• Transactions of the Korean hydrogen and new energy society
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• v.6 no.1
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• pp.35-41
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• 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 $MmNi_{3.5}Co_{0.7}Al_{0.5}Mn_{0.3}$.

• Applied Chemistry for Engineering
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• v.8 no.4
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• pp.568-574
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• 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.

• Bulletin of the Korean Chemical Society
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• v.30 no.3
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• pp.657-660
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• 2009

The surface of $Li[Ni_{0.8}Co_{0.15}Al_{0.05}]O_2$ cathode particle was modified by lanthanum based oxide to improve electrochemical property and thermal stability. The XRD pattern of surface layer was indexed with that of $La_4NiLiO_8$. The discharge capacity of modified electrode was higher than that of pristine sample, specially at fast charge-discharge rate and high cut-off voltage. In the DSC profile of the charged sample, the generation of heat by exothermic reaction was decreased by surface modification. Such enhancement may by attributed to the presence of stable lanthanum based oxide, which effectively suppressd the reaction between electrode and electrolyte on the surface of $Li[Ni_{0.8}Co_{0.15}Al_{0.05}]O_2$ electrode.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.6
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• pp.610-617
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• 2017

This paper presents a study of the effect of thickness of porous Al-Ni electrodes, on the Hydrogen Evolution Reaction (HER) in alkaline media. As varying deposition time at 300 W DC sputtering power, the thickness of the Al-Ni electrodes was controlled from 1 to $20{\mu}m$. The heat treatment was carried out in $610^{\circ}C$, followed by selective leaching of the Al-rich phase. XRD studies confirmed the presence of $Al_3Ni_2$ intermetallic compounds after the heat treatment, indicating the diffusion of Ni from the Ni-rich phase to Al-rich phase. The porous structure of the Al-Ni electrodes after the selective leaching of Al was also confirmed in SEM-EDS analysis. The double layer capacitance ($C_{dl}$) and roughness factor ($R_f$) of the electrodes were increased for the thicker Al-Ni electrodes. As opposed to the general results in above, there were no further improvements of the HER activity in the case of the electrode thickness above $10{\mu}m$. This result may indicate that the $R_f$ is not the primary factor for the HER activity in alkaline media.

• Transactions of the Korean hydrogen and new energy society
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• v.7 no.1
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• pp.63-69
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• 1996

Effect of nickel powder to added to the hydrogen absorbing alloy electrode of $MmNi_{4.5}-xCoxMn_{0.3}Al_{0.2}$ system alloy was investigated. The addition of nickel powder was effective for the improvement of discharging characteristic. It was found that the discharge capacity was 310mAhig when the alloy negative electrode was mixed $MmNi_{3.75}CO_{0.75}Mn_{0.3}Al_{0.2}$ and nickel powder with a mix of one to three. Still another, we have investigated thermodynamic stability of hydrogen in the alloy negative electrode. As a result, enthalpy of hydrogen and hydrogen equilibrium pressure in the alloy negative electrode were a suitable value to easy hydrogen absorption-desorption.

• Journal of Electrochemical Science and Technology
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• v.4 no.1
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• pp.19-26
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• 2013

Graphene/Ni-Al layered double hydroxide (LDH) hybrid materials were synthesized by a hydrothermal reaction. Hexagonal Ni-Al LDH particles nucleated and grew on graphene sheets, thus preventing restacking of the graphene sheets and aggregation of the Ni-Al LDH nanoparticles upon drying. Electrode made from the graphene/Ni-Al LDH hybrid materials showed a substantial improvement in electrochemical capacitance relative to those made with pure Ni-Al LDH nanoparticles. In addition, the graphene/Ni-Al LDH hybrid composite materials showed remarkable stability after 4000 cycles with over 100% capacitance retention. These materials are thus very promising for use in electrochemical capacitor electrodes.

• Journal of Electrochemical Science and Technology
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• v.10 no.1
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• pp.82-88
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• 2019

Here, we report on nanocrystalline Si-Al-M (M = Fe, Cu, Ni, Zr) alloys for use as an anode for lithium-ion batteries, which were fabricated via a melt-spinning method. Based on the XRD and TEM analyses, it was found that the Si-Al-M alloys consist of nanocrystalline Si grains surrounded by an amorphous matrix phase. Among the Si-Al-M alloys with different metal composition, Ni-incorporated Si-Al-M alloy electrode retained the high discharge capacity of 2492 mAh/g and exhibited improved cyclability. The superior $Li^+$ storage performance of Si-Al-M alloy with Ni component is mainly responsible for the incorporated Ni, which induces the formation of ductile and conductive inactive matrix with crystalline Al phase, in addition to the grain size reduction of active Si phase.

• Journal of environmental and Sanitary engineering
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• v.16 no.2
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• pp.47-55
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• 2001

We investigated to find the optimum operation condition of electrolysis which have an influence on removal efficiency of heavy metals. When we experimented the testing wastewaters containing each 250mg/L of Cu and Ni ions, we got the variables like as pH, amount of electrolyte(NaCl), different species of electrode, electrode gap, electric strength, the number of electrodes, after fastening positive electrode plate with Al, Fe, Ti and negative electrode plate with Stainless Steel plate.

• Journal of the Korean Ceramic Society
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• v.33 no.11
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• pp.1231-1236
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• 1996

The electrode resistance of semiconducting PTC BaTiO3 ceramic material was studied in some detail. Comme-rical In-Ag paste In-Ga alloy and electroless plated Ni as well as evaporated Al were chosen as electrode. The contact resistance of electroded samples were measured by both dc resistivity and ac impedance analysis. The aging effect on contact resistance under cyclic loading from -1$0^{\circ}C$ to 85$^{\circ}C$ was also monitored for the prolonged period of time. In case of Al electroded samples the heat treatment and protective coating had effects on the stability against contact resistance degradation. It was also found that the samples with commercial In-Ag paste and electroless plated Ni electrode had good properties of contact resistance against aging.

• Transactions of the Korean hydrogen and new energy society
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• v.9 no.4
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• pp.161-167
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• 1998

It has been investigated the effects of alloying elements and binders on the corrosion behavior of metal hydride electrodes for anode of Ni/MH secondary battery. The $AB_5$-type alloys, $(LM)Ni_{4.49}Co_{0.1}Mn_{0.205}Al_{0.205}$ and $(LM)Ni_{3.6}Co_{0.7}Mn_{0.3}Al_{0.4}$, were used for the experiments. The electrodes were prepared by mixing and cold-pressing of alloy powders with Si sealent or PTFE powders, or cold-pressing the electroless copper coated alloy powders. The amount of copper coating was 20wt%. In order to examine corrosion behavior of the electrodes, the corrosion current and the current density, in 6M KOH aqueous solution after removal of oxygen in the solution, were measured by potentiodynamic and cyclic voltamo methods. The results showed that Co in the alloy increased corrosion resistance of the electrode whereas Ni decreased the stability of the electrode during the charge-discharge cycles. The electrode used Si sealant as a binder showed a lower corrosion current density than the electrode used PTFE and the electrode used Cu-coated alloy powders showed the best corrosion resistance.