• Title/Summary/Keyword: Li salt

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Characteristics of Salt Concentration in Electrolyte of Lithium Ion Battery According to Sudden Temperature Change (급격한 온도 변화에 따른 리튬 이온 배터리의 전해질 내 염 농도 분포 특성)

  • Jang, Kyung Min;Kim, Kwang Sun
    • Journal of the Semiconductor & Display Technology
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    • v.16 no.1
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    • pp.11-15
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    • 2017
  • Lithium-ion batteries are widely used, from lightweight to energy-intensive, from small devices to large ESSs. However, it is sensitive to the surrounding environment and there is a change in performance depending on the temperature change. In this study, the temperature dependence of the charge / discharge characteristics of the battery is shown through simulation and the distribution of the salt concentration in the electrolyte is observed when the sudden temperature change is applied.

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A System Development of Thermal Energy Storage at High Temperatures (고온 축열 시스템의 개발에 관한 연구)

  • Hong, Seong-Ahn;Park, Won-Hoon;Choe, Hyung-Joon
    • Solar Energy
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    • v.8 no.1
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    • pp.13-21
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    • 1988
  • Heat transfer phenomena in a high-temperature heat storage unit were investigated using molten salts. Carbonate salt, an equimolar mixture of $Li_2CO_3$ and $K_2CO_3$, which melts at $505^{\circ}C$ with a latent heat of 82 cal/g, was selected as the most promising latent heat storage material based on its low cost and excellent thermophysical properties at moderately high temperatures. It was also found that nitrate salts were good candidates of sensible heat storage materials. For the carbonate salt to be utilized commercially, however, several means of enhancing thermal recovery must be explored by promoting heat conduction through the solid salt formed during the heat discharge period. These would be achieved by the additions of aluminum screens and wool, and stainless fins. Finally, experimental results of moving boundary of phase change were well compared with predictied values obtained from the approximate solution.

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Electrochemical Characteristics and Physical Properties of Poly(ethylene oxide)-Li based Polymer Electrolyte (Poly(ethylene oxide)-Li계 고분자 전해질의 전기화학적 특성 및 물리적 성질)

  • Kim, Hyung-Sun;Cho, Byung-Won;Yun, Kyung-Suk;Chun, Hai-Soo
    • Applied Chemistry for Engineering
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    • v.7 no.3
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    • pp.433-442
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    • 1996
  • Electrochemical characteristics and physical properties of polymer electrolyte which immobilized lithium salts such as $LiClO_4$ and $LiCF_3SO_3$ and plasticizers such as ethylene carbonate(EC) and propylene carbonate(PC) in high molecular weight poly(ethylene oxide)[PEO] polymer was investigated. PEO-Li based polymer electrolyte with plasticizers showed ionic conductivity of $10^{-4}S/cm$ at room temperature and high electrochemical stability up to 4.5 V(vs. $Li^+/Li$), so it can be applied to lithium secondary battery. The crystallinity of PEO decreased with the addition of lithium salts and plasticizers, especially $LiClO_4$ and PC showed more effective than and $LiCF_3SO_3$ and EC. Glass transition temperature($T_g$) of polymer electrolyte increased with increasing lithium salt concentration whereas melting temperature ($T_m$) decreased. Polymer electrolyte with plasticizers crystallized at $6^{\circ}C$.

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Effect of Conductive Additives on $FeS_2$ Cathode ($FeS_2$ 양극에 미치는 전도성 첨가제의 영향)

  • Choi, Yu-Song;Cheong, Hae-Won;Kim, Ki-Youl;Cho, Sung-Baek
    • Journal of the Korea Institute of Military Science and Technology
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    • v.15 no.2
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    • pp.224-230
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    • 2012
  • Thermal batteries have excellent mechanical robustness, reliability, and long shelf life. Due to these characteristics as well as their unique activation mechanism, thermal batteries are widely adopted as military power sources. Li(Si)/$FeS_2$ thermal batteries, which are used mostly in these days, use LiCl-KCl and LiBr-LiCl-LiF as molten salt electrolyte. However, it is known that Li(Si)/$FeS_2$ thermal batteries have high internal resistance. Especially, $FeS_2$ cathode accounts for the greater part of internal resistance in unit cell. Many efforts have been put into to decrease the internal resistance of thermal batteries, which result in the development of new electrode material and new electrode manufacturing processes. But the applications of these new materials and processes are in some cases very expensive and need complicated additional processes. In this study, internal resistance study was conducted by adding carbon black and carbon nano-tube, which has high electron conductivity, into the $FeS_2$ cathode. As a results, it was found that the decrease of internal resistance of $FeS_2$ cathode by the addition of carbon black and carbon nano-tube.

Effect of Neutral Salts on the Reactive Dyeing of Silk(I) -Effect of Cations- (중성염이 견의 반응염색에 미치는 영향(I) - 양이온의 영향-)

  • 도성국;박찬헌;권지윤
    • Textile Coloration and Finishing
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    • v.12 no.6
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    • pp.372-379
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    • 2000
  • Four kinds of neutral salts with different cations, LiCl, NaCl, KCl, and CsCl, were added to the dye bath to accurately understand the effect of cations on the reactive dyeing of silk with C. I. Reactive Black 5. The cations of salts added lowered the negative surface potential of the silk, improving equilibrium adsorption and the accessibility of the dyestuff to the fiber greatly and speeding up the dyeing rate in the order of $Li^+>Na^+>K^+>Cs^+$. The activation energy$(E_a)$ for the dyeing was in the order of$Li^+>Na^+>K^+>Cs^+$ but the activation free energy$(\Delta{G}^*)$, or the real energy barrier for the reaction, was in the order of $Li^+>Na^+>K^+>Cs^+$ because the degree of the contribution of E$^{a}$ to the activation entropy$(\Delta{S}^*)$ was $Li^+>Na^+>K^+>Cs^+$. It was found from this result that LiCl had the strongest lowering effect on the negative surface potential of silk. The decrease in $\Delta{S}^*$ should be attributed to the loosely bonded activated complex of dyestufffs, cations and fiber molecules at transition state. It was clarified from the Bronsted equation that salts had the ionic strength effect and the specific salt effect on the reactive dyeing.

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