• 방사성폐기물학회지
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• 제19권2호
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• pp.271-278
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• 2021

In this study, a chlorination technique for recycling Li₂ZrO₃, a reaction product of ZrO₂-assisted rinsing process, was investigated to minimize the generation of secondary radioactive pyroprocessing waste. It was found that the reaction temperature was a key parameter that determined the reaction rate and maximum conversion ratio. In the temperature range of 400-600℃, an increase in the reaction temperature resulted in a profound increase in the reaction rate. Hence, according to the experimental results, a reaction temperature of at least 450℃ was proposed to ensure a Li₂ZrO₃ conversion ratio that exceeded 80% within 8 h of the reaction time. The activation energy was found to be 102 ± 2 kJ·mol^-1·K^-1 between 450 and 500℃. The formation of LiCl and ZrO₂ as reaction products was confirmed by X-ray diffraction analysis. The experimental results obtained at various total flow rates revealed that the overall reaction rate depends on the Cl₂ mass transfer rate in the experimental condition. The results of this study prove that the chlorination technique provides a solution to minimize the amount of radioactive waste generated during the ZrO₂-assisted rinsing process.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2003년도 가을 학술논문집
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• pp.447-452
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• 2003

산화물 핵연료의 리튬환원공정에서 생성되는 $Li_2O$와 희토류원소 산화물($RE_2O_3$)의 화학적 반응을 밝혔다. 스칸듐, 이트륨, 프라세오디뮴, 네오디뮴, 사마륨, 유러퓸, 가돌리늄, 이테르븀 및 루테튬의 산화물은 각각 어떤 $Li_2O$의 임계농도 이상에서 $Li_2O$와 반응하여 복합산화물($LiREO_2$)을 형성하고, 이들 산화물이 복합산화물을 형성하는 각각의 $Li_2O$ 임계농도는 0.1 wt%, 1.9 wt%, 5.3 wt%, 5.0 wt%, 3.0 wt%, 3.9 wt%, 2.9 wt%, 2.6 wt% 및 0.3 wt%로 나타났다. $CeO_2$ 및 란타늄 산화물은 $Li_2O$와 반응하지 않는 것으로 나타났다. 실험에서 얻은 이들 희토류원소 복합산화물의 LiCl 용융염에 대한 용해도는 매우 작았다.

• 전기화학회지
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• 제4권3호
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• pp.94-97
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• 2001

정전류법으로 다양한 전해용액에서 제조한 Polypyrrole(PPy) 필름의 캐페시턴스 특성을 cyclic voltammetry 기법을 이용하여 조사하였다. 0.5M $LiClO_4/PC(propylene carbonate)/AN(acetonitrile)$ 혼합용액에 $10\%$의 수분을 첨가한 전해질에서 제조한 PPy필름이 가장 큰 401 F/g의 커패시턴스를 나타내었다. 또한 0.5M $LiClO_4\;AN에\;10\%$의 수분을 혼합한 전해질에서 제조한 PPy필름은 2000회의 충방전에서 초기용량의 $70\%$를 나타내었다. 제조된 PPy필름의 케폐시턴스 특성은 사용된 용매에 크게 의존함을 알 수 있었다.

• 한국재료학회지
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• 제15권3호
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• pp.155-160
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• 2005

The electrolytic reduction of spent oxide fuel involves the liberation of oxygen in a molten LiCl electrolyte, which results in a chemically aggressive environment that is very corrosive fir typical structural materials. So, it is essential to choose the optimum material f3r the process equipment handling molten salt. In this study, the corrosion behavior of Al-Y coated Haynes 263 in a molten salt of $LiCl-Li_2O$ under oxidation atmosphere was investigated at $650^{\circ}C$ for $72\~168$ hours. The corrosion rate of Al-Y coated Haynes 263 was low while that of bare Haynes 263 was high in a molten salt of $LiCl-Li_2O$. Al-Y coated Haynes 263 improved the corrosion resistance better than bare Haynes 263 alloy. An Al oxide layer acts as a protective film which Prohibits Penetration of oxygen. Corrosion Products were formed $Li(Ni,Co)O_2$ and $LiTiO_2$ on bare Haynes 263, but $LiAlO_2,\;Li_5Fe_5O_8\;and\;LiTiO_2$ on Al-Y coated Haynes 263.

• 한국분말재료학회지
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• 제21권3호
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• pp.185-190
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• 2014

$FeS_2$ has been widely used for cathode materials in thermal battery because of its high stability and current capability at high operation temperature. Salts such as a LiCl-KCl were added as a binder for improving electrical performance and formability of $FeS_2$ cathode powder. In this study, the effects of the addition of $Li_2O$ in LiCl-KCl binder on the formability of $FeS_2$ powder compact were investigated. With the increasing amount of $Li_2O$ addition to LiCl-KCl binder salts, the strength of the pressed compacts increased considerably when the powder mixture were pre-heat-treated above $350^{\circ}C$. The heat-treatment resulted in promoting the coating coverage of $FeS_2$ particles by the salts as $Li_2O$ was added. The observed coating as $Li_2O$ addition might be attributed to the enhanced wettability of the salt rather than its reduced melting temperature. The high strength of compacts by the $Li_2O$ addition and pre-heat-treatment could improve the formability of $FeS_2$ raw materials.

• 한국재료학회지
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• 제23권2호
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• pp.123-127
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• 2013

The electrolytic reduction of a spent oxide fuel involves liberation of the oxygen in a molten LiCl electrolyte, which is a chemically aggressive environment that is too crosive for typical structural materials. Therefore, it is essential to choose the optimum material for the process equipment for handling a molten salt. In this study, the corrosion behavior of pyro-carbon made by CVD was investigated in a molten LiCl-$Li_2O$ salt under an oxidation atmosphere at $650^{\circ}C$ and $750^{\circ}C$ for 72 hours. Pyro-carbon showed no chemical reactions with the molten salt because of its low wettability between pyro-carbon and the molten salt. As a result of XRD analysis, pyro-carbon exposed to the molten salt showed pure graphite after corrosion tests. As a result of TGA, whereas the coated layer by CVD showed high anti-oxidation, the non-coated layer showed relatively low anti-oxidation. The stable phases in the reactions were $C_{(S)}$, $Li_2CO_{3(S)}$, $LiCl_{(l)}$, $Li_2O$ at $650^{\circ}C$ and $C_{(S)}$, $LiCl_{(l)}$, $Li_2O_{(S)}$ at $750^{\circ}C$. $Li_2CO_{(S)}$ was decomposed at $750^{\circ}C$ into $Li_2O_{(S)}$ and $CO_{2(g)}$.

• 한국재료학회지
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• 제14권11호
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• pp.813-820
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• 2004

The electrolytic reduction of spent oxide fuel involves the liberation of oxygen in a molten LiCl electrolyte, which is a chemically aggressive environment that is very corrosive for typical structural materials. So, it is essential to choose the optimum material for the process equipment handling molten salt. In this study, corrosion behavior of Haynes 263, 75, and Inconel X-750, 718 in molten salt of $LiCl-Li_{2}O$ under oxidation atmosphere was investigated at $650^{\circ}C\;for\;72\sim360$ hours. At $3\;wt\%\;of\;Li_{2}O$, Haynes 263 alloy showed the highest corrosion resistance among the examined alloys, and up to $8\;wt\%\;of\;Li_{2}O$, Haynes 75 exhibited the highest corrosion resistance. Corrosion products were formed $Li(Ni,Co)O_2,\;LiNiO_2\;and\;LiTiO_2\;and\;Cr_{2}O_3$ on Haynes 263, $Cr_{2}O_3,\;NiFe_{2}O_4,\;LiNiO_2,\;Li_{2}NiFe_{2}O_4,\;Li_{2}Ni_{8}O_10$ and Ni on Haynes 75, $Cr_{2}O_3,\;(Al,Nb,Ti)O_2,\;NiFe_{2}O_4,\;and\;Li_{2}NiFe_{2}O_4$ on Inconel X-750 and $Cr_{2}O_3,\;NiFe_{2}O_4\;and\;CrNbO_4$ on Inconel 718, respectively. Haynes 263 showed local corrosion behavior and Haynes 75, Inconel X-750, 718 showed uniform corrosion behavior.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1994년도 추계학술대회 논문집
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• pp.82-85
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• 1994

The purpose of this study is to research and develop solid polymer electrolyte(SPE) for Li secondary battery. This paper describes effects of plasticizer addition and temperature dependence of conductivity of these PEO electrolytes. Adding propylene carbonate and ethylene carbonate to PEO-LiClO$_4$electrolyte, its conductivity was higher than PEO-LiClO$_4$ itself. Steady state current method and AC impedance used for the determination of transference number in PEO electrolyte film. The transference number of PEO$\_$8/LiClO$_4$PC$\_$5/EC$\_$5/ polymer electrolyte film is 0.45 at 60$^{\circ}C$.

• 폴리머
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• 제27권3호
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• pp.265-270
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• 2003

고분자 젤은 높은 이온 전도도를 가지는 대신에 나쁜 기계적 물성 때문에 많은 문제점을 가지고 있다. 다소 낮은 이온 전도도를 나타내면서 기계적, 열적, 화학적, 전기 화학적으로 우수한 특성을 가지는 근식 고체계와, 고분자 복합재료에 대한 많은 연구들이 진행 중에 있다. 본 연구는 PEO-LiClO$_4$(8:1)에 기초한 고체 고분자 전해질에 액체 상의 가소제가 아닌 고체 상으로 가소제의 역할을 하는 세라믹과 고무를 첨가시켜서 이온 전도도와 기계적 물성을 증가시키는 것에 대한 것이다. 이온 전도도는 세라믹 상과 고무상을 도입한 두 가지 경우 모두 ~$10^{-5}$ $cm^{-1}$ / 정도로 비슷하게 나타났는데, 이는 현재까지 연구되어진 것 중 최고의 값을 가지는 것과 비슷했다. 더 높은 이온 전도도를 얻기 위하여 다양한 분자량 (600~8000)을 가진 고분자를 혼합하였고, 염의 함량에 변화를 주었다. 염의 첨가와 첨가된 염의 함량에 따라 높은 결정성을 가지는 PEO가 무정형으로 바뀌는 것을 DSC 곡선을 통해 알 수 있었고, 다양한 함량의 LiClO$_4$를 첨가한 경우 고분자 유동성의 변화를 FT-IR을 통해 알 수 있었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 영호남학술대회 논문집
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• pp.261-264
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• 2000

The purpose of this study is to research and develop solid polymer electrolyte(SPE) for Li polymer battery. This paper describes temperature dependence of conductivity, impedance spectroscopy, electrochemical properties of PAN/PVDF electrolytes as a function of a mixed ratio. PAN/PVDF based polymer electrolyte films were prepared by thermal gellification method of preweighed PAN/PVDF, plasticizer and Li salt. By adding PVDF and as a function of plasticizer mixed ratio to PAN-LiClO4 electrolyte, its conductivity was higher than that of PAN-$LiClO4_4$ electrolyte. The conductivity of PAN/PVDF electrolytes was $10^{-3}S/cm$. $10PAN10PVDFLiClO_4PC_5EC_5$ electrolyte shows the better conductivity of the others. Steady state current method and ac impedance used for the determination of transference numbers in PAN/PVDF electrolyte film. The transference number of $10PAN10PVDFLiClO_4PC_5EC_5$ electrolyte is 0.45.