• Title/Summary/Keyword: Ni-MH battery

Search Result 55, Processing Time 0.203 seconds

Development of Preparation Technique of Sintered Ni Electrode (소결식 니켈극 제조기술 개발)

  • Kim, Chan-Jung;Kim, Dai-Ryong
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.10 no.3
    • /
    • pp.159-170
    • /
    • 1999
  • Recently Ni/MH secondary battery have been studied very extensively because of containing no pollutants as well as superior performance. However comparing to widely studying high capacity of hydrogen storage alloys electrode, the capacity of Ni electrode is inferior. Using for high capacity Ni/MH battery as a anodic materials, the study about high capacity Ni electrode is necessary. To making high capacity Ni electrode, active materials were impregnated in various polarization impregnation conditions. Plaque, milling for 6hr and sintered at $800^{\circ}C$, indicated porosity over 80%, and porosity were increased with proper condition electrochemical etching treatment. Proper impregnation condition was 40~80mA/cm, polarizing time was 5~10min.

  • PDF

Electrochemical Properties of Laves Phase Zr-V System Hydrogen Absorbing Alloys (Zr-V계 Laves상 수소저장합금의 전기화학적 성질)

  • Park, Chan-kyo;Cho, Tae-hwan
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.8 no.2
    • /
    • pp.51-56
    • /
    • 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.

  • PDF

Electrochemical properties of $AB_5$-type Hydrogen alloys upon addition of Zr, Ti and V ($AB_5$계 수소저장합금의 Zr, Ti 및 V 첨가에 따른 전기화학적특성)

  • Kim, D.H.;Cho, S.W.;Jung, S.R.;Park, C.N.;Choi, J.
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.17 no.1
    • /
    • pp.31-38
    • /
    • 2006
  • There are two types of metal hydride electrodes as a negative electrode in a Ni-MH battery, $AB_2$ Zr-based Laves phases and $AB_5$ LM(La-rich mischmetal)-based alloys. The $AB_5$ alloy electrodes have characteristic properties such as a large discharge capacity per volume, easiness in activation, long cycle life and a low cost of alloy. However they have a relatively small discharge capacity per weight. The $AB_2$alloy electrodes have a much higher discharge capacity per weight than $AB_5$ alloy electrodes, however they have some disadvantages of poor activation behavior and cycle life. Therefore, in order to improve the discharge capacity of the $AB_5$ alloy electrode the Zr, Ti and V which are the alloying elements of the $AB_2$ alloys were added to the $LaNi_{3.6}Ai_{0.4}Co_{0.7}Mn_{0.3}$ alloy which was chosen as a $AB_5$ alloy with a high capacity. The addition of Zr, Ti and V to $LaNi_{3.6}Ai_{0.4}Co_{0.7}Mn_{0.3}$ alloy improved the activation to be completed in two cycles. The discharge capacities of Zr 0.02, Ti 0.02 and V 0.1 alloys in $LaNi_{3.6}Ai_{0.4}Co_{0.7}Mn_{0.3}M_y$ (M = Zr, Ti, V) were respectively 346, 348 and 366 mAh/g alloy. The alloy electrodes, Zr 0.02, Ti 0.05 and V 0.1 in $LaNi_{3.6}Ai_{0.4}Co_{0.7}Mn_{0.3}M_y$ (M = Zr, Ti, V), have shown good cycle property after 200 cycles. The rate capability of the $LaNi_{3.6}Ai_{0.4}Co_{0.7}Mn_{0.3}M_y$ (M = Zr, Ti, V) alloy electrodes were very good until 0.6 C rate and the alloys, Zr 0.02, Ti 0.05 and V 0.1, have shown the best result as 92 % at 2.4 C rate. The charge retention property of the $LaNi_{3.6}Ai_{0.4}Co_{0.7}Mn_{0.3}M_y$ (M = Zr, Ti, V) alloys was not good and the alloys with M content from 0.02 to 0.05 showed better charge retention properties.

An Improvement in the Properties of MH Electrode of Ni/MH Battery by the Copper Coating (Ni/MH 전지에서 Cu 도금에 의한 음극활물질의 전극 특성 향상)

  • Cho, Jin Hun;Kim, In Jung;Lee, Yun Sung;Nahm, Kee Suk;Kim, Ki Ju;Lee, Hong Ki
    • Applied Chemistry for Engineering
    • /
    • v.8 no.4
    • /
    • pp.568-574
    • /
    • 1997
  • The effect of microencapsulation of maetal hydride (MH) with copper on the electrode performance of a Ni/MH battery has been investigated. The MH electrodes were prepared with a combination of cold press and paste methods. The discharge capacity of the electrode increased with an addition of small amounts if CMC into the electrode, but decreased when heat-treated in an oxygen-free nitrogen flow. The capacity of a Cu-coated $LaNi_5$ electrode was higher than that of LaNi5electrode. The discharge capacity of the electrode prepared with Cu-coated $LaNi_5$ increased with the increase of copper content in the electrode. It is considered that the increase of copper content enhanced the current density on the electrode surface, leading to the increase of the discharge capacity The MH electrode coated by an acidic electroless plating method showed much higher discharge capacity than that using an alkaline electroless plating method. The discharge capacity of the $LaNi_{4.5}Al_{0.5}$ electrode was higher than that of the $LaNi_5$ electrode. Also, the effect of microencapsulation on the deactivation of $LaNi_5$ was studied using an absorption-desorption cycle in CO-containing hydrogen.

  • PDF

Electrochemical Behavior of a Nickel Hydroxide Particle for Ni-MH Battery by Microelectrode (마이크로전극에 의한 니켈수소전지용 수산화니켈 입자의 전기화학적 거동)

  • Kim, Ho-Sung;Oh, Ik-Hyun;Lee, Jong-Ho
    • Journal of the Korean Electrochemical Society
    • /
    • v.10 no.2
    • /
    • pp.145-149
    • /
    • 2007
  • Electrochemical studies were performed for a single particle of nickel hydroxide for the cathode of Ni-MH batteries. A carbon fiber microelectrode was manipulated to make electrical contact with an alloy particle, and electrochemical experiments were performed. As a result of cyclic voltammetry, the oxidation/reduction and oxygen evolution reaction (OER) are clearly separated for a single particle. The total cathodic charge (Qred) is practically constant for the scan rate investigated, indicating that the whole particle has reacted. The total anodic charge(Qox) was larger than that of reduction reaction, and the magnitude of oxygen evolution taking place as a side reaction was enhanced at lower scan rates. As a result of galvanostatic charge and discharge measurement, the discharge capacity of single particle was found to be 250 mAh/g, value being very close to the theoretical capacity (289 mAh/g). The apparent proton diffusion coefficient(Dapp) using potential step method inside the nickel hydroxide was found to range within $3{\sim}4{\times}10^{-9}\;cm^2/s$.

Effect of the compacting additives on the Discharge Characteristics of the Negative Electrode for Ni-MH Battery (니켈-수소저장합금전지 음극의 방전특성에 미치는 성형첨가제의 영향)

  • Jung, Jae-Han;Lee, Han-Ho;Kim, Dong-Myung;Lee, Kee-Young;Lee, Jai-Young
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.6 no.2
    • /
    • pp.65-73
    • /
    • 1995
  • Negative electrode was prepared by mixing $Ti_{0.7}Zr_{0.3}Cr_{0.3}Mn_{0.3}V_{0.6}Ni_{0.8}$ alloy powder with copper or nickel powder and pressing in the air. The cycled electrodes were analyzed with SEM, potentiostat and electrochemical impedance spectroscopy. It was found that the Cu-compacted electrode showed better low temperature dischargeability and higher rate capability than Ni-compacted electrode. From SEM analysis of the cycled electrode compacted with copper powder, it was observed that the surface of MH particles was covered with copper grains and whisker precipitated from electrolyte after dissolution during cell test. It is found that the improved electrode characteristics are attributed to the copper layer on MH particles deposited by dissolution and precipitation(DP) process.

  • PDF

Thermal Management of a Ni/MH Battery Module for Electric Vehicle (전기자동차용 Ni/MH 전지 Module의 열관리기술)

  • Kim, Junbom
    • Applied Chemistry for Engineering
    • /
    • v.8 no.6
    • /
    • pp.1034-1040
    • /
    • 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.

  • PDF

Separation of Light Rare Earth Elements by Solvent Extraction with a Mixture of Cationic and Tertiary Amine (양이온 추출제와 아민의 혼합추출제에 의한 경희토류금속의 분리)

  • Lee, Man-Seung;Son, Seong Ho
    • Resources Recycling
    • /
    • v.26 no.2
    • /
    • pp.3-10
    • /
    • 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.

Production Processes of Porous Metals and Their Applications (다공질 금속의 제조와 응용)

  • Shim, Jae-Dong;Byun, Ji-Young
    • Korean Journal of Materials Research
    • /
    • v.25 no.3
    • /
    • pp.155-164
    • /
    • 2015
  • Porous metals are called as a new material of 21th century because they show not only extremely low density, but also novel physical, thermal, mechanical, electrical, and acoustic properties. Since the late in the 1990's, considerable progress has been made in the production technologies of many kinds of porous metals such as aluminum, titanium, nickel, copper, stainless steel, etc. The commercial applications of porous metals have been increased in the field of light weight structures, sound absorption, mechanical damping, bio-materials, thermal management for heat exchanger and heat sink. Especially, the porous metals are promising in automotive applications for light-weighting body sheets and various structural components due to the good relation between weight and stiffness. This paper reviews the recent progress of production techniques using molten metal bubbling, metal foaming, gas expansion, hollow sphere structure, unidirectional solidification, etc, which have been commercialized or under developing, and finally introduces several case studies on the potential applications of porous metals in the area of heat sink, automotive pannel, cathod for Ni-MH battery, golf putter and medical implant.

Electrode Characteristics of the (Mm)Ni5-Based Hydrogen Storage Alloys ((Mm)Ni5계 수소저장합금의 전극 특성)

  • Han, D.S.;Choi, S.J.;Chang, M.H.;Choi, J.;Park, C.N.
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.6 no.1
    • /
    • pp.35-41
    • /
    • 1995
  • The MmNi-based alloy electrode was studied for use as a negative electrode in Ni-MH battery. Alloys with $MmNi_5-_xM_x$(M=Co,Al,Mn) composition were synthesized, and their electrode charateristics of activation rate, temperature dependence, electrode capacity and cycle life were investigated. With increasing Al content and decreasing Mn content in the alloys, the discharge capacity increased while the cycle life decreased. As x in $MmNi_5-_xM_x$ increased from 1.5 to 2.0, decreasing the Ni content, the discharge capacity, the low temperature property and the rate capability decreased. However its cycle life was improved. Increasing Co content resulted in a prolonged cycle life and decrease of high rate discharge capacity. It can be concluded that the most promising alloy in view of discharge capacity and cycle life is $MmNi_{3.5}Co_{0.7}Al_{0.5}Mn_{0.3}$.

  • PDF