• Journal of Electrochemical Science and Technology
• /
• 제12권4호
• /
• pp.453-457
• /
• 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
• /
• 제32권10호
• /
• pp.3682-3686
• /
• 2011

The electrochemical properties of lithium-sulfur batteries with binary electrolytes based on DME and DOL, TEGDME and DOL mixed solvent containing $LiClO_4$, LiTFSI, and LiTF salts were investigated. The ionic conductivity of 1M LiTFSI and $LiClO_4$ electrolytes based on TEGDME and DOL increased as the volume ratio of DOL solvent increased, because DOL effectively reduces the viscosity of the above electrolytes medium under the same salts concentration. The first discharge capacity of lithium-sulfur batteries in the DME and DOL-based electrolyte followed this order: LiTFSI (1,000 mAh/g) > LiTF (850 mAh/g) > $LiClO_4$ (750 mAh/g). In case of the electrolyte based on TEGDME and DOL, the first discharge capacity of batteries followed this order: $LiClO_4$ (1,030 mAh/g) > LiTF (770 mAh/g) > LiTFSI (750 mAh/g). The cyclic efficiency of lithium-sulfur batteries at 1M $LiClO_4$ electrolytes is higher than that of batteries at other lithium salts-based electrolytes. Lithium-sulfur battery showed discharge capacity of 550 mAh/g until 20 cycles at all electrolytes based on DME and DOL solvent. By contrast, the discharge capacity of batteries was about 450 mAh/g at 1M LiTFSI and LiTF electrolytes based on TEGDME and DOL solvent after 20 cycles.

• 한국기후변화학회지
• /
• 제6권4호
• /
• pp.367-377
• /
• 2015

This study analyzed the effectiveness of China's policy to reduce of sulfur dioxide. China's $12^{th}$ Five-year plan on national economic and social development emphasized environmental protection and low-carbon economic development. Sulfur dioxide was one of the major gases to affect air pollution and climate change and its control became a key policy agenda in the environment and energy sector. As the absolute amount of sulfur dioxide emissions in China came from the industrial sector, the control of the coal-based energy was especially urgent. This study analyzed the factors that influenced the sulfur dioxide emissions and the policy effects to reduce sulfur dioxide in China from 2003 to 2012 based on regional data. The air pollution treatment investments showed the biggest impact together with energy conservation policy in reducing sulfur dioxide emissions. However, pollutant emissions charge did not show a relevant policy effectiveness in all regions as the amount of charge would be smaller than economic benefit from non-compliance. Rationalizing pollutant emissions charge is, therefore, a key policy task for further reduction of sulfur dioxide emissions.

• 한국재료학회지
• /
• 제16권3호
• /
• pp.193-197
• /
• 2006

The sodium/sulfur(Na/S) battery has many advantages such as high theoretical specific energy(760Wh/kg), and low material cost based on the abundance of electrode material in the earth. It has been reported that the electrochemical properties of sodium/sulfur cell above $300^{\circ}C$, utilized a solid ceramic electrolyte and liquid sodium and sulfur electrodes. A lot of researches have been performed in this field. Recently, Na/S battery system was applied for electricity storage system for load-leveling. One of severe problems of sodium/sulfur battery was high operating temperature above $300^{\circ}C$, which could induce the explosion and corrosion by molten sodium, sulfur and polysulfides. In order to develop sodium battery operated at low temperature, sodium ion battery has been studied using carbon anode, and sodium oxides cathodes. However, the energy densities of the sodium ion batteries were much lower than high temperature sodium/sulfur cell. In this study, the sodium/sulfur battery with 1M $NaCF_3SO_3$ is tested at room temperature. The charge-discharge mechanism was discussed based on XRD, DSC, SEM and EDS results.

• Journal of Korean Society for Atmospheric Environment
• /
• 제12권E호
• /
• pp.1-18
• /
• 1996

In this review, the significance of terrestrial ecosystems in the global sulfur budget has been reviewed based on the currently available databases covering the topic. In the section 1, we describe our current understanding of natural sulfur cycle in relation to most well-known natural reservoir, oceanic environment. The sections 2 and 3 provide the fundamental pictures of the rerrestrial sulfur cycle with respect to the relative importance of its individe the fundamental pictures of the terrestrial sulfur cycle with respect to the section 3, previously reported flux values for several major sulfur gases are presented for each reservoir and are intercompared to derive representative fluxes for the respective environment. In the section 4, source mechanisms for volatile sulfur species are dealt for both microscale and macroscale processes leading to their productions. In the section 5, environmental factors controlling the exchange of biogenic sulfur gases across the air-surface have been discussed. In the section 6, environmental fate of sulfur gases released into the atmosphere has been described. Finally in tie section 7, as concluding remarksm we discuss directions and suggestions to overcome various limitations encountered from previous measurement investigations of natural sulfur cycle in diverse natural ecological systems.

• Environmental Engineering Research
• /
• 제7권3호
• /
• pp.129-136
• /
• 2002

• Journal of Electrochemical Science and Technology
• /
• 제7권3호
• /
• pp.228-233
• /
• 2016

It is hard to employ the carbon materials or the lithium metal foil for the anode of lithium sulfur batteries because of the poor passivation in ether-based electrolytes and the formation of lithium dendrites, respectively. Herein, we investigated the electrochemical characteristics of lithium sulfur batteries with lithiated silicon anode in the liquid electrolytes based on ether solvents. The silicon anodes were lithiated by direct contact with lithium foil in a 1M lithium bis(trifluoromethane sulfonyl) imide (LiTFSI) solution in 1,2-dimethoxyethane (DME) and 1,3-dioxolane (DOL) at a volume ratio of 1:1. They were readily lithiated up to ~40% of their theoretical capacity with a 30 min contact time. In particular, the carbon mesh reported in our previous work was employed in order to maximize the performance by capturing the dissolved polysulfide in sulfur cathode. The reversible specific capacity of the lithiated silicon-sulfur batteries with carbon mesh was 1,129 mAh/g during the first cycle, and was maintained at 297 mAh/g even after 50 cycles at 0.2 C, without any problems of poor passivation or lithium dendrite formation.

• 한국건축시공학회지
• /
• 제14권1호
• /
• pp.61-67
• /
• 2014

산업의 발달로 인하여 매년 공업용 유황의 생산량은 증가하는 추세이다. 따라서 본 연구에서는 융점이 약 $65^{\circ}C$인 개질유황을 모르타르에 첨가하여 비빔방법 및 양생조건에 따른 개질유황 모르타르의 분포도 및 강도특성을 연구함으로써 개질유황을 모르타르 또는 콘크리트 활용방안에 대한 기초자료로 활용하고자 하였다. 실험결과, 비빔방법에서는 잔골재, 시멘트를 비빔한 뒤 물을 넣고 비비고 마지막으로 개질유황을 첨가하는 방법이 유동성과 강도면에서 가장 유리한 것으로 사료되며, EDS분석을 통한 유황의 분포도 또한 가장 좋은 것으로 나타났다. 양생조건에서는 수중양생과 기건양생 $20^{\circ}C$에서 가장 높은 압축강도를 발현한 것으로 나타났으며, $40^{\circ}C$이상의 양생을 할 경우 장기강도에서 악 영향을 미치는 것으로 나타났다.

• 한국포장학회지
• /
• 제26권3호
• /
• pp.125-131
• /
• 2020

Carrageenan-based functional films were prepared by adding two different types of sulfur nanoparticles (SNP) synthesized from sodium thiosulfate (SNPSTS) and elemental sulfur (SNPES). The films were characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction spectroscopy (XRD), and thermal gravimetric analysis (TGA). Also, film properties such as UV-visible light transmittance, water contact angle (WCA), water vapor permeability (WVP), mechanical properties, and antibacterial activity were evaluated. SNPs were uniformly dispersed in the carrageenan matrix to form flexible films. The addition of SNP significantly increased the film properties such as water vapor barrier and surface hydrophobicity but did not affect the mechanical properties. The carrageenan/SNP composite film showed some antibacterial activity against foodborne pathogenic bacteria, L. monocytogenes and E. coli.

• 한국동물위생학회지
• /
• 제35권3호
• /
• pp.197-205
• /
• 2012

Despite of a long history of the sulfur on the disease healing effect, there were limited ways of applying sulfur to animal and human. We have developed the detoxified sulfur (non toxic sulfur) method to make it practical and mass production possible through laboring for many years. This study practiced scanning electron microscope (SEM), Energy dispersive X-ray spectrometer (EDS) and secondary ion mass spectrometry (SIMS) analysis to investigate the physicochemical aspect of detoxified sulfur. We also performed the oral toxicity experiment to mice, and anti-bacterial test of the detoxified sulfur. Based on the SEM, EDS and SIMS results, the united particles in the mass form with the similar component intensity with the raw sulfur were observed, and hydrogen sulfide ion (HS-) component which is regarded as a toxic matter, was decreased after detoxification. Indeed, toxicity test on the mice (10 males, 10 females) showed no clinical, histopathological changes with the 5 times amount (2,500 mg/kg) of the actual doses. However, the male-mice showed decreased in body weight by 23.6%, 24.3% in the 7th, 14th day, respectively, after detoxified sulfur. Moreover, the female-mice administered the detoxified sulfur showed decreased in body weight by 28.7% (P<0.05) than that in the control group on the 14th day. The result of antibacterial test on the detoxified sulfur showed antibacterial effect (27%) to inhibit the growth of Staphylococcus aureus. It is shown that detoxified sulfur can be used as feed additive and has an affect on the farm perfomance.