• Title, Summary, Keyword: Lithium Secondary Battery

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Performance of Graphite Electrode Modified with Acid Treatment for Lithium Ion Secondary Battery (산처리에 의해 개질된 리튬이온 이차전지용 흑연 전극의 특성)

  • Kim, Myung-Soo;Moon, Seung-Hwan;Kim, Mun-Geol;Kim, Taek-Rae;Hahm, Hyun-Sik;Park, Hong-Soo
    • Journal of the Korean Applied Science and Technology
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    • v.22 no.2
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    • pp.142-150
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    • 2005
  • The natural graphite particles A and heat-treated graphite particles B at $1800\;^{\circ}C$ after pitch-coating were used as the anode base materials for lithium ion secondary battery. In order to improve the performance of anode materials, the base anode materials were treated with various acids. With the acid treatments of 62% $HNO_3$ and 95% $H_2SO_4$ aqueous solution, the specific surface area and electrical conductivity of base anode materials were increased, and the initial charge-discharge capacity and cycle performance were improved due to the elimination of structural defects.

Performance of modified graphite as anode material for lithium-ion secondary battery

  • Zheng, Hua;Kim, Myung-Soo
    • Carbon letters
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    • v.12 no.4
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    • pp.243-248
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    • 2011
  • Two different types of graphite, such as flake graphite (FG) and spherical graphite (SG), were used as anode materials for a lithium-ion secondary battery in order to investigate their electrochemical performance. The FG particles were prepared by pulverizing natural graphite with a planetary mill. The SG particles were treated by immersing them in acid solutions or mixing them with various carbon additives. With a longer milling time, the particle size of the FG decreased. Since smaller particles allow more exposure of the edge planes toward the electrolyte, it could be possible for the FG anodes with longer milling time to deliver high reversible capacity; however, their initial efficiency was found to have decreased. The initial efficiency of SG anodes with acid treatments was about 90%, showing an over 20% higher value than that of FG anodes. With acid treatment, the discharge rate capability and the initial efficiency improved slightly. The electrochemical properties of the SG anodes improved slightly with carbon additives such as acetylene black (AB), Super P, Ketjen black, and carbon nanotubes. Furthermore, the cyclability was much improved due to the effect of the conductive bridge made by carbon additives such as AB and Super P.

A Study on the Improvement of the Thermal Stability of PE Separator for Lithium Secondary Battery Application Using Poly(meta-phenylene isophthalamide) (Poly(meta-phenylene isophthalamide)를 이용한 리튬이차전지용 PE 분리막의 고내열화 연구)

  • Park, Mina;Ra, Byung Ho;Bae, Jin-Young;Kim, Byung-Hyun;Choi, Won-Kun
    • Polymer(Korea)
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    • v.37 no.1
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    • pp.22-27
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    • 2013
  • In this study, we prepared separators with improved thermal stability by coating microporous polyethylene (PE) film for lithium secondary battery using poly(meta-phenylene isophthalamide) (Nomex). The mechanical and thermal properties of prepared separators were evaluated by thermal stability test and TMA as a function of the Nomex concentration and coating parameters. The corresponding coated PE separator showed better thermal and mechanical properties than the original PE separator. Electrochemical properties were also assessed by ionic conductivity, cyclic voltammetry and charge/discharge cycle.

Performance of the Negative Carbon Electrode Prepared with Graphitic Carbon and Nongraphitic Carbon Material in Lithium Ion Secondary Battery (흑연계 및 비흑연계 탄소로 조합된 리튬이온 이차전지의 탄소부극 특성)

  • Kim, Hyun-Joong;Lee, Chul-Tae
    • Applied Chemistry for Engineering
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    • v.9 no.7
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    • pp.1065-1069
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    • 1998
  • This study was investigated to improve peformance of carbon negative electrode for lithium ion secondary battery. The carbon electrode was prepared by mixing with graphitic carbon material, natural graphite, and nongraphitic carbon material, petroleum cokes, which was heat-treated at $700^{\circ}C$ for l hour. Its electrochemical and charge-discharge characteristics were tested according to mixing ratio of different two types of carbon material. The carbon electrode prepared with various mixing ratio showed both charateristcs of two different types of carbon materials and the best characteristics as carbon electrode was demonstrated at mixing ratio of 1:1.

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Fabrication of Carbon Nanofiber/Graphite Electrodes for Lithium Ion Secondary Battery (리튬이온 2차전지용 탄소나노섬유/흑연 복합재 전극의 제조)

  • Kwon, kyong-Hee;Moon, Seung-Hwan;Kim, Myung-Chan;Oh, Se-Min;Kim, Myung-Soo
    • Journal of the Korean Applied Science and Technology
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    • v.20 no.2
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    • pp.130-140
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    • 2003
  • In order to improve the lithium ion battery's performance, the carbon nanofibers were introduced to the anode electrode fabricated with natural graphite particles. The influence of structural adjustment of the particles by the introduction method of carbon nanofibers and the content of carbon nanofibers on the electrical property and charge/discharge characteristics of the electrode were investigated. The electrode fabricated with the mixture of 10 wt% of carbon nanofibers grown separately and 90 wt% of graphite particles showed an excellent discharge capacity of 400 mAh/g and the improved cycle performance. The improved performance could be explained by that the carbon nanofibers shortened and uniformly distributed on the surface of graphite particles by ball milling increased the stability for the intercalation/deintercalation of lithium ion and increased the electrical conductivity due to the closed packing between graphite particles.

A Review on Electrochemical Model for Predicting the Performance of Lithium Secondary Battery (리튬이차전지 성능 모사를 위한 전기화학적 모델링)

  • Yang, Seungwon;Kim, Nayeon;Kim, Eunsae;Lim, Minhong;Park, Joonam;Song, Jihun;Park, Sunho;Appiah, Williams Agyei;Ryou, Myung-Hyun;Lee, Yong Min
    • Journal of the Korean Electrochemical Society
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    • v.22 no.1
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    • pp.43-52
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    • 2019
  • As the application area of lithium secondary batteries becomes wider, performance characterization becomes difficult as well as diverse. To address this issue, battery manufacturers have to evaluate many batteries for a longer period, recruit many researchers and continuously introduce expensive equipment. Simulation techniques based on battery modeling are being introduced to solve such difficulties. Various lithium secondary battery modeling techniques have been reported so far and optimal techniques have been selected and utilized according to their purpose. In this review, the electrochemical modeling based on the Newman model is described in detail. Particularly, we will explain the physical meaning of each equation included in the model; the Butler-Volmer equation, which represents the rate of electrode reaction, the material and charge balance equations for each phase (solid and liquid), and the energy balance. Moreover, simple modeling processes and results based on COMSOL Multiphysics 5.3a will be provided and discussed.

Development of High Performance Battery for Navigation Aid's Power (항로표지(등부표) 전원공급용 고성능 축전지 개발)

  • Yoon, Seok-Jun;Cho, Myung-Hun;Lee, Dae-Pyo
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • pp.435-438
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    • 2009
  • A navigation aid buoy is a kind of safety facility for maritime navigation with a purpose of leading the vessels for navigating, docking and sail off. An advanced rechargeable battery is required for stable power supply for navigation aid buoy as the high magnitude LED lamps, real time location/control for navigation aids and e-Navigation support systems with maritime climate observation equipments have recently been deployed. This study is focused on the lithium battery, especially lithium polymer battery which is believed to be safer than the other types of batteries. The lithium polymer battery reviewed in this study is designed with $LiFePO_4$-based cathode, which has superior safety features to the oxide-based cathodes. Besides, a 3.6kWh battery pack has been built with the above-mentioned unit cells for the purpose of comparative research with lead acid battery system.

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Preparation and Characterization of $Fe_3O_4$/MWNTs Composites (산화철이 혼입된 다중벽탄소나노튜브 복합체의 제조 및 특성)

  • Park, Soo-Jin;Kim, Young-Ha
    • 한국신재생에너지학회:학술대회논문집
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    • pp.406-409
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    • 2009
  • In this work, the magnetite ($Fe_3O_4$)/multi-walled carbon nanotubes (MWNTs) composites for lithium secondary battery were prepared. Nano-$Fe_3O_4$ was deposited by chemical coprecipitation of $Fe^{2+}$ and $Fe^{3+}$ in the presence of MWNTs in alkaline solutions. Transmission electron spectroscopy (TEM) and X-ray diffraction (XRD) analyses indicated that nano-$Fe_3O_4$ particles had a good crystallinity of cubic specimens and many tiny particles attached on the surfaces of the MWNTs. The electrochemical properties of $Fe_3O_4$/MWNTs composites as anodes in lithium-secondary batteries were evaluated by cyclic voltammetry and galvanostatic charge/discharge techniques. The as-prepared $Fe_3O_4$/MWNTs composites showed an initial lithium storage capacity of 1120 mAh/g and a reversible capacity of 394 mAh/g after 100 cycles, demonstrating better performance than that of the commercial graphite anode materials.

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