of children presenting high stool output, after administering the WHO/ORS recommended formula during a two-hour period.

Stabilizing electrochemical interfaces in viscoelastic liquid electrolytes

PubMed Central

2018-01-01

Electrodeposition is a widely practiced method for creating metal, colloidal, and polymer coatings on conductive substrates. In the Newtonian liquid electrolytes typically used, the process is fundamentally unstable. The underlying instabilities have been linked to failure of microcircuits, dendrite formation on battery electrodes, and overlimiting conductance in ion-selective membranes. We report that viscoelastic electrolytes composed of semidilute solutions of very high–molecular weight neutral polymers suppress these instabilities by multiple mechanisms. The voltage window ΔV in which a liquid electrolyte can operate free of electroconvective instabilities is shown to be markedly extended in viscoelastic electrolytes and is a power-law function, ΔV : η1/4, of electrolyte viscosity, η. This power-law relation is replicated in the resistance to ion transport at liquid/solid interfaces. We discuss consequences of our observations and show that viscoelastic electrolytes enable stable electrodeposition of many metals, with the most profound effects observed for reactive metals, such as sodium and lithium. This finding is of contemporary interest for high-energy electrochemical energy storage. PMID:29582017

Theoretical analysis of aqueous solutions of mixed strong electrolytes by a smaller-ion shell electrostatic model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fraenkel, Dan, E-mail: dfraenkel@eltronresearch.com

2014-02-07

In spite of the great importance of mixed electrolytes in science and technology, no compelling theoretical explanation has been offered yet for the thermodynamic behavior of such systems, such as their deviation from ideality and the variation of their excess functions with ionic composition and concentration. Using the newly introduced Smaller-ion Shell treatment – an extension of the Debye–Hückel theory to ions of dissimilar size (hence DH–SiS) – simple analytic mathematical expressions can be derived for the mean and single-ion activity coefficients of binary electrolyte components of ternary ionic systems. Such expressions are based on modifying the parallel DH–SiS equationsmore » for pure binary ionic systems, by adding to the three ion-size parameters – a (of counterions), b{sub +} (of positive coions), and b{sub −} (of negative coions) – a fourth parameter. For the (+ + −) system, this is “b{sub ++},” the contact distance between non-coion cations. b{sub ++} is derived from fits with experiment and, like the other b’s, is constant at varying ion concentration and combination. Four case studies are presented: (1) HCl–NaCl–H{sub 2}O, (2) HCl–NH{sub 4}Cl–H{sub 2}O, (3) (0.01 M HX)–MX–H{sub 2}O with X = Cl, Br, and with M = Li, Na, K, Cs, and (4) HCl–MCl{sub n}–H{sub 2}O with n = 2, M = Sr, Ba; and n = 3, M = Al, Ce. In all cases, theory is fully consistent with experiment when using a of the measured binary electrolyte as the sole fitting parameter. DH–SiS is thus shown to explain known “mysteries” in the behavior of ternary electrolytes, including Harned rule, and to adequately predict the pH of acid solutions in which ionized salts are present at different concentrations.« less

Utilization of aloe vera extract as electrolyte for an accumulator

NASA Astrophysics Data System (ADS)

Azmi, F.; Sispriatna, D.; Ikhsan, K.; Masrura, M.; Azzahra, S. S.; Mahidin; Supardan, M. D.

2018-03-01

Aloe vera contains acid, which has the potential to generate electric current. The objective of this research is to study the potency of aloe vera extract as electrolyte for an accumulator. Experimental results showed that aloe vera extract has no a stable value of voltage and currency. The voltage and currency of aloe vera extract were reduced more than 50% for 60 minutes. Then, aloe vera extract was mixed with accu zuur to produce electrolyte solution. The mixture composition of aloe vera extract to accu zuur of 50:50 (v/v) generated stable voltage and currency. The experimental results showed the potential use of aloe vera extract to reduce the chemicals used in a conventional electrolyte solution.

Comparison of Polyethylene Glycol-Electrolyte Solution vs Polyethylene Glycol-3350 for the Treatment of Fecal Impaction in Pediatric Patients.

PubMed

Boles, Erin E; Gaines, Cameryn L; Tillman, Emma M

2015-01-01

The objective of this study was to evaluate the safety and efficacy of polyethylene glycol-electrolyte solution vs polyethylene glycol-3350 for the treatment of fecal impaction in pediatric patients. A retrospective, observational, institutional review board-approved study was conducted over a 1-year time period. Patients were included in the study if they were admitted to the hospital with a diagnosis of fecal impaction or constipation and were treated with either polyethylene glycol-electrolyte solution (PEG-ES) or polyethylene glycol-3350 (PEG-3350). Patients were excluded if they were discharged prior to resolution of treatment and/or did not receive PEG-ES or PEG-3350. Fifty-one patients (ranging in age from 1 month to 15 years) were evaluated: 23 patients received PEG-ES and 28 patients received PEG-3350. Sex, race, age, and weight were not statistically different between the 2 groups. Resolution of fecal impaction was not significantly different between PEG-ES vs PEG-3350 (87% and 86%, respectively; p = 0.87). There was only 1 reported side effect with PEG-3350, vs 11 reported side effects with PEG-ES (p < 0.01). Theses results suggest that PEG-3350 is as effective as PEG-ES for the treatment of fecal impaction in pediatric patients and is associated with fewer side effects.

A low-temperature electrolyte for lithium and lithium-ion batteries

NASA Astrophysics Data System (ADS)

Plichta, E. J.; Behl, W. K.

An electrolyte consisting of 1 M solution of lithium hexafluorophosphate in 1:1:1 ethylene carbonate(EC)-dimethyl carbonate(DMC)-ethyl methyl carbonate(EMC) is proposed for low temperature applications of lithium and lithium-ion cells. The new electrolyte has good conductivity and electrochemical stability. Lithium and lithium-ion cells using the new electrolyte were found to be operable at temperatures down to -40°C. The paper also reports on the electrochemical stability of aluminum metal, which is used as a substrate for the positive electrodes in lithium-ion cells, in the new electrolyte.

Theory of linear sweep voltammetry with diffuse charge: Unsupported electrolytes, thin films, and leaky membranes

NASA Astrophysics Data System (ADS)

Yan, David; Bazant, Martin Z.; Biesheuvel, P. M.; Pugh, Mary C.; Dawson, Francis P.

2017-03-01

Linear sweep and cyclic voltammetry techniques are important tools for electrochemists and have a variety of applications in engineering. Voltammetry has classically been treated with the Randles-Sevcik equation, which assumes an electroneutral supported electrolyte. In this paper, we provide a comprehensive mathematical theory of voltammetry in electrochemical cells with unsupported electrolytes and for other situations where diffuse charge effects play a role, and present analytical and simulated solutions of the time-dependent Poisson-Nernst-Planck equations with generalized Frumkin-Butler-Volmer boundary conditions for a 1:1 electrolyte and a simple reaction. Using these solutions, we construct theoretical and simulated current-voltage curves for liquid and solid thin films, membranes with fixed background charge, and cells with blocking electrodes. The full range of dimensionless parameters is considered, including the dimensionless Debye screening length (scaled to the electrode separation), Damkohler number (ratio of characteristic diffusion and reaction times), and dimensionless sweep rate (scaled to the thermal voltage per diffusion time). The analysis focuses on the coupling of Faradaic reactions and diffuse charge dynamics, although capacitive charging of the electrical double layers is also studied, for early time transients at reactive electrodes and for nonreactive blocking electrodes. Our work highlights cases where diffuse charge effects are important in the context of voltammetry, and illustrates which regimes can be approximated using simple analytical expressions and which require more careful consideration.

Multi-electrolyte-step anodic aluminum oxide method for the fabrication of self-organized nanochannel arrays

PubMed Central

2012-01-01

Nanochannel arrays were fabricated by the self-organized multi-electrolyte-step anodic aluminum oxide [AAO] method in this study. The anodization conditions used in the multi-electrolyte-step AAO method included a phosphoric acid solution as the electrolyte and an applied high voltage. There was a change in the phosphoric acid by the oxalic acid solution as the electrolyte and the applied low voltage. This method was used to produce self-organized nanochannel arrays with good regularity and circularity, meaning less power loss and processing time than with the multi-step AAO method. PMID:22333268

ELECTROLYTIC PRODUCTION OF URANIUM TETRAFLUORIDE

DOEpatents

Lofthouse, E.

1954-08-31

This patent relates to electrolytic methods for the production of uranium tetrafluoride. According to the present invention a process for the production of uranium tetrafluoride comprises submitting to electrolysis an aqueous solution of uranyl fluoride containing free hydrofluoric acid. Advantageously the aqueous solution of uranyl fluoride is obtained by dissolving uranium hexafluoride in water. On electrolysis, the uranyl ions are reduced to uranous tons at the cathode and immediately combine with the fluoride ions in solution to form the insoluble uranium tetrafluoride which is precipitated.

Exact solutions to force-free electrodynamics in black hole backgrounds

NASA Astrophysics Data System (ADS)

Brennan, T. Daniel; Gralla, Samuel E.; Jacobson, Ted

2013-10-01

A shared property of several of the known exact solutions to the equations of force-free electrodynamics is that their charge-current four-vector is null. We examine the general properties of null-current solutions and then focus on the principal congruences of the Kerr black hole spacetime. We obtain a large class of exact solutions, which are in general time-dependent and non-axisymmetric. These solutions include waves that, surprisingly, propagate without scattering on the curvature of the black hole’s background. They may be understood as generalizations to Robinson’s solutions to vacuum electrodynamics associated with a shear-free congruence of null geodesics. When stationary and axisymmetric, our solutions reduce to those of Menon and Dermer, the only previously known solutions in Kerr. In Kerr, all of our solutions have null electromagnetic fields (\\vec{E} \\cdot \\vec{B} = 0 and E2 = B2). However, in Schwarzschild or flat spacetime there is freedom to add a magnetic monopole field, making the solutions magnetically dominated (B2 > E2). This freedom may be used to reproduce the various flat-spacetime and Schwarzschild-spacetime (split) monopole solutions available in the literature (due to Michel and later authors), and to obtain a large class of time-dependent, non-axisymmetric generalizations. These generalizations may be used to model the magnetosphere of a conducting star that rotates with arbitrary prescribed time-dependent rotation axis and speed. We thus significantly enlarge the class of known exact solutions, while organizing and unifying previously discovered solutions in terms of their null structure.

ZnCl 2- and NH 4Cl-hydroponics gel electrolytes for zinc-carbon batteries

NASA Astrophysics Data System (ADS)

Khalid, N. H.; Ismail, Y. M. Baba; Mohamad, A. A.

Absorbency testing is used to determine the percentage of ZnCl 2 or NH 4Cl solution absorbed by a hydroponics gel (HPG). It is found that the absorbency of ZnCl 2 or NH 4Cl solution decreases with increasing solution concentration. The conductivity of ZnCl 2- and NH 4Cl-HPG electrolytes is dependent on the solution concentration. A mixture of salt solution with HPG yields excellent gel polymer electrolytes with conductivities of 0.026 and 0.104 S cm -1 at 3 M ZnCl 2 and 7 M NH 4Cl, respectively. These gel electrolytes are then used to produce zinc-carbon cells. The fabricated cells give capacities of 8.8 and 10.0 mAh, have an internal resistance of 25.4 and 19.8 Ω, a maximum power density of 12.7 and 12.2 mW cm -2, and a short-circuit current density of 29.1 and 33.9 mA cm -2 for ZnCl 2- and NH 4Cl-HPG electrolytes, respectively.

Ionic-Liquid-Based Polymer Electrolytes for Battery Applications.

PubMed

Osada, Irene; de Vries, Henrik; Scrosati, Bruno; Passerini, Stefano

2016-01-11

The advent of solid-state polymer electrolytes for application in lithium batteries took place more than four decades ago when the ability of polyethylene oxide (PEO) to dissolve suitable lithium salts was demonstrated. Since then, many modifications of this basic system have been proposed and tested, involving the addition of conventional, carbonate-based electrolytes, low molecular weight polymers, ceramic fillers, and others. This Review focuses on ternary polymer electrolytes, that is, ion-conducting systems consisting of a polymer incorporating two salts, one bearing the lithium cation and the other introducing additional anions capable of plasticizing the polymer chains. Assessing the state of the research field of solid-state, ternary polymer electrolytes, while giving background on the whole field of polymer electrolytes, this Review is expected to stimulate new thoughts and ideas on the challenges and opportunities of lithium-metal batteries. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Microchip electrophoresis with background electrolyte containing polyacrylic acid and high content organic solvent in cyclic olefin copolymer microchips for easily adsorbed dyes.

PubMed

Wei, Xuan; Sun, Ping; Yang, Shenghong; Zhao, Lei; Wu, Jing; Li, Fengyun; Pu, Qiaosheng

2016-07-29

Plastic microchips can significantly reduce the fabrication cost but the adsorption of some analytes limits their application. In this work, background electrolyte containing ionic polymer and high content of organic solvent was adopted to eliminate the analyte adsorption and achieve highly efficient separation in microchip electrophoresis. Two dyes, rhodamine 6G (Rh6G) and rhodamine B (RhB) were used as the model analytes. By using methanol as the organic solvent and polyacrylic acid (PAA) as a multifunctional additive, successful separation of the two dyes within 75μm id. microchannels was realized. The role of PAA is multiple, including viscosity regulator, selectivity modifier and active additive for counteracting analyte adsorption on the microchannel surface. The number of theoretical plate of 7.0×10(5)/m was attained within an effective separation distance of 2cm using background electrolyte consisting 80% methanol, 0.36% PAA and 30mmol/L phosphate at pH 5.0. Under optimized conditions, relative standard deviations of Rh6G and RhB detection (n=5) were no more than 1.5% for migration time and 2.0% for peak area, respectively. The limit of detection (S/N=3) was 0.1nmol/L for Rh6G. The proposed technique was applied in the determination of both Rh6G and RhB in chilli powder and lipstick samples with satisfactory recoveries of 81.3-103.7%. Copyright © 2016 Elsevier B.V. All rights reserved.

Characterization of a membrane-based, electrochemically driven pumping system using aqueous electrolyte solutions.

PubMed

Norman, Mya A; Evans, Christine E; Fuoco, Anthony R; Noble, Richard D; Koval, Carl A

2005-10-01

Electrokinetic flow provides a mechanism for a variety of fluid pumping schemes. The design and characterization of an electrochemically driven pump that utilizes porous carbon electrodes, iodide/triiodide redox electrolytes, and Nafion membranes is described. Fluid pumping by the cell is reversible and controlled by the cell current. Chronopotentiometry experiments indicate that the total available fluid that can be pumped in a single electrolysis without gas evolution is determined solely by the initial concentration of electrolyte and the applied current. The magnitude of the fluid flow at a given current is determined by the nature of the cation in the electrolyte and by the water absorption properties of the Nafion membrane. For 1 M aqueous electrolytes, pumping rates ranging from 1 to 14 microL/min were obtained for current densities of 10-30 mA/cm2 of membrane area. Molar volume changes for the I3-/I- redox couple and for the alkali cation migration contribute little to the observed volumetric flow rates; the magnitude of the flow is dominated by the migration-induced flow of water.

Temperature dependence of water-water and ion-water correlations in bulk water and electrolyte solutions probed by femtosecond elastic second harmonic scattering

NASA Astrophysics Data System (ADS)

Chen, Yixing; Dupertuis, Nathan; Okur, Halil I.; Roke, Sylvie

2018-06-01

The temperature dependence of the femtosecond elastic second harmonic scattering (fs-ESHS) response of bulk light and heavy water and their electrolyte solutions is presented. We observe clear temperature dependent changes in the hydrogen (H)-bond network of water that show a decrease in the orientational order of water with increasing temperature. Although D2O has a more structured H-bond network (giving rise to more fs-ESHS intensity), the relative temperature dependence is larger in H2O. The changes are interpreted in terms of the symmetry of H-bonds and are indicators of nuclear quantum effects. Increasing the temperature in electrolyte solutions decreases the influence of the total electrostatic field from ions on the water-water correlations, as expected from Debye-Hückel theory, since the Debye length becomes longer. The effects are, however, 1.9 times (6.3 times) larger than those predicted for H2O (D2O). Since fs-ESHS responses can be computed from known molecular coordinates, our observations provide a unique opportunity to refine quantum mechanical models of water.

Systems and methods for rebalancing redox flow battery electrolytes

DOEpatents

Pham, Ai Quoc; Chang, On Kok

2015-03-17

Various methods of rebalancing electrolytes in a redox flow battery system include various systems using a catalyzed hydrogen rebalance cell configured to minimize the risk of dissolved catalyst negatively affecting flow battery performance. Some systems described herein reduce the chance of catalyst contamination of RFB electrolytes by employing a mediator solution to eliminate direct contact between the catalyzed membrane and the RFB electrolyte. Other methods use a rebalance cell chemistry that maintains the catalyzed electrode at a potential low enough to prevent the catalyst from dissolving.

Lactulose vs Polyethylene Glycol 3350-Electrolyte Solution for Treatment of Overt Hepatic Encephalopathy

PubMed Central

Rahimi, Robert S.; Singal, Amit G.; Cuthbert, Jennifer A.; Rockey, Don C.

2017-01-01

IMPORTANCE Hepatic encephalopathy (HE) is a common cause of hospitalization in patients with cirrhosis. Pharmacologic treatment for acute (overt) HE has remained the same for decades. OBJECTIVE To compare polyethylene glycol 3350–electrolyte solution (PEG) and lactulose treatments in patients with cirrhosis admitted to the hospital for HE. We hypothesized that rapid catharsis of the gut using PEG may resolve HE more effectively than lactulose. DESIGN, SETTING, AND PARTICIPANTS The HELP (Hepatic Encephalopathy: Lactulose vs Polyethylene Glycol 3350-Electrolyte Solution) study is a randomized clinical trial in an academic tertiary hospital of 50 patients with cirrhosis (of 186 screened) admitted for HE. INTERVENTIONS Participants were block randomized to receive treatment with PEG, 4-L dose (n = 25), or standard-of-care lactulose (n = 25) during hospitalization. MAIN OUTCOMES AND MEASURES The primary end point was an improvement of 1 or more in HE grade at 24 hours, determined using the hepatic encephalopathy scoring algorithm (HESA), ranging from 0 (normal clinical and neuropsychological assessments) to 4 (coma). Secondary outcomes included time to HE resolution and overall length of stay. RESULTS A total of 25 patients were randomized to each treatment arm. Baseline clinical features at admission were similar in the groups. Thirteen of 25 patients in the standard therapy arm (52%) had an improvement of 1 or more in HESA score, thus meeting the primary outcome measure, compared with 21 of 23 evaluated patients receiving PEG (91%) (P < .01); 1 patient was discharged before final analysis and 1 refused participation. The mean (SD) HESA score at 24 hours for patients receiving standard therapy changed from 2.3 (0.9) to 1.6 (0.9) compared with a change from 2.3 (0.9) to 0.9 (1.0) for the PEG-treated groups (P = .002). The median time for HE resolution was 2 days for standard therapy and 1 day for PEG (P = .01). Adverse events were uncommon, and none was definitely

Acute Symptomatic Seizures Caused by Electrolyte Disturbances

PubMed Central

Nardone, Raffaele; Brigo, Francesco

2016-01-01

In this narrative review we focus on acute symptomatic seizures occurring in subjects with electrolyte disturbances. Quite surprisingly, despite its clinical relevance, this issue has received very little attention in the scientific literature. Electrolyte abnormalities are commonly encountered in clinical daily practice, and their diagnosis relies on routine laboratory findings. Acute and severe electrolyte imbalances can manifest with seizures, which may be the sole presenting symptom. Seizures are more frequently observed in patients with sodium disorders (especially hyponatremia), hypocalcemia, and hypomagnesemia. They do not entail a diagnosis of epilepsy, but are classified as acute symptomatic seizures. EEG has little specificity in differentiating between various electrolyte disturbances. The prominent EEG feature is slowing of the normal background activity, although other EEG findings, including various epileptiform abnormalities may occur. An accurate and prompt diagnosis should be established for a successful management of seizures, as rapid identification and correction of the underlying electrolyte disturbance (rather than an antiepileptic treatment) are of crucial importance in the control of seizures and prevention of permanent brain damage. PMID:26754778

Coatable Li4 SnS4 Solid Electrolytes Prepared from Aqueous Solutions for All-Solid-State Lithium-Ion Batteries.

PubMed

Choi, Young Eun; Park, Kern Ho; Kim, Dong Hyeon; Oh, Dae Yang; Kwak, Hi Ram; Lee, Young-Gi; Jung, Yoon Seok

2017-06-22

Bulk-type all-solid-state lithium-ion batteries (ASLBs) for large-scale energy-storage applications have emerged as a promising alternative to conventional lithium-ion batteries (LIBs) owing to their superior safety. However, the electrochemical performance of bulk-type ASLBs is critically limited by the low ionic conductivity of solid electrolytes (SEs) and poor ionic contact between the active materials and SEs. Herein, highly conductive (0.14 mS cm -1 ) and dry-air-stable SEs (Li 4 SnS 4 ) are reported, which are prepared using a scalable aqueous-solution process. An active material (LiCoO 2 ) coated by solidified Li 4 SnS 4 from aqueous solutions results in a significant improvement in the electrochemical performance of ASLBs. Side-effects of the exposure of LiCoO 2 to aqueous solutions are minimized by using predissolved Li 4 SnS 4 solution. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Oxide-based synaptic transistors gated by solution-processed gelatin electrolytes

NASA Astrophysics Data System (ADS)

He, Yinke; Sun, Jia; Qian, Chuan; Kong, Ling-An; Gou, Guangyang; Li, Hongjian

2017-04-01

In human brain, a large number of neurons are connected via synapses. Simulation of the synaptic behaviors using electronic devices is the most important step for neuromorphic systems. In this paper, proton conducting gelatin electrolyte-gated oxide field-effect transistors (FETs) were used for emulating synaptic functions, in which the gate electrode is regarded as pre-synaptic neuron and the channel layer as the post-synaptic neuron. In analogy to the biological synapse, a potential spike can be applied at the gate electrode and trigger ionic motion in the gelatin electrolyte, which in turn generates excitatory post-synaptic current (EPSC) in the channel layer. Basic synaptic behaviors including spike time-dependent EPSC, paired-pulse facilitation (PPF), self-adaptation, and frequency-dependent synaptic transmission were successfully mimicked. Such ionic/electronic hybrid devices are beneficial for synaptic electronics and brain-inspired neuromorphic systems.

Improved fabrication of electrolytic capacitors

NASA Technical Reports Server (NTRS)

Gamari, F. J.; Moresi, J. L.

1975-01-01

After processing parts for assembly, insulative cup is fitted to bottom of can, then electrolytic solution consisting of white sulfuric acid gel is inserted into can. Pellet is put in can and is fitted tightly into cup. Finally, bead weld is formed between can and header plug.

Equilibrium, Kinetics, and Spectroscopic Studies of SF6 Hydrate in NaCl Electrolyte Solution.

PubMed

Seo, Youngrok; Moon, Donghyun; Lee, Changho; Park, Jeong-Woo; Kim, Byeong-Soo; Lee, Gang-Woo; Dotel, Pratik; Lee, Jong-Won; Cha, Minjun; Yoon, Ji-Ho

2015-05-19

Many studies have focused on desalination via hydrate formation; however, for their potential application, knowledge pertaining to thermodynamic stability, formation kinetics, and guest occupation behavior in clathrate hydrates needs to be determined. Herein, the phase equilibria of SF6 hydrates in the presence of NaCl solutions (0, 2, 4, and 10 wt %) were monitored in the temperature range of 277-286 K and under pressures of up to 1.4 MPa. The formation kinetics of SF6 hydrates in the presence of NaCl solutions (0, 2, and 4 wt %) was also investigated. Gas consumption curves of SF6 hydrates showed that a pure SF6 hydrate system allowed fast hydrate growth as well as high conversion yield, whereas SF6 hydrate in the presence of NaCl solutions showed retarded hydrate growth rate as well as low conversion yield. In addition, structural identification of SF6 hydrates with and without NaCl solutions was performed using spectroscopic tools such as Raman spectroscopy and X-ray diffraction. The Raman spectrometer was also used to evaluate the temperature-dependent release behavior of guest molecules in SF6 and SF6 + 4 wt % NaCl hydrates. The results indicate that whereas SF6 hydrate starts to decompose at around 240 K, the escape of SF6 molecules in SF6 + 4 wt % NaCl hydrate is initiated rapidly at around 205 K. The results of this study can provide a better understanding of guest-host interaction in electrolyte-containing systems.

Comparison of Polyethylene Glycol-Electrolyte Solution vs Polyethylene Glycol-3350 for the Treatment of Fecal Impaction in Pediatric Patients

PubMed Central

Boles, Erin E.; Gaines, Cameryn L.

2015-01-01

OBJECTIVES: The objective of this study was to evaluate the safety and efficacy of polyethylene glycol-electrolyte solution vs polyethylene glycol-3350 for the treatment of fecal impaction in pediatric patients. METHODS: A retrospective, observational, institutional review board–approved study was conducted over a 1-year time period. Patients were included in the study if they were admitted to the hospital with a diagnosis of fecal impaction or constipation and were treated with either polyethylene glycol-electrolyte solution (PEG-ES) or polyethylene glycol-3350 (PEG-3350). Patients were excluded if they were discharged prior to resolution of treatment and/or did not receive PEG-ES or PEG-3350. RESULTS: Fifty-one patients (ranging in age from 1 month to 15 years) were evaluated: 23 patients received PEG-ES and 28 patients received PEG-3350. Sex, race, age, and weight were not statistically different between the 2 groups. Resolution of fecal impaction was not significantly different between PEG-ES vs PEG-3350 (87% and 86%, respectively; p = 0.87). There was only 1 reported side effect with PEG-3350, vs 11 reported side effects with PEG-ES (p < 0.01). CONCLUSIONS: Theses results suggest that PEG-3350 is as effective as PEG-ES for the treatment of fecal impaction in pediatric patients and is associated with fewer side effects. PMID:26170773

Electrolytic cell stack with molten electrolyte migration control

DOEpatents

Kunz, H. Russell; Guthrie, Robin J.; Katz, Murray

1988-08-02

An electrolytic cell stack includes inactive electrolyte reservoirs at the upper and lower end portions thereof. The reservoirs are separated from the stack of the complete cells by impermeable, electrically conductive separators. Reservoirs at the negative end are initially low in electrolyte and the reservoirs at the positive end are high in electrolyte fill. During stack operation electrolyte migration from the positive to the negative end will be offset by the inactive reservoir capacity. In combination with the inactive reservoirs, a sealing member of high porosity and low electrolyte retention is employed to limit the electrolyte migration rate.

Electrolytic cell stack with molten electrolyte migration control

DOEpatents

Kunz, H.R.; Guthrie, R.J.; Katz, M.

1987-03-17

An electrolytic cell stack includes inactive electrolyte reservoirs at the upper and lower end portions thereof. The reservoirs are separated from the stack of the complete cells by impermeable, electrically conductive separators. Reservoirs at the negative end are initially low in electrolyte and the reservoirs at the positive end are high in electrolyte fill. During stack operation electrolyte migration from the positive to the negative end will be offset by the inactive reservoir capacity. In combination with the inactive reservoirs, a sealing member of high porosity and low electrolyte retention is employed to limit the electrolyte migration rate. 5 figs.

Balancing Osmotic Pressure of Electrolytes for Nanoporous Membrane Vanadium Redox Flow Battery with a Draw Solute.

PubMed

Yan, Ligen; Li, Dan; Li, Shuaiqiang; Xu, Zhi; Dong, Junhang; Jing, Wenheng; Xing, Weihong

2016-12-28

Vanadium redox flow batteries with nanoporous membranes (VRFBNM) have been demonstrated to be good energy storage devices. Yet the capacity decay due to permeation of vanadium and water makes their commercialization very difficult. Inspired by the forward osmosis (FO) mechanism, the VRFBNM battery capacity decrease was alleviated by adding a soluble draw solute (e.g., 2-methylimidazole) into the catholyte, which can counterbalance the osmotic pressure between the positive and negative half-cell. No change of the electrolyte volume has been observed after VRFBNM being operated for 55 h, revealing that the permeation of water and vanadium ions was effectively limited. Consequently, the Coulombic efficiency (CE) of nanoporous TiO 2 vanadium redox flow battery (VRFB) was enhanced from 93.5% to 95.3%, meanwhile, its capacity decay was significantly suppressed from 60.7% to 27.5% upon the addition of soluble draw solute. Moreover, the energy capacity of the VRFBNM was noticeably improved from 297.0 to 406.4 mAh remarkably. These results indicate balancing the osmotic pressure via the addition of draw solute can restrict pressure-dependent vanadium permeation and it can be established as a promising method for up-scaling VRFBNM application.

Nonflammable gel electrolyte containing alkyl phosphate for rechargeable lithium batteries

NASA Astrophysics Data System (ADS)

Yoshimoto, Nobuko; Niida, Yoshihiro; Egashira, Minato; Morita, Masayuki

A nonflammable polymeric gel electrolyte has been developed for rechargeable lithium battery systems. The gel film consists of poly(vinylidenefluoride- co-hexafluoropropylene) (PVdF-HFP) swollen with lithium hexafluorophosphate (LiPF 6) solution in ternary solvent containing trimethyl phosphate (TMP). High ionic conductivity of 6.2 mS cm -1 at 20 °C was obtained for the gel electrolyte consisting of 0.8 M LiPF 6/EC + DEC + TMP (55:25:20) with PVdF-HFP, which is comparable to that of the liquid electrolyte containing the same electrolytic salt. Addition of a small amount of vinylene carbonate (VC) in the gel electrolyte improved the rechargeability of a graphite electrode. The rechargeable capacity of the graphite in the gel containing VC was ca. 300 mAh g -1, which is almost the same as that in a conventional liquid electrolyte system.

Molecular simulations of diffusion in electrolytes

NASA Astrophysics Data System (ADS)

Wheeler, Dean Richard

This work demonstrates new methodologies for simulating multicomponent diffusion in concentrated solutions using molecular dynamics (MD). Experimental diffusion data for concentrated multicomponent solutions are often lacking, as are accurate methods of predicting diffusion for nonideal solutions. MD can be a viable means of understanding and predicting multicomponent diffusion. While there have been several prior reports of MD simulations of mutual diffusion, no satisfactory expressions for simulating Stefan-Maxwell diffusivities for an arbitrary number of species exist. The approaches developed here allow for the computation of a full diffusion matrix for any number of species in both nonequilibrium and equilibrium MD ensembles. Our nonequilibrium approach is based on the application of constant external fields to drive species diffusion. Our equilibrium approach uses a newly developed Green-Kubo formula for Stefan-Maxwell diffusivities. In addition, as part of this work, we demonstrate a widely applicable means of increasing the computational efficiency of the Ewald sum, a technique for handling long-range Coulombic interactions in simulations. The theoretical development is applicable to any solution which can be simulated using MD; nevertheless, our primary interest is in electrochemical applications. To this end, the methods are tested by simulations of aqueous salt solutions and lithium-battery electrolytes. KCl and NaCl aqueous solutions were simulated over the concentration range 1 to 4 molal. Intermolecular-potential models were parameterized for these transport-based simulations. This work is the first to simulate all three independent diffusion coefficients for aqueous NaCl and KCl solutions. The results show that the nonequilibrium and equilibrium methods are consistent with each other, and in moderate agreement with experiment. We simulate lithium-battery electrolytes containing LiPF6 in propylene carbonate and mixed ethylene carbonate

Light emission from organic single crystals operated by electrolyte doping

NASA Astrophysics Data System (ADS)

Matsuki, Keiichiro; Sakanoue, Tomo; Yomogida, Yohei; Hotta, Shu; Takenobu, Taishi

2018-03-01

Light-emitting devices based on electrolytes, such as light-emitting electrochemical cells (LECs) and electric double-layer transistors (EDLTs), are solution-processable devices with a very simple structure. Therefore, it is necessary to apply this device structure into highly fluorescent organic materials for future printed applications. However, owing to compatibility problems between electrolytes and organic crystals, electrolyte-based single-crystal light-emitting devices have not yet been demonstrated. Here, we report on light-emitting devices based on organic single crystals and electrolytes. As the fluorescent materials, α,ω-bis(biphenylyl)terthiophene (BP3T) and 5,6,11,12-tetraphenylnaphthacene (rubrene) single crystals were selected. Using ionic liquids as electrolytes, we observed clear light emission from BP3T LECs and rubrene EDLTs.

Harmonics distribution of iron oxide nanoparticles solutions under diamagnetic background

NASA Astrophysics Data System (ADS)

Saari, Mohd Mawardi; Che Lah, Nurul Akmal; Sakai, Kenji; Kiwa, Toshihiko; Tsukada, Keiji

2018-04-01

The static and dynamic magnetizations of low concentrated multi-core iron oxide nanoparticles solutions were investigated by a specially developed high-Tc Superconducting Quantum Interference Device (SQUID) magnetometer. The size distribution of iron oxide cores was determined from static magnetization curves concerning different concentrations. The simulated harmonics distribution was compared to the experimental results. Effect of the diamagnetic background from carrier liquid to harmonics distribution was investigated with respect to different intensity and position of peaks in the magnetic moment distribution using a numerical simulation. It was found that the diamagnetic background from carrier liquid of iron oxide nanoparticles affected the harmonics distribution as their concentration decreased and depending on their magnetic moment distribution. The first harmonic component was susceptible to the diamagnetic contribution of carrier liquid when the concentration was lower than 24 μg/ml. The second and third harmonics were affected when the peak position of magnetic moment distribution was smaller than m = 10-19 Am2 and the concentration was 10 ng/ml. A highly sensitive detection up to sub-nanogram of iron oxide nanoparticles in solutions can be achieved by utilizing second and third harmonic components.

[Computer modeling the hydrostatic pressure characteristics of the membrane potential for polymeric membrane, separated non-homogeneous electrolyte solutions].

PubMed

Slezak, Izabella H; Jasik-Slezak, Jolanta; Rogal, Mirosława; Slezak, Andrzej

2006-01-01

On the basis of model equation depending the membrane potential deltapsis, on mechanical pressure difference (deltaP), concentration polarization coefficient (zetas), concentration Rayleigh number (RC) and ratio concentration of solutions separated by membrane (Ch/Cl), the characteristics deltapsis = f(deltaP)zetas,RC,Ch/Cl for steady values of zetas, RC and Ch/Cl in single-membrane system were calculated. In this system neutral and isotropic polymeric membrane oriented in horizontal plane, the non-homogeneous binary electrolytic solutions of various concentrations were separated. Nonhomogeneity of solutions is results from creations of the concentration boundary layers on both sides of the membrane. Calculations were made for the case where on a one side of the membrane aqueous solution of NaCl at steady concentration 10(-3) mol x l(-1) (Cl) was placed and on the other aqueous solutions of NaCl at concentrations from 10(-3) mol x l(-1) to 2 x 10(-2) mol x l(-1) (Ch). Their densities were greater than NaCl solution's at 10(-3) mol x l(-1). It was shown that membrane potential depends on hydrodynamic state of a complex concentration boundary layer-membrane-concentration boundary layer, what is controlled by deltaP, Ch/Cl, RC and zetas.

[Evaluation of the Peusner's coefficients matrix for polymeric membrane and ternary non-electrolyte solutions].

PubMed

Jasik-Slęzak, Jolanta; Slęzak-Prochazka, Izabella; Slęzak, Andrzej

2014-01-01

A system of network forms of Kedem-Katchalsky (K-K) equations for ternary non-electrolyte solutions is made of eight matrix equations containing Peusner's coefficients R(ij), L(ij), H(ij), W(ij), K(ij), N(ij), S(ij) or P(ij) (i, j ∈ {1, 2, 3}). The equations are the result of symmetric or hybrid transformation of the classic form of K-K equations by the use of methods of Peusner's network thermodynamics (PNT). Calculating concentration dependences of the determinant of Peusner's coefficients matrixes R(ij), L(ij), H(ij), W(ij), S(ij), N(ij), K(ij) and P(ij) (i, j ∈ {1, 2, 3}). The material used in the experiment was a hemodialysis Nephrophan membrane with specified transport properties (L(p), σ, Ω) in aqueous glucose and ethanol solution. The method involved equations for determinants of the matrixes coefficients R(ij), L(ij), H(ij), W(ij), S(ij), N(ij), K(ij) or P(ij) (i, j ∈ {1, 2, 3}). The objective of calculations were dependences of determinants of Peusner's coeffcients matrixes R(ij), L(ij), H(ij), W(ij), S(ij), N(ij), K(ij) or P(ij) (i, j ∈ {1, 2, 3}) within the conditions of solution homogeneity upon an average concentration of one component of solution in the membrane (C1) with a determined value of the second component (C2). The method of calculating the determinants of Peusner's coeffcients matrixes R(ij), L(ij), H(ij), W(ij), S(ij), N(ij), K(ij) or P(ij) (i, j ∈ {1, 2, 3}) is a new tool that may be applicable in studies on membrane transport. Calculations showed that the coefficients are sensitive to concentration and composition of solutions separated by a polymeric membrane.

ELECTROLYTIC REDUCTION OF NITRIC ACID SOLUTIONS

DOEpatents

Alter, H.W.; Barney, D.L.

1958-09-30

A process is presented for the treatment of radioactivc waste nitric acid solutions. The nitric acid solution is neutralized with an alkali metal hydroxide in an amount sufficient to precipitate insoluble hydroxides, and after separation of the precipitate the solution is electrolyzed to convert the alkali nitrate formed, to alkali hydroxide, gaseous ammonla and oxygen. The solution is then reusable after reducing the volume by evaporating the water and dissolved ammonia.

Electrode effects on temporal changes in electrolyte pH and redox potential for water treatment

PubMed Central

Ciblak, Ali; Mao, Xuhui; Padilla, Ingrid; Vesper, Dorothy; Alshawabkeh, Iyad; Alshawabkeh, Akram N.

2012-01-01

The performance of electrochemical remediation methods could be optimized by controlling the physicochemical conditions of the electrochemical redox system. The effects of anode type (reactive or inert), current density and electrolyte composition on the temporal changes in pH and redox potential of the electrolyte were evaluated in divided and mixed electrolytes. Two types of electrodes were used: iron as a reactive electrode and mixed metal oxide coated titanium (MMO) as an inert electrode. Electric currents of 15, 30, 45 and 60 mA (37.5 mA L−1, 75 mA L−1, 112.5 mA L−1 and 150 mA L−1) were applied. Solutions of NaCl, Na2SO4 and NaHCO3 were selected to mimic different wastewater or groundwater composition. Iron anodes resulted in highly reducing electrolyte conditions compared to inert anodes. Electrolyte pH was dependent on electrode type, electrolyte composition and current density. The pH of mixed-electrolyte was stable when MMO electrodes were used. When iron electrodes were used, the pH of electrolyte with relatively low current density (37.5 mA L−1) did not show significant changes but the pH increased sharply for relatively high current density (150 mA L−1). Sulfate solution showed more basic and relatively more reducing electrolyte condition compared to bicarbonate and chloride solution. The study shows that a highly reducing environment could be achieved using iron anodes in divided or mixed electrolytes and the pH and redox potential could be optimized by using appropriate current and polarity reversal. PMID:22416866

Fluid and Electrolyte Balance model (FEB)

NASA Technical Reports Server (NTRS)

Fitzjerrell, D. G.

1973-01-01

The effects of various oral input water loads on solute and water distribution throughout the body are presented in the form of a model. The model was a three compartment model; the three compartments being plasma, interstitial fluid and cellular fluid. Sodium, potassium, chloride and urea were the only major solutes considered explicitly. The control of body water and electrolyte distribution was affected via drinking and hormone levels.

Effects of two different strategies of fluid administration on inflammatory mediators, plasma electrolytes and acid/base disorders in patients undergoing major abdominal surgery: a randomized double blind study

PubMed Central

2013-01-01

Background Administration of normal saline might increase circulating levels of pro-inflammatory cytokines and may cause variation of plasmatic electrolytic and hyperchloremic acidosis, which in turn can impair renal function. Hence the use of balanced solutions could influence the inflammatory cascade triggered by the surgical procedures, the plasmatic electrolyte concentration, the acid–base equilibrium, and the renal function. Methods This is a double blind randomized trial. Forty patients undergoing major abdominal surgery (bowel cancer) were allocated in two groups, the balanced solution (BS) group in which the fluids administered were balanced solutions (colloids and crystalloids); and the unbalanced solution (UBS) group in which the fluids administered were unbalanced solutions (colloids and crystalloids). Measurements were performed after anaesthesia induction (T0), at the end of surgery (T1), within 2 h after surgery (T2) and 24 h after the beginning of surgery (T3). The following data were collected: 1) active matrix metalloproteinase 9 (MMP-9) and its tissue inhibitor (TIMP-1), IL-6, IL-8, IL-10; 2) blood gases variables; 3) electrolytes, albumin, total serum protein and the strong ion difference; 4) neutrophil gelatinase-associated lipocalin (NGAL) from urinary sample. Results The BS group exhibited higher circulating level of IL-10 and TIMP-1 and lower level of active MMP-9. The UBS group experienced hypercloremia, hypocalcemia, hypomagnesemia, worse acid–base equilibrium and higher level of NGAL. Conclusions The use of balanced solutions was responsible of less alteration of plasmatic electrolytes, acid–base equilibrium, kidney function and it might be associated with an early anti-inflammatory mechanisms triggering. Trial registration ClinicalTrials.gov (Ref: NCT01320891). PMID:24059479

Molecular Level Structure and Dynamics of Electrolytes Using 17O Nuclear Magnetic Resonance Spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murugesan, Vijayakumar; Han, Kee Sung; Hu, Jianzhi

2017-03-19

Electrolytes help harness the energy from electrochemical processes by serving as solvents and transport media for redox-active ions. Molecular-level interactions between ionic solutes and solvent molecules – commonly referred to as solvation phenomena – give rise to many functional properties of electrolytes such as ionic conductivity, viscosity, and stability. It is critical to understand the evolution of solvation phenomena as a function of competing counterions and solvent mixtures to predict and design the optimal electrolyte for a target application. Probing oxygen environments is of great interest as oxygens are located at strategic molecular sites in battery solvents and are directlymore » involved in inter- and intramolecular solvation interactions. NMR signals from 17O nuclei in battery electrolytes offer nondestructive bulk measurements of isotropic shielding, electric field gradient tensors, and transverse and longitudinal relaxation rates, which are excellent means for probing structure, bonding, and dynamics of both solute and solvent molecules. This article describes the use of 17O NMR spectroscopy in probing the solvation structures of various electrolyte systems ranging from transition metal ions in aqueous solution to lithium cations in organic solvent mixtures.« less

Lithium sulfur batteries and electrolytes and sulfur cathodes thereof

DOEpatents

Visco, Steven J.; Goncharenko, Nikolay; Nimon, Vitaliy; Petrov, Alexei; Nimon, Yevgeniy S.; De Jonghe, Lutgard C.; Katz, Bruce D.; Loginova, Valentina

2017-05-23

Lithium sulfur battery cells that use water as an electrolyte solvent provide significant cost reductions. Electrolytes for the battery cells may include water solvent for maintaining electroactive sulfur species in solution during cell discharge and a sufficient amount of a cycle life-enhancing compound that facilitates charging at the cathode. The combination of these two components enhances one or more of the following cell attributes: energy density, power density and cycle life. For instance, in applications where cost per Watt-Hour (Wh) is paramount, such as grid storage and traction applications, the use of an aqueous electrolyte in combination with inexpensive sulfur as the cathode active material can be a key enabler for the utility and automotive industries, for example, providing a cost effective and compact solution for load leveling, electric vehicles and renewable energy storage. Sulfur cathodes, and methods of fabricating lithium sulfur cells, in particular for loading lithium sulfide into the cathode structures, provide further advantages.

Manganese oxide electrochemical capacitor with potassium poly(acrylate) hydrogel electrolyte

NASA Astrophysics Data System (ADS)

Lee, Kuang-Tsin; Wu, Nae-Lih

An aqueous gel electrolyte has for the first time been successfully applied to the MnO 2· nH 2O-based pseudocapacitive electrochemical capacitors (ECs). The gel electrolyte is made of potassium poly(acrylate) (PAAK) polymer and aqueous solution of KCl. With the selected composition, PAAK:KCl:H 2O = 9.0%:6.7%:84.3% by weight, the gel shows no fluidity, possessing an ionic conductivity in the order of 10 -1 S cm -1. The gel electrolyte has been found to give substantially higher specific capacitances than those in the liquid electrolyte with the same salt (KCl) composition (1 M) and high power capability (>10 kW/kg).

Solid oxide fuel cells with bi-layered electrolyte structure

NASA Astrophysics Data System (ADS)

Zhang, Xinge; Robertson, Mark; Decès-Petit, Cyrille; Xie, Yongsong; Hui, Rob; Qu, Wei; Kesler, Olivera; Maric, Radenka; Ghosh, Dave

In this work, we have developed solid oxide fuel cells with a bi-layered electrolyte of 2 μm SSZ and 4 μm SDC using tape casting, screen printing, and co-firing processes. The cell reached power densities of 0.54 W cm -2 at 650 °C and 0.85 W cm -2 at 700 °C, with open circuit voltage (OCV) values larger than 1.02 V. The electrical leaking between anode and cathode through an SDC electrolyte has been blocked in the bi-layered electrolyte structure. However, both the electrolyte resistance (R el) and electrode polarization resistance (R p,a+c) increased in comparison to cells with single-layered SDC electrolytes. The formation of a solid solution of (Ce, Zr)O 2- x during sintering process and the flaws in the bi-layered electrolyte structure seem to be the main causes for the increase in the R el value (0.32 Ω cm 2) at 650 °C, which is almost one order of magnitude higher than the calculated value.

Probing the electrolyte infiltration behaviour of activated carbon supercapacitor electrodes by in situ neutron scattering using aqueous NaCl as electrolyte

DOE PAGES

Liu, Yiqun; Li, Chen; Liu, Cong; ...

2018-04-24

In situ contrast-matched neutron scattering was used to probe the electrolyte infiltration behavior of activated supercapacitor carbon electrodes using an aquoeus 1 M NaCl solution. It was found that only about 20% of the pore volume was infiltrated at chemical equilibrium. The partial infiltration can be attributed to the co-existence of hydrophilic and hydrophilic pores. As a result, the study suggests that for the achievement of optimal capacitance, supercapacitor electrodes should be evacuated before electrolyte infiltration.

Probing the electrolyte infiltration behaviour of activated carbon supercapacitor electrodes by in situ neutron scattering using aqueous NaCl as electrolyte

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Yiqun; Li, Chen; Liu, Cong

In situ contrast-matched neutron scattering was used to probe the electrolyte infiltration behavior of activated supercapacitor carbon electrodes using an aquoeus 1 M NaCl solution. It was found that only about 20% of the pore volume was infiltrated at chemical equilibrium. The partial infiltration can be attributed to the co-existence of hydrophilic and hydrophilic pores. As a result, the study suggests that for the achievement of optimal capacitance, supercapacitor electrodes should be evacuated before electrolyte infiltration.

Sparingly Solvating Electrolytes for High Energy Density Lithium-Sulfur Batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Lei; Curtiss, Larry A.; Zavadil, Kevin R.

2016-07-11

Moving to lighter and less expensive battery chemistries compared to lithium-ion requires the control of energy storage mechanisms based on chemical transformations rather than intercalation. Lithium sulfur (Li/S) has tremendous theoretical specific energy, but contemporary approaches to control this solution-mediated, precipitation-dissolution chemistry requires using large excesses of electrolyte to fully solubilize the polysulfide intermediate. Achieving reversible electrochemistry under lean electrolyte operation is the only path for Li/S to move beyond niche applications to potentially transformational performance. An emerging topic for Li/S research is the use of sparingly solvating electrolytes and the creation of design rules for discovering new electrolyte systemsmore » that fundamentally decouple electrolyte volume from reaction mechanism. This perspective presents an outlook for sparingly solvating electrolytes as the key path forward for longer-lived, high-energy density Li/S batteries including an overview of this promising new concept and some strategies for accomplishing it.« less

Sparingly solvating electrolytes for high energy density Lithium–sulfur batteries

DOE PAGES

Cheng, Lei; Curtiss, Larry A.; Zavadil, Kevin R.; ...

2016-07-11

Moving to lighter and less expensive battery chemistries compared to lithium-ion requires the control of energy storage mechanisms based on chemical transformations rather than intercalation. Lithium sulfur (Li/S) has tremendous theoretical specific energy, but contemporary approaches to control this solution-mediated, precipitation-dissolution chemistry requires using large excesses of electrolyte to fully solubilize the polysulfide intermediate. Achieving reversible electrochemistry under lean electrolyte operation is the only path for Li/S to move beyond niche applications to potentially transformational performance. An emerging topic for Li/S research is the use of sparingly solvating electrolytes and the creation of design rules for discovering new electrolyte systemsmore » that fundamentally decouple electrolyte volume from reaction mechanism. Furthermore, this perspective presents an outlook for sparingly solvating electrolytes as the key path forward for longer-lived, high-energy density Li/S batteries including an overview of this promising new concept and some strategies for accomplishing it.« less

Electrolyte solutions at curved electrodes. I. Mesoscopic approach

NASA Astrophysics Data System (ADS)

Reindl, Andreas; Bier, Markus; Dietrich, S.

2017-04-01

Within the Poisson-Boltzmann approach, electrolytes in contact with planar, spherical, and cylindrical electrodes are analyzed systematically. The dependences of their capacitance C on the surface charge density σ and the ionic strength I are examined as a function of the wall curvature. The surface charge density has a strong effect on the capacitance for small curvatures, whereas for large curvatures the behavior becomes independent of σ. An expansion for small curvatures gives rise to capacitance coefficients which depend only on a single parameter, allowing for a convenient analysis. The universal behavior at large curvatures can be captured by an analytic expression.

Molecular adsorption at electrolyte/α-Al2O3 interface of aluminum electrolytic capacitor revealed by sum frequency vibrational spectroscopy.

PubMed

Jia, Ming; Hu, Xiaoyu; Liu, Jin; Liu, Yexiang; Ai, Liang

2017-05-21

The operating voltage of an aluminum electrolytic capacitor is determined by the breakdown voltage (U b ) of the Al 2 O 3 anode. U b is related to the molecular adsorption at the Al 2 O 3 /electrolyte interface. Therefore, we have employed sum-frequency vibrational spectroscopy (SFVS) to study the adsorption states of a simple electrolyte, ethylene glycol (EG) solution with ammonium adipate, on an α-Al 2 O 3 surface. In an acidic electrolyte (pH < 6), the Al 2 O 3 surface is positively charged. The observed SFVS spectra show that long chain molecules poly ethylene glycol and ethylene glycol adipate adopt a "lying" orientation at the interface. In an alkaline electrolyte (pH > 8), the Al 2 O 3 surface is negatively charged and the short chain EG molecules adopt a "tilting" orientation. The U b results exhibit a much higher value at pH < 6 compared with that at pH > 8. Since the "lying" long chain molecules cover and protect the Al 2 O 3 surface, U b increases with a decrease of pH. These findings provide new insights to study the breakdown mechanisms and to develop new electrolytes for high operating voltage capacitors.

Use of Piggyback Electrolytes for Patients Receiving Individually Prescribed vs Premixed Parenteral Nutrition.

PubMed

Busch, Rebecca A; Curtis, Caitlin S; Leverson, Glen E; Kudsk, Kenneth A

2015-07-01

Parenteral nutrition (PN) is available as individualized prescriptions frequently prepared with an automated compounding device or as commercially prepared premixed solutions. Our institution exclusively used individualized PN until an amino acid shortage forced a temporary switch to premixed solutions. In general, premixed solutions contain lower electrolyte levels than individualized formulations prescribed for patients with normal organ function. We aimed to quantify supplemental intravenous piggyback (IVPB) electrolyte use in adult patients receiving individualized and premixed PN and to quantify any effect on difference in the cost of therapy. We compared use of supplemental IVPB electrolytes administered to patients receiving PN during consecutive periods prior to and during the amino acid shortage. Electrolyte IVPBs tabulated were potassium chloride, 10 and 20 mEq; magnesium sulfate, 2 g and 4 g; potassium phosphate, 7.5 and 15 mmol; and sodium phosphate, 7.5 and 15 mmol IVPB. There was no statistical difference in the number of PN formulations administered per day during each period (14.7 ± 3.9 vs 14.0 ± 2.6, individualized vs premixed, respectively). Total IVPB electrolytes prescribed per day increased significantly from the individualized PN period to the premixed PN period (7.03 ± 3.8 vs 13.8 ± 6.8; P < .0001). The additional IVPB electrolyte supplementation required in patients receiving premixed PN was associated with an additional $11,855.74 cost per 30 days of therapy compared with those who received individualized PN. Inpatient use of premixed PN results in a significant increase in IVPB electrolyte supplementation and cost compared with individualized PN use. © 2014 American Society for Parenteral and Enteral Nutrition.

Electrolytic method for the production of lithium using a lithium-amalgam electrode

DOEpatents

Cooper, John F.; Krikorian, Oscar H.; Homsy, Robert V.

1979-01-01

A method for recovering lithium from its molten amalgam by electrolysis of the amalgam in an electrolytic cell containing as a molten electrolyte a fused-salt consisting essentially of a mixture of two or more alkali metal halides, preferably alkali metal halides selected from lithium iodide, lithium chloride, potassium iodide and potassium chloride. A particularly suitable molten electrolyte is a fused-salt consisting essentially of a mixture of at least three components obtained by modifying an eutectic mixture of LiI-KI by the addition of a minor amount of one or more alkali metal halides. The lithium-amalgam fused-salt cell may be used in an electrolytic system for recovering lithium from an aqueous solution of a lithium compound, wherein electrolysis of the aqueous solution in an aqueous cell in the presence of a mercury cathode produces a lithium amalgam. The present method is particularly useful for the regeneration of lithium from the aqueous reaction products of a lithium-water-air battery.

LiGa(OTf)(sub 4) as an Electrolyte Salt for Li-Ion Cells

NASA Technical Reports Server (NTRS)

Reddy, V. Prakash; Prakash, G. K. Syria; Hu, Jinbo; Yan, Ping; Smart, Marshall; Bugga, ratnakumar; Chin, Keith; Surampudi, Subarao

2008-01-01

Lithium tetrakis(trifluoromethane sulfo - nato)gallate [abbreviated "LiGa(OTf)4" (wherein "OTf" signifies trifluoro - methanesulfonate)] has been found to be promising as an electrolyte salt for incorporation into both liquid and polymer electrolytes in both rechargeable and non-rechargeable lithium-ion electrochemical cells. This and other ingredients have been investigated in continuing research oriented toward im proving the performances of rechargeable lithium-ion electrochemical cells, especially at low temperatures. This research at earlier stages, and the underlying physical and chemical principles, were reported in numerous previous NASA Tech Briefs articles. As described in more detail in those articles, lithiumion cells most commonly contain nonaqueous electrolyte solutions consisting of lithium hexafluorophosphate (LiPF6) dissolved in mixtures of cyclic and linear alkyl carbonates, including ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), and ethyl methyl carbonate (EMC). Although such LiPF6-based electrolyte solutions are generally highly ionically conductive and electrochemically stable, as needed for good cell performance, there is interest in identifying alternate lithium electrolyte salts that, relative to LiPF6, are more resilient at high temperature and are less expensive. Experiments have been performed on LiGa(OTf)4 as well as on several other candidate lithium salts in pursuit of this interest. As part of these experiments, LiGa(OTf)4 was synthesized by the reaction of Ga(OTf)3 with an equimolar portion of LiOTf in a solvent consisting of anhydrous acetonitrile. Evaporation of the solvent yielded LiGa(OTf)4 as a colorless crystalline solid. The LiGa(OTf)4 and the other salts were incorporated into solutions with PC and DMC. The resulting electrolyte solutions exhibited reasonably high ionic conductivities over a relatively wide temperature range down to 40 C (see figure). In cyclic

Optimized Li-Ion Electrolytes Containing Fluorinated Ester Co-Solvents

NASA Technical Reports Server (NTRS)

Prakash, G. K. Surya; Smart, Marshall; Smith, Kiah; Bugga, Ratnakumar

2010-01-01

A number of experimental lithium-ion cells, consisting of MCMB (meso-carbon microbeads) carbon anodes and LiNi(0.8)Co(0.2)O2 cathodes, have been fabricated with increased safety and expanded capability. These cells serve to verify and demonstrate the reversibility, low-temperature performance, and electrochemical aspects of each electrode as determined from a number of electrochemical characterization techniques. A number of Li-ion electrolytes possessing fluorinated ester co-solvents, namely trifluoroethyl butyrate (TFEB) and trifluoroethyl propionate (TFEP), were demonstrated to deliver good performance over a wide temperature range in experimental lithium-ion cells. The general approach taken in the development of these electrolyte formulations is to optimize the type and composition of the co-solvents in ternary and quaternary solutions, focusing upon adequate stability [i.e., EC (ethylene carbonate) content needed for anode passivation, and EMC (ethyl methyl carbonate) content needed for lowering the viscosity and widening the temperature range, while still providing good stability], enhancing the inherent safety characteristics (incorporation of fluorinated esters), and widening the temperature range of operation (the use of both fluorinated and non-fluorinated esters). Further - more, the use of electrolyte additives, such as VC (vinylene carbonate) [solid electrolyte interface (SEI) promoter] and DMAc (thermal stabilizing additive), provide enhanced high-temperature life characteristics. Multi-component electrolyte formulations enhance performance over a temperature range of -60 to +60 C. With the need for more safety with the use of these batteries, flammability was a consideration. One of the solvents investigated, TFEB, had the best performance with improved low-temperature capability and high-temperature resilience. This work optimized the use of TFEB as a co-solvent by developing the multi-component electrolytes, which also contain non

The Effect of Ionic Strength on the Solubility of an Electrolyte

ERIC Educational Resources Information Center

Willey, Joan D.

2004-01-01

A simple experiment was conducted for studying and demonstrating visually and dramatically the effect of ionic strength on the solubility of an electrolyte is described. It is seen that the experiment visually illustrates the effect of ionic strength on electrolyte solubility by the appearance of the two solutions and by the difference in the…

Electrical, structural, thermal and electrochemical properties of corn starch-based biopolymer electrolytes.

PubMed

Liew, Chiam-Wen; Ramesh, S

2015-06-25

Biopolymer electrolytes containing corn starch, lithium hexafluorophosphate (LiPF6) and ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate (BmImPF6) are prepared by solution casting technique. Temperature dependence-ionic conductivity studies reveal Vogel-Tamman-Fulcher (VTF) relationship which is associated with free volume theory. Ionic liquid-based biopolymer electrolytes show lower glass transition temperature (Tg) than ionic liquid-free biopolymer electrolyte. X-ray diffraction (XRD) studies demonstrate higher amorphous region of ionic liquid-added biopolymer electrolytes. In addition, the potential stability window of the biopolymer electrolyte becomes wider and stable up to 2.9V. Conclusively, the fabricated electric double layer capacitor (EDLC) shows improved electrochemical performance upon addition of ionic liquid into the biopolymer electrolyte. The specific capacitance of EDLC based on ionic liquid-added polymer electrolyte is relatively higher than that of ionic liquid-free polymer electrolyte as depicted in cyclic voltammogram. Copyright © 2015 Elsevier Ltd. All rights reserved.

Gex-Model Using Local Area Fraction for Binary Electrolyte Systems

NASA Astrophysics Data System (ADS)

Haghtalab, Ali; Joda, Marzieh

2007-06-01

The correlation and prediction of phase equilibria of electrolyte systems are essential in the design and operation of many industrial processes such as downstream processing in biotechnology, desalination, hydrometallurgy, etc. In this research, the local composition non-random two liquid-nonrandom factor (NRTL-NRF) model of Haghtalab and Vera was extended for uni-univalent aqueous electrolyte solutions. Based on the assumptions of the NRTL-NRF model, excess Gibbs free energy ( g E) functions were derived for binary electrolyte systems. In this work, the local area fraction was applied and the modified model of NRTL-NRF was developed with either an equal or unequal surface area of an anion to the surface area of a cation. The modified NRTL-NRF models consist of two contributions, one due to long-range forces represented by the Debye-Hückel theory, and the other due to short-range forces, represented by local area fractions of species through nonrandom factors. Each model contains only two adjustable parameters per electrolyte. In addition, the model with unequal surface area of ionic species gives better results in comparison with the second new model with equal surface area of ions. The results for the mean activity coefficients for aqueous solutions of uni-univalent electrolytes at 298.15 K showed that the present model is more accurate than the original NRTL-NRF model.

Liquid-Feed Methanol Fuel Cell With Membrane Electrolyte

NASA Technical Reports Server (NTRS)

Surampudi, Subbarao; Narayanan, S. R.; Halpert, Gerald; Frank, Harvey; Vamos, Eugene

1995-01-01

Fuel cell generates electricity from direct liquid feed stream of methanol/water solution circulated in contact with anode, plus direct gaseous feed stream of air or oxygen in contact with cathode. Advantages include relative simplicity and elimination of corrosive electrolytic solutions. Offers potential for reductions in size, weight, and complexity, and for increases in safety of fuel-cell systems.

The effect of electrolytes on dolomite dissolution: nanoscale observations using in situ Atomic Force Microscopy

NASA Astrophysics Data System (ADS)

Urosevic, Maja; Ruiz-Agudo, Encarnacion; Putnis, Christine V.; Cardell, Carolina; Rodriguez-Navarro, Carlos; Putnis, Andrew

2010-05-01

carbonate rocks, both in the natural environment, as well as in stone buildings and statuary, where the amount of solutes in pore waters is significant and can vary depending on evaporation and condensation phenomena. References Higgins, S.R.; Hu, X. Self-limiting growth on dolomite: Experimental observations with in situ atomic force microscopy. Geochimica et Cosmochimica Acta, 2005, 69 (8), 2085-2094. Morse, J.W.; Arvidson, R.S. The dissolution kinetics of major sedimentary carbonate minerals. Earth-Science Reviews, 2002, 58, 51-84. Ruiz-Agudo, E.; Kowacz, M.; Putnis, C.V.; Putnis, A. The role of background electrolytes on the kinetics and mechanism of calcite dissolution. Geochimica et Cosmochimica Acta, 2010, 74, 1256-1267.

Formulation of Ionic-Liquid Electrolyte To Expand the Voltage Window of Supercapacitors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van Aken, Katherine L.; Beidaghi, Majid; Gogotsi, Yury

An effective method to expand the operating potential window (OPW) of electrochemical capacitors based on formulating the ionic-liquid (IL) electrolytes is reported. Using model electrochemical cells based on two identical onion-like carbon (OLC) electrodes and two different IL electrolytes and their mixtures, it was shown that the asymmetric behavior of the electrolyte cation and anion toward the two electrodes limits the OPW of the cell and therefore its energy density. Also, a general solution to this problem is proposed by formulating the IL electrolyte mixtures to balance the capacitance of electrodes in a symmetric supercapacitor.

Electrolytic Polishing and Etching Techniques for Preparing Specimens of Bismuth and Antimony and Their Alloys: Materials and Structures.

DTIC Science & Technology

Electrolytic polishing was performed in a solution of methyl alcohol, sulphuric acid , hydrocloric acid and ethylene glycol. Etching was done...electrolytically in a 5 percent chromic acid solution. Use of these techniques has permitted detailed studies of the microstructures of bismuth-antimony single

Effects of electrolytes on redox potentials through ion pairing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bird, Matthew J.; Iyoda, Tomokazu; Bonura, Nicholas

Here, reduction potentials have been determined for two molecules, benzophenone (BzPh) and perylene (Per), effectively in the complete absence of electrolyte as well as in the presence of three different supporting electrolytes in the moderately polar solvent THF. A description of how this can be so, and qualifications, are described in the discussion section. The primary tool in this work, pulse radiolysis, measures electron transfer (ET) equilibria in solution to obtain differences in redox potentials. Voltammetry measures redox potentials by establishing ET equilibria at electrodes, but electrolytes are needed for current flow. Results here show that without electrolyte the redoxmore » potentials were 100–451 mV more negative than those with 100 mM electrolyte. These changes depended both on the molecule and the electrolyte. In THF the dominant contributor to stabilization of radical anions by electrolyte was ion pairing. An equation was derived to give changes in redox potentials when electrolyte is added in terms of ion pair dissociation constants and activity coefficients. Definite values were determined for energetics, ΔG d°, of ion pairing. Values of ΔG d° for pairs with TBA + give some doubt that it is a “weakly-coordinating cation.” Computations with DFT methods were moderately successful at describing the ion paring energies.« less

Effects of electrolytes on redox potentials through ion pairing

DOE PAGES

Bird, Matthew J.; Iyoda, Tomokazu; Bonura, Nicholas; ...

2017-09-21

Here, reduction potentials have been determined for two molecules, benzophenone (BzPh) and perylene (Per), effectively in the complete absence of electrolyte as well as in the presence of three different supporting electrolytes in the moderately polar solvent THF. A description of how this can be so, and qualifications, are described in the discussion section. The primary tool in this work, pulse radiolysis, measures electron transfer (ET) equilibria in solution to obtain differences in redox potentials. Voltammetry measures redox potentials by establishing ET equilibria at electrodes, but electrolytes are needed for current flow. Results here show that without electrolyte the redoxmore » potentials were 100–451 mV more negative than those with 100 mM electrolyte. These changes depended both on the molecule and the electrolyte. In THF the dominant contributor to stabilization of radical anions by electrolyte was ion pairing. An equation was derived to give changes in redox potentials when electrolyte is added in terms of ion pair dissociation constants and activity coefficients. Definite values were determined for energetics, ΔG d°, of ion pairing. Values of ΔG d° for pairs with TBA + give some doubt that it is a “weakly-coordinating cation.” Computations with DFT methods were moderately successful at describing the ion paring energies.« less

Low molecular weight salts combined with fluorinated solvents for electrolytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tikhonov, Konstantin; Yip, Ka Ki; Lin, Tzu-Yuan

2015-11-10

Provided are electrochemical cells and electrolytes used to build such cells. An electrolyte includes at least one salt having a molecular weight less than about 250. Such salts allow forming electrolytes with higher salt concentrations and ensure high conductivity and ion transport in these electrolytes. The low molecular weight salt may have a concentration of at least about 0.5M and may be combined with one or more other salts, such as linear and cyclic imide salts and/or methide salts. The concentration of these additional salts may be less than that of the low molecular weight salt, in some embodiments, twicemore » less. The additional salts may have a molecular weight greater than about 250. The electrolyte may also include one or more fluorinated solvents and may be capable of maintaining single phase solutions at between about -30.degree. C. to about 80.degree. C.« less

Graphene quantum dots as the electrolyte for solid state supercapacitors

PubMed Central

Zhang, Su; Li, Yutong; Song, Huaihe; Chen, Xiaohong; Zhou, Jisheng; Hong, Song; Huang, Minglu

2016-01-01

We propose that graphene quantum dots (GQDs) with a sufficient number of acidic oxygen-bearing functional groups such as -COOH and -OH can serve as solution- and solid- type electrolytes for supercapacitors. Moreover, we found that the ionic conductivity and ion-donating ability of the GQDs could be markedly improved by simply neutralizing their acidic functional groups by using KOH. These neutralized GQDs as the solution- or solid-type electrolytes greatly enhanced the capacitive performance and rate capability of the supercapacitors. The reason for the enhancement can be ascribed to the fully ionization of the weak acidic oxygen-bearing functional groups after neutralization. PMID:26763275

Effective screening length and quasiuniversality for the restricted primitive model of an electrolyte solution.

PubMed

Janecek, Jirí; Netz, Roland R

2009-02-21

Monte Carlo simulations for the restricted primitive model of an electrolyte solution above the critical temperature are performed at a wide range of concentrations and temperatures. Thermodynamic properties such as internal energy, osmotic coefficient, activity coefficient, as well as spatial correlation functions are determined. These observables are used to investigate whether quasiuniversality in terms of an effective screening length exists, similar to the role played by the effective electron mass in solid-state physics. To that end, an effective screening length is extracted from the asymptotic behavior of the Fourier-transformed charge-correlation function and plugged into the Debye-Huckel limiting expressions for various thermodynamic properties. Comparison with numerical results is favorable, suggesting that correlation and other effects not captured on the Debye-Huckel limiting level can be successfully incorporated by a single effective parameter while keeping the functional form of Debye-Huckel expressions. We also compare different methods to determine mean ionic activity coefficient in molecular simulations and check the internal consistency of the numerical data.

Electrochemically Controlled Ion-exchange Property of Carbon Nanotubes/Polypyrrole Nanocomposite in Various Electrolyte Solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Daiwon; Zhu, Chengzhou; Fu, Shaofang

2016-09-15

The electrochemically controlled ion-exchange properties of multi-wall carbon nanotube (MWNT)/electronically conductive polypyrrole (PPy) polymer composite in the various electrolyte solutions have been investigated. The ion-exchange behavior, rate and capacity of the electrochemically deposited polypyrrole with and without carbon nanotube (CNT) were compared and characterized using cyclic voltammetry (CV), chronoamperometry (CA), electrochemical quartz crystal microbalance (EQCM), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). It has been found that the presence of carbon nanotube backbone resulted in improvement in ion-exchange rate, stability of polypyrrole, and higher anion loading capacity per PPy due to higher surface area, electronic conductivity, porous structuremore » of thin film, and thinner film thickness providing shorter diffusion path. Chronoamperometric studies show that electrically switched anion exchange could be completed more than 10 times faster than pure PPy thin film. The anion selectivity of CNT/PPy film is demonstrated using X-ray photoelectron spectroscopy (XPS).« less

Polysulfide Speciation in the Bulk Electrolyte of a Lithium Sulfur Battery

DOE Office of Scientific and Technical Information (OSTI.GOV)

McBrayer, Josefine D.; Beechem, Thomas E.; Perdue, Brian R.

In situ Raman microscopy was used to study polysulfide speciation in the bulk ether electrolyte during the discharge and charge of a Li-S electrochemical cell to assess the complex interplay between chemical and electrochemical reactions in solution. During discharge, long chain polysulfides and the S 3 - radical appear in the electrolyte at 2.4 V indicating a rapid equilibrium of the dissociation reaction to form S 3 -. When charging, however, an increase in the concentration of all polysulfide species was observed. This highlights the importance of the electrolyte to sulfur ratio and suggests a loss in the useful sulfurmore » inventory from the cathode to the electrolyte.« less

Polysulfide Speciation in the Bulk Electrolyte of a Lithium Sulfur Battery

DOE PAGES

McBrayer, Josefine D.; Beechem, Thomas E.; Perdue, Brian R.; ...

2018-03-23

In situ Raman microscopy was used to study polysulfide speciation in the bulk ether electrolyte during the discharge and charge of a Li-S electrochemical cell to assess the complex interplay between chemical and electrochemical reactions in solution. During discharge, long chain polysulfides and the S 3 - radical appear in the electrolyte at 2.4 V indicating a rapid equilibrium of the dissociation reaction to form S 3 -. When charging, however, an increase in the concentration of all polysulfide species was observed. This highlights the importance of the electrolyte to sulfur ratio and suggests a loss in the useful sulfurmore » inventory from the cathode to the electrolyte.« less

Molecular dynamics simulations of the electrical double layer on smectite surfaces contacting concentrated mixed electrolyte (NaCl-CaCl2) solutions.

PubMed

Bourg, Ian C; Sposito, Garrison

2011-08-15

We report new molecular dynamics results elucidating the structure of the electrical double layer (EDL) on smectite surfaces contacting mixed NaCl-CaCl(2) electrolyte solutions in the range of concentrations relevant to pore waters in geologic repositories for CO(2) or high-level radioactive waste (0.34-1.83 mol(c) dm(-3)). Our results confirm the existence of three distinct ion adsorption planes (0-, β-, and d-planes), often assumed in EDL models, but with two important qualifications: (1) the location of the β- and d-planes are independent of ionic strength or ion type and (2) "indifferent electrolyte" ions can occupy all three planes. Charge inversion occurred in the diffuse ion swarm because of the affinity of the clay surface for CaCl(+) ion pairs. Therefore, at concentrations ≥0.34 mol(c) dm(-3), properties arising from long-range electrostatics at interfaces (electrophoresis, electro-osmosis, co-ion exclusion, colloidal aggregation) will not be correctly predicted by most EDL models. Co-ion exclusion, typically neglected by surface speciation models, balanced a large part of the clay mineral structural charge in the more concentrated solutions. Water molecules and ions diffused relatively rapidly even in the first statistical water monolayer, contradicting reports of rigid "ice-like" structures for water on clay mineral surfaces. Published by Elsevier Inc.

Tolerance, effectiveness, and acceptability of sulfate-free electrolyte lavage solution for colon cleaning before colonoscopy.

PubMed

Raymond, J M; Beyssac, R; Capdenat, E; Pineau, C H; Kerjean, A; Saux, M C; Couzigou, P; Amouretti, M

1996-09-01

The unpleasant taste of the solution used for preparation before colonoscopy may limit patients' compliance with the procedure. However, the published results concerning the acceptability of sulfate-free electrolyte lavage solution (SF-ELS) for colon cleansing before colonoscopy are conflicting. The aim of this study was to compare SF-ELS with the standard polyethylene glycol (PEG) solution with regard to tolerance, effectiveness, and acceptability. In the first part of the study, 24 patients were assigned to receive either one liter of SF-ELS or one liter of the standard PEG solution. After two hours, the patients had to choose two further liters (of either the first or second solution), and preparation for colonoscopy was completed. In the second part, fifty further patients were randomized into two groups: 25 patients received four liters of standard solution, and 25 patients received four liters of SF-ELS. The patients' opinions regarding the preparation and their willingness to repeat the use of the same preparation were recorded by questionnaire. The quality of the colon preparation was assessed by the endoscopists. Seventeen patients (71%; P < 0.05) preferred SF-ELS. The compliance rate in the two groups was 96%, and the frequency of occurrence of adverse effects was also similar. Colonoscopy was completed in 24 of the 25 patients in the SF-ELS group and 22 of the 25 patients in the standard PEG group (the difference was not significant). Visualization of the mucosa in the areas explored was perfect in 20 of the 25 patients in the SF-ELS group and in 17 of the 25 patients in the PEG group (not significant). Patients had a significant preference for SF-ELS. Eighteen of the 25 patients in the SF-ELS group were willing to accept the same preparation for a further colonoscopy, compared with 11 of the 25 in the other group (P < 0.05). Improving the acceptability of colonic preparation before colonoscopy could improve patients' compliance and the quality of the

Electrolyte creepage barrier for liquid electrolyte fuel cells

DOEpatents

Li, Jian [Alberta, CA; Farooque, Mohammad [Danbury, CT; Yuh, Chao-Yi [New Milford, CT

2008-01-22

A dielectric assembly for electrically insulating a manifold or other component from a liquid electrolyte fuel cell stack wherein the dielectric assembly includes a substantially impermeable dielectric member over which electrolyte is able to flow and a barrier adjacent the dielectric member and having a porosity of less than 50% and greater than 10% so that the barrier is able to measurably absorb and chemically react with the liquid electrolyte flowing on the dielectric member to form solid products which are stable in the liquid electrolyte. In this way, the barrier inhibits flow or creepage of electrolyte from the dielectric member to the manifold or component to be electrically insulated from the fuel cell stack by the dielectric assembly.

Stable dye-sensitized solar cells based on a gel electrolyte with ethyl cellulose as the gelator

NASA Astrophysics Data System (ADS)

Vasei, Maryam; Tajabadi, Fariba; Jabbari, Ali; Taghavinia, Nima

2015-09-01

A simple gelating process is developed for the conventional acetonitrile-based electrolyte of dye solar cells, based on ethyl cellulose as the gelator. The electrolyte becomes quasi-solid-state upon addition of an ethanolic solution of ethyl cellulose to the conventional acetonitrile-based liquid electrolyte. The photovoltaic conversion efficiency with the new gel electrolyte is only slightly lower than with the liquid electrolyte, e.g., 6.5 % for liquid electrolyte versus 5.9 % for gel electrolyte with 5.8 wt% added ethyl cellulose. Electrolyte gelation has small effect on the ionic diffusion coefficient of iodide, and the devices are remarkably stable for at least 550 h under irradiation at 55 °C.

Electrical conductivity of electrolytes applicable to natural waters from 0 to 100 degrees C

USGS Publications Warehouse

McCleskey, R. Blaine

2011-01-01

The electrical conductivities of 34 electrolyte solutions found in natural waters ranging from (10-4 to 1) mol•kg-1 in concentration and from (5 to 90) °C have been determined. High-quality electrical conductivity data for numerous electrolytes exist in the scientific literature, but the data do not span the concentration or temperature ranges of many electrolytes in natural waters. Methods for calculating the electrical conductivities of natural waters have incorporated these data from the literature, and as a result these methods cannot be used to reliably calculate the electrical conductivity over a large enough range of temperature and concentration. For the single-electrolyte solutions, empirical equations were developed that relate electrical conductivity to temperature and molality. For the 942 molar conductivity determinations for single electrolytes from this study, the mean relative difference between the calculated and measured values was 0.1 %. The calculated molar conductivity was compared to literature data, and the mean relative difference for 1978 measurements was 0.2 %. These data provide an improved basis for calculating electrical conductivity for most natural waters.

Randomised clinical trial: Polyethylene glycol 3350 with sports drink vs. polyethylene glycol with electrolyte solution as purgatives for colonoscopy--the incidence of hyponatraemia.

PubMed

Matro, R; Daskalakis, C; Negoianu, D; Katz, L; Henry, C; Share, M; Kastenberg, D

2014-09-01

Polyethylene glycol 3350 plus sports drink (PEG-SD) is a hypo-osmotic purgative commonly used for colonoscopy, though little safety data are available. To evaluate the effect of PEG-SD on serum sodium (Na) and other electrolytes compared with PEG-electrolyte solution (PEG-ELS). We performed a single center, prospective, randomised, investigator-blind comparison of PEG-ELS to PEG-SD in out-patients undergoing colonoscopy. Laboratories were obtained at baseline and immediately before and after colonoscopy. The primary endpoint was development of hyponatraemia (Na <135 mmol/L) the day of colonoscopy. Changes in electrolyte levels were computed as the difference between the lowest value on the day of colonoscopy and baseline. Purgative tolerance and efficacy were assessed. A total of 389 patients were randomised; 364 took purgative and had baseline and day of colonoscopy labs (180 PEG-SD, 184 PEG-ELS). The groups were well matched except for a higher fraction of women and Blacks in PEG-ELS. Seven patients (3.9%) in PEG-SD and four patients (2.2%) in PEG-ELS developed hyponatraemia (OR = 1.82, 95% CI: 0.45-8.62, P = 0.376). Changes in electrolytes from baseline were small but significantly worse with PEG-SD for sodium, potassium and chloride (P = 0.001, 0.012, 0.001, respectively). Preparation completion, adverse events, and overall colon cleansing were similar between the groups, but PEG-ELS had more excellent preparations (52% vs. 30%; P = 0.001). Greater, but very modest, electrolyte changes occur with PEG-SD. Hyponatraemia is infrequent with both purgatives. A significant increase in hyponatraemia was not identified for PEG-SD vs. PEG-ELS, but the sample size may have been inadequate to identify a small, but clinically important difference. ClinicalTrials.gov identifier NCT01299779. © 2014 John Wiley & Sons Ltd.

Acid-base behavior of the gaspeite (NiCO3(s)) surface in NaCl solutions.

PubMed

Villegas-Jiménez, Adrián; Mucci, Alfonso; Pokrovsky, Oleg S; Schott, Jacques

2010-08-03

Gaspeite is a low reactivity, rhombohedral carbonate mineral and a suitable surrogate to investigate the surface properties of other more ubiquitous carbonate minerals, such as calcite, in aqueous solutions. In this study, the acid-base properties of the gaspeite surface were investigated over a pH range of 5 to 10 in NaCl solutions (0.001, 0.01, and 0.1 M) at near ambient conditions (25 +/- 3 degrees C and 1 atm) by means of conventional acidimetric and alkalimetric titration techniques and microelectrophoresis. Over the entire experimental pH range, surface protonation and electrokinetic mobility are strongly affected by the background electrolyte, leading to a significant decrease of the pH of zero net proton charge (PZNPC) and the pH of isoelectric point (pH(iep)) at increasing NaCl concentrations. This challenges the conventional idea that carbonate mineral surfaces are chemically inert to background electrolyte ions. Multiple sets of surface complexation reactions (i.e., ionization and ion adsorption) were formulated within the framework of three electrostatic models (CCM, BSM, and TLM) and their ability to simulate proton adsorption and electrokinetic data was evaluated. A one-site, 3-pK, constant capacitance surface complexation model (SCM) reproduces the proton adsorption data at all ionic strengths and qualitatively predicts the electrokinetic behavior of gaspeite suspensions. Nevertheless, the strong ionic strength dependence exhibited by the optimized SCM parameters reveals that the influence of the background electrolyte on the surface reactivity of gaspeite is not fully accounted for by conventional electrostatic and surface complexation models and suggests that future refinements to the underlying theories are warranted.

Advanced Proton Conducting Polymer Electrolytes for Electrochemical Capacitors

NASA Astrophysics Data System (ADS)

Gao, Han

Research on solid electrochemical energy storage devices aims to provide high performance, low cost, and safe operation solutions for emerging applications from flexible consumer electronics to microelectronics. Polymer electrolytes, minimizing device sealing and liquid electrolyte leakage, are key enablers for these next-generation technologies. In this thesis, a novel proton-conducing polymer electrolyte system has been developed using heteropolyacids (HPAs) and polyvinyl alcohol for electrochemical capacitors. A thorough understanding of proton conduction mechanisms of HPAs together with the interactions among HPAs, additives, and polymer framework has been developed. Structure and chemical bonding of the electrolytes have been studied extensively to identify and elucidate key attributes affecting the electrolyte properties. Numerical models describing the proton conduction mechanism have been applied to differentiate those attributes. The performance optimization of the polymer electrolytes through additives, polymer structural modifications, and synthesis of alternative HPAs has achieved several important milestones, including: (a) high proton mobility and proton density; (b) good ion accessibility at electrode/electrolyte interface; (c) wide electrochemical stability window; and (d) good environmental stability. Specifically, high proton mobility has been addressed by cross-linking the polymer framework to improve the water storage capability at normal-to-high humidity conditions (e.g. 50-80% RH) as well as by incorporating nano-fillers to enhance the water retention at normal humidity levels (e.g. 30-60% RH). High proton density has been reached by utilizing additional proton donors (i.e. acidic plasticizers) and by developing different HPAs. Good ion accessibility has been achieved through addition of plasticizers. Electrochemical stability window of the electrolyte system has also been investigated and expanded by utilizing HPAs with different heteroatoms

Bridging Redox Species-Coated Graphene Oxide Sheets to Electrode for Extending Battery Life Using Nanocomposite Electrolyte.

PubMed

Huang, Yi Fu; Ruan, Wen Hong; Lin, Dong Ling; Zhang, Ming Qiu

2017-01-11

Substituting conventional electrolyte for redox electrolyte has provided a new intriguing method for extending battery life. The efficiency of utilizing the contained redox species (RS) in the redox electrolyte can benefit from increasing the specific surface area of battery electrodes from the electrode side of the electrode-electrolyte interface, but is not limited to that. Herein, a new strategy using nanocomposite electrolyte is proposed to enlarge the interface with the aid of nanoinclusions from the electrolyte side. To do this, graphene oxide (GO) sheets are first dispersed in the electrolyte solution of tungstosilicic salt/lithium sulfate/poly(vinyl alcohol) (SiWLi/Li 2 SO 4 /PVA), and then the sheets are bridged to electrode, after casting and evaporating the solution on the electrode surface. By applying in situ conductive atomic force microscopy and Raman spectra, it is confirmed that the GO sheets doped with RS of SiWLi/Li 2 SO 4 can be bridged and electrically reduced as an extended electrode-electrolyte interface. As a result, the RS-coated GO sheets bridged to LiTi 2 (PO 4 ) 3 //LiMn 2 O 4 battery electrodes are found to deliver extra energy capacity (∼30 mAh/g) with excellent electrochemical cycling stability, which successfully extends the battery life by over 50%.

First-principles molecular dynamics simulation study on electrolytes for use in redox flow battery

NASA Astrophysics Data System (ADS)

Choe, Yoong-Kee; Tsuchida, Eiji; Tokuda, Kazuya; Ootsuka, Jun; Saito, Yoshihiro; Masuno, Atsunobu; Inoue, Hiroyuki

2017-11-01

Results of first-principles molecular dynamics simulations carried out to investigate structural aspects of electrolytes for use in a redox flow battery are reported. The electrolytes studied here are aqueous sulfuric acid solutions where its property is of importance for dissolving redox couples in redox flow battery. The simulation results indicate that structural features of the acid solutions depend on the concentration of sulfuric acid. Such dependency arises from increase of proton dissociation from sulfuric acid.

Chloride supporting electrolytes for all-vanadium redox flow batteries.

PubMed

Kim, Soowhan; Vijayakumar, M; Wang, Wei; Zhang, Jianlu; Chen, Baowei; Nie, Zimin; Chen, Feng; Hu, Jianzhi; Li, Liyu; Yang, Zhenguo

2011-10-28

This paper examines vanadium chloride solutions as electrolytes for an all-vanadium redox flow battery. The chloride solutions were capable of dissolving more than 2.3 M vanadium at varied valence states and remained stable at 0-50 °C. The improved stability appeared due to the formation of a vanadium dinuclear [V(2)O(3)·4H(2)O](4+) or a dinuclear-chloro complex [V(2)O(3)Cl·3H(2)O](3+) in the solutions over a wide temperature range. The all-vanadium redox flow batteries with the chloride electrolytes demonstrated excellent reversibility and fairly high efficiencies. Only negligible, if any, gas evolution was observed. The improved energy capacity and good performance, along with the ease in heat management, would lead to substantial reduction in capital cost and life-cycle cost, making the vanadium chloride redox flow battery a promising candidate for stationary applications. This journal is © the Owner Societies 2011

Electrolytes and thermoregulation

NASA Technical Reports Server (NTRS)

Nielsen, B.; Greenleaf, J. E.

1977-01-01

The influence of ions on temperature is studied for cases where the changes in ionic concentrations are induced by direct infusion or injection of electrolyte solutions into the cerebral ventricles or into specific areas of brain tissue; intravenous infusion or injection; eating food or drinking solutions of different ionic composition; and heat or exercise dehydration. It is shown that introduction of Na(+) and Ca(++) into the cerebral ventricles or into the venous system affects temperature regulation. It appears that the specific action of these ions is different from their osmotic effects. It is unlikely that their action is localized to the thermoregulatory centers in the brain. The infusion experiments demonstrate that the changes in sodium balance occurring during exercise and heat stress are large enough to affect sweat gland function and vasomotor activity.

Theoretical study on the sound absorption of electrolytic solutions. II. Assignments of relaxations.

PubMed

Yamaguchi, T; Matsuoka, T; Koda, S

2007-08-14

The theory on the ultrasonic absorption spectrum of electrolytic solutions recently proposed by us is applied to the model system that resembles to the aqueous solution of MgSO4. The charges on ions are reduced to +/-1.5e in order to obtain the equilibrium structure by the integral equation theory. The theory reproduces the existence of two relaxations around 100 kHz and 1 GHz. The physical origin of the relaxation is analyzed based on the theoretical expression. The slower relaxation is shown to originate in the formation of contact ion pair, in harmony with the conventional assignment. The amplitude of this relaxation agrees with the experimental one fairly well. The absorption cross section is a weakly increasing function of the concentration of the salt in theory, whereas it depends little on the concentration in experiment, which is ascribed to the weaker association of the pair in the theory. The deviation from the Debye relaxation is found for the faster process, and the concentration dependence is small. The analysis shows that this relaxation stems from the coupling between the pressure and the long-range concentration fluctuation, and the concentration independence and the non-Debye relaxation are explained based on the theoretical analysis. In particular, the theory demonstrates that this process has the t(-3/2) tail in the time domain, which is confirmed by numerical calculation. The deviation of the theoretical relaxation amplitude from the experimental one is elucidated in terms of the theoretical expression of the coefficient.

New electrolyte may increase life of polarographic oxygen sensors

NASA Technical Reports Server (NTRS)

Albright, C. F.

1967-01-01

Electrolyte increases life on oxygen sensors in a polarograph used for measuring the partial pressure of oxygen in a gas mixture. It consists of a solution of lithium chloride, dimethyl acetamide and water.

In Situ Raman Spectroscopic Studies on Concentration of Electrolyte Salt in Lithium-Ion Batteries by Using Ultrafine Multifiber Probes.

PubMed

Yamanaka, Toshiro; Nakagawa, Hiroe; Tsubouchi, Shigetaka; Domi, Yasuhiro; Doi, Takayuki; Abe, Takeshi; Ogumi, Zempachi

2017-03-09

Lithium-ion batteries have attracted considerable attention due to their high power density. The change in concentration of salt in the electrolyte solution in lithium-ion batteries during operation causes serious degradation of battery performance. Herein, a new method of in situ Raman spectroscopy with ultrafine multifiber probes was developed to simultaneously study the concentrations of ions at several different positions in the electrolyte solution in deep narrow spaces between the electrodes in batteries. The total amount of ions in the electrolyte solution clearly changed during operation due to the low permeability of the solid-electrolyte interphase (SEI) at the anode for Li + permeation. The permeability, which is a key factor to achieve high battery performance, was improved (enhanced) by adding film-forming additives to the electrolyte solution to modify the properties of the SEI. The results provide important information for understanding and predicting phenomena occurring in a battery and for designing a superior battery. The present method is useful for analysis in deep narrow spaces in other electrochemical devices, such as capacitors. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Stable electrolyte for high voltage electrochemical double-layer capacitors

DOE PAGES

Ruther, Rose E.; Sun, Che -Nan; Holliday, Adam; ...

2016-12-28

A simple electrolyte consisting of NaPF 6 salt in 1,2-dimethoxyethane (DME) can extend the voltage window of electric double-layer capacitors (EDLCs) to >3.5 V. DME does not passivate carbon electrodes at very negative potentials (near Na/Na +), extending the practical voltage window by about 1.0 V compared to standard, non-aqueous electrolytes based on acetonitrile. The voltage window is demonstrated in two- and three-electrode cells using a combination of electrochemical impedance spectroscopy (EIS), charge-discharge cycling, and measurements of leakage current. DME-based electrolytes cannot match the high conductivity of acetonitrile solutions, but they can satisfy applications that demand high energy density atmore » moderate power. The conductivity of NaPF 6 in DME is comparable to commercial lithium-ion battery electrolytes and superior to most ionic liquids. Lastly, factors that limit the voltage window and EDLC energy density are discussed, and strategies to further boost energy density are proposed.« less

Electrolytes including fluorinated solvents for use in electrochemical cells

DOEpatents

Tikhonov, Konstantin; Yip, Ka Ki; Lin, Tzu-Yuan

2015-07-07

Provided are electrochemical cells and electrolytes used to build such cells. The electrolytes include ion-supplying salts and fluorinated solvents capable of maintaining single phase solutions with the salts at between about -30.degree. C. to about 80.degree. C. The fluorinated solvents, such as fluorinated carbonates, fluorinated esters, and fluorinated esters, are less flammable than their non-fluorinated counterparts and increase safety characteristics of cells containing these solvents. The amount of fluorinated solvents in electrolytes may be between about 30% and 80% by weight not accounting weight of the salts. Fluorinated salts, such as fluoroalkyl-substituted LiPF.sub.6, fluoroalkyl-substituted LiBF.sub.4 salts, linear and cyclic imide salts as well as methide salts including fluorinated alkyl groups, may be used due to their solubility in the fluorinated solvents. In some embodiments, the electrolyte may also include a flame retardant, such as a phosphazene or, more specifically, a cyclic phosphazene and/or one or more ionic liquids.

Thermally responsive polymer electrolytes for inherently safe electrochemical energy storage

NASA Astrophysics Data System (ADS)

Kelly, Jesse C.

Electrochemical double layer capacitors (EDLCs), supercapacitors and Li-ion batteries have emerged as premier candidates to meet the rising demands in energy storage; however, such systems are limited by thermal hazards, thermal runaway, fires and explosions, all of which become increasingly more dangerous in large-format devices. To prevent such scenarios, thermally-responsive polymer electrolytes (RPEs) that alter properties in electrochemical energy storage devices were designed and tested. These RPEs will be used to limit or halt device operation when temperatures increase beyond a predetermined threshold, therefore limiting further heating. The development of these responsive systems will offer an inherent safety mechanism in electrochemical energy storage devices, while preserving the performance, lifetimes, and versatility that large-format systems require. Initial work focused on the development of a model system that demonstrated the concept of RPEs in an electrochemical device. Aqueous electrolyte solutions of polymers exhibiting properties that change in response to temperature were developed for applications in EDLCs and supercapacitors. These "smart materials" provide a means to control electrochemical systems where polymer phase separation at high temperatures affects electrolyte properties and inhibits device performance. Aqueous RPEs were synthesized using N-isopropylacrylamide, which governs the thermal properties, and fractions of acrylic acid or vinyl sulfonic acids, which provide ions to the solution. The molecular properties of these aqueous RPEs, specifically the ionic composition, were shown to influence the temperature-dependent electrolyte properties and the extent to which these electrolytes control the energy storage characteristics of a supercapacitor device. Materials with high ionic content provided the highest room temperature conductivity and electrochemical activity; however, RPEs with low ionic content provided the highest "on

Effects of fluid, electrolyte and substrate ingestion on endurance capacity.

PubMed

Maughan, R J; Fenn, C E; Leiper, J B

1989-01-01

The availability of carbohydrate (CHO) as a substrate for the exercising muscles is known to be a limiting factor in the performance of prolonged cycle exercise, and provision of exogenous CHO in the form of glucose can increase endurance capacity. The present study examined the effects of ingestion of fluids and of CHO in different forms on exercise performance. Six male volunteers exercised to exhaustion on a cycle ergometer at a workload which required approximately 70% of Vo2max. After one preliminary trial, subjects performed this exercise test on six occasions, one week apart. Immediately before exercise, and at 10-min intervals throughout, subjects ingested 100 ml of one of the following: control (no drink), water, glucose syrup, fructose syrup, glucose-fructose syrup or a dilute glucose-electrolyte solution. Each of the syrup solutions contained approximately 36 g CHO per 100 ml; the isotonic glucose-electrolyte solution contained 4 g glucose per 100 ml. A randomised Latin square order of administration of trials was employed. Expired air samples for determination of Vo2, respiratory exchange ratio and rate of CHO oxidation were collected at 15-min intervals. Venous blood samples were obtained before and after exercise. Subjects drinking the isotonic glucose-electrolyte solution exercised longer (90.8 (12.4) min, mean (SEM] than on the control test (70.2 (8.3) min; p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Coupling between electrolyte and organic semiconductor in electrolyte-gated organic field effect transistors (Conference Presentation)

NASA Astrophysics Data System (ADS)

Biscarini, Fabio; Di Lauro, Michele; Berto, Marcello; Bortolotti, Carlo A.; Geerts, Yves H.; Vuillaume, Dominique

2016-11-01

Organic field effect transistors (OFET) operated in aqueous environments are emerging as ultra-sensitive biosensors and transducers of electrical and electrochemical signals from a biological environment. Their applications range from detection of biomarkers in bodily fluids to implants for bidirectional communication with the central nervous system. They can be used in diagnostics, advanced treatments and theranostics. Several OFET layouts have been demonstrated to be effective in aqueous operations, which are distinguished either by their architecture or by the respective mechanism of doping by the ions in the electrolyte solution. In this work we discuss the unification of the seemingly different architectures, such as electrolyte-gated OFET (EGOFET), organic electrochemical transistor (OECT) and dual-gate ion-sensing FET. We first demonstrate that these architectures give rise to the frequency-dependent response of a synapstor (synapse-like transistor), with enhanced or depressed modulation of the output current depending on the frequency of the time-dependent gate voltage. This behavior that was reported for OFETs with embedded metal nanoparticles shows the existence of a capacitive coupling through an equivalent network of RC elements. Upon the systematic change of ions in the electrolyte and the morphology of the charge transport layer, we show how the time scale of the synapstor is changed. We finally show how the substrate plays effectively the role of a second bottom gate, whose potential is actually fixed by the pH/composition of the electrolyte and the gate voltage applied.

Influence of Silicate Concentration in Electrolyte on the Growth and Performance of Plasma Electrolytic Oxidation Coatings Prepared on Low Carbon Steel

NASA Astrophysics Data System (ADS)

Yang, Wenbin; Peng, Zhenjun; Liu, Baixing; Liu, Weimin; Liang, Jun

2018-04-01

Plasma electrolytic oxidation (PEO) coatings were prepared on low carbon steel from electrolytes with different silicate concentrations. The microstructure, elemental and phase compositions of the PEO coatings were analyzed by scanning electron microscope, energy-dispersive spectrometer, and x-ray diffraction, respectively. The adhesion of PEO coatings with low carbon steel substrate was qualitatively examined by thermal shock tests. The tribological properties were evaluated by a reciprocating tribometer sliding against a Si3N4 ceramic ball. The corrosion behaviors of PEO coatings were investigated in 3.5 wt.% NaCl solution by electrochemical impedance spectra and potentiodynamic polarization. Results indicated that all the PEO coatings were comprised of amorphous SiO2 and Fe-containing oxides; however, the silicate concentration in electrolyte showed significant influence on the growth and the performance of PEO coatings. The PEO coating prepared from the electrolyte with silicate concentration of 30 g/L had the highest Fe content because the substrate was more readily oxidized and showed a dense structure, resulting in the best comprehensive performance of adhesion, wear resistance, and corrosion resistance.

Influence of Silicate Concentration in Electrolyte on the Growth and Performance of Plasma Electrolytic Oxidation Coatings Prepared on Low Carbon Steel

NASA Astrophysics Data System (ADS)

Yang, Wenbin; Peng, Zhenjun; Liu, Baixing; Liu, Weimin; Liang, Jun

2018-05-01

Plasma electrolytic oxidation (PEO) coatings were prepared on low carbon steel from electrolytes with different silicate concentrations. The microstructure, elemental and phase compositions of the PEO coatings were analyzed by scanning electron microscope, energy-dispersive spectrometer, and x-ray diffraction, respectively. The adhesion of PEO coatings with low carbon steel substrate was qualitatively examined by thermal shock tests. The tribological properties were evaluated by a reciprocating tribometer sliding against a Si3N4 ceramic ball. The corrosion behaviors of PEO coatings were investigated in 3.5 wt.% NaCl solution by electrochemical impedance spectra and potentiodynamic polarization. Results indicated that all the PEO coatings were comprised of amorphous SiO2 and Fe-containing oxides; however, the silicate concentration in electrolyte showed significant influence on the growth and the performance of PEO coatings. The PEO coating prepared from the electrolyte with silicate concentration of 30 g/L had the highest Fe content because the substrate was more readily oxidized and showed a dense structure, resulting in the best comprehensive performance of adhesion, wear resistance, and corrosion resistance.

Cryoelectrolysis—electrolytic processes in a frozen physiological saline medium

PubMed Central

Lugnani, Franco; Macchioro, Matteo

2017-01-01

Background Cryoelectrolysis is a new minimally invasive tissue ablation surgical technique that combines the ablation techniques of electrolytic ablation with cryosurgery. The goal of this study is to examine the hypothesis that electrolysis can take place in a frozen aqueous saline solution. Method To examine the hypothesis we performed a cryoelectrolytic ablation protocol in which electrolysis and cryosurgery are delivered simultaneously in a tissue simulant made of physiological saline gel with a pH dye. We measured current flow, voltage and extents of freezing and pH dye staining. Results Using optical measurements and measurements of currents, we have shown that electrolysis can occur in frozen physiological saline, at high subzero freezing temperatures, above the eutectic temperature of the frozen salt solution. It was observed that electrolysis occurs when the tissue resides at high subzero temperatures during the freezing stage and essentially throughout the entire thawing stage. We also found that during thawing, the frozen lesion temperature raises rapidly to high subfreezing values and remains at those values throughout the thawing stage. Substantial electrolysis occurs during the thawing stage. Another interesting finding is that electro-osmotic flows affect the process of cryoelectrolysis at the anode and cathode, in different ways. Discussion The results showing that electrical current flow and electrolysis occur in frozen saline solutions imply a mechanism involving ionic movement in the fluid concentrated saline solution channels between ice crystals, at high subfreezing temperatures. Temperatures higher than the eutectic are required for the brine to be fluid. The particular pattern of temperature and electrical currents during the thawing stage of frozen tissue, can be explained by the large amounts of energy that must be removed at the outer edge of the frozen lesion because of the solid/liquid phase transformation on that interface. Conclusion

A new method for multicomponent activity coefficients of electrolytes in aqueous atmospheric aerosols

NASA Astrophysics Data System (ADS)

Zaveri, Rahul A.; Easter, Richard C.; Wexler, Anthony S.

2005-01-01

Three-dimensional models of atmospheric inorganic aerosols need accurate and computationally efficient parameterizations of activity coefficients of various electrolytes in multicomponent aqueous solutions. In this paper, we extend the Taylor's series expansion mixing rule used by C. Wagner in 1952 for estimating activity coefficients in dilute alloy solutions to aqueous electrolyte solutions at any concentration. The resulting method, called the multicomponent Taylor expansion method (MTEM), estimates the mean activity coefficient of an electrolyte in a multicomponent solution on the basis of its values in binary solutions of all the electrolytes present in the mixture at the solution water activity aw, assuming aw is equal to the ambient relative humidity. MTEM is applied here for atmospheric aerosol systems containing H+, NH4+, Na+, Ca2+, SO42-, HSO4-, NO3-, and Cl- ions. The aerosol water content is calculated using the Zdanovskii-Stokes-Robinson (ZSR) method. For self-consistency, most of the MTEM and ZSR parameters are derived using the comprehensive Pitzer-Simonson-Clegg model at 298.15 K and are valid for an aw range of 0.2-0.97. Because CaSO4 is sparingly soluble, it is treated as a solid in the model over the entire aw range. MTEM is evaluated for several multicomponent systems representing various continental and marine aerosols and is contrasted against the mixing rule of C. L. Kusik and H. P. Meissner and of L. A. Bromley and the newer approach of S. Metzger and colleagues. Predictions of MTEM are found to be generally within a factor of 0.8-1.25 of the comprehensive Pitzer-Simonson-Clegg model and are shown to be significantly more accurate than predictions of the other three methods. MTEM also yields a noniterative solution of the bisulfate ion dissociation in sulfate-rich systems: a major computational advantage over other ionic-strength-based methods that require an iterative solution. CPU time requirements of MTEM relative to other methods for

[Computer modeling the dependences of the membrane potential for polymeric membrane separated non-homogeneous electrolyte solutions on concentration Rayleigh number].

PubMed

Slezak, Izabella H; Jasik-Slezak, Jolanta; Bilewicz-Wyrozumska, Teresa; Slezak, Andrzej

2006-01-01

On the basis of model equation describing the membrane potential delta psi(s) on concentration Rayleigh number (R(C)), mechanical pressure difference (deltaP), concentration polarization coefficient (zeta s) and ratio concentration of solutions separated by membrane (Ch/Cl), the characteristics delta psi(s) = f(Rc)(delta P, zeta s, Ch/Cl) for steady values of zeta s, R(C) and Ch/Cl in single-membrane system were calculated. In this system neutral and isotropic polymeric membrane oriented in horizontal plane, the non-homogeneous binary electrolytic solutions of various concentrations were separated. Nonhomogeneity of solutions is results from creations of the concentration boundary layers on both sides of the membrane. Calculations were made for the case where on a one side of the membrane aqueous solution of NaCl at steady concentration 10(-3) mol x l(-1) (Cl) was placed and on the other aqueous solutions of NaCl at concentrations from 10(-3) mol x l(-1) to 2 x 10(-2) mol x l(-1) (Ch). Their densities were greater than NaCl solution's at 10(-3) mol x l(-1). It was shown that membrane potential depends on hydrodynamic state of a complex concentration boundary layer-membrane-concentration boundary layer, what is controlled by deltaP, Ch/Cl, Rc and Zeta(s).

Nonequilibrium mechanisms of weak electrolyte electrification under the action of constant voltage

NASA Astrophysics Data System (ADS)

Stishkov, Yu. K.; Chirkov, V. A.

2016-07-01

The formation of space charge in weak electrolytes, specifically in liquid dielectrics, has been considered. An analytical solution is given to a simplified set of Nernst-Planck equations that describe the formation of nonequilibrium recombination layers in weak electrolytes. This approximate analytical solution is compared with computer simulation data for a complete set of Poisson-Nernst-Planck equations. It has been shown that the current passage in weak electrolytes can be described by a single dimensionless parameter that equals the length of a near-electrode recombination layer divided by the width of the interelectrode gap. The formation mechanism and the structure of charged nonequilibrium near-electrode layers in the nonstationary regime have been analyzed for different injection-to-conduction current ratios. It has been found that almost all charge structures encountered in weak dielectrics can be accounted for by the nonequilibrium dissociation-recombination mechanism of space charge formation.

Adsorption Removal of 17β-Estradiol from Water by Rice Straw-Derived Biochar with Special Attention to Pyrolysis Temperature and Background Chemistry.

PubMed

Wang, Xiaohua; Liu, Ni; Liu, Yunguo; Jiang, Luhua; Zeng, Guangming; Tan, Xiaofei; Liu, Shaobo; Yin, Zhihong; Tian, Sirong; Li, Jiang

2017-10-11

Rice straw biochar that produced at three pyrolysis temperatures (400, 500 and 600 °C) were used to investigate the adsorption properties of 17β-estradiol (E2). The biochar samples were characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), elemental analysis and BET surface area measurements. The influences of pyrolysis temperature, E2 concentration, pH, ionic strength, background electrolyte and humic acid were studied. Kinetic and isotherm results illustrated that the adsorption process could be well described by pseudo-second-order and Freundlich models. Experimental results showed that ionic strength had less influence on the adsorption of E2 by 500 and 600 °C rice straw biochar. Further, multivalent ions had positive impact on E2 removal than monovalent ions and the influence of the pyrolysis temperature was unremarkable when background electrolyte existed in solutions. The adsorption capacity of E2 decreased with the pH ranged from 3.0 to 12.0 and the humic acid concentration from 2 to 10 mg L -1 . Electrostatic attractions and π-π interaction were involved in the adsorption mechanisms. Compared to low-temperature biochar, high-temperature biochar exhibited a better adsorption capacity for E2 in aqueous solution, indicated it had a greater potential for E2 pollution control.

Adsorption Removal of 17β-Estradiol from Water by Rice Straw-Derived Biochar with Special Attention to Pyrolysis Temperature and Background Chemistry

PubMed Central

Wang, Xiaohua; Liu, Ni; Liu, Yunguo; Jiang, Luhua; Zeng, Guangming; Tan, Xiaofei; Liu, Shaobo; Yin, Zhihong; Tian, Sirong; Li, Jiang

2017-01-01

Rice straw biochar that produced at three pyrolysis temperatures (400, 500 and 600 °C) were used to investigate the adsorption properties of 17β-estradiol (E2). The biochar samples were characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), elemental analysis and BET surface area measurements. The influences of pyrolysis temperature, E2 concentration, pH, ionic strength, background electrolyte and humic acid were studied. Kinetic and isotherm results illustrated that the adsorption process could be well described by pseudo-second-order and Freundlich models. Experimental results showed that ionic strength had less influence on the adsorption of E2 by 500 and 600 °C rice straw biochar. Further, multivalent ions had positive impact on E2 removal than monovalent ions and the influence of the pyrolysis temperature was unremarkable when background electrolyte existed in solutions. The adsorption capacity of E2 decreased with the pH ranged from 3.0 to 12.0 and the humic acid concentration from 2 to 10 mg L−1. Electrostatic attractions and π-π interaction were involved in the adsorption mechanisms. Compared to low-temperature biochar, high-temperature biochar exhibited a better adsorption capacity for E2 in aqueous solution, indicated it had a greater potential for E2 pollution control. PMID:29019933

Preliminary study of application of Moringa oleifera resin as polymer electrolyte in DSSC solar cells

NASA Astrophysics Data System (ADS)

Saehana, Sahrul; Darsikin, Muslimin

2016-04-01

This study reports the preliminary study of application of Moringa oleifera resin as polymer electrolyte in dye-sensitized solar cell (DSSC). We found that polymer electrolyte membrane was formed by using solution casting methods. It is observed that polymer electrolyte was in elastic form and it is very potential to application as DSSC component. Performance of DSSC which employing Moringa oleifera resin was also observed and photovoltaic effect was found.

Electrolytic decontamination of conductive materials for hazardous waste management

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wedman, D.E.; Martinez, H.E.; Nelson, T.O.

1996-12-31

Electrolytic removal of plutonium and americium from stainless steel and uranium surfaces has been demonstrated. Preliminary experiments were performed on the electrochemically based decontamination of type 304L stainless steel in sodium nitrate solutions to better understand the metal removal effects of varying cur-rent density, pH, and nitrate concentration parameters. Material removal rates and changes in surface morphology under these varying conditions are reported. Experimental results indicate that an electropolishing step before contamination removes surface roughness, thereby simplifying later electrolytic decontamination. Sodium nitrate based electrolytic decontamination produced the most uniform stripping of material at low to intermediate pH and at sodiummore » nitrate concentrations of 200 g L{sup -1} and higher. Stirring was also observed to increase the uniformity of the stripping process.« less

Humic acids as pseudocapacitive electrolyte additive for electrochemical double layer capacitors

NASA Astrophysics Data System (ADS)

Wasiński, Krzysztof; Walkowiak, Mariusz; Lota, Grzegorz

2014-06-01

Novel electrolyte additive for electrochemical capacitors has been reported. It has been demonstrated for the first time that addition of humic acids (HA) to KOH-based electrolyte significantly increases capacitance of symmetrical capacitors with electrodes made of activated carbon. Specific capacitances determined by means of galvanostatic charge/discharge, cyclic voltammetry and electrochemical impedance spectroscopy consistently showed increases for HA concentrations ranging from 2% w/w up to saturated solution with maximum positive effect observed for 5% w/w of the additive. The capacitance increase has been attributed to complex faradaic processes involving oxygen-containing groups of HA molecules. Due to abundant resources, low cost and easy processability the reported solution can find application in electrochemical capacitor technologies.

An aqueous electrolyte of the widest potential window and its superior capability for capacitors.

PubMed

Tomiyasu, Hiroshi; Shikata, Hirokazu; Takao, Koichiro; Asanuma, Noriko; Taruta, Seiichi; Park, Yoon-Yul

2017-03-21

A saturated aqueous solution of sodium perchlorate (SSPAS) was found to be electrochemically superior, because the potential window is remarkably wide to be approximately 3.2 V in terms of a cyclic voltammetry. Such a wide potential window has never been reported in any aqueous solutions, and this finding would be of historical significance for aqueous electrolyte to overcome its weak point that the potential window is narrow. In proof of this fact, the capability of SSPAS was examined for the electrolyte of capacitors. Galvanostatic charge-discharge measurements showed that a graphite-based capacitor containing SSPAS as an electrolyte was stable within 5% deviation for the 10,000 times repetition at the operating voltage of 3.2 V without generating any gas. The SSPAS worked also as a functional electrolyte in the presence of an activated carbon and metal oxides in order to increase an energy density. Indeed, in an asymmetric capacitor containing MnO 2 and Fe 3 O 4 mixtures in the positive and negative electrodes, respectively, the energy density enlarged to be 36.3 Whkg -1 , which belongs to the largest value in capacitors. Similar electrochemical behaviour was also confirmed in saturated aqueous solutions of other alkali and alkaline earth metal perchlorate salts.

An aqueous electrolyte of the widest potential window and its superior capability for capacitors

PubMed Central

Tomiyasu, Hiroshi; Shikata, Hirokazu; Takao, Koichiro; Asanuma, Noriko; Taruta, Seiichi; Park, Yoon-Yul

2017-01-01

A saturated aqueous solution of sodium perchlorate (SSPAS) was found to be electrochemically superior, because the potential window is remarkably wide to be approximately 3.2 V in terms of a cyclic voltammetry. Such a wide potential window has never been reported in any aqueous solutions, and this finding would be of historical significance for aqueous electrolyte to overcome its weak point that the potential window is narrow. In proof of this fact, the capability of SSPAS was examined for the electrolyte of capacitors. Galvanostatic charge-discharge measurements showed that a graphite-based capacitor containing SSPAS as an electrolyte was stable within 5% deviation for the 10,000 times repetition at the operating voltage of 3.2 V without generating any gas. The SSPAS worked also as a functional electrolyte in the presence of an activated carbon and metal oxides in order to increase an energy density. Indeed, in an asymmetric capacitor containing MnO2 and Fe3O4 mixtures in the positive and negative electrodes, respectively, the energy density enlarged to be 36.3 Whkg−1, which belongs to the largest value in capacitors. Similar electrochemical behaviour was also confirmed in saturated aqueous solutions of other alkali and alkaline earth metal perchlorate salts. PMID:28322349

Glass electrolyte composition

DOEpatents

Kucera, Gene H.; Roche, Michael F.

1985-01-01

An ionically conductive glass is disclosed for use as electrolyte in a high temperature electrochemical cell, particularly a cell with sodium anode and sulfur cathode. The glass includes the constituents Na.sub.2 O, ZrO.sub.2, Al.sub.2 O.sub.3 and SiO.sub.2 in selected proportions to be a single phase solid solution substantially free of crystalline regions and undissolved constituents. Other advantageous properties are an ionic conductivity in excess of 2.times.10.sup.-3 (ohm-cm).sup.-1 at 300.degree. C. and a glass transition temperature in excess of 500.degree. C.

Glass electrolyte composition

DOEpatents

Kucera, G.H.; Roche, M.F.

1985-01-08

An ionically conductive glass is disclosed for use as electrolyte in a high temperature electrochemical cell, particularly a cell with sodium anode and sulfur cathode. The glass includes the constituents Na/sub 2/O, ZrO/sub 2/, Al/sub 2/O/sub 3/ and SiO/sub 2/ in selected proportions to be a single phase solid solution substantially free of crystalline regions and undissolved constituents. Other advantageous properties are an ionic conductivity in excess of 2 x 10/sup -3/ (ohm-cm)/sup -1/ at 300/sup 0/C and a glass transition temperature in excess of 500/sup 0/C.

Electrochemical performance of C4O6H4KNa aqueous electrolytes

NASA Astrophysics Data System (ADS)

Zhang, Jianqiang; Song, Senyang; Chen, Yanzheng; Huang, Siyun; Li, Ping; Luo, Heming

2018-06-01

The paper is devoted in the study of the simple method to study the performance of aqueous electrolytes, whereas the custom-made FBNC-700 (FB represents FAC-brown, N represents "nitrogen-self-doped," C represents mesoporous-carbon materials, and 700 represents carbonization temperature.) was utilized as the electrode material, where the C4O6H4KNa solution was utilized as an aqueous electrolyte. The polarization curves was be used in the three-electrode system to conduct the voltage window preliminary selection of the C4O6H4KNa solution, the voltage window was 1.3 V (-0.8 V to 0.5 V). The concentration had minimal effects on the voltage window. The method is faster and more efficient way to study the performance of aqueous electrolytes for supercapacitors. In the 2 M C4O6H4KNa solution, the FBNC-700 displayed a 97 F g-1 specific capacitance at the current density of 0.5 A g-1 in the two-electrodes tests. Also, following 5000 cycles at a current density of 1 A g-1, the FBNC-700 had good stability with 76.22% capacitance retention.

Formulation of ionic liquid electrolyte to expand the voltage window of supercapacitors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van Aken, Katherine L.; Beidaghi, Majid; Gogotsi, Yury

We report an effective method to expand the operating potential window (OPW) of electrochemical capacitors based on formulating the ionic liquid (IL) electrolytes. Moreover, using model electrochemical cells based on two identical onion like carbon (OLC) electrodes and two different IL electrolytes and their mixtures, it was shown that the asymmetric behavior of the electrolyte’s cation and anion toward the two electrodes limits the OPW of the cell and therefore its energy density. Additionally, a general solution to this problem is proposed by formulating the IL electrolyte mixtures to balance the capacitance of electrodes in a symmetric supercapacitor.

Formulation of ionic liquid electrolyte to expand the voltage window of supercapacitors

DOE PAGES

Van Aken, Katherine L.; Beidaghi, Majid; Gogotsi, Yury

2015-03-18

We report an effective method to expand the operating potential window (OPW) of electrochemical capacitors based on formulating the ionic liquid (IL) electrolytes. Moreover, using model electrochemical cells based on two identical onion like carbon (OLC) electrodes and two different IL electrolytes and their mixtures, it was shown that the asymmetric behavior of the electrolyte’s cation and anion toward the two electrodes limits the OPW of the cell and therefore its energy density. Additionally, a general solution to this problem is proposed by formulating the IL electrolyte mixtures to balance the capacitance of electrodes in a symmetric supercapacitor.

Stimulation of colonic motility by oral PEG electrolyte bowel preparation assessed by MRI: comparison of split vs single dose

PubMed Central

Marciani, L; Garsed, K C; Hoad, C L; Fields, A; Fordham, I; Pritchard, S E; Placidi, E; Murray, K; Chaddock, G; Costigan, C; Lam, C; Jalanka-Tuovinen, J; De Vos, W M; Gowland, P A; Spiller, R C

2014-01-01

Background Most methods of assessing colonic motility are poorly acceptable to patients. Magnetic resonance imaging (MRI) can monitor gastrointestinal motility and fluid distributions. We predicted that a dose of oral polyethylene glycol (PEG) and electrolyte solution would increase ileo-colonic inflow and stimulate colonic motility. We aimed to investigate the colonic response to distension by oral PEG electrolyte in healthy volunteers (HVs) and to evaluate the effect of single 2 L vs split (2 × 1 L) dosing. Methods Twelve HVs received a split dose (1 L the evening before and 1 L on the study day) and another 12 HVs a single dose (2 L on the main study day) of PEG electrolyte. They underwent MRI scans, completed symptom questionnaires, and provided stool samples. Outcomes included small bowel water content, ascending colon motility index, and regional colonic volumes. Key Results Small bowel water content increased fourfold from baseline after ingesting both split (p = 0.0010) and single dose (p = 0.0005). The total colonic volume increase from baseline was smaller for the split dose at 35 ± 8% than for the single dose at 102 ± 27%, p = 0.0332. The ascending colon motility index after treatment was twofold higher for the single dose group (p = 0.0103). Conclusions & Inferences Ingestion of 1 and 2 L PEG electrolyte solution caused a rapid increase in the small bowel and colonic volumes and a robust rise in colonic motility. The increase in both volumes and motility was dose dependent. Such a challenge, being well-tolerated, could be a useful way of assessing colonic motility in future studies. PMID:25060551

Separation of tricyclic antidepressants by capillary zone electrophoresis with N,N,N',N'-tetramethyl-1,3-butanediamine (TMBD) as an effective electrolyte additive.

PubMed

Dell'Aquila, Caterina

2002-09-05

Five tricyclic antidepressants (TADs), desipramyne, nortriptyline, imipramine, doxepin and amitriptyline, were separated by using the N,N,N',N'-tetramethyl-1,3-butanediamine (TMBD) as additive in the background electrolyte solution. Because the tricyclic antidepressants are similar in structure, mass and pka values, their separation, by capillary zone electrophoresis, requires the careful manipulation of parameters, such as the pH and the composition of the electrolyte solution. As basic drugs, the TADs interact with the silanol groups on the capillary wall giving rise to peak broadening and asymmetry, non reproducible migration times and failing in selectivity. Different concentrations of TMBD (40, 60, 100 and 150 mM) were used at pH 9.5, but only a 100 mM TMBD allowed a good separation and a high efficiency for all the TADs. At this pH the separation was not possible without additive. This result is due to the reduced electroosmotic flow whose mobility is at a value of 10(-9) m(2) V(-1) s(-1).

Nanoporous polymer electrolyte

DOEpatents

Elliott, Brian [Wheat Ridge, CO; Nguyen, Vinh [Wheat Ridge, CO

2012-04-24

A nanoporous polymer electrolyte and methods for making the polymer electrolyte are disclosed. The polymer electrolyte comprises a crosslinked self-assembly of a polymerizable salt surfactant, wherein the crosslinked self-assembly includes nanopores and wherein the crosslinked self-assembly has a conductivity of at least 1.0.times.10.sup.-6 S/cm at 25.degree. C. The method of making a polymer electrolyte comprises providing a polymerizable salt surfactant. The method further comprises crosslinking the polymerizable salt surfactant to form a nanoporous polymer electrolyte.

Electrolyte vapor condenser

DOEpatents

Sederquist, Richard A.; Szydlowski, Donald F.; Sawyer, Richard D.

1983-01-01

A system is disclosed for removing electrolyte from a fuel cell gas stream. The gas stream containing electrolyte vapor is supercooled utilizing conventional heat exchangers and the thus supercooled gas stream is passed over high surface area passive condensers. The condensed electrolyte is then drained from the condenser and the remainder of the gas stream passed on. The system is particularly useful for electrolytes such as phosphoric acid and molten carbonate, but can be used for other electrolyte cells and simple vapor separation as well.

Electrolyte vapor condenser

DOEpatents

Sederquist, R.A.; Szydlowski, D.F.; Sawyer, R.D.

1983-02-08

A system is disclosed for removing electrolyte from a fuel cell gas stream. The gas stream containing electrolyte vapor is supercooled utilizing conventional heat exchangers and the thus supercooled gas stream is passed over high surface area passive condensers. The condensed electrolyte is then drained from the condenser and the remainder of the gas stream passed on. The system is particularly useful for electrolytes such as phosphoric acid and molten carbonate, but can be used for other electrolyte cells and simple vapor separation as well. 3 figs.

The impact of alkyl sulfate surfactant geometry and electrolyte on the co-adsorption of anionic surfactants with model perfumes at the air-solution interface.

PubMed

Bradbury, Robert; Penfold, Jeffrey; Thomas, Robert K; Tucker, Ian M; Petkov, Jordan T; Jones, Craig

2013-08-01

The impact of surfactant geometry and electrolyte on the co-adsorption of anionic surfactants and model perfumes at the air-solution interface has been studied by neutron reflectivity. The more hydrophobic perfume linalool, competes more favourably for the surface with sodium dodecylsulfate than was previously reported for the anionic surfactant, sodium dodecyl 6-benzenesulfonate. Due to an increase in surface activity of the sodium dodecylsulfate, the addition of electrolyte results in a reduction in the linalool adsorption. Changing the alkyl chain length affects the relative adsorption of linalool and surfactant at the interface. Similar measurements for the different alkyl sulfates and with electrolyte with the more hydrophilic perfume phenyl ethanol, reveal broadly similar trends. Although the relative adsorption of phenyl ethanol with sodium dodecylsulfate is substantially enhanced compared to sodium dodecyl-6-benzenesulfonate the effects are not as significant as was observed with linalool. The variations with alkyl chain geometry show the importance of the hydrophobic interaction between the perfume and surfactant and changes in the packing constraints on the relative adsorption. The results highlight the importance of the specific interaction between the surfactant and perfume, and the surfactant and perfume geometries on the relative adsorption at the interface. Copyright © 2013 Elsevier Inc. All rights reserved.

Lithium-ion conducting electrolyte salts for lithium batteries.

PubMed

Aravindan, Vanchiappan; Gnanaraj, Joe; Madhavi, Srinivasan; Liu, Hua-Kun

2011-12-16

This paper presents an overview of the various types of lithium salts used to conduct Li(+) ions in electrolyte solutions for lithium rechargeable batteries. More emphasis is paid towards lithium salts and their ionic conductivity in conventional solutions, solid-electrolyte interface (SEI) formation towards carbonaceous anodes and the effect of anions on the aluminium current collector. The physicochemical and functional parameters relevant to electrochemical properties, that is, electrochemical stabilities, are also presented. The new types of lithium salts, such as the bis(oxalato)borate (LiBOB), oxalyldifluoroborate (LiODFB) and fluoroalkylphosphate (LiFAP), are described in detail with their appropriate synthesis procedures, possible decomposition mechanism for SEI formation and prospect of using them in future generation lithium-ion batteries. Finally, the state-of-the-art of the system is given and some interesting strategies for the future developments are illustrated. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Submicroporous/microporous and compatible/incompatible multi-functional dual-layer polymer electrolytes and their interfacial characteristics with lithium metal anode

NASA Astrophysics Data System (ADS)

Lee, Young-Gi; Kyhm, Kwangseuk; Choi, Nam-Soon; Ryu, Kwang Sun

A novel multi-functional dual-layer polymer electrolyte was prepared by impregnating the interconnected pores with an ethylene carbonate (EC)/dimethyl carbonate (DMC)/lithium hexafluorophosphate (LiPF 6) solution. An incompatible layer is based on a microporous polyethylene (PE) and a compatible layer, based on a poly(vinylidenefluoride-co-hexafluoropropylene) (P(VdF-co-HFP)) is sub-microporous and compatible with an electrolyte solution. The Li electrode/the dual-layer polymer electrolyte/Li[Ni 0.15Li 0.23M n0.62]O 2 cell showed stable cycle performance under prolonged cycle number. This behavior is due to the enhanced compatibility between the matrix polymer and the liquid electrolytes within the submicroporous compatible layer, which could lead to a controlled Li + deposition on the Li anode surface by forming homegeneous electrolyte zone near the anode.

Non-aqueous electrolyte for lithium-ion battery

DOEpatents

Amine, Khalil; Zhang, Lu; Zhang, Zhengcheng

2016-01-26

A substantially non-aqueous electrolyte solution includes an alkali metal salt, a polar aprotic solvent, and an organophosphorus compound of Formula IA, IB, or IC: ##STR00001## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each independently hydrogen, halogen, alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heterocyclyl, heteroaryl, alkoxy, alkenoxy, alkynoxy, cycloalkoxy, aryloxy, heterocyclyloxy, heteroaryloxy, siloxyl, silyl, or organophosphatyl; R.sup.5 and R.sup.6 are each independently alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heterocyclyl, or heteroaryl; R.sup.7 is ##STR00002## and R.sup.8, R.sup.9 and R.sup.10 are each independently alkyl, cycloalkyl, aryl, heterocyclyl, or heteroaryl; provided that if the organophosphorus compound is of Formula IB, then at least one of R.sup.5, and R.sup.6 are other than hydrogen, alkyl, or alkenyl; and if the organophosphorus compound is of Formula IC, then the electrolyte solution does not include 4-methylene-1,3-dioxolan-2-one or 4,5-dimethylene-1,3-dioxolan-2-one.

A concentrated electrolyte for zinc hexacyanoferrate electrodes in aqueous rechargeable zinc-ion batteries

NASA Astrophysics Data System (ADS)

Kim, D.; Lee, C.; Jeong, S.

2018-01-01

In this study, a concentrated electrolyte was applied in an aqueous rechargeable zinc-ion battery system with a zinc hexacyanoferrate (ZnHCF) electrode to improve the electrochemical performance by changing the hydration number of the zinc ions. To optimize the active material, ZnHCF was synthesized using aqueous solutions of zinc nitrate with three different concentrations. The synthesized materials exhibited some differences in structure, crystallinity, and particle size, as observed by X-ray diffraction and scanning electron microscopy. Subsequently, these well-structured materials were applied in electrochemical tests. A more than two-fold improvement in the charge/discharge capacities was observed when the concentrated electrolyte was used instead of the dilute electrolyte. Additionally, the cycling performance observed in the concentrated electrolyte was superior to that in the dilute electrolyte. This improvement in the electrochemical performance may result from a decrease in the hydration number of the zinc ions in the concentrated electrolyte.

Facile and scalable fabrication of polymer-ceramic composite electrolyte with high ceramic loadings

NASA Astrophysics Data System (ADS)

Pandian, Amaresh Samuthira; Chen, X. Chelsea; Chen, Jihua; Lokitz, Bradley S.; Ruther, Rose E.; Yang, Guang; Lou, Kun; Nanda, Jagjit; Delnick, Frank M.; Dudney, Nancy J.

2018-06-01

Solid state electrolytes are a promising alternative to flammable liquid electrolytes for high-energy lithium battery applications. In this work polymer-ceramic composite electrolyte membrane with high ceramic loading (greater than 60 vol%) is fabricated using a model polymer electrolyte poly(ethylene oxide) + lithium trifluoromethane sulfonate and a lithium-conducting ceramic powder. The effects of processing methods, choice of plasticizer and varying composition on ionic conductivity of the composite electrolyte are thoroughly investigated. The physical, structural and thermal properties of the composites are exhaustively characterized. We demonstrate that aqueous spray coating followed by hot pressing is a scalable and inexpensive technique to obtain composite membranes that are amazingly dense and uniform. The ionic conductivity of composites fabricated using this protocol is at least one order of magnitude higher than those made by dry milling and solution casting. The introduction of tetraethylene glycol dimethyl ether further increases the ionic conductivity. The composite electrolyte's interfacial compatibility with metallic lithium and good cyclability is verified by constructing lithium symmetrical cells. A remarkable Li+ transference number of 0.79 is discovered for the composite electrolyte.

True Anomalous Osmosis in Multi-Solute Model Membrane Systems

PubMed Central

Grim, Eugene; Sollner, Karl

1960-01-01

The transport of liquid across charged porous membranes separating two electrolytic solutions of different composition consists of both a normal and an anomalous osmotic component. Anomalous osmosis does not occur with electroneutral membranes. Thus, with membranes which can be charged and discharged reversibly, normal osmosis can be measured with the membrane in the electroneutral state, and normal together with anomalous osmosis with the membrane in a charged state, the difference between these two effects being the true anomalous osmosis. Data are presented on the osmotic effects across an oxyhemoglobin membrane in the uncharged state at pH 6.75 and in two charged states, positive at pH 4.0 and negative at pH 10.0, in multi-solute systems with 0.2 and 0.4 osmolar solutions of a variety of electrolytes and of glucose against solutions of other solutes of the same, one-half, and twice these osmolarities. In the simpler systems the magnitude of the true anomalous osmosis can be predicted semiquantitatively by reference to appropriate single-solute systems. In isoosmolar systems with two electrolytic solutions the anomalous osmotic flow rates may reach 300 µl./cm.2 hr. and more; systems with electrolytic solutions against solutions of glucose can produce twice this rate. These fluxes are of the same order of magnitude as the liquid transport rates across such living structures as the mucosa of dog gall bladder, ileum, and urinary bladder. PMID:13708691

Oral rehydration therapy for preoperative fluid and electrolyte management.

PubMed

Taniguchi, Hideki; Sasaki, Toshio; Fujita, Hisae

2011-01-01

Preoperative fluid and electrolyte management is usually performed by intravenous therapy. We investigated the safety and effectiveness of oral rehydration therapy (ORT) for preoperative fluid and electrolyte management of surgical patients. The study consisted of two studies, designed as a prospective observational study. In a pilot study, 20 surgical patients consumed 1000 mL of an oral rehydration solution (ORS) until 2 h before induction of general anesthesia. Parameters such as serum electrolyte concentrations, fractional excretion of sodium (FENa) as an index of renal blood flow, volume of esophageal-pharyngeal fluid and gastric fluid (EPGF), and patient satisfaction with ORT were assessed. In a follow-up study to assess the safety of ORT, 1078 surgical patients, who consumed ORS until 2 h before induction of general anesthesia, were assessed. In the pilot study, water, electrolytes, and carbohydrate were effectively and safely supplied by ORT. The FENa value was increased at 2 h following ORT. The volume of EPGF collected following the induction of anesthesia was 5.3±5.6 mL. In the follow-up study, a small amount of vomiting occurred in one patient, and no aspiration occurred in the patients. These results suggest that ORT is a safe and effective therapy for the preoperative fluid and electrolyte management of selected surgical patients.

Effect of milk protein addition to a carbohydrate-electrolyte rehydration solution ingested after exercise in the heat.

PubMed

James, Lewis J; Clayton, David; Evans, Gethin H

2011-02-01

The present study examined the effects of milk protein on rehydration after exercise in the heat, via the comparison of energy- and electrolyte content-matched carbohydrate and carbohydrate-milk protein solutions. Eight male subjects lost 1·9 (SD 0·2) % of their body mass by intermittent exercise in the heat and rehydrated with 150% of their body mass loss with either a 65 g/l carbohydrate solution (trial C) or a 40 g/l carbohydrate, 25 g/l milk protein solution (trial CP). Urine samples were collected before and after exercise and for 4 h after rehydration. Total cumulative urine output after rehydration was greater for trial C (1212 (SD 310) ml) than for trial CP (931 (SD 254) ml) (P < 0·05), and total fluid retention over the study was greater after ingestion of drink CP (55 (SD 12) %) than that after ingestion of drink C (43 (SD 15) %) (P < 0·05). At the end of the study period, whole body net fluid balance (P < 0·05) was less negative for trial CP (-0·26 (SD 0·27) litres) than for trial C (-0·52 (SD 0·30) litres), and although net negative for both the trials, it was only significantly negative after ingestion of drink C (P < 0·05). The results of the present study suggest that when matched for energy density and fat content, as well as for Na and K concentration, and when ingested after exercise-induced dehydration, a carbohydrate-milk protein solution is better retained than a carbohydrate solution. These results suggest that gram-for-gram, milk protein is more effective at augmenting fluid retention than carbohydrate.

Towards Versatile and Sustainable Hydrogen Production through Electrocatalytic Water Splitting: Electrolyte Engineering

PubMed Central

Shinagawa, Tatsuya

2017-01-01

Abstract Recent advances in power generation from renewable resources necessitate conversion of electricity to chemicals and fuels in an efficient manner. Electrocatalytic water splitting is one of the most powerful and widespread technologies. The development of highly efficient, inexpensive, flexible, and versatile water electrolysis devices is desired. This review discusses the significance and impact of the electrolyte on electrocatalytic performance. Depending on the circumstances under which the water splitting reaction is conducted, the required solution conditions, such as the identity and molarity of ions, may significantly differ. Quantitative understanding of such electrolyte properties on electrolysis performance is effective to facilitate the development of efficient electrocatalytic systems. The electrolyte can directly participate in reaction schemes (kinetics), affect electrode stability, and/or indirectly impact the performance by influencing the concentration overpotential (mass transport). This review aims to guide fine‐tuning of the electrolyte properties, or electrolyte engineering, for (photo)electrochemical water splitting reactions. PMID:27984671

Towards Versatile and Sustainable Hydrogen Production through Electrocatalytic Water Splitting: Electrolyte Engineering.

PubMed

Shinagawa, Tatsuya; Takanabe, Kazuhiro

2017-04-10

Recent advances in power generation from renewable resources necessitate conversion of electricity to chemicals and fuels in an efficient manner. Electrocatalytic water splitting is one of the most powerful and widespread technologies. The development of highly efficient, inexpensive, flexible, and versatile water electrolysis devices is desired. This review discusses the significance and impact of the electrolyte on electrocatalytic performance. Depending on the circumstances under which the water splitting reaction is conducted, the required solution conditions, such as the identity and molarity of ions, may significantly differ. Quantitative understanding of such electrolyte properties on electrolysis performance is effective to facilitate the development of efficient electrocatalytic systems. The electrolyte can directly participate in reaction schemes (kinetics), affect electrode stability, and/or indirectly impact the performance by influencing the concentration overpotential (mass transport). This review aims to guide fine-tuning of the electrolyte properties, or electrolyte engineering, for (photo)electrochemical water splitting reactions. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Concentrated Electrolyte for the Sodium-Oxygen Battery: Solvation Structure and Improved Cycle Life.

PubMed

He, Mingfu; Lau, Kah Chun; Ren, Xiaodi; Xiao, Neng; McCulloch, William D; Curtiss, Larry A; Wu, Yiying

2016-12-05

Alkali metal-oxygen batteries are of great interests for energy storage because of their unparalleled theoretical energy densities. Particularly attractive is the emerging Na-O 2 battery because of the formation of superoxide as the discharge product. Dimethyl sulfoxide (DMSO) is a promising solvent for this battery but its instability towards Na makes it impractical in the Na-O 2 battery. Herein we report the enhanced stability of Na in DMSO solutions containing concentrated sodium trifluoromethanesulfonimide (NaTFSI) salts (>3 mol kg -1 ). Raman spectra of NaTFSI/DMSO electrolytes and ab initio molecular dynamics simulation reveal the Na + solvation number in DMSO and the formation of Na(DMSO) 3 (TFSI)-like solvation structure. The majority of DMSO molecules solvating Na + in concentrated solutions reduces the available free DMSO molecules that can react with Na and renders the TFSI anion decomposition, which protects Na from reacting with the electrolyte. Using these concentrated electrolytes, Na-O 2 batteries can be cycled forming sodium superoxide (NaO 2 ) as the sole discharge product with improved long cycle life, highlighting the beneficial role of concentrated electrolytes for Na-based batteries. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Concentrated Electrolyte for the Sodium-Oxygen Battery: Solvation Structure and Improved Cycle Life

DOE PAGES

He, Mingfu; Lau, Kah Chun; Ren, Xiaodi; ...

2016-11-03

Alkali metal-oxygen batteries are of great interests for energy storage because of their unparalleled theoretical energy densities. Particularly attractive is the emerging Na-O 2 battery because of the formation of superoxide as the discharge product. Dimethyl sulfoxide (DMSO) is a promising solvent for this battery but its instability towards Na makes it impractical in the Na-O 2 battery. Here in this paper, we report the enhanced stability of Na in DMSO solutions containing concentrated sodium trifluoromethanesulfonimide (NaTFSI) salts (>3molkg -1). Raman spectra of NaTFSI/DMSO electrolytes and abinitio molecular dynamics simulation reveal the Na + solvation number in DMSO and themore » formation of Na(DMSO) 3(TFSI)-like solvation structure. The majority of DMSO molecules solvating Na + in concentrated solutions reduces the available free DMSO molecules that can react with Na and renders the TFSI anion decomposition, which protects Na from reacting with the electrolyte. Using these concentrated electrolytes, Na-O 2 batteries can be cycled forming sodium superoxide (NaO 2) as the sole discharge product with improved long cycle life, highlighting the beneficial role of concentrated electrolytes for Na-based batteries.« less

Preoperative fluid and electrolyte management with oral rehydration therapy.

PubMed

Taniguchi, Hideki; Sasaki, Toshio; Fujita, Hisae; Takamori, Mina; Kawasaki, Rieko; Momiyama, Yukinori; Takano, Osami; Shibata, Toshinari; Goto, Takahisa

2009-01-01

We hypothesized that oral rehydration therapy using an oral rehydration solution may be effective for preoperative fluid and electrolyte management in surgical patients before the induction of general anesthesia, and we investigated the safety and effectiveness of oral rehydration therapy as compared with intravenous therapy. Fifty female patients who underwent breast surgery were randomly allocated to two groups. Before entry to the operation room and the induction of general anesthesia, 25 patients drank 1000 ml of an oral rehydration solution ("oral group") and 25 patients were infused with 1000 ml of an intravenous electrolyte solution ("intravenous group"). Parameters such as electrolyte concentrations in serum and urine, urine volume, vital signs, vomiting and aspiration, volumes of esophageal-pharyngeal fluid and gastric fluid (EPGF), and patient satisfaction with the therapy (as surveyed by a questionnaire) were assessed. After treatment, the serum sodium concentration and the hematocrit value, which both declined within the normal limits, were significantly higher in the oral group than in the intravenous group (sodium, 140.8 +/- 2.9 mEq x l(-1) in the oral group and 138.7 +/- 1.9 mEq x l(-1) in the intravenous group; P = 0.005; hematocrit, 39.03 +/- 4.16% in the oral group and 36.15 +/- 3.41% in the intravenous group; P = 0.01). No significant difference was observed in serum glucose values. Urine volume was significantly larger in the oral group (864.9 +/- 211.5 ml) than in the intravenous group (561.5 +/- 216.0 ml; P < 0.001). The fractional excretion of sodium (FENa), as an index of renal blood flow, was increased in both groups following treatment (0.8 +/- 0.5 in the oral group and 0.8 +/- 0.3 in the intravenous group). Patient satisfaction with the therapy favored the oral rehydration therapy, as judged by factors such as "feeling of hunger", "occurrence of dry mouth", and "less restriction in physical activity". The volume of EPGF collected

Non-existence of time-periodic solutions of the Dirac equation in a Reissner-Nordström black hole background

NASA Astrophysics Data System (ADS)

Finster, Felix; Smoller, Joel; Yau, Shing-Tung

2000-04-01

It is shown analytically that the Dirac equation has no normalizable, time-periodic solutions in a Reissner-Nordström black hole background; in particular, there are no static solutions of the Dirac equation in such a background metric. The physical interpretation is that Dirac particles can either disappear into the black hole or escape to infinity, but they cannot stay on a periodic orbit around the black hole.

Surface and capillary forces encountered by zinc sulfide microspheres in aqueous electrolyte.

PubMed

Gillies, Graeme; Kappl, Michael; Butt, Hans-Jürgen

2005-06-21

The colloid probe technique was used to investigate the interactions between individual zinc sulfide (ZnS) microspheres and an air bubble in electrolyte solution. Incorporation of zinc ions into the electrolyte solution overcomes the disproportionate zinc ion dissolution and mimics high-volume-fraction conditions common in flotation. Determined interaction forces revealed a distinct lack of long-ranged hydrophobic forces, indicated by the presence of a DLVO repulsion prior to particle engulfment. Single microsphere contact angles were determined from particle-bubble interactions. Contact angles increased with decreasing radii and with surface oxidation. Surface modification by the absorption of copper and subsequently potassium O-ethyldithiocarbonate (KED) reduced repulsive forces and strongly increased contact angles.

Electrolyte-gated transistors based on conducting polymer nanowire junction arrays.

PubMed

Alam, Maksudul M; Wang, Jun; Guo, Yaoyao; Lee, Stephanie P; Tseng, Hsian-Rong

2005-07-07

In this study, we describe the electrolyte gating and doping effects of transistors based on conducting polymer nanowire electrode junction arrays in buffered aqueous media. Conducting polymer nanowires including polyaniline, polypyrrole, and poly(ethylenedioxythiophene) were investigated. In the presence of a positive gate bias, the device exhibits a large on/off current ratio of 978 for polyaniline nanowire-based transistors; these values vary according to the acidity of the gate medium. We attribute these efficient electrolyte gating and doping effects to the electrochemically fabricated nanostructures of conducting polymer nanowires. This study demonstrates that two-terminal devices can be easily converted into three-terminal transistors by simply immersing the device into an electrolyte solution along with a gate electrode. Here, the field-induced modulation can be applied for signal amplification to enhance the device performance.

INORGANIC ELECTROLYTES IN ANHYDROUS ACETONITRILE. Technical Report No. 5

DOE Office of Scientific and Technical Information (OSTI.GOV)

Janz, G.J.; Marcinkowsky, A.E.

Research concerned with the properties of inorganic electrolytes in anhydrous acetonitrile is reported. Infor mation related to ionic interactions, solute-solvent interactions and solute-solute interactions is emphasized. The work is differentiated into phases including that pertaining to the region of dilute concentration in which Kl was studied, the region of high concentration in which. AgNO/sub 3/ was studied, and systems which exhibit pronounced complexion behavior for which the cobaltous halide salts were investigated. Discussions of procedures, and result interpretation are included with data. (J.R.D.)

Galvanic Tongue Stimulation Inhibits Five Basic Tastes Induced by Aqueous Electrolyte Solutions.

PubMed

Aoyama, Kazuma; Sakurai, Kenta; Sakurai, Satoru; Mizukami, Makoto; Maeda, Taro; Ando, Hideyuki

2017-01-01

Galvanic tongue stimulation (GTS) modulates taste sensation. However, the effect of GTS is contingent on the electrode polarity in the proximity of the tongue. If an anodal electrode is attached in the proximity of the tongue, an electrical or metallic taste is elicited. On the other hand, if only cathodal electrode is attached in the proximity of the tongue, the salty taste, which is induced by electrolyte materials, is inhibited. The mechanism of this taste inhibition is not adequately understood. In this study, we aim to demonstrate that the inhibition is cause by ions, which elicit taste and which migrate from the taste sensors on the tongue by GTS. We verified the inhibitory effect of GTS on all five basic tastes induced by electrolyte materials. This technology is effective for virtual reality systems and interfaces to support dietary restrictions. Our findings demonstrate that cathodal-GTS inhibits all the five basic tastes. The results also support our hypothesis that the effects of cathodal-GTS are caused by migrating tasting ions in the mouth.

Solid lithium ion conducting electrolytes and methods of preparation

DOEpatents

Narula, Chaitanya K; Daniel, Claus

2013-05-28

A composition comprised of nanoparticles of lithium ion conducting solid oxide material, wherein the solid oxide material is comprised of lithium ions, and at least one type of metal ion selected from pentavalent metal ions and trivalent lanthanide metal ions. Solution methods useful for synthesizing these solid oxide materials, as well as precursor solutions and components thereof, are also described. The solid oxide materials are incorporated as electrolytes into lithium ion batteries.

Solid lithium ion conducting electrolytes and methods of preparation

DOEpatents

Narula, Chaitanya K.; Daniel, Claus

2015-11-19

A composition comprised of nanoparticles of lithium ion conducting solid oxide material, wherein the solid oxide material is comprised of lithium ions, and at least one type of metal ion selected from pentavalent metal ions and trivalent lanthanide metal ions. Solution methods useful for synthesizing these solid oxide materials, as well as precursor solutions and components thereof, are also described. The solid oxide materials are incorporated as electrolytes into lithium ion batteries.

Enhancement in Diffusion of Electrolyte through Membrane Using Ultrasonic Dialysis Equipment with Plane Membrane

NASA Astrophysics Data System (ADS)

Li, Hui; Ohdaira, Etsuzo; Ide, Masao

1995-05-01

Application of ultrasound to accelerate the dialysis separation of electrolytes through a membrane was studied with ultrasonic dialysis equipment. The experiments were conducted with cellophane membrane and KCl solution, CH3COONa solution, and a mixture of KCl and saponin solutions. It was found that the diffusion velocity of electrolyte through a membrane with ultrasonic irradiation is faster than that without ultrasonic irradiation, and it increases with acoustic pressure. It has become clear that the reasons for enhancement caused by ultrasound are increase in liquid particle velocity and diffusion coefficient due to ultrasonic vibration. It was confirmed that the permeability of the membrane was not degraded by ultrasound in the ranges of acoustic pressure and irradiation time in this study.

Facile and scalable fabrication of polymer-ceramic composite electrolyte with high ceramic loadings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pandian, Amaresh Samuthira; Chen, Xi Chelsea; Chen, Jihua

Solid state electrolytes are a promising alternative to flammable liquid electrolytes for high-energy lithium battery applications. In this work polymer-ceramic composite electrolyte membrane with high ceramic loading (greater than 60 vol%) is fabricated using a model polymer electrolyte poly(ethylene oxide) + lithium trifluoromethane sulfonate and a lithium-conducting ceramic powder. The effects of processing methods, choice of plasticizer and varying composition on ionic conductivity of the composite electrolyte are thoroughly investigated. The physical, structural and thermal properties of the composites are exhaustively characterized. We demonstrate that aqueous spray coating followed by hot pressing is a scalable and inexpensive technique to obtainmore » composite membranes that are amazingly dense and uniform. The ionic conductivity of composites fabricated using this protocol is at least one order of magnitude higher than those made by dry milling and solution casting. The introduction of tetraethylene glycol dimethyl ether further increases the ionic conductivity. The composite electrolyte's interfacial compatibility with metallic lithium and good cyclability is verified by constructing lithium symmetrical cells. As a result, a remarkable Li + transference number of 0.79 is discovered for the composite electrolyte.« less

Facile and scalable fabrication of polymer-ceramic composite electrolyte with high ceramic loadings

DOE PAGES

Pandian, Amaresh Samuthira; Chen, Xi Chelsea; Chen, Jihua; ...

2018-04-24

Solid state electrolytes are a promising alternative to flammable liquid electrolytes for high-energy lithium battery applications. In this work polymer-ceramic composite electrolyte membrane with high ceramic loading (greater than 60 vol%) is fabricated using a model polymer electrolyte poly(ethylene oxide) + lithium trifluoromethane sulfonate and a lithium-conducting ceramic powder. The effects of processing methods, choice of plasticizer and varying composition on ionic conductivity of the composite electrolyte are thoroughly investigated. The physical, structural and thermal properties of the composites are exhaustively characterized. We demonstrate that aqueous spray coating followed by hot pressing is a scalable and inexpensive technique to obtainmore » composite membranes that are amazingly dense and uniform. The ionic conductivity of composites fabricated using this protocol is at least one order of magnitude higher than those made by dry milling and solution casting. The introduction of tetraethylene glycol dimethyl ether further increases the ionic conductivity. The composite electrolyte's interfacial compatibility with metallic lithium and good cyclability is verified by constructing lithium symmetrical cells. As a result, a remarkable Li + transference number of 0.79 is discovered for the composite electrolyte.« less

Apatite grown in niobium by two-step plasma electrolytic oxidation.

PubMed

Pereira, Bruno Leandro; Lepienski, Carlos Maurício; Mazzaro, Irineu; Kuromoto, Neide Kazue

2017-08-01

Plasma electrolytic oxidation (PEO) of niobium plates were done electrochemically in two steps with electrolytes containing phosphorous and calcium being observed the formation of crystalline apatite. All samples were submitted to a first step of PEO using an electrolyte containing phosphate ions. The second oxidization step was made using three different electrolytes. Some samples were oxidized by PEO in electrolyte containing calcium, while in other samples it was used two mixtures of phosphoric acid and calcium acetate monohydrate solutions. Three different surface layers were obtained. The morphology and chemical composition of the films were analyzed by scanning electronic microscopy (SEM), and energy dispersive spectroscopy (EDS) respectively. It was observed that all samples submitted to two-step oxidation shown porous surface and a calcium and phosphorus rich layer. Average surface roughness (Ra) was measured by a profilometer remaining in the sub-micrometric range. The contact angle by sessile drop technique, using 1μL of distilled water was performed with an optical goniometer. It was verified a higher hydrophilicity in all surfaces compared to the polished niobium. Orthorhombic Nb 2 O 5 was identified by XRD in the oxide layer. Crystalline apatite was identified by XRD in surfaces after the second oxidation made with the Ca-rich electrolyte and a mixture of an electrolyte richer in Ca compared to P. These results indicate that a two-step oxidized niobium surface present great features for applications in the osseointegration processes: favorable chemical composition that increase the biocompatibility, the formation of crystalline niobium pentoxide (orthorhombic), high hydrophilicity and formation of crystalline calcium phosphate (apatite) under adequate electrolyte composition. Copyright © 2016 Elsevier B.V. All rights reserved.

High-compactness coating grown by plasma electrolytic oxidation on AZ31 magnesium alloy in the solution of silicate-borax

NASA Astrophysics Data System (ADS)

Shen, M. J.; Wang, X. J.; Zhang, M. F.

2012-10-01

A ceramic coating was formed on the surface of AZ31 magnesium alloy by plasma electrolytic oxidation (PEO) in the silicate solution with and without borax doped. The composition, morphology, elements and roughness as well as mechanical property of the coating were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectrometry (EDS), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and reciprocal-sliding tribometer. The results show that the PEO coating is mainly composed of magnesia. When using borax dope, boron element is permeating into the coating and the boron containing phase exist in the form of amorphous. In addition, the microhardness and compactness of the PEO coating are improved significantly due to doped borax.

Investigations of oxygen reduction reactions in non-aqueous electrolytes and the lithium-air battery

NASA Astrophysics Data System (ADS)

O'Laoire, Cormac Micheal

Unlocking the true energy capabilities of the lithium metal negative electrode in a lithium battery has until now been limited by the low capacity intercalation and conversion reactions at the positive electrodes. This is overcome by removing these electrodes and allowing lithium to react directly with oxygen in the atmosphere forming the Li-air battery. Chapter 2 discusses the intimate role of electrolyte, in particular the role of ion conducting salts on the mechanism and kinetics of oxygen reduction in non-aqueous electrolytes designed for such applications and in determining the reversibility of the electrode reactions. Such fundamental understanding of this high energy density battery is crucial to harnessing its full energy potential. The kinetics and mechanisms of O2 reduction in solutions of hexafluorophosphate salts of the general formula X+ PF6-, where, X = tetra butyl ammonium (TBA), K, Na and Li, in acetonitrile have been studied on glassy carbon electrodes using cyclic voltammetry (CV) and rotating disk electrode (RDE) techniques. Our results show that cation choice strongly influences the reduction mechanism of O2. Electrochemical data supports the view that alkali metal oxides formed via electrochemical and chemical reactions passivate the electrode surface inhibiting the kinetics and reversibility of the processes. The O2 reduction mechanisms in the presence of the different cations have been supplemented by kinetic parameters determined from detailed analyses of the CV and RDE data. The organic solvent present in the Li+-conducting electrolyte has a major role on the reversibility of each of the O2 reduction products as found from the work discussed in the next chapter. A fundamental study of the influence of solvents on the oxygen reduction reaction (ORR) in a variety of non-aqueous electrolytes was conducted in chapter 4. In this work special attention was paid to elucidate the mechanism of the oxygen electrode processes in the rechargeable Li

Synthesis, characterization and application of doped electrolytic manganese dioxides

NASA Astrophysics Data System (ADS)

Jantscher, Wolfgang; Binder, Leo; Fiedler, Dirk A.; Andreaus, Reinhard; Kordesch, Karl

Electrolytic manganese dioxides (EMDs) were prepared on the 100 g scale by anodic deposition from acidic aqueous solutions of manganese sulfate. In situ doping with titanium ions was achieved by addition of tetra- n-butoxytitanium to the electrolytic bath. Samples were also doped ex situ by washing the products with aqueous barium hydroxide solution. The EMDs were characterized by electron microscopy studies and BET surface area determinations. Cyclic abrasive stripping voltammetry was successfully applied to evaluate the rechargeability of the newly synthesized undoped and doped EMDs in 9 M KOH. Relative discharge capacities at different depths of discharge (DOD) with respect to the first one-electron reduction of γ-MnO 2 are compared for different EMDs. At about 30% DOD, resulting relative discharge capacities show essentially the same trend as those measured in AA cells from about 10 to 20 discharge/charge cycles onwards. Accordingly, titanium-doped EMD was shown to exhibit superior charge retention and rechargeability when compared to the titanium-free samples.

Oral Rehydration Therapy for Preoperative Fluid and Electrolyte Management

PubMed Central

Taniguchi, Hideki; Sasaki, Toshio; Fujita, Hisae

2011-01-01

Aim: Preoperative fluid and electrolyte management is usually performed by intravenous therapy. We investigated the safety and effectiveness of oral rehydration therapy (ORT) for preoperative fluid and electrolyte management of surgical patients. Methods: The study consisted of two studies, designed as a prospective observational study. In a pilot study, 20 surgical patients consumed 1000 mL of an oral rehydration solution (ORS) until 2 h before induction of general anesthesia. Parameters such as serum electrolyte concentrations, fractional excretion of sodium (FENa) as an index of renal blood flow, volume of esophageal-pharyngeal fluid and gastric fluid (EPGF), and patient satisfaction with ORT were assessed. In a follow-up study to assess the safety of ORT, 1078 surgical patients, who consumed ORS until 2 h before induction of general anesthesia, were assessed. Results: In the pilot study, water, electrolytes, and carbohydrate were effectively and safely supplied by ORT. The FENa value was increased at 2 h following ORT. The volume of EPGF collected following the induction of anesthesia was 5.3±5.6 mL. In the follow-up study, a small amount of vomiting occurred in one patient, and no aspiration occurred in the patients. Conclusion: These results suggest that ORT is a safe and effective therapy for the preoperative fluid and electrolyte management of selected surgical patients. PMID:21897763

Role of succinonitrile in improving ionic conductivity of sodium-ion conductive polymer electrolyte

NASA Astrophysics Data System (ADS)

Nair, Manjula G.; Mohapatra, Saumya R.

2018-05-01

Sodium ion conducting solid polymer electrolytes were prepared using poly (ethylene oxide) (PEO) as polymer matrix, sodium perchlorate (NaClO4) as salt and succinonitrile (SN) as a plasticizer by solution casting technique. By blending a plastic crystal such as succinonitrile (SN) with PEO-NaClO4 electrolyte system, we aimed at improving the ionic conductivity by weakening the ether oxygen-Na+ interactions. The XRD and FTIR studies revealed structural and micro-structural changes in the blended electrolytes which aids in improving ionic conductivity. Also, DSC measurements showed improved segmental motion in the blended polymer electrolytes due to plasticizing effect of SN. The maximum ionic conductivity observed at room temperature is 1.13×10-5 S cm-1 merely for 7 wt. % of SN, which is one order higher than pure polymer-salt complex. The thermo-gravimetric analysis (TGA) suggests that blending of SN with polymer electrolyte had no detrimental effect on its thermal stability.

Fuel cell having electrolyte

DOEpatents

Wright, Maynard K.

1989-01-01

A fuel cell having an electrolyte control volume includes a pair of porous opposed electrodes. A maxtrix is positioned between the pair of electrodes for containing an electrolyte. A first layer of backing paper is positioned adjacent to one of the electrodes. A portion of the paper is substantially previous to the acceptance of the electrolyte so as to absorb electrolyte when there is an excess in the matrix and to desorb electrolyte when there is a shortage in the matrix. A second layer of backing paper is positioned adjacent to the first layer of paper and is substantially impervious to the acceptance of electrolyte.

A study on lithium/air secondary batteries-Stability of the NASICON-type lithium ion conducting solid electrolyte in alkaline aqueous solutions

NASA Astrophysics Data System (ADS)

Shimonishi, Yuta; Zhang, Tao; Imanishi, Nobuyuki; Im, Dongmin; Lee, Dong Joon; Hirano, Atsushi; Takeda, Yasuo; Yamamoto, Osamu; Sammes, Nigel

The stability of the high lithium ion conducting glass ceramics, Li 1+ x+ yTi 2- xAl xSi yP 3- yO 12 (LTAP) in alkaline aqueous solutions with and without LiCl has been examined. A significant conductivity decrease of the LTAP plate immersed in 0.057 M LiOH aqueous solution at 50 °C for 3 weeks was observed. However, no conductivity change of the LTAP plate immersed in LiCl saturated LiOH aqueous solutions at 50 °C for 3 weeks was observed. The pH value of the LiCl-LiOH-H 2O solution with saturated LiCl was in a range of 7-9. The molarity of LiOH and LiCl in the LiOH and LiCl saturated aqueous solution were estimated to be 5.12 and 11.57 M, respectively, by analysis of Li + and OH -. The high concentration of LiOH and the low pH value of 8.14 in this solution suggested that the dissociation of LiOH into Li + and OH - is too low in the solution with a high concentration of Li +. These results suggest that the water stable LTAP could be used as a protect layer of the lithium metal anode in the lithium/air cell with LiCl saturated aqueous solution as the electrolyte, because the content of OH - ions in the LiCl saturated aqueous solution does not increase via the cell reaction of Li + 1/2O 2 + H 2O → 2LiOH, and LTAP is stable under a deep discharge state.

Influence of ion sterics on diffusiophoresis and electrophoresis in concentrated electrolytes

NASA Astrophysics Data System (ADS)

Stout, Robert F.; Khair, Aditya S.

2017-01-01

We quantify the diffusiophoresis and electrophoresis of a uniformly charged, spherical colloid in a binary electrolyte using modified Poisson-Nernst-Planck equations that account for steric repulsion between finite sized ions. Specifically, we utilize the Bikerman (Bik) lattice gas model and the Carnahan-Starling (CS) and Boublik-Mansoori-Carnahan-Starling-Leland (BMCSL) equations of state for monodisperse and polydisperse, respectively, hard spheres. We compute the phoretic mobility for weak applied fields using an asymptotic approach for thin diffuse layers, where ion steric effects are expected to be most prevalent. The thin diffuse layer limit requires λD/R →0 , where λD is the Debye screening length and R is the particle radius; this limit is readily attained for micron-sized colloids in concentrated electrolytic solutions. It is well known that the classic Poisson-Boltzmann (PB) model for pointlike, noninteracting ions leads to a prediction of a maximum in both the diffusiophoretic and electrophoretic mobilities with increasing particle zeta potential (at fixed λD/R ). In contrast, we find that ion sterics essentially eliminate this maximum (for reasonably attainable zeta potentials) and increase the mobility relative to PB. Next, we consider the more experimentally relevant case of a particle with a constant surface charge density and vary the electrolyte concentration, neglecting charge regulation on surface active sites. Rather surprisingly, there is little difference between the predictions of the four models (PB, Bik, CS, and BMCSL) for electrophoretic mobility in concentrated solutions, at reasonable surface charge densities (˜1 -10 μ C /cm2 ). This is because as the concentration increases, the zeta potential is reduced (to below the thermal voltage for concentrations above about 1 M) and therefore the diffuse layer structure is largely unaffected by ion sterics. For gradients of symmetric electrolytes (equal diffusivities, charge, and size

Can oral rehydration solution be safely flavored at home?

PubMed

Nijssen-Jordan, C

1997-12-01

To determine the concentration of sodium, potassium, glucose, and osmolality of oral rehydration solutions (ORS) which have been flavored with varying amounts of unsweetened Kool-Aid powder, Jell-O powder, apple juice, or orange juice. Descriptive. Alberta Children's Hospital Chemistry Laboratory. None. Addition of varying amounts of flavoring easily available in all households to commercially available unsweetened ORS. Concentrations of electrolytes, glucose, and osmolality. Addition of fruit juices or flavor powders to commercially produced ORS does alter the electrolyte content and osmolality. When limited amounts of flavoring or juice is added, the osmolality of the solution approaches iso-osmolality. Small amounts of unsweetened Kool-Aid powder, Jell-O powder, and apple or orange juice can be added to oral rehydration solutions without significantly altering electrolyte composition and osmolality.

Formation of a Spinel Coating on AZ31 Magnesium Alloy by Plasma Electrolytic Oxidation

NASA Astrophysics Data System (ADS)

Sieber, Maximilian; Simchen, Frank; Scharf, Ingolf; Lampke, Thomas

2016-03-01

Plasma electrolytic oxidation (PEO) is a common means for the surface modification of light metals. However, PEO of magnesium substrates in dilute electrolytes generally leads to the formation of coatings consisting of unfavorable MgO magnesium oxide. By incorporation of electrolyte components, the phase constitution of the oxide coatings can be modified. Coatings consisting exclusively of MgAl2O4 magnesium-aluminum spinel are produced by PEO in an electrolyte containing hydroxide, aluminate, and phosphate anions. The hardness of the coatings is 3.5 GPa on Martens scale on average. Compared to the bare substrate, the coatings reduce the corrosion current density in dilute sodium chloride solution by approx. one order of magnitude and slightly shift the corrosion potential toward more noble values.

The thermodynamic parameters of the step dissociation of L-phenylalanyl in aqueous solution

NASA Astrophysics Data System (ADS)

Kochergina, L. A.; Emel'Yanov, A. V.; Krutova, O. N.; Gorboletova, G. G.

2007-10-01

The heats of interaction of L-phenylalanine with solutions of nitric acid and potassium and lithium hydroxides were determined calorimetrically at 288.15, 298.15, and 308.15 K and solution ionic strengths of 0.5, 0.75, and 1.0 in the presence of LiNO3 and KNO3. The standard thermodynamic characteristics (Δr H°, Δr G°, Δr S°, and Δ C {/p °} of acid-base interactions in aqueous solutions of L-phenylalanine were calculated. The influence of the concentration of background electrolytes and temperature on the heats of dissociation of L-phenylalanine was considered. A comparative analysis of the standard thermodynamic characteristics of step dissociation of L-phenylalanine and alanine was performed in terms of the modern concepts of the structure and physicochemical properties of these compounds and their solutions.

A physical organogel electrolyte: characterized by in situ thermo-irreversible gelation and single-ion-predominent conduction

PubMed Central

Kim, Young-Soo; Cho, Yoon-Gyo; Odkhuu, Dorj; Park, Noejung; Song, Hyun-Kon

2013-01-01

Electrolytes are characterized by their ionic conductivity (σi). It is desirable that overall σi results from the dominant contribution of the ions of interest (e.g. Li+ in lithium ion batteries or LIB). However, high values of cationic transference number (t+) achieved by solid or gel electrolytes have resulted in low σi leading to inferior cell performances. Here we present an organogel polymer electrolyte characterized by a high liquid-electrolyte-level σi (~101 mS cm−1) with high t+ of Li+ (>0.8) for LIB. A conventional liquid electrolyte in presence of a cyano resin was physically and irreversibly gelated at 60°C without any initiators and crosslinkers, showing the behavior of lower critical solution temperature. During gelation, σi of the electrolyte followed a typical Arrhenius-type temperature dependency, even if its viscosity increased dramatically with temperature. Based on the Li+-driven ion conduction, LIB using the organogel electrolyte delivered significantly enhanced cyclability and thermal stability. PMID:23715177

Cs{sup +} ion exchange kinetics in complex electrolyte solutions using hydrous crystalline silicotitanates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gu, D.; Nguyen, L.; Philip, C.V.

1997-12-01

TAM-5 is a hydrous crystalline sodium silicotitanate inorganic ion exchanger with a high selectivity for Cs{sup +}. The kinetics of Cs{sup +}-Na{sup +} ion exchange using TAM-5 in multicomponent electrolyte solutions were determined using batch experiments. For the powder, which is composed of crystals, a single-phase, homogeneous model fit the data best. For the granules, which were prepared from the powder, a two-phase, heterogeneous model resulted in an excellent fit of the data. Macropore and crystal diffusivities were determined by fitting the model to experimental data collected on the powder and the granules. Intracrystalline diffusivities were concentration dependent and weremore » on the order of 10{sup {minus}19} m{sup 2}/s. Macropore diffusivities were on the order of 10{sup {minus}10} m{sup 2}/s. Resistance to diffusion in the macropores was not significant for granules with diameters less than 15 {micro}m. A two-phase, homogeneous model, where liquid within the pores is in equilibrium with the solid, was also evaluated for the granules. Surprisingly, for the granules, an excellent fit of the data was obtained; however, the effective macropore diffusivity was 1.1 {times} 10{sup {minus}11} m{sup 2}/s, an order of magnitude smaller than the macropore diffusivity found using the two-phase, heterogeneous model.« less

Electrolyte formulations

DOEpatents

Zhu, Ye; Strand, Deidre; Cheng, Gang

2018-05-29

An electrochemical cell including a silicon-based anode and an electrolyte, where the electrolyte is formulated to contain solvents having cyclic sulfone or cyclic sulfite chemical structure. Specific additional solvent and salt combinations yield superior performance in these electrochemical cells.

Liquid electrolytes for lithium and lithium-ion batteries

NASA Astrophysics Data System (ADS)

Blomgren, George E.

A number of advances in electrolytes have occurred in the past 4 years, which have contributed to increased safety, wider temperature range of operation, better cycling and other enhancements to lithium-ion batteries. The changes to basic electrolyte solutions that have occurred to accomplish these advances are discussed in detail. The solvent components that have led to better low-temperature operation are also considered. Also, additives that have resulted in better structure of the solid electrolyte interphase (SEI) are presented as well as proposed methods of operation of these additives. Other additives that have lessened the flammability of the electrolyte when exposed to air and also caused lowering of the heat of reaction with the oxidized positive electrode are discussed. Finally, additives that act to open current-interrupter devices by releasing a gas under overcharge conditions and those that act to cycle between electrodes to alleviate overcharging are presented. As a class, these new electrolytes are often called "functional electrolytes". Possibilities for further progress in this most important area are presented. Another area of active work in the recent past has been the reemergence of ambient-temperature molten salt electrolytes applied to alkali metal and lithium-ion batteries. This revival of an older field is due to the discovery of new salt types that have a higher voltage window (particularly to positive potentials) and also have greatly increased hydrolytic stability compared to previous ionic liquids. While practical batteries have not yet emerged from these studies, the increase in the number of active researchers and publications in the area demonstrates the interest and potentialities of the field. Progress in the field is briefly reviewed. Finally, recent results on the mechanisms for capacity loss on shelf and cycling in lithium-ion cells are reviewed. Progress towards further market penetration by lithium-ion cells hinges on improved

Sieving of electrolytes at capillary wall of cat skeletal muscle by osmotic water flow.

PubMed

Watson, P D

1993-12-01

To test the hypothesis that a significant proportion of transcapillary water flow occurs through solute-restricting channels, we investigated the effects of transcapillary water movement on plasma electrolytes in isolated perfused cat skeletal muscle. The lower hindlimbs of anesthetized cats were perfused with a plasma-albumin solution and were weighed to determine transcapillary water movement. Osmolality was increased 60-70 mosmol/kgH2O with sucrose, creating water fluxes of 8-10 ml.min-1.100 g-1, and the changes in the venous concentrations of sodium, potassium, and chloride were determined. The ion concentrations were all reduced by 6-7% with no significant difference between them. The amount of reduction was quantitatively explained by the flow of ion-free water from the interstitial space into plasma and the diffusion of electrolyte in the same direction. These findings support the hypothesis that important water-only transcapillary channels exist in mammalian skeletal muscle. The observations may also explain some of the electrolyte changes seen in intense exercise.

Ionic liquids as electrolytes for non-aqueous solutions electrochemical supercapacitors in a temperature range of 20 °C-80 °C

NASA Astrophysics Data System (ADS)

Zhang, Lei; Tsay, Ken; Bock, Christina; Zhang, Jiujun

2016-08-01

To increase the operating temperature of the supercapacitors (SCs) without compromising their high cycle-life, several typical fluoro- and non-fluoro containing ionic liquids (EMI-mesylate, EMI-hydrogen sulfate, PP13-triflate, PP13-TFSI, and EMI-TFSI, as shown in Fig. 1) are studied as the electrolytes to prepare organic solutions for SC performance measurements using a two-electrode cell. Both cyclic voltammograms and charge/discharge curves at various temperatures such as 20, 40, 60 and 80 °C are collected. At 60 °C, the increased performance order in both rating and cyclability measurements are found to be as follows: 1) EMI-hydrogen sulfate < PP13-TFSI < EMI-mesylate < PP13-triflate < EMI-TFSI for rating; and 2) EMI-hydrogen sulfate < EMI-mesylate < PP13-Triflate < PP13-TFSI < EMI-TFSI for life-time. The fluoro-containing group of ILs, i.e., PP13-Triflate, PP13-TFSI and EMI-TFSI can give a specific capacitance between 100 and 170 F/g for various scan rates for a conventional carbon electrode, and an extended lifetime test of 10, 000 cycles with a capacitance degradation of less than 10%, indicating that these two ion liquids can be used for SC electrolytes operated at high temperature.

Sodium ion conducting polymer electrolyte membrane prepared by phase inversion technique

NASA Astrophysics Data System (ADS)

Harshlata, Mishra, Kuldeep; Rai, D. K.

2018-04-01

A mechanically stable porous polymer membrane of Poly(vinylidene fluoride-hexafluoropropylene) has been prepared by phase inversion technique using steam as a non-solvent. The membrane possesses semicrystalline network with enhanced amorphicity as observed by X-ray diffraction. The membrane has been soaked in an electrolyte solution of 0.5M NaPF6 in Ethylene Carbonate/Propylene Carbonate (1:1) to obtain the gel polymer electrolyte. The porosity and electrolyte uptake of the membrane have been found to be 67% and 220% respectively. The room temperature ionic conductivity of the membrane has been obtained as ˜ 0.3 mS cm-1. The conductivity follows Arrhenius behavior with temperature and gives activation energy as 0.8 eV. The membrane has been found to possess significantly large electrochemical stability window of 5.0 V.

Recent Developments of All-Solid-State Lithium Secondary Batteries with Sulfide Inorganic Electrolytes.

PubMed

Xu, Ruochen; Zhang, Shengzhao; Wang, Xiuli; Xia, Yan; Xia, Xinhui; Wu, Jianbo; Gu, Changdong; Tu, Jiangping

2018-04-20

Due to the increasing demand of security and energy density, all-solid-state lithium ion batteries have become the promising next-generation energy storage devices to replace the traditional liquid batteries with flammable organic electrolytes. In this Minireview, we focus on the recent developments of sulfide inorganic electrolytes for all-solid-state batteries. The challenges of assembling bulk-type all-solid-state batteries for industrialization are discussed, including low ionic conductivity of the present sulfide electrolytes, high interfacial resistance and poor compatibility between electrolytes and electrodes. Many efforts have been focused on the solutions for these issues. Although some progresses have been achieved, it is still far away from practical application. The perspectives for future research on all-solid-state lithium ion batteries are presented. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Urticaria due to polyethylene glycol-3350 and electrolytes for oral solution in a patient with jejunal nodular lymphoid hyperplasia.

PubMed

Zhang, Hongfeng; Henry, Winoah A; Chen, Lea Ann; Khashab, Mouen A

2015-01-01

Both jejunal nodular lymphoid hyperplasia (NLH) and polyethylene glycol (PEG)-3350 hypersensitivity are extremely rare. We describe a 30-year-old female who had previously taken a PEG-3350 bowel preparation without adverse effects, and presented for evaluation of chronic diarrhea. An upper and lower gastrointestinal endoscopy, and small bowel series were scheduled. PEG-3350 and electrolytes for oral solution was prescribed for bowel cleansing. During consumption of the bowel preparation she developed urticarial hypersensitivity. An alternative bowel preparation was used. Colonoscopy and upper endoscopy were normal, but small bowel series revealed innumerable sand-like lucencies in the jejunum. NLH was confirmed on biopsy from antegrade enteroscopy. This is the first case report on the pathological jejunal NLH in association with the PEG-3350 urticarial hypersensitivity. The potential pathophysiological etiology of this association is discussed.

Small volume isosmotic polyethylene glycol electrolyte balanced solution (PMF-100) in treatment of chronic nonorganic constipation.

PubMed

Corazziari, E; Badiali, D; Habib, F I; Reboa, G; Pitto, G; Mazzacca, G; Sabbatini, F; Galeazzi, R; Cilluffo, T; Vantini, I; Bardelli, E; Baldi, F

1996-08-01

The present multicenter double-blind placebo-controlled trial evaluates the therapeutic effectiveness of small-volume daily doses of an isosmotic polyethylene glycol (PEG) electrolyte solution in the treatment of chronic nonorganic constipation. After a complete diagnostic investigation, patients still constipated at the end of a four-week placebo-treatment run-in period were enrolled and randomized to receive either placebo or PEG solution 250 ml twice a day for the following eight weeks. Patients were assessed at four and eight weeks of treatment, and they reported frequency and modality of evacuation, use of laxatives, and relevant symptoms daily on a diary card. Oroanal and segmental large-bowel transit times were assessed with radiopaque markers during the fourth week of the run-in period and the last week of the treatment period. During the study period, dietary fiber and liquids were standardized and laxatives were allowed only after five consecutive days without a bowel movement. Of the 55 patients enrolled, five dropped out, three because of adverse events and two for reasons unrelated to therapy; another two were excluded from the efficacy analysis because of protocol violation. Of the remaining 48 patients (37 women, age 42 +/- 15 years, mean +/- SD), 23 were assigned to placebo and 25 to PEG treatment. In comparison to placebo, PEG solution induced a statistically significant increase in weekly bowel frequency at four weeks and at the end of the study (PEG: 4.8 +/- 2.3 vs placebo: 2.8 +/- 1.6; P < 0.002) and a significant decrease in straining at defecation (P < 0.01), stool consistency (P < 0.02), and use of laxatives (P < 0.03). Oroanal, left colon, and rectal transit times were significantly shortened by PEG treatment. There was no difference between controls and PEG-treated patients as far as abdominal symptoms and side effects were concerned. In conclusion, PEG solution at 250 ml twice a day is effective in increasing bowel frequency, accelerating

Impact resistant electrolytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Veith, Gabriel M.; Armstrong, Beth L.; Tenhaeff, Wyatt E.

A passively impact resistant composite electrolyte composition includes an electrolyte solvent, up to 2M of an electrolyte salt, and shear thickening ceramic particles having a polydispersity index of no greater than 0.1, an average particle size of in a range of 50 nm to 1 .mu.m, and an absolute zeta potential of greater than .+-.40 mV.

Development of PVA based micro-porous polymer electrolyte by a novel preferential polymer dissolution process

NASA Astrophysics Data System (ADS)

Subramania, A.; Kalyana Sundaram, N. T.; Sukumar, N.

A micro-porous polymer electrolyte based on PVA was obtained from PVA-PVC based polymer blend film by a novel preferential polymer dissolution technique. The ionic conductivity of micro-porous polymer electrolyte increases with increase in the removal of PVC content. Finally, the effect of variation of lithium salt concentration is studied for micro-porous polymer electrolyte of high ionic conductivity composition. The ionic conductivity of the micro-porous polymer electrolyte is measured in the temperature range of 301-351 K. It is observed that a 2 M LiClO 4 solution of micro-porous polymer electrolyte has high ionic conductivity of 1.5055 × 10 -3 S cm -1 at ambient temperature. Complexation and surface morphology of the micro-porous polymer electrolytes are studied by X-ray diffraction and SEM analysis. TG/DTA analysis informs that the micro-porous polymer electrolyte is thermally stable upto 277.9 °C. Chronoamperommetry and linear sweep voltammetry studies were made to find out lithium transference number and stability of micro-porous polymer electrolyte membrane, respectively. Cyclic voltammetry study was performed for carbon/micro-porous polymer electrolyte/LiMn 2O 4 cell to reveal the compatibility and electrochemical stability between electrode materials.

Elucidating the Higher Stability of Vanadium (V) Cations in Mixed Acid Based Redox Flow Battery Electrolytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vijayakumar, M.; Wang, Wei; Nie, Zimin

2013-11-01

The Vanadium (V) cation structures in mixed acid based electrolyte solution were analysed by density functional theory (DFT) based computational modelling and 51V and 35Cl Nuclear Magnetic Resonance (NMR) spectroscopy. The Vanadium (V) cation exists as di-nuclear [V2O3Cl2.6H2O]2+ compound at higher vanadium concentrations (≥1.75M). In particular, at high temperatures (>295K) this di-nuclear compound undergoes ligand exchange process with nearby solvent chlorine molecule and forms chlorine bonded [V2O3Cl2.6H2O]2+ compound. This chlorine bonded [V2O3Cl2.6H2O]2+ compound might be resistant to the de-protonation reaction which is the initial step in the precipitation reaction in Vanadium based electrolyte solutions. The combined theoretical and experimental approachmore » reveals that formation of chlorine bonded [V2O3Cl2.6H2O]2+ compound might be central to the observed higher thermal stability of mixed acid based Vanadium (V) electrolyte solutions.« less

Control Of Screening Of A Charged Particle In Electrolytic Aqueous Paul Trap

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Jae Hyun; Krstic, Predrag S.

2011-06-01

Individual charged particles could be trapped and confined by the combined radio-frequency and DC quadrupole electric field of an aqueous Paul trap. Viscosity of water improves confinement and extends the range of the trap parameters which characterize the stability of the trap. Electrolyte, if present in aqueous solution, may screen the charged particle and thus partially or fully suppress electrophoretic interaction with the applied filed, possibly reducing it to a generally much weaker dielectrophoretic interaction with an induced dipole. Applying molecular dynamics simulation we show that the quadrupole field has a different effect at the electrolyte ions and at muchmore » heavier charged particle, effectively eliminating the screening by electrolyte ions and reinstating the electrophoretic confinement.« less

Human Water and Electrolyte Balance

DTIC Science & Technology

2006-04-01

1996;53: S13–S16.) Mean Range Sport L/h Water polo 0.55 0.30–0.80 Cycling 0.80 0.29–1.25 Running 1.10 0.54–1.83 Basketball 1.11 0.70–1.60 Soccer 1.17...they interact to con- tribute in concert, rather than in isolation, to degrading exercise performance. The relative contribution of each factor may...decre- ment.55,64,65 Hyperhydration Hyperhydration is not easy to sustain, since overdrink- ing of water or carbohydrate - electrolyte solutions pro- duce

Relevant Features of a Triethylene Glycol Dimethyl Ether-Based Electrolyte for Application in Lithium Battery.

PubMed

Carbone, Lorenzo; Di Lecce, Daniele; Gobet, Mallory; Munoz, Stephen; Devany, Matthew; Greenbaum, Steve; Hassoun, Jusef

2017-05-24

Triethylene glycol dimethyl ether (TREGDME) dissolving lithium trifluoromethanesulfonate (LiCF 3 SO 3 ) is studied as a suitable electrolyte medium for lithium battery. Thermal and rheological characteristics, transport properties of the dissolved species, and the electrochemical behavior in lithium cell represent the most relevant investigated properties of the new electrolyte. The self-diffusion coefficients, the lithium transference numbers, the ionic conductivity, and the ion association degree of the solution are determined by pulse field gradient nuclear magnetic resonance and electrochemical impedance spectroscopy. The study sheds light on the determinant role of the lithium nitrate (LiNO 3 ) addition for allowing cell operation by improving the electrode/electrolyte interfaces and widening the voltage stability window. Accordingly, an electrochemical activation procedure of the Li/LiFePO 4 cell using the upgraded electrolyte leads to the formation of stable interfaces at the electrodes surface as clearly evidenced by cyclic voltammetry, impedance spectroscopy, and ex situ scanning electron microscopy. Therefore, the lithium battery employing the TREGDME-LiCF 3 SO 3 -LiNO 3 solution shows a stable galvanostatic cycling, a high efficiency, and a notable rate capability upon the electrochemical conditions adopted herein.

Lactulose vs polyethylene glycol 3350--electrolyte solution for treatment of overt hepatic encephalopathy: the HELP randomized clinical trial.

PubMed

Rahimi, Robert S; Singal, Amit G; Cuthbert, Jennifer A; Rockey, Don C

2014-11-01

Hepatic encephalopathy (HE) is a common cause of hospitalization in patients with cirrhosis. Pharmacologic treatment for acute (overt) HE has remained the same for decades. To compare polyethylene glycol 3350-electrolyte solution (PEG) and lactulose treatments in patients with cirrhosis admitted to the hospital for HE. We hypothesized that rapid catharsis of the gut using PEG may resolve HE more effectively than lactulose. The HELP (Hepatic Encephalopathy: Lactulose vs Polyethylene Glycol 3350-Electrolyte Solution) study is a randomized clinical trial in an academic tertiary hospital of 50 patients with cirrhosis (of 186 screened) admitted for HE. Participants were block randomized to receive treatment with PEG, 4-L dose (n = 25), or standard-of-care lactulose (n = 25) during hospitalization. The primary end point was an improvement of 1 or more in HE grade at 24 hours, determined using the hepatic encephalopathy scoring algorithm (HESA), ranging from 0 (normal clinical and neuropsychological assessments) to 4 (coma). Secondary outcomes included time to HE resolution and overall length of stay. A total of 25 patients were randomized to each treatment arm. Baseline clinical features at admission were similar in the groups. Thirteen of 25 patients in the standard therapy arm (52%) had an improvement of 1 or more in HESA score, thus meeting the primary outcome measure, compared with 21 of 23 evaluated patients receiving PEG (91%) (P < .01); 1 patient was discharged before final analysis and 1 refused participation. The mean (SD) HESA score at 24 hours for patients receiving standard therapy changed from 2.3 (0.9) to 1.6 (0.9) compared with a change from 2.3 (0.9) to 0.9 (1.0) for the PEG-treated groups (P = .002). The median time for HE resolution was 2 days for standard therapy and 1 day for PEG (P = .01). Adverse events were uncommon, and none was definitely study related. PEG led to more rapid HE resolution than standard therapy, suggesting that

Analytical calculation of electrolyte water content of a Proton Exchange Membrane Fuel Cell for on-board modelling applications

NASA Astrophysics Data System (ADS)

Ferrara, Alessandro; Polverino, Pierpaolo; Pianese, Cesare

2018-06-01

This paper proposes an analytical model of the water content of the electrolyte of a Proton Exchange Membrane Fuel Cell. The model is designed by accounting for several simplifying assumptions, which make the model suitable for on-board/online water management applications, while ensuring a good accuracy of the considered phenomena, with respect to advanced numerical solutions. The achieved analytical solution, expressing electrolyte water content, is compared with that obtained by means of a complex numerical approach, used to solve the same mathematical problem. The achieved results show that the mean error is below 5% for electrodes water content values ranging from 2 to 15 (given as boundary conditions), and it does not overcome 0.26% for electrodes water content above 5. These results prove the capability of the solution to correctly model electrolyte water content at any operating condition, aiming at embodiment into more complex frameworks (e.g., cell or stack models), related to fuel cell simulation, monitoring, control, diagnosis and prognosis.

Influence of electrolytes (TEABF4 and TEMABF4) on electrochemical performance of graphite oxide derived from needle coke.

PubMed

Yang, Sunhye; Kim, Ick-Jun; Choi, In-Sik; Bae, Mi-Kyeong; Kim, Hyun-Soo

2013-05-01

The structure of needle coke was changed to graphite oxide structure after oxidation treatment with 70 wt.% of nitric acid and sodium chlorate (NaClO3), and the inter-layer distance of the oxidized needle coke was expanded to 6.9 angstroms. The first charge profile of the oxidized needle coke-cell with 1.2 M TEMABF4/acetonitrile solution displayed that the intercalation of electrolyte ions into the inter-layer occurred at 1.0 V, which value is lower than 1.3 V of the oxidized needle coke-cell with 1.2 M TEABF4/acetonitrile solution. After first charge/discharge, the cell using TEMABF4 electrolyte exhibited smaller electrode resistance of 0.05 omega, and larger specific volume capacitance of 25.5 F/ml at the two-electrode system in the potential range 0-2.5 V than those of the cell using TEABF4 electrolyte. Compared to the TEABF4 electrolyte, better electrochemical performance of the TEMABF4 electrolyte in the oxidized needle coke may be caused by the smaller cation (TEMA+) size and better ion mobility in the nanopores between inter-layers.

Probe diffusion of labeled polymers inside polyacrylic acid solutions: A polyelectrolyte effect

NASA Astrophysics Data System (ADS)

Mishra, Banani; Mithra, K.; Khandai, Santripti; Jena, Sidhartha S.

2018-05-01

Probe diffusion of fluorescently labeled Dextran 40 inside polyelectrolyte solution of polyacrylic acid (PAA) was investigated using Fluorescence Recovery After Photobleaching technique. The crowding and interaction effects on probe diffusion were controlled by tuning background polymer and added external electrolyte concentration. For all the salt concentration, an overall decrease in diffusion coefficient is observed with rise in polymer concentration. The diffusion coefficient decreases with decrease in salt concentration whereas the solution viscosity increases, indicating a competition between viscous drag and electrostatic interaction. A large positive deviation from the ideal Stokes-Einstein relation is observed for high polymer and low salt concentration, which reduces markedly with addition of salt confirming polyelectrolyte effects, plays a major role in deciding the probe diffusion.

The Role of Electrolyte Upon the SEI Formation Characteristics and Low Temperature Performance of Lithium-Ion Cells With Graphite Anodes

NASA Technical Reports Server (NTRS)

Smart, M. C.; Ratnakumar, B. V.; Greenbaum, S.; Surampudi, S.

2000-01-01

Quarternary lithium-ion battery electrolyte solutions containing ester co-solvents in mixtures of carbonates have been demonstrated to have high conductivity at low temperatures (< -20C). However, in some cases the presence of such co-solvents does not directly translate into improved low temperature cell performance, presumably due to the formation of ionically resistive surface films on carbonaceous anodes. In order to understand this behavior, a number of lithium-graphite cells have been studied containing electrolytes with various ester co-solvents, including methyl acetate (MA), ethyl acetate (EA), ethyl propionate (EP), and ethyl butyrate (EB). The charge/discharge characterization of these cells indicates that the higher molecular weight esters result in electrolytes which possess superior low temperature performance in contrast to the lower molecular weight ester-containing solutions, even though these solutions display lower conductivity values.

Raising the Corrosion Resistance of Low-Carbon Steels by Electrolytic-Plasma Saturation with Nitrogen and Carbon

NASA Astrophysics Data System (ADS)

Kusmanov, S. A.; Grishina, E. P.; Belkin, P. N.; Kusmanova, Yu. V.; Kudryakova, N. O.

2017-05-01

Structural features of the external oxide layer and internal nitrided, carbonitrided and carburized layers in steels 10, 20 and St3 produced by the method of electrolytic plasma treatment are studied. Specimens of the steels are tested for corrosion in a naturally aerated 1-N solution of sodium chloride. The condition of the metal/sodium chloride solution interface is studied by the method of electrochemical impedance spectroscopy. It is shown that the corrosion resistance of low-carbon steels can be raised by anode electrolytic-plasma saturation with nitrogen and carbon. Recommendations are given on the choice of carbonitriding modes for structural steels.

Combinations of fluorinated solvents with imide salts or methide salts for electrolytes

DOEpatents

Tikhonov, Konstantin; Yip, Ka Ki; Lin, Tzu-Yuan; Lei, Norman; Guerrero-Zavala, Guillermo; Kwong, Kristie W

2015-11-10

Provided are electrochemical cells and electrolytes used to build such cells. The electrolytes include imide salts and/or methide salts as well as fluorinated solvents capable of maintaining single phase solutions at between about -30.degree. C. to about 80.degree. C. The fluorinated solvents, such as fluorinated carbonates, fluorinated esters, and fluorinated esters, are less flammable than their non-fluorinated counterparts and improve safety characteristics of cells containing these solvents. The amount of fluorinated solvents in electrolytes may be between about 30% and 80% by weight not accounting weight of the salts. Linear and cyclic imide salts, such as LiN(SO.sub.2CF.sub.2CF.sub.3).sub.2, and LiN(SO.sub.2CF.sub.3).sub.2, as well as methide salts, such as LiC(SO.sub.2CF.sub.3).sub.3 and LiC(SO.sub.2CF.sub.2CF.sub.3).sub.3, may be used in these electrolytes. Fluorinated alkyl groups enhance solubility of these salts in the fluorinated solvents. In some embodiments, the electrolyte may also include a flame retardant, such as a phosphazene, and/or one or more ionic liquids.

Laboratory septic tank performance response to electrolytic stimulation.

PubMed

Zaveri, Rahul M; Flora, Joseph R V

2002-11-01

This research investigated the effects of electrolytic stimulation on the performance of two laboratory-scale septic tanks. The tanks were fed a synthetic solution that included cellulose, peptone trypticase, beef extract, and urea. After a baseline period with no passed current, currents ranging from 100 to 500 mA were passed through the electrodes. The chemical oxygen demand (COD) removal efficiency from the tanks improved when a current was passed, with higher removal efficiencies observed at higher levels of passed current. Hydrolytic reactions resulted in ammonia and phosphate levels in the tanks that were higher than the influent. At currents > 300 mA, these hydrolytic reactions were suppressed, resulting in phosphate levels similar to the influent and ammonia levels lower than the influent because of the settling of ammonia-containing components of the feed solution. A slight increase in nitrate levels was observed when a current was passed, indicating minimal stimulation of nitrification activity. Abiotic studies confirmed that the COD can be removed via electrolysis and the removal was proportional to the passed current. Under the conditions of this study, the primary benefit of electrolytic stimulation of the septic tank is enhanced COD removal.

Durability of the Li 1+xTi 2–xAl x(PO 4) 3 Solid Electrolyte in Lithium–Sulfur Batteries

DOE PAGES

Wang, Shaofei; Ding, Yu; Zhou, Guangmin; ...

2016-10-31

Adoption of cells with a solid-state electrolyte is a promising solution for eliminating the polysulfide shuttle problem in Li-S batteries. Among the various known lithium-ion conducting solid electrolytes, the sodium superionic conductor (NASICON)-type Li 1+xTi 2-xAl x(PO 4) 3 offers the advantage of good stability under ambient conditions and in contact with air. Accordingly, we present here a comprehensive assessment of the durability of Li 1+xTi 2-xAl x(PO 4) 3 in contact with polysulfide solution and in Li-S cells. Because of its high reduction potential (2.5 V vs Li/Li +), Li 1+xTi 2-xAl x(PO 4) 3 gets lithiated in contactmore » with lithium polysulfide solution and Li 2CO 3 is formed on the particle surface, blocking the interfacial lithium-ion transport between the liquid and solid-state electrolytes. After the lithium insertion into the NASICON framework, the crystal expands in an anisotropic way, weakening the crystal bonds, causing fissures and resultant cracks in the ceramic, corroding the grain boundaries by polysulfide solution, and leaving unfavorable pores. The assembly of pores creates a gateway for polysulfide diffusion from the cathode side to the anode side, causing an abrupt decline in cell performance. Therefore, the solid-state electrolytes need to have good chemical compatibility with both the electrode and electrolyte, long-term stability under harsh chemical environment, and highly stable grain boundaries.« less

Non-flammable polyphosphonate electrolytes

NASA Astrophysics Data System (ADS)

Dixon, Brian G.; Morris, R. Scott; Dallek, Steven

This research is directed towards the development of safe, and thermally stable polymeric electrolytes. Advanced electrolytes are described, including thermal test data, which are ionically highly conductive, and non-flammable. These novel multi-heteropolymer electrolytes represent a significant advance in the design of high-performance rechargeable lithium systems that possess superior safety and handling characteristics. Representative results are shown by the figures contained in this text. These DSC/TGA results compare a typical liquid carbonate-based electrolyte system, ethylene carbonate and ethyl methyl carbonate, with novel polyphosphonates as synthesized in this program. These tests were performed with the electrolytes in combination with lithium metal, and the impressive relative thermal stability of the phosphonates is apparent.

Urticaria due to polyethylene glycol-3350 and electrolytes for oral solution in a patient with jejunal nodular lymphoid hyperplasia

PubMed Central

Zhang, Hongfeng; Henry, Winoah A.; Chen, Lea Ann; Khashab, Mouen A.

2015-01-01

Both jejunal nodular lymphoid hyperplasia (NLH) and polyethylene glycol (PEG)-3350 hypersensitivity are extremely rare. We describe a 30-year-old female who had previously taken a PEG-3350 bowel preparation without adverse effects, and presented for evaluation of chronic diarrhea. An upper and lower gastrointestinal endoscopy, and small bowel series were scheduled. PEG-3350 and electrolytes for oral solution was prescribed for bowel cleansing. During consumption of the bowel preparation she developed urticarial hypersensitivity. An alternative bowel preparation was used. Colonoscopy and upper endoscopy were normal, but small bowel series revealed innumerable sand-like lucencies in the jejunum. NLH was confirmed on biopsy from antegrade enteroscopy. This is the first case report on the pathological jejunal NLH in association with the PEG-3350 urticarial hypersensitivity. The potential pathophysiological etiology of this association is discussed. PMID:25608714

Characterization of plasticized PEO-PAM blend polymer electrolyte system

NASA Astrophysics Data System (ADS)

Dave, Gargi; Kanchan, Dinesh

2017-05-01

Present study reports characterization studies of NaCF3SO3 based PEO-PAM Blend Polymer Electrolyte (BPE) system with varying amount of EC+PC as plasticizer prepared by solution cast technique. Structural analysis and surface topography have been performed using FTIR and SEM studies. To understand, thermal properties, DSC studies have been undertaken in the present paper

Facile synthesis of Li2S-P2S5 glass-ceramics electrolyte with micron range particles for all-solid-state batteries via a low-temperature solution technique (LTST)

NASA Astrophysics Data System (ADS)

Choi, Sunho; Lee, Sewook; Park, Jongyeop; Nichols, William T.; Shin, Dongwook

2018-06-01

A lithium ion conductive 75Li2Sṡ25P2S5 glass-ceramics electrolyte is, for the first time, successfully synthesized via a new low-temperature solution technique (LTST) and compared to the conventional mechanical-milling technique. Both samples are composed of the highly lithium ion conductive thio-LISICON III analog phase. Due to the uniform dispersion of reactants in an organic liquid, the use of LTST produced significantly smaller and more uniform particle sizes (2.2 ± 1.68 μm) resulting in a 6.5 times higher specific surface area compared to the mechanically-milled sample. A pronounced enhancement of both the rate capability and cyclability is demonstrated for the LTST solid electrolyte sample due to the more intimate contact with the LiCoO2 active material. Furthermore, the LTST sample shows excellent electrochemical stability throughout the potential range of -1 to 5 V. These results suggest that the proposed technique using the optimized LTST process is promising for the preparation of 75Li2Sṡ25P2S5 solid electrolytes for use in advanced Li-ion batteries.

Reducing background contributions in fluorescence fluctuation time-traces for single-molecule measurements in solution.

PubMed

Földes-Papp, Zeno; Liao, Shih-Chu Jeff; You, Tiefeng; Barbieri, Beniamino

2009-08-01

We first report on the development of new microscope means that reduce background contributions in fluorescence fluctuation methods: i) excitation shutter, ii) electronic switches, and iii) early and late time-gating. The elements allow for measuring molecules at low analyte concentrations. We first found conditions of early and late time-gating with time-correlated single-photon counting that made the fluorescence signal as bright as possible compared with the fluctuations in the background count rate in a diffraction-limited optical set-up. We measured about a 140-fold increase in the amplitude of autocorrelated fluorescence fluctuations at the lowest analyte concentration of about 15 pM, which gave a signal-to-background advantage of more than two-orders of magnitude. The results of this original article pave the way for single-molecule detection in solution and in live cells without immobilization or hydrodynamic/electrokinetic focusing at longer observation times than are currently available.

Electrolyte salts for nonaqueous electrolytes

DOEpatents

Amine, Khalil; Zhang, Zhengcheng; Chen, Zonghai

2012-10-09

Metal complex salts may be used in lithium ion batteries. Such metal complex salts not only perform as an electrolyte salt in a lithium ion batteries with high solubility and conductivity, but also can act as redox shuttles that provide overcharge protection of individual cells in a battery pack and/or as electrolyte additives to provide other mechanisms to provide overcharge protection to lithium ion batteries. The metal complex salts have at least one aromatic ring. The aromatic moiety may be reversibly oxidized/reduced at a potential slightly higher than the working potential of the positive electrode in the lithium ion battery. The metal complex salts may also be known as overcharge protection salts.

Electrolyte effects in a model of proton discharge on charged electrodes

NASA Astrophysics Data System (ADS)

Wiebe, Johannes; Kravchenko, Kateryna; Spohr, Eckhard

2015-01-01

We report results on the influence of NaCl electrolyte dissolved in water on proton discharge reactions from aqueous solution to charged platinum electrodes. We have extended a recently developed combined proton transfer/proton discharge model on the basis of empirical valence bond theory to include NaCl solutions with several different concentrations of cations and anions, both stoichiometric (1:1) compositions and non-stoichiometric ones with an excess of cations. The latter solutions partially screen the electrostatic potential from the surface charge of the negatively charged electrode. 500-1000 trajectories of a discharging proton were integrated by molecular dynamics simulations until discharge occurred, or for at most 1.5 ns. The results show a strong dependence on ionic strength, but only a weak dependence on the screening behavior, when comparing stoichiometric and non-stoichiometric solutions. Overall, the Na+ cations exert a more dominant effect on the discharge reaction, which we argue is likely due to the very rigid arrangements of the cations on the negatively polarized electrode surface. Thus, our model predicts, for the given and very high negative surface charge densities, the fastest discharge reaction for pure water, but obviously cannot take into account the fact that such high charge densities are even more out of reach experimentally than for higher electrolyte concentrations.

The application of electrolytic photoetching and photopolishing to AISI 304 stainless steel and the electrolytic photoetching of amorphous cobalt alloy

NASA Astrophysics Data System (ADS)

Thomaz, Marita Duarte Canhao da Silva Pereira Fernandes

The results presented cover broad aspects of a quantitative investigation into the elecrolytic etching and polishing of metals and alloys through photographically produced dielectric stencils (Photoresists). A study of the potential field generated between a cathode and relatively smaller anode sites as those defined by a dielectric stencil was carried out. Numerical, analytical and graphical methods yielded answers to the factors determining lateral dissolution (undercut) at the anode/stencil interface. A quasi steady state numerical model simulating the transient behavior of the partially masked electrodes undergoing dissolution was obtained. AISI 304 stainless steel was electrolytically photoetched in 10% w/w HCl electrolyte. The optimised process parameters were utilised for quantifying the effects of galvanostatic etching of the anode as that defined by a relatively narrow adherent resist stencil. Stainless steel was also utilised in investigating electrolytic photopolishing. A polishing electrolyte (orthophosphoric acid-glycerol) was modified by the addition of a surfactant which yielded surface texture values of 70nm (Ra) and high levels of specular reflectance. These results were used in the production of features upon the metal surface through photographically produced precision stencils. The process was applied to the production of edge filters requiring high quality surface textures in precision recesses. Some of the new amorphous material exhibited high resistance to dissolution in commercially used spray etching formulations. One of these materials is a cobalt based alloy produced by chill block spinning. This material was also investigated and electro etched in 10% w/w HCl solution. Although passivity was not overcome, by selecting suitable operating parameters the successful electro photoetching of precision magnetic recording head laminations was achieved. Similarly, a polycrystalline nickel based alloy also exhibiting passivity in commercially used

Effects of electrode distance and nature of electrolyte on the diameter of titanium dioxide nanotube

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abbasi, S., E-mail: sum.abbasi@gmail.com; Mohamed, N. M., E-mail: noranimuti-mohamed@petronas.com.my; Singh, B. S. M., E-mail: balbir@petronas.com.my

2015-07-22

The titanium nanotubes were synthesized using viscous electrolytes consisting of ethylene glycol and non-viscous electrolytes consisting of aqueous solution of hydrofluoric acid. Sodium fluoride and ammonium fluoride were utilized as the source of fluorine ions. The samples were then characterized by field emission scanning electron microscope (FE-SEM). Their morphologies were investigated under different anodic potentials and various electrolyte compositions. It was found out that nanotubes can be obtained in fluoride ions and morphology is dependent on various parameters like anodic potential, time, electrolyte composition and the effects by varying the distance between the electrodes on the morphology was also investigated.more » It was found that by altering the distance between the electrodes, change in the diameter and the porosity was observed.« less

Lithium ion conducting electrolytes

DOEpatents

Angell, Charles Austen; Liu, Changle; Xu, Kang; Skotheim, Terje A.

1999-01-01

The present invention relates generally to highly conductive alkali-metal ion non-crystalline electrolyte systems, and more particularly to novel and unique molten (liquid), rubbery, and solid electrolyte systems which are especially well suited for use with high current density electrolytic cells such as primary and secondary batteries.

Solid polymer electrolyte compositions

DOEpatents

Garbe, James E.; Atanasoski, Radoslav; Hamrock, Steven J.; Le, Dinh Ba

2001-01-01

An electrolyte composition is featured that includes a solid, ionically conductive polymer, organically modified oxide particles that include organic groups covalently bonded to the oxide particles, and an alkali metal salt. The electrolyte composition is free of lithiated zeolite. The invention also features cells that incorporate the electrolyte composition.

Electrolytic purification of metals

DOEpatents

Bowman, Kenneth A.

1980-01-01

A method of electrolytically separating metal from impurities comprises providing the metal and impurities in a molten state in a container having a porous membrane therein, the membrane having a thickness in the range of about 0.01 to 0.1 inch, being capable of containing the molten metal in the container, and being permeable by a molten electrolyte. The metal is electrolytically transferred through the membrane to a cathode in the presence of the electrolyte for purposes of separating or removing impurities from the metal.

A simple model of fluid flow and electrolyte balance in the body

NASA Technical Reports Server (NTRS)

White, R. J.; Neal, L.

1973-01-01

The model is basically a three-compartment model, the three compartments being the plasma, interstitial fluid and cellular fluid. Sodium, potassium, chloride and urea are the only major solutes considered explicitly. The control of body water and electrolyte distribution is affected via drinking and hormone levels. Basically, the model follows the effect of various oral input water loads on solute and water distribution throughout the body.

Efficacy and Safety of Combined Oral and Enema Therapy Using Polyethylene Glycol 3350-Electrolyte for Disimpaction in Pediatric Constipation.

PubMed

Yoo, Taeyeon; Bae, Sun Hwan

2017-12-01

We evaluated the efficacy and safety of combined oral and enema therapy using polyethylene glycol (PEG) 3350 with electrolyte solution for disimpaction in hospitalized children. We retrospectively studied 28 children having functional constipation who received inpatient treatment between 2008 and 2016. The amount of oral PEG 3350 electrolyte solution administered was 50-70 mL/kg/d (PEG 3350, 3-4.1 g/kg/d), and an enema solution was administered 1-2 times a day as a single dose of 15-25 mL/kg (PEG 3350, 0.975-1.625 g/kg/d). A colon transit time (CTT) test based on the Metcalf protocol was performed in some patients. Administration of oral and enema doses of PEG 3350 electrolyte solution showed 2.1±0.3 times and 2.9±0.4 times, respectively. After disimpaction, the frequency of defecation increased from 2.2±0.3 per week to once a day (1.1±0.1 per day). The number of patients who complained of abdominal pain was reduced from 15 (53.6%) to 4 (14.3%). Before hospitalization, nine patients underwent a CTT test, and 5 of 9 patients (55.6%) were classified as belonging to a group showing abnormalities. And in some patients, mild adverse effects were noted. We examined electrolytes and osmolality before and after disimpaction in 16 of 28 patients, and no abnormalities were noted. In terms of therapeutic efficacy and safety, combined oral and enema therapy using high-dose PEG 3350 with electrolytes is considered superior to conventional oral monotherapy or combined oral and enema therapy on an outpatient basis.

Electrode-Electrolyte Interfaces in Lithium-Sulfur Batteries with Liquid or Inorganic Solid Electrolytes.

PubMed

Yu, Xingwen; Manthiram, Arumugam

2017-11-21

Electrode-electrolyte interfacial properties play a vital role in the cycling performance of lithium-sulfur (Li-S) batteries. The issues at an electrode-electrolyte interface include electrochemical and chemical reactions occurring at the interface, formation mechanism of interfacial layers, compositional/structural characteristics of the interfacial layers, ionic transport across the interface, and thermodynamic and kinetic behaviors at the interface. Understanding the above critical issues is paramount for the development of strategies to enhance the overall performance of Li-S batteries. Liquid electrolytes commonly used in Li-S batteries bear resemblance to those employed in traditional lithium-ion batteries, which are generally composed of a lithium salt dissolved in a solvent matrix. However, due to a series of unique features associated with sulfur or polysulfides, ether-based solvents are generally employed in Li-S batteries rather than simply adopting the carbonate-type solvents that are generally used in the traditional Li + -ion batteries. In addition, the electrolytes of Li-S batteries usually comprise an important additive, LiNO 3 . The unique electrolyte components of Li-S batteries do not allow us to directly take the interfacial theories of the traditional Li + -ion batteries and apply them to Li-S batteries. On the other hand, during charging/discharging a Li-S battery, the dissolved polysulfide species migrate through the battery separator and react with the Li anode, which magnifies the complexity of the interfacial problems of Li-S batteries. However, current Li-S battery development paths have primarily been energized by advances in sulfur cathodes. Insight into the electrode-electrolyte interfacial behaviors has relatively been overshadowed. In this Account, we first examine the state-of-the-art contributions in understanding the solid-electrolyte interphase (SEI) formed on the Li-metal anode and sulfur cathode in conventional liquid-electrolyte

Electrochemically stable electrolytes

DOEpatents

Angell, Charles Austen; Zhang, Sheng-Shui; Xu, Kang

1999-01-01

This invention relates generally to inorganic ionic liquids which function as electrolytes and do not crystallize at ambient temperature. More specifically, this invention is directed to quasi-salt inorganic ionic liquids which comprise the reaction product of a strong Lewis acid with an inorganic halide-donating molecule. This invention is further directed to quasi-salt inorganic ionic liquid mixtures which comprise combinations of electrolyte additives and quasi-salt inorganic ionic liquids. These quasi-salt inorganic ionic liquid mixtures are useful electrolytes.

Electrochemically stable electrolytes

DOEpatents

Angell, C.A.; Zhang, S.S.; Xu, K.

1999-01-05

This invention relates generally to inorganic ionic liquids which function as electrolytes and do not crystallize at ambient temperature. More specifically, this invention is directed to quasi-salt inorganic ionic liquids which comprise the reaction product of a strong Lewis acid with an inorganic halide-donating molecule. This invention is further directed to quasi-salt inorganic ionic liquid mixtures which comprise combinations of electrolyte additives and quasi-salt inorganic ionic liquids. These quasi-salt inorganic ionic liquid mixtures are useful electrolytes. 16 figs.

Operating mechanisms of electrolytes in magnesium ion batteries: chemical equilibrium, magnesium deposition, and electrolyte oxidation.

PubMed

Kim, Dong Young; Lim, Younhee; Roy, Basab; Ryu, Young-Gyoon; Lee, Seok-Soo

2014-12-21

Since the early nineties there have been a number of reports on the experimental development of Mg electrolytes based on organo/amide-magnesium chlorides and their transmetalations. However, there are no theoretical papers describing the underlying operating mechanisms of Mg electrolytes, and there is no clear understanding of these mechanisms. We have therefore attempted to clarify the operating mechanisms of Mg electrolytes by studying the characteristics of Mg complexes, solvation, chemical equilibrium, Mg-deposition processes, electrolyte-oxidation processes, and oxidative degradation mechanism of RMgCl-based electrolytes, using ab initio calculations. The formation and solvation energies of Mg complexes highly depend on the characteristics of R groups. Thus, changes in R groups of RMgCl lead to changes in the equilibrium position and the electrochemical reduction and oxidation pathways and energies. We first provide a methodological scheme for calculating Mg reduction potential values in non-aqueous electrolytes and electrochemical windows. We also describe a strategy for designing Mg electrolytes to maximize the electrochemical windows and oxidative stabilities. These results will be useful not only for designing improved Mg electrolytes, but also for developing new electrolytes in the future.

Treatment of electrochemical cell components with lithium tetrachloroaluminate (LiAlCl.sub.4) to promote electrolyte wetting

DOEpatents

Eberhart, James G.; Battles, James E.

1980-01-01

Electrochemical cell components such as interelectrode separators, retaining screens and current collectors are contacted with lithium tetrachloroaluminate prior to contact with molten electrolytic salt to improve electrolyte wetting. The LiAlCl.sub.4 can be applied in powdered, molten or solution form but, since this material has a lower melting point than the electrolytic salt used in high-temperature cells, the powdered LiAlCl.sub.4 forms a molten flux prior to contact by the molten electrolyte when both materials are initially provided in solid form. Components of materials such as boron nitride and other materials which are difficult to wet with molten salts are advantageously treated by this process.

Enhancing electrochemical intermediate solvation through electrolyte anion selection to increase nonaqueous Li-O2 battery capacity.

PubMed

Burke, Colin M; Pande, Vikram; Khetan, Abhishek; Viswanathan, Venkatasubramanian; McCloskey, Bryan D

2015-07-28

Among the "beyond Li-ion" battery chemistries, nonaqueous Li-O2 batteries have the highest theoretical specific energy and, as a result, have attracted significant research attention over the past decade. A critical scientific challenge facing nonaqueous Li-O2 batteries is the electronically insulating nature of the primary discharge product, lithium peroxide, which passivates the battery cathode as it is formed, leading to low ultimate cell capacities. Recently, strategies to enhance solubility to circumvent this issue have been reported, but rely upon electrolyte formulations that further decrease the overall electrochemical stability of the system, thereby deleteriously affecting battery rechargeability. In this study, we report that a significant enhancement (greater than fourfold) in Li-O2 cell capacity is possible by appropriately selecting the salt anion in the electrolyte solution. Using (7)Li NMR and modeling, we confirm that this improvement is a result of enhanced Li(+) stability in solution, which, in turn, induces solubility of the intermediate to Li2O2 formation. Using this strategy, the challenging task of identifying an electrolyte solvent that possesses the anticorrelated properties of high intermediate solubility and solvent stability is alleviated, potentially providing a pathway to develop an electrolyte that affords both high capacity and rechargeability. We believe the model and strategy presented here will be generally useful to enhance Coulombic efficiency in many electrochemical systems (e.g., Li-S batteries) where improving intermediate stability in solution could induce desired mechanisms of product formation.

Thiocyanates as attractive redox-active electrolytes for high-energy and environmentally-friendly electrochemical capacitors.

PubMed

Gorska, Barbara; Bujewska, Paulina; Fic, Krzysztof

2017-03-15

This manuscript reports on the novel insight into the development of high voltage carbon/carbon electrochemical capacitors operating in aqueous solutions of alkali metals and ammonium thiocyanates (KSCN, NaSCN, LiSCN, and NH 4 SCN). The effect of salt concentration, electrode porosity and current collectors on the capacitance value, system stability, and power performance has been investigated. Therefore, thiocyanate-based electrolytes were recognized as cheap and highly conductive electrolytic solutions (up to 401 mS cm -1 for NH 4 SCN at RT) allowing a cell voltage of 1.6 V in a symmetric carbon/carbon system to be achieved. At the same time, they display an attractive redox activity, enhancing the energy of the device with a good performance during cycling.

Research Progress towards Understanding the Unique Interfaces between Concentrated Electrolytes and Electrodes for Energy Storage Applications

PubMed Central

Lochala, Joshua A.; Kwok, Alexander; Deng, Zhiqun Daniel

2017-01-01

The electrolyte is an indispensable component in all electrochemical energy storage and conversion devices with batteries being a prime example. While most research efforts have been pursued on the materials side, the progress for the electrolyte is slow due to the decomposition of salts and solvents at low potentials, not to mention their complicated interactions with the electrode materials. The general properties of bulk electrolytes such as ionic conductivity, viscosity, and stability all affect the cell performance. However, for a specific electrochemical cell in which the cathode, anode, and electrolyte are optimized, it is the interface between the solid electrode and the liquid electrolyte, generally referred to as the solid electrolyte interphase (SEI), that dictates the rate of ion flow in the system. The commonly used electrolyte is within the range of 1–1.2 m based on the prior optimization experience, leaving the high concentration region insufficiently recognized. Recently, electrolytes with increased concentration (>1.0 m) have received intensive attention due to quite a few interesting discoveries in cells containing concentrated electrolytes. The formation mechanism and the nature of the SEI layers derived from concentrated electrolytes could be fundamentally distinct from those of the traditional SEI and thus enable unusual functions that cannot be realized using regular electrolytes. In this article, we provide an overview on the recent progress of high concentration electrolytes in different battery chemistries. The experimentally observed phenomena and their underlying fundamental mechanisms are discussed. New insights and perspectives are proposed to inspire more revolutionary solutions to address the interfacial challenges. PMID:28852621

Research Progress towards Understanding the Unique Interfaces between Concentrated Electrolytes and Electrodes for Energy Storage Applications

DOE PAGES

Zheng, Jianming; Lochala, Joshua A.; Kwok, Alexander; ...

2017-03-31

The electrolyte is an indispensable component in all electrochemical energy storage and conversion devices, for example, batteries. While most research efforts have been pursued on the materials side, the progress for the electrolyte is slow due to the decomposition of salts and solvents at low potentials, not to mention their complicated interactions with the electrode materials. The general properties of bulk electrolytes such as ionic conductivity, viscosity, and stability all affect the cell performance. However, for a specific electrochemical cell in which the cathode, anode and electrolyte are optimized, it is the interface between the solid electrode and the liquidmore » electrolyte, generally referred to as the solid electrolyte interphase (SEI), that dictates the rate of ion flow in the system. The commonly used electrolyte is within the range of 1-1.2 M based on the prior optimization experience, leaving the high concentration region insufficiently recognized. Recently, electrolytes with increased concentration (> 1.0 M) have received additional attention due to quite a few interesting discoveries in cells containing concentrated electrolytes. The formation mechanism and the nature of the SEI layers derived from concentrated electrolytes could be fundamentally different from those of the traditional SEI and thus enable unusual functions that cannot be realized using regular electrolytes. In this article, we provide an overview on the recent progress of high concentration electrolytes in different battery chemistries. The experimentally observed phenomena and their underlying fundamental mechanism are discussed. As a result, new insights and perspectives are proposed to inspire more revolutionary solutions to address the interfacial challenges.« less

Research Progress towards Understanding the Unique Interfaces between Concentrated Electrolytes and Electrodes for Energy Storage Applications.

PubMed

Zheng, Jianming; Lochala, Joshua A; Kwok, Alexander; Deng, Zhiqun Daniel; Xiao, Jie

2017-08-01

The electrolyte is an indispensable component in all electrochemical energy storage and conversion devices with batteries being a prime example. While most research efforts have been pursued on the materials side, the progress for the electrolyte is slow due to the decomposition of salts and solvents at low potentials, not to mention their complicated interactions with the electrode materials. The general properties of bulk electrolytes such as ionic conductivity, viscosity, and stability all affect the cell performance. However, for a specific electrochemical cell in which the cathode, anode, and electrolyte are optimized, it is the interface between the solid electrode and the liquid electrolyte, generally referred to as the solid electrolyte interphase (SEI), that dictates the rate of ion flow in the system. The commonly used electrolyte is within the range of 1-1.2 m based on the prior optimization experience, leaving the high concentration region insufficiently recognized. Recently, electrolytes with increased concentration (>1.0 m) have received intensive attention due to quite a few interesting discoveries in cells containing concentrated electrolytes. The formation mechanism and the nature of the SEI layers derived from concentrated electrolytes could be fundamentally distinct from those of the traditional SEI and thus enable unusual functions that cannot be realized using regular electrolytes. In this article, we provide an overview on the recent progress of high concentration electrolytes in different battery chemistries. The experimentally observed phenomena and their underlying fundamental mechanisms are discussed. New insights and perspectives are proposed to inspire more revolutionary solutions to address the interfacial challenges.

Research Progress towards Understanding the Unique Interfaces between Concentrated Electrolytes and Electrodes for Energy Storage Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Jianming; Lochala, Joshua A.; Kwok, Alexander

The electrolyte is an indispensable component in all electrochemical energy storage and conversion devices, for example, batteries. While most research efforts have been pursued on the materials side, the progress for the electrolyte is slow due to the decomposition of salts and solvents at low potentials, not to mention their complicated interactions with the electrode materials. The general properties of bulk electrolytes such as ionic conductivity, viscosity, and stability all affect the cell performance. However, for a specific electrochemical cell in which the cathode, anode and electrolyte are optimized, it is the interface between the solid electrode and the liquidmore » electrolyte, generally referred to as the solid electrolyte interphase (SEI), that dictates the rate of ion flow in the system. The commonly used electrolyte is within the range of 1-1.2 M based on the prior optimization experience, leaving the high concentration region insufficiently recognized. Recently, electrolytes with increased concentration (> 1.0 M) have received additional attention due to quite a few interesting discoveries in cells containing concentrated electrolytes. The formation mechanism and the nature of the SEI layers derived from concentrated electrolytes could be fundamentally different from those of the traditional SEI and thus enable unusual functions that cannot be realized using regular electrolytes. In this article, we provide an overview on the recent progress of high concentration electrolytes in different battery chemistries. The experimentally observed phenomena and their underlying fundamental mechanism are discussed. As a result, new insights and perspectives are proposed to inspire more revolutionary solutions to address the interfacial challenges.« less

Graphene-based supercapacitors in the parallel-plate electrode configuration: ionic liquids versus organic electrolytes.

PubMed

Shim, Youngseon; Kim, Hyung J; Jung, Younjoon

2012-01-01

Supercapacitors with two single-sheet graphene electrodes in the parallel plate geometry are studied via molecular dynamics (MD) computer simulations. Pure 1-ethyl-3-methylimidazolium tetrafluoroborate (EMI+BF4-) and a 1.1 M solution of EMI+BF4- in acetonitrile are considered as prototypes of room-temperature ionic liquids (RTILs) and organic electrolytes. Electrolyte structure, charge density and associated electric potential are investigated by varying the charges and separation of the two electrodes. Multiple charge layers formed in the electrolytes in the vicinity of the electrodes are found to screen the electrode surface charge almost completely. As a result, the supercapacitors show nearly an ideal electric double layer behavior, i.e., the electric potential exhibits essentially a plateau behavior in the entire electrolyte region except for sharp changes in screening zones very close to the electrodes. Due to its small size and large charge separation, BF4- is considerably more efficient in shielding electrode charges than EMI+. In the case of the acetonitrile solution, acetonitrile also plays an important role by aligning its dipoles near the electrodes; however, the overall screening mainly arises from ions. Because of the disparity of shielding efficiency between cations and anions, the capacitance of the positively-charged anode is significantly larger than that of the negatively-charged cathode. Therefore, the total cell capacitance in the parallel plate configuration is primarily governed by the cathode. Ion conductivity obtained via the Green-Kubo (GK) method is found to be largely independent of the electrode surface charge. Interestingly, EMI+BF4- shows higher GK ion conductivity than the 1.1 M acetonitrile solution between two parallel plate electrodes.

Influence of electrolytes on growth, phototropism, nutation and surface potential in etiolated cucumber seedlings

NASA Technical Reports Server (NTRS)

Spalding, E. P.; Cosgrove, D. J.

1993-01-01

A variety of electrolytes (10-30 mol m-3) increased the relative growth rate of etiolated cucumber (Cucumis sativus L. cv. Burpee's Pickler) hypocotyls by 20-50% relative to water-only controls. The nonelectrolyte mannitol inhibited growth by 10%. All salts tested were effective, regardless of chemical composition or valence. Measurements of cell-sap osmolality ruled out an osmotic mechanism for the growth stimulation by electrolytes. This, and the nonspecificity of the response, indicate that an electrical property of the solutions was responsible for their growth-stimulating activity. Measurements of surface electrical potential supported this reasoning. Treatment with electrolytes also enhanced nutation and altered the pattern of phototropic curvature development. A novel analytical method for quantitating these effects on growth was developed. The evidence indicates that electrolytes influence an electrophysiological parameter that is involved in the control of cell expansion and the coordination of growth underlying tropisms and nutations.

A randomized, controlled, double-blind trial of the adjunct use of Clebopride in polyethylene glycol electrolyte (PEG) solution for colonoscopy preparation.

PubMed

Abdullah, Murdani; Rani, A Aziz; Fauzi, Achmad; Syam, Ari Fahrial; Makmun, Dadang; Simadibrata, Marcellus; Manan, Chudahman; Harjodisastro, Daldiyono

2010-01-01

To study the benefit of Clebopride as an adjuvant in polyethylene glycol electrolyte (PEG) solution for colonoscopy preparation. Eighty one adult patients who underwent colonoscopy examination were recruited in this randomized double blind controlled study. First group received PEG and placebo, whereas second group received PEG and Clebopride. Two litres of PEG was taken at night before colonoscopy. The acceptability and tolerability of bowel preparation were assessed through interview method. The efficacy of bowel preparation was assessed using Aronchick's Criteria. In terms of acceptability, 64 patients (31 patients from placebo group vs 33 patients from Clebopride group) were able to drink two litres of PEG solution. Sixty patients (29 patients from placebo group and 31 patients from Clebopride group) were willing to accept PEG solution for their next bowel preparation. On the term of tolerability, nausea, abdominal distension, and borborygmus were more frequent in the placebo group (34.2% vs 27.9%; 44.7% vs 32.6%; 26.3% vs 4.6% respectively). However, only the difference at the incidence of borborygmus that was statistically significant (p<0.05). On the terms of efficacy, both groups showed a comparable bowel preparation quality with 88.4% of bowel preparation in Clebopride group and 81.6% of bowel preparation in placebo group were optimal (p = 0.585). The adjunct use of Clebopride in PEG solution for colonoscopy preparations tends to increase the acceptability, tolerability, and efficacy. The presence of borborygmus was significantly lower in the Clebopride group.

Developing New Electrolytes for Advanced Li-ion Batteries

NASA Astrophysics Data System (ADS)

McOwen, Dennis Wayne

The use of renewable energy sources is on the rise, as new energy generating technologies continue to become more efficient and economical. Furthermore, the advantages of an energy infrastructure which relies more on sustainable and renewable energy sources are becoming increasingly apparent. The most readily available of these renewable energy sources, wind and solar energy in particular, are naturally intermittent. Thus, to enable the continued expansion and widespread adoption of renewable energy generating technology, a cost-effective energy storage system is essential. Additionally, the market for electric/hybrid electric vehicles, which both require efficient energy storage, continues to grow as more consumers seek to reduce their consumption of gasoline. These vehicles, however, remain quite expensive, due primarily to costs associated with storing the electrical energy. High-voltage and thermally stable Li-ion battery technology is a promising solution for both grid-level and electric vehicle energy storage. Current limitations in materials, however, limit the energy density and safe operating temperature window of the battery. Specifically, the state-of-the-art electrolyte used in Li-ion batteries is not compatible with recently developed high-voltage positive electrodes, which are one of the most effectual ways of increasing the energy density. The electrolyte is also thermally unstable above 50 °C, and prone to thermal runaway reaction if exposed to prolonged heating. The lithium salt used in such electrolytes, LiPF6, is a primary contributor to both of these issues. Unfortunately, an improved lithium salt which meets the myriad property requirements for Li-ion battery electrolytes has eluded researchers for decades. In this study, a renewed effort to find such a lithium salt was begun, using a recently developed methodology to rapidly screen for desirable properties. Four new lithium salts and one relatively new but uncharacterized lithium salt were

Composite Solid Electrolyte For Lithium Cells

NASA Technical Reports Server (NTRS)

Peled, Emmanuel; Nagasubramanian, Ganesan; Halpert, Gerald; Attia, Alan I.

1994-01-01

Composite solid electrolyte material consists of very small particles, each coated with thin layer of Lil, bonded together with polymer electrolyte or other organic binder. Material offers significant advantages over other solid electrolytes in lithium cells and batteries. Features include high ionic conductivity and strength. Composite solid electrolyte expected to exhibit flexibility of polymeric electrolytes. Polymer in composite solid electrolyte serves two purposes: used as binder alone, conduction taking place only in AI2O3 particles coated with solid Lil; or used as both binder and polymeric electrolyte, providing ionic conductivity between solid particles that it binds together.

Improved Low-Temperature Performance of Li-Ion Cells Using New Electrolytes

NASA Technical Reports Server (NTRS)

Smart, Marshall C.; Buga, Ratnakumar V.; Gozdz, Antoni S.; Mani, Suresh

2010-01-01

As part of the continuing efforts to develop advanced electrolytes to improve the performance of lithium-ion cells, especially at low temperatures, a number of electrolyte formulations have been developed that result in improved low-temperature performance (down to 60 C) of 26650 A123Systems commercial lithium-ion cells. The cell type/design, in which the new technology has been demonstrated, has found wide application in the commercial sector (i.e., these cells are currently being used in commercial portable power tools). In addition, the technology is actively being considered for hybrid electric vehicle (HEV) and electric vehicle (EV) applications. In current work, a number of low-temperature electrolytes have been developed based on advances involving lithium hexafluorophosphate-based solutions in carbonate and carbonate + ester solvent blends, which have been further optimized in the context of the technology and targeted applications. The approaches employed, which include the use of ternary mixtures of carbonates, the use of ester co-solvents [e.g., methyl butyrate (MB)], and optimized lithium salt concentrations (e.g., LiPF6), were compared with the commercial baseline electrolyte, as well as an electrolyte being actively considered for DoE HEV applications and previously developed by a commercial enterprise, namely LiPF6 in ethylene carbonate (EC) + ethyl methyl carbonate (EMC)(30:70%).

Solvothermal synthesis of gallium-indium-zinc-oxide nanoparticles for electrolyte-gated transistors.

PubMed

Santos, Lídia; Nunes, Daniela; Calmeiro, Tomás; Branquinho, Rita; Salgueiro, Daniela; Barquinha, Pedro; Pereira, Luís; Martins, Rodrigo; Fortunato, Elvira

2015-01-14

Solution-processed field-effect transistors are strategic building blocks when considering low-cost sustainable flexible electronics. Nevertheless, some challenges (e.g., processing temperature, reliability, reproducibility in large areas, and cost effectiveness) are requirements that must be surpassed in order to achieve high-performance transistors. The present work reports electrolyte-gated transistors using as channel layer gallium-indium-zinc-oxide nanoparticles produced by solvothermal synthesis combined with a solid-state electrolyte based on aqueous dispersions of vinyl acetate stabilized with cellulose derivatives, acrylic acid ester in styrene and lithium perchlorate. The devices fabricated using this approach display a ION/IOFF up to 1 × 10(6), threshold voltage (VTh) of 0.3-1.9 V, and mobility up to 1 cm(2)/(V s), as a function of gallium-indium-zinc-oxide ink formulation and two different annealing temperatures. These results validates the usage of electrolyte-gated transistors as a viable and promising alternative for nanoparticle based semiconductor devices as the electrolyte improves the interface and promotes a more efficient step coverage of the channel layer, reducing the operating voltage when compared with conventional dielectrics gating. Moreover, it is shown that by controlling the applied gate potential, the operation mechanism of the electrolyte-gated transistors can be modified from electric double layer to electrochemical doping.

Application of refractometry to quality assurance monitoring of parenteral nutrition solutions.

PubMed

Chang, Wei-Kuo; Chao, You-Chen; Yeh, Ming-Kung

2008-01-01

Parenteral nutrition (PN) solution contains various concentrations of dextrose, amino acids, lipids, vitamins, electrolytes, and trace elements. Incorrect preparation of PN solution could lead to patient death. In this study we used the refractive index as a quality assurance tool to monitor the preparation of PN solution. Refractive indices of single nutrient components and PN solutions consisting of various concentrations of dextrose, amino acids, electrolytes, and lipids were measured. A mathematical equation and its linear plot were generated then used to predict the refractive index of the PN solution. The best-fit refractive index for PN solution (i.e., the predicted refractive index)=0.9798x(% dextrose)+1.2889x(% amino acids)+1.1017x(% lipids)+0.9440x(% sum of the electrolytes)+0.5367 (r2=0.99). This equation was validated by comparing the measured refractive indices of 500 clinical PN solutions to their predicted refractive indices. We found that 2 of the 500 prepared samples (0.4%) had less than the predicted refractive index (<95%). Refractive index can be used as a reliable quality assurance tool for monitoring PN preparation. Such information can be obtained at the bedside and used to confirm the accuracy of the PN solution composition.

Convenient UV-spectrophotometric determination of citrates in aqueous solutions with applications in the pharmaceutical analysis of oral electrolyte formulations.

PubMed

Krukowski, Sylwester; Karasiewicz, Mateusz; Kolodziejski, Waclaw

2017-07-01

Herein, we present a convenient method for quantitative spectrophotometric determination of citrate ions in aqueous solutions in the middle-UV range. It involves measuring the absorbance of citric acid at 209 nm under suppressed dissociation at pH < 1.0 in the presence of hydrochloric acid. Validation of the method was performed according to the guidelines of the International Conference on Harmonization. A very good linear dependence of the absorbance on concentration (r 2  = 0.9999) was obtained in a citrate concentration range of 0.5-5.0 mmol/L. This method is characterized by excellent precision and accuracy; the coefficient of variation in each case is below the maximal permissible value (%RSD < 2). The proposed analytical procedure has been successfully applied to the determination of citrates in oral electrolyte formulations. Copyright © 2017. Published by Elsevier B.V.

A new ether-based electrolyte for dendrite-free lithium-metal based rechargeable batteries

PubMed Central

Miao, Rongrong; Yang, Jun; Xu, Zhixin; Wang, Jiulin; Nuli, Yanna; Sun, Limin

2016-01-01

A new ether-based electrolyte to match lithium metal electrode is prepared by introducing 1, 4-dioxane as co-solvent into lithium bis(fluorosulfonyl)imide/1,2-dimethoxyethane solution. Under the synergetic effect of solvents and salt, this simple liquid electrolyte presents stable Li cycling with dendrite-free Li deposition even at relatively high current rate, high coulombic efficiency of ca. 98%, and good anodic stability up to ~4.87 V vs Li RE. Its excellent performance will open up a new possibility for high energy-density rechargeable Li metal battery system. PMID:26878890

A SERS characterization of the stability of polythionates at the gold-electrolyte interface

NASA Astrophysics Data System (ADS)

Mirza, Jeff; Smith, Scott R.; Baron, Janet Y.; Choi, Yeonuk; Lipkowski, Jacek

2015-01-01

A gold nanorod (AuNR) array electrode was employed to record SERS spectra as a function of immersion time in electrolyte solutions of tetrathionate, trithionate, the [Au(S2O3)2]3- complex, sulfide and thiosulfate. The generalized two-dimensional correlation spectroscopy was employed to deconvolute broad bands in the SERS spectra. The results show that the polythionates, tetrathionate and trithionate, sulfide, and the [Au(S2O3)2]3- complex decompose to form cyclo-S8, polymeric and monoatomic sulfur at the gold surface. The relative amount of these different forms of sulfur in the film formed at the surface depends on the nature of the electrolyte species. The decomposition of tetrathionate leads predominantly to the formation of cyclo-S8. Comparable amounts of all three forms of sulfur are formed in the solution of the [Au(S2O3)2]3- complex. Monoatomic sulfur is formed predominantly at the gold surface in solutions of trithionate and thiosulfate. In contrast to the previous suggestions, the results of this study demonstrate that polythionates are not present in the passive layer during gold leaching from thiosulfate solutions at a prolonged leaching times.

Case report: intraoperative anaphylactoid reaction and hydroxyethyl starch in balanced electrolyte solution (Hextend).

PubMed

Hall, Brian A; Frigas, Evangelo; Matesic, Damir; Gillett, Michael D; Sprung, Juraj

2006-10-01

To report a first case of probable anaphylactoid reaction to 6% hydroxyethyl starch reconstituted in balanced electrolyte and glucose solution (Hextend). A 22-yr-old man was admitted for a partial nephrectomy. Near the end of the four-hour operation, an infusion of Hextend was initiated. Shortly thereafter, mechanical ventilation became difficult, peak inspiratory pressure increased to 55 cm H2O with audible wheezing over the patient's lungs. Blood pressure suddenly decreased to 68/46 mmHg. Multiple doses of phenylephrine, ephedrine and epinephrine were required to restore the patient's blood pressure. Postoperatively, a diffuse urticarial rash was apparent on his upper torso. The patient recovered uneventfully. His postoperative serum tryptase was 26.3 ng x mL(-1) (reference range, < 11.5 ng x mL(-1)) and the urine N-methyl-histamine was 2448 microg x g(-1) creatinine (reference range, 30-200 microg x g(-1) creatinine). Two months after the event, skin testing was conducted to test for possible allergy to latex, lidocaine, propofol, cisatracurium, succinylcholine, vecuronium, midazolam, fentanyl, ondansetron, neostigmine, and cephazolin, and all were negative. Hextend was also tested, starting with a 1:100,000 dilution and the results were negative. The temporal relationship of severe hypotension, bronchospasm and skin rash within ten minutes from administration of Hextend in this patient suggests an immediate hypersensitivity reaction to hetastarch. The elevated levels of serum tryptase and urinary N-methyl-histamine suggest that this hypersensitivity was mediated from mast cell degranulation. Negative skin testing suggests that the reaction was anaphylactoid.

Electrolytic cell with reference electrode

DOEpatents

Kessie, Robert W.

1989-01-01

A reference electrode device is provided for a high temperature electrolytic cell used to electrolytically recover uranium from spent reactor fuel dissolved in an anode pool, the device having a glass tube to enclose the electrode and electrolyte and serve as a conductive membrane with the cell electrolyte, and an outer metal tube about the glass tube to serve as a shield and basket for any glass sections broken by handling of the tube to prevent their contact with the anode pool, the metal tube having perforations to provide access between the bulk of the cell electrolyte and glass membrane.

Reference electrode for electrolytic cell

DOEpatents

Kessie, R.W.

1988-07-28

A reference electrode device is provided for a high temperature electrolytic cell used to electrolytically recover uranium from spent reactor fuel dissolved in an anode pool, the device having a glass tube to enclose the electrode and electrolyte and serve as a conductive membrane with the cell electrolyte, and an outer metal tube about the glass tube to serve as a shield and basket for any glass sections broken by handling of the tube to prevent their contact with the anode pool, the metal tube having perforations to provide access between the bulk of the cell electrolyte and glass membrane. 4 figs.

Performance of carbon-carbon supercapacitors based on organic, aqueous and ionic liquid electrolytes

NASA Astrophysics Data System (ADS)

Lewandowski, Andrzej; Olejniczak, Angelika; Galinski, Maciej; Stepniak, Izabela

Properties of capacitors working with the same carbon electrodes (activated carbon cloth) and three types of electrolytes: aqueous, organic and ionic liquids were compared. Capacitors filled with ionic liquids worked at a potential difference of 3.5 V, their solutions in AN and PC were charged up to the potential difference of 3 V, classical organic systems to 2.5 V and aqueous to 1 V. Cyclic voltammetry, galvanostatic charging/discharging and impedance spectroscopy were used to characterize these capacitors. The highest specific energy was recorded for the device working with ionic liquids, while the highest power is characteristic for the device filled with aqueous H 2SO 4 electrolyte. Aqueous electrolytes led to energy density an order of magnitude lower in comparison to that characteristic of ionic liquids.

Efficacy and Safety of Combined Oral and Enema Therapy Using Polyethylene Glycol 3350-Electrolyte for Disimpaction in Pediatric Constipation

PubMed Central

Yoo, Taeyeon

2017-01-01

Purpose We evaluated the efficacy and safety of combined oral and enema therapy using polyethylene glycol (PEG) 3350 with electrolyte solution for disimpaction in hospitalized children. Methods We retrospectively studied 28 children having functional constipation who received inpatient treatment between 2008 and 2016. The amount of oral PEG 3350 electrolyte solution administered was 50–70 mL/kg/d (PEG 3350, 3–4.1 g/kg/d), and an enema solution was administered 1–2 times a day as a single dose of 15–25 mL/kg (PEG 3350, 0.975–1.625 g/kg/d). A colon transit time (CTT) test based on the Metcalf protocol was performed in some patients. Results Administration of oral and enema doses of PEG 3350 electrolyte solution showed 2.1±0.3 times and 2.9±0.4 times, respectively. After disimpaction, the frequency of defecation increased from 2.2±0.3 per week to once a day (1.1±0.1 per day). The number of patients who complained of abdominal pain was reduced from 15 (53.6%) to 4 (14.3%). Before hospitalization, nine patients underwent a CTT test, and 5 of 9 patients (55.6%) were classified as belonging to a group showing abnormalities. And in some patients, mild adverse effects were noted. We examined electrolytes and osmolality before and after disimpaction in 16 of 28 patients, and no abnormalities were noted. Conclusion In terms of therapeutic efficacy and safety, combined oral and enema therapy using high-dose PEG 3350 with electrolytes is considered superior to conventional oral monotherapy or combined oral and enema therapy on an outpatient basis. PMID:29302506

Electrochemical noise and impedance of Au electrode/electrolyte interfaces enabling extracellular detection of glioma cell populations

NASA Astrophysics Data System (ADS)

Rocha, Paulo R. F.; Schlett, Paul; Kintzel, Ulrike; Mailänder, Volker; Vandamme, Lode K. J.; Zeck, Gunther; Gomes, Henrique L.; Biscarini, Fabio; de Leeuw, Dago M.

2016-10-01

Microelectrode arrays (MEA) record extracellular local field potentials of cells adhered to the electrodes. A disadvantage is the limited signal-to-noise ratio. The state-of-the-art background noise level is about 10 μVpp. Furthermore, in MEAs low frequency events are filtered out. Here, we quantitatively analyze Au electrode/electrolyte interfaces with impedance spectroscopy and noise measurements. The equivalent circuit is the charge transfer resistance in parallel with a constant phase element that describes the double layer capacitance, in series with a spreading resistance. This equivalent circuit leads to a Maxwell-Wagner relaxation frequency, the value of which is determined as a function of electrode area and molarity of an aqueous KCl electrolyte solution. The electrochemical voltage and current noise is measured as a function of electrode area and frequency and follow unambiguously from the measured impedance. By using large area electrodes the noise floor can be as low as 0.3 μVpp. The resulting high sensitivity is demonstrated by the extracellular detection of C6 glioma cell populations. Their minute electrical activity can be clearly detected at a frequency below about 10 Hz, which shows that the methodology can be used to monitor slow cooperative biological signals in cell populations.

Assessment of Simple Models for Molecular Simulation of Ethylene Carbonate and Propylene Carbonate as Solvents for Electrolyte Solutions.

PubMed

Chaudhari, Mangesh I; Muralidharan, Ajay; Pratt, Lawrence R; Rempe, Susan B

2018-02-12

Progress in understanding liquid ethylene carbonate (EC) and propylene carbonate (PC) on the basis of molecular simulation, emphasizing simple models of interatomic forces, is reviewed. Results on the bulk liquids are examined from the perspective of anticipated applications to materials for electrical energy storage devices. Preliminary results on electrochemical double-layer capacitors based on carbon nanotube forests and on model solid-electrolyte interphase (SEI) layers of lithium ion batteries are considered as examples. The basic results discussed suggest that an empirically parameterized, non-polarizable force field can reproduce experimental structural, thermodynamic, and dielectric properties of EC and PC liquids with acceptable accuracy. More sophisticated force fields might include molecular polarizability and Buckingham-model description of inter-atomic overlap repulsions as extensions to Lennard-Jones models of van der Waals interactions. Simple approaches should be similarly successful also for applications to organic molecular ions in EC/PC solutions, but the important case of Li[Formula: see text] deserves special attention because of the particularly strong interactions of that small ion with neighboring solvent molecules. To treat the Li[Formula: see text] ions in liquid EC/PC solutions, we identify interaction models defined by empirically scaled partial charges for ion-solvent interactions. The empirical adjustments use more basic inputs, electronic structure calculations and ab initio molecular dynamics simulations, and also experimental results on Li[Formula: see text] thermodynamics and transport in EC/PC solutions. Application of such models to the mechanism of Li[Formula: see text] transport in glassy SEI models emphasizes the advantage of long time-scale molecular dynamics studies of these non-equilibrium materials.

Physics Based Modeling and Prognostics of Electrolytic Capacitors

NASA Technical Reports Server (NTRS)

Kulkarni, Chetan; Ceyla, Jose R.; Biswas, Gautam; Goebel, Kai

2012-01-01

This paper proposes first principles based modeling and prognostics approach for electrolytic capacitors. Electrolytic capacitors have become critical components in electronics systems in aeronautics and other domains. Degradations and faults in DC-DC converter unit propagates to the GPS and navigation subsystems and affects the overall solution. Capacitors and MOSFETs are the two major components, which cause degradations and failures in DC-DC converters. This type of capacitors are known for its low reliability and frequent breakdown on critical systems like power supplies of avionics equipment and electrical drivers of electromechanical actuators of control surfaces. Some of the more prevalent fault effects, such as a ripple voltage surge at the power supply output can cause glitches in the GPS position and velocity output, and this, in turn, if not corrected will propagate and distort the navigation solution. In this work, we study the effects of accelerated aging due to thermal stress on different sets of capacitors under different conditions. Our focus is on deriving first principles degradation models for thermal stress conditions. Data collected from simultaneous experiments are used to validate the desired models. Our overall goal is to derive accurate models of capacitor degradation, and use them to predict performance changes in DC-DC converters.

Water, electrolytes, vitamins and trace elements – Guidelines on Parenteral Nutrition, Chapter 7

PubMed Central

Biesalski, H. K.; Bischoff, S. C.; Boehles, H. J.; Muehlhoefer, A.

2009-01-01

A close cooperation between medical teams is necessary when calculating the fluid intake of parenterally fed patients. Fluids supplied parenterally, orally and enterally, other infusions, and additional fluid losses (e.g. diarrhea) must be considered. Targeted diagnostic monitoring (volume status) is required in patients with disturbed water or electrolyte balance. Fluid requirements of adults with normal hydration status is approximately 30–40 ml/kg body weight/d, but fluid needs usually increase during fever. Serum electrolyte concentrations should be determined prior to PN, and patients with normal fluid and electrolyte balance should receive intakes follwing standard recommendations with PN. Additional requirements should usually be administered via separate infusion pumps. Concentrated potassium (1 mval/ml) or 20% NaCl solutions should be infused via a central venous catheter. Electrolyte intake should be adjusted according to the results of regular laboratory analyses. Individual determination of electrolyte intake is required when electrolyte balance is initially altered (e.g. due to chronic diarrhea, recurring vomiting, renal insufficiency etc.). Vitamins and trace elements should be generally substituted in PN, unless there are contraindications. The supplementation of vitamins and trace elements is obligatory after a PN of >1 week. A standard dosage of vitamins and trace elements based on current dietary reference intakes for oral feeding is generally recommended unless certain clinical situations require other intakes. PMID:20049067

Xanthan and κ-carrageenan based alkaline hydrogels as electrolytes for Al/air batteries.

PubMed

Di Palma, T M; Migliardini, F; Caputo, D; Corbo, P

2017-02-10

Xanthan and κ-carrageenan were used to prepare alkaline hydrogels to be used as electrolytes in aluminium air primary batteries. Two pasty gels were obtained starting from xanthan and KOH solutions (1M and 8M), while only the 8M KOH solution permitted the formation of a stable, elastic and gumminess hydrogel with κ-carrageenan. Discharge tests, performed on three Al/air cells assembled with Al anodes, electrolyte gels and Pt based cathodes, evidenced that all hydrogels exhibited appreciable properties of Al ion conductivities, according to the following performance order: xanthan with KOH 1M

Impedance studies of a green blend polymer electrolyte based on PVA and Aloe-vera

NASA Astrophysics Data System (ADS)

Selvalakshmi, S.; Mathavan, T.; Vijaya, N.; Selvasekarapandian, Premalatha, M.; Monisha, S.

2016-05-01

The development of polymer electrolyte materials for energy generating and energy storage devices is a challenge today. A new type of blended green electrolyte based on Poly-vinyl alcohol (PVA) and Aloe-vera has been prepared by solution casting technique. The blending of polymers may lead to the increase in stability due to one polymer portraying itself as a mechanical stiffener and the other as a gelled matrix supported by the other. The prepared blend electrolytes were subjected to Ac impedance studies. It has been found out that the polymer film in which 1 gm of PVA was dissolved in 40 ml of Aloe-vera extract exhibits highest conductivity and its value is 3.08 × 10-4 S cm-1.

Interfacial behavior of polymer electrolytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kerr, John; Kerr, John B.; Han, Yong Bong

2003-06-03

Evidence is presented concerning the effect of surfaces on the segmental motion of PEO-based polymer electrolytes in lithium batteries. For dry systems with no moisture the effect of surfaces of nano-particle fillers is to inhibit the segmental motion and to reduce the lithium ion transport. These effects also occur at the surfaces in composite electrodes that contain considerable quantities of carbon black nano-particles for electronic connection. The problem of reduced polymer mobility is compounded by the generation of salt concentration gradients within the composite electrode. Highly concentrated polymer electrolytes have reduced transport properties due to the increased ionic cross-linking. Combinedmore » with the interfacial interactions this leads to the generation of low mobility electrolyte layers within the electrode and to loss of capacity and power capability. It is shown that even with planar lithium metal electrodes the concentration gradients can significantly impact the interfacial impedance. The interfacial impedance of lithium/PEO-LiTFSI cells varies depending upon the time elapsed since current was turned off after polarization. The behavior is consistent with relaxation of the salt concentration gradients and indicates that a portion of the interfacial impedance usually attributed to the SEI layer is due to concentrated salt solutions next to the electrode surfaces that are very resistive. These resistive layers may undergo actual phase changes in a non-uniform manner and the possible role of the reduced mobility polymer layers in dendrite initiation and growth is also explored. It is concluded that PEO and ethylene oxide-based polymers are less than ideal with respect to this interfacial behavior.« less

Ceramic electrolyte coating methods

DOEpatents

Seabaugh, Matthew M.; Swartz, Scott L.; Dawson, William J.; McCormick, Buddy E.

2004-10-12

Processes for preparing aqueous suspensions of a nanoscale ceramic electrolyte material such as yttrium-stabilized zirconia. The invention also includes a process for preparing an aqueous coating slurry of a nanoscale ceramic electrolyte material. The invention further includes a process for depositing an aqueous spray coating slurry including a ceramic electrolyte material on pre-sintered, partially sintered, and unsintered ceramic substrates and products made by this process.

Gel polymer electrolytes for batteries

DOEpatents

Balsara, Nitash Pervez; Eitouni, Hany Basam; Gur, Ilan; Singh, Mohit; Hudson, William

2014-11-18

Nanostructured gel polymer electrolytes that have both high ionic conductivity and high mechanical strength are disclosed. The electrolytes have at least two domains--one domain contains an ionically-conductive gel polymer and the other domain contains a rigid polymer that provides structure for the electrolyte. The domains are formed by block copolymers. The first block provides a polymer matrix that may or may not be conductive on by itself, but that can soak up a liquid electrolyte, thereby making a gel. An exemplary nanostructured gel polymer electrolyte has an ionic conductivity of at least 1.times.10.sup.-4 S cm.sup.-1 at 25.degree. C.

Electrolyte treatment for aluminum reduction

DOEpatents

Brown, Craig W.; Brooks, Richard J.; Frizzle, Patrick B.; Juric, Drago D.

2002-01-01

A method of treating an electrolyte for use in the electrolytic reduction of alumina to aluminum employing an anode and a cathode, the alumina dissolved in the electrolyte, the treating improving wetting of the cathode with molten aluminum during electrolysis. The method comprises the steps of providing a molten electrolyte comprised of ALF.sub.3 and at least one salt selected from the group consisting of NaF, KF and LiF, and treating the electrolyte by providing therein 0.004 to 0.2 wt. % of a transition metal or transition metal compound for improved wettability of the cathode with molten aluminum during subsequent electrolysis to reduce alumina to aluminum.

Neurologic manifestations of electrolyte disturbances.

PubMed

Riggs, Jack E

2002-02-01

Electrolyte disturbances occur commonly and are associated with a variety of characteristic neurologic manifestations involving both the central and peripheral nervous systems. Electrolyte disturbances are essentially always secondary processes. Effective management requires identification and treatment of the underlying primary disorder. Since neurological symptoms of electrolyte disorders are generally functional rather than structural, the neurologic manifestations of electrolyte disturbances are typically reversible. The neurologic manifestations of serum sodium, potassium, calcium, and magnesium disturbances are reviewed.

Effects of a Carbohydrate-Electrolyte Drink on Specific Soccer Tests and Performance

PubMed Central

Ostojic, Sergej M.; Mazic, Sanja

2002-01-01

The aim of this study was to examine the effects of a carbohydrate-electrolyte drink on specific soccer tests and performance. Twenty-two professional male soccer players volunteered to participate in the study. The players were allocated to two assigned trials ingesting carbohydrate-electrolyte drink (7% carbohydrates, sodium 24 mmol.l-1, chloride 12 mmol.l-1, potassium 3 mmol.l-1) or placebo during a 90 min on-field soccer match. The trials were matched for subjects’ age, weight, height and maximal oxygen uptake. Immediately after the match, players completed four soccer-specific skill tests. Blood glucose concentration [mean (SD)] was higher at the end of the match-play in the carbohydrate-electrolyte trial than in the placebo trial (4.4 (0.3) vs. 4.0 (0.3) mmol.l-1, P < 0.05). Subjects in the carbohydrate-electrolyte trial finished the specific dribble test faster in comparison with subjects in the placebo trial (12.9 (0.4) vs. 13.6 (0.5) s, P < 0.05). Ratings of the precision test were higher in the carbohydrate-electrolyte trial as compared to the placebo trial (17.2 (4.8) vs. 15.1 (5.2), P < 0.05) but there were no differences in coordination test and power test results between trials. The main finding of the present study indicates that supplementation with carbohydrate-electrolyte solution improved soccer-specific skill performance and recovery after an on-field soccer match compared with ingestion of placebo. This suggests that soccer players should consume carbohydrate-electrolyte fluid throughout a game to help prevent deterioration in specific skill performance. PMID:24688270

Bubble coalescence suppression driven carbon monoxide (CO)-water mass transfer increase by electrolyte addition in a hollow fiber membrane bioreactor (HFMBR) for microbial CO conversion to ethanol.

PubMed

Jang, Nulee; Yasin, Muhammad; Kang, Hyunsoo; Lee, Yeubin; Park, Gwon Woo; Park, Shinyoung; Chang, In Seop

2018-05-04

This study investigated the effects of electrolytes (CaCl 2 , K 2 HPO 4 , MgSO 4 , NaCl, and NH 4 Cl) on CO mass transfer and ethanol production in a HFMBR. The hollow fiber membranes (HFM) were found to generate tiny gas bubbles; the bubble coalescence was significantly suppressed in electrolyte solution. The volumetric gas-liquid mass transfer coefficients (k L a) increased up to 414% compared to the control. Saturated CO (C ∗ ) decreased as electrolyte concentrations increased. Overall, the maximum mass transfer rate (R max ) in electrolyte solution ranged from 106% to 339% of the value obtained in water. The electrolyte toxicity on cell growth was tested using Clostridium autoethanogenum. Most electrolytes, except for MgSO 4 , inhibited cell growth. The HFMBR operation using a medium containing 1% MgSO 4 achieved 119% ethanol production compared to that without electrolytes. Finally, a kinetic simulation using the parameters got from the 1% MgSO 4 medium predicted a higher ethanol production compared to the control. Copyright © 2018 Elsevier Ltd. All rights reserved.

Electrolytic conductivity at 0.5 S m-1 and 5 mS m-1

NASA Astrophysics Data System (ADS)

Seitz, S.; Sander, B.; Snedden, A.; DeLeeBeeck, L.; Canaza, G. T.; Asakai, T.; Maksimov, I.; Song, X.; Wang, H.; Kozlowski, W.; Dumanska, J.; Jakusovszky, B.; Szilágyi, Z. N.; Gavrilkin, V.; Stennik, O.; Ovchinnikov, Y.; Gonzaga, F. B.; da Cruz Cunha, K.; Ferraz, S. F.; Hanková, Z.; Máriássy, M.; Vicarova, M.; Vospelova, A.; Ortiz-Aparicio, J. L.; Lara-Manzano, J. V.; Uribe-Godínez, J.; Stoica, D.; Fisicaro, P.; Suvorov, V. I.; Konopelko, L. A.; Smirnov, A. M.; Amaya, R. C.; Quezada, H. T.

2017-01-01

Key Comparison CCQM-K36.2016 was a follow-up comparison for K36 and provided updated support for the corresponding calibration and measurement capability (CMC) entries in the BIPM CMC database. It aimed to demonstrate the capabilities of the participating NMIs to measure electrolytic conductivity of aqueous electrolyte solutions in the conductivity range 0.15 S m-1 to 1.5 S m-1 and in the conductivity range 1.5 mS m-1 to 15 mS m-1. To this end electrolytic conductivity of a potassium chloride solution (nominal conductivity 0.5 S m-1) and of a HCl solution (nominal conductivity 5 mS m-1) had to be measured. 17 NMIs participated in the comparison. The key comparison reference value (KCRV) of the KCl solution was (0.50999 +/-0.00032) S m-1 and the KCRV of the HCl solution was (4.9877 +/-0.012) mS m-1. Both values were estimated from the medians of the results considered eligible for KCRV calculation. They were given with their expanded uncertainties (95% coverage). The majority of the 0.5 S m-1 results were consistent with the KCRV. Two institutes showed a small inconsistency, one outlier was observed. The conductivity of the HCl solution showed a small, but steady linear drift of 0.00006843 mS m-1 per day during the measurement period and was corrected for KCRV calculation. Some institutes reported unstable measurement conditions for this solution. The results of seven participants have been inconsistent with the KCRV. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Electrolyte paste for molten carbonate fuel cells

DOEpatents

Bregoli, Lawrance J.; Pearson, Mark L.

1995-01-01

The electrolyte matrix and electrolyte reservoir plates in a molten carbonate fuel cell power plant stack are filled with electrolyte by applying a paste of dry electrolyte powder entrained in a dissipatable carrier to the reactant flow channels in the current collector plate. The stack plates are preformed and solidified to final operating condition so that they are self sustaining and can be disposed one atop the other to form the power plant stack. Packing the reactant flow channels with the electrolyte paste allows the use of thinner electrode plates, particularly on the anode side of the cells. The use of the packed electrolyte paste provides sufficient electrolyte to fill the matrix and to entrain excess electrolyte in the electrode plates, which also serve as excess electrolyte reservoirs. When the stack is heated up to operating temperatures, the electrolyte in the paste melts, the carrier vaporizes, or chemically decomposes, and the melted electrolyte is absorbed into the matrix and electrode plates.

Preparation and electrochemical characterization of gel polymer electrolyte based on electrospun polyacrylonitrile nonwoven membranes for lithium batteries

NASA Astrophysics Data System (ADS)

Raghavan, Prasanth; Manuel, James; Zhao, Xiaohui; Kim, Dul-Sun; Ahn, Jou-Hyeon; Nah, Changwoon

Electrospun membranes of polyacrylonitrile are prepared, and the electrospinning parameters are optimized to get fibrous membranes with uniform bead-free morphology. The polymer solution of 16 wt.% in N, N-dimethylformamide at an applied voltage of 20 kV results in the nanofibrous membrane with average fiber diameter of 350 nm and narrow fiber diameter distribution. Gel polymer electrolytes are prepared by activating the nonwoven membranes with different liquid electrolytes. The nanometer level fiber diameter and fully interconnected pore structure of the host polymer membranes facilitate easy penetration of the liquid electrolyte. The gel polymer electrolytes show high electrolyte uptake (>390%) and high ionic conductivity (>2 × 10 -3 S cm -1). The cell fabricated with the gel polymer electrolytes shows good interfacial stability and oxidation stability >4.7 V. Prototype coin cells with gel polymer electrolytes based on a membrane activated with 1 M LiPF 6 in ethylene carbonate/dimethyl carbonate or propylene carbonate are evaluated for discharge capacity and cycle property in Li/LiFePO 4 cells at room temperature. The cells show remarkably good cycle performance with high initial discharge properties and low capacity fade under continuous cycling.

Batteries using molten salt electrolyte

DOEpatents

Guidotti, Ronald A.

2003-04-08

An electrolyte system suitable for a molten salt electrolyte battery is described where the electrolyte system is a molten nitrate compound, an organic compound containing dissolved lithium salts, or a 1-ethyl-3-methlyimidazolium salt with a melting temperature between approximately room temperature and approximately 250.degree. C. With a compatible anode and cathode, the electrolyte system is utilized in a battery as a power source suitable for oil/gas borehole applications and in heat sensors.

Stabilization of Silicon Carbide (SiC) micro- and nanoparticle dispersions in the presence of concentrated electrolyte.

PubMed

Vilinska, Annamaria; Ponnurangam, Sathish; Chernyshova, Irina; Somasundaran, Ponisseril; Eroglu, Damla; Martinez, Jose; West, Alan C

2014-06-01

Achieving a stable and robust dispersion of ultrafine particles in concentrated electrolytes is challenging due to the shielding of electrostatic repulsion. Stable dispersion of ultrafine particles in concentrated electrolytes is critical for several applications, including electro-codeposition of ceramic particles in protective metal coatings. We achieved the steric stabilization of SiC micro- and nano-particles in highly concentrated electroplating Watts solutions using their controlled coating with linear and branched polyethyleneimines (PEI) as dispersants. Branched polyethyleneimine of 60,000 MW effectively disperses both microparticles and nanoparticles at a concentration of 1000 ppm. However, lower polymer dosages and smaller polymers fail to disperse, presumably due to insufficient coverage and bridging flocculation. Dispersion stability correlates well with the adsorption density of PEI on microparticles. We discuss the results in the framework of DLVO theory and suggest possible dispersion mechanisms. However, though the dispersion is enhanced with extended adsorption time, the residual PEI in solution adversely affects electroplating. We overcome this drawback by precoating the particles with the polymer and resuspending them in Watts solution. With this novel approach, we obtained robust dispersions. These results offer new possibilities to control dispersion at high electrolyte concentration, as well as bring new insights into the dispersion phenomenon. Copyright © 2014 Elsevier Inc. All rights reserved.

Jumping liquid metal droplet in electrolyte triggered by solid metal particles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang, Jianbo; University of Chinese Academy of Sciences, Beijing 100049; Wang, Junjie

2016-05-30

We report the electron discharge effect due to point contact between liquid metal and solid metal particles in electrolyte. Adding nickel particles induces drastic hydrogen generating and intermittent jumping of a sub-millimeter EGaIn droplet in NaOH solution. Observations from different orientations disclose that such jumping behavior is triggered by pressurized bubbles under the assistance of interfacial interactions. Hydrogen evolution around particles provides clear evidence that such electric instability originates from the varied electric potential and morphology between the two metallic materials. The point-contact-induced charge concentration significantly enhances the near-surface electric field intensity at the particle tips and thus causes electricmore » breakdown of the electrolyte.« less

Ultrafast fluxional exchange dynamics in electrolyte solvation sheath of lithium ion battery

NASA Astrophysics Data System (ADS)

Lee, Kyung-Koo; Park, Kwanghee; Lee, Hochan; Noh, Yohan; Kossowska, Dorota; Kwak, Kyungwon; Cho, Minhaeng

2017-03-01

Lithium cation is the charge carrier in lithium-ion battery. Electrolyte solution in lithium-ion battery is usually based on mixed solvents consisting of polar carbonates with different aliphatic chains. Despite various experimental evidences indicating that lithium ion forms a rigid and stable solvation sheath through electrostatic interactions with polar carbonates, both the lithium solvation structure and more importantly fluctuation dynamics and functional role of carbonate solvent molecules have not been fully elucidated yet with femtosecond vibrational spectroscopic methods. Here we investigate the ultrafast carbonate solvent exchange dynamics around lithium ions in electrolyte solutions with coherent two-dimensional infrared spectroscopy and find that the time constants of the formation and dissociation of lithium-ion...carbonate complex in solvation sheaths are on a picosecond timescale. We anticipate that such ultrafast microscopic fluxional processes in lithium-solvent complexes could provide an important clue to understanding macroscopic mobility of lithium cation in lithium-ion battery on a molecular level.

Ultrafast fluxional exchange dynamics in electrolyte solvation sheath of lithium ion battery

PubMed Central

Lee, Kyung-Koo; Park, Kwanghee; Lee, Hochan; Noh, Yohan; Kossowska, Dorota; Kwak, Kyungwon; Cho, Minhaeng

2017-01-01

Lithium cation is the charge carrier in lithium-ion battery. Electrolyte solution in lithium-ion battery is usually based on mixed solvents consisting of polar carbonates with different aliphatic chains. Despite various experimental evidences indicating that lithium ion forms a rigid and stable solvation sheath through electrostatic interactions with polar carbonates, both the lithium solvation structure and more importantly fluctuation dynamics and functional role of carbonate solvent molecules have not been fully elucidated yet with femtosecond vibrational spectroscopic methods. Here we investigate the ultrafast carbonate solvent exchange dynamics around lithium ions in electrolyte solutions with coherent two-dimensional infrared spectroscopy and find that the time constants of the formation and dissociation of lithium-ion···carbonate complex in solvation sheaths are on a picosecond timescale. We anticipate that such ultrafast microscopic fluxional processes in lithium-solvent complexes could provide an important clue to understanding macroscopic mobility of lithium cation in lithium-ion battery on a molecular level. PMID:28272396

Ultrafast fluxional exchange dynamics in electrolyte solvation sheath of lithium ion battery.

PubMed

Lee, Kyung-Koo; Park, Kwanghee; Lee, Hochan; Noh, Yohan; Kossowska, Dorota; Kwak, Kyungwon; Cho, Minhaeng

2017-03-08

Lithium cation is the charge carrier in lithium-ion battery. Electrolyte solution in lithium-ion battery is usually based on mixed solvents consisting of polar carbonates with different aliphatic chains. Despite various experimental evidences indicating that lithium ion forms a rigid and stable solvation sheath through electrostatic interactions with polar carbonates, both the lithium solvation structure and more importantly fluctuation dynamics and functional role of carbonate solvent molecules have not been fully elucidated yet with femtosecond vibrational spectroscopic methods. Here we investigate the ultrafast carbonate solvent exchange dynamics around lithium ions in electrolyte solutions with coherent two-dimensional infrared spectroscopy and find that the time constants of the formation and dissociation of lithium-ion···carbonate complex in solvation sheaths are on a picosecond timescale. We anticipate that such ultrafast microscopic fluxional processes in lithium-solvent complexes could provide an important clue to understanding macroscopic mobility of lithium cation in lithium-ion battery on a molecular level.

Effects of CH3OH Addition on Plasma Electrolytic Oxidation of AZ31 Magnesium Alloys

NASA Astrophysics Data System (ADS)

He, Yongyi; Chen, Li; Yan, Zongcheng; Zhang, Yalei

2015-09-01

Plasma electrolytic oxidation (PEO) films on AZ31 magnesium alloys were prepared in alkaline silicate electrolytes (base electrolyte) with the addition of different volume concentrations of CH3OH, which was used to adjust the thickness of the vapor sheath. The compositions, morphologies, and thicknesses of ceramic layers formed with different CH3OH concentrations were determined via X-ray diffraction (XRD), energy-dispersive spectroscopy (EDS), and scanning electron microscopy (SEM). Corrosion behavior of the oxide films was evaluated in 3.5 wt.% NaCl solution using potentiodynamic polarization tests. PEO coatings mainly comprised Mg, MgO, and Mg2SiO4. The addition of CH3OH in base electrolytes affected the thickness, pores diameter, and Mg2SiO4 content in the films. The films formed in the electrolyte containing 12% CH3OH exhibited the highest thickness. The coatings formed in the electrolyte containing different concentrations of CH3OH exhibited similar corrosion resistance. The energy consumption of PEO markedly decreased upon the addition of CH3OH to the electrolytes. The result is helpful for energy saving in the PEO process. supported by National Natural Science Foundation of China (No. 21376088), the Project of Production, Education and Research, Guangdong Province and Ministry of Education (Nos. 2012B09100063, 2012A090300015), and Guangzhou Science and Technology Plan Projects of China (No. 2014Y2-00042)

Establishing reference intervals for electrolytes in newborns and infants using direct ISE analyzer

PubMed Central

2013-01-01

Background To generate clinically applicable reference intervals (RIs) for commonly requested electrolytes in Ethiopian newborns and infants that can help in early detection, close monitoring and correction of electrolyte abnormalities. Cord blood (from newborns, n = 60) and venous blood samples (from infants, n = 57) were collected and analyzed using direct ISE analyzer, AVL (9181). MedCalc® software was applied to determine the robust upper and lower end points covering 95% of the reference values of each electrolyte with respective 90% CIs. Findings This is an extension report of our recent study; and hence is resulted from the same data source. The level of Na+ and K+ showed difference in newborns and infants even though combined RIs were suggested by the Haris and Boyd rule as 126–143 mmol/l and 4.0-7.9 mmol/l respectively. However, Cl- values failed to show such a difference and thus a combined RI was determined to be 100–111 mmol/l. Almost all maternal, neonatal and infantile factors were not able to affect the values of the electrolytes. Conclusion Combined RIs are suggested for the interpretation of electrolyte values in newborns and infants without taking the effect of maternal, neonatal and infantile factors into account. Since the RIs were different from previously reported values, it will be appropriate to apply such RIs for the interpretation of electrolyte values in Ethiopian pediatric population. PMID:23688032

Synthesis and Characterization of Cellulose-Based Hydrogels to Be Used as Gel Electrolytes

PubMed Central

Navarra, Maria Assunta; Dal Bosco, Chiara; Serra Moreno, Judith; Vitucci, Francesco Maria; Paolone, Annalisa; Panero, Stefania

2015-01-01

Cellulose-based hydrogels, obtained by tuned, low-cost synthetic routes, are proposed as convenient gel electrolyte membranes. Hydrogels have been prepared from different types of cellulose by optimized solubilization and crosslinking steps. The obtained gel membranes have been characterized by infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and mechanical tests in order to investigate the crosslinking occurrence and modifications of cellulose resulting from the synthetic process, morphology of the hydrogels, their thermal stability, and viscoelastic-extensional properties, respectively. Hydrogels liquid uptake capability and ionic conductivity, derived from absorption of aqueous electrolytic solutions, have been evaluated, to assess the successful applicability of the proposed membranes as gel electrolytes for electrochemical devices. To this purpose, the redox behavior of electroactive species entrapped into the hydrogels has been investigated by cyclic voltammetry tests, revealing very high reversibility and ion diffusivity. PMID:26633528

Incorporating allylated lignin-derivatives in thiol-ene gel-polymer electrolytes.

PubMed

Baroncini, Elyse A; Stanzione, Joseph F

2018-07-01

Growing environmental and economic concerns as well as the uncertainty that accompanies finite petrochemical resources contributes to the increase in research and development of bio-based, renewable polymers. Concurrently, industrial and consumer demand for smaller, safer, and more flexible technologies motivates a global research effort to improve electrolytic polymer separators in lithium-ion batteries. To incorporate the aromatic structural advantages of lignin, a highly abundant and renewable resource, into gel-polymer electrolytes, lignin-derived molecules, vanillyl alcohol and gastrodigenin are functionalized and UV-polymerized with multi-functional thiol monomers. The resulting thin, flexible, polymer films possess glass transition temperatures ranging from -42.1°C to 0.3°C and storage moduli at 25°C ranging from 1.90MPa to 10.08MPa. The crosslinked polymer films swollen with electrolyte solution impart conductivities in the range of 7.04×10 -7 to 102.73×10 -7 Scm -1 . Thiol molecular weight has the most impact on the thermo-mechanical properties of the resulting films while polymer crosslink density has the largest effect on conductivity. The conducting abilities of the bio-based gel-polymer electrolytes in this study prove the viability of lignin-derived feedstock for use in lithium-ion battery applications and reveal structurally and thermally desirable traits for future work. Copyright © 2018 Elsevier B.V. All rights reserved.

Electrochemical insertion of magnesium ions into V2O5 from aprotic electrolytes with varied water content.

PubMed

Yu, Long; Zhang, Xiaogang

2004-10-01

The electrochemical performance of V2O5 has been studied in propylene carbonate (PC)-containing magnesium perchlorate [Mg(ClO4)2] electrolytes in view of their application as positive electrode in the rechargeable magnesium batteries. V2O5 exhibited good properties in hosting magnesium ions and its electrochemical performance depended on the amount of H2O in the electrolytes. The highest first discharge specific capacities of V2O5 electrode was up to 158.6 mAh/g in 1 mol dm(-3) Mg(ClO4)2 + 1.79 mol dm(-3) H2O/PC electrolytes. Electrochemical impedance spectroscopy (EIS) and charging-discharging tests showed that a reasonable amount of H2O in the electrolyte solution facilitated the electrochemical performance of V2O5 electrodes.

Studies on the effect of dispersoid(ZrO2) in PVdF-co-HFP based gel polymer electrolytes

NASA Astrophysics Data System (ADS)

Sivakumar, M.; Subadevi, R.; Muthupradeepa, R.

2013-06-01

Gel polymer electrolytes containing poly(vinylidenefluoride-co-hexafluoropropylene) (P(VdF-co-HFP)) / Lithium bis(trifluoromethane sulfon)imide (LiTFSI) / mixture of ethylene carbonate and propylene carbonate (EC+PC) with different concendration of ZrO2 has been prepared using the solution casting technique. The conductivity of the prepared electrolyte sample has been determined by AC impedance technique in the range 303-353K. The temperature dependent ionic conductivity plot seems to obey VTF relation. The maximum ionic conductivity value of 4.46 × 10-3S/cm has been obtained for PVdF-co-HFP(32%) - LiTFSI(8%) - EC+PC (60%) + ZrO2(6wt%) based polymer electrolyte. The surface morphology of the prepared electrolyte sample has been studied using SEM.

Nuclear magnetic resonance studies of the solvation structures of a high-performance nonaqueous redox flow electrolyte

NASA Astrophysics Data System (ADS)

Deng, Xuchu; Hu, Mary; Wei, Xiaoliang; Wang, Wei; Mueller, Karl T.; Chen, Zhong; Hu, Jian Zhi

2016-03-01

Understanding the solvation structures of electrolytes is important for developing nonaqueous redox flow batteries that hold considerable potential for future large scale energy storage systems. The utilization of an emerging ionic-derivatived ferrocene compound, ferrocenylmethyl dimethyl ethyl ammonium bis(trifluoromethanesulfonyl)imide (Fc1N112-TFSI), has recently overcome the issue of solubility in the supporting electrolyte. In this work, 13C, 1H and 17O NMR investigations were carried out using electrolyte solutions consisting of Fc1N112-TFSI as the solute and the mixed alkyl carbonate as the solvent. It was observed that the spectra of 13C experience changes of chemical shifts while those of 17O undergo linewidth broadening, indicating interactions between solute and solvent molecules. Quantum chemistry calculations of both molecular structures and chemical shifts (13C, 1H and 17O) are performed for interpreting experimental results and for understanding the detailed solvation structures. The results indicate that Fc1N112-TFSI is dissociated at varying degrees in mixed solvent depending on concentrations. At dilute solute concentrations, most Fc1N112+ and TFSI- are fully disassociated with their own solvation shells formed by solvent molecules. At saturated concentration, Fc1N112+-TFSI- contact ion pairs are formed and the solvent molecules are preferentially interacting with the Fc rings rather than interacting with the ionic pendant arm of Fc1N112-TFSI.

Influence of anionic substitution on the electrolyte electroreflectance study of band edge transitions in single crystal Cu2ZnSn(SxSe1-x)4 solid solutions

NASA Astrophysics Data System (ADS)

Levcenco, S.; Dumcenco, D.; Wang, Y. P.; Huang, Y. S.; Ho, C. H.; Arushanov, E.; Tezlevan, V.; Tiong, K. K.

2012-06-01

Single crystals of Cu2ZnSn(SxSe1-x)4 (CZTSSe) solid solutions were grown by chemical vapor transport technique using iodine trichloride as a transport agent. As confirmed by X-ray investigations, the as-grown CZTSSe solid solutions are single phase and crystallized in kesterite structure. The lattice parameters of CZTSSe were determined and the S contents of the obtained crystals were estimated by Vegard's law. The composition dependent band gaps of CZTSSe solid solutions were studied by electrolyte electroreflectance (EER) measurements at room temperature. From a detailed lineshape fit of the EER spectra, the band gaps of CZTSSe were determined accurately and were found to decrease almost linearly with the increase of Se content, which agreed well with the recent theoretical first-principle calculations by S. Chen, A. Walsh, J.H. Yang, X.G. Gong, L. Sun, P. X. Yang, J.H. Chu, S.H. Wei, Phys. Rev. B 83 (2011) 125201 (5pp).

Balanced Fluid Versus Saline-Based Fluid in Post-operative Severe Traumatic Brain Injury Patients: Acid-Base and Electrolytes Assessment

PubMed Central

Hassan, Mohamad Hasyizan; Hassan, Wan Mohd Nazaruddin Wan; Zaini, Rhendra Hardy Mohd; Shukeri, Wan Fadzlina Wan Muhd; Abidin, Huda Zainal; Eu, Chong Soon

2017-01-01

Background Normal saline (NS) is a common fluid of choice in neurosurgery and neuro-intensive care unit (ICU), but it does not contain other electrolytes and has the potential to cause hyperchloremic metabolic acidosis with prolonged infusion. These problems may be reduced with the availability of balanced fluid (BF), which becomes a more physiological isotonic solution with the presence of complete electrolyte content. This study aimed to compare the changes in electrolytes and acid–base between NS and BF (Sterofundin® ISO) therapy for post-operative severe traumatic brain injury (TBI) patients in neuro-ICU. Methods Sixty-six severe TBI patients who required emergency craniotomy or craniectomy and were planned for post-operative ventilation were randomised into NS (n = 33) and BF therapy groups (n = 33). The calculation of maintenance fluid given was based on the Holliday-Segar method. The electrolytes and acid–base parameters were assessed at an 8 h interval for 24 h. The data were analysed using repeated measures ANOVA. Results The NS group showed a significant lower base excess (−3.20 versus −1.35, P = 0.049), lower bicarbonate level (22.03 versus 23.48 mmol/L, P = 0.031), and more hyperchloremia (115.12 versus 111.74 mmol/L, P < 0.001) and hypokalemia (3.36 versus 3.70 mmol/L, P < 0.001) than the BF group at 24 h of therapy. The BF group showed a significantly higher level of calcium (1.97 versus 1.79 mmol/L, P = 0.003) and magnesium (0.94 versus 0.80 mmol/L, P < 0.001) than the NS group at 24 h of fluid therapy. No significant differences were found in pH, pCO2, lactate, and sodium level. Conclusion BF therapy showed better effects in maintaining higher electrolyte parameters and reducing the trend toward hyperchloremic metabolic acidosis than the NS therapy during prolonged fluid therapy for postoperative TBI patients. PMID:29386975

Enhanced photoelectric performance in self-powered UV detectors based on ZnO nanowires with plasmonic Au nanoparticles scattered electrolyte

NASA Astrophysics Data System (ADS)

Zeng, Yiyu; Ye, Zhizhen; Lu, Bin; Dai, Wei; Pan, Xinhua

2016-04-01

Vertically aligned ZnO nanowires (NWs) were grown on a fluorine-doped tin-oxide-coated glass substrate by a hydrothermal method. Au nanoparticles were well dispersed in the mixed solution of ethanol and deionized water. A simple self-powered ultraviolet detector based on solid-liquid heterojunction was fabricated, utilizing ZnO NWs as active photoanode and such prepared mixed solution as electrolyte. The introduction of Au nanoparticles results in considerable improvements in the responsivity and sensitivity of the device compared with the one using deionized water as electrolyte, which is attributed to the enhanced light harvesting by Au nanoparticles.

Electrolyte additive for improved battery performance

DOEpatents

Bellows, Richard J.; Kantner, Edward

1989-04-04

In one embodiment of the present invention, there is provided an electrochemical cell having a metal bromine couple. The cell includes an electrode structure on which to deposit the metal of the couple and a counterelectrode at which to generate bromine. A microporous membrane separates the electrode and counterelectrode. Importantly, the aqueous electrolyte comprises an aqueous metal bromide solution containing a water soluble bromine complexing agent capable of forming a water immiscible complex with bromine and an additive capable of decreasing the wettability of the microporous separators employed in such cells by such water immiscible bromine complexes.

Effect of cycling on the lithium/electrolyte interface in organic electrolytes

NASA Technical Reports Server (NTRS)

Surampudi, S.; Shen, D. H.; Huang, C.-K.; Narayanan, S. R.; Attia, A.; Halpert, G.; Peled, E.

1993-01-01

Nondestructive methods such as ac impedance spectroscopy and microcalorimetry are used to study the effect of cell cycling on the lithium/electrolyte interface. The reactivity of both uncycled and cycled lithium towards various electrolytes is examined by measuring the heat evolved from the cells under open-circuit conditions at 25 C by microcalorimetry. Cycled cells at the end of charge/discharge exhibited considerably higher heat output compared with the uncycled cells. After 30 d of storage, the heat output of the cycled cells is similar to that of the uncycled cells. The cell internal resistance increases with cycling, and this is attributed to the degradation of the electrolyte with cycling.

Non-aqueous electrolytes for electrochemical cells

DOEpatents

Zhang, Zhengcheng; Dong, Jian; Amine, Khalil

2016-06-14

An electrolyte electrochemical device includes an anodic material and an electrolyte, the electrolyte including an organosilicon solvent, a salt, and a hybrid additiving having a first and a second compound, the hybrid additive configured to form a solid electrolyte interphase film on the anodic material upon application of a potential to the electrochemical device.

Effects of an electrolyte additive on hydration and drinking behavior during wildfire suppression.

PubMed

Cuddy, John S; Ham, Julie A; Harger, Stephanie G; Slivka, Dustin R; Ruby, Brent C

2008-01-01

The purpose of this study was to compare the effects of a water + electrolyte solution versus plain water on changes in drinking behaviors, hydration status, and body temperatures during wildfire suppression. Eight participants consumed plain water, and eight participants consumed water plus an electrolyte additive during 15 hours of wildfire suppression. Participants wore a specially outfitted backpack hydration system equipped with a digital flow meter system affixed inline to measure drinking characteristics (drinking frequency and volume). Body weight and urine-specific gravity were collected pre- and postshift. Ambient, core, and skin temperatures were measured continuously using a wireless system. Work output was monitored using accelerometry. There were no differences between groups for body weight, drinking frequency, temperature data, activity, or urine-specific gravity (1.019 +/- 0.007 to 1.023 +/- 0.010 vs. 1.019 +/- 0.005 to 1.024 +/- 0.009 for water and water + electrolyte groups pre- and postshift, respectively; P < .05). There was a main effect for time for body weight, demonstrating an overall decrease (78.1 +/- 13.3 and 77.3 +/- 13.3 kg pre- and postshift, respectively; P < .05) across the work shift. The water group consumed more total fluid (main effect for treatment) than the water + electrolyte group (504 +/- 472 vs. 285 +/- 279 mL.h(-1) for the water and water + electrolyte groups, respectively; P < .05). The addition of an electrolyte mixture to plain water decreased the overall fluid consumption of the water + electrolyte group by 220 mL.h(-1) (3.3 L.d(-1)). Supplementing water with electrolytes can reduce the amount of fluid necessary to consume and transport during extended activity. This can minimize carrying excessive weight, possibly reducing fatigue during extended exercise.

Double-membrane triple-electrolyte redox flow battery design

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yushan, Yan; Gu, Shuang; Gong, Ke

A redox flow battery is provided having a double-membrane (one cation exchange membrane and one anion exchange membrane), triple-electrolyte (one electrolyte in contact with the negative electrode, one electrolyte in contact with the positive electrode, and one electrolyte positioned between and in contact with the two membranes). The cation exchange membrane is used to separate the negative or positive electrolyte and the middle electrolyte, and the anion exchange membrane is used to separate the middle electrolyte and the positive or negative electrolyte. This design physically isolates, but ionically connects, the negative electrolyte and positive electrolyte. The physical isolation offers greatmore » freedom in choosing redox pairs in the negative electrolyte and positive electrolyte, making high voltage of redox flow batteries possible. The ionic conduction drastically reduces the overall ionic crossover between negative electrolyte and positive one, leading to high columbic efficiency.« less

Fluorinated Electrolytes for Li-S Battery: Suppressing the Self-Discharge with an Electrolyte Containing Fluoroether Solvent

DOE Office of Scientific and Technical Information (OSTI.GOV)

Azimi, N.; Xue, Z.; Rago, N. D.

The fluorinated electrolyte containing a fluoroether 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE) was investigated as a new electrolyte for lithium-sulfur (Li-S) batteries. The low solubility of lithium polysulfides (LiPS) in the fluorinated electrolyte reduced the parasitic reactions with Li anode and mitigated the self-discharge by limiting their diffusion from the cathode to the anode. The use of fluorinated ether as a co-solvent and LiNO3 as an additive in the electrolyte shows synergetic effect in suppressing the self-discharge of Li-S battery due to the formation of the solid electrolyte interphase (SEI) on both sulfur cathode and the lithium anode. The Li-S cell with themore » fluorinated electrolyte showed prolonged shelf life at fully charged state.« less

Artificially-built solid electrolyte interphase via surface-bonded vinylene carbonate derivative on graphite by molecular layer deposition

NASA Astrophysics Data System (ADS)

Chae, Seulki; Lee, Jeong Beom; Lee, Jae Gil; Lee, Tae-jin; Soon, Jiyong; Ryu, Ji Heon; Lee, Jin Seok; Oh, Seung M.

2017-12-01

Vinylene carbonate (VC) is attached in a ring-opened form on a graphite surface by molecular layer deposition (MLD) method, and its role as a solid electrolyte interphase (SEI) former is studied. When VC is added into the electrolyte solution of a graphite/LiNi0.5Mn1.5O4 (LNMO) full-cell, it is reductively decomposed to form an effective SEI on the graphite electrode. However, VC in the electrolyte solution has serious adverse effects due to its poor stability against electrochemical oxidation on the LNMO positive electrode. A excessive acid generation as a result of VC oxidation is observed, causing metal dissolution from the LNMO electrode. The dissolved metal ions are plated on the graphite electrode to destroy the SEI layer, eventually causing serious capacity fading and poor Coulombic efficiency. The VC derivative on the graphite surface also forms an effective SEI layer on the graphite negative electrode via reductive decomposition. The detrimental effects on the LNMO positive electrode, however, can be avoided because the bonded VC derivative on the graphite surface cannot move to the LNMO electrode. Consequently, the graphite/LNMO full-cell fabricated with the VC-attached graphite outperforms the cells without VC or with VC in the electrolyte, in terms of Coulombic efficiency and capacity retention.

Zirconia based ceramic coating on a metal with plasma electrolytic oxidation

NASA Astrophysics Data System (ADS)

Akatsu, T.; Kato, T.; Shinoda, Y.; Wakai, F.

2011-10-01

We challenge to fabricate a thermal barrier coating (TBC) made of ZrO2 based ceramics on a Ni based single crystal superalloy with plasma electrolytic oxidation (PEO) by incorporating metal species from electrolyte into the coating. The PEO process is carried out on the superalloy galvanized with aluminium for 15min in Na4O7P4 solution for an oxygen barrier coating (OBC) and is followed by PEO in K2[Zr(CO3)2(OH)2] solution for TBC. We obtained the following results; (1) Monoclinic-, tetragonal-, cubic-ZrO2 crystals were detected in TBC. (2) High porosity with large pores was observed near the interface between OBC and TBC. The fine grain structure with a grain size of about 300nm was typically observed. (3) The adhesion strength between PEO coatings and substrate was evaluated to be 26.8±6.6MPa. At the adhesion strength test, PEO coatings fractured around the interface between OBC and TBC. The effect of coating structure on adhesion strength is explained through the change in spark discharge during PEO process.

Ionogel Electrolytes through Sol-Gel Processing

NASA Astrophysics Data System (ADS)

Horowitz, Ariel I.

Electrical energy needs have intensified due to the ubiquity of personal electronics, the decarbonization of energy services through electrification, and the use of intermittent renewable energy sources. Despite developments in mechanical and thermal methods, electrochemical technologies are the most convenient and effective means of storing electrical energy. These technologies include both electrochemical cells, commonly called batteries, and electrochemical double-layer capacitors, or "supercapacitors", which store energy electrostatically. Both device types require an ion-conducting electrolyte. Current devices use solutions of complex salts in organic solvents, leading to both toxicity and flammability concerns. These drawbacks can be avoided by replacing conventional electrolytes with room-temperature molten salts, known as ionic liquids (ILs). ILs are non-volatile, non-flammable, and offer high conductivity and good electrochemical stability. Device mass can be reduced by combining ILs with a solid scaffold material to form an "ionogel," further improving performance metrics. In this work, sol-gel chemistry is explored as a means of forming ionogel electrolytes. Sol-gel chemistry is a solution-based, industrially-relevant, well-studied technique by which solids such as silica can be formed in situ. Previous works used a simple acid-catalyzed sol-gel reaction to create brittle, glassy ionogels. Here, both the range of products that can be accomplished through sol-gel processing and the understanding of interactions between ILs and the sol-gel reaction network are greatly expanded. This work introduces novel ionogel materials, including soft and compliant silica-supported ionogels and PDMS-supported ionogels. The impacts of the reactive formulation, IL identity, and casting time are detailed. It is demonstrated that variations in formulation can lead to rapid gelation and open pore structures in the silica scaffold or slow gelation and more dense silica

Enhanced mechanical properties and increased corrosion resistance of a biodegradable magnesium alloy by plasma electrolytic oxidation (PEO).

PubMed

White, Leon; Koo, Youngmi; Neralla, Sudheer; Sankar, Jagannathan; Yun, Yeoheung

2016-06-01

We report the enhanced mechanical properties of AZ31 magnesium alloys by plasma electrolytic oxidation (PEO) coating in NaOH, Na 2 SiO 3 , KF and NaH 2 PO 4 ·2H 2 O containing electrolytes. Mechanical properties including wear resistance, surface hardness and elastic modulus were increased for PEO-coated AZ31 Mg alloys (PEO-AZ31). DC polarization in Hank's solution indicating that the corrosion resistance significantly increased for PEO-coating in KF-contained electrolyte. Based on these results, the PEO coating method shows promising potential for use in biodegradable implant applications where tunable corrosion and mechanical properties are needed.

Effects of sulfate and nitrate anions on aluminum corrosion in slightly alkaline solution

NASA Astrophysics Data System (ADS)

Li, Shengyi; Church, Benjamin C.

2018-05-01

The corrosion mechanisms and kinetics of AA1085 in Li2SO4 and LiNO3 aqueous rechargeable lithium-ion battery electrolytes were investigated at pH 11 using chronoamperometry. The corrosion kinetics of AA1085 is controlled by the electrolyte concentration level and the anodic potentials. AA1085 is susceptible to crystallographic pitting corrosion in Li2SO4 electrolytes. The rates of pit nucleation and pit growth both decreased at higher Li2SO4 concentrations or at lower anodic potentials. AA1085 passivates against pitting corrosion in LiNO3 electrolytes due to the formation of a thick, uniform corrosion product layer. The growth rate of the passive film was slightly enhanced by increasing the electrolyte concentration and anodic potentials. X-ray photoelectron spectroscopy spectra showed the formation of a thin sulfate-incorporated passive film on the electrode, which comprises Al2(SO)418H2O, Al(OH)SO4 and Al(OH)3, before the occurrence of pitting growth in 2 M Li2SO4 electrolyte. The thick corrosion product layer formed in 5 M LiNO3 electrolyte was composed of Al(OH)3 and AlOOH. Raman spectroscopy on deionized water, LiOH solution, Li2SO4 and LiNO3 electrolytes depicted changes of solution structure with increasing electrolyte concentration. The influence of extrinsic and intrinsic factors on the corrosion kinetics of AA1085 in Li2SO4 and LiNO3 electrolytes at pH 11 are discussed in detail.

Ceramic electrolyte coating and methods

DOEpatents

Seabaugh, Matthew M [Columbus, OH; Swartz, Scott L [Columbus, OH; Dawson, William J [Dublin, OH; McCormick, Buddy E [Dublin, OH

2007-08-28

Aqueous coating slurries useful in depositing a dense coating of a ceramic electrolyte material (e.g., yttrium-stabilized zirconia) onto a porous substrate of a ceramic electrode material (e.g., lanthanum strontium manganite or nickel/zirconia) and processes for preparing an aqueous suspension of a ceramic electrolyte material and an aqueous spray coating slurry including a ceramic electrolyte material. The invention also includes processes for depositing an aqueous spray coating slurry including a ceramic electrolyte material onto pre-sintered, partially sintered, and unsintered ceramic substrates and products made by this process.

Hydrofluoroether electrolytes for lithium-ion batteries: Reduced gas decomposition and nonflammable

NASA Astrophysics Data System (ADS)

Nagasubramanian, Ganesan; Orendorff, Christopher J.

2011-10-01

The optimum combination of high energy density at the desired power sets lithium-ion battery technology apart from the other well known secondary battery chemistries. However, this is besieged by thermal instability of the electrolyte. This "Achilles heel" still remains a significant safety issue and unless this propensity is improved the promise of widespread adoption of Li-ion batteries for Transportation application may not be realized. With this in mind we launched a systematic study to evaluate fluoro solvents that are known to be nonflammable, for thermal and electrochemical performances. We investigated hydro-fluoro-ethers (HFE) (1) 2-trifluoromethyl-3-methoxyperfluoropentane {TMMP} and (2) 2-trifluoro-2-fluoro-3-difluoropropoxy-3-difluoro-4-fluoro-5-trifluoropentane {TPTP} in Sandia-built cells. Thermal properties under near abuse conditions that exist in thermal runaway environment and the electrochemical characteristics for these electrolytes were measured. In the thermal ramp (TR) measurement, EC:DEC:TPTP-1 M LiBETI (or TFSI or LiPF6) electrolytes exhibited no ignition/fire. Similar behavior was observed for the EC:DEC:TMMP-1 M LiBETI. Further, in ARC studies the HFE electrolytes generated less gas by 50% compared to the EC:EMC-1.2 M LiPF6 {CAR-1} electrolyte. Although in all cases the HFEs generated less gas, the onset of gas generation appears to depend on the salt. For the LiBETI and TFSI containing HFEs the onset is pushed out by ∼80 °C and for the LiPF6 the onset is comparable to that of the CAR-1. The solution ionic conductivity of these HFE electrolytes was lower (4-5 times) than that of the CAR-1 electrolyte however, the electrochemical performance was comparable. For example, full cells in 2032 type coin cells containing LiMN0.33Ni0.33Co0.33O2 cathode and carbon anode showed around 5 mA h capacity and the computed specific capacity was ∼154 mA h for all the electrolytes. In half-cells against lithium the cathode and anode gave specific

Anomalous Protein-Protein Interactions in Multivalent Salt Solution.

PubMed

Pasquier, Coralie; Vazdar, Mario; Forsman, Jan; Jungwirth, Pavel; Lund, Mikael

2017-04-13

The stability of aqueous protein solutions is strongly affected by multivalent ions, which induce ion-ion correlations beyond the scope of classical mean-field theory. Using all-atom molecular dynamics (MD) and coarse grained Monte Carlo (MC) simulations, we investigate the interaction between a pair of protein molecules in 3:1 electrolyte solution. In agreement with available experimental findings of "reentrant protein condensation", we observe an anomalous trend in the protein-protein potential of mean force with increasing electrolyte concentration in the order: (i) double-layer repulsion, (ii) ion-ion correlation attraction, (iii) overcharge repulsion, and in excess of 1:1 salt, (iv) non Coulombic attraction. To efficiently sample configurational space we explore hybrid continuum solvent models, applicable to many-protein systems, where weakly coupled ions are treated implicitly, while strongly coupled ones are treated explicitly. Good agreement is found with the primitive model of electrolytes, as well as with atomic models of protein and solvent.

Effect of Divalent Electrolytes on Electroosmotic Flow

NASA Astrophysics Data System (ADS)

Li, Haifeng; Gnanaprakasam, Pradeep

2005-11-01

Electroosmotic flow (EOF) is of importance in micro- and nanofluidic applications. Recent numerical results [Zheng et al. (2003) Electrophoresis 24, 3006] suggest that the addition of even trace amounts of divalent counterions can greatly affect the velocity and electric potential distribution for EOF of a nominally monovalent electrolyte solution, nearly halving the flow rate in 20 nm channels. Scaled experiments were therefore carried out for steady and fully-developed EOF of buffered aqueous mono- and divalent electrolyte mixtures through fused silica microchannels. Nano-particle image velocimetry (nPIV), based upon evanescent-wave illumination of colloidal tracers, was used to obtain velocity data within about 300 nm of the wall. In all cases, the thickness of the electric double layer, defined as the distance from the wall where the velocity and electric potential recover to 99% of their freestream values, is of O(10 nm), or much less than the channel dimension of O(10 μm). The nPIV results are compared with predictions from an asymptotic perturbation analysis.

Microstructure, thickness and sheet resistivity of Cu/Ni thin film produced by electroplating technique on the variation of electrolyte temperature

NASA Astrophysics Data System (ADS)

Toifur, M.; Yuningsih, Y.; Khusnani, A.

2018-03-01

In this research, it has been made Cu/Ni thin film produced with electroplating technique. The deposition process was done in the plating bath using Cu and Ni as cathode and anode respectively. The electrolyte solution was made from the mixture of HBrO3 (7.5g), NiSO4 (100g), NiCl2 (15g), and aquadest (250 ml). Electrolyte temperature was varied from 40°C up to 80°C, to make the Ni ions in the solution easy to move to Cu cathode. The deposition was done during 2 minutes on the potential of 1.5 volt. Many characterizations were done including the thickness of Ni film, microstructure, and sheet resistivity. The results showed that at all samples Ni had attacked on the Cu substrate to form Cu/Ni. The raising of electrolyte temperature affected the increasing of Ni thickness that is the Ni thickness increase with the increasing electrolyte temperature. From the EDS spectrum, it can be informed that samples already contain Ni and Cu elements and NiO and CuO compounds. Addition element and compound are found for sample Cu/Ni resulted from 70° electrolyte temperature of Ni deposition, that are Pt and PtO2. From XRD pattern, there are several phases which have crystal structure i.e. Cu, Ni, and NiO, while CuO and PtO2 have amorphous structure. The sheet resistivity linearly decreases with the increasing electrolyte temperature.

Solubility of lysozyme in polyethylene glycol-electrolyte mixtures: the depletion interaction and ion-specific effects.

PubMed

Boncina, Matjaz; Rescic, Jurij; Vlachy, Vojko

2008-08-01

The solubility of aqueous solutions of lysozyme in the presence of polyethylene glycol and various alkaline salts was studied experimentally. The protein-electrolyte mixture was titrated with polyethylene glycol, and when precipitation of the protein occurred, a strong increase of the absorbance at 340 nm was observed. The solubility data were obtained as a function of experimental variables such as protein and electrolyte concentrations, electrolyte type, degree of polymerization of polyethylene glycol, and pH of the solution; the last defines the net charge of the lysozyme. The results indicate that the solubility of lysozyme decreases with the addition of polyethylene glycol; the solubility is lower for a polyethylene glycol with a higher degree of polymerization. Further, the logarithm of the protein solubility is a linear function of the polyethylene glycol concentration. The process is reversible and the protein remains in its native form. An increase of the electrolyte (NaCl) concentration decreases the solubility of lysozyme in the presence and absence of polyethylene glycol. The effect can be explained by the screening of the charged amino residues of the protein. The solubility experiments were performed at two different pH values (pH = 4.0 and 6.0), where the lysozyme net charge was +11 and +8, respectively. Ion-specific effects were systematically investigated. Anions such as Br(-), Cl(-), F(-), and H(2)PO(4)(-) (all in combination with Na(+)), when acting as counterions to a protein with positive net charge, exhibit a strong effect on the lysozyme solubility. The differences in protein solubility for chloride solutions with different cations Cs(+), K(+), and Na(+) (coions) were much smaller. The results at pH = 4.0 show that anions decrease the lysozyme solubility in the order F(-) < H(2)PO(4)(-) < Cl(-) < Br(-) (the inverse Hofmeister series), whereas cations follow the direct Hofmeister series (Cs(+) < K(+) < Na(+)) in this situation.

Electrolytic decontamination of conductive materials

NASA Astrophysics Data System (ADS)

Campbell, George M.; Nelson, Timothy O.; Parker, John L.; Getty, Richard H.; Hergert, Tom R.; Lindahl, Kirk A.; Peppers, Larry G.

1994-10-01

Using the electrolytic method, we have demonstrated removal of Pu and Am from contaminated conductive material. At EG and G /Rocky Flats, we electrolytically decontaminated stainless steel. Results from this work show removal of fixed contamination, including the following geometries: planar, large radius, bolt holes, glove ports, and protruding studs. More specifically, fixed contamination was reduced from levels ranging from greater than 1 000 000 counts per minute (cpm) down to levels ranging from 1500 to 250 cpm using the electrolytic method. More recently, the electrolytic work has continued at Los Alamos National Laboratory as a joint project with EG and G/Rocky Flats. Impressively, electrolytic decontamination of Pu /Am from U surfaces (10 sq cm per side) shows decreases in swipable contamination from 500 000-1 500 000 disintegrations per minute (dpm) down to 0-2 dpm. Moreover, the solid waste product of the electrolytic method is reduced in volume by more than 50 times compared with the liquid waste produced by the previous U decontamination method -- a hot concentrated acid spray leach process.

Investigation of the complex electroviscous effects on electrolyte (single and multiphase) flow in porous medi.

NASA Astrophysics Data System (ADS)

Bolet, A. J. S.; Linga, G.; Mathiesen, J.

2017-12-01

Surface charge is an important control parameter for wall-bounded flow of electrolyte solution. The electroviscous effect has been studied theoretically in model geometries such as infinite capillaries. However, in more complex geometries a quantification of the electroviscous effect is a non-trival task due to strong non-linarites of the underlying equations. In general, one has to rely on numerical methods. Here we present numerical studies of the full three-dimensional steady state Stokes-Poisson-Nernst-Planck problem in order to model electrolyte transport in artificial porous samples. The simulations are performed using the finite element method. From the simulation, we quantity how the electroviscous effect changes the general flow permeability in complex three-dimensional porous media. The porous media we consider are mostly generated artificially by connecting randomly dispersed cylindrical pores. Furthermore, we present results of electric driven two-phase immiscible flow in two dimensions. The simulations are performed by augmenting the above equations with a phase field model to handle and track the interaction between the two fluids (using parameters corresponding to oil-water interfaces, where oil non-polar). In particular, we consider the electro-osmotic effect on imbibition due to charged walls and electrolyte-solution.

Preparation and electrochemical characterization of polymer electrolytes based on electrospun poly(vinylidene fluoride- co-hexafluoropropylene)/polyacrylonitrile blend/composite membranes for lithium batteries

NASA Astrophysics Data System (ADS)

Raghavan, Prasanth; Zhao, Xiaohui; Shin, Chorong; Baek, Dong-Ho; Choi, Jae-Won; Manuel, James; Heo, Min-Yeong; Ahn, Jou-Hyeon; Nah, Changwoon

Apart from PEO based solid polymer electrolytes, tailor-made gel polymer electrolytes based on blend/composite membranes of poly(vinylidene fluoride- co-hexafluoropropylene) and polyacrylonitrile are prepared by electrospinning using 14 wt% polymer solution in dimethylformamide. The membranes show uniform morphology with an average fiber diameter of 320-490 nm, high porosity and electrolyte uptake. Polymer electrolytes are prepared by soaking the electrospun membranes in 1 M lithium hexafluorophosphate in ethylene carbonate/dimethyl carbonate. Temperature dependent ionic conductivity and their electrochemical performance are studied. The blend/composite polymer electrolytes show good ionic conductivity in the range of 10 -3 S cm -1 at ambient temperature and good electrochemical performance. All the Polymer electrolytes show an anodic stability >4.6 V with stable interfacial resistance with storage time. The prototype cell shows good charge-discharge properties and stable cycle performance with comparable capacity fade compared to liquid electrolyte under the test conditions.

The effect of concentration- and temperature-dependent dielectric constant on the activity coefficient of NaCl electrolyte solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Valiskó, Mónika; Boda, Dezső, E-mail: boda@almos.vein.hu

2014-06-21

Our implicit-solvent model for the estimation of the excess chemical potential (or, equivalently, the activity coefficient) of electrolytes is based on using a dielectric constant that depends on the thermodynamic state, namely, the temperature and concentration of the electrolyte, ε(c, T). As a consequence, the excess chemical potential is split into two terms corresponding to ion-ion (II) and ion-water (IW) interactions. The II term is obtained from computer simulation using the Primitive Model of electrolytes, while the IW term is estimated from the Born treatment. In our previous work [J. Vincze, M. Valiskó, and D. Boda, “The nonmonotonic concentration dependencemore » of the mean activity coefficient of electrolytes is a result of a balance between solvation and ion-ion correlations,” J. Chem. Phys. 133, 154507 (2010)], we showed that the nonmonotonic concentration dependence of the activity coefficient can be reproduced qualitatively with this II+IW model without using any adjustable parameter. The Pauling radii were used in the calculation of the II term, while experimental solvation free energies were used in the calculation of the IW term. In this work, we analyze the effect of the parameters (dielectric constant, ionic radii, solvation free energy) on the concentration and temperature dependence of the mean activity coefficient of NaCl. We conclude that the II+IW model can explain the experimental behavior using a concentration-dependent dielectric constant and that we do not need the artificial concept of “solvated ionic radius” assumed by earlier studies.« less

Calculating the thermodynamic properties of aqueous solutions of alkali metal carboxylates

NASA Astrophysics Data System (ADS)

Rudakov, A. M.; Sergievskii, V. V.; Zhukova, T. V.

2014-06-01

A modified Robinson-Stokes equation with terms that consider the formation of ionic hydrates and associates is used to describe thermodynamic properties of aqueous solutions of electrolytes. The model is used to describe data on the osmotic coefficients of aqueous solutions of alkali metal carboxylates, and to calculate the mean ionic activity coefficients of salts and excess Gibbs energies. The key contributions from ionic hydration and association to the nonideality of solutions is determined by analyzing the contributions of various factors. Relations that connect the hydration numbers of electrolytes with the parameters of the Pitzer-Mayorga equation and a modified Hückel equation are developed.

Aqueous liquid feed organic fuel cell using solid polymer electrolyte membrane

NASA Technical Reports Server (NTRS)

Olah, George A. (Inventor); Surampudi, Subbarao (Inventor); Vamos, Eugene (Inventor); Halpert, Gerald (Inventor); Narayanan, Sekharipuram R. (Inventor); Frank, Harvey A. (Inventor); Prakash, G. K. Surya (Inventor)

1997-01-01

A liquid organic fuel cell is provided which employs a solid electrolyte membrane. An organic fuel, such as a methanol/water mixture, is circulated past an anode of a cell while oxygen or air is circulated past a cathode of the cell. The cell solid electrolyte membrane is preferably fabricated from Nafion.TM.. Additionally, a method for improving the performance of carbon electrode structures for use in organic fuel cells is provided wherein a high surface-area carbon particle/Teflon.TM.-binder structure is immersed within a Nafion.TM./methanol bath to impregnate the electrode with Nafion.TM.. A method for fabricating an anode for use in a organic fuel cell is described wherein metal alloys are deposited onto the electrode in an electro-deposition solution containing perfluorooctanesulfonic acid. A fuel additive containing perfluorooctanesulfonic acid for use with fuel cells employing a sulfuric acid electrolyte is also disclosed. New organic fuels, namely, trimethoxymethane, dimethoxymethane, and trioxane are also described for use with either conventional or improved fuel cells.

Potential of mean force between identical charged nanoparticles immersed in a size-asymmetric monovalent electrolyte

NASA Astrophysics Data System (ADS)

Guerrero-García, Guillermo Iván; González-Mozuelos, Pedro; de la Cruz, Mónica Olvera

2011-10-01

In a previous theoretical and simulation study [G. I. Guerrero-García, E. González-Tovar, and M. Olvera de la Cruz, Soft Matter 6, 2056 (2010)], it has been shown that an asymmetric charge neutralization and electrostatic screening depending on the charge polarity of a single nanoparticle occurs in the presence of a size-asymmetric monovalent electrolyte. This effect should also impact the effective potential between two macroions suspended in such a solution. Thus, in this work we study the mean force and the potential of mean force between two identical charged nanoparticles immersed in a size-asymmetric monovalent electrolyte, showing that these results go beyond the standard description provided by the well-known Derjaguin-Landau-Verwey-Overbeek theory. To include consistently the ion-size effects, molecular dynamics (MD) simulations and liquid theory calculations are performed at the McMillan-Mayer level of description in which the solvent is taken into account implicitly as a background continuum with the suitable dielectric constant. Long-range electrostatic interactions are handled properly in the simulations via the well established Ewald sums method and the pre-averaged Ewald sums approach, originally proposed for homogeneous ionic fluids. An asymmetric behavior with respect to the colloidal charge polarity is found for the effective interactions between two identical nanoparticles. In particular, short-range attractions are observed between two equally charged nanoparticles, even though our model does not include specific interactions; these attractions are greatly enhanced for anionic nanoparticles immersed in standard electrolytes where cations are smaller than anions. Practical implications of some of the presented results are also briefly discussed. A good accord between the standard Ewald method and the pre-averaged Ewald approach is attained, despite the fact that the ionic system studied here is certainly inhomogeneous. In general, good

Formation of Reversible Solid Electrolyte Interface on Graphite Surface from Concentrated Electrolytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Dongping; Tao, Jinhui; Yan, Pengfei

2017-02-10

Interfacial phenomena have always been key determinants for the performance of energy storage technologies. The solid electrolyte interfacial (SEI) layer, pervasive on the surfaces of battery electrodes for numerous chemical couples, directly affects the ion transport, charge transfer and lifespan of the entire energy system. Almost all SEI layers, however, are unstable resulting in the continuous consumption of the electrolyte. Typically, this leads to the accumulation of degradation products on/restructuring of the electrode surface and thus increased cell impedance, which largely limits the long-term operation of the electrochemical reactions. Herein, a completely new SEI formation mechanism has been discovered, inmore » which the electrolyte components reversibly self-assemble into a protective surface coating on a graphite electrode upon changing the potential. In contrast to the established wisdom regarding the necessity of employing the solvent ethylene carbonate (EC) to form a protective SEI layer on graphite, a wide range of EC-free electrolytes are demonstrated for the reversible intercalation/deintercalation of Li+ cations within a graphite lattice, thereby providing tremendous flexibility in electrolyte tailoring for battery couples. This novel finding is broadly applicable and provides guidance for how to control interfacial reactions through the relationship between ion aggregation and solvent decomposition at polarized interfaces.« less

Maintaining molten salt electrolyte concentration in aluminum-producing electrolytic cell

DOEpatents

Barnett, Robert J.; Mezner, Michael B.; Bradford, Donald R

2005-01-04

A method of maintaining molten salt concentration in a low temperature electrolytic cell used for production of aluminum from alumina dissolved in a molten salt electrolyte contained in a cell free of frozen crust wherein volatile material is vented from the cell and contacted and captured on alumina being added to the cell. The captured volatile material is returned with alumina to cell to maintain the concentration of the molten salt.

Electrolyte volume effects on electrochemical performance and solid electrolyte interphase in Si-graphite/NMC lithium-ion pouch cells

DOE PAGES

An, Seong Jin; Li, Jianlin; Daniel, Claus; ...

2017-05-15

This study aims to explore the correlations between electrolyte volume, electrochemical performance, and properties of the solid electrolyte interphase in pouch cells with Si-graphite composite anodes. The electrolyte is 1.2 M LiPF 6 in ethylene carbonate:ethylmethyl carbonate with 10 wt.% fluoroethylene carbonate. Single layer pouch cells (100 mAh) were constructed with 15 wt.% Si-graphite/LiNi 0.5Mn 0.3CO 0.2O 2 electrodes. It is found that a minimum electrolyte volume factor of 3.1 times the total pore volume of cell components (cathode, anode, and separator) is needed for better cycling stability. Less electrolyte causes increases in ohmic and charge transfer resistances. Lithium dendritesmore » are observed when the electrolyte volume factor is low. The resistances from the anodes become significant as the cells are discharged. As a result, solid electrolyte interphase thickness grows as the electrolyte volume factor increases and is non-uniform after cycling.« less

Tin Dioxide Electrolyte-Gated Transistors Working in Depletion and Enhancement Modes.

PubMed

Valitova, Irina; Natile, Marta Maria; Soavi, Francesca; Santato, Clara; Cicoira, Fabio

2017-10-25

Metal oxide semiconductors are interesting for next-generation flexible and transparent electronics because of their performance and reliability. Tin dioxide (SnO 2 ) is a very promising material that has already found applications in sensing, photovoltaics, optoelectronics, and batteries. In this work, we report on electrolyte-gated, solution-processed polycrystalline SnO 2 transistors on both rigid and flexible substrates. For the transistor channel, we used both unpatterned and patterned SnO 2 films. Since decreasing the SnO 2  area in contact with the electrolyte increases the charge-carrier density, patterned transistors operate in the depletion mode, whereas unpatterned ones operate in the enhancement mode. We also fabricated flexible SnO 2 transistors that operate in the enhancement mode that can withstand moderate mechanical bending.

The Electrochemical Performance of Silicon Nanoparticles in Concentrated Electrolyte.

PubMed

Chang, Zeng-Hua; Wang, Jian-Tao; Wu, Zhao-Hui; Gao, Min; Wu, Shuai-Jin; Lu, Shi-Gang

2018-06-11

Silicon is a promising material for anodes in energy-storage devices. However, excessive growth of a solid-electrolyte interphase (SEI) caused by the severe volume change during the (de)lithiation processes leads to dramatic capacity fading. Here, we report a super-concentrated electrolyte composed of lithium bis(fluorosulfonyl)imide (LiFSI) and propylene carbonate (PC) with a molar ratio of 1:2 to improve the cycling performance of silicon nanoparticles (SiNPs). The SiNP electrode shows a remarkably improved cycling performance with an initial delithiation capacity of approximately 3000 mAh g -1 and a capacity of approximately 2000 mAh g -1 after 100 cycles, exhibiting about 6.8 times higher capacity than the cells with dilute electrolyte LiFSI-(PC) 8 . Raman spectra reveal that most of the PC solvent and FSI anions are complexed by Li + to form a specific solution structure like a fluid polymeric network. The reduction of FSI anions starts to play an important role owing to the increased concentration of contact ion pairs (CIPs) or aggregates (AGGs), which contribute to the formation of a more mechanically robust and chemically stable complex SEI layer. The complex SEI layer can effectively suppress the morphology evolution of silicon particles and self-limit the excessive growth, which mitigates the crack propagation of the silicon electrode and the deterioration of the kinetics. This study will provide a new direction for screening cycling-stable electrolytes for silicon-based electrodes. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electrolyte measurement device and measurement procedure

DOEpatents

Cooper, Kevin R.; Scribner, Louie L.

2010-01-26

A method and apparatus for measuring the through-thickness resistance or conductance of a thin electrolyte is provided. The method and apparatus includes positioning a first source electrode on a first side of an electrolyte to be tested, positioning a second source electrode on a second side of the electrolyte, positioning a first sense electrode on the second side of the electrolyte, and positioning a second sense electrode on the first side of the electrolyte. current is then passed between the first and second source electrodes and the voltage between the first and second sense electrodes is measured.

Implementation of problem-based learning (PBL) approach to improve student’s academic achievement and creativity on the topic of electrolyte and non-electrolyte solutions at vocational school

NASA Astrophysics Data System (ADS)

Wahyu, W.; Kurnia; Syaadah, R. S.

2018-05-01

The purpose of study was to investigate the implementation of PBL to improve student’s academic achievement and creativity on the topic of electrolyte and non-electrolye solutions. This study was conducted as a descriptive method with case study design. Subject of this study consisted of 30 students in the class X. Instruments used in the study included tests and observation sheets. Student’s achievement changes is calculated using N-gain formula, hereafter, the data that have been processed then was analyzed descriptively. The results showed that generally academic achievement and creativity of students has increased as indicated by the value of N-gain (0.667; 0.656). The results of the study also showed that there was a correlation with the moderate category between the academic achievement and the student’s creative thinking as indicated by (r = 0.413), meanwhile, the relationship between academic achievement and creativity(r = 0.340) that belongs to the weak category. Implementation of PBL had a good response from students with percentage 80.3%. Based on these findings, PBL is recommended to be applied on the learning process for other chemistry topics that suitable in term of characteristics between learning materials and PBL stages in order to develop academic achievement and creativity of students.

Effect of pH and Electrolytes on Adsorption of 2,4-D onto Kaolinite

NASA Astrophysics Data System (ADS)

Sharma, A.; Kawamoto, K.; Komatsu, T.; Moldrup, P.

2006-12-01

The fate and transport of pesticides in soil can be greatly influenced by adsorption onto clay minerals such as kaolinite. The ionic pesticide 2,4-D (2,4-dichlorophenoxyacetic acid) is one of the most commonly used herbicides. The purpose of this study is to investigate the effect of electrolytes and pH on the adsorption of 2,4- D onto kaolinite. The adsorption coefficient (Kd) of 2,4-D on two types of kaolinite was measured in batch experiments using water and 4 different electrolytes (0.005M CaSO4, 0.005M CaCl2, 0.01M KCl, and 0.01M NaCl). The experiments were carried out with 0.5 g kaolinite at a solid:liquid ratio of 1:20 and at different pH (1.9-6.3). The pH of the solution was controlled by addition of 0.2N of HCl. X-ray diffraction analysis of both kaolinite with and without adsorbed 2,4-D was also done to understand the location of 2,4-D adsorption. The effects of pH and electrolytes on Kd were compared and possible adsorption mechanisms were revealed for 2,4-D adsorption onto the two different types of kaolinite. The results implied that 2,4-D adsorption was higher for an electrolyte solution with monovalent cation than with divalent cation for one type of kaolinite, while no such trend was observed for the other kaolinite. The adsorption of 2,4-D increased significantly with decreasing pH for both types of kaolinite.

Optimization of electrochemical dechlorination of trichloroethylene in reducing electrolytes

PubMed Central

Mao, Xuhui; Ciblak, Ali; Baek, Kitae; Amiri, Mohammad; Loch-Caruso, Rita; Alshawabkeh, Akram N.

2012-01-01

Electrochemical dechlorination of trichloroethylene (TCE) in aqueous solution is investigated in a closed, liquid-recirculation system. The anodic reaction of cast iron generates ferrous species, creating a chemically reducing electrolyte (negative ORP value). The reduction of TCE on the cathode surface is enhanced under this reducing electrolyte because of the absence of electron competition. In the presence of the iron anode, the performances of different cathodes are compared in a recirculated electrolysis system. The copper foam shows superior capability for dechlorination of aqueous TCE. Electrolysis by cast iron anode and copper foam cathode is further optimized though a multivariable experimental design and analysis. The conductivity of the electrolyte is identified as an important factor for both final elimination efficiency (FEE) of TCE and specific energy consumption. The copper foam electrode exhibits high TCE elimination efficiency in a wide range of initial TCE concentration. Under coulostatic conditions, the optimal conditions to achieve the highest FEE are 9.525 mm thick copper foam electrode, 40 mA current and 0.042 mol L−1 Na2SO4. This novel electrolysis system is proposed to remediate groundwater contaminated by chlorinated organic solvents, or as an improved iron electrocoagulation process capable of treating the wastewater co-contaminated with chlorinated compounds. PMID:22264798

Lithium-Ion Electrolytes Containing Phosphorous-Based, Flame-Retardant Additives

NASA Technical Reports Server (NTRS)

Smart, Marshall C.; Smith, Kiah A.; Bugga, Ratnakumar V.; Prakash, G. K. Surya

2010-01-01

study displayed good performance over a wide temperature range, good cycle life characteristics, and are expected to have improved safety characteristics, such as low flammability. Of the electrolytes studied, 1.0 M LiPF6 in EC+EMC+DEP (20:75:5 v/v %) and 1.0 M LiPF6 in EC+EMC+DPP (20:75:5 v/v %) displayed the best operation at low temperatures, whereas the electrolyte containing triphenylphosphite displayed the best cycle life performance compared to the baseline solution. It is anticipated that further improvements can be made to the life characteristics with the incorporation of a SET promoters (such as VC, vinylene carbonate), which will likely inhibit the decomposition of the flame-retardant additives.

Influence of process parameters on plasma electrolytic surface treatment of tantalum for biomedical applications

NASA Astrophysics Data System (ADS)

Sowa, Maciej; Woszczak, Maja; Kazek-Kęsik, Alicja; Dercz, Grzegorz; Korotin, Danila M.; Zhidkov, Ivan S.; Kurmaev, Ernst Z.; Cholakh, Seif O.; Basiaga, Marcin; Simka, Wojciech

2017-06-01

This work aims to quantify the effect of anodization voltage and electrolyte composition used during DC plasma electrolytic oxidation (PEO), operated as a 2-step process, on the surface properties of the resulting oxide coatings on tantalum. The first step consisted of galvanostatic anodization (150 mA cm-2) of the tantalum workpiece up to several limiting voltages (200, 300, 400 and 500 V). After attaining the limiting voltage, the process was switched to voltage control, which resulted in a gradual decrease of the anodic current density. The anodic treatment was realized in a 0.5 M Ca(H2PO2)2 solution, which was then modified by the addition of 1.15 M Ca(HCOO)2 as well as 1.15 M and 1.5 M Mg(CH3COO)2. The increasing voltage of anodization led to the formation of thicker coatings, with larger pores and enriched with electrolytes species to a higher extent. The solutions containing HCOO- and CH3COO- ions caused the formation of coatings which were slightly hydrophobic (high contact angle). In the case of the samples anodized up to 500 V, scattered crystalline deposits were observed. Bioactive phases, such as hydroxyapatite, were detected in the treated oxide coatings by XRD and XPS.

Molten salt electrolyte separator

DOEpatents

Kaun, Thomas D.

1996-01-01

A molten salt electrolyte/separator for battery and related electrochemical systems including a molten electrolyte composition and an electrically insulating solid salt dispersed therein, to provide improved performance at higher current densities and alternate designs through ease of fabrication.

Characterization of chitosan-starch blend based biopolymer electrolyte doped with ammonium nitrate

NASA Astrophysics Data System (ADS)

Shaffie, Ahmad Hakimi; Khiar, Azwani Sofia Ahmad

2018-06-01

Polymer electrolyte is an ionic conductor formed by dissolving salt in polymer host. In this work, starch/chitosan blend based polymer electrolyte was prepared with different weight percentage of Ammonium Nitrate (NH4NO3) via solution casting technique. The film was characterized by impedance spectroscopy HIOKI 3531- 01 LCR Hi-Tester to measure its ionic conductivity over a wide range of frequency between 50Hz-5MHz and at ambient temperature. Sample with 35 wt% of NH4NO3 shows the highest conductivity of (6.34 ± 1.52) = 10-7 Scm-1. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy were used to correlate the ionic conductivity results.

Solid lithium electrolyte via addition of lithium salts to metal-organic frameworks

DOEpatents

Wiers, Brian M.; Balsara, Nitash P.; Long, Jeffrey R.

2016-03-29

Various embodiments of the invention disclose that the uptake of LiO.sup.iPr in Mg.sub.2(dobdc) (dobdc.sup.4-=1,4-dioxido-2,5-benzenedicarboxylate) followed by soaking in a typical electrolyte solution leads to a new solid lithium electrolyte Mg.sub.2(dobdc).0.35LiO.sup.iPr.0.25LiBF.sub.4.EC.DEC. Two-point ac impedance data show a pressed pellet of this material to have a conductivity of 3.1.times.10.sup.-4 S/cm at 300 K. In addition, the results from variable-temperature measurements reveal an activation energy of approximately 0.15 eV, while single-particle data suggest that intraparticle transport dominates conduction.

Solid lithium electrolyte via addition of lithium salts to metal-organic frameworks

DOEpatents

Wiers, Brian M.; Balsara, Nitash P.; Long, Jeffrey R.

2016-12-20

Various embodiments of the invention disclose that the uptake of LiO.sup.iPr in Mg.sub.2(dobdc) (dobdc.sup.4-=1,4-dioxido-2,5-benzenedicarboxylate) followed by soaking in a typical electrolyte solution leads to a new solid lithium electrolyte Mg.sub.2(dobdc).0.35LiO.sup.iPr.0.25LiBF.sub.4.EC.DEC. Two-point ac impedance data show a pressed pellet of this material to have a conductivity of 3.1.times.10.sup.-4 S/cm at 300 K. In addition, the results from variable-temperature measurements reveal an activation energy of approximately 0.15 eV, while single-particle data suggest that intraparticle transport dominates conduction.

Control of Screening of a Charged Particle in Electrolytic Aqueous Paul Trap

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Jae Hyun nmn; Krstic, Predrag S

2011-01-01

Individual charged particles could be trapped and confined in the combined radio-frequency and DC quadrupole electric field of an aqueous Paul trap. Viscosity of water improves confinement and extends the range of the trap parameters which characterize the stability of the trap. Electrolyte, if present in aqueous solution, may screen the charged particle and thus partially or fully suppress electrophoretic interaction with the applied filed, possibly reducing it to a generally much weaker dielectrophoretic interaction with an induced dipole. Applying molecular dynamics simulation we show that the quadrupole field has a different affects at the electrolyte ions and at muchmore » heavier charged particle, effectively eliminating the screening effect and reinstating the electrophoretic confinement.« less

Polymer Electrolytes for Lithium/Sulfur Batteries

PubMed Central

Zhao, Yan; Zhang, Yongguang; Gosselink, Denise; Doan, The Nam Long; Sadhu, Mikhail; Cheang, Ho-Jae; Chen, Pu

2012-01-01

This review evaluates the characteristics and advantages of employing polymer electrolytes in lithium/sulfur (Li/S) batteries. The main highlights of this study constitute detailed information on the advanced developments for solid polymer electrolytes and gel polymer electrolytes, used in the lithium/sulfur battery. This includes an in-depth analysis conducted on the preparation and electrochemical characteristics of the Li/S batteries based on these polymer electrolytes. PMID:24958296

Direct Observation of Virtual Electrode Formation Through a Novel Electrolyte-to-Electrode Transition

NASA Astrophysics Data System (ADS)

Siegel, David; El Gabaly, Farid; Bartelt, Norman; McCarty, Kevin

2014-03-01

Novel electrochemical solutions to problems in energy storage and transportation can drive renewable energy to become an economically viable alternative to fossil fuels. In many electrochemical systems, the behavior of a device can be fundamentally limited by the surface area of a triple phase boundary, the boundary region where a gas-phase species, electrode, and electrolyte coincide. When the electrode is an ionic insulator the triple phase boundary is typically a one-dimensional boundary with nanometer-scale thickness: ions cannot transport through the electrode, while electrons cannot be transported through the electrolyte. Here we present direct experimental measurements of a novel electrolyte-to-electrode transition with photoemission electron microscopy, and observe that the surface of an ionically conductive, electronically insulative solid oxide electrolyte undergoes a transition into a mixed electron-ion conductor in the vicinity of a metal electrode. Our direct experimental measurements allow us to characterize this system and address the mechanisms of ionic reactions and transport through comparisons with theoretical modeling to provide us with a physical picture of the processes involved. Our results provide insight into one of the mechanisms of ion transport in an electrochemical cell that may be generalizable to other systems.

Multiple-membrane multiple-electrolyte redox flow battery design

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yan, Yushan; Gu, Shuang; Gong, Ke

A redox flow battery is provided. The redox flow battery involves multiple-membrane (at least one cation exchange membrane and at least one anion exchange membrane), multiple-electrolyte (one electrolyte in contact with the negative electrode, one electrolyte in contact with the positive electrode, and at least one electrolyte disposed between the two membranes) as the basic characteristic, such as a double-membrane, triple electrolyte (DMTE) configuration or a triple-membrane, quadruple electrolyte (TMQE) configuration. The cation exchange membrane is used to separate the negative or positive electrolyte and the middle electrolyte, and the anion exchange membrane is used to separate the middle electrolytemore » and the positive or negative electrolyte.« less

Electrochemical performance and interfacial properties of Li-metal in lithium bis(fluorosulfonyl)imide based electrolytes.

PubMed

Younesi, Reza; Bardé, Fanny

2017-11-21

Successful usage of lithium metal as the negative electrode or anode in rechargeable batteries can be an important step to increase the energy density of lithium batteries. Performance of lithium metal in a relatively promising electrolyte solution composed of lithium bis(fluorosulfonyl)imide (LiN(SO 2 F) 2 ; LiFSI) salt dissolved in 1,2-dimethoxyethane (DME) is here studied. The influence of the concentration of the electrolyte salt -1 M or 4 M LiFSI- is investigated by varying important electrochemical parameters such as applied current density and plating capacity. X-ray photoelectron spectroscopy analysis as a surface sensitive technique is here used to analyze that how the composition of the solid electrolyte interphase varies with the salt concentration and with the number of cycles.

Composition of highly concentrated silicate electrolytes and ultrasound influencing the plasma electrolytic oxidation of magnesium

NASA Astrophysics Data System (ADS)

Simchen, F.; Rymer, L.-M.; Sieber, M.; Lampke, T.

2017-03-01

Magnesium and its alloys are increasingly in use as lightweight construction materials. However, their inappropriate corrosion and wear resistance often prevent their direct practical use. The plasma electrolytic oxidation (PEO) is a promising, environmentally friendly method to improve the surface characteristics of magnesium materials by the formation of oxide coatings. These PEO layers contain components of the applied electrolyte and can be shifted in their composition by increasing the concentration of the electrolyte constituents. Therefore, in contrast to the use of conventional low concentrated electrolytes, the process results in more stable protective coatings, in which electrolyte species are the dominating constitutes. In the present work, the influence of the composition of highly concentrated alkaline silicate electrolytes with additives of phosphate and glycerol on the quality of PEO layers on the magnesium alloy AZ31 was examined. The effect of ultrasound coupled into the electrolyte bath was also considered. The process was monitored by recording the electrical process variables with a transient recorder and by observation of the discharge phenomena on the sample surface with a camera. The study was conducted on the basis of a design of experiments. The effects of the process parameter variation are considered with regard to the coatings thickness, hardness and corrosion resistance. Information about the statistical significance of the effects of the parameters on the considered properties is obtained by an analysis of variance (ANOVA).

Self-doped microphase separated block copolymer electrolyte

DOEpatents

Mayes, Anne M.; Sadoway, Donald R.; Banerjee, Pallab; Soo, Philip; Huang, Biying

2002-01-01

A polymer electrolyte includes a self-doped microphase separated block copolymer including at least one ionically conductive block and at least one second block that is immiscible in the ionically conductive block, an anion immobilized on the polymer electrolyte and a cationic species. The ionically conductive block provides a continuous ionically conductive pathway through the electrolyte. The electrolyte may be used as an electrolyte in an electrochemical cell.

Effect of Al2O3 in poly(methyl methacrylate) composite polymer electrolytes

NASA Astrophysics Data System (ADS)

Sun, C. C.; You, A. H.; Teo, L. L.; Thong, L. W.

2018-05-01

In this work, the effect of inert fillers on poly(methyl methacrylate) (PMMA) composite polymer electrolytes (CPEs) are investigated. The PMMA-LiCF3SO3-EC-Al2O3 composite polymer electrolytes were prepared using solution casting method at room temperature. Lithium trifluoromethanesulfonate (LiCF3SO3) is used as the electrolyte salt which plays an important role in Li ion transfer. In order to soften the polymer matrix, ethylene carbonate (EC) is introduced into the CPEs to help in the disassociation of lithium salt ion pairs. Nano sized aluminium oxide (Al2O3) is then incorporated to enhance mechanical strength and ionic conductivity of the polymer electrolyte. The optimum of 2 wt.% 50 nm Al2O3 was added into the PMMA polymer electrolyte sample. Through Electrochemical Impedance Spectroscopy (EIS) measurements, the highest ionic conductivity at room temperature is determined as 1.52×10-4 S/cm. FTIR spectra analysis showed CH2 twisting mode at 1383.43 cm-1, C=O stretching mode at 1721.56 cm-1 which proven the interaction between host polymer and lithium salt and CH3 stretching mode at 2981.34 cm-1. XRD analysis had also been performed to study the structural behaviour of the PMMA polymer electrolyte. The intense peak at position 2θ angle of 15.04°, 30.92° and 45.58° occur upon interaction with Al2O3. Lastly, the surface morphology is studied through SEM+EDX analysis.