• 제목/요약/키워드: Lithium Secondary Battery

검색결과 358건 처리시간 0.024초

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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    • 제1권3_4호
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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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K-GIC의 합성 및 리튬이온이차전지에서의 부극특성 (The Preparation of K-GIC and its Anodic Characteristics of Lithium Ion Secondary Battery)

  • 김현중;이철태
    • 공업화학
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    • 제9권5호
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    • pp.786-790
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    • 1998
  • 리튬이온이차전지에 사용되는 탄소부극의 성능을 향상시키기 위하여 새로운 탄소부극으로서 K-GIC를 합성하여 전기화학적 특성을 조사하였다. K의 삽입량은 KCl 수용액의 농도가 $2>3>1mole/{\ell}$의 순으로 증가하였으며 $1mole/{\ell}$의 KCl 수용액으로 처리하였을 때 K와 C의 mole 비는 156~388 carbon/potassium이었다. K-GIC의 합성조건을 $1mole/{\ell}$ KCl 수용액으로 $700^{\circ}C$에서 1시간으로 처리하였을 때 가장 우수한 리튬의 삽입과 탈삽입 거동을 나타냈으며 가역성 또한 우수하였다.

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방전전압에 따른 리튬 이온 2차전지용 음극물질의 전기화학적 특성 (The electrochemical Characteristics on the Anode Material of Lithium Ion Secondary Batteries with Discharge Voltage)

  • 박종광;한태희;정동철;임성훈;한병성
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제49권6호
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    • pp.328-334
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    • 2000
  • A lithium ion secondary battery using carbon as a negative electrode has been developed. Further improvements to increase the cell capacity are expected by modifying the structure of the carbonaceous material. There are hopes for the development of large capacity lithium ion secondary batteries with long cycle, high energy density, high power density, and high energy efficiency. In the present paper, needle cokes from petroleum were examined as an anode of lithium ion secondary battery. Petroleum cokes, MCL(Molten Caustic Leaching) treated in Korea Institute Energy Research, were carbonized at various temperatures of 0, 500, 700, $19700^{\circ}C$ at heating rate of $2^{\circ}C$/min for lh. The electrolyte was used lM liPF6 EC/DEC (1:1). The voltage range of charge & discharge was 0.0V(0.05V) ~ 2.0V. The treated petroleum coke at $700^{\circ}C$ had an initial capacity over 560mAh.g which beyond the theoretical maximum capacity, 372mAh/g for LiC6. This phenomena suggests that carbon materials with disordered structure had higher cell capacity than that the graphitic carbon materials.

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리튬 2차 전지의 1차원 열적 특성을 고려한 임피던스예측 (Impedance Estimation for Lithium Secondary Battery According to 1D Thermal Modeling)

  • 이정수;임근욱;김광선;조현찬;유상길
    • 반도체디스플레이기술학회지
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    • 제7권2호
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    • pp.13-17
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    • 2008
  • In this paper, in order to get the characteristics of the lithium secondary cell, such as charge and discharge characteristic, temperature characteristic, self-discharge characteristic and the capacity recovery rate etc, we build a thermal model that estimate the impedance of battery by experiment & simulation. In this one-dimensional model, Seven governing equations are made to solve seven variables c, $c_s,\;\Phi_1,\;\Phi_2,\;i_2$, j and T. The thermal model parameters used in this model have been adjusted according to the experimental data measured in the laboratory. The result(Voc, Impedance) of this research can be used in BMS(Battery Management System), so an efficient method of using battery is developed.

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Electrochemical Properties of Coal Tar Pitch based MCMB

  • Suh, Jeong-Kwon;Hong, Ji-Sook;Lee, Jung-Min
    • Carbon letters
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    • 제5권3호
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    • pp.118-126
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    • 2004
  • MCMB (Mesocarbon microbeads) is a kind of anode material for lithium-ion secondary battery. MCMB charge/discharge cycle stability is one of the important criterion at lithium-ion battery operation. In this study, the cycling stability of a lithium-ion secondary battery has been examined. MCMB was made by the direct solvent extraction method. After the MCMB was carbonized and graphitized, the measurement of charge/discharge capacity and efficiency were carried out. In the result, discharge capacity of MCMB in the initial cycle was above 290.0 mAh/g. After the second cycle, efficiency of charge/discharge MCMB was about 98%. These results were similar to the commercial MCMB product.

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A Study on Optimal Operation Strategy for Mild Hybrid Electric Vehicle Based on Hybrid Energy Storage System

  • Bae, SunHo;Park, Jung-Wook
    • Journal of Electrical Engineering and Technology
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    • 제13권2호
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    • pp.631-636
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    • 2018
  • This paper proposed an optimal operation strategy for a hybrid energy storage system (HESS) with a lithium-ion battery and lead-acid battery for mild hybrid electric vehicles (mild HEVs). The proposed mild HEV system is targeted to mount the electric motor and the battery to a conventional internal combustion engine vehicle. Because the proposed mild HEV includes the motor and energy storage device of small capacity, the system focuses on low system cost and small size. To overcome these limitations, it is necessary to use a lead acid battery which is used for a vehicle. Thus, it is possible to use more energy using HESS with a lithium battery and a lead storage battery. The HESS, which combines the lithium-ion battery and the secondary battery in parallel, can achieve better performance by using the two types of energy storage systems with different characteristics. However, the system requires an operation strategy because accurate and selective control of the batteries for each situation is necessary. In this paper, an optimal operation strategy is proposed considering characteristics of each energy storage system, state-of-charge (SOC), bidirectional converters, the desired output power, and driving conditions in the mild HEV system. The performance of the proposed system is evaluated through several case studies with respect to energy capacity, SOC, battery characteristic, and system efficiency.

리튬이차전지용 고분전해질의 무기물의 첨가에 대한 영향 (The Effect of Inorganic Material in Polymer Electrolyte for Lithium Secondary Battery)

  • 박수길;박종은;이홍기;이주성
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 추계학술대회 논문집 학회본부 C
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    • pp.822-824
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    • 1998
  • The lithium polymer battery with polymer electrolyte is expected as a safe and long cycle life battery. This paper reports primarily the recent development results of a solid polymer electrolyte, which is a key point of the secondary battery system. The new type of polymer electrolyte was prepared under a dry Ar atmosphere by dissolving $LiCIO_4$ in a matrix of EC, PC and then dispersing polyacrylonitrile(PAN). Also adding some inorganic filler $Al_2O_3$. The dispersed solution heated at $120^{\circ}C$. The polymer electrolyte were characterized by EIS(Electrochemical Impedance Spectroscopy), TGA(Thermo Gravimetric analysis), DMA(Dynamic Mechanical Analyzer), DSC (Differential Scanning Calorimetry). The lithium ion yield is 0.29 when PAN-$Al_2O_3$ which was applied DC 5mV. The ionic conductivity of PAN, PAN-$Al_2O_3$ polymer electrolytes were showed $1.0{\times}10^{-4}S/cm$, $8.4{\times}10^{-4}S/cm$ at room temperature. When inorganic filler was added in the polymer electrolyte, ionic conductivity and lithium yield more larger than without inorganic filler.

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Novel Synthesis Method and Electrochemical Characteristics of Lithium Titanium Oxide as Anode Material for Lithium Secondary Battery

  • Kim Han-Joo;Park Soo-Gil
    • KIEE International Transactions on Electrophysics and Applications
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    • 제5C권3호
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    • pp.119-123
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    • 2005
  • Lithium titanium oxide as anode material for energy storage prepared by novel synthesis method. Li$_{4}$Ti$_{5}$O$_{12}$ based spinel-framework structures are of great interest material for lithium-ion batteries. We describe here Li$_{4}$Ti$_{5}$O$_{12}$ a zero-strain insertion material was prepared by novel sol-gel method and by high energy ball milling (HEBM) of precursor to from nanocrystalline phases. According to the X-ray diffraction and scanning electron microscopy analysis, uniformly distributed Li$_{4}$ Ti$_{5}$O$_{12}$ particles with grain sizes of 100nm were synthesized. Lithium cells, consisting of Li$_{4}$ Ti$_{5}$O$_{12}$ anode and lithium cathode showed the 173 mAh/g in the range of 1.0 $\~$ 3.0 V. Furthermore, the crystalline structure of Li$_{4}$ Ti$_{5}$O$_{12}$ didn't transform during the lithium intercalation and deintercalation process.

R.F. Magnetron Sputtering을 이용한 리튬이차전지 부극용 Sn1-xSixO2의 제조 및 특성 (Fabrication and Characterization of Sn1-xSixO2 Anode for Lithium Secondary Battery by R.F. Magnetron Sputtering Method)

  • 이상헌;박건태;손영국
    • 한국세라믹학회지
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    • 제39권4호
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    • pp.394-400
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    • 2002
  • 리튬 이차전지용 부극재료로 미량의 실리콘이 첨가된 주석산화물 박막을 R.F. magnetron sputtering법을 이용하여 제조하였다. 실리콘의 첨가로 인해 주석의 산화상태를 감소시켜서 첫 번째 충방전 동안 비가역성을 감소시키는 전기 화학적 결과를 얻을 수 있었다. 주석 산화물 박막의 결정 배향성은 기판온도가 올라감에 따라서 (110),(101),(211) 면들이 성장하였다. 합성된 박막은 기판온도가 $300^{\circ}C$이고 $Ar:O_2$의 비가 7:3일때, 700mAh/g의 에너지 밀도를 가지며 가장 좋은 가역성능을 보여주었다.

리튬 이차전지용 금속이 담지된 다공성 실리콘 음극물질의 전기화학적 특성 (Electrochemical Characteristics of Porous Modified Silicon Impregnated with Metal as Anode Materials for Lithium Secondary Batteries)

  • 장은정;전법주
    • 한국수소및신에너지학회논문집
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    • 제23권4호
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    • pp.353-363
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    • 2012
  • The relationship between the diffusivity and electrochemical characteristics of lithium secondary battery with the modified Si anode material prepared in HF/$AgNO_3$ solution was investigated. The crystallographic structure and images of the modified porous Si and modified Si/Cu was examined using the X-ray diffraction, BET and SEM. To examine the effect of metal composite and pore size distribution according to chemical etching on the electrochemical characterization, the electrodes for half cells were prepared with the modified Si, modified Si/Cu, and modified Si/Cu annealed with $600^{\circ}C$. Our results showed that the chemical diffusivity of lithium ions was related to structure and resistance of Si/Cu composite anode material. The lithium diffusivity in modified silicon compound calculated from the CV was at the range of $1{\times}10^{-12}$ to $9{\times}10^{-16}cm^2/s$. The effects of modified silicon structure and resistance on the cycling efficiency were significant.