• 제목/요약/키워드: Lithium reduction

검색결과 226건 처리시간 0.022초

리튬이온배터리 음극활물질 Silicon/Carbon 복합소재의 전기화학적 특성 (Electrochemical Characteristics of Silicon/Carbon Composites for Anode Materials of Lithium Ion Batteries)

  • 박지용;정민지;이종대
    • 공업화학
    • /
    • 제26권1호
    • /
    • pp.80-85
    • /
    • 2015
  • 본 연구에서는 리튬이차전지의 음극활물질인 실리콘/탄소 복합소재를 제조하여 전기화학적 특성을 확인하였다. 실리콘/탄소 합성물은 마그네슘의 열 환원 반응을 통해 SBA-15 (Santa Barbara Amorphous material No. 15)를 제조한 후 페놀 수지의 탄화 과정을 통해 합성하였다. 실리콘/탄소를 음극으로 제조하여 충방전, 사이클, 순환전압전류, 임피던스 테스트를 통해 분석하였다. 실리콘에 코팅된 탄소는 전기 전도도를 향상시켜 Rct값을 235 ohm (silicon)에서 30 ohm (실리콘/탄소)으로 낮추었고 리튬의 탈 삽입 시에 발생하는 실리콘의 팽창을 억제하여 전극을 안정화시키는 효과를 보여주었다. 실리콘/탄소 전극을 사용한 리튬이차전지는 1,348 mAh/g의 용량을 나타내었고 50사이클 동안 76%의 안정성을 보여주었다.

sSn으로 캡슐화된 그라파이트 복합체의 리튬이온전지 부극 특성 (Electrochemical Properties of Tin-Encapsulated Graphite as Anode in Lithium-Ion Batteries)

  • 안중호
    • 한국분말재료학회지
    • /
    • 제10권1호
    • /
    • pp.21-25
    • /
    • 2003
  • The Sn - graphite composites were prepared by chemical encapsulation method for anode materials in Li-ion batteries. EDS and XRD analysis confirmed the presence of Sn in the graphite structure. Cyclic voltammometry (CV) measurement shows extra reduction and oxidation peaks, which might to be related to the formations of $Li_xSn$ alloy compounds. Graphite-tin composite electrodes demonstrated higher Lithium storage capacities than graphite electrodes. Due to the nature of fine Sn particles on graphite surface, the graphite-tin composite electrodes have shown a good cycle properties.

Effect of Nitrile-Functionalized Zwitterions on Electrochemical Properties of Electrolytes for Use in Lithium-ion Batteries

  • Lee, Bum-Jin;Kwak, Seung-Yeop
    • 한국재료학회:학술대회논문집
    • /
    • 한국재료학회 2012년도 춘계학술발표대회
    • /
    • pp.97.2-97.2
    • /
    • 2012
  • This study examined the utility of two zwitterions, nitrile-functionalized zwitterions and a zwitterion without a nitrile group (MF-ZI), were used as additives along with 1 M $LiPF_6$ in ethylene carbonate (EC):diethylene carbonate (DEC) (3:7 V/V) (E-0) to form an electrolyte solution for use in lithium ion batteries comprising graphite and $LiCoO_2$ electrodes. The presence of NF-ZI (E-NF-ZI) in the electrolyte produced an ion conductivity comparable to that of E-0 and higher than that of an electrolyte containing MF-ZI (E-MF-ZI). Linear sweep voltammetry data revealed that the intensity of the E-NF-ZI reduction peak was lower than that of E-0. Furthermore, the successful formation of an SEI layer in the E-NF-ZI over graphite was confirmed by cyclic voltammetry data. These results were attributed to the adsorption of NF-ZI on the electrode surface, as verified by differential capacity measurements.

  • PDF

The Polyaniline Electrode Doped with Li Salt and Protonic Acid in Lithium Secondary Battery

  • Ryu, Kwang-Sun;Kim, Kwang-Man;Hong, Young-Sik;Park, Yong-Joon;Jang, Soon-Ho
    • Bulletin of the Korean Chemical Society
    • /
    • 제23권8호
    • /
    • pp.1144-1148
    • /
    • 2002
  • We prepared the polyaniline (Pani) film and powder by chemical polymerization and doping with different dopants and also investigated the capability of Li//polyaniline cells after assembling. The oxidation/reduction potentials and electrochemical reaction of Li//polyaniline cells were tested by cyclic voltammetry technique. The Li//Pani-HCl cells with 10% and 20% conductors show a little larger specific discharge capacities than that without conductor. The highest discharge capacity of almost 50 mAh/g at 100th cycle is also achieved. However, Li//Pani-LiPF6 with 20% conductor shows a remarkable performance of ~90 mAh/g at 100th cycle. This is feasible value for using as the positive electrode material of lithium ion secondary batteries. It is also proved that the powder type electrode of Pani is better to use than the film type one to improve the specific discharge capacity and its stability with cycle.

은 담지한 혹연을 부극 활물질로 이용한 Li ion 2차전지의 전기화학적 특성 연구 (The Electrochemical properties of Lithium ion Secondary Battery using Ag-deposited graphite anode)

  • 김상필;조정수;박정후;윤문수
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 1998년도 춘계학술대회 논문집
    • /
    • pp.387-390
    • /
    • 1998
  • New Ag-deposited graphite anodes were developed using wet chemical reduction methods for depositing Ag metal onto graphite particles. In this paper, we investigated X-ray diffraction pattern and charge-discharge behavior for Ag-deposited graphite anode. The Lithium ion cello using Ag-deposited graphite anode showed a high average discharge voltage of 3.6∼3.W and a excellent cycle ability than that of conventional graphite. Little capacity loss in this battery may be due to the highly durable Ag-deposited graphite anodes.

  • PDF

Chemical and Electrochemical Intercalation of Lithium in 2D-FeMoO$_4Cl^1$

  • 조진호;장순호;노동윤;손경아
    • Bulletin of the Korean Chemical Society
    • /
    • 제10권1호
    • /
    • pp.27-30
    • /
    • 1989
  • Lithium has been intercalated into $FeMoO_4Cl$, and deintercalated from $LixFeMoO_4Cl$ both electrochemically and chemically. The inserted $Li^+$ ions are stabilized in the distorted octahedral field in interlayer space of $FeMoO_4Cl$. The crystal symmetry is reduced from tetragonal to monoclinic due to the reduction of ferric to ferrous ions in $LixFeMoO_4Cl$ upon lithium intercalation. From the magnetic and structural data, it has been concluded that the high-spin electronic configuration of $Fe^{2+}(d_{xz}^2{d_{y2}^1}{d_1}{2d_z^12}{\cdot}_y2)$, corresponding to $^5E_g$, group term in $D_{4h}$ symmetry, can be stabilized by the elongation of $FeO_4Cl_{2-}$octahedra in a weak ligand field.

수소화붕소리튬에 의한 선택환원. 수소화붕소리튬과 대표적 유기화합물과의 반응 (Selective Reduction with Lithium Borohydride. Reaction of Lithium Borohydride with Selected Organic Compounds Containing Representative Functional Groups)

  • 윤능민;차진순
    • 대한화학회지
    • /
    • 제21권2호
    • /
    • pp.108-120
    • /
    • 1977
  • 수소화붕소리튬-테트라히드로푸란용액의 환원특성에 대한 계통적인 연구가 52가지의 대표적인 작용기를 가진 유기화합물을 가지고 표준조건($0^{\circ}$, 테트라히드로 푸란)에서 대략의 반응속도 및 정량 관계를 알아봄으로서 이루어 졌다.

  • PDF