• Membrane Journal
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• v.32 no.6
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• pp.401-410
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• 2022

Demand for lithium hydroxide (LiOH) is annually increasing due to its efficiency and safety for the environment in comparison to its current alternatives. Lithium can be found in different salty and brine lakes which later synthesized to produce LiOH for various applications. Different methods are used to separate and recover lithium ions, the most common of which is electrodialysis (ED). ED is a membrane-based separation technique which works on potential difference of its layers as a driving force to push ions from one side to another. The ion exchange membrane (IEM) in ED makes the process efficient because of the perm selectivity of different ions vary depending on their hydrodynamic volume. In this review, the different alteration strategies of both ED and IEM, to enhance the recovery of lithium ions are discussed.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.146-146
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• 2017

산화비스무트는 리튬이온과의 반응에서 현재 상용화된 그래파이트보다 높은 이론용량을 가지고 있으나, 리튬이온과의 반응에서 비교적 큰 부피팽창 특성을 가져 리튬이차전지의 음극재로서 상용화가 어려운 단점이 있다. 본 연구에서는, 이러한 문제점을 개선하기 위하여 양극산화법을 통해 충 방전시 부피팽창 변화가 매우 적은 타이타니아 나노튜브를 제조한 후, 그 위에 스프레이 방법으로 산화비스무트를 코팅하여 두 물질의 복함체를 만듦으로써 용량과 구조적 안정성을 향상시키는 방법을 소개한다. 음극재의 구조적 특성은 고분해능 주사전자현미경 (HR-SEM), 고분해능 엑스선 회절분석기(XRD)를 통해 조사하였으며, 전기화학 임피던스 분광법 (EIS), 순환전류법 (CV), 충 방전 싸이클 분석을 통해 리튬이차전지의 작동원리와 보다 향상된 성능을 규명하였다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.147-148
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• 2014

1990년에 Sony사는 탄소 음극과 리튬 코발트 산화물($LiCoO_2$) 양극을 함유하는 최초의 상용 리튬이온 전지를 발표하였다. 이후, 전지 성분을 변형하여 안전성과 전기화학적 용량을 향상시키고 비용을 줄이기 위한 연구가 수행되었다. 이러한 관심의 대부분은 양극 용량이 전지 용량을 한정하고 전지 비용의 40%까지 양극 원재료 비용에서부터 비롯되었기 때문에 양극 대체기술 개발에 집중되었다. 리튬이온 전지는 현재 휴대용 전자 기기 시장을 좌우하고 있다. 또한 온실가스 배출의 감소를 요구하는 환경보호에 대한 관심에 대한 새로운 시장 기회가 조성되었다. 1990년대 이후, 비독성의 저가 재료를 사용하여 환경 영향과 비용을 최소화 하려는 노력을 경주하면서 에너지 밀도를 극대화하고, 리튬 삽입과 추출의 유용 범위를 확대하여 용량을 극대화하고 있다.

• Journal of the Society of Disaster Information
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• v.16 no.2
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• pp.392-401
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• 2020

Purpose: This study analyzes the operating characteristics of a lithium ion capacitor that can be used as a standby power supply in an emergency, and determines whether the standby power supply is abnormal even by measuring the voltage using a linear proportionality characteristic during charging and discharging. The aim is to provide an experimental basis that can be done. Method: As a method for this study, first, analyze the operation principle and characteristics of the existing backup power supply and lithium ion capacitor, and then measure the voltage of the lithium ion capacitor according to the configuration and system block diagram of the induction lamp used in the experiment. We proceed with the test of the measured value of discharge power for each voltage band to check the amount of power held by the battery and the operation test experiment using induction lamps. Results: Just by checking the charging voltage using the linear proportional characteristics of lithium ion capacitors, it provides a basis for accurately inferring the effective operating time of induction lamp lamps. Conclusion: In the event of a disaster, the lithium ion capacitor is used as a spare power supply for emergency induction lamps to prevent complete discharge of emergency induction lamps, to prevent the problem of performing normal operation of the standby power supply, and to use only a simple voltage measurement to reserve power. It was intended to suggest many uses for evacuation equipment application in the future by making it possible to check whether the device is abnormal.

• Membrane Journal
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• v.30 no.4
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• pp.228-241
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• 2020

Separators, which produces physical layer between a cathode and anode, are getting enormous attention as the quality of the separator determines the performance of lithium ion batteries (LIBs). Porous membranes based on polyethylene (PE) and polypropylene (PP) are generally utilized as the separator of LIBs because of their high electrochemical stability and suitable mechanical strength. However, low thermal resistance and wettability of PE and PP membranes limited the potential of LIBs. Operating at the temperature exceeding the melting point of membranes, the separators change their structures which lead to short circuit of LIBs. Low wettability of the separators corresponds to low ionic conductivity which increases the cell resistance. To overcome these weaknesses of PE and PP separators, different types of separator were prepared by co-electrospinning, applying coating layer, forming core shell around membrane, and papermaking method. The synthesized separator greatly enhanced the heat resistance and wettability of separator and mechanical properties like flexibility and tensile strength. In this review different type of polymer membrane used as separator in lithium ion battery are discussed.

• 한국전기화학회:학술대회논문집
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• 1999.11a
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• pp.67-81
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• 1999

• 방재와보험
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• s.143
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• pp.30-35
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• 2011

• Applied Chemistry for Engineering
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• v.25 no.1
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• pp.1-13
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• 2014

Lithium ion batteries (LIBs) are the state-of-the-art technology among electrochemical energy storage and conversion cells, and are still considered the most attractive class of battery in the future due to their high specific energy density, high efficiency, and long cycle life. Rapid development of power-hungry commercial electronics and large-scale energy storage applications (e.g. off-peak electrical energy storage), however, requires novel anode materials that have higher energy densities to replace conventional graphite electrodes. Germanium (Ge) and silicon (Si) are thought to be ideal prospect candidates for next generation LIB anodes due to their extremely high theoretical energy capacities. For instance, Ge offers relatively lower volume change during cycling, better Li insertion/extraction kinetics, and higher electronic conductivity than Si. In this focused review, we briefly describe the basic concepts of LIBs and then look at the characteristics of ideal anode materials that can provide greatly improved electrochemical performance, including high capacity, better cycling behavior, and rate capability. We then discuss how, in the future, Ge anode materials (Ge and Ge oxides, Ge-carbon composites, and other Ge-based composites) could increase the capacity of today's Li batteries. In recent years, considerable efforts have been made to fulfill the requirements of excellent anode materials, especially using these materials at the nanoscale. This article shall serve as a handy reference, as well as starting point, for future research related to high capacity LIB anodes, especially based on semiconductor Ge and Si.

• Resources Recycling
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• v.29 no.6
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• pp.27-34
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• 2020

In order to remove sulfate(SO42-) and purify the Li2CO3, dissolution and recrystallization of crude Li2CO3 using distilled water and HCl solution was performed. When Li2CO3 was dissolved using distilled water, the amount of dissolved Li2CO3(wt.%) increased as the solution temperature decrease and showed about 1.50 wt.% at 2.5℃. In addition, when Na2CO3 was added and the Li2CO3 solution was recrystallized, the recrystallization(%) increased with increasing temperature, resulting in a 49.00 % at 95 ℃. On the other hand, when Li2CO3 was dissolved using HCl solution, there was no effect of reaction temperature. As the concentration of HCl solution increased, the amount of dissolved Li2CO3(wt.%) increased, indicating 7.10 wt.% in 2.0 M HCl solution. When the LiCl solution was recrystallized by adding Na2CO3, it exhibited a recrystallization(%) of 86.10 % at a reaction temperature of 70 ℃, and showed a sulfate ion removal(%) of 96.50 % or more. Finally, more than 99.10 % of Na and more than 99.90 % of sulfate were removed from the recrystallized Li2CO3 powder through water washing, and purified Li2CO3 with a purity of 99.10 % could be recovered.

• Journal of the Korean Electrochemical Society
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• v.24 no.4
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• pp.77-92
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• 2021

The energy density of lithium-ion batteries (LIBs) determines the mileage of electric vehicles. For increasing the energy density of LIBs, it is necessary to develop high-capacity active materials that can store more lithium ions within constrained weight. The rapid progress made in cathode technology has realized the utilization of the near-theoretical capacity of cathode materials. In contrast, commercial LIBs have still exploited graphite as active material in anodes since the 1990s. The most promising way to increase anodes' capacity is to mix high-capacity and long-cycle-life silicon oxides (SiOx) with graphite. However, the low initial Coulombic efficiency (ICE) of SiOx limits its content below 15 wt%, impeding the capacity increase in anodes. To address this issue, various prelithiation techniques have been proposed, which can improve the ICE of high-capacity anode materials. In this review paper, we introduce the principles and expected effects of prelithiation techniques reported so far. According to the reaction mechanisms, the strategies are categorized. Mainly, we focus on the recent progress of solution-based chemical prelithiation methods with commercial viability, of which lithiation reaction occurs homogeneously at liquid-solid interfaces. We believe that developing a cost-effective and mass-scalable prelithiation process holds the key to dominating the anode market for next-generation LIBs.