• Title, Summary, Keyword: Lithium Secondary Battery

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Analysis of the Secondary Battery Charge/Discharge System Using State Space Averaging Method (상태공간평균화법에 의한 2차전지 충방전 시스템의 해석)

  • Won, Hwa-Young;Chae, Soo-Yong;Lee, Hyoung-Ju;Kim, Hee-Sun;Hong, Soon-Chan
    • Proceedings of the KIPE Conference
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    • pp.13-15
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    • 2008
  • Charging or discharging secondary batteries such as a lithium-ion battery is essential in the stage of production and takes long time over two hours. And the charge/discharge system is operated with high switching frequency over several tens kHz. Therefore, to simulate such a system in the conventional way takes very long time and huge files are produced. Finally, the simulation would be unable with general PC class. In this paper, the lithium-ion battery charge/discharge system is analyzed by using state space averaging method. As a result, the simulation time is reduced dramatically and the charge/- discharge characteristics of the lithium-ion battery can be observed.

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Carbon Material from Natural Sources as an Anode in Lithium Secondary Battery

  • Bhardwaj, Sunil;Sharon, Maheshwar;Ishihara, T.;Jayabhaye, Sandesh;Afre, Rakesh;Soga, T.;Sharon, Madhuri
    • Carbon letters
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    • v.8 no.4
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    • pp.285-291
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    • 2007
  • Carbon materials of various morphologies were synthesized by pyrolysis of Soap-nut seeds (Sapindus mukorossi), Jack Fruit seeds (Artocarpus heterophyllus), Date-seeds (Phoenix dactylifera), Neem seeds (Azadirachta indica), Tea leaves (Ehretia microphylla), Bamboo stem (Bambusa bambus) and Coconut fiber (Cocos nucifera), without using any catalyst. Carbon materials thus formed were characterized by SEM XRD and Raman. Carbon thus synthesized varied in size (in ${\mu}m$) but all showed highly porous morphology. These carbon materials were utilized as the anode in Lithium secondary battery. Amongst the various precursors, carbon fibers obtained from Soap-nut seeds (Sapindus mukorossi) and Bamboo stem (Bambusa bambus), even after $100^{th}$ cycles, showed the highest capacity of 130.29 mAh/g and 92.74 mAh/g respectively. Morphology, surface areas and porosity of carbon materials obtained from these precursors were analyzed to provide interpretation for their capacity to intercalate lithium. From the Raman studies it is concluded that graphitic nature of carbon materials assist in the intercalation of lithium. Size of cavity (or pore size of channels type structure) present in carbon materials were found to facilitate the intercalation of lithium.

In Situ X-ray Absorption Spectroscopic Study for α-MoO3 Electrode upon Discharge/Charge Reaction in Lithium Secondary Batteries

  • Kang, Joo-Hee;Paek, Seung-Min;Choy, Jin-Ho
    • Bulletin of the Korean Chemical Society
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    • v.31 no.12
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    • pp.3675-3678
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    • 2010
  • In-situ X-ray absorption spectroscopy (XAS) was used to elucidate the structural variation of $\alpha-MoO_3$ electrode upon discharge/charge reaction in a lithium ion battery. According to the XAS analysis, hexavalent Mo atoms in $\alpha-MoO_3$ framework are reduced as the amount of intercalated lithium ions increases. As lithium de-intercalation proceeds, most of pre-edge peaks are restored again. However, according to the Fourier transforms of the extended X-ray absorption fine structure (EXAFS) spectra, lithium de-intercalation reaction is partially irreversible upon the charge reaction, which is one of the main reasons why the capacity of $\alpha-MoO_3$ electrode decreases upon successive discharge/charge cycles.

A Study on Improvement of Storage Safety through Quality improvement of Torpedo Propulsion Battery (어뢰 추진전지 품질개선을 통한 저장안정성 향상에 관한 연구)

  • Jang, Min-Ki
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.7
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    • pp.291-298
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    • 2019
  • We describe the improvement of insulation performance and the prevention of electrolyte leakage in a single cell in order to prevent the fuming phenomenon caused by leakage of electrolyte in a lithium secondary battery in a submerged weapon (torpedo) operated in Korea. A torpedo using lithium secondary battery as a main power source (propulsion battery) can induce the heat and fuming phenomenon, which makes it inconvenient for naval equipment operation in Korea. In the simulation test, the electrolyte of some battery cells leaked in the battery pack unit, leading to a short circuit between the main power circuit and the terminal tab of the high voltage part. We analyzed the characteristics and mechanism of the lithium secondary battery during this heat generation and fuming phenomenon. In order to prevent leakage of the electrolyte in the lithium secondary battery, the design was improved via fundamental (terminal tap enhancement) and complementary (insulation block selection and installation) measures. Comparison of the performance test before and after the improvement showed that the tensile strength of the tap terminal was improved about 2 times and the withstand voltage characteristic was improved. The application of quality improvement measures resulted in no fuming even after more than 3 years of field operation. This result is expected to improve the operation and storage stability of the torpedo propulsion cell.

Charging/Discharging Modeling of Lithium Secondary Battery for Estimating Cycle Characteristic (리튬2차전지의 수명성능평가를 위한 충방전특성 모델링)

  • Kim, Jae-Eon;Rho, Dae-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.6
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    • pp.1343-1354
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    • 2007
  • Secondary batteries become more important in our lives as the use of portable electric devices, such as camera, cellular phone, laptop, etc. Especially, because of their high energy densities and high voltage, lithium-ion batteries are being used in many systems. For the optimum design of such systems which include lithium-ion batteries, virtual prototype is required generally. However, since the complex chemical and physical processes are involved, the behavior of battery becomes harder to be predicted compared with that of electric and mechanic devices. This paper, proposes a new static model of lithium secondary battery, which accounts for nonlinear equilibrium potentials, rate and temperature dependencies, thermal effects, lifetime characteristic. The results of the simulation of the model are analysed and compared with experimental data to inspect their validity.

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Fabrication of LiNiO2 using NiSO4 Recovered from NCM (Li[Ni,Co,Mn]O2) Secondary Battery Scraps and Its Electrochemical Properties (NCM(Li[Ni,Co,Mn]O2)계 폐 리튬이차전지로부터 NiSO4의 회수와 이를 이용한 LiNiO2 제조 및 전기화학적 특성)

  • Kwag, Yong-Gyu;Kim, Mi-So;Kim, Yoo-Young;Choi, Im-Sic;Park, Dong-Kyu;Ahn, In-Sup;Cho, Kwon-Koo
    • Journal of Korean Powder Metallurgy Institute
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    • v.21 no.4
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    • pp.286-293
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    • 2014
  • The electrochemical properties of cells assembled with the $LiNiO_2$ (LNO) recycled from cathode materials of waste lithium secondary batteries ($Li[Ni,Co,Mn]O_2$), were evaluated in this study. The leaching, neutralization and solvent extraction process were applied to produce high-purity $NiSO_4$ solution from waste lithium secondary batteries. High-purity NiO powder was then fabricated by the heat-treatment and mixing of the $NiSO_4$ solution and $H_2C_2O_4$. Finally, $LiNiO_2$ as a cathode material for lithium ion secondary batteries was synthesized by heat treatment and mixing of the NiO and $Li_2CO_3$ powders. We assembled the cells using the $LiNiO_2$ powders and evaluated the electrochemical properties. Subsequently, we evaluated the recycling possibility of the cathode materials for waste lithium secondary battery using the processes applied in this work.

Charge/discharge Properties of Flyash as a function of Electrolyte for Lithium Rechargeable Battery (전해질 종류에 따른 Flyash의 리튬 2차전지의 충방전 특성)

  • 송희웅;김종욱;이경섭;박복기;구할본
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.362-365
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    • 1999
  • The electrochemical properties of flyash obtained from combustion of fuel in fossil power plants and their performance as anode material of secondary battery have been investigated Various flysh pellets molded at various molding pressure have been used as anode lithium secondary battery. The best Performance was achieved when flyash pellet molded at pressure of 400kgf/$\textrm{cm}^2$ is utilized, that is, charge capacity of 300kgf/$\textrm{cm}^2$ and Coulombic efficiency of larger than 95% have been achieved. In addition, this battery exhibited good cycling performance. Considering these results, we predicted that utilization of the flyash as anode material and polyaniline conducting polymer as cathode material in a secondary will show capacity of 300mAh/g and Coulombic efficiency of higher than 95%.

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Separator Effect on the Cell Failure of Lithium Secondary Battery using Lithium Metal Electrode (리튬금속 전극을 이용한 리튬이차전지의 내부단락에 대한 분리막의 영향)

  • Kim, Ju-Seok;Bae, Sang-Ho;Hwang, Min-Ji;Heo, Min-Yeong;Doh, Chil-Hoon
    • Journal of the Korean Electrochemical Society
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    • v.14 no.3
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    • pp.171-175
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    • 2011
  • Lithium secondary batteries using lithium metal count electrode are easy to use and to analyze the specific characteristics of working electrode. Nevertheless, during the charge operation internal electrical short circuit could be caused by the dendritic growth of lithium. The cell failure by the short circuit depends on the condition of separator such as constitutive material and thickness. To prevent the cell failure caused by the dendritic growth of lithium, the electrochemical properties of the cell of lithium metal count electrode were evaluated for four different kinds of separator. Among the tested separators, GMF (glass micro-fiber filter, $300{\mu}m$) was the most promising one because it could effectively prevent the cell failure during the charge. The cell using GMF separator had relatively low impedance. Generally the cell using thicker separator than $50{\mu}m$ could effectively avoid the cell failure by internal short circuit and had the good cycleability. The highest rate capability by the signature method was acquired in the case of GMF separator.

The Electrochemical Characteristics of Surface-modified Carbonaceous Materials by tin Oxides and Copper for Lithium Secondary Batteries

  • Lee, Joong-Kee;Ryu, D.H.;Shul, Y.G.;Cho, B.W.;Park, D.
    • Carbon letters
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    • v.1 no.3_4
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    • pp.170-177
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    • 2001
  • Lithium intercalated carbon (LIC) are basically employed as an anode for currently commercialized lithium secondary batteries. However, there are still strong interests in modifying carbon surface of active materials of the anode because the amount of irreversible capacity, charge-discharge capacity and high rate capability are largely determined by the surface conditions of the carbon. In this study, the carbonaceous materials were coated with tin oxide and copper by fluidized-bed chemical vapor deposition (CVD) method and their coating effects on electrochemical characteristics were investigated. The electrode which coated with tin oxides gave the higher capacity than that of raw material. Their capacity decreased with the progress of cycling possibly due to severe volume changes. However, the cyclability was improved by coating with copper on the surface of the tin oxides coated carbonaceous materials, which plays an important role as an inactive matrix buffering volume changes. An impedance on passivation film was decreased as tin oxides contents and it resulted in the higher capacity.

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The Preparation of K-GIC and its Anodic Characteristics of Lithium Ion Secondary Battery (K-GIC의 합성 및 리튬이온이차전지에서의 부극특성)

  • Kim, Hyun-Joong;Lee, Chul-Tae
    • Applied Chemistry for Engineering
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    • v.9 no.5
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    • pp.786-790
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    • 1998
  • K-GIC of the new carbon electrode to improve performance of carbon negative electrode in lithium ion secondary battery was prepated and its electrical characteristics were studied. Form this study, intercalated K quantity was increased in order of $2>3>1mole/{\ell}$ of KCl solution. And, for KCl solution of 1mole, the mole ratio of carbon and potassium was 156~388 carbon/potassium. The proper condition of K-GIC preparation was KCl solution of $1mole/{\ell}$, reaction temperature of $700^{\circ}C$, reaction time of 1 hour. From this condition, the intercalation and deintercalation behavior of lithium was very excellent. Also the reversibility was excellent.

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