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62. Influence of surfactant on the structural, morphological and optical properties of SrWO4: Insights through electron density distribution analysis.

Author

Balu, Santhanam, Sivaganesh, D, Saravanakumar, S, Sivakumar, V, Kim, Ji-Man, Kannan, Padmanathan Karthick, and Ganesh, V

Subjects
ELECTRON density, ELECTRON distribution, OPTICAL properties, SURFACE active agents, X-ray powder diffraction
Abstract

Scheelite-type surfactant-assisted SrWO4 was prepared via a simple co-precipitation method. The effect of various surfactants such as hexamethylenetetramine, polyvinylpyrrolidone, and sodium dodecyl sulphate, on the structural, morphological and photoluminescence (PL) properties of SrWO4 was investigated. Powder X-ray diffraction and the Rietveld profile refinement technique confirmed the tetragonal structure of all the as-synthesized SrWO4 materials. Among the three surfactants, particles with spherical morphology were observed for SDS-assisted SrWO4. Surfactant-assisted SrWO4 exhibited bluish-green emission around 500 nm, ascribed to the presence of WO 4 2 - luminescence centre at 284 nm excitation, and the PL emission intensity significantly increased in the presence of surfactant. Electron density distribution analysis of a single unit cell for all the prepared materials was investigated, and correlated with the PL results. [ABSTRACT FROM AUTHOR]

Published
2023
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63. Operando small‐angle x‐ray scattering for battery research.

Author

Lee, Jaeik, Park, Hyeonji, Kim, Hansol, Kim, Taeyeob, Jin, Minshi, Kim, Taewhan, and Kim, Ji Man

Subjects
SMALL-angle X-ray scattering, SYNCHROTRON radiation, STORAGE batteries, SOLID electrolytes, ELECTRON density, ELECTRON microscopy, IONIC conductivity
Abstract

With the rapid growth of secondary batteries used in various industries, methods for analyzing battery elements such as electrodes and electrolytes have also improved. In addition, as the utility of nano‐scaled electrode materials have attracted greater attention, it has become increasingly clear that conventional electrochemical analytic methods have limitations. Consequently, electron microscopy and even synchrotron x‐ray radiation techniques have been adopted and are now widely used. Among several advanced analytical techniques, synchrotron radiation‐based operando small‐angle x‐ray scattering (SAXS) enables real‐time analysis of changes in the ordering of nanostructures and in the electron densities of electrodes and solid electrolytes during electrochemical reactions. In this review, the principle and applications of operando SAXS are briefly introduced, to help in understanding the complex nanostructural behaviors of battery components used in secondary batteries, and furthermore, it is hoped to contribute to innovative materials design. [ABSTRACT FROM AUTHOR]

Published
2023
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64. Review on Improving the Performance of SiOxAnodes for a Lithium-Ion Battery through Insertion of Heteroatoms: State of the Art and Outlook

Author

Kim, Taeyeob, Li, Hai, Gervasone, Rafael, Kim, Ji Man, and Lee, Jin Yong

Abstract

Anode materials for Li-ion batteries have attracted significant research interest owing to the growing demand for efficient and cost-effective energy storage systems. Among the various anode materials being studied, silicon-based anodes have garnered considerable attention as a result of their potential to overcome many of the limitations associated with graphite anodes. However, silicon-based anodes undergo high volumetric expansion during cycling, which results in anode failure. In contrast, silicon-oxide-based (SiOx) materials exhibit limited volumetric expansion, making them viable candidates as anode materials in lithium-ion batteries. Despite this, there remain several challenges associated with SiOxanodes, including volumetric expansion (160–200%), poor capacity retention, and low initial coulombic efficiency. To address these issues, the incorporation of heteroatoms into SiOxanodes has been proposed as a promising strategy. In this review, we aim to provide an overview of the current state of research on SiOxanodes, including experiments and theoretical calculations, with a focus on the insertion of heteroatoms to improve the anode performance. In particular, we examine the effects of heteroatom incorporation on the anode conductivity, lithium diffusion, durability, and initial coulombic efficiency. In addition, we present a design strategy for the insertion of heteroatoms into the SiOxanodes. This review aims to provide a comprehensive understanding of the role of heteroatoms in SiOxanodes and highlight the potential for further research in this area.

Published
2023
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