• Title/Summary/Keyword: Anodes

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Efficient Organic Light-emitting Diodes with Aluminum-doped Zinc Oxide Anodes (알루미늄 도핑된 산화아연 양극을 적용한 고효율 유기발광다이오드)

  • Lee, Ho-Nyeon;Lee, Young-Gu;Jung, Jong-Guk;Lee, Seung-Eui;Oh, Tae-Sik
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.8
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    • pp.711-715
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    • 2007
  • Properties of organic light-emitting diodes (OLEDs) with aluminum-doped zinc oxide (ZnO:Al) anodes showed different behaviors from OLEDs with indium tin oxide (ITO) anodes according to driving conditions. OLEDs with ITO anodes gave higher current density and luminance in lower voltage region and better EL and power efficiency under lower current density conditions, However, OLEDs with ZnO:Al anodes gave higher current density and luminance in higher voltage region over about 8V and better EL and power efficiency under higher current density over $200mA/cm^2$. These seemed to be due to the differences in conduction properties of semiconducting ZnO:Al and metallic ITO. OLEDs with ZnO:Al anodes showed nearly saturated efficiency under high current driving conditions compared with those of OLEDs with ITO anodes. This meant better charge balance in OLEDs with ZnO:Al anodes. These properties of OLEDs with ZnO:Al anodes are useful in making bright display devices with efficiency.

Influence of Ca-Si Addition on Anodic Polarization Chgaraqcteristics of Al-Zn-In Anodes (海水中 Al-Zn-In 合金陽極의 分極特性에 미치는 Ca-Si 添加의 影響)

  • Seo, Chang-Je
    • Journal of the Korean institute of surface engineering
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    • v.12 no.1
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    • pp.3-10
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    • 1979
  • Many excellent Al-Zn-In anode have been developed up to the present. But for the purpose of the better performance of Al-Zn-In anodes in sea water the effect of calcium silicon addition on anodic polarization and current capacity of Al-Zn-In anodes was measured and analysed in sea water and artificial sea water. The results and conclusions obtained are summarized as follows. 1) Being compared with Al-Zn-In anodes, Al-Zn-In anodes containing 0.05% calcium silicon had superior characteristics in both anodic polarization and current capacity. 2) Corrosion patterns of the anodes containing calcium silicon were much more uniform than those of Al-Zn-In anodes. 3) In this experiment the most useful anode was Al-4% Zn-0.03% In-0.05% (Ca-Si). It had a capacity of 2.60Amp-hr of current/g and a voltage of 1.13(SCE reference) at anodic current density 1,000 4{\mu}A/cm^2$.

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Effects of Aluminum and Silicon as Additive Materials for the Zinc Anode in Zn-Air Batteries

  • Lee, Yong-Seok;Ryu, Kwang-Sun
    • Journal of the Korean Electrochemical Society
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    • v.21 no.1
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    • pp.12-20
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    • 2018
  • To solve low cycle efficiency of the zinc anode in Zn-air batteries by corrosion, this study examined the effects of Al as a cathodic protection additive to Zn. The Al-mixed Zn anodes were produced by mixing Zn and Al powder (1, 2, and 3 wt. %). To compare the effects of the Al additive, Si was selected under the same conditions. The morphology and elemental composition of the additives in the Zn were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, and inductively coupled plasma - mass spectrometry. The anti-corrosion effects of the Al and Si-mixed Zn anodes were examined by linear polarization. Cyclic voltammetry and charge-discharge tests were conducted to evaluate the electrochemical performance of the Al and Si-mixed Zn anodes. As a result, the Al-mixed Zn anodes showed highest corrosion resistance and cycling performance. Among these, the 2 wt.% Al-mixed Zn anodes exhibited best electrochemical performance.

Lifetime of Insoluble Anode for Cathodic Protection on Concrete Construction

  • Sohn, Kicheon;Chang, Hyunyoung;Kim, Youngsik
    • Corrosion Science and Technology
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    • v.4 no.2
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    • pp.56-59
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    • 2005
  • In rebar concrete structure, the corrosion of rebar can arise the deterioration of concrete structure and may affect the safety of the whole system. Recently, several methods for corrosion protection have been used and are more important for concrete structure using the sand including chloride ion. Among several protections, electrical cathodic protection has been expected to be one of the most useful methods in corrosion protection for reinforcement of concrete structures. The anode for cathodic protection needs high current density, high corrosion resistance and low overvoltage. To fill up the special qualities, the insoluble anodes were developed and these anodes were coated with metal oxide of $TiO_2$, $ZrO_2$, $RuO_2$, and $IrO_2$. Lifetime of these anodes can be one of the important factors affecting the lifetime of concrete structure in cathodic protection. In this work, several anodes were made by sol-gel method and thermal decomposition method and the lifetime of these anodes was evaluated by NACE international standard test method, TM 0294-94. Also, we did analyze the properties of coated metal oxides.

Fabrication of LaySr1-yFexTi1-xO3-based Nanocomposite Solid Oxide Fuel Cell Anodes by Infiltration (Infiltration법을 이용한 LaySr1-yFexTi1-xO3계 나노복합 연료극 제조)

  • Yoon, Jong-Seol;Choe, Yeong-Ju;Hwang, Hae-Jin
    • Journal of the Korean Ceramic Society
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    • v.51 no.3
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    • pp.224-230
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    • 2014
  • Nano-sized gadolinium-doped ceria (GDC)/nickel particle-dispersed $La_ySr_{1-y}Ti_{1-x}Fe_xO_3$ (LSFTO)-based composite solid oxide fuel cell anodes were fabricated by an infiltration method and the effects of the GDC/Ni nanoparticles on the anode polarization resistance and cell performance were investigated in terms of the infiltration time and nickel content. The anodic polarization resistance of the LSFTO anode was significantly enhanced by GDC and/or Ni infiltration and it decreased with increasing infiltration time and Ni content, respectively. It is believed that the observed phenomena are associated with enhancement of the ionic conductivity and catalytic activity in the nanocomposite anodes by the addition of GDC and Ni. Power densities of cells with the LSFTO and LSFTO-GDC/Ni nanocomposite anodes were 150 and $300mW/cm^2$ at $800^{\circ}C$, respectively.

Effect of Zinc Based Anodes on Self-Discharge Behavior for Zinc-Air Batteries (아연-공기 전지용 음극재의 자가방전 억제 효과)

  • Jung, Min Seo;Jo, Yong Nam
    • Korean Journal of Materials Research
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    • v.30 no.12
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    • pp.709-714
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    • 2020
  • For zinc-air batteries, there are several limitations associated with zinc anodes. The self-discharge behavior of zinc-air batteries is a critical issue that is induced by corrosion reaction and hydrogen evolution reaction (HER) of zinc anodes. Aluminum and indium are effective additives for controlling the hydrogen evolution reaction as well as the corrosion reaction. To enhance the electrochemical performances of zinc-air batteries, mechanically alloyed Zn-Al and Zn-In materials with different compositions are successfully fabricated at 500rpm and 5h milling time. Investigated materials are characterized by X-ray diffractometer (XRD), field emission scanning electron microscope (FE-SEM), and energy dispersive spectrometer (EDS). Alloys are investigated for the application as novel anodes in zinc-air batteries. Especially, the material with 3 wt% of indium (ZI3) delivers 445.37 mAh/g and 408.52 mAh/g of specific discharge capacity with 1 h and 6 h storage, respectively. Also, it shows 91.72 % capacity retention and has the lowest value of corrosion current density among attempted materials.

Recent Progress on Polymeric Binders for Silicon Anodes in Lithium-Ion Batteries

  • Choi, Nam-Soon;Ha, Se-Young;Lee, Yongwon;Jang, Jun Yeong;Jeong, Myung-Hwan;Shin, Woo Cheol;Ue, Makoto
    • Journal of Electrochemical Science and Technology
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    • v.6 no.2
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    • pp.35-49
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    • 2015
  • Advanced polymeric binders with unique functions such as improvements in the electronic conduction network, mechanical adhesion, and mechanical durability during cycling have recently gained an increasing amount of attention as a promising means of creating high-performance silicon (Si) anodes in lithium-ion batteries with high energy density levels. In this review, we describe the key challenges of Si anodes, particularly highlighting the recent progress in the area of polymeric binders for Si anodes in cells.

Preparation and Characterization of Insoluble Anodes for Electrodeposition of Ni-W Alloys in Ammoniacal Citrate Bath (Ni-W 합금도금용 불용성 양극의 제조 및 특성 연구)

  • 장도연;강성군
    • Journal of the Korean institute of surface engineering
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    • v.32 no.6
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    • pp.686-694
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    • 1999
  • Insoluble anodes of the Ta/Ir mixed metal oxide for electrodeposition of Ni-W alloy in ammoniacal citrate bath were prepared by thermal decomposition method. Ti plate was etched in boiling oxalic acid solution and coated with ethanol solution of $TaCl_{5}$ and $IrCl_4$ mixed in a fixed ratio, followed by drying and treating at various temperatures. The coating layer of these insoluble anode was characterized by SEM, EDX, XRD and DSC. The decomposition rate of citric acid in plating bath was determined by measuring the $CO_2$ gas evolved at the anodes with Gas Chromatography. Evolution of $CO_2$ gas from Ta/Ir oxide anodes decreased about 5% compared with that of Pt. The $CO_2$ gas evolution was increased with the amount of Ir-oxide in the coatings. The coatings which have more than 40% ratio of Ta content and heat-treated at the temperature higher than $400^{\circ}C$ showed better efficiency

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Effective Approaches to Preventing Dendrite Growth in Lithium Metal Anodes: A Review

  • Jaeyun Ha;Jinhee Lee;Yong-Tae Kim;Jinsub Choi
    • Applied Chemistry for Engineering
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    • v.34 no.4
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    • pp.365-382
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    • 2023
  • A lithium metal anode with high energy density has the potential to revolutionize the field of energy storage systems (ESS) and electric vehicles (EVs) that utilize rechargeable lithium-based batteries. However, the formation of lithium dendrites during cycling reduces the performance of the battery while posing a significant safety risk. In this review, we discuss various strategies for achieving dendrite-free lithium metal anodes, including electrode surface modification, the use of electrolyte additives, and the implementation of protective layers. We analyze the advantages and limitations of each strategy, and provide a critical evaluation of the current state of the art. We also highlight the challenges and opportunities for further research and development in this field. This review aims to provide a comprehensive overview of the different approaches to achieving dendrite-free lithium metal anodes, and to guide future research toward the development of safer and more efficient lithium metal anodes.

Performance of modified graphite as anode material for lithium-ion secondary battery

  • Zheng, Hua;Kim, Myung-Soo
    • Carbon letters
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    • v.12 no.4
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    • pp.243-248
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    • 2011
  • Two different types of graphite, such as flake graphite (FG) and spherical graphite (SG), were used as anode materials for a lithium-ion secondary battery in order to investigate their electrochemical performance. The FG particles were prepared by pulverizing natural graphite with a planetary mill. The SG particles were treated by immersing them in acid solutions or mixing them with various carbon additives. With a longer milling time, the particle size of the FG decreased. Since smaller particles allow more exposure of the edge planes toward the electrolyte, it could be possible for the FG anodes with longer milling time to deliver high reversible capacity; however, their initial efficiency was found to have decreased. The initial efficiency of SG anodes with acid treatments was about 90%, showing an over 20% higher value than that of FG anodes. With acid treatment, the discharge rate capability and the initial efficiency improved slightly. The electrochemical properties of the SG anodes improved slightly with carbon additives such as acetylene black (AB), Super P, Ketjen black, and carbon nanotubes. Furthermore, the cyclability was much improved due to the effect of the conductive bridge made by carbon additives such as AB and Super P.