• KIPE Magazine
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• v.11 no.3
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• pp.15-19
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• 2006

• Transactions of the Korean hydrogen and new energy society
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• v.17 no.4
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• pp.418-424
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• 2006

In order to improve the activation properties of the $AB_2$ type hydrogen storage alloys for Ni-MH battery, the alloy surface was modified by employing high energy ball milling. The $Zr_{0.54}Ti_{0.45}V_{0.54}Ni_{0.87}Cr_{0.15}Co_{0.21}Mn_{0.24}$ alloy powder was ball milled for various period by using the high energy ball mill. As the ball milling time increased, activation of the $AB_2$ type composite powder electrodes were enhanced regardless of additives. When the ball milling time was small discharge capacities of the $AB_2$ type composite powder electrodes increased with the milling time. On the other hand for large milling time it decreased with increasing milling time. The maximum discharge capacity was obtained by ball milling for 3-4 min.

• Transactions of the Korean hydrogen and new energy society
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• v.8 no.2
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• pp.51-56
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• 1997

The Zr-based Laves phase, $ZrV_2$ hydrogen storage alloy is not suited for the electrode of Ni-MH battery, because the binding strength of that with hydrogen is too strong although the storage capacity is high. For an application to electrode a part of V in alloys is substituted with Ni to make weaken the binding strength. The electrochemical and thermodynamic properties of Zr-V-Ni system alloys are investigated from the equilibrium potential and studied the possibility for the application to the rechargeable battery electrode.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.66-69
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• 2000

전기자동차에서 주 에너지원은 축전지이다. 현재전기자동차용 축전지는 에너지 밀도 및 파워 밀도가 커지고 있지만 기존의 자동차에 비해서 주행거리가 짧다. 그래서 전지관리장치(Battery management System : BMS) 개발목적은 효율적으로 배터리를 관리하여 전기자동차의 전력시스템을 최적으로 운전하는 데 있다. 주행 중 즉 모터링시 축전시의 상태에 따라 인버터의 운전을 최적으로 하기 위한 제어방식을 도입하고 충전시에도 축전시의 충전상태에 따른 충전모드를 선택하여 제어하는 방식을 도입하고자 한다. 전기자동차 전력시스템의 최적운전을 실현할 수 있고 이를 통해 주행거리를 증대시킬수 있는 전기자동차 용 Ni-MH 전지 제어 알고리즘을 이용하여 개발한 BMS에 대해 소개한다.

• Transactions of the Korean hydrogen and new energy society
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• v.18 no.4
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• pp.365-373
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• 2007

We optimized the compositions of electrolyte and additives for anode in Ni-MH battery to improve the electrode characteristics at ambient and low temperatures using response surface method(RSM). Among various additives for anode, PTFE exhibited the greatest influence on the discharge capacity of the anode. Through response optimization process, we found the optimum composition of the additives to exhibit the greatest discharge capacity. When the amount of additives was too small, the anode was degraded with time due to the low binding strength among alloy powders and the resultant separation of powders from the current collector. In contrast, the addition of large amount of the additives increased in the resistance of the electrode. In addition, the discharge capacity of the anode at $-18^{\circ}C$ increased with decreasing the concentration of KOH, NaOH and LiOH in design range of electrolyte. The resistance and viscosity of electrolyte appear to affect the discharge capacity of the anode at low temperature.

• Applied Chemistry for Engineering
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• v.8 no.6
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• pp.1034-1040
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• 1997

Temperature distribution of battery module consists of 11 batteries of 90Ah rate is analyzed using commercial software NISA II. Equivalent thermal resistance network is used to reduce the number of element in calculating heat transfer through a medium composed of several different thermal conductivity layers. Orthotropic model is used to put different thermal conductivity values according to Cartesian coordinate. Aluminum cooling fins are inserted in the middle of batteries to reduce battery module temperature. The cooling fin at the end of the module does not necessary in reducing maximum temperature. Combined effect of front and side cooling fin is analyzed to reduce the temperature difference among batteries. The maximum temperature difference among batteries is reduced within $3^{\circ}C$ when 4 aluminum cooling tin of 1mm thickness is inserted in battery module.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.2
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• pp.45-49
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• 2006

Electrochemical hydrogenation/dehydrogenation properties were studied for a single particle of a Mm-based(Mm : minh metal) hydrogen storage alloy($MmNi_{3.55}Co_{0.75}Mn_{0.4}Al_{0.3}$) for fuel cell and Ni-MH batteries. A carbon fiber microelectrode was manipulated to make electrical contact with an alloy particle, and the potential-step experiment was carried out to determine the apparent chemical diffusion coefficient of hydrogen atom($D_{app}$) in the alloy. Since the alloy particle we used here was a dense, conductive sphere, the spherical diffusion model was employed for data analysis. $D_{app}$ was found to vary the order between $10^{-9}\;and\;10^{-10}[cm^2/s]$ over the course of hydrogenation and dehydrogenation process. Compared with the conventional composite film electrodes, the single particle measurements using the microelectrode gave more detailed, true information about the hydrogen storage alloy.

• Journal of the Korean institute of surface engineering
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• v.28 no.2
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• pp.83-91
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• 1995

A new method for preparation of thin nickel foam for Ni-MH battery was investigated. In this method, fine graphite powders of $1\mu\textrm{m}$～$2\mu\textrm{m}$ diameter were pasted into pores of thin polyurethane foam film in order to supply electric conducting seeds for nickel deposition by electroless plating reaction. After electroless plating, remaining polyurethane foam was removed chemically by organic solvent treatment and graphite particles also removed by ultrasonic cleaning. Porosity of formed nickel foam was about 85% During electroplating, porosity of the nickel foam decreased less than 5% up to $30\mu\textrm{m}$ coating thickness. And then it was electroplated and heat-treated to improve mechanical strength and ductility. Finally, thin nickel foam for Ni electrode of Ni-MH battery with 80% porosity and $350\mu\textrm{m}$～X$400\mu\textrm{m}$ thickness was obtained.

• Electrical & Electronic Materials
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• v.12 no.1
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• pp.28-33
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• 1999

• Resources Recycling
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• v.26 no.2
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• pp.3-10
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• 2017

Rare earth elements with high purity are demanded for the manufacture of advanced materials. Light rare earth elements are contained in domestic monazite and Ni-MH batteries. In this paper, solvent extraction to separate the light rare earth elements from hydrochloric acid leaching solutions of these resources was discussed. A mixture of cationic and tertiary amine shows synergistic effect on the extraction of LREEs and the extent of pH decrease during extraction is reduced. The effect of solution pH on the extraction and synergism was reviewed. Acquisition of the operation data with mixer-settler on the separation of LREEs by this mixture is necessary to develop a process.