• Title/Summary/Keyword: cathode material

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Re-synthesis and Electrochemical Characteristics of LiFePO4 Cathode Materials Recycled from Scrap Electrodes

  • Kim, Hyung Sun;Shin, Eun Jung
    • Bulletin of the Korean Chemical Society
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    • v.34 no.3
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    • pp.851-855
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    • 2013
  • This paper describes an environmentally friendly process for the recovery of $LiFePO_4$ cathode materials from scrap electrodes by a simple thermal treatment method. The active materials were easily separated from the aluminum substrate foil and polymeric binders were also decomposed at different temperatures ($400^{\circ}C$, $500^{\circ}C$, $600^{\circ}C$) for 30 min under nitrogen gas flow. The samples were characterized by X-ray diffraction (XRD), scanning electronic microscopy (SEM), Raman spectroscopy, Thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The electrochemical properties of the recycled $LiFePO_4$ cathode were evaluated by galvanostatic charge and discharge modes. The specific charge/discharge capacities of the recycled $LiFePO_4$ cathode were similar to those of the original $LiFePO_4$ cathode. The $LiFePO_4$ cathode material recovered at $500^{\circ}C$ exhibits a somewhat higher capacity than those of other recovered materials at high current rates. The recycled $LiFePO_4$ cathode also showed a good cycling performance.

Enhanced Cathode/Sulfide Electrolyte Interface Stability Using an Li2ZrO3 Coating for All-Solid-State Batteries

  • Lee, Jun Won;Park, Yong Joon
    • Journal of Electrochemical Science and Technology
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    • v.9 no.3
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    • pp.176-183
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    • 2018
  • In this study, a $Li_2ZrO_3$ coated $Li[Ni_{0.8}Co_{0.15}Al_{0.05}]O_2$ (NCA) cathode was applied to an all-solid-state cell employing a sulfide-based solid electrolyte. Sulfide-based solid electrolytes are preferable for all-solid-state cells because of their high ionic conductivity and good softness and elasticity. However, sulfides are very reactive with oxide cathodes, and this reduces the stability of the cathode/electrolyte interface of all-solid-state cells. $Li_2ZrO_3$ is expected to be a suitable coating material for the cathode because it can suppress the undesirable reactions at the cathode/sulfide electrolyte interface because of its good stability and high ionic conductivity. Cells employing $Li_2ZrO_3$ coated NCA showed superior capacity to those employing pristine NCA. Analysis by X-ray photoelectron spectroscopy and electron energy loss spectroscopy confirmed that the $Li_2ZrO_3$ coating layer suppresses the propagation of S and P into the cathode and the reaction between the cathode and the sulfide solid electrolyte. These results show that $Li_2ZrO_3$ coating is promising for reducing undesirable side reactions at the cathode/electrolyte interface of all-solid-state-cells.

Electrical and optical characteristics of Cold Cathode Fluorescence Lamp (냉음극 형광램프의 전기적 및 광학적 특성)

  • Kim, Soo-Yong;Jung, Won-Chae
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.11a
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    • pp.502-505
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    • 2002
  • 본 논문에서는 냉음극 형광램프의 구조 및 동작원리를 파악하고 램프의 특성을 알아본다. 램프의 특성에 영향을 주는 요소인 관경, 관길이, 가스압, 전극등을 최적화 하여야 하고 CCFL(cold cathode fluorescent lamp) 의 휘도가 관선류, 주파수, 가스압력, 주위온도에 의한 영향에 따른 전기적 및 광학적인 특성을 분석하고자 한다.

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Effect of Cathode Materials (MS2, M=Fe, Ni, Co) on Electrochemical Properties of Thermal Batteries (열전지용(MS2, M=Fe, Ni, Co)계 양극의 전기화학적 특성 연구)

  • Lee, Jungmin;Im, Chae-Nam;Yoon, Hyun-Ki;Cheong, Hae-Won
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.30 no.9
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    • pp.583-588
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    • 2017
  • Thermal batteries are used in military power sources that require robustness and long storage life for applications in missiles and torpedoes. $FeS_2$ powder is currently used as a cathode material because of its high specific energy density, environmental non-toxicity, and low cost. $MS_2$ (M = Fe, Ni, Co) cathodes have been explored as novel candidates for thermal batteries in many studies; however, the discharge characteristics (1, 2, 3 plateau) of single cells in thermal batteries with different cathodes have not been elucidated in detail. In this study, we independently analyzed the discharge voltage and calculated the total polarizations of single cells using $MS_2$ cathodes. Based on the results of this study, we propose $NiS_2$ as a potential cathode material for use in thermal batteries.

Charge-discharge behaviour of $LiNi_{0.85}Co_{0.15}O_2>/MPCF$ cell ($LiNi_{0.85}Co_{0.15}O_2/MPCF$전지의 충방전 특성)

  • 김상필;조정수;박정후;윤문수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1998.11a
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    • pp.25-28
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    • 1998
  • Lithiated cobalt and nickel oxides are becoming very attractive as active cathode materials for secondary lithium ion secondary battery. $LiCoO_2$ is easily synthesized from lithium cobalt salts, but has a relatively high oxidizing potential on charge. LiNiOz is synthesized by a more complex procedure and its nonstoichiometry significantly degraded the charge-discharge characteristics. But $LiNiO_2$ has a lower charge potential which increases the system stability. Lithiated cobalt and nickel oxides are iso-structure which make the preparation of solid solutions of $LiNi_{1-x}Co_xO_2$ for O$LiCoO_2 and LiNiO_2$ electrode. The aim of the presentb paper is to study the electrochemical behaviour, as weU as the possibilities for practical application of layered Iithiated nickel oxide stabilized by $Co^{3+}$ substitution as active cathode materials in lithium ion secondary battery.

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Chromium Poisoning of Neodymium Nickelate (Nd2NiO4) Cathodes for Solid Oxide Fuel Cells

  • Lee, Kyoung Jin;Chung, Jae Hun;Lee, Min Jin;Hwang, Hae Jin
    • Journal of the Korean Ceramic Society
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    • v.56 no.2
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    • pp.160-166
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    • 2019
  • In this study, we investigated the long-term stability of Nd2NiO4 solid oxide fuel cell (SOFC) cathodes to evaluate their chromium poisoning tolerance. Symmetrical cells consisting of Nd2NiO4 electrodes and a yttria-stabilized zirconia electrolyte were fabricated and the cell potential and polarization resistance were measured at 850 ℃ in the presence of gaseous chromium species for 800 h. Up to 500 h of operation, the cell potential remained constant at 500 mA/㎠. However, it increased slightly over the operation duration of 550-800 h. No appreciable increase was observed in the polarization resistance of the Nd2NiO4 cathode during the entire operation of 800 h. Physicochemical examinations revealed that the gaseous chromium species did not form chromium-related contamination not only in the Nd2NiO4 cathode but also at the cathode/electrolyte interface. The results demonstrated that Nd2NiO4 is resistant to chromium poisoning, and hence is a potential alternative to standard perovskite cathodes.

Synthesis of $LiCoO_2$ by solution route and its behaviour as a cathode material in lithium ion secondary battery (액상반응에 의해 합성한 $LiCoO_2$ 를 정극활물질로 이용한 Li ion 2차전지의 특성)

  • 김상필;조정수;박정후;심윤보;윤문수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1998.06a
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    • pp.143-146
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    • 1998
  • The $LiCoO_2$ powder was synthesized at >$700^{\circ}C$, >$850^{\circ}C$ by solution route. In this paper, we investigated X-ray diffraction, and charge-discharge performance for $LiCoO_2$/Li and $LiCoO_2$/MPCF cell. The $LiCoO_2$/Li ceSl exhibited a high avmge discharge potential of 38-3% and a good cycle life performance at 5(hnA/g during chargedischarge cycling between 43-3.0V. And, the $LiCoO_2$MPCF cell showed a high average discharge voltage of 3.6-3.W and a excellent cycle life prfomam during chargedischarge cycling b&wm 4 2-2.W. As a result, the $LiCoO_2$ powdm syd-eizd by solution route is a good cathode material for lithium ion secondary battery.

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Charge/discharge Properties of $Li_2O-P_2O-V_2O_5$ Glasses as a Cathode Material for Lithium Rechargeable Battery (리튬 이차전지의 정극 물질로서 $Li_2O-P_2O-V_2O_5$ 유리의 충방전 특성)

  • 송희웅;구할본;손명모;이헌수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.383-386
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    • 1999
  • The importance of rechargeable lithium cells has been emphasized. So a large variety of materials has been discovered and evaluated for use as reversible cathodes and electroyltes. This paper examines the charge/discharge properties and the charge/discharge cycling life of Li$_2$O-P$_2$O-V$_2$O$_{5}$Li cells. In audition, DTA tests were carried out on Li$_2$O-P$_2$O-V$_2$O$_{5}$ glass. As a result the best performance was achieved when 0.3Li$_2$O-0.1P$_2$O$_{5}$-0.6V$_2$O$_{5}$Li cells was mixed with SP270. that is discharge capacity of 240mAh/g have been achieved. In addition this battery exhibited good cycling performance. Considering these results we expected utilization of the Li$_2$O-P$_2$O-V$_2$O$_{5}$ glass as a cathode material in a secondary battery.y battery.

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New Design of Li[Ni0.8Co0.15Al0.05]O2 Nano-bush Structure as Cathode Material through Electrospinning

  • Nam, Yun-Chae;Lee, Seon-Jin;Kim, Hae-In;Son, Jong-Tae
    • Journal of the Korean Electrochemical Society
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    • v.24 no.1
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    • pp.1-6
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    • 2021
  • In this study, new morphology of NCA cathode material for lithium ion batteries was obtained through the electrospinning method. The prepared NCA nanofibers formed a nano-bush structure, and the primary particles were formed on the surface of the nanofibers. The embossing primary particles increased the surface area thus increasing the reactivity of lithium ions. The nano-bush structure could shorten the Li+ diffusion path and improve the Li+ diffusion coefficient. Scanning electron microscopy (SEM) revealed that the synthesized material consisted of nanofibers. The surface area of the nanofibers increased by primary particles was measured using atomic force microscopy (AFM). X-ray diffraction (XRD) analysis was carried out to determine the structure of the NCA nanofibers.