• Journal of the Korean Electrochemical Society
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• v.15 no.3
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• pp.190-197
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• 2012

We employed the vinyl ethylene carbonate (VEC) as an electrolyte additive and investigated the effect of the electrolyte additive on the electrochemical performance in hybrid capacitor. The activated carbon was adopted as cathode material, and the $Li_4Ti_5O_{12}$ oxide was used as anode material. The electrolyte was prepared with the $LiPF_6$ salt in the mixed solvent of ethylene carbonate (EC), dimethyl carbonate (DMC), and ethyl methyl carbonate(EMC). We evaluated the electrochemical performance of the hybrid capacitor with increasing the amount of the VEC electrolyte additive, which is known as the remover of oxygen functional group and the stabilizer of the electrode by reducing the surface of electrode, and obtained the superior performance data especially at the addition of the VEC electrolyte additive of around 0.7 vol%. On the contrary, the addition of the VEC more than 0.7 vol% in the electrolyte leads to the degradation in electrochemical performance of hybrid capacitor, suggesting the increase of the side reaction from the excessive VEC additive. X-ray photoelectron spectroscopy (XPS) revealed that the addition of the VEC suppressed the formation of LiF component, which is known as the insulator, on the surface of electrode. The optimized addition of VEC exhibited the improved capacity retention around 82.7% whereas the bare capacitors without VEC additive showed the 43.2% of capacity retention after 2500 cycling test.

• Journal of Sensor Science and Technology
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• v.7 no.2
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• pp.111-116
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• 1998

The simple solid electrolyte carbon dioxide sensor with heaters were fabricated by using Li ionic conductor. Two Au electrodes were used for the reference and sensing electrode respectively. Two types of gas sensors, type ( I ) and type (II), were fabricated. Type ( I ) sensor was fabricated by the method of melting and crystallizing alkali metal carbonate at the temperature of $420{\sim}500^{\circ}C$. The sensing membrane of type (II) sensor was formed by the printing method on sensing electrode after metal carbonate was mixed with binder. The response characteristics of sensors fabricated for the carbon dioxide were investigated for a range of $CO_{2}$ concentration from 950 ppm to 9,950 ppm at operating temperature $420^{\circ}C$. Type ( I ) sensor and type (II) sensor showed the sensitivity of 62 mV/decade and 65 mV/decade respectively. The emf/decade of type (II) sensor tested at $420^{\circ}C$ almost followed the theoretical value of Nernst's equation and showed stable response characteristics with the fast response time of $15{\sim}20$ sec. Also type (II) sensor showed excellent stability and reproduction properties for 60 days.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.3
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• pp.330-335
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• 2014

Objectives: To evaluate the mutagenicity of lithium carbonate, a bacterial reverse mutation(Ames) test was carried out using four strains of S. typhimurium(TA1535; TA1537; TA98; and TA100) and one strain of E. coli(WP2uvrA). Materials: This was carried out in a dose range from 312.5 to $5,000{\mu}g/plate$ in triplicate with and without S9 activation, which is the most commonly used metabolic activation system supplemented by a post-mitochondrial fraction prepared from the livers of rodents treated with enzyme-inducing agents such as Aroclor 1254 or a combination of phenobarbitone and ${\beta}$-naphthoflavone. Results: No significant increases in the number of revertants were observed under the conditions examined in this study. Conclusions: Based on the above observations, it can be concluded that lithium carbonate has no mutagenic activity. Despite the results, it can have an effect by inducing acute oral toxicity, eye irritation and acute aquatic toxicity. Based on this study, we suggest that future studies should be directed toward chronic, carcinogenic testing and other related areas.

• Journal of the Mineralogical Society of Korea
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• v.25 no.4
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• pp.221-231
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• 2012

Uljin cassiterite deposit had been known to be a pegmatitic origin derived from the Wangpiri (Buncheon) granitic gneiss of Precambrian period. Lithium ore also shows the same origin and its lithium bearing mineral was ascertained to be a taeniolite. But the presence of leucocratic granites which played the role of host rocks haven't been clearly designated yet in these provinces. Even though Bonghwa and Youngweol sericite deposits situated in the vicinities of Hambaeg syncline had been known to have their host rocks as Hongjesa Granites of Precambrian period and Pegmatitic migmatite of unknown age respectively. But younger leucocratic granites are characterized by more amounts of albite and sericite (muscovite-3T type) than those of the older granitic rocks which contain plenty of biotite and chlorites. Although the younger granites show rather higher contents of alkalies such as $Na_2O$ (0.13~8.03 wt%) and $K_2O$ (1.71~6.38 wt%), but CaO (0.05~1.21 wt%) is very deficient due to the albitization and greisenization. Manisan granite, which is assumed to be Daebo granite which intruded the Gyunggi Gneiss Complex was again intruded by leucocratic granite whose microclinized part changed into kaolins. Taebaegsan region shows a wide distribution of carbonate rocks which are especially favorable to the ore depositions. And the presence of alkali granites which formed in the later magmatic evolution are well known to be worthwhile to the prospections of various rare metals and REEs resources.

• Mineral and Industry
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• v.27
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• pp.8-15
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• 2014

In this study, a proposal for revision of HSK Code was established on legally designated minerals and national stockpile minerals. It is difficult to exactly identify trade balances of minerals, such as lithium ore, rare earth ore, serpentine, kidney stone in legally designated minerals and ingot of indium, ferro-tungsten, ingot of antimony, granule of selenium, gallium, lanthanum oxide, cerium carbonate in national stockpile minerals because HSK Codes of them were not allocated separately. Furthermore, specific use, standard, component, type of products cannot be exactly identified in current HSK Code system. Therefore, it is makes rule to separately manage minerals which were managed by government such as legally designated minerals and national stockpile minerals. However, a proposal for revision of HSK Code system was established to comply with international standard(HS Code) and the items over a certain size(amounts : over 50 mil.$, volumes : over 5000 ton) were selected as revised subjects. Moreover hierarchies between HSK Codes were considered.

• Transactions of the Korean hydrogen and new energy society
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• v.25 no.3
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• pp.280-288
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• 2014

SDC (Samarium doped Ceria) electrolyte was developed for Intermediate temperature SOFC ($500^{\circ}C-800^{\circ}C$) which showed a good electrical conductivity. In this study, we used sintering aids to reduce the SDC sintering temperature down to $1000^{\circ}C$, especially which can help the SOFC scale-up. In order to reduce the SDC sintering temperature, $Li_2CO_3$ and $TiO_2$ were used as a sinering aids for decreasing sintering temperature. $Li_2CO_3$ and $TiO_2$ doped SDC sintered at $1000^{\circ}C$ showed 99% of the theoretical density and higher electrical conductivity than the pure SDC sintered at $1500^{\circ}C$. When measuring the OCV (Open circuit voltage) with the $Li_2CO_3$ and $TiO_2$ doped SDC electrolyte, however, the OCV values were lower than the theoretical OCV values which means that the modified SDC still had electronic conductivity.

• Journal of the Korean Recycled Construction Resources Institute
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• v.1 no.3
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• pp.233-239
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• 2013

This study is interested in manufacturing the self-cleaning silicate concrete surface impregnant including tetra ethyl ortho silicate, lithium silicate for the repair of the exposed concrete surface and the color concrete requiring the advanced function in view of the concrete appearance. The concrete surface layer change and static contact angel was tested for the review of application. The result of this study shows that the effective silicate is tetra ethyl ortho silicate and lithium silicate. The adhesion in tension is satisfied with performance requirement of KS standard but the reinforcement of concrete substrate is slight. So, The self-cleaning silicate concrete impregnant of this study is more desirable for the improvement of durability rather than the reinforcement.