• Title/Summary/Keyword: electrode charging

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Study on the Electrochemical Characteristics of a EGaIn Liquid Metal Electrode for Supercapacitor Applications (수퍼커패시터 응용을 위한 EGaIn 액체 금속 전극의 전기화학 특성 연구)

  • SO, JU-HEE;KOO, HYUNG-JUN
    • Transactions of the Korean hydrogen and new energy society
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    • v.27 no.2
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    • pp.176-181
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    • 2016
  • Recent years, supercapacitors have been attracting a growing attention as an efficient energy storage, due to their long-lifetime, device reliability, simple device structure and operation mechanism and, most importantly, high power density. Along with the increasing interest in flexible/stretchable electronics, the supercapacitors with compatible mechanical properties have been also required. A eutectic gallium-indium (EGaIn) liquid metal could be a strong candidate as a soft electrode material of the supercapacitors because of its insulating surface oxide layer for electric double layer formation. Here, we report the electrochemical study on the charging/reaction process at the interface of EGaIn liquid metal and electrolyte. Numerical fitting of the charging current curves provides the capacitance of EGaIn/insulating layer/electrolyte (${\sim}38F/m^2$). This value is two orders of magnitude higher than a capacitance of a general metal electrode/electrolyte interface.

Multilayer Piezoelectric Energy Harvester and Charging Property in Capacitor (다층형 압전세라믹 발전기 제작 및 capacitor 충전 특성)

  • Kim, Hyung-Chan;Song, Hyun-Cheol;Lee, Ju-Young;Jeong, Dae-Yong;Kim, Hyun-Jae;Yoon, Seok-Jin;Ju, Byeong-Kwon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.301-302
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    • 2007
  • Energy harvesting from the vibration through the piezoelectric effect has been studied for powering the wireless sensor node. For the driving wireless sensor node, the generated energy is required to store the capacitor or battery. For the rapid charging, higher voltage than battery's capacity voltage and a large current are necessitated. However, the piezoelectric energy harvester is generally featured as a high voltage and low current generator. As it is known that the generated current in the piezoelectric energy harvester is related to an area of electrode of piezoelectric ceramics, we fabricated the multilayer ceramics to increase effective area for the faster charging. The energy harvesting properties and charging characteristics of multilyaer ceramics were investigated and discussed.

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INVESTIGATION OF "STEPPED" DISCHARGE CURVES IN SINTERED TYPE NICKEL-CADMIUM CELL

  • SASAKI, Y.;YAMASHITA, T.
    • Journal of the Korean institute of surface engineering
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    • v.32 no.3
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    • pp.360-362
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    • 1999
  • Formation of the nickel-cadmium alloy in the negative electrode of nickel-cadmium cell subjected to continuous charging at elevated temperatures ($40~45^{\circ}C$) is shown to be one of the causes of the 'stepped' discharge curves. The alloy has been characterized by electrode potential measurement and X-ray diffraction method. The potential lowering during discharge is related to discharge of the alloy. X -ray diffraction suggests that the nickel-cadmium alloy can be formed during charge in negative electrode by interaction of the two metals. Addition of Ni $(OH)_2$ into $Cd{\;}(OH)_2$ active material is found to form the alloy more readily than sintered negative electrode alone.ode alone.

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Improved Performance of Lithium-Ion Batteries using a Multilayer Cathode of LiFePO4 and LiNi0.8Co0.1Mn0.1O2

  • Hyunchul Kang;Youngjin Kim;Taeho Yoon;Junyoung Mun
    • Journal of Electrochemical Science and Technology
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    • v.14 no.4
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    • pp.320-325
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    • 2023
  • In Li-ion batteries, a thick electrode is advantageous for lowering the inactive current collector portion and obtaining a high energy density. One of the critical failure mechanisms of thick electrodes is inhomogeneous lithiation and delithiation owing to the axial location of the electrode. In this study, it was confirmed that the top layer of the composite electrode contributes more to the charging step owing to the high ionic transport from the electrolyte. A high-loading multilayered electrode containing LiFePO4 (LFP) and LiNi0.8Co0.1Mn0.1O2 (NCM811) was developed to overcome the inhomogeneous electrochemical reactions in the electrode. The electrode laminated with LFP on the top and NCM811 on the bottom showed superior cyclability compared to the electrode having the reverse stacking order or thoroughly mixed. This improvement is attributed to the structural and interfacial stability of LFP on top of the thick electrode in an electrochemically harsh environment.

Plasma damage of MIS(TaN/$HfO_2$/Si) capacitor using antenna structure (Antenna structure를 이용한 MIS(TaN/$HfO_2$/Si) capacitor의 plasma damage 연구)

  • Yang, Seung-Kook;Lee, Seung-Yong;Yu, Han-Suk;Kim, Han-Hyung;Song, Ho-Young;Lee, Jong-Geun;Park, Se-Geun
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.551-552
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    • 2006
  • Plasma-induced charging damage was been measured during TaN gate electrode of MISFET(TaN/$HfO_2$/Si) or interconnection metal etching step using large antenna structures. The results of these experiments were obtained that $HfO_2$ gate dielectric layer was affected about plasma charging effects and damage increased with F-N tunneling. Therefore, the etching conditions should be optimized to avoid the defects caused by plasma charging.

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Enhancement of Quick-Charge Performance by Fluoroethylene Carbonate additive from the Mitigation of Electrode Fatigue During Normal C-rate Cycling

  • Tae Hyeon Kim;Sang Hyeong Kim;Sung Su Park;Min Su Kang;Sung Soo Kim;Hyun-seung Kim;Goojin Jeong
    • Journal of Electrochemical Science and Technology
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    • v.14 no.4
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    • pp.369-376
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    • 2023
  • The quick-charging performance of SiO electrodes is evaluated with a focus on solid electrolyte interphase (SEI)-reinforcing effects. The study reveals that the incorporation of fluoroethylene carbonate (FEC) into the SiO electrode significantly reduced the electrode fatigue, which is from the the viscoelastic properties of the FEC-derived SEI film. The impact of FEC is attributed to its ability to minimize the mechanical failure of the electrode caused by additional electrolyte decomposition. This beneficial outcome arises from volumetric stain-tolerant characteristics of the FEC-derived SEI film, which limited exposure of the bare SiO surface during 0.5 C-rate cycling. Notably, FEC greatly improves Li deposition during quick-charge cycles following aging at 0.5 C-rate cycling due to its ability to maintain a strong electrical connection between active materials and the current collector, even after extended cycling. Given these findings, we assert that mitigating SEI layer deterioration, which compromises the electrode structure, is vital. Hence, enhancing the interfacial attributes of the SiO electrode becomes crucial for maintaining kinetic efficiency of battery system.

A Study on an Ion Wind Created by a Wire Electrode and Parallel Plates Assembly (와이어 전극과 평행판에서 발생되는 이온풍 특성 연구)

  • 안영철;황필재;이재근
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.16 no.4
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    • pp.318-323
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    • 2004
  • When a strong electric field is applied between a sharply curved electrode and a blunt surface, the corona may result in a gas movement in the electrode gap which is directed toward the blunt surface. That is called the corona wind. It enhances heat and mass transfer between the surface and the surrounding gas. Moreover such enhancement causes no noise or vibration, which can be applied in complex, isolated geometries, and allows simple control of surface temperatures. This paper examines the relationship between the corona wind and the relative humidity. The facility consists of high voltage power supply thin tungsten wire, plate electrode, multimeter, microammeter and flow meter. Gas velocity is a linear function of voltage, relative humidity and is proportional to the square root of the current. The maximum velocities for the positive and negative corona discharge are 1.9 m/s (2.74 CMM/m), 1.5 m/s(2.15 CMM/m), respectively.