Dependence of the lithium ionic conductivity on the B-siteion substitution in $(Li_{0.5}La_{0.5})Ti_{1-x}M_xO_3$

Kim, Jin-Gyun,Kim, Ho-Gi The Korean Institute of Electrical and Electronic 1998 전기전자재료 Vol.11 No.11

The dependence of the ionic conductivity on the B-site ion substitution in (Li0.5La0.5)Ti1-xMxO3 (M=Sn, Zr, Mn, Ge) system has been studied. Same valence state and various electronic configuration and ionic radius of Sn4+, Zr4+, Mn4+ and Ge4+(4d10(0.69$\AA$), 4p6(0.72$\AA$), 3d10(0.54$\AA$) and 3d3(0.54$\AA$), respectively) induced the various crystallographic variaton with substitutions. So it was possibleto investigate the crystallographic factor which influence the ionic conduction by observing the dependence of the conductivity on the crystallographic factor which influence the ionic conduction by observing the dependence of the conductivity on the crystallographic variations. We found that the conductivity increased with decreasing the radii of B-site ions or vice versa and octahedron distortion disturb the ion conduction. The reason for this reciprocal proportion of conductivity on the radius of B-site ions has been examined on the base of the interatomic bond strength change due to the cation substitutions. The results were good in agreement with the experimental results. Therefore it could be concluded that the interatomic bond strength change due to the cation substitutions may be the one of major factors influencing the lithium ion conductivity in perovskite(Li0.5La0.5) TiO3system.

The type of solvate ionic liquids on Ionic conductivity and Thermal property of Epoxy-based Polymer Electrolytes

송연화,최우혁 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

For next-generation energy storage devices, mechanical robust solid polymer electrolytes (SPEs) have attracted widespread attention due to their good processability, low cost, and dimensional stability. However, they are generally appeared a trade-off characteristic between mechanical property and ionic conductivity. Herein, the cross-linked epoxy-based SPEs containing Li salt (LiTFSI) with glymes (G3 or G4) and Ionic liquid (IL), using the ring-opening polymerization. The glymes are chosen to dissociate the Li ion from LiTFSI salt, and the IL is selected to enhance ionic conductivity. Furthermore, the epoxy resin can provide high mechanical and thermal properties. The effect of ionic liquid types on mechanical and thermal properties, ionic conductivity, and morphology characterized by using DMA, DSC, TGA, dielectric spectroscopy, and Fe-SEM, respectively.

Ionic Liquid of a Gold Nanocluster: A Versatile Matrix for Electrochemical Biosensors

Kwak, Kyuju,Kumar, S. Senthil,Pyo, Kyunglim,Lee, Dongil American Chemical Society 2014 ACS NANO Vol.8 No.1

<P>Ionic liquids are room-temperature molten salts that are increasingly used in electrochemical devices, such as batteries, fuel cells, and sensors, where their intrinsic ionic conductivity is exploited. Here we demonstrate that combining anionic, redox-active Au<SUB>25</SUB> clusters with imidazolium cations leads to a stable ionic liquid possessing both ionic and electronic conductivity. The Au<SUB>25</SUB> ionic liquid was found to act as a versatile matrix for amperometric enzyme biosensors toward the detection of glucose. Enzyme electrodes prepared by incorporating glucose oxidase in the Au<SUB>25</SUB> ionic liquid show high electrocatalytic activity and substrate affinity. Au<SUB>25</SUB> clusters in the electrode were found to act as effective redox mediators as well as electronic conductors determining the detection sensitivity. With the unique electrochemical properties and almost unlimited structural tunability, the ionic liquids of quantum-sized gold clusters may serve as versatile matrices for a variety of electrochemical biosensors.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2014/ancac3.2014.8.issue-1/nn4053217/production/images/medium/nn-2013-053217_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn4053217'>ACS Electronic Supporting Info</A></P>

Ionic conductivity of polyelectrolyte based on ionic liquids

E.H. Chaa,S.A.Lim 호서대학교 기초과학연구소 2008 기초과학연구 논문집 Vol.16 No.1

Novel lithium polyelectrolyte based on ionic liquids have been prepared and characterized of their properties. Ionic conductivity, glass transition temperature and viscosity and thermal properties of gel polyelectrolytes which were composed of poly (lithium 2-acrylamido-2-methyl propanesulfonate) based on-ethyl-3-methylimidazolium tricyanomethanide (emlmTCM) and N,N-dimethyl-N-propyl—N-butyl ammonium tricyanomethanide (N1134 TCM) and N,N-dimethyl-N -propyl—N-butyl ammonium dicyanamide (N1134DCA) were measured. The ionic conductivity of this polyelectrolyte with ionic liquid (emlmTCM) exhibits higher conductivity (1.28*10-3 S/cm) than that of polyelectrolyte with N1134 TCM (6.3*10-4S/cm) and Nn34DCA(6.0*10-4 S/cm). Because of using the polymerizable group is seemed to maintain high flexibility of imidazolium cation effectively to exhibit the higher conductivity. The viscosity of emlmTCM (.19.56cP) is lower than that of N1134 TCM (28.61cP) and N 1134 DCA (28.72cP). Lower viscosity and dissociation of lithium cations from the polymer chains exhibit the higher conductivity.

Electrochemical properties for ionic liquid/polymer electrolyte systems

Park, Nam Ku,Bae, Young Chan Wiley Subscription Services, Inc., A Wiley Company 2010 Journal of polymer science. Part B, Polymer physic Vol.48 No.2

<P>The ionic liquid (1-ethyl-3-methylimidazolium hexafluorouphophate) ([emim][PF<SUB>6</SUB>]) with different molecular weights of poly(ethylene oxide) (PEO) (MW = 4600; 10,000; 14,000; 20,000; 35,000, and 100,000) has been characterized at various temperatures and compositions using phase behaviors and ionic conductivity. A molecular thermodynamic model based on a combination of the previous theory (BH model) by Chang et al., a nonrandomness theory (NR model), and the Pitzer-Debye-Hückel theory modified by Guggenheim (PDH model) considered not only short-range specific interactions between the polymer and a cation of the ionic liquid (IL), but also long-range electrostatic forces between anions and cations within the IL. We have derived a new melting point depression theory based on this BH-NR-PDH model. We also established an ionic conductivity model, based on the Nernst-Einstein equation, in which the diffusion coefficient is derived from the BH-NR-PDH model. The proposed model takes into account that the mobility of cations in the IL and the motions of the polymer host by expressing the effective chemical potential as the sum of the chemical potentials of the polymer and the IL. To describe the segmental motion of the cation and polymer chain, the effective coordinated unit parameter is introduced. The derived coordinated unit parameter for each state is used to determine the ionic conductivities of the given systems. Quantitative results from the proposed model are in good agreement with experimental data. The results indicate that the molecular weight of the polymer and the surrounding temperature play important roles in determining eutectic points and ionic conductivities of the given systems. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 212–219, 2010</P>

Improvement of Mechanical and Electrical Properties of Poly(ethylene glycol) and Cyanoresin Based Polymer Electrolytes

Oh Kyung-Wha,Choi Ji-Hyoung,Kim Seong-Hun The Korean Fiber Society 2006 Fibers and polymers Vol.7 No.2

Ionic conductivity and mechanical properties of a mixed polymer matrix consisting of poly(ethylene glycol) (PEG) and cyanoresin type M (CRM) with various lithium salts and plasticizer were examined. The CRM used was a copolymer of cyanoethyl pullulan and cyanoethyl poly(vinyl alcohol) with a molar ratio of 1:1, mixed plasticizer was ethylene carbonate (EC) and propylene carbonate (PC) at a volume ratio of 1:1. The conductive behavior of polymer electrolytes in the temperature range of $298{\sim}338\;K$ was investigated. The $PEG/LiClO_4$ complexes exhibited the highest ionic conductivity of ${\sim}10^{-5}S/cm$ at $25^{\circ}C$ with the salt concentration of 1.5 M. In addition, the plasticized $PEG/LiClO_4$ complexes exhibited improvement of ionic conductivity. However, their complexes showed decreased mechanical properties. The improvement of ionic conductivity and mechanical properties could be obtained from the polymer electrolytes by using CRM. The highest ionic conductivity of PEG/CRM/$LiClO_4$/(EC-PC) was $5.33{\time}10^{-4}S/cm$ at $25^{\circ}C$.

An ionic conductivity characterization of gel polymer electrolyte containing porous-microcapsule as filler

한아람,오수경,김상진,김현경 한국공업화학회 2014 한국공업화학회 연구논문 초록집 Vol.2014 No.1

The polymer electrolytes are faced with poor conductivity and electrochemical stability despite their outstanding properties such as mechanical property, processability and improved safety. In this study, the gel polymer electrolyte containing porous-microcapsule was suggested to enhance an ionic conductivity. We synthesized porous-microcapsule and used as filler for PVdF-HFP gel polymer electrolyte system swollen with 1M LiClO₄ in EC: DMC (3:7). From the results obtained, increasing the contents of porous-microcapsule up to 20wt%, the porosity of film was also increased and swelling ratio of film can be improved. It was closely related with an ionic conductivity, it was proven that the nonfillers PVdF-HFP gel polymer electrolyte system showed the conductivity value of 1.57×10^-3 S/cm and the ionic conductivity is further enhanced to 6.21×10^-3 S/cm with the addition of 20 wt% of porous-microcapsule.

Enhancement of Mechanical Stability and Ionic Conductivity of Chitosan-based Solid Polymer Electrolytes Using Silver Nanowires as Fillers

김재석,임종국,박진성 대한화학회 2019 Bulletin of the Korean Chemical Society Vol.40 No.9

With the emergence of wearable devices and internet of things, it is expected that small flat, and flexible electrochemical devices will be required for these applications. One of the prerequisites for these devices to be applied to such fields is the development of solid polymer electrolytes with high ionic conductivity. Because most solid polymer electrolytes have low ionic conductivity, small organic molecules have been used as plasticizers to increase their ionic conductivity. Since these plasticizers can increase amorphous regions that play the role of ion channels in polymer, their ionic conductivity increases; however, their mechanical stability decreases inversely. Conventionally, to overcome this drawback, inert nanoparticles are added into solid polymer electrolytes as fillers. Herein, we show that 1-dimensional silver nanowires can increase the mechanical stability of chitosan-based solid polymer electrolytes as well as their ionic conductivity more than nanospheres can, and discuss a plausible mechanism for such an enhancement.

From structure to function: Harnessing the ionic conductivity of covalent organic frameworks

Liu Cong‐Xue,황수민,우혜린,이은성,박선아 대한화학회 2024 Bulletin of the Korean Chemical Society Vol.45 No.4

Rapid advancements in energy storage technology, driven by a growing demand for energy storage devices, underscore the crucial need to comprehend ionic conduction behavior. Consequently, intensive research on high‐performance ionic conductors becomes imperative. Covalent organic frameworks (COFs) have emerged as invaluable materials in the realm of solid‐state or quasi‐solid‐state ion‐conduction, leveraging their unique properties such as significant porosity, tunability, and robust physicochemical durability. These distinctive attributes position COFs as promising candidates for the development of electrodes, electrolytes, and separator materials characterized by high capacities, rapid ion transport, and electrochemical stability. This review provides insights into COFs as ionic conductors, discusses recent advancements in COF‐based energy storage devices, and explores the influence of structural functionalization, pore size engineering, and dimensional regulation on ionic conduction. Moreover, the review aims to deepen understanding and pave the way for future advancements in the utilization of COFs within energy storage technologies. Rapid advancements in energy storage technology, driven by a growing demand for energy storage devices, underscore the crucial need to comprehend ionic conduction behavior. Consequently, intensive research on high-performance ionic conductors becomes imperative. Covalent organic frameworks (COFs) have emerged as invaluable materials in the realm of solid-state or quasi-solid-state ion-conduction, leveraging their unique properties such as significant porosity, tunability, and robust physicochemical durability. These distinctive attributes position COFs as promising candidates for the development of electrodes, electrolytes, and separator materials characterized by high capacities, rapid ion transport, and electrochemical stability. This review provides insights into COFs as ionic conductors, discusses recent advancements in COF-based energy storage devices, and explores the influence of structural functionalization, pore size engineering, and dimensional regulation on ionic conduction. Moreover, the review aims to deepen understanding and pave the way for future advancements in the utilization of COFs within energy storage technologies.

LATP 내 비정상 입자성장이 이온 전도도에 미치는 영향

최형익,한윤수 한국분말재료학회(구 한국분말야금학회) 2024 한국분말재료학회지 (KPMI) Vol.31 No.1

This study investigates the effect of the microstructure of Li1.3Al0.3Ti1.7(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 950oC 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 900oC 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.