https://scholar.korea.ac.kr/handle/2021.sw.korea/752 Wed, 01 Apr 2026 16:18:36 GMT 2026-04-01T16:18:36Z https://scholar.korea.ac.kr/handle/2021.sw.korea/94130 Title: Review on mechanisms and continuum models of multi-phase transport phenomena in porous structures of non-aqueous Li-Air batteries Authors: Yuan, Jinliang; Yu, Jong-Sung; Sunden, Bengt Abstract: During recent years intensive research activities involving both experimental and modeling approaches have appeared for different aspects of Lithium-air (Li-air) battery. Multi-phase transport phenomena including dissolved oxygen and lithium ions (Lit) in the liquid electrolyte, as well as electrons in the solid materials, are strongly coupled with the porous structures and various reactions, particularly the solid product grown in the porous cathode during battery discharge. Understanding the mechanisms of transport phenomena and accurate evaluation of effective transport properties are significant for improving the battery capacities and design, especially at high rate conditions. In this paper, the transport governing equations commonly used for macroscopic continuum models at porous-average level are outlined and highlighted, with a purpose to provide a general overview of the validity and the limitation of these approaches. The most often used models in the open literature are reviewed and discussed focusing on the effective properties involving tortuosity factors, solid product morphologies, as well as effects on the void space clogging, surface area reduction and passivation. Comments and suggestions are also provided for better understanding of multi-phase transport phenomena and implementation of the detailed models for solid product generation and morphology growth in Li-air battery cathodes. (C) 2014 Elsevier B.V. All rights reserved. Sun, 15 Mar 2015 00:00:00 GMT https://scholar.korea.ac.kr/handle/2021.sw.korea/94130 2015-03-15T00:00:00Z https://scholar.korea.ac.kr/handle/2021.sw.korea/96180 Title: The role of iron in the preparation and oxygen reduction reaction activity of nitrogen-doped carbon Authors: Yang, Dae-Soo; Song, Min Young; Singh, Kiran Pal; Yu, Jong-Sung Abstract: It has been considered that the presence of Fe-N in the carbon network helps to enhance oxygen reduction reaction (ORR) activity of the carbon. In this study, N-doped platelet ordered mesoporous carbon is prepared using Fe-phthalocyanine as a single precursor for nitrogen, iron and carbon sources. We show that the physical presence of Fe is not necessary to enhance the ORR activity of N-doped carbon, although Fe is required to create more active sites and to increase the electrical conductivity in the carbon framework. Thu, 01 Jan 2015 00:00:00 GMT https://scholar.korea.ac.kr/handle/2021.sw.korea/96180 2015-01-01T00:00:00Z https://scholar.korea.ac.kr/handle/2021.sw.korea/96318 Title: Simple approach to advanced binder-free nitrogen-doped graphene electrode for lithium batteries Authors: Park, Hyean-Yeol; Singh, Kiran Pal; Yang, Dae-Soo; Yu, Jong-Sung Abstract: A simple binder-free synthesis approach of just rubbing nitrogen-doped reduced graphene oxide (N-RGO) powder on a mechanically grinded Cu-foil substrate with a rough surface is proposed for a lithium ion battery (LIB). The nitrogen content of N-RGO is found to be 2.1 wt%. The binder-free N-RGO electrode shows excellent reversible capacity of 551 mA h g(-1) as compared to 433 mA h g(-1) of the binder-added N-RGO electrode at a current density of 50 mA g(-1) after 100 cycles. The process is not only highly reproducible and successful, but also results in high LIB performance, proposing easy scaling-up of such an electrode for commercial application. Thu, 01 Jan 2015 00:00:00 GMT https://scholar.korea.ac.kr/handle/2021.sw.korea/96318 2015-01-01T00:00:00Z https://scholar.korea.ac.kr/handle/2021.sw.korea/96622 Title: Surface Modification of Polypropylene Separators in Lithium-Ion Batteries Using Inductively Coupled Plasma Treatment Authors: Son, Jinyoung; Kim, Min-Sik; Lee, Hyun Woo; Yu, Jong-Sung; Kwon, Kwang-Ho Abstract: We describe herein an improvement in the surface wettability of plasma-treated separators for use in lithium-ion batteries. We treated the separators with an O-2/Ar inductively coupled plasma to increase their surface energy. The plasma treatment on the separator and plasma diagnostic experiments were performed in an inductively coupled plasma (ICP) reactor. The fraction of Ar in the O-2/Ar plasma was changed from 0% to 100%. The plasma diagnostics were performed using optical emission spectroscopy and a double Langmuir probe. To confirm the morphological change of the separator membrane by the plasma treatment, we used the scanning electron microscopy. The surface energy measurements were performed using the drop method. We found that the plasma treatment transformed the separator from a hydrophobic membrane to a hydrophilic one, thereby achieving high separator wettability. After the treatment of the separators with O-2/Ar plasma, the batteries exhibited better cycle performance and rate capacity than those employing the untreated ones. Mon, 01 Dec 2014 00:00:00 GMT https://scholar.korea.ac.kr/handle/2021.sw.korea/96622 2014-12-01T00:00:00Z