• Transactions of the Korean hydrogen and new energy society
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• v.10 no.2
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• pp.141-149
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• 1999

Recently the Ni/MH secondary battery has been studied extensively to achieve higher energy density, longer cycle life and faster charging-discharging rate etc. In this work, the electrode properties of $(LM)Ni_{4.49}Co_{0.1}Mn_{0.205}Al_{0.205}$ alloy and $Ti_{0.6}Zr_{0.4}V_{0.6}Ni_{1.4}$ alloy with addition of Pd were investigated. These alloys did not show any change in XRD pattern by Pd addition. As Pd was added as alloy element, the activation behavior was not affected significantly in both $AB_2$ type and $AB_5$ type electrodes and, On charging and discharging in high current density, Discharge capacity with increasing of Pd content was more decreased. But cycle life was showed increasing. Especially the electrode of $Ti_{0.6}Zr_{0.4}V_{0.6}Ni_{1.4}+0.5wt%$ Pd alloy was not almost decreased discharge capacity for 400cycles.

• 한국전자현미경학회:학술대회논문집
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• 1995.12a
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• pp.27-28
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• 1995

• 한국전자현미경학회:학술대회논문집
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• 1997.05a
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• pp.58-61
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• 1997

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.169-170
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• 2012

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.682-683
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• 2012

• Proceedings of the Materials Research Society of Korea Conference
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• 1998.11a
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• pp.57-57
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• 1998

• Journal of the Korean Electrochemical Society
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• v.18 no.2
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• pp.68-74
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• 2015

To compare the microstructure and electrochemical properties between two binary alloys (Cr-Si, Ni-Si), two composition of binary alloys with the same capacity were selected using phase-diagram and prepared by matrix-stabilization method to suppress the volume expansion of Si by inactive-matrix. Master alloys were made by Arc-melting followed by fine structured ribbon sample preparation by Rapid Solidification Process (RSP, Melt-spinning method) under the same conditions. Also powder samples were produced by wet grinding for X-Ray Diffraction (XRD) and electrochemical measurements. As predicted from the phase diagram, only active-Si and inactive-matrix ($CrSi_2$, $NiSi_2$) were detected. The results of Scanning Electron Microscope (SEM) and Transmission Electron Microscopy - Energy Dispersive X-ray Spectroscopy (TEM-EDS) show that Cr-Si alloy has finer microstructure than Ni-Si alloy, which was also predictable through phase diagram. The electrochemical properties related to microstructure were evaluated by coin type full- and half-cells. Separately, self-designed test-cells were used to measure the volume expansion of Si during reaction. Volume expansion of Cr-Si alloy electrode with finer microstructure was suppressed significantly and improved in cycle capability, in comparison Ni-Si alloy with coarse microstructure. From these, we could infer the correlation of microstructure, volume expansion and electrochemical degradation and these properties might be predicted by phase diagram.

• Applied Chemistry for Engineering
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• v.19 no.2
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• pp.185-190
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• 2008

In order to increase the surface area of electrodes for electrosorption, porous carbon electrodes were fabricated by a wet phase inversion method. A carbon slurry consisting of a mixture of activated carbon powder (ACP), polyvinylidene fluoride (PVdF), and N-methyl-2-pyrrolidone (NMP) as a solvent was cast directly on a graphite sheet. The cast film was then immersed in pure water for phase inversion. The physical and electrochemical properties of the electrodes were investigated using scanning electron microscopy (SEM), porosimetry, and cyclic voltammetry. The SEM images verified that the pores of various sizes were formed uniformly on the electrode surface. The average pore sizes determined for the electrodes fabricated with various NMP contents ranged from 64.2 to 82.4 nm and the size increased as the NMP content increased. All of the voltammograms showed a typical behavior of charging and discharging characteristic at the electric double layer. The electrical capacitance ranged from 3.88 to $5.87F/cm^2$ depending on the NMP contents, and the electrical capacitance increased as the solvent content decreased. The experimental results showed that the solvent content is an important variable controlling pore size and ultimately the capacitance of the electrode.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1740-1742
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• 2004

산소 과전압이 낮은 $MnO_2$를 촉매로 사용하여 반도체 산화물계의 산소선택성 전극을 제조하고 산화물 코팅층의 미세구조와 전기화학적 특성을 분석하였다. Ti 기판에 열분해 법을 이용하여 $MnO_2$ 피막을 형성하였고, 또한 binder를 이용한 코팅 방법을 이용하여 Ti, Fb 기판에 $MnO_2$ 피막층을 형성하였다. 450$^{\circ}C$에서 1시간 열분해하여 약 1 ${\mu}m$의 $MnO_2$ 피막층을 형성 시켰으나 Ti 기판과의 접착력이 약하여 피막자체에 대한 전기화학적 특성은 관찰할 수 없었다. PVDF : $MnO_2$의 함량비가 1:1에서 1:6 까지는 DMF의 함량에 무관하게 전극 특성이 나타나지 않았지만 20:1 이상의 조성에서는 균일한 C-V 특성을 나타냈고, 산소 발생 과전압도 약 1.4V 정도로 감소되었다. 그러나 Ti 기판의 경우 열분해법을 이용하여 제조된 전극과 같이 낮은 기판과의 접착력 때문에 $MnO_2$ 피막층의 촉매효과가 현저하게 감소하였다.

• Analytical Science and Technology
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• v.11 no.4
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• pp.235-242
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• 1998

Membrane electrode based on chitin(po1y-[$1{\rightarrow}4$]-${\beta}$-N-acetyl-D-glucosamine) was prepared by mixing uniformly grounded of chitin (100 mesh) with PVC and DOS. We investigated the potential response of chitin membrane electrode to metal ions. It was observed that the response slopes for $Cd^{2+}$(34.9 mV/decade) and $Cu^{2+}$(34.0 mV/decade) were larger than those for other ions in pH 4 acetate buffer. The potentiometric response of chitin electrode to varying pH was nearly constant in the pH range of 2~12.