• Title, Summary, Keyword: Lithium Dendrite

Search Result 15, Processing Time 0.039 seconds

Charge-Discharge Characteristics of Lithium Metal Polymer Battery Adopting PVdF-HFP/(SiO2, TiO2) Polymer Electrolytes Prepared by Phase Inversion Technique (상반전 기법으로 제조한 PVdF-HFP/(SiO2, TiO2) 고분자 전해질을 채용한 리튬금속 고분자 2차전지의 충방전 특성)

  • Kim, Jin-Chul;Kim, Kwang-Man
    • Korean Chemical Engineering Research
    • /
    • v.46 no.1
    • /
    • pp.131-136
    • /
    • 2008
  • Silica- or titania-filled poly (vinylidene fluoride-co-hexafluoropropylene)-based polymer electrolytes were prepared by phase inversion technique using N-methyl-2-pyrrolidone and dimethyl acetamide as solvent and water as non-solvent. The polymer electrolytes were adopted to the lithium metal polymer battery using high-capacity cathode $Li[Ni_{0.15}Co_{0.10}Li_{0.20}Mn_{0.55}]O_2$ and lithium metal anode. After the repeated charge-discharge test for the cell, it was proved that the cell adopting the polymer electrolyte based on the phase-inversion membrane containing 40~50 wt% silica showed the highest discharge capacity (180 mAh/g) until 80th cycle and then abrupt capacity fade was just followed. The capacity fade might be due to the deposition of lithium dendrite on the polymer electrolyte, in which the capacity retention was no longer sustainable.

Comparison of Characteristics of Electrodeposited Lithium Electrodes Under Various Electroplating Conditions (다양한 전착조건에서 제작된 리튬 전극의 특성 연구)

  • Lim, Rana;Lee, Minhee;Kim, Jeom-Soo
    • Journal of the Korean Electrochemical Society
    • /
    • v.22 no.3
    • /
    • pp.128-137
    • /
    • 2019
  • A lithium is the lightest metal on the earth. It has some attractive characteristics as a negative electrode material such as a low reduction potential (-3.04 V vs. SHE) and a high theoretical capacity ($3,860mAh\;g^{-1}$). Therefore, it has been studied as a next generation anode material for high energy lithium batteries. The thin lithium electrode is required to maximize the efficiency and energy density of the battery, but the physical roll-press method has a limitation in manufacturing thin lithium. In this study, thin lithium electrode was fabricated by electrodeposition under various conditions such as compositions of electrolytes and the current density. Deposited lithium showed strong relationship between process condition and its characteristics. The concentration of electrolyte affects to the shape of deposited lithium particle. As the concentration increases, the shape of particle changes from a sharp edged long one to a rounded lump. The former shape is favorable for suppressing dendrite formation and the elec-trode shows good stripping efficiency of 92.68% (3M LiFSI in DME, $0.4mA\;cm^{-2}$). The shape of deposited particle also affected by the applied current density. When the amount of current applied gets larger the shape changes to the sharp edged long one like the case of the low concentration electrolyte. The combination of salts and solvents, 1.5M LiFSI + 1.5M LiTFSI in DME : DOL [1 : 1 vol%] (Du-Co), was applied to the electrolyte for the lithium deposition. The lithium electrode obtained from this electrolyte composition shows the best stripping efficiency (97.26%) and the stable reversibility. This is presumed to be due to the stability of the surface film induced by the Li-F component and the DOL effect of providing film flexibility.

Polymer/Inorganic Nanohybrid Membrane on Lithium Metal Electrode: Effective Control of Surficial Growth of Lithium Layer and Its Improved Electrochemical Performance (리튬 금속 전극상 고분자/무기물 나노복합막 형성: 리튬층의 효과적 표면성장 제어 및 전기화학적 특성 향상)

  • Jeong, Yohan;Seok, Dohyeong;Lee, Sanghyun;Shin, Weon Ho;Sohn, Hiesang
    • Membrane Journal
    • /
    • v.30 no.1
    • /
    • pp.30-37
    • /
    • 2020
  • Polymer/inorganic composites were used as a protective layer of lihitum metal electrode for effective suppression of lithium dendrite. PVDF-HFP was used as an polymer material and TiO2 nanoparticle was used as an inorganic material. PVDF-HFP is a highly flexible polymer that acts as a matrix of inorganic materials while TiO2 nanoparticle improves the mechanical strength and ion conductivity of the protective layer. The as-synthesized protective hybrid membrane exhibited good dispersion of TiO2 in the PVDF-HFP matrix by SEM, AFM and XRD analyses. Furthermore, the electrochemical analysis showed that the polymer-inorganic composite retained high coulombic efficiency of 80% and low overpotential, less than 20 mV until the 100th cycles due to the improved mechanical properties and ion conductivity in comparison to the control sample (untreated and PVDF-HFP polymers/Cu).

Dependence of Thermal and Electrochemical Properties of ceramic Coated Separators on the Ceramic Particle Size (알루미나 크기에 따른 세라믹 코팅 분리막의 열적 특성 및 전기화학적 특성)

  • Park, Sun Min;Yu, Ho Jun;Kim, Kwang Hyun;Kang, Yun Chan;Cho, Won Il
    • Journal of the Korean Electrochemical Society
    • /
    • v.20 no.2
    • /
    • pp.27-33
    • /
    • 2017
  • Conventional lithium ion batteries suffer from notorious safety issues caused by inevitable lithium dendrite formation and proliferation during over/fast charging processes. The lithium dendrites or mechanical damage on the separator induce internal short circuit in LiB that generates extensive amount of heat within contacted electrode surfaces through the separator. During this heat generation, conventional polyolefin separators shrinks dramatically, and increasing short circuit pathway, that causes the battery to explode. To overcome this serious issue, ceramic coated separators are developed in commercial LiB to enhance thermal and mechanical stability. In this paper, various size(IL = 488.5 nm, I = 538.7 nm, S = 810.3 nm, D = 1533.3 nm) of $Al_2O_3$ particles are coated using styrene-butadiene rubber(SBR) / carboxymethyl cellulose(CMC) binder on PE separator to investigate its thermal stability and electrochemical effect on LiB coin cell with NCM cathode and Li metal anode.

Effects of UV irradiation on the crystalline phase with$Li_2O-Al_2O_3-SiO_2-K_2O$system ($Li_2O-Al_2O_3-SiO_2-K_2O$ 계어서의 UV조사 시간에 따른 결정상 생성에 관한 연구)

  • 이명원;강원호
    • Electrical & Electronic Materials
    • /
    • v.10 no.2
    • /
    • pp.166-171
    • /
    • 1997
  • The photomachinable glass-ceramics of Ag and CeO$_{2}$ added to Li$_{2}$O-Al$_{2}$O$_{3}$-SiO$_{2}$-K$_{2}$O glass system was investigated as a function of UV irradiation time. The temperature of optimum nucleation and crystal growth temperature were confirmed at 525.deg. C, 630.deg. C respectively using DTA and TMA. The phases of Li$_{2}$O.SiO$_{2}$ habit were lath-like and/or dendrite type and [002] direction of Li$_{2}$O.SiO$_{2}$ / Li$_{2}$O.2SiO$_{2}$ phases were changed according to the UV irradiation time by 400 W, 362 nm UV light source. Under that condition, the optimum UV irradiation time was 5 min.

  • PDF