• 전기화학회지
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• 제13권4호
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• pp.290-294
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• 2010

본 연구는 밀도 범함수 이론을 이용하여 Li이온전지에 사용되는 Li코발트 산화물에서의 Li이온 삽입 전압과 전도에 관한 것이다. Li이온은 Li코발트 산화물 원자구조의 각 층을 1개씩 채우거나 한 층을 다 채우고 다음 층을 채울 수 있다. 평균 삽입 전압은 3.48V로 동일하나, 전자가 후자보다 더 유리하였다. 격자상수 c는 Li농도가 0.25보다 작을 때는 증가하였으나, 0.25보다 클 때는 감소하였다. Li농도가 증가하면, Li코발트 산화물에서의 Li이온 전도를 위한 에너지 장벽은 증가하였다. Li이온전지가 방전 중 출력 전압이 낮아지는 현상은 Li농도 증가에 따른 삽입 전압의 감소와 전도 에너지 장벽의 증가로 설명할 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제17권8호
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• pp.730-735
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• 1996

The layered perovskite oxide, KSr2Nb3O10, was synthesized. The interlayer potassium cations were readily exchanged by protons in hydrochloric acid solution to give the protonation compound, HSr2Nb3O10·0.5H2O. The intercalation compounds, [NH3(CH2)nNH3]xSr2Nb3O10, were also obtained by acid-base reactions between the protonation compound and organic bases, 1,n-alkyldiamines. The interlayer distances in the intercalation compounds were linearly increased with the increase of the number of carbon (Δc/Δn=1.05 Å) in 1,n-alkyldiamines. The intercalated alkyldiammonium ions formed a paraffin-like monolayer with average tilting angle (θ) of ca. 56°. The intercalation reactions occurred stoichiometrically. The thermal decomposition process of the intercalation compounds showed distinct three steps due to the desorption of hydrated water, the decomposition of organic moiety, and the decomposition of Sr-related compounds.

• 한국세라믹학회지
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• 제22권6호
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• pp.5-8
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• 1985

Graphite has been oxidized to graphite hydrogen sulfate in concentrated $H_2SO_4$. Anodic oxidation and chemical oxidation of graphite in $H_2SO_4$ generally leads to the formation of intercalation compounds of the ionic salt type through incorporation of $H_2SO_4^-$ions and $H_2SO_4$ molecules into the graphite. Several other reactions also accur at various points of the charging cycle. But there is no satisfactory kinetics and mechanism of intercalationin graphite. We have studied them with anodic oxidation and chemical oxidation. We found six distinct phenomena between 2nd stage and 1st stage in chemical oxidation. We examined them in detail by the following in the measurements electrical oxidation. X-ray diffractions UV-Vis spectroscopy density measurements. We could obtained a equation for kinetic according to the reaction rate from this results and mechanism of intercalation between 2nd stage and 1st stage with hydrogen sulfate in graphite. Three thesis were written for the mechanism of intercalation compounds in graphite with hydrogen sulfate ; first thesis is anodic oxidation second thesis is chemical oxidation and definition of transit phase between 2nd etc the third thesis is the kinetic mechanism of intercalation compounds in graphite with Hydrogen sulfate. This thesis is the first paper among three thesis as anodic oxidation.

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 2002년도 춘계총회 및 학술발표회
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• pp.54-55
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• 2002

• Bulletin of the Korean Chemical Society
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• 제27권1호
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• pp.82-86
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• 2006

Propylene Carbonate (PC) has the interesting properties of being able to dissolve and dissociate lithium salts, thus leading to highly conducting electrolytes even at low temperatures. Moreover, electrolytes that contain PC are stable against oxidation at voltages up to ~5 V. However, it is known that, when lithium is intercalated into graphite in pure PC based electrolytes, solvent co-intercalation occurs, leading to the destruction of the graphite structure. (i.e., exfoliation). The objective of this study was to suppress PC decomposition and prevent exfoliation of the graphite anode by co-intercalation. Electrochemical characteristics were studied using Kawasaki mesophase fine carbon (KMFC) in different 1 M $LiPF_6$/PC-based electrolytes. Electrochemical experiments were completed using chronopotentiometry, cyclic voltammetry, impedance spectroscopy, X-ray diffraction, and scanning electron microscopy. From the observed results, we conclude that the MA and $Li_2CO_3$ additive suppressed co-intercalation of the PC electrolyte into the graphite anode. The use of additives, for reducing the extent of solvent decomposition before exfoliation of the graphite anode, could therefore enhance the stability of a KMFC electrode.

• 산업기술연구
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• 제6권
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• pp.49-55
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• 1986

A rapid and simple test to distinguish halloysite from kaolinite in mineral mixtures has been developed based on differences in the rate and extent of formamide intercalation. The results of quantitative analysis by formamide intercalation reaction GEC contained 90% of kaolin minerals, GEC contained of 86% of halloysite and GYK contained of 59% kaolinite. The extent of formamide intercalation by kaolinite was likely influenced by sample crystallinity.

• EDISON SW 활용 경진대회 논문집
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• 제4회(2015년)
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• pp.408-411
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• 2015

Trilayer graphene에 비활성기체 중 하나인 Ne 원자가 어떤 영향을 미치는지에 대해 density functional theory calculation을 이용해서 연구하였다. ABA stacked trilayer graphene의 $4{\times}4$ super cell에서 top surface에 adsorption되는 경우와 trilayer 내부에 intercalation 되는 경우에 대하여 energy를 계산하여 Ne 원자들의 안정한 위치를 찾았다. Adsorption의 경우 hollow site가 가장 안정하였고 intercalation의 경우에도 top layer의 hollow site의 아래가 가장 안정하였다. 또한 Ne 원자 2개가 adsorption되는 경우의 adsorption energy를 통하여 Ne 원자들 사이의 상호작용을 예측하였다.

• 한국세라믹학회지
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• 제20권3호
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• pp.205-210
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• 1983

The determination of charge density and charge distribution in montmorillonite are discussed. The method is based on cation exchange of the inorganic interlayer cations against decylammonium ion and molecular intercalation of n-alcanol. The results obtained from Yougil-bentonite show that charge density of 0.37 per unit formula and cation exchange capacity of 102.5 meq/100g.

• Bulletin of the Korean Chemical Society
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• 제22권9호
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• pp.1019-1022
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• 2001

Negatively charged functional organic molecules such as retinoic acid, ascorbic acid, indole acetic acid, citric acid, salicylic acid, acidic dye (indigo carmine, Food Blue 1) are intercalatively encapsulated by zinc basic salt (hydrozincite) and layered double hydroxide. Such functional organic-inorganic nanohybrids are realized via coprecipitation reaction involving simultaneous formation of layered inorganic lattice and intercalation of anionic species. The heterostructural nature of these nanohybrids, their particle morphology and textural characterizations are mainly discussed on the basis of Powder X-ray Diffraction and Field Emission Scanning Electron Microscopy results.

• Bulletin of the Korean Chemical Society
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• 제19권10호
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• pp.1032-1036
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• 1998

Intercalation compounds of organic anions into layered double hydroxides (LDH) are synthesized by the coprecipitation route. X-ray diffraction data reveal that the intercalated terephthalate (TP), naphthalene-2,6-disulfonate (NA26), and anthraquinone-2,6-disulfonate (AQ26) are arranged with their molecular planes perpendicular to the hydroxide layer. HPLC data show that 26.2% of TP and 73.8% of AQ26 are cointercalated, whereas NA26 is not intercalated into the Zn/Al-LDH. These results indicate the possibility of a molecular recognition ability of Zn/Al-LDH. The molecular recognition ability of intercalation into Zn/Al-LDH is in the order AQ26 > TP >> NA26.