• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.733-736
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• 2001

Instead of a solution technigue producing amorphous LiV$_3$O$_{8}$ form, we prepared Lithium vanadate glass by melting Li$_2$O-P$_2$O$_{5}$-V$_2$O$_{5}$, composition in pt. crucible and by quenching on the copper plate. From the crystallization of Li$_2$O-P$_2$O$_{5}$-V$_2$O$_{5}$, we could abtain crystal phase, LiV$_3$O$_{8}$. The material heat-treated at lower-temperature, 25$0^{\circ}C$ was less crystalline, but had higher capacity. In present paper, we describe eletrochemical properties during crystallization process and find the best crystallization condition of Li$_2$O-P$_2$O$_{5}$-V$_2$O$_{5}$ glass as cathod material.cathod material.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.523-527
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• 2000

Vanadate glasses in the Li$_2$O-P$_2$O$_{5}$-V$_2$O$_{5}$ system containing 10mo1% glass former, P$_2$O$_{5}$ were prepared by melting the batch in pt. crucib1e followed by quenching on the copper plate. We found that Li$_2$O-P$_2$O$_{5}$-V$_2$O$_{5}$ glass-ceramics obtained from nucleation of glass showed significantly higher capacity and longer cycle life than conventionally made crystalline LiCoO$_2$, LiNiO$_2$and LiV$_3$O$_{8}$. In the present paper, We describe electro-chemical properties during crystallization process and find the best crystallization condition of Li$_2$O-P$_2$O$_{5}$-V$_2$O$_{5}$ g1ass as cathod material. Li$_2$O-P$_2$O$_{5}$-V$_2$O$_{5}$ glass-ceramics shows superior rechargeable capacity of 220 mAh/g in the cycling between 2.0 and 3.9V.etween 2.0 and 3.9V.

• Journal of Electrochemical Science and Technology
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• 제9권1호
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• pp.60-68
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• 2018

In aqueous rechargeable lithium ion batteries, $LiV_3O_8$ exhibits obviously enhanced electrochemical performance after $AlF_3$ surface modification owing to improved surface stability to fragile aqueous electrolyte. The cycle life of $LiV_3O_8$ is significantly enhanced by the presence of an $AlF_3$ coating at an optimal content of 1 wt.%. The results of powder X-ray diffraction, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, inductively coupled plasma-optical emission spectrometry, and galvanostatic charge-discharge measurements confirm that the electrochemical improvement can be attributed mainly to the presence of $AlF_3$ on the surface of $LiV_3O_8$. Furthermore, the $AlF_3$ coating significantly reduces vanadium ion dissolution and surface failure by stabilizing the surface of the $LiV_3O_8$ in an aqueous electrolyte solution. The results suggest that the $AlF_3$ coating can prevent the formation of unfavorable side reaction components and facilitate lithium ion diffusion, leading to reduced surface resistance and improved surface stability compared to bare $LiV_3O_8$ and affording enhanced electrochemical performance in aqueous electrolyte solutions.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 영호남학술대회 논문집
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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.

• E2M - 전기 전자와 첨단 소재
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• 제7권4호
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• pp.317-324
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• 1994

In this study, new preparation method of LiCoO$_{2}$ was applied to develop cathode active material for Li rechargeable cell, and followed by X-ray diffraction analysis, electrochemical properties and initial charge/discharge characteristics as function of current density. HC8A72- and CC9A24-LiCoO$_{2}$ were prepared by heating treatment of the mixture of LiOH H$_{2}$O/CoCO$_{3}$(1:1 mole ratio) and the mixture of Li$_{2}$CO$_{3}$/CoCO$_{3}$(1:2 mole ratio) at 850 and 900.deg. C, respectively. Two prepared LiCoO$_{2}$s were identified as same structure by X-ray diffraction analysis. a and c lattice constant were 2.816.angs. and 14.046.angs., respectively. The electrochemical potential of CFM-LiCoO$_{2}$(Cyprus Foote Mineral Co.'s product), HC8A72-LiCoO$_{2}$ and CC9A24 LiCoO$_{2}$ electrode were approximately between 3.32V and 3.42V vs. Li/Li reference electrode. Stable cycling behavior was obtained during the cyclic voltammetry of LiCoO$_{2}$ electrode. According as scan rate increases, cathodic capacity decreases, but redox coulombic efficiency was about 100% at potential range between 3.6V and 4.2V vs. Li/Li reference electrode. Cathodic capacity of HC8A72-LiCoO$_{2}$ was 32% higher than that of CFM-LiCoO$_{2}$ and that of CC9A24-LiCoO$_{2}$ was 47% lower than that of CFM-LiCoO$_{2}$ at 130th cycle in the condition of lmV/sec scan rate. Constant cur-rent charge/discharge characteristics of LiCoO$_{2}$/Li cell showed increasing Ah efficiency with initial charge/discharge cycle. Specific discharge capacities of CFM and HC8A72-LiCoO$_{2}$ cathode active materials were about 93mAh/g correspondent to 34% of theretical value, 110mAh/g correspondent to 40% of theretical value, respectively. In the view of reversibility, HC8A72-LiCoO$_{2}$ was also more excellent than CFM- and CC9A24-LiCoO$_{2}$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 춘계학술대회 논문집 전자세라믹스 센서 및 박막재료 반도체재료 일렉트렛트 및 응용기술
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• pp.157-159
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• 2000

Vanadate glass in the $Li_2O-P_2O_5-V_2O_5$ system with 60mol% $V_2O_5$ was prepared by melting the bath in pt. crucible followed by quenching on the copper plate. We found that $Li_2O-P_2O_5-V_2O_5$ glass ceramics obtained from nucleation of $Li_2O-P_2O_5-V_2O_5$ glass showed significantly 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 $Li_2O-P_2O_5-V_2O_5$ glass as cathode material. The Charge and discharge capacity of $Li_2O-P_2O_5-V_2O_5$ glass was about 220mAh/g for the cell heat-treated at $250^{\circ}C$ for 2.5hr.

• Nuclear Engineering and Technology
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• 제54권3호
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• pp.965-974
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• 2022

Platinum anodes are widely used for metal oxides reduction in LiCl-Li₂O, however high-cost and low-corrosion resistance hinder their implementation. NiO-Li₂O ceramics is an alternative corrosion resistant anode material. Anode processes on platinum and NiO-Li₂O ceramics were studied in (80 mol.%) LiCl-(20mol.%)KCl and (80 mol.%)LiCl-(20 mol.%)KCl-Li₂O melts by cyclic voltammetry, potentiostatic and galvanostatic electrolysis. Experiments performed in the LiCl-KCl melt without Li₂O illustrate that a Pt anode dissolution causes the Pt²⁺ ions formation at 3.14 V and 550℃ and at 3.04 V and 650℃. A two-stage Pt oxidation was observed in the melts with the Li₂O at 2.40 ÷ 2.43 V, which resulted in the Li₂PtO₃ formation. Oxygen current efficiency of the Pt anode at 2.8 V and 650℃ reached about 96%. The anode process on the NiO-Li₂O electrode in the LiCl-KCl melt without Li₂O proceeds at the potentials more positive than 3.1 V and results in the electrochemical decomposition of ceramic electrode to NiO and O₂. Oxygen current efficiency on NiO-Li₂O is close to 100%. The NiO-Li₂O ceramic anode demonstrated good electrochemical characteristics during the galvanostatic electrolysis at 0.25 A/cm² for 35 h and may be successfully used for pyrochemical treating of spent nuclear fuel.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.743-746
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• 2000

Metal-ferroelectric-insulator-semiconductor(MFIS) devices using Pt/$LiNbO_3$/Si structure were successfully fabricated. The dielectric constant of the AIN film calculated from the capacitance in the accumulation region in the capacitance-voltage(C-V) curve was about 8.2. The gate leakage current density of MIS devices using a aluminum electrode showed the least value of 1$\times$$1O^{-8}$A/$cm^2$ order at the electric field of 500kV/cm. The dielectric constant of $LiNbO_3$film on AIN/Si structure was about 23 derived from 1MHz capacitance-voltage (C-V) measurement and the resistivity of the film at the field of 500kV/cm was about 5.6$\times$ $1O^{13}$ $\Omega$.cm.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.58-61
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• 2001

Metal-insulator-semiconductor (MIS) C-V properties with high dielectric AIN thin films showed no hysteresis and good interface properties. The dielectric constant of the AIN film calculated from the capacitance at the accumulation region in the capacitance-voltage(C-V) characteristics was about 8. The C-V characteristics of MFIS capacitor showed a hysteresis loop due to the ferroelectric nature of the LiNbO$_3$ thin films. Typical dielectric constant value of LiNbO$_3$ film of MFIS device was about 23. The memory window width was about 1.2V at the gate voltage of $\pm$5 V ranges. Typical gate leakage current density of the MFIS structure was the order of 10$^{-9}$ A/cm$^2$ at the range of within $\pm$500 kV/cm. The ferroelectric capacitors showed no polarization degradation up to about 10$^{11}$ switching cycles when subjected to symmetric bipolar voltage pulse(peak-to-peak 8V, 50% duty cycle) in the 500kHz.

• 한국진공학회지
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• 제11권4호
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• pp.230-234
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• 2002

고온 급속 열처리를 행한 $LiNbO_3Si$/(100) 구조를 가지고 여러 가지 전극을 사용하여 금속/강유전체/반도체 커패시터를 제작하였으며, 제작한 커패시터의 비휘발성 메모리 응용 가능성을 확인하였다. MFS 커패시터의 C-V 특성 곡선에서는 LiNbO$_3$박막의 강유전성으로 인한 히스테리시스 특성이 관측되었으며, 1 MHz C-V 특성 곡선의 축적 영역에서 산출한 비유전율은 약 25 이었다. Pt 전극을 사용하여 제작한 커패시터에서는 인가 전계 500 kV/cm 범위에서 $1\times10^{-8}$ A/cm 이하의 우수한 누설전류 특성이 나타났다. midgap 부근에서의 계면 준위 밀도는 약 $10^{11}\textrm{cm}^2$.eV 이었으며, 잔류분극 값은 약 1.2 $\muC/\textrm{cm}^2$ 였다. Pt 전극과 A1 전극 모두 500 kHz 주파수의 바이폴러 펄스를 인가하면서 측정한 피로 특성에서 $10^{10}$ cycle 까지 측정된 잔류 분극 값이 초기 값과 같았다.