scholarly journals Electrical Properties and Defect Structure in The Sr-Fe-Co-O System

1995 ◽  
Vol 411 ◽  
Author(s):  
B. Ma ◽  
C.-C. Chao ◽  
J.-H. Park ◽  
C. U. Segret ◽  
U. Balachandran
Keyword(s):  
Ionic Conductivity ◽  
Electrical Properties ◽  
Defect Structure ◽  
Ceramic Membrane ◽  
Ionic Conductivities ◽  
Transference Number ◽  
Total Conductivity ◽  
Interstitial Oxygen ◽  
Oxygen Ions ◽  
Ionic Transference Number

ABSTRACTThe ceramic Sr-Fe-Co-O has potential use as a membrane in gas separation. This material exhibits high conductivity of both electrons and oxygen ions. It allows oxygen to penetrate at high flux rates without other gas components. Electrical properties are essential to understanding the oxygen transport mechanism and defect structure of this material. By using a gas-tight electrochemical cell with flowing air as the reference environment, we were able to achieve an oxygen partial pressure (P02) as low as 10−16 atm. Total and ionic conductivities of Sr-Fe-Co-O have been studied as a function of P02 at elevated temperature. In air, both total and ionic conductivities increase with temperature, while the ionic transference number is almost independent of temperature, with a value of ≈0.4. Experimental results show that ionic conductivity decreases with decreasing P02 at high P02 (≥10−6 atm). This suggests that interstitial oxygen ions and electron holes are the dominant charge carriers. At 800°C in air, total conductivity and ionic conductivity are 17 and 7 S/cm, respectively. Defect dynamics in this system can be understood by means of the trivalence-to-divalence transition of Fe ions when P02 is reduced. By using the conductivity results, we estimated oxygen penneation through a ceramic membrane made of this material. The calculated oxygen permeability agrees with the experimental value obtained directly from an operating methane conversion reactor.

Electronic/Ionic Conductivity and Oxygen Diffusion Coefficient af the Sr-Fe-Co-O System

1995 ◽  
Vol 393 ◽  
Author(s):  
B. Ma ◽  
J.-H. Park ◽  
C. U. Segre ◽  
U. Balachandran
Keyword(s):  
Diffusion Coefficient ◽  
Ionic Conductivity ◽  
Oxygen Diffusion ◽  
Ionic Conductivities ◽  
Transference Number ◽  
Transference Numbers ◽  
Oxygen Diffusion Coefficient ◽  
Ionic Transference Number ◽  
Local Fitting ◽  
Oxide Ion

ABSTRACTOxides in the Sr-Fe-Co-O system exhibit both electronic and ionic conductivities. Recently, the Sr-Fe-Co-O system attracted great attention because of its potential to be used for oxygen-permeable membranes that can operate without electrodes or external electrical circuitry. Electronic and ionic conductivities of two compositions of the Sr-Fe-Co-O system, named SFC-1 and SFC-2, have been measured at various temperatures. The electronic transference number is much greater than the ionic transference number in SFC-1, whereas the electronic and ionic transference numbers are very similar in SFC-2. At 800°C, the electronic and ionic conductivities are ≈76 and ≈4 S•cm−1, respectively, for SFC-1; whereas, for SFC-2, the electronic and ionic conductivities are ≈10 and ∼1 S•cm−1, respectively. By performing a local fitting to the equation σ • T = Aexp(-Ea / kT), we found that the oxide ion activation energies are 0.92 and 0.37 eV, respectively, for SFC-1 and SFC-2. The oxygen diffusion coefficient of SFC-2 is ≈ 9 x 10−7cm2/sec at 900°C.

Ionic Conductivity, Morphology and Transport Number of Lithium Ions in PMMA Based Gel Polymer Electrolytes

2013 ◽  
Vol 334-335 ◽  
pp. 137-142 ◽  
Author(s):  
Lisani Othman ◽  
Khairul Bahiyah Md. Isa ◽  
Zurina Osman ◽  
Rosiyah Yahya
Keyword(s):  
Ionic Conductivity ◽  
Salt Concentration ◽  
Polymer Electrolytes ◽  
Ethylene Carbonate ◽  
Transference Number ◽  
Gel Polymer Electrolytes ◽  
Casting Technique ◽  
Ionic Transference Number ◽  
Temperature Dependence Of Conductivity ◽  
Solution Casting Technique

The gel polymer electrolytes (GPEs) composed of polymethylmethacrylate (PMMA) with lithium trifluoromethanesulfonate (LiCF3SO3) salt dissolved in a binary mixture of ethylene carbonate (EC) and propylene carbonate (PC) organic solvents have been prepared by the solution casting technique. The samples are prepared by varying the salt concentrations from 5 wt.% to 30 wt.%. Impedance spectroscopy measurement has been carried out to determine the ionic conductivity of the samples. The sample containing 25 wt.% of LiCF3SO3salt exhibits the highest room temperature ionic conductivity of 2.56 x 10-3S cm-1. The conductivity of the GPEs has been found to depend on the salt concentration added to the sample, while at higher salt concentration reveals a decrease in the ionic conductivity due to ions association. The temperature dependence of conductivity from 303 K to 373 K is found to obey the Arrhenius law. The ionic transference number,tiof GPEs has been estimated by the DC polarization method and the value is found to be 0.98, 0.93, and 0.97 for the sample containing 25 wt.%, 5 wt.% and 30 wt.% respectively. This result is consistent with the conductivity studies.

scholarly journals The Study of Structural, Impedance and Energy Storage Behavior of Plasticized PVA:MC Based Proton Conducting Polymer Blend Electrolytes

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5030 ◽  
Author(s):  
Shujahadeen B. Aziz ◽  
Iver Brevik ◽  
M. A. Brza ◽  
A. S. F. M. Asnawi ◽  
Elham M. A. Dannoun ◽  
...  
Keyword(s):  
Energy Storage ◽  
Ionic Conductivity ◽  
Specific Capacitance ◽  
High Efficiency ◽  
Ammonium Thiocyanate ◽  
Transference Number ◽  
Equivalent Series Resistance ◽  
Ionic Transference Number ◽  
Main Charge ◽  
Electrochemical Double Layer

In this study, structural characterization, electrical properties and energy storage performance of plasticized polymer electrolytes based on polyvinyl alcohol/methylcellulose/ammonium thiocyanate (PVA/MC-NH4SCN) were carried out. An X-ray diffraction (XRD) study displayed that the plasticized electrolyte system with the uppermost value of direct current (DC) ionic conductivity was the most amorphous system. The electrolyte in the present work realized an ionic conductivity of 2.903 × 10−3 Scm−1 at room temperature. The main charge carrier in the electrolyte was found to be the ions with the ionic transference number (tion) of 0.912, compared to only 0.088 for the electronic transference number (telec). The electrochemical stability potential window of the electrolyte is 2.1 V. The specific capacitance was found to reduce from 102.88 F/g to 28.58 F/g as the scan rate increased in cyclic voltammetry (CV) analysis. The fabricated electrochemical double layer capacitor (EDLC) was stable up to 200 cycles with high efficiency. The specific capacitance obtained for the EDLC by using charge–discharge analysis was 132.7 F/g at the first cycle, which is slightly higher compared to the CV plot. The equivalent series resistance (ESR) increased from 58 to 171 Ω throughout the cycles, which indicates a good electrolyte/electrode contact. Ions in the electrolyte were considered to have almost the same amount of energy during the conduction process as the energy density is approximately at 14.0 Wh/kg throughout the 200 cycles. The power density is stabilized at the range of 1444.3 to 467.6 W/kg as the EDLC completed the cycles.

AC-Impedance, Dynamic mechanical analysis and DSC investigations on poly(methyl methacrylate)–LiTf polymer electrolyte systems

2017 ◽  
Vol 13 (1) ◽  
pp. 4618-4627
Author(s):  
Abdulhamid Mohammed Soliman ◽  
Ezeldain El. Shafee
Keyword(s):  
Ionic Conductivity ◽  
Ethylene Carbonate ◽  
Transference Number ◽  
Ac Impedance ◽  
Mechanical Analysis ◽  
Ionic Conductors ◽  
Casting Technique ◽  
Ionic Transference Number ◽  
The Matrix ◽  
Solution Casting Technique

Gel polymer electrolytes synthesized from Poly(methylmethacrylate) (PMMA) as the host, ethylene carbonate (EC)/propylene carbonate (PC) as plasticizer and LiCF3SO3 (LiTf) as a salt has been prepared using solution casting technique. X-ray characterization confirms the complete dissociation of the LiTf salt in the gel polymer. The effect of LiTf  salt on ionic conductivity, ionic transference number (tion) and  mechanical characteristics were investigated. The ac impedance has been studied to evaluate the ionic conductivity. It was observed that the ionic conductivity of the prepared gel reached the highest value of  6.60 x 10-5 S/cm at 10.2 wt.% (1M) of LiTf salt. The temperature dependence studies showed that the samples were ionic conductors and seemed to obey the Vogel–Tamman–Fulcher (VTF) rule.  Dynamic mechanical  analysis (DMA) indicates that  the LiTf salt induces a remarkable increase in the storage modulus of the matrix at temperatures above the glass transition (rubbery plateau region).

Ionic Conductivity, Morphology and Transference Number of Sodium Ion in PMMA Based Gel Polymer Electrolytes

2013 ◽  
Vol 594-595 ◽  
pp. 696-701 ◽  
Author(s):  
Lisani Othman ◽  
Khairul Bahiyah Md. Isa ◽  
Woon Gie Chong ◽  
Nurul Husna Zainol ◽  
Siti Mariam Samin ◽  
...  
Keyword(s):  
Ionic Conductivity ◽  
Salt Concentration ◽  
Polymer Electrolytes ◽  
Ethylene Carbonate ◽  
Transference Number ◽  
Gel Polymer Electrolytes ◽  
Casting Technique ◽  
Ionic Transference Number ◽  
Temperature Dependence Of Conductivity ◽  
Sodium Trifluoromethanesulfonate

The gel polymer electrolytes (GPEs) composed of polymethylmethacrylate (PMMA) with sodium trifluoromethanesulfonate (NaCF3SO3) salt dissolved in a binary mixture of ethylene carbonate (EC) and propylene carbonate (PC) organic solvents have been prepared by solution casting technique. The samples are prepared by varying the salt concentrations from 5 wt.% to 30 wt.%. Impedance spectroscopy measurement has been carried out to determine the ionic conductivity of the GPE samples. The sample containing 20 wt.% of NaCF3SO3salt exhibits the highest room temperature ionic conductivity of 3.10 x 10-3S cm-1. The conductivity of the GPEs has been found to depend on the salt concentration added to the sample though at higher salt concentration reveals decreasing in ionic conductivity due to ions association. The temperature dependence of conductivity from 303 K to 373 K is found to obey the Arrhenius rule. The ionic transference number, ti of GPEs has been estimated by DC polarization method and the value is found to be 0.95, 0.99, and 0.97 for the sample containing 5 wt.%, 20 wt.% and 30 wt.% respectively. This result is consistent with the conductivity studies.

scholarly journals Silicon Substituted Lithium Stannum Phosphate Ceramic Electrolytes: Structural, Electrical and Electrochemical Properties

2020 ◽  
Vol 17 (2) ◽  
pp. 191
Author(s):  
Noriah Ab Wahab ◽  
Nurul Akmaliah Dzulkurnain ◽  
Nur Amalina Mustaffa ◽  
Nor Sabirin Mohamed
Keyword(s):  
Ionic Conductivity ◽  
Electrochemical Properties ◽  
Sol Gel ◽  
Linear Sweep Voltammetry ◽  
Transference Number ◽  
Ionic Mobility ◽  
Ionic Transference Number ◽  
Ceramic Electrolytes ◽  
Total Ionic Conductivity ◽  
Temperature Water

Structural, electrical and electrochemical properties of silicon (Si) substituted NASICON-structured lithium stannum phosphate, Li1+ySn2P3-ySiyO12 with 0 < y < 1 that was prepared by the low-temperature water-based sol-gel method has been investigated. From the structural analysis, all samples in the system displayed rhombohedral  symmetry. The total ionic conductivity, σt, and ionic mobility, µ was increased with the increase of silicon content, y. A high ionic conductivity value of 6.05 × 10-5 S cm-1 exhibited at y = 0.5 with a temperature of 500 °C. Linear sweep voltammetry analysis showed that the sample was electrochemically stable up to 5.1 V. Meanwhile, the ionic transference number value of the sample was 0.99, suggesting that the majority of mobile charge carriers were predominantly due to ions. Thus, from these results, it indicated that silicon substitution in LiSn2P3O12 ceramic electrolytes is significantly enhanced the electrical and electrochemical properties.

How Certain Are the Reported Ionic Conductivities of Thiophosphate-Based Solid Electrolytes? an Interlaboratory Study

2020 ◽  
Author(s):  
Saneyuki Ohno ◽  
Tim Bernges ◽  
Johannes Buchheim ◽  
Marc Duchardt ◽  
Anna-Katharina Hatz ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Ionic Conductivity ◽  
Relative Standard Deviation ◽  
Solid Electrolytes ◽  
Ionic Conductivities ◽  
Ionic Conductors ◽  
Energy Storage Devices ◽  
Activation Barriers ◽  
Storage Devices ◽  
Relative Standard

<p>Owing to highly conductive solid ionic conductors, all-solid-state batteries attract significant attention as promising next-generation energy storage devices. A lot of research is invested in the search and optimization of solid electrolytes with higher ionic conductivity. However, a systematic study of an <i>interlaboratory reproducibility</i> of measured ionic conductivities and activation energies is missing, making the comparison of absolute values in literature challenging. In this study, we perform an uncertainty evaluation via a Round Robin approach using different Li-argyrodites exhibiting orders of magnitude different ionic conductivities as reference materials. Identical samples are distributed to different research laboratories and the conductivities and activation barriers are measured by impedance spectroscopy. The results show large ranges of up to 4.5 mScm<sup>-1</sup> in the measured total ionic conductivity (1.3 – 5.8 mScm<sup>-1</sup> for the highest conducting sample, relative standard deviation 35 – 50% across all samples) and up to 128 meV for the activation barriers (198 – 326 meV, relative standard deviation 5 – 15%, across all samples), presenting the necessity of a more rigorous methodology including further collaborations within the community and multiplicate measurements.</p>

Solid Polymer Electrolytes from Crosslinked PEG and Dilithium N,N'-Bis(trifluoromethanesulfonyl)perfluoroalkane-1,ω-disulfonamide and Lithium Bis(trifluoromethanesulfonyl)imide Salts

2008 ◽  
Vol 73 (12) ◽  
pp. 1777-1798 ◽  
Author(s):  
Olt E. Geiculescu ◽  
Rama V. Rajagopal ◽  
Emilia C. Mladin ◽  
Stephen E. Creager ◽  
Darryl D. Desmarteau
Keyword(s):  
Ionic Conductivity ◽  
Polymer Electrolytes ◽  
Minimum Energy ◽  
Ionic Conductivities ◽  
Solid Polymer Electrolytes ◽  
Solid Polymer ◽  
Segmental Motion ◽  
Concentrated Electrolytes ◽  
Two Factors ◽  
Poly Ethylene

The present work consists of a series of studies with regard to the structure and charge transport in solid polymer electrolytes (SPE) prepared using various new bis(trifluoromethanesulfonyl)imide (TFSI)-based dianionic dilithium salts in crosslinked low-molecular-weight poly(ethylene glycol). Some of the thermal properties (glass transition temperature, differential molar heat capacity) and ionic conductivities were determined for both diluted (EO/Li = 30:1) and concentrated (EO/Li = 10:1) SPEs. Trends in ionic conductivity of the new SPEs with respect to anion structure revealed that while for the dilute electrolytes ionic conductivity is generally rising with increased length of the perfluoroalkylene linking group in the dianions, for the concentrated electrolytes the trend is reversed with respect to dianion length. This behavior could be the result of a combination of two factors: on one hand a decrease in dianion basicity that results in diminished ion pairing and an enhancement in the number of charge carriers with increasing fluorine anion content, thereby increasing ionic conductivity while on the other hand the increasing anion size and concentration produce an increase in the friction/entanglements of the polymeric segments which lowers even more the reduced segmental motion of the crosslinked polymer and decrease the dianion contribution to the overall ionic conductivity. DFT modeling of the same TFSI-based dianionic dilithium salts reveals that the reason for the trend observed is due to the variation in ion dissociation enthalpy, derived from minimum-energy structures, with respect to perfluoroalkylene chain length.

scholarly journals Investigating the Factors Affecting the Ionic Conduction in Nanoconfined NaBH4

Inorganics ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 2
Author(s):  
Xiaoxuan Luo ◽  
Aditya Rawal ◽  
Kondo-Francois Aguey-Zinsou
Keyword(s):  
Ionic Conductivity ◽  
Ionic Conduction ◽  
Metal Hydrides ◽  
Ionic Conductivities ◽  
Effective Strategy ◽  
Li Ion Batteries ◽  
Large Cage ◽  
Factors Affecting ◽  
Li Ion ◽  
Mcm 41

Nanoconfinement is an effective strategy to tune the properties of the metal hydrides. It has been extensively employed to modify the ionic conductivity of LiBH4 as an electrolyte for Li-ion batteries. However, the approach does not seem to be applicable to other borohydrides such as NaBH4, which is found to reach a limited improvement in ionic conductivity of 10−7 S cm−1 at 115 °C upon nanoconfinement in Mobil Composition of Matter No. 41 (MCM-41) instead of 10−8 S cm−1. In comparison, introducing large cage anions in the form of Na2B12H12 naturally formed upon the nanoconfinement of NaBH4 was found to be more effective in leading to higher ionic conductivities of 10−4 S cm−1 at 110 °C.

scholarly journals Structural, Electrical and Electrochemical Properties of Glycerolized Biopolymers Based on Chitosan (CS): Methylcellulose (MC) for Energy Storage Application

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1183
Author(s):  
Shujahadeen B. Aziz ◽  
Ahmad S. F. M. Asnawi ◽  
Mohd Fakhrul Zamani Kadir ◽  
Saad M. Alshehri ◽  
Tansir Ahamad ◽  
...  
Keyword(s):  
Energy Storage ◽  
Ion Transport ◽  
Ammonium Thiocyanate ◽  
Transference Number ◽  
Ionic Mobility ◽  
Transport Parameters ◽  
Ionic Transference Number ◽  
Energy Storage Application ◽  
Electrochemical Double Layer ◽  
Ion Conducting

In this work, a pair of biopolymer materials has been used to prepare high ion-conducting electrolytes for energy storage application (ESA). The chitosan:methylcellulose (CS:MC) blend was selected as a host for the ammonium thiocyanate NH4SCN dopant salt. Three different concentrations of glycerol was successfully incorporated as a plasticizer into the CS–MC–NH4SCN electrolyte system. The structural, electrical, and ion transport properties were investigated. The highest conductivity of 2.29 × 10−4 S cm−1 is recorded for the electrolyte incorporated 42 wt.% of plasticizer. The complexation and interaction of polymer electrolyte components are studied using the FTIR spectra. The deconvolution (DVN) of FTIR peaks as a sensitive method was used to calculate ion transport parameters. The percentage of free ions is found to influence the transport parameters of number density (n), ionic mobility (µ), and diffusion coefficient (D). All electrolytes in this work obey the non-Debye behavior. The highest conductivity electrolyte exhibits the dominancy of ions, where the ionic transference number, tion value of (0.976) is near to infinity with a voltage of breakdown of 2.11 V. The fabricated electrochemical double-layer capacitor (EDLC) achieves the highest specific capacitance, Cs of 98.08 F/g at 10 mV/s by using the cyclic voltammetry (CV) technique.

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