Solid Solutions of LiCo1−xNixO2 (x=0,0.1,…,0.9) Obtained via a Combustion Synthesis Route and Their Electrochemical Characteristics

Pure, single-phase and layered LiCo1−xNixO2 materials with good cation ordering are not easy to synthesize. In this work, solid solutions of LiCo1−xNixO2 (x = 0, 0.1, …, 0.9) are synthesized using a self-propagating combustion route and characterized. All the materials are observed to be phase pure giving materials of hexagonal crystal system with R-3m space group. The RIR and R factor values of stoichiometries of LiCo1−xNixO2 (x = 0.1, 0.2, 0.3, 0.4, and 0.5) show good cation ordering. Their electrochemical properties are investigated by a series of charge-discharge cycling in the voltage range of 3.0 to 4.3 V. It is found that some of the stoichiometries exhibit specific capacities comparable or better than those of LiCoO2, but the voltage plateau is slightly more slopping than that for the LiCoO2 reference material.

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Overlithiation of LiNi0.8Co0.2O2 for Increased Performance in Li-Ion Batteries

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.938.253 ◽

2014 ◽

Vol 938 ◽

pp. 253-256

Author(s):

Hashlina Rusdi ◽

Norlida Kamarulzaman ◽

Rusdi Roshidah ◽

Kelimah Elong ◽

Abd Rahman Azilah

Keyword(s):

Cathode Materials ◽

Structural Instability ◽

Cation Ordering ◽

Capacity Fading ◽

Capacity Retention ◽

Battery Capacity ◽

Li Ion ◽

Battery Application ◽

Charge Discharge ◽

Better Than

Layered LiNi1-xCoxO2 is one of the promising cathode materials for Li-ion battery application. However, the Ni rich cathode materials exhibit low capacity and bad capacity retention. This is due to factors such as disorder and structural instability when Li is removed during charge-discharge. Overlithiation of cathode materials is expected to improve the cation ordering and structural stability. Good cation ordering will increase the battery capacity. During charge-discharge, the irreversible Li+ loss can be replaced to a certain extent by the interstitial Li+ ions in the lattice of the LixNi0.8Co0.2O2 material. This helps reduce capacity fading of the cathode materials. In this work the overlithiation of LiNi0.8Co0.2O2 is done by interstitially doping Li+ in the LiNi0.8Co0.2O2 materials producing Li1.05Ni0.8Co0.2O2 and Li1.1Ni0.8Co0.2O2. Results showthat the performance of the overlithiated LiNi0.8Co0.2O2 materials is better than pure LiNi0.8Co0.2O2.

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Synthesis, Characterization and Charge-Discharge Profile of LiMn0.3Co0.3Ni0.3Fe0.1O2 Prepared via Sol-Gel Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.501.56 ◽

2012 ◽

Vol 501 ◽

pp. 56-60 ◽

Cited By ~ 2

Author(s):

Jaafar Mohd Hilmi ◽

Mohamed Nor Sabirin ◽

Rosiyah Yahya ◽

Norlida Kamarulzaman

Keyword(s):

Sol Gel ◽

Layered Compounds ◽

Electrochemical Characteristics ◽

Voltage Range ◽

Gel Method ◽

Sol Gel Method ◽

Cost Constraints ◽

A Charge ◽

Discharge Profile ◽

Charge Discharge

LiCoO2 is a well established commercial Li-ion battery cathode. However, due to cost constraints and the toxicity of the metal, other layered compounds should be investigated. In this paper, layered LiMn0.3Co0.3Ni0.3Fe0.1O2 were prepared using sol-gel method with CH3COOLi•2H2O, (CH3CO2)2Mn•4H2O, (CH3CO2)2Co•4H2O, (CH3CO2)2Ni•4H2O and Fe (NO3)3•9H2O as starting materials. The sample was characterized by simultaneous thermogravimetric analysis, x-ray powder diffraction and scanning electron microscopy. The electrochemical characteristics were studied by a charge-discharge cycle done on the fabricated cell using a charge current of 1.0 mA and a discharge current 0.5 mA between 4.2 and 0.5 V. The XRD results showed that the layered LiMn0.3Co0.3Ni0.3Fe0.1O2 were of pure phase with discharge capacity of about 136 mAhg-1. The batteries were then subjected to a series of charge-discharge cycling in the voltage range of 2.5 to 4.2 V. The results showed there was little loss of capacity after 10 cycles.

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Materials Characterization and Charge-Discharge Profile of LiNi1-XCoxO2 Cathodic Materials for Li-Ion Battery Application

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.545.182 ◽

2012 ◽

Vol 545 ◽

pp. 182-184

Author(s):

Kelimah Elong ◽

Rusdi Roshidah ◽

Nurul Atikah Mohd Mokhtar ◽

Azira Azahidi ◽

Norlida Kamarulzaman

Keyword(s):

Electrochemical Properties ◽

Thermal Studies ◽

Active Material ◽

Cobalt Content ◽

Combustion Method ◽

Composite Cathode ◽

Partial Substitution ◽

Electrochemical Characteristics ◽

Voltage Range ◽

Charge Discharge

Mixed lithium nickel cobalt oxides are advantageous over LiCoO2due to decrease in cobalt content in the material. It is also better than LiNiO2which is known to be difficult to synthesize and has poor electrochemical properties. Partial substitution of nickel in lithium nickel oxide with cobalt significantly improves its electrochemical properties. In this work, a combustion method was used for synthesis of LiNi1-xCoxO2(x= 0.1 and 0.2). The starting materials used are nitrates of the metals or transition metals. The precursors obtained are used for thermal studies. The precursors of LiNi1-xCoxO2were annealed at a temperature of 700 °C for 24h. X-ray diffraction (XRD) showed that the materials are pure. A composite cathode comprising of the cathode active material, binder and graphite was fabricated. Charge-discharge profiles of the materials with a voltage range of 0.5 V - 4.5 V vs Li/Li+ were obtained in order to study their electrochemical characteristics. The materials exhibited several voltage plateaus attributed to different electrochemical reactions.

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Improved Electrochemical Performance of LiCoPO4 Nanoparticles for Lithium Ion Batteries

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2007.078 ◽

2007 ◽

Vol 7 (11) ◽

pp. 4037-4040 ◽

Cited By ~ 8

Author(s):

Hal-Bon Gu ◽

Bo Jin ◽

Dae-Kyoo Jun ◽

Zhenji Han

Keyword(s):

Single Phase ◽

Coulombic Efficiency ◽

Lithium Ion ◽

Structural Performance ◽

X Ray Diffraction ◽

Voltage Range ◽

X Ray ◽

Li Battery ◽

Li Batteries ◽

Charge Discharge

Single phase LiCoPO4 nanoparticles were synthesized by solid-state reaction. LiCoPO4/Li batteries were fabricated in an argon-filled glove box, and their electrochemical properties were analyzed by cyclic voltammetry (CV) and charge–discharge tests. The structural performance of LiCoPO4 nanoparticles was investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM). The XRD result demonstrated that LiCoPO4 nanoparticles had an orthorhombic olivine-type structure with a space group of Pmnb. The charge–discharge tests indicated that the initial discharge capacity and coulombic efficiency of LiCoPO4/Li batteries were 110 mA h/g and 48% in cut-off voltage range of 3.0–5.3 V,90 mA h/g and 54% in cut-off voltage range of 3.0–5.1 V, 70 mA h/g and 60% in cut-off voltage range of 3.0–5.0 V, respectively. After 30 cycles, the coulombic efficiency was 78% for 3.0–5.3 V, 88% for 3.0–5.1 V, 91% for 3.0–5.0 V, respectively. These results indicated that the coulombic efficiency of LiCoPO4 /Li battery increased upon cycling and upon decreasing in charge upper limit voltage, respectively.

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Effect of Ferrite Volume Fraction on Mechanical Properties of X80 Pipeline Steel

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.989-994.212 ◽

2014 ◽

Vol 989-994 ◽

pp. 212-215

Author(s):

J. Liu ◽

G. Zhu ◽

W. Mao

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Work Hardening ◽

Single Phase ◽

Volume Fraction ◽

Pipeline Steel ◽

X80 Pipeline Steel ◽

Hardening Behavior ◽

Two Phases ◽

Better Than

The effect of volume fraction of ferrite on the mechanical properties including strength, plasticity and wok hardening was systematically investigated in X80 pipeline steel in order to improve the plasticity. The microstructures with different volume fraction of ferrite and bainite were obtained by heat-treatment processing and the mechanical properties were tested. The work hardening behavior was analyzed by C-J method. The results show that the small amount of ferrite could effectively improve the plasticity. The work hardening ability and the ratio of yield/tensile strength with two phases of ferrite/bainite would be obviously better than that with single phase of bainite. The improvement of plasticity could be attributed to the ferrite in which more plastic deformation was afforded.

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Electrochemical hydrogenation, lithiation and sodiation of the GdFe2–xMx and GdMn2–xMx intermetallics

Voprosy Khimii i Khimicheskoi Tekhnologii ◽

10.32434/0321-4095-2021-135-2-139-149 ◽

2021 ◽

pp. 139-149

Keyword(s):

Electrode Materials ◽

Electrochemical Impedance ◽

Diffraction Method ◽

Electrochemical Characteristics ◽

Electrochemical Hydrogenation ◽

Hydrogen Atoms ◽

X Ray ◽

Cell Parameters ◽

The Difference ◽

Better Than

Electrochemical hydrogenation, lithiation and sodiation of the phases GdFe2–xMx and GdMn2–xMx (M=Mn, Co, Ni, Zn, and Mg) and the influence of doping components on electrochemical characteristics of electrode materials on their basis were studied using X-ray powder diffraction method, scanning electron microscopy, energy dispersive X-ray analysis, X-ray fluorescent spectroscopy, cyclic voltammetry and electrochemical impedance spectroscopy. Phase analysis showed a simple correspondence between unit cell parameters of the phases and atomic radii of doping elements. Electrode materials based on GdFe2 and GdMn2 doped with 2 at.% of Co, Ni and Mg demonstrated better hydrogen sorption properties than those doped with Mn and Zn. Corrosion resistance of the doped electrodes was also better than of the binary analogues (e.g. corrosion potential of the GdFe2-based electrode was –0.162 V whereas that of GdFe1.96Ni0.04 was –0.695 V). The capacity parameters were increased in the following ranges: Zn<Mn<Mg<Co<Ni and Zn<Fe<Mg<Co<Ni for GdFe2–xMx and GdMn2–xMx, respectively. After fifty cycles of charge/discharge, we observed the changes in surface morphology and composition of the electrode samples. In the structure of studied Laves type phases with MgCu2-type structure, the most suitable sites for hydrogen atoms are tetrahedral voids 8a. During lithiation and sodiation of the phases, the atoms of the M-component of the structure are replaced by the atoms of lithium, and the atoms of gadolinium are replaced by the atoms of sodium. This difference in interaction is due to the difference in atomic sizes of the atoms. No insertion of lithium or sodium into the structural voids of the phases was observed.

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High Accuracy Measurement of Total Losses in Fractional Horsepower Induction Motors

International Journal of Advanced Research in Engineering ◽

10.24178/ijare.2015.1.2.13 ◽

2015 ◽

Vol 1 (2) ◽

pp. 13

Author(s):

Azzeddine Ferrah ◽

Mounir Bouzguenda ◽

Jehad M. Al-Khalaf Bani Younis

Keyword(s):

Single Phase ◽

Induction Motors ◽

Data Acquisition System ◽

High Accuracy ◽

Industrial Applications ◽

Motor Speed ◽

Accuracy Measurement ◽

Three Phase ◽

Better Than ◽

High Accuracy Measurement

Large and small single-phase and three-phase induction motors are commonly used in industrial applications. The present work represents an attempt towards the design of a high accuracy system for the measurement of fractional horsepower (FHP) induction motor losses and efficiency. The calorimeter designed and built is capable of measuring heat losses of up to 1 kW with an overall accuracy better than 3%. During all tests, ambient temperature, humidity, motor speed and motor frame temperature were recorded using precise digital instruments. The inlet, outlet temperatures and resulting losses were recorded automatically using a high accuracy 12-bit data acquisition system. The preliminary results obtained demonstrate the suitability of the designed calorimeter for the accurate measurement of losses in FHP induction motors.

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