• Corrosion Science and Technology
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• v.22 no.4
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• pp.287-296
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• 2023

Li-ion batteries have been gaining increasing importance, driven by the growing utilization of renewable energy and the expansion of electric vehicles. To meet market demands, it is essential to ensure high energy density and battery safety. All-solid-state batteries (ASSBs) have attracted significant attention as a potential solution. Among the advantages, they operate with an ion-conductive solid electrolyte instead of a liquid electrolyte therefore significantly reducing the risk of fire. In addition, by using high-capacity alternative electrode materials, ASSBs offer a promising opportunity to enhance energy density, making them highly desirable in the automotive and secondary battery industries. In ASSBs, Li metal can be used as the anode, providing a high theoretical capacity (3860 mAh/g). However, challenges related to the high interfacial resistance between Li metal and solid electrolytes and those concerning material degradation during charge-discharge cycles need to be addressed for the successful commercialization of ASSBs. This review introduces and discusses the interfacial reactions between Li metal and solid electrolytes, along with research cases aiming to improve these interactions. Additionally, future development directions in this field are explored.

• Journal of the Korean Ceramic Society
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• v.51 no.4
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• pp.260-264
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• 2014

We developed a novel double dopant bismuth oxide system with Tb and W. When Tb was doped as a single dopant, a Tb dopant concentration more than 20 mol% was required to stabilize bismuth oxides with a high conductivity cubic structure. High temperature XRD analysis of 25 mol% Tb-doped bismuth oxide (25TSB) confirmed that the cubic structure of 25TSB was retained from room temperature to $700^{\circ}C$ with increase in the lattice parameter. On the other hand, we achieved the stabilization of high temperature cubic phase with a total dopant concentration as low as ~12 mol% with 8 mol% Tb and 4 mol% W double dopants (8T4WSB). Moreover, the measured ionic conductivity of 10T5WSB was much higher than 25TSB, thus demonstrating the feasibility of the double dopant strategy to develop stabilized bismuth oxide systems with higher oxygen ion conductivity for the application of SOFC electrolytes at reduced temperature. In addition, we investigated the long-term stability of TSB and TWSB electrolytes.

• Korean Journal of Materials Research
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• v.32 no.10
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• pp.429-434
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• 2022

There is ongoing research to develop lithium ion batteries as sustainable energy sources. Because of safety problems, solid state batteries, where electrolytes are replaced with solids, are attracting attention. Sulfide electrolytes, with a high ion conductivity of 10^-3 S/cm or more, have the highest potential performance, but the price of the main materials is high. This study investigated lithium hydride materials, which offer economic advantages and low density. To analyze the change in ion conductivity in polymer electrolyte composites, PVDF, a representative polymer substance was used at a certain mass ratio. XRD, SEM, and BET were performed for metallurgical analyses of the materials, and ion conductivity was calculated through the EIS method. In addition, thermal conductivity was measured to analyze thermal stability, which is a major parameter of lithium ion batteries. As a result, the ion conductivity of LiH was found to be 10^-6 S/cm, and the ion conductivity further decreased as the PVDF ratio increased when the composite was formed.

• Journal of Powder Materials
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• v.30 no.2
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• pp.107-115
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• 2023

Li_1.3Al_0.3Ti_1.7(PO₄)₃(LATP) is considered a promising material for all-solid-state lithium batteries owing to its high moisture stability, wide potential window (~6 V), and relatively high ion conductivity (10^-3-10^-4 S/cm). Solid electrolytes based on LATP are manufactured via sintering, using LATP powder as the starting material. The properties of the starting materials depend on the synthesis conditions, which affect the microstructure and ionic conductivity of the solid electrolytes. In this study, we synthesize the LATP powder using sol-gel and co-precipitation methods and characterize the physical properties of powder, such as size, shape, and crystallinity. In addition, we have prepared a disc-shaped LATP solid electrolyte using LATP powder as the starting material. In addition, X-ray diffraction, scanning electron microscopy, and electrochemical impedance spectroscopic measurements are conducted to analyze the grain size, microstructures, and ion conduction properties. These results indicate that the synthesis conditions of the powder are a crucial factor in creating microstructures and affecting the conduction properties of lithium ions in solid electrolytes.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.5
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• pp.523-523
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• 2003

The change of interactions of anionic surfactants, sodium dodecyl sulfate(SDS) and sodium tetradecyl sulfate(575) in the presence of electrolytes, to the chitosan-based polyelectrolyte(sol＇n and gel phase) were studied. The chitosan gel used in this study were crosslinked with epichlorohydrin(ECH). Binding isotherms were determined by potentiometric technique using a surfactant ion selective solid-state electrode and the results were represented by using the sequence generating function(SGF) method. The results of binding isotherm were shown comparatively high cooperativity. The addition of electrolytes in the chitosan/SDS system resulted in a shift of the binding to higher free surfactant concentration because of screen effect by the electrolytes. Degree of binding of chitosan gel was higher than that of chitosan sol＇n. And also a conformational phase transition of the chitosan gel in the presence of electrolytes has been investigated.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.5
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• pp.524-532
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• 2003

The change of interactions of anionic surfactants, sodium dodecyl sulfate(SDS) and sodium tetradecyl sulfate(575) in the presence of electrolytes, to the chitosan-based polyelectrolyte(sol＇n and gel phase) were studied. The chitosan gel used in this study were crosslinked with epichlorohydrin(ECH). Binding isotherms were determined by potentiometric technique using a surfactant ion selective solid-state electrode and the results were represented by using the sequence generating function(SGF) method. The results of binding isotherm were shown comparatively high cooperativity. The addition of electrolytes in the chitosan/SDS system resulted in a shift of the binding to higher free surfactant concentration because of screen effect by the electrolytes. Degree of binding of chitosan gel was higher than that of chitosan sol＇n. And also a conformational phase transition of the chitosan gel in the presence of electrolytes has been investigated.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.24-27
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• 2009

Solid-state dye-sensitized solar cells (DSSCs) have been constructed employing supramolecular electrolytes with multiple hydrogen bonding. A supramolecule was facilely synthesized by one-pot reaction between the amines of methyl isocytosine (MIC) and the epoxy groups of poly(ethylene glycol diglycidyl ether) (PEGDGE) to produce quadruple hydrogen bonding units. Hydrogen bonding interactions and dissolution behavior of salt in supramolecular electrolytes are investigated. The ionic conductivity of the supramolecular electrolytes with ionic liquid, i.e. 1-methyl-3-propylimidazolium iodide (MPII) reaches $8.5{\times}10^{-5}$ S/cm at room temperature, which is higher than that with metal salt (KI). A worm-like morphology is observed in the FE-SEM micrographs of $TiO_2$ nanoporous layer, due to the connection of $TiO_2$ nanoparticles resulting from adequate coating by electrolytes. DSSCs employing the supramolecular electrolytes with MPII and KI exhibit an energy conversion efficiency of 2.5 % and 0.5 %, respectively, at 100 $mW/cm^2$, indicating the importance of the cation of salt. Solar cell performances were further improved up to 3.7 % upon introduction of poly(ethylene glycol dimethyl ether) (PEGDME) with 500 g/mol.

• Journal of Electrochemical Science and Technology
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• v.12 no.1
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• pp.126-136
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• 2021

The electrochemical performance of all-solid-state cells (ASSCs) based on sulfide electrolytes is critically affected by the undesirable interfacial reactions between oxide cathodes and sulfide electrolytes because of the high reactivity of sulfide electrolytes. Based on the concept that the interfacial reactions are highly dependent on the type of sulfide electrolyte, the electrochemical properties of the ASSCs prepared using three types of sulfide electrolytes were observed and compared. The Li2MoO4-LiI coating layer was also introduced to suppress the interfacial reactions. The cells using argyrodite electrolyte exhibited a higher capacity and Coulombic efficiency than the cells using 75Li2S-22P2S5-3Li2SO4 and Li7P3S11 electrolytes, indicating that the argyrodite electrolyte is less reactive with cathodes than other electrolytes. Moreover, the introduction of Li2MoO4-LiI coating on the cathode surface significantly enhanced the electrochemical performance of ASSCs because of the protection of coating layer. Pulverization of argyrodite electrolyte is also effective in increasing the capacity of cells because the smaller size of electrolyte particles improved the contact stability between the cathode and the sulfide electrolyte. The cyclic performance of cells was also enhanced by pulverized electrolyte, which is also associated with improved contact stability at the cathode/electrolyte. These results show that the introduction of Li2MoO4-LiI coating and the use of pulverized sulfide electrolyte can exhibit a synergic effect of suppressed interfacial reaction by the coating layer and improved contact stability owing to the small particle size of electrolyte.

• Corrosion Science and Technology
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• v.22 no.6
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• pp.466-477
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• 2023

The increasing demand for high-performance energy storage systems has highlighted the limitations of conventional Li-ion batteries (LIBs), particularly regarding safety and energy density. All-solid-state batteries (ASSBs) have emerged as a promising next-generation energy storage system, offering the potential to address these issues. By employing nonflammable solid electrolytes and utilizing high-capacity electrode materials, ASSBs have demonstrated improved safety and energy density. Automotive and energy storage industries, in particular, have recognized the significance of advancing ASSB technology. Although the use of Li metal as ASSB anode is promising due to its high theoretical capacity and the expectation that Li dendrites will not form in solid electrolytes, persistent problems with Li dendrite formation during cycling remain. Therefore, the exploration of novel high-performance anode materials for ASSBs is highly important. Recent research has focused extensively on alloy-based anodes for ASSBs, owing to their advantages of no dendrite formation and high-energy density. This study provides a comprehensive review of the latest advancements and challenges associated with alloy-based anodes for ASSBs.

• Transactions on Electrical and Electronic Materials
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• v.9 no.6
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• pp.227-230
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• 2008

Programmable Metallization Cell (PMC) Random Access Memory is based on the electrochemical growth and removal of electrical nanoscale pathways in thin films of solid electrolytes. In this study, we investigated the nature of thin films formed by the photo doping of copper ions into chalcogenide materials for use in programmable metallization cell devices. These devices rely on metal ions transport in the film so produced to create electrically programmable resistance states. The results imply that a Cu-rich phase separates owing to the reaction of Cu with free atoms from chalcogenide materials.