Doyoung Seung
Samsung
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Publication
Featured researches published by Doyoung Seung.
Solid State Ionics | 2000
Kyoung-Hee Lee; Young-Gi Lee; Jung-Ki Park; Doyoung Seung
Abstract Composite polymer electrolyte films consisting of poly(acrylonitrile-co-methyl methacrylate) (P(AN-co-MMA)), EC–PC, LiClO 4 salts, and also silica particles have been prepared, and their electrochemical properties were studied. A maximum in the ion conductivity was found for the plasticized polymer electrolyte containing 10 wt% silica with EC–PC and was 1.7×10 −4 S/cm at −15°C and 1.9×10 −3 S/cm at 25°C. The reduction in T g of the plasticizer-rich phase in the composite polymer electrolytes due to the interaction between the added silica and lithium cation seems to be a main reason for the initial increase of the ion conductivities with the increase in the silica content. The decrease in the ion conductivity with the silica content at the higher silica content is expected to be attributed to the increase of viscosity of the plasticizer-rich phase and the decrease in the charge carrier numbers. The stability of interfacial resistance between the composite polymer electrolyte and the lithium electrode was found to be enhanced with increase of the silica content in the range studied.
Journal of Power Sources | 2001
C. Storey; I. Kargina; Y. Grincourt; Isobel J. Davidson; Y.C. Yoo; Doyoung Seung
Abstract This paper reports on the electrochemistry of a new series of layered manganese oxide cathodes for lithium-ion cells. The layered structure is stabilized by the partial substitution of the manganese by chromium and lithium atoms and by the partial or complete oxidation of the manganese to the +4 oxidation state. The series covers the range of compositions Li x Cr y Mn 2− y O 4+ z for which 2.2 x y z ≥0.
Korean Journal of Chemical Engineering | 2002
Doo-yeon Lee; Hyo-sug Lee; Ho-sung Kim; Hee-young Sun; Doyoung Seung
We disclosed that a few kinds of aromatic compounds having thianthrene derivatives with acetyl or other functional groups were stable up to about 4.2-4.3 V against lithium. These materials, called redox shuttle, have lately been employed as a chemical overcharge protection agent that consumes the excess current during battery overcharge. They oxidized above 4 V and worked as redox shuttle when introduced into the electrolyte of a Carbon/LiCoO2 prismatic battery within less than one hour rate (1C). We also studied thermal properties of batteries containing the above-mentioned materials with ARC (Accelerating Rate Calorimeter). We ascertained that the current supplied over the full charge was not stored, but instantly and quite completely consumed in an oxidation-reduction reaction.
Chemical Communications | 2005
Hyung Ik Lee; Chanho Pak; Chae-Ho Shin; Hyuk Chang; Doyoung Seung; Jae Eui Yie; Ji Man Kim
Combining both nano-replication and nano-imprinting techniques using dual silica templates provides a simple way to synthesize ordered mesoporous carbons with bimodal pore size distributions ( approximately 1.5 nm and approximately 3.5 nm).
Studies in Surface Science and Catalysis | 2007
Chanho Pak; Sang Hoon Joo; Dae Jong You; Ji Man Kim; Hyuk Chang; Doyoung Seung
Ordered mesoporous carbon (OMC) prepared by nano-replication method was directly functionalized with sulfonic acid group by using the ammonium sulfate salts. PtRu nanoparticles below 3 nm was supported on the sulfonated-OMC support with 70 wt% loading, and the resulting catalysts exhibited promising catalytic activity for methanol oxidation reactions.
Studies in Surface Science and Catalysis | 2007
Chanho Pak; Sang Hoon Joo; Dae Jong You; Hyung Ik Lee; Ji Man Kim; Hyuk Chang; Doyoung Seung
As a new carbon support for the fuel cell, ordered mesoporous carbon (OMC) was prepared by the nano template method using ordered mesoporous silica. The structural properties of OMC such as microporosity and graphitic character were controlled by addition of nano silica powder during synthesis of OMC or the uses of different carbon precursors. The performance of direct methanol fuel cell in the single cell was affected significantly by the graphitic character of OMC support.
Electrochimica Acta | 2006
Sang Hoon Joo; Chanho Pak; Dae Jong You; Seol-Ah Lee; Hyung Ik Lee; Ji Man Kim; Hyuk Chang; Doyoung Seung
Carbon | 2008
Sang Hoon Joo; Hyung Ik Lee; Dae Jong You; Kyungjung Kwon; Jin Hoe Kim; Yeong Suk Choi; Min Kang; Ji Man Kim; Chanho Pak; Hyuk Chang; Doyoung Seung
Advanced Materials | 2008
Hyung Ik Lee; Jin Hoe Kim; Dae Jong You; Ji Eun Lee; Ji Man Kim; Wha-Seung Ahn; Chanho Pak; Sang Hoon Joo; Hyuk Chang; Doyoung Seung
Journal of Power Sources | 2006
Weimin Chen; Gongquan Sun; Zhenxing Liang; Qing Mao; Huanqiao Li; Guoxiong Wang; Qin Xin; Hyuk Chang; Chanho Pak; Doyoung Seung