• Corrosion Science and Technology
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• 제2권4호
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• pp.194-196
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• 2003

In this paper, a newest kind of anti-atmospheric corrosion method is introduced. This method does not adopt organic coating, plastic layer or metal plating, instead it adopts a kind of aqueous emulsion containing numerous tine solid compounds that are absorbed onto the component surface, which play the role of anti-electrochemical corrosion.

• Journal of Electrochemical Science and Technology
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• 제12권4호
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• pp.387-397
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• 2021

Deep eutectic solvents have been established as feasible metal electroplating solvent alternatives over traditional toxic aqueous plating baths. However, water, either added intentionally or unintentionally, can significantly influence the solvent's physical properties and performance, thereby hindering its industry application. In this study, the hygroscopicity, or the ability to absorb moisture from the environment, of synthesized ethaline (1:2 choline chloride:ethylene glycol) was investigated. The kinematic viscosity, electrical conductivity, electrochemical window, and water content of ethaline were monitored over a 2-week period. Karl Fischer titration tests showed that ethaline exposed to the atmosphere displayed significant hygroscopicity compared to its unexposed counterpart. ¹H NMR spectroscopy revealed that water vapor was readily absorbed at the surface due to the hydrophilic groups present in the ethaline molecule. Water uptake resulted in the decrease in viscosity, increase in electrical conductivity and narrowing of the electrochemical window of ethaline. Solution heating at 100℃ removed the absorbed moisture and allowed the recovery of the solvent's initial properties.

• Journal of Electrochemical Science and Technology
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• 제11권1호
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• pp.92-98
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• 2020

SnO₂-based high-capacity anode materials are attractive candidate for the next-generation high-performance lithium-ion batteries since the theoretical capacity of SnO₂ can be ideally extended from 781 to 1494 mAh g^-1. Here 3D etched Cu foam is applied as a current collector for electron path and simultaneously a substrate for the SnO₂ coating, for developing an integrated electrode structure. We fabricate the 3D etched Cu foam through an auto-catalytic electroless plating method, and then coat the SnO₂ onto the self-supporting substrate through a simple sol-gel method. The catalytic dissolution of Cu metal makes secondary pores of both several micrometers and several tens of micrometers at the surface of Cu foam strut, besides main channel-like interconnected pores. Especially, the additional surface pores on etched Cu foam are intended for penetrating the individual strut of Cu foam, and thereby increasing the surface area for SnO₂ coating by using even the internal of Cu foam. The increased areal capacity with high structural integrity upon cycling is demonstrated in the SnO₂-coated 3D etched Cu foam. This study not only prepares the etched Cu foam using the spontaneous chemical reactions but also demonstrates the potential for electroless plating method about surface modification on various metal substrates.

• 한국표면공학회지
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• 제49권6호
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• pp.530-538
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• 2016

There is a close relationship between the performance and the heat generation of the electronic device. Heat generation causes a significant degradation of the durability and/or efficiency of the device. It is necessary to have an effective method to release the generated heat. Based on demands of the printed circuit board (PCB) manufacturing, it is necessary to develop a robust and reliable plating technique for substrates with high thermal conductivity, such as alumina ($Al_2O_3$), aluminium nitride (AlN), and silicon nitride ($Si_3N_4$). In this study, the plating of metal layers on an insulating silicon nitride ($Si_3N_4$) ceramic substrate was developed. We formed a Pd-$TiO_2$ adhesion layer and used APTES(3-Aminopropyltriethoxysilane) to form OH groups on the surface and adhere the metal layer on the insulating $Si_3N_4$ substrate. We used an electroless Ni plating without sensitization/activation process, as Pd particles were nucleated on the $TiO_2$ layer. The electrical resistivity of Ni and Cu layers is $7.27{\times}10^{-5}$ and $1.32{\times}10^{-6}ohm-cm$ by 4 point prober, respectively. The adhesion strength is 2.506 N by scratch test.

• 한국표면공학회지
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• 제51권4호
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• pp.243-248
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• 2018

All solid state thin film batteries with two types of cell structure, Pt / $LiCoO_2$ / LiPON / Cu and Pt / $LiCoO_2$ / LiPON / $LiCoO_2$ / Cu, are prepared and their electrochemical performances are investigated to evaluate the effect of $LiCoO_2$ interlayer at the interface of LiPON / Cu. The crystallinity of the deposited $LiCoO_2$ thin films is confirmed by XRD and Raman analysis. The crystalline $LiCoO_2$ cathode thin film is obtained and $LiCoO_2$ as the interlayer appears to be amorphous. The surface morphology of Cu current collector after cycling of the batteries is observed by AFM. The presence of a 10 nm-thick layer of $LiCoO_2$ at the interface of LiPON / Cu enhances the interfacial adhesion and reduces the interfacial resistance. As a result, Li plating / stripping at the interface of LiPON / Cu during charge/discharge reaction takes place more uniformly on Cu current collector, while without the interlayer of $LiCoO_2$ at the interface of LiPON / Cu, the Li plating / stripping is localized on current collector. The thin film batteries with the interlayer of $LiCoO_2$ at the interface of LiPON / Cu exhibits enhanced initial coulombic efficiency, reversible capacity and cycling stability. The thickness of the anode current collector Cu also appears to be crucial for electrochemical performances of all solid state thin film batteries.

• 전기화학회지
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• 제25권2호
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• pp.81-87
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• 2022

본 연구에서는, 알킬아민이 구리전해도금에 미치는 영향을 cyclic voltammetry를 이용해 분석해보았다. 수용액상 용해도를 갖는 알킬아민을 도금액에 첨가할 경우, Cu²⁺의 환원반응이 억제되는 것을 확인할 수 있었다. 다양한 알킬아민 중 1,12-diaminododecane에 대해 다양한 농도 및 도금액 조건에서 억제 효과를 관찰하였다. 1,12-diaminododecane은 산성 도금액상에서 protonation 되어, Cu²⁺의 착화제로써 작용하지 않았으며, 따라서 1,12-diaminododecane의 억제 효과는 Cu 표면상 흡착에 의한 것임을 확인할 수 있었다. 1,12-diaminododecane는 (i) protonation에 의한 양이온화와 그에 따른 Cu 표면상 기흡착한 음이온과의 정전기적 인력에 의한 흡착과 (ii) amine에 의한 Cu 표면상 직접 흡착의 두가지 특성을 모두 가지고 있었다. 흡착한 1,12-diaminododecane은 도금 반응을 억제할 뿐만 아니라, 구리도금막 형성시 3차원적 성장과 표면 미세화를 야기하였다.

• Journal of Electrochemical Science and Technology
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• 제14권1호
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• pp.85-95
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• 2023

In recent years, solid-state Li metal batteries (SSLBs) have attracted significant attention as the next-generation batteries with high energy and power densities. However, uncontrolled dendrite growth and the resulting pulverization of Li during repeated plating/stripping processes must be addressed for practical applications. Herein, we report a plastic-crystal-based polymer/ceramic composite solid electrolyte (PCCE) to resolve these issues. To fabricate the one-side ceramic-incorporated PCCE (CI-PCCE) film, a mixed precursor solution comprising plastic-crystal-based polymer (succinonitrile, SN) with garnet-structured ceramic (Li₇La₃Zr₂O₁₂, LLZO) particles was infused into a thin cellulose membrane, which was used as a mechanical framework, and subsequently solidified by using UV-irradiation. The CI-PCCE exhibited good flexibility and a high room-temperature ionic conductivity of over 10^-3 S cm^-1. The Li symmetric cell assembled with CI-PCCE provided enhanced durability against Li dendrite penetration through the solid electrolyte (SE) layer than those with LLZO-free PCCEs and exhibited long-term cycling stability (over 200 h) for Li plating/stripping. The enhanced Li⁺ transference number and lower interfacial resistance of CI-PCCE indicate that the ceramic-polymer composite layer in contact with the Li anode enabled the uniform distribution of Li⁺ flux at the interface between the Li metal and CI-PCCE, thereby promoting uniform Li plating/stripping. Consequently, the Li//LiFePO₄ (LFP) full cell constructed with CI-PCCE demonstrated superior rate capability (~120 mAh g^-1 at 2 C) and stable cycle performance (80% after 100 cycles) than those with ceramic-free PCCE.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.602-606
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• 2003

Silicon has been developed as an alternate anode material for lithium secondary batteries. A simple approach to improve the electrical contact of silicon powder has described. Carbon-coated and silver-coated silicon have been prepared by chemical vapor deposition and electroless plating respectively. Assembled cells, which consisted of surface modified silicon, lithium foil and $Li^+$ contained organic electrolyte, have been studied using electrochemical methods. Carbon-coated silicon was improved in the electrochemical performance such as reversibility and resistance compared to surface-unmodified silicon.

• 한국수소및신에너지학회논문집
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• 제4권2호
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• pp.29-40
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• 1993

Intensive studies on the electrochemical characteristics of TiFe type alloy electrodes have been carried out to clarify the mechanism of electrochemical hydrogen absorption and desorption. It was found that electrochemical activation of the TiFe type alloys is difficult and that charge efficiencies are very low even after a decade of activation cycles. However, by the pretreatment of the powders such as gas activation and/or Ni chemical plating, charge efficiencies fairly increased, especially for the $TiFe_{0.8}Ni_{0.2}$ alloy. It was considered that difficulties to activation and lower charge efficies of the alloys are due to the presence of the passivation films, which prohibit inward diffusion of hydrogen and promote the combination of adsorbed hydrogen atom to gas bubbles during the electrochemical charge. In addition, lower diffusivity of hydrogen in the alloys may be played an important role lowering the charge efficiencies.

• Bulletin of the Korean Chemical Society
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• 제33권5호
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• pp.1603-1607
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• 2012

The effects of plating process on the surface coverage of the accelerator were investigated in terms of Cu superfilling for device metallization. When a substrate having 500 nm-wide trench patterns on it was immersed in an electrolyte containing poly (ethylene glycol) (PEG)-chloride ion ($Cl^-$)-bis(3-sulfopropyl) disulfide (SPS) additives without applying deposition potential for such a time of about 100s, voids were generated inside of the electrodeposit. In time-evolved electrochemical analyses, it was observed that the process (immersion without applying potential) in the electrolyte led to the build-up of high initial coverage of SPS-Cl on the surface, resulting in the fast saturation of the coverage. Repeated experiments suggested that the fast saturation of SPS-Cl failed in superfilling while a gradual increase in the SPS-Cl coverage through competition with initially adsorbed PEG-Cl enabled it. Consequently, superfilling was achievable only in the case of applying the plating potential as soon as the substrate is dipped in an electrolyte to prevent rapid accumulation of SPS-Cl on the surface.