• Journal of the Korean Ceramic Society
• /
• v.33 no.6
• /
• pp.645-652
• /
• 1996

The ionic conductivity of NASICON (Na Super Ionic Conductor) solid electrolyte was simulated by using Monte Carlo Method (MCM)based on a hopping model. We assumed that the conduction path of Na ions is Na1→mid-Na→Na2 where the mid-Na sites are shallow potential sites to induce 'a breathing-like movement' of Na ions in the NASICON framework. The minimum of charge correlation factor Fc and the maximum of appeared at nearby x=2.0 The occupancy of mid-Na site affected the depth of potential barrier and the conduc-tivity of the NASICON. At above x=0.3 ln σT vs. 1/T* plots have been shown Arrhenius behavior but in (VWfc)vs. 1/T* have been shown the Arrhenius type tendency at x=1 MCM results accorded with the experi-mental procedure. The role of mid-Na on Na+ ion conduction could be explained by an additional driving force and a breating-like movement model for motions of Na+ ions in the NASICON framework. As we couldn't clearly remarked the model which is the better it seems reasonable to conclude that these hypothesies are suitable to explain the FIC behavior at NASICON.

• Journal of Powder Materials
• /
• v.31 no.1
• /
• pp.23-29
• /
• 2024

This study investigates the effect of the microstructure of Li_1.3Al_0.3Ti_1.7(PO₄)₃ (LATP), a solid electrolyte, on its ionic conductivity. Solid electrolytes, a key component in electrochemical energy storage devices such as batteries, differ from traditional liquid electrolytes by utilizing solid-state ionic conductors. LATP, characterized by its NASICON structure, facilitates rapid lithium-ion movement and exhibits relatively high ionic conductivity, chemical stability, and good electrochemical compatibility. In this study, the microstructure and ionic conductivity of LATP specimens sintered at 850, 900, and 950℃ for various sintering times are analyzed. The results indicate that the changes in the microstructure due to sintering temperature and time significantly affect ionic conductivity. Notably, the specimens sintered at 900℃ for 30 min exhibit high ionic conductivity. This study presents a method to optimize the ionic conductivity of LATP. Additionally, it underscores the need for a deeper understanding of the Li-ion diffusion mechanism and quantitative microstructure analysis.

• Journal of the Korean Ceramic Society
• /
• v.33 no.4
• /
• pp.385-390
• /
• 1996

The electrical resistivity of the ceramic glaze coated on ceramic substrate plays an important role on the characteristics of the thick and thin film electrical circuits. In this study the effects of the various modifiers on the electrical resistivity were examined in SiO2-Al2O3-B2O3-RO-Na2O (RO=CaO , SrO, BaO, PbO) glass system. In alkali free glasses where divalent cations are responsible for electrical conduction the electrical conductivity of th glasses increased with the ionic size of divalent cations due to the decrease in the bond strength between oxyben and divalent cation. In Na2O containing glasses however where Na+ ion is responsible for electrical conduction the ionic conductivity decreased with the ionic size of divalent cations because the blocking effect of the cations on Na+ ion movement increased with larger divalent cations. Na+ ionic conduction also depended on the glass structure relaxation due to the corrdination number changes of B2O3 and Al2O3 which varied with the NaO2 content in the glass.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2017.05a
• /
• pp.96.1-96.1
• /
• 2017

This presentation introduces anodizing science of typical valve metals of Al, Mg and Ti, based on the ionic transport through the andic oxide films in various electrolyte compositions. Depending on the electrolyte composition, metal ions and anions can migrate through the andic oxide film without its dielectric breakdown when point defects are present within the anodic oxide films under high applied electric field. On the other hand, if anodic oxide films are broken by local joule heating due to ionic migration, metal ions and anions can migrate through the broken sites and meet together to form new anodic films, known as plasma electrolytic oxidation (PEO) treatment. In this presentation, basics of conventional anodizing and PEO methods are introduced in detail, based on the ionic migration and movement mechanism through anodic oxide films by point defects and by local dielectric breakdown of anodic oxide films.

• Proceedings of the KIEE Conference
• /
• 1996.07c
• /
• pp.1642-1644
• /
• 1996

Passivation must prevent ionic charge movement on the surface of the junction, thereby minimizing the junction leakage and maximizing the breakdown voltage of the devices. Borosilicate glasses are widely used as surface passivants for such silicon power devices as thyristors, transistor, and diodes. Since these 91asses are electrically stable at high temperatures and in high electric fields, they can readily be applied as a thick film, and they are resistant to humidity and have low ionic mobility. A deposition technique of glass film on the silicon surface by electrophoresis in which acetone is used as a suspension medium has been investigated. The purpose of this paper is to describe electrophoretic deposition method for glass passivation and characteristics of glass films which were compared using DTA, SEM, XRD, as a function of firing temperature.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1994.10a
• /
• pp.108-112
• /
• 1994

The paper describes the effects of magnetic field on the electrochemical polishing process in the view of ionic in the electrolyte. Theoretical background was suggested how magnetic field increases the material removal efficiency and surface finishing ability Magnetic field changes the jonic movement in the electrolyte from linear motion to curved or complex oscillating one, thus increases the electrolytic current density and, as the results, the finishing efficiency.

• Proceedings of the Korean Biophysical Society Conference
• /
• 1997.07a
• /
• pp.35-35
• /
• 1997

We model the voltage-gated cation channel on the basis of stochastic process by taking into account transmembrane movement of S4 group interacting electrostatically with permeant ions. It is assumed that the interaction between the ion and S4 group is repulsive harmonic force and the ionic motion is much faster than that of the S4 group.(omitted)

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2013.05a
• /
• pp.531-533
• /
• 2013

In this paper, to study the IPMC (Ionic exchange Polymer Metal Composite) material consisting of a sulfonic acid ion and fluoride combination of carbon with Nafion film greatly affected the electro-active polymer (Electro Active Polymer) characteristics and the presence of water and cationshave properties. Use or electrical energy into mechanical energy, mechanical energy, electrical energy, and can be utilized to its characteristics, depending on the water and cations in water varies greatly. Configure the device simulations in order to study the electrical properties of these IPMC. Stepper Motor using MCU and simulator designed for the electrical characterization due to the movement and to the implementation of the mechanical movement of ocean currents. In this study, configuration the IPMC and simulation device to the area of the IPMC to the efficient use of energy currents, frequency, salinity concentration, through the efficient use of the IPMC due to the bend angle of the electrical analysis and research methods we propose.

• Journal of Electrochemical Science and Technology
• /
• v.12 no.1
• /
• pp.1-20
• /
• 2021

In-depth knowledge of electrode processes is crucial for determining the electrochemical performance of lithium-ion batteries (LIBs). In particular, the conduction mechanisms of charged species in the electrodes, such as lithium ions (Li+) and electrons, are directly correlated with the performance of the battery because the overall reaction is dependent on the charge transport behavior in the electrodes. Therefore, it is necessary to understand the different electrochemical processes occurring in electrodes in order to elucidate the charge conduction phenomenon. Thus, it is essential to conduct fundamental studies on electrochemical processes to resolve the technical challenges and issues arising during the ionic and electronic conduction. Furthermore, it is also necessary to understand the transport of charged species as well as the predominant factors affecting their transport in electrodes. Based on such in-depth studies, potential approaches can be introduced to enhance the mobility of charged entities, thereby achieving superior battery performances. A clear understanding of the conduction mechanism inside electrodes can help overcome challenges associated with the rapid movement of charged species and provide a practical guideline for the development of advanced materials suitable for high-performance LIBs.

• Economic and Environmental Geology
• /
• v.45 no.5
• /
• pp.525-533
• /
• 2012

Snowmelt from seasonal snow covers can be significant in many environments of northern and alpine areas. Water flow and chemical transport resulting from snowmelt have been studied for an understanding of contributions to watersheds or catchments. A Mobile-Immobile water Model (MIM) was developed to describe the movement of ionic tracers through a snowpack by Lee et al. (2008a) and Lee et al. (2008b). To validate the model used in the studies, mass balance calculations of the model were conducted and comparisons were made between model results and analytical solutions in this work. Mass balance was calculated based on the fact that change in total mass within a snowpack with time is equal to sum of any change in the flux of water or ionic tracers into and out of the snowpack. Calculations of both water and ionic mass show almost perfect agreement between changes of two water and solute mass fluxes. Comparisons between model results and analytical solutions including wave velocity and effective saturation show almost perfect agreement.