scholarly journals Investigation of Ion and Electron Conduction in the Mixed Ionic-Electronic Conductor- La-Sr-Co-Fe-Oxide (LSCF) Using Alternating Current (AC) and Direct Current (DC) Techniques

2021 ◽  
Author(s):  
Chong Lei ◽  
Michael Simpson ◽  
Anil Virkar
Keyword(s):  
Ionic Conductivity ◽  
Electronic Conductivity ◽  
Electron Conduction ◽  
Oxygen Ion ◽  
Electronic Current ◽  
Mixed Ionic Electronic Conductor ◽  
Measurement Results ◽  
In Series ◽  
Mixed Ionic Electronic Conductors ◽  
Increasing Temperature

Abstract Among many mixed ionic electronic conductors (MIECs), lanthanum strontium cobalt iron oxide (LSCF) has been proven as a promising material for use as cathode in SOFCs. The ion and electron conduction in LSCF need to be studied separately. To measure the ionic conductivity of LSCF, YSZ disks were applied to block the electronic current, and multilayered samples were made with YSZ disks in series with an LSCF disk. Both AC and DC techniques were used for the measurements. An LSCF(porous)/LSCF(dense)/LSCF(porous) bar-shaped sample was made to measure the electronic conductivity of LSCF. DC technique was utilized for the measurement. Results show that the ionic conductivity of LSCF is much lower than its electronic conductivity. The ionic conductivity of LSCF increases with increasing temperature (600-900°C), and the electronic conductivity decreases with increasing temperature (600-900°C). Measurements were also made on a foil of silver to investigate oxygen transport through it. From this, oxygen ion conductivity through silver was estimated.

scholarly journals Mixed Ionic-Electronic Conductors Based on PEDOT:PolyDADMA and Organic Ionic Plastic Crystals

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1981
Author(s):  
Rafael Del Olmo ◽  
Nerea Casado ◽  
Jorge L. Olmedo-Martínez ◽  
Xiaoen Wang ◽  
Maria Forsyth
Keyword(s):  
Energy Storage ◽  
Ionic Conductivity ◽  
Electronic Devices ◽  
Electronic Conductivity ◽  
Ionic Conductivities ◽  
New Materials ◽  
Plastic Crystals ◽  
Energy Storage Applications ◽  
Mixed Ionic Electronic Conductors ◽  
Electronic Conductors

Mixed ionic-electronic conductors, such as poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) are postulated to be the next generation materials in energy storage and electronic devices. Although many studies have aimed to enhance the electronic conductivity and mechanical properties of these materials, there has been little focus on ionic conductivity. In this work, blends based on PEDOT stabilized by the polyelectrolyte poly(diallyldimethylammonium) (PolyDADMA X) are reported, where the X anion is either chloride (Cl), bis(fluorosulfonyl)imide (FSI), bis(trifluoromethylsulfonyl)imide (TFSI), triflate (CF3SO3) or tosylate (Tos). Electronic conductivity values of 0.6 S cm−1 were achieved in films of PEDOT:PolyDADMA FSI (without any post-treatment), with an ionic conductivity of 5 × 10−6 S cm−1 at 70 °C. Organic ionic plastic crystals (OIPCs) based on the cation N-ethyl-N-methylpyrrolidinium (C2mpyr+) with similar anions were added to synergistically enhance both electronic and ionic conductivities. PEDOT:PolyDADMA X / [C2mpyr][X] composites (80/20 wt%) resulted in higher ionic conductivity values (e.g., 2 × 10−5 S cm−1 at 70 °C for PEDOT:PolyDADMA FSI/[C2mpyr][FSI]) and improved electrochemical performance versus the neat PEDOT:PolyDADMA X with no OIPC. Herein, new materials are presented and discussed including new PEDOT:PolyDADMA and organic ionic plastic crystal blends highlighting their promising properties for energy storage applications.

Preparation and characterization of compounds in the BaBiO3–Ba(Ce1-xGdx)O3-x/2 system

1999 ◽  
Vol 14 (1) ◽  
pp. 124-131 ◽  
Author(s):  
R. Mukundan ◽  
P. K. Davies ◽  
W. L. Worrell
Keyword(s):  
Ionic Conductivity ◽  
Elevated Temperatures ◽  
Electronic Conductivity ◽  
Mixed Valence ◽  
Type Model ◽  
Pseudobinary System ◽  
Conducting Oxides ◽  
Oxygen Ion ◽  
Reducing Conditions ◽  
Electronic Conductivities

The structure, nonstoichiometry, and electrical conductivity of compositions in the BaBiO3– Ba(Ce1-xGdx)O3-x/2 system have been investigated in an attempt to prepare new mixed (ionic-electronic) conducting oxides. The substitution of Bi into Ba(Ce1-xGdx)O3-x/2 decreases the concentration of oxygen-ion vacancies, and the effective negative charge of the Gd dopant is compensated by the mixed valence of Bi (3+, 5+). For low Bi contents a decrease in ionic conductivity decreases the overall conductivity; however, higher levels of Bi introduce significant electronic conductivity, and for Ba(Bi0.5Ce0.5)O3, σtotal ≈ 1 S/cm at 800 °C in air. Compositions in the Ba(Bi0.5Ce0.5-xGdx)O3 pseudobinary system undergo a B-cation order-disorder transformation at 1300–1350 °C for x = 0.5 and at ≈1250 °C for x = 0.4; all other compositions retain a disordered B-site arrangement. While these disordered perovskites exhibit oxygen nonstoichiometry under reducing conditions at elevated temperatures, with the extent of reduction decreasing with increasing Gd content, their ordered counterparts remain close to stoichiometry. The electronic conductivities of this pseudobinary could be fitted to a “band-type” model, and, despite the presence of oxygen vacancies for the lower values of x, no significant ionic conductivity was observed.

Experimental Study on Electrical Conductivity of FexO-CaO-SiO2-Al2O3 System at Various Oxygen Potentials

2018 ◽  
Vol 37 (2) ◽  
pp. 121-125 ◽  
Author(s):  
Yan–Xiang Liu ◽  
Jun–Hao Liu ◽  
Guo–Hua Zhang ◽  
Jian–Liang Zhang ◽  
Kuo–Chih Chou
Keyword(s):  
Electrical Conductivity ◽  
Ionic Conductivity ◽  
Oxygen Potential ◽  
Electronic Conductivity ◽  
Transference Number ◽  
Free Oxygen ◽  
Total Electrical Conductivity ◽  
Oxygen Ion ◽  
Conductivity Increase ◽  
Temperature Dependences

AbstractThe electrical conductivity of FexO-CaO-SiO2-Al2O3 slags was measured by a four terminal method. The results show that the temperature dependences of total, electronic and ionic conductivity for different compositions obey the Arrhenius law and all of them increase as increasing the temperature. For all the studied slags, as increasing CO/CO2 ratio which is used to controlled the oxygen potential, both the total electrical conductivity and electronic conductivity increase, but the ionic conductivity decreases. It was also found that the electronic transference number exhibits a strong correlation with oxygen potential, but is independent of temperature. Under the condition of constant FexO content, the higher the basicity of slags is, the higher the total electrical conductivity and ionic/electronic conductivity will be, which is resulted from the increase of free oxygen ion.

Processing and Electrochemical Properties of Mixed Conducting Lat-xAxCo1-yFeyO3-δ (A=Sr, Ca)

1994 ◽  
Vol 369 ◽  
Author(s):  
W. J. Weber ◽  
J. W. Stevenson ◽  
T. R. Armstrong ◽  
L. R. Pederson ◽  
J. J. Kingsley
Keyword(s):  
Perovskite Structure ◽  
Applied Field ◽  
Synthesis Method ◽  
Oxygen Ion Conductivity ◽  
Oxygen Ion ◽  
Electrical Conductivities ◽  
Permeation Studies ◽  
Thermogravimetric Studies ◽  
Increasing Temperature ◽  
Significant Flux

AbstractPowder compositions in the series Lat-xAxCo1-yFeyO3-δ (A=Sr, Ca) have been prepared by a combustion synthesis method. Sintering of pressed powders produced high-density test specimens with the perovskite structure. The specimens exhibited high electrical conductivities with appreciable oxygen-ion conductivity that increased with Co content for the compositions studied. Oxygen permeation studies showed a significant flux of oxygen that increased with temperature for specimens in a P(O2) gradient with no applied field. Thermogravimetric studies of the Lat-xCo0.2Fe0.8O3-δ system indicated a reversible mass loss with increasing temperature that increased with Sr content.

Coordination polymer-based conductive materials: ionic conductivity vs. electronic conductivity

2019 ◽  
Vol 7 (42) ◽  
pp. 24059-24091 ◽  
Author(s):  
Hai-Ning Wang ◽  
Xing Meng ◽  
Long-Zhang Dong ◽  
Yifa Chen ◽  
Shun-Li Li ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Ionic Conductivity ◽  
Coordination Polymer ◽  
Coordination Polymers ◽  
Electronic Conductivity ◽  
Structural Factors ◽  
Conductive Materials ◽  
Recent Developments

This review summarizes recent developments of coordination polymers and their derivatives for ionic and electrical conductivity with the discussion about synthetic strategies and possible mechanisms to identify the key structural factors.

Structural Characterization and Ionic Conductivity of Metastable Gd2(Ti0.65Zr0.35)2O7 Powders Prepared by Mechanical Milling

2006 ◽  
Vol 972 ◽  
Author(s):  
Antonio F. Fuentes ◽  
Karla J. Moreno ◽  
Jacobo Santamaria ◽  
Carlos Leon ◽  
Ulises Amador
Keyword(s):  
Ionic Conductivity ◽  
Mechanical Milling ◽  
Sintering Temperature ◽  
Ion Dynamics ◽  
Conductivity Relaxation ◽  
Electrical Conductivity Relaxation ◽  
Ion Interactions ◽  
Oxygen Ion ◽  
Fluorite Type ◽  
Powder Phase

AbstractWe analyze in this work the influence of ordering on the oxygen ion dynamics in the ionic conductor Gd2(Ti0.65Zr0.35)2O7, prepared by mechanical milling. As-prepared powder phase presents a metastable anion deficient fluorite-type of structure below 800°C becoming a disordered pyrochlore above this temperature. Such phase transformation implies a significant increase in the ionic conductivity of this material as a result of a systematic decrease in the activation energy for the dc conductivity, from 1.23 to 0.78 eV. Electrical conductivity relaxation is well described by the Kohlrausch-Williams-Watts (KWW) stretched exponential function with the fractional exponent n decreasing systematically with increasing sintering temperature (increasing ordering) as a result of decreasing ion-ion interactions in better ordered samples.

Extended D.C. Electrical Transport Measurements on the Mixed Conductor Cu3Cs2

1997 ◽  
Vol 500 ◽  
Author(s):  
P. K. Lemaire ◽  
J. Benoit ◽  
R. Speel
Keyword(s):  
Ionic Conductivity ◽  
Electrical Transport ◽  
Electronic Conductivity ◽  
Ionic Transport ◽  
Mixed Conductor ◽  
Chemical Diffusion Coefficient ◽  
Mixed Conductors ◽  
Voltage Versus ◽  
Temperature Range ◽  
Transport Measurements

ABSTRACTD.C. electrical transport measurements have been done over the temperature range 200 K. to 450 K on the mixed conductor Cu3.0CS2 This work extends the original work done on CuxCS2 over the temperature range 260 K to 350 K. Above 220 K, the voltage versus time curves follow the Yokota model for mixed conductors. Below 220K, the voltage versus time curves were practically constant, suggesting very little ionic transport below this temperature, and an electronic conductivity of the order of 10−5 (Ω cm)−1 at 200 K. At ambient temperatures, the ionic conductivity and electronic conductivity were both of the order of 10−3 (Ω cm)−1, and the chemical diffusion coefficient found to be of the order of 10−6 cm2s−1, in agreement with earlier work on Cu3CS2. Above 220 K, the ionic conductivity versus temperature plots were of the Arrhenius form with an activation energy of about 0.36 eV. The jump time and residence time were estimated to be of the order of 10−12s and 10−6s respectively, confirming hopping as the mode of ionic transport. The electronic conductivity versus temperature plot confirmed thermal activation as the mode of electronic transport. The results suggest CuxCS2 to be very stable and the Yokota model, with very little modification, to be very reliable for the analysis of these mixed conductors.

Intrinsic Fast Oxygen Ionic Conductivity in the Gd2(ZrxTil−.)2O7, and Y2 (ZrxTil−x,)2O7, Pyrochlore Systems

1988 ◽  
Vol 135 ◽  
Author(s):  
P.K. Moon ◽  
H.L. Tuller
Keyword(s):  
Solid Solution ◽  
Ionic Conductivity ◽  
Oxygen Vacancy ◽  
Intrinsic Disorder ◽  
Structural Disorder ◽  
The Other ◽  
Oxygen Ion Conductivity ◽  
Oxygen Ion ◽  
O 24 ◽  
The Relationship

AbstractThe pyrochlore solid solution Gd2(Zrx Til−x)2O7, was found to be an attractive system for investigating the relationship between composition, structural disorder and ionic conductivity. Both cation and anion order parameters were found to decrease systematically with increasing substitution of Zr for Ti leading ultimately to intrinsic fast oxygen ion conductivity in the solid solution. The degree of intrinsic disorder was determined quantitatively from doping experiments and was found to be equal to l.0×lO39 exp(-O.24±0.03eV/kT)cm−6sfor x = 0.3 and substantially larger for higher values of x. Oxygen vacancy mobilities, on the other hand, were found to be relatively independent of x with values of μv, = 0.15exp(-0.78 ± 0.02 eV/kT)cm2V−1s−1. These, and more recent results, on Y2 (ZrxTil−x)2O7, are discussed in the context of the similarities between the pyrochlore and fluorite phases.

scholarly journals Analysis of Long-Range Interaction in Lithium-Ion Battery Electrodes

2016 ◽  
Vol 13 (3) ◽  
Author(s):  
Aashutosh Mistry ◽  
Daniel Juarez-Robles ◽  
Malcolm Stein ◽  
Kandler Smith ◽  
Partha P. Mukherjee
Keyword(s):  
Lithium Ion Battery ◽  
Mesoscale Model ◽  
Electronic Conductivity ◽  
Active Material ◽  
Lithium Ion ◽  
Microstructural Characterization ◽  
Range Interaction ◽  
Electron Conduction ◽  
Conductive Additive ◽  
And Performance

The lithium-ion battery (LIB) electrode represents a complex porous composite, consisting of multiple phases including active material (AM), conductive additive, and polymeric binder. This study proposes a mesoscale model to probe the effects of the cathode composition, e.g., the ratio of active material, conductive additive, and binder content, on the electrochemical properties and performance. The results reveal a complex nonmonotonic behavior in the effective electrical conductivity as the amount of conductive additive is increased. Insufficient electronic conductivity of the electrode limits the cell operation to lower currents. Once sufficient electron conduction (i.e., percolation) is achieved, the rate performance can be a strong function of ion-blockage effect and pore phase transport resistance. Even for the same porosity, different arrangements of the solid phases may lead to notable difference in the cell performance, which highlights the need for accurate microstructural characterization and composite electrode preparation strategies.

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