Effect of atmosphere on the mechanical milling of natural graphite

Ong, Teng Sian; Yang, Hong

doi:10.1016/s0008-6223(00)00064-6

Cited by 176 publications

(115 citation statements)

References 23 publications

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“…The higher activity of CA-Ni-Pd composite is in agreement with studies that the carbon atoms with rounded shapes are the most reactive [40,41]. Sample CA-Ni-Pd has a slightly higher amount of particles with such shapes which suggests a better access of the electrolyte.…”

Section: Electrochemical Propertiessupporting

confidence: 88%

The effect of catalyst and heat treatment on the properties of carbon–metal composites

Osińska

2015

J Porous Mater

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Carbon gel and carbon-nickel-palladium doped gels (C-Ni-Pd) were prepared by carbonising resorcinol-formaldehyde (RF) hydrogel and resorcinolformaldehyde-nickel-palladium (RF-Ni-Pd) hydrogels at 900°C in a nitrogen atmosphere. RF and RF-Ni-Pd hydrogels were synthesized through sol-gel polycondensation followed by ambient drying. The aim of this study was the determination of the effect of heat treatment in air at 450°C on the properties of C-Ni-Pd gels prepared using different Pd salts. In the present work, Ni was added as acetate whereas Pd was added as acetate (CA-Ni-Pd) and as chloride (CB-Ni-Pd). Samples were examined by scanning electron microscopy and X-ray diffraction. Surface area was characterized by N 2 adsorption at -195.5°C. Thermogravimetric analysis was carried out in order to determine the thermal characteristics of carbon gel and nickel-palladium composites in air atmosphere. CANi-Pd composite had a higher activity and two-phase reaction compared to the CB-Ni-Pd composite. Further improvement of the electrolyte diffusion into the particles of nickel and palladium was obtained by oxidative thermal treatment. During this process a structural modification of the material took place, consequently leading to changes in the electrochemical properties of the composites.

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Section: Electrochemical Propertiessupporting

confidence: 88%

The effect of catalyst and heat treatment on the properties of carbon–metal composites

Osińska

2015

J Porous Mater

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“…Many NG's have been studied electrochemically to characterize their reversible capacity and first cycle irreversible capacity loss (ICL), or first cycle coulombic inefficiency. The dependence of performance on the particle size [1], surface area [2], surface modification [3,4], and mechanical milling [5,6], in various organic electrolytes has been studied, as well as the dependence on the composition of the electrolyte [7,8]. The ICL is due to primarily to the formation of a passivating solid electrolyte interface (SEI) layer by the decomposition of the electrolyte to form both as SEI layer and gaseous products on the surface of graphite during the initial charge/discharge cycles [9].…”

Section: Introductionmentioning

confidence: 99%

The dependence of natural graphite anode performance on electrode density

Shim

Striebel

2004

Journal of Power Sources

107

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The effect of electrode density for lithium intercalation and irreversible capacity loss on the natural graphite anode in lithium ion batteries was studied by electrochemical methods.Both the first-cycle reversible and irreversible capacities of the natural graphite anode decreased with an increase in the anode density though compression. The reduction in reversible capacity was attributed to a reduction in the chemical diffusion coefficient for lithium though partially agglomerated particles with a larger stress. For the natural graphite in this study the potentials for Li (de)insertion shifted between the first and second formation cycles and the extent of this shift was dependent on electrode density. The relation between this peak shift and the irreversible capacity loss are probably both due to the decrease in graphite surface area with compression.

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“…This indicates that the graphite is disordered as a result of ball milling, as previously reported. [8][9][10][11][12][13] The broadened peak corresponding to the (002) reflection peak is asymmetric and may be divided into two components, one of which might correspond to an interlayer spacing, d002, of 0.353 nm of relatively ordered graphite crystals, and another which relates to a larger interlayer spacing of lattice-damaged crystals.…”

Section: Resultsmentioning

confidence: 99%

“…On the other hand, mechanical milling of graphite is one possibility of producing disordered carbons, [8][9][10][11][12][13] in which the milling of graphite powder under drastic conditions or for long durations leads to highly disordered carbons with a particle size of few nanometers and nanosized crystallites.…”

Section: Introductionmentioning

confidence: 99%

Preparation and Characterization of Spherical Carbon Composite for Use as Anode Material for Lithium Ion Batteries

Ahn¹,

Lee

2010

Bulletin of the Korean Chemical Society

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A novel spherical carbon composite material, in which nanosized disordered carbons are dispersed in a soft carbon matrix, has been prepared and investigated for use as a potential anode material for lithium ion batteries. Disordered carbons were synthesized by ball milling natural graphite in air. The composite was prepared by mixing the ball-milled graphite with petroleum pitch powder, pelletizing the mixture, and pyrolyzing the pellets at 1200 o C in an argon flow. The ballmilled graphite consists of distorted nanocrystallites and amorphous phases. In the composite particle, nanosized flakes are uniformly distributed in a soft carbon matrix, as revealed by X-ray diffractometer (XRD) and transmission electron microscopy (TEM) experiments. The composite is compatible with a pure propylene carbonate (PC) electrolyte and shows high rate capability and excellent cycling performance. The electrochemical properties are comparable to those of hard carbon.

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Effect of atmosphere on the mechanical milling of natural graphite

Cited by 176 publications

References 23 publications

The effect of catalyst and heat treatment on the properties of carbon–metal composites

The effect of catalyst and heat treatment on the properties of carbon–metal composites

The dependence of natural graphite anode performance on electrode density

Preparation and Characterization of Spherical Carbon Composite for Use as Anode Material for Lithium Ion Batteries

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