• Title/Summary/Keyword: LI5

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Synthesis of Defective-Structure Li4Mn5O12 by Combustion Method and Its Application to Hybrid Capacitor (연소합성법에 의한 결함구조 Li4Mn5O12제조와 하이브리드 커패시터 적용)

  • Kim, Hun-Uk;Sun, Yang-Kook;Lee, Bum-Suk;Jin, Chang-Soo;Shin, Kyoung-Hee
    • Journal of the Korean Electrochemical Society
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    • v.13 no.2
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    • pp.103-109
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    • 2010
  • $Li_4Mn_5O_{12}$ was synthesized by combustion method using $LiNO_3$, $Li(CH_3COO){\cdot}2H_2O$ and $Mn(CH_3COO)_2{\cdot}4H_2O$. $Li_4Mn_5O_{12}$ was obtained over $400^{\circ}C$, however, the sample calcined at $400^{\circ}C$ for any time was mixed phases of $Li_4Mn_5O_{12}$ and $Mn_2O_3$. $Li_4Mn_5O_{12}$ calcined at $400^{\circ}C$ for 5 h had larger first discharge capacity (41.5mAh/g) at 1C-rate for 3.7~4.4V than other calcined samples. Moreover, applying to hybrid capacitor, it had good discharge capacity (24.74 mAh/g or 10.46 mAh/cc) at 100 mA/g for 1~2.5 V and higher energy density (39Wh/kg or 16.49Wh/cc) at same condition.

For the Li Drifted Germanium Detector (Li drifted Ge 검출기에 관해서)

  • 함창식
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.4 no.2
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    • pp.16-21
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    • 1967
  • This report describes actual fabrication mehod of Li drifted Ge detector. The gamma-ray spectrum from Cl(n, r) reaction measured by this Li drifted Ge detector are also shown. Energy resolution(FWHM) of this Li drifted Ge detector is 4.5KeV at the 122KeV( ), and 10KeV a the 1333KeV( ) respectively.

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Measurement and Analysis on the Physical Properties of Multi Lithium Salts Solution in Absorption Heat-Pumps (흡수식냉난방기용 다성분 리튬염 작동매체의 증기압 및 용해도 측정)

  • Ju, Woo-Sung;Kim, Hee-Taik;Oh, Young-Sam;Baek, Young-Soon
    • Applied Chemistry for Engineering
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    • v.9 no.1
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    • pp.82-88
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    • 1998
  • In an effort to obtain high efficiency in air cooled absorption heat pump, a new working fluid has developed with the addition of $LiNO_3$ and LiCl to the conventional solution of $LiBr-H_2O$. The solubility and vapor pressure of the multicomponent salts solution developed in this work were measured and compared with the results of $LiBr-H_2O$ solution. It was observed that there exists an optimal molar ratio of the inorganic salts in terms of solubility. The molar ratio of LiBr, $LiNO_3$ and LiCl was found to be about 5:1 in the $LiBr-LiNO_3$ mixture, and in the case of $LiBr-LiNO_3-LiCl$ mixture, the molar ratio of LiBr, $LiNO_3$ and LiCl was found to be around 5:1:2. The vapor pressure of the multicomponent salts solution of the optimal molar ratio was increased with adding $LiNO_3$, while decreased with adding LiCl.

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Electrochemical Characteristics of Cr Added Li4Ti5O12 Prepared by Sol-gel Method (졸-겔법으로 합성한 Cr 첨가 Li4Ti5O12의 전기화학적 특성)

  • Kim, Sun-Ah;Cho, Woo-Ram;Jeong, Koo-Hyun;Cho, Byung-Won;Na, Byung-Ki
    • Journal of the Korean Electrochemical Society
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    • v.14 no.1
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    • pp.27-32
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    • 2011
  • The electorchemical properties of $Li_4Ti_5O_{12}$ added with Cr was tested. The addition or substitution of atoms to $Li_4Ti_5O_{12}$ are expected to modify the crystal structure, and therefore to change the electrochemical performances of $Li_4Ti_5O_{12}$. After the spinel structure $Li_4Ti_{5-x}Cr_xO_{12}$ (x = 0~0.2) were obtained via sol-gel method, the gel was heated in a muffle furnace at $800{\sim}850^{\circ}C$ for 12 h in air. The physical properties of the samples were characterized by TG-DTA, XRD, SEM, FT-IR, and the electrochemical properties were tested with battery cycler at 0.01~2.0 V range. The $Li_4Ti_5O_{12}$ exhibited 169.9 mAh/g at 1C and capacity recovery was 97.5% of the initial capacity at 0.1C. $Li_4Ti_{4.9}Cr_{0.1}O_{12}$ (Cr 1% added) showed best performance of 193.8 mAh/g at 1C and the capacity recovery was increased to 98.8% of the initial capacity at 0.1C.

Growth and Characterization of $K_3LiNb_6O_{17}$ Single Crystals

  • Tae Hoon Kim;Seong Hyun Kim;Min Su Jang;Jung Nam Kim;Ji Hyun Ro
    • The Korean Journal of Ceramics
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    • v.6 no.3
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    • pp.272-275
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    • 2000
  • Starting from the stoichiometric composition of $K_2$CO$_3$: Li$_2$CO$_3$: Nb$_2$O$_5$=3 : 2 : 5 with the mole ratio, $K_3$LiNb$_6$O$_17$ 17/ single crystals were grown using the Czochralski method. Although the starting melt composition corresponds to the $K_3$Li$_2$Nb$_5$O$_15$ crystals, the chemical composition of the as grown crystals appears to be $K_2.95$Li$_1.33$Nb$_6.17$O$_17$ or $K_2.60$Li$_1.17$Nb$_{5.44}$ 5.44/O$_{15}$ which relatively contain fewer Li ions than $K_3$Li$_2$Nb$_5$O$_15$ crystals. We investigated the influence of the deficiency of the Li ions in the tetragonal tungsten bronze structure through the measurements of DE loop, temperature dependent dielectric constant, differential thermal analysis and temperature dependent X-ray diffraction pattern.

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Crystallization properties of $LiO_2-P_2O_5-Bi_2O_3-V_2O_5$ Glass for cathod material (정극 재료용 $LiO_2-P_2O_5-Bi_2O_3-V_2O_5$ 유리의 결정화 특성)

  • Son, Myung-Mo;Lee, Heon-Su;Gu, Hal-Bon;Jeong, In-Seong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.05b
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    • pp.311-315
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    • 2000
  • Vanadate glass in the $LiO_2-P_2O_5-Bi_2O_3-V_2O_5$ system containing 10mol% glass fonner, $P_2O_5$ and $Bi_2O_3$ was prepared by melting the batch in pt. crucible followed by Quenching on the copper plate. We found that $LiO_2-P_2O_5-Bi_2O_3-V_2O_5$ glass-ceramics obtained from nucleation of glass showed signifieantly higher capacity and longer cycle life than conventionally made crystalline $LiV_3O_{8}$. In the present paper, we describe the charge / discharge properties during crystallization process and find the best crystallization condition of $LiO_2-P_2O_5-Bi_2O_3-V_2O_5$ glass as cathod material.

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Electrochemical Properties of $Li_{2}O-P_{2}O_{5}-V_{2}O_{5}$ Glass-ceramics for cathode Material (정극재료용 $Li_{2}O-P_{2}O_{5}-V_{2}O_{5}$계 결정화 유리의 전기화학적 특성)

  • 손명모;이헌수;김종욱;김윤선;구할본
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.8
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    • pp.652-657
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    • 2001
  • Vanadate glasses containing 10~20mol% glass former, P$_2$O$_{5}$ were prepared by melting the batch in platinum crucible and quenching on the copper plate. Li$_2$O-P$_2$O$_{5}$-V$_2$O$_{5}$ glass-ceramics having LiV$_3$O$_{8}$ were obtained by heat-treatment of this glass in crystallization temperature. The glass-ceramics showed singnificantly good capacity and long cycles life according to heating condition. In this paper, we described electrochemical properties during crystallization process and found the best crystallizaton condition of Li$_2$O-P$_2$O$_{5}$-V$_2$O$_{5}$ glass as cathode material. Li$_2$O-P$_2$O$_{5}$-V$_2$O$_{5}$ glass-ceramics heat-treated at 233$^{\circ}C$ for 3 hors showed good rechargeable capacity of 220mAh/g in the cycling range between 2.0 and 3.9V.en 2.0 and 3.9V.

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Electron Magnetic Resonance Study of Paramagnetic Impurities in LiTaO3 and LiMbO3 Single Crystals (LiTaO3 및 LiMbO3 단결정 내의 상자성 불순물에 관한 전자 자기공명 연구)

  • Yeom, Tae-Ho
    • Journal of the Korean Magnetics Society
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    • v.13 no.5
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    • pp.204-210
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    • 2003
  • Electron magnetic resonance (EMR) of paramagnetic Cr$^{3+}$, Mn$^{2+}$, and Fe$^{3+}$ impurity ions in ferroelectric LiNbO$_3$ and LiTaO$_3$ single crystals has been studied. The actual sites location of paramagnetic impurity ions in the crystals was suggested from the experimental results and zero field splitting parameters calculated by superposition model. It turns out that Cr$^{3+}$ ions in LiNbO$_3$ crystal have two resonance centers and enter both the Li$^{+}$ and Nb$^{5+}$ ions. Mn$^{2+}$ and Fe$^{3+}$ impurity ions in LiNbO$_3$ substitute for Nb$^{5+}$ ions. However, both Cr$^{3+}$ and Fe$^{3+}$ ions in LiTaO$_3$ crystal reside at Li$^{+}$ ions.$ +/ ions.+/ ions.