• Applied Chemistry for Engineering
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• v.5 no.1
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• pp.44-53
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• 1994

A study on the iron electrode which is a good material for alkaline battery because of its superior characteristics including high theoretical capacity density, low toxicity, low cost and inexhaustible supply was performed to develop high performance nickel-iron secondary battery. The characteristics of chrage-discharge reaction were examined by cyclic voltammetry technique SEM and XRD analysis. The capacity of the test electrodes was determined by the costant current charge-discharge method. It was found that the purity and particle size of iron material were the major determinant factors of electrode capacity. With the addition of $Na_2S$ into the electrolyte the capacity of electrode was increased about 20 % caused by the prevention of passivation and the increase of hydrogen overpotential. The stability and capacity of electrode were increased with the use of Ni-fibrex and foamed Ni collectors and also depended on the sintering temperature. The capacity of electrode was 350 mAh/g(0.2 C) which corresponded to 36% utility.

• Journal of the Korean Electrochemical Society
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• v.14 no.3
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• pp.152-156
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• 2011

A room temperature ionic liquid (RTIL) based on trihexyl (tetradecyl)phosphonium bis(trifluoromethanesulfonyl) imide ([$(C_6H_{13})_3P(C_{14}H_{29)}$] [TFSI];P66614TFSI) was synthesized and analyzed to determine their characteristics and properties. The bis(trifluoromethanesulfonyl)imide (TFSI) anion is widely studied as an ionic liquid (IL) forming anion which imparts many useful properties, notably electrochemical stability. Especially its electrochemical and physical characteristics for solvent of lithium ion battery were investigated in detail. $P_{66614}$ TFSI exhibits fairly low conductivity (0.89 mS $cm^{-1}$) and higher viscosity (298 K: 277 cP; 343 K: 39 cP) than other ionic liquids, but it exhibits a high thermal stability (over $400^{\circ}C$). Especially corrosion behavior on Al current collector was tested at room temperature and further it was confirmed that thermal resistivity for Al corrosion was highly increased in 1.0M LiTFSI/$P_{66614}$-TFSI electrolyte comparing with other RTILs by linear sweep thermometry.

• Applied Chemistry for Engineering
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• v.18 no.5
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• pp.449-453
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• 2007

Synthesis of Sn-GIC (Graphite intercalated compound) and its electrochemical characteristics were investigated to find a method for enhancing the performance of carbon anode of lithium ion battery. The content of Sn intercalated in graphite interlayer increased with increase of concentration of $SnCl_2$ solution and increase of the heat treatment temperature of dried graphite after dipped in $SnCl_2$ solution, respectively. And initial discharge capacity increased upon increase of intercalated Sn content. Sn-GIC with excellent electrochemical performance, which can be synthesized by heat treatment at $900^{\circ}C$ after dipped in 1.0 M $SnCl_2$ solution, showed 356 mAh/g of initial discharge capacity and 13% of capacity decay after 10 cycles.

• Korean Chemical Engineering Research
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• v.59 no.1
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• pp.35-41
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• 2021

Silicon is a promising next-generation anode material for lithium-ion battery, and it has been studied for commercialization due to the high theoretical capacity. However, it has problems of the volume change during charge-discharge and the poor electrical conductivity. To solve these problems, formation of SiO2 and carbon coating on the surface of silicon crystal were performed to protect the side reaction and enhance the electrical conductivity of silicon. CNT and CNF were also added to mitigate the volume change and increase the conductivity. Physical properties of asprepared samples were analyzed by XRD, SEM, and EDS. Electrochemical characteristics were investigated by electrical conductivity measurement, EIS, CV and cycle performance test. (Si/SiO2/C)+CNT&CNF showed high electrical conductivity and low charge-transfer resistance, and the capacity was 1528 mAh/g at 1st cycle and 1055 mAh/g at 50th cycle with 83% capacity retention.

• Journal of the Korean Society of Safety
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• v.39 no.2
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• pp.38-43
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• 2024

Recently, with the expanding market for electronic devices and electric vehicles, secondary battery usage has been on the rise. Lithium-ion batteries are particularly popular due to their fast charging times and lightweight nature compared to other types of batteries. A secondary battery consists of four components: anode, cathode, electrolyte, and separator. Generally, the positive and negative electrode materials of secondary batteries are composed of an active material, a binder, and a conductive material. Acetylene Black (AB) is utilized to enhance conductivity between active material particles or metal dust collectors, preventing the binder from acting as an insulator. However, when recycling waste batteries that have been subject to high usage, there is a risk of fire and explosion accidents, as accurately identifying the characteristics of Acetylene Black dust proves to be challenging. In this study, the lower explosion limit for Acetylene Black dust with an average particle size of 0.042 ㎛ was determined to be 153.64 mg/L using a Hartmann-type dust explosion device. Notably, the dust did not explode at values below 168 mg, rendering the lower explosion limit calculation unfeasible. Analysis of explosion delay times with varying electrode gaps revealed the shortest delay time at 3 mm, with a noticeable increase in delay times for gaps of 4 mm or greater. The findings offer fundamental data for fire and explosion prevention measures in Acetylene Black waste recycling processes via a predictive model for lower explosion limits and ignition delay time.

• Proceedings of the Materials Research Society of Korea Conference
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• 1999.11a
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• pp.196-196
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• 1999

• Proceedings of the Materials Research Society of Korea Conference
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• 1999.11a
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• pp.21-21
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• 1999

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• v.11 no.2
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• pp.294-301
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• 2006

• Proceedings of the Korean Ceranic Society Conference
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• 2004.04b
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• pp.49.1-49.1
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• 2004

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2004.11a
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• pp.106-106
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• 2004