• Journal of Electrochemical Science and Technology
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• 제12권4호
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• pp.453-457
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• 2021

Lithium-sulfur (Li-S) batteries are one of attractive energy conversion and storage system based on high theoretical specific capacity and energy density with low costs. However, volatile nature of elemental sulfur is one of critical problem for their practical acceptance in industry because it considerably affects electrode uniformity during electrode manufacturing. In this work, polymeric sulfur composite consisting of ionic liquid (IL) are suggested to reduce volatility nature of elemental sulfur, resulting in better processibility of the Li-S cell. According to systematic spectroscopic analysis, it is found that polymeric sulfur is consisting of repeating units combining with elemental sulfur and volatility of them is negligible even at high temperature. In addition, the IL-embedded polymeric sulfur shows moderate cycle performance compared to the cell with elemental sulfur. From these results, it is found that the IL-embedded polymeric sulfur composite is applicable cathode candidate for the Li-S cell based on their excellent non-volatility as well as their superior electrochemical performance.

• Bulletin of the Korean Chemical Society
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• 제28권6호
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• pp.959-964
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• 2007

The benzene complexes with dimethyl sulfur (DMS) and fluorinated DMS (FDMS) have been investigated using ab initio calculations. The natural bond orbital (NBO) charge population on S atom varies remarkably for different conformations of DMS and FDMS, which determines the possible binding modes for their benzene complexes. The electronegative substituent at the methyl group of DMS causes a significant change in the molecular electrostatic potential around the sulfur atom and changes the interaction mode with aromatic ring. It was found that the sulfur…π interaction mode does not occur in the DMS-benzene complex, while it does in the FDMS-benzene complex. Both B3LYP and MP2 methods provide reliable structures, while the interaction energy obtained by B3LYP is unreliable.

• Bulletin of the Korean Chemical Society
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• 제27권2호
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• pp.319-321
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• 2006

• Bulletin of the Korean Chemical Society
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• 제3권4호
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• pp.133-139
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• 1982

It has been presumed that the molten sulfur above $159^{\circ}C$ consists of an equilibrium mixture of $S_8$ rings and $S_x$ polymers where the number average degree of polymerization, P, is large. But it is known that admixture of halogens with liquid sulfur greatly reduce the viscosity. Constructing a new equilibrium equation, it is possible to evaluate the viscosity when halogens are added to liquid sulfur. Calculated viscosity is in good agreement with experimental values. Using the proposed model, the thermodynamic properties of liquid sulfur are also calculated over a wide range of temperature which the sulfur exists as the polymer.

• Bulletin of the Korean Chemical Society
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• 제26권11호
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• pp.1853-1855
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• 2005

• 한국결정학회지
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• 제16권1호
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• pp.21-29
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• 2005

거울상 이성질체인 di-(2-picolyl) sulfur dichloro Zinc(II), $C_{12}H_{12}N_2SCl_2Zn$의 결정구조가 두 개의 공간군 $P4_12_12\;과\;P4_32_12$로 밝혀질 수 있었다. 그러나 공간군 $P4_12_12$를 갖는 그의 absolute configuration이 anomalous dispersion의 효과에 의하여 확인되었다.

• The Korean Journal of Ceramics
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• 제5권2호
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• pp.178-182
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• 1999

Simple binary $Na_2S-SiO_2$ oxysulfide glasses were prepared by a conventional melt-quench method in order to investigate the role of sulfur in glass structure and the electronic state. By X-ray photoelectron spectroscopy(XPS) measurement, S2p binding energy of the glass was observed at approximately 161eV which was close to that of ionic $S^{2-}$. The coordinating state around silicon atoms were investigated by ${29}^Si$ MAS-NMR measurement. The chemical shift observed from NMR supported that sulfur atom was joined to a silicon atom by substituting for an oxygen atom and was present as a non-bridging sulfide ion in low alkali content. On the other hand, it could be presumed that a portion of sulfur anions existed in an isolated state from the glass-network frame at high alkali content. The state of these sulfurs was also studied by Raman spectroscopy in detail.

• 한국약용작물학회지
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• 제8권4호
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• pp.378-385
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• 2000

유황시용(硫黃施用)에 따른 토양(土壤) 및 홍화(紅花)의 수량(收量)에 미치는 영향(影響)을 조사(調査)하기 위하여 유황시용량(硫黃施用量)에 따른 토양화학성(土壤化學性) 및 홍화종실(紅花種實)의 수량(收量)을 조사(調査)한 결과(結果)는 다음과 같다. 유황시용후(硫黃施用後) 홍화종실(紅花種實)의 수확기(收穫期)에 토양(土壤)을 분석(分析)한 결과(結果) 토양(土壤)의 pH와 유효인산(有效燐酸)의 함량(含量)이 감소(減少)되었다. 유황처리후(硫黃處理後) 시간(時間)이 경과(經過)함에 따라 유황(硫黃) 처리량(處理量)이 많을수록 활성철함량(活性鐵含量)과 $SO_4^{2-}$ 함량(含量)이 증가(增加)하였다. 유황시용량(硫黃施用量)이 증가함에 따라 건물중(乾物重)이 증가하였으며, 홍화종실수량(紅花種實收量)은 증가(增加) 하는 경향(傾向)이었으며 유황(硫黃) 20 kg/10a시용구(施用區)에서 가장 높았다. 따라서, 홍화재배지(紅花栽培地)의 유황처리(硫黃處理)는 수량(收量) 및 품질(品質)에 효과적(效果的)인 것으로 나타났으며, 수량구성요소(收量構成要素) 측면(側面)에서 20 kg/10a 처리(處理)가 효과적(效果的)인 것으로 판단(判斷)되었다.

• 농업과학연구
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• 제44권2호
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• pp.261-271
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• 2017

The aim of this study was to investigate the amount of glucosinolates (GSLs) in kale sprouts (Brassica oleracea L. var. acephala) ('TBC') according to different concentrations of sulfur ions in sprout's nutrient solutions (0.0, 0.5, 1.0, and 2.0 mM) and to different light sources [Fluorescent lamp, Red, Blue, and Mix (R+B) LED]. Kale sprouts were cultivated in a growth chamber for 13 days in sulfur solutions. Kale sprouts were treated with fluorescent lamp and LED light sources for 5 days, from eight days after sowing to harvest. Amount of seven types of GSLs (progoitrin, sinigrin, 4-hydroxyglucobrassicin, glucobrassicin, 4-methoxyglucobrassicin, gluconasturtiin, and neoglucobrassicin) were measured in kale sprouts after harvest. The total GSL content was influenced by different sulfur solution concentration, and it was the highest at S 0.5 mM ($172.54{\mu}mol{\cdot}g^{-1}DW$) and the lowest at S 2.0 mM ($163.09{\mu}mol{\cdot}g^{-1}DW$). The GSL content was influenced by different light source, and it was the highest with Red LED ($159.23{\mu}mol{\cdot}g^{-1}DW$) and the lowest with Blue LED ($147.57{\mu}mol{\cdot}g^{-1}DW$). As the sulfur solution concentration increased under all light source, progoitrin and sinigrin contents tended to decrease while glucobrassicin content showed an upward tendency for all of the light sources. The content of glucobrassicin was higher than that of progitrin when treated with sulfur solutions for all LED light sources. Sinigrin, which has excellent anti-cancer effects, showed the highest rate (92.2%) among all the GSLs, under all of the light sources.

• Bulletin of the Korean Chemical Society
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• 제27권9호
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• pp.1310-1314
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• 2006

Sulfur-substituted $LiMn_{0.9}Cr_{0.1}O_{2-x}S_x$ $(0\;\leq\;x\;\leq\;0.1)$ layered oxides have been prepared by solid state reaction under inert atmosphere. From powder X-ray diffraction analyses, all the present lithium manganates were found to be crystallized with monoclinic-layered structure. Electrochemical measurements clearly demonstrated that, in comparison with the pristine $LiMn_{0.9}Cr_{0.1}O_2$, the sulfur-substituted derivatives exhibit smaller discharge capacities for the entire cycle range but the recovery of discharge capacity after the initial several cycles becomes faster upon sulfur substitution. The effect of the sulfur substitution on the chemical bonding nature of $LiMn_{0.9}Cr_{0.1}O_{2-x}S_x$has been investigated using X-ray absorption spectroscopic (XAS) analyses at Mn and Cr K-edges. According to Mn K-edge XAS results, the trivalent oxidation state of manganese ion remains unchanged before and after the substitution whereas the local structure around manganese ions becomes more distorted with increasing the substitution rate of sulfur. On the other hand, the replacement of oxygen with sulfur has negligible influence on the local atomic arrangement around chromium ions, which is surely due to the high octahedral stabilization energy of $Cr^{+III} $ ions. Based on the present experimental findings, we have suggested that the decrease of discharge capacity upon sulfur substitution is ascribable to the enhanced structural distortion of $MnO_6$ octahedra and/or to the formation of covalent Li-S bonds, and the accompanying improvement of cyclability would be related to the depression of Mn migration and/or to the pillaring effect of larger sulfur anion.