Surface modification of natural vein graphite for the anode application in Li-ion rechargeable batteries

Amaraweera, T. H. N. G.; Balasooriya, N.W.B.; Wijayasinghe, H.W.M.A.C.; Attanayake, A. N. B.; Mellander, Bengt-Erik; Dissanayake, M.A.K.L.

doi:10.1007/s11581-018-2523-5

Cited by 17 publications

(19 citation statements)

References 24 publications

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“…FT-IR spectra of NPG variety of vein graphite before and after the mild oxidation are shown in Fig 1. The vibrational bands correspond to ν C=O stretching at 1720-1680 cm -1 , ν O-H stretching at 1360 cm -1 and ν C-O stretching at 1260-1000 cm -1 are predominant in the mildly oxidized graphite surface (Ein-Eli and Koch, 1997). These bands are very similar to those published in earlier (Amaraweera et al, 2014(Amaraweera et al, , 2018. Therefore, the FT-IR spectra of four morphological varieties confirm the formation of acidic groups or an oxidized layer on the surface of vein graphite after the mild oxidation with H 2 O 2 .…”

Section: Surface Modification Of Vein Graphitesupporting

confidence: 87%

“…The intensity of absorption peaks representing carbonyl groups and C-O acid group of mildly oxidized vein graphite with H 2 O 2 is relatively weak compared to that of mild oxidized vein graphite with (NH 4 ) 2 S 2 O 8 (Amaraweera et al, 2013(Amaraweera et al, , 2014(Amaraweera et al, , 2018. This may be due to the weak oxidation ability of As shown in Fig.…”

Section: Surface Modification Of Vein Graphitementioning

confidence: 91%

“…Mild oxidation has not caused any adverse effect on the electronic properties of graphite (Amaraweera et al, 2018). This resultant conductivity is sufficient for the anode application in LIB.…”

Section: Fig 1 Ft-ir Spectra Of the Purified Npg Before And After Mmentioning

confidence: 92%

“…This may be due to the weak oxidation ability of As shown in Fig. 2, the purely hexagonal structure of graphite samples could be maintained during the oxidation reaction with H 2 O 2 similar to other strong chemical oxidants such as (NH 4 ) 2 S 2 O 8 , HNO 3 and HF (Ein-Eli and Koch, 1997;Wu et al, 2002Xiaowei et al, 2004;Balasooriya et al, 2006;Fu et al, 2006;Amaraweera et al, 2014Amaraweera et al, , 2018Hewathilake et al, 2017). Further, mild oxidation process did not involve the formation of an intermediary graphite intercalation compound or other secondary phases (JCPDS: 75-1621).…”

Section: Surface Modification Of Vein Graphitementioning

confidence: 97%

“…Use of strong chemical oxidants such as (NH 4 ) 2 S 2 O 8 , HNO 3 and HF is identified as a successful method for surface modification of natural graphite (Ein-Eli and Koch, 1997;Wu et al, 2002Xiaowei et al, 2004;Balasooriya et al, 2006;Fu et al, 2006;Amaraweera et al, 2014Amaraweera et al, , 2018Hewathilake et al, 2017). Those strong chemicals are hazardous and highly toxic substances.…”

Section: Introductionmentioning

confidence: 99%

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Preparation of vein graphite anode materials by eco-friendly mild oxidation, for lithium-ion rechargeable batteries

Amaraweera

Pynthamil

Wijayasinghe

et al. 2019

J. Geol. Soc. Sri Lanka

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Vein graphite with high purity and crystallinity has been identified as a cost-effective source to produce anode material. High anisotropy of graphite surface and impurities in trace levels cause profound alteration of electrochemical activities in Lithium-ion Rechargeable Batteries (LIBs). Surface modification with strong chemical oxidant such as (NH 4) 2 S 2 O 8 , HNO 3 and HF, which are highly toxic and hazardous is identified as a successful method to modify the graphite as an anode material. Therefore, an eco-friendly approach to modify the vein graphite surface was investigated in this study. Purified needle platy graphite was treated with H 2 O 2 solution at 60°C for 24 hours. FT-IR spectra and Powder X-ray diffraction (PXRD) patterns oxidized graphite indicate the formation of acidic groups or an oxidized layer without affecting the crystallographic structure of graphite due to mild oxidation with H 2 O 2. In addition, Thermogravimetric Analysis (TGA) and Scanning Electron Microscopic (SEM) images provided results suggesting that the oxidation eliminates some reactive structural defects in vein graphite. The electrochemical properties of the graphite electrodes were studied with the assembled CR 2032 coin cells. The charge, discharge study of the assembled cells , carried out at C/5 rate with a cutoff voltage of 0.002-1.5 V at room temperature indicate a considerable improvement in the overall electrochemical performance of the graphite electrode material prepared by mild oxidation using H 2 O 2 as the oxidant. This enhancement of electrochemical performance may results due to the improved graphite surface structure formed by the H 2 O 2 mild oxidation process used in this study. Mild oxidation of vein graphite with H 2 O 2 is ecofriendly and cost-effective method since water is the by-product of the oxidation process carried out at low temperature.

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Section: Surface Modification Of Vein Graphitesupporting

confidence: 87%

Section: Surface Modification Of Vein Graphitementioning

confidence: 91%

Section: Fig 1 Ft-ir Spectra Of the Purified Npg Before And After Mmentioning

confidence: 92%

Section: Surface Modification Of Vein Graphitementioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

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Preparation of vein graphite anode materials by eco-friendly mild oxidation, for lithium-ion rechargeable batteries

Amaraweera

Pynthamil

Wijayasinghe

et al. 2019

J. Geol. Soc. Sri Lanka

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High‐Performance Natural Graphite Anode for Lithium‐Ion Batteries: Using TiO₂ as an Additive

et al. 2022

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In this study, an attempt has been made to improve the performance of natural graphite anode using TiO 2 nanoparticles additive. In this method, high-performance electrodes have been achieved by addition of TiO 2 nanoparticles to base graphite active material, which is able to offer supplementary effects. TiO 2 emulsions with different concentrations of 10 %, 20 %, and 100 % are applied to prepare the binder solvent. The graphite anode made with 10 % concentration of TiO 2 emulsion (NGÀ T10) shows the best performance in comparison with other samples. The Nano-scale images of the scanning electron microscope (SEM) affirm the existence of a uniform coating on the surface of the natural graphite particles for the NGÀ T10 electrode. Energy-dispersive X-ray (EDX) spectroscopy on the NGÀ T10 sample clearly indicates the Ti element signal.According to atomic force microscopy (AFM) images, an increment in surface roughness can provide a more effective surface and improve wettability, resulting in better electrochemical performance of NGÀ T10. The charge-discharge test of the NGÀ T10 half-cell represents an excellent cycle performance without any capacity degradation during 100 cycles at 0.5 C. However, the value of capacity retention for bare natural graphite (BNG) is 90.7 % in the same conditions. The electrochemical impedance spectroscopy (EIS) results indicate that the existence of TiO 2 nanoparticles in NGÀ T10 improves the resistance of solid electrolyte interface (SEI) film and chargetransfer resistance. The NGÀ T10 also enhances the pouch cell capacity at various current densities up to 4 C.

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Effect of modifier on battery studies of silver-based FIC glasses

Kumar

Rao

Veeraiah

et al. 2018

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Surface modification of natural vein graphite for the anode application in Li-ion rechargeable batteries

Cited by 17 publications

References 24 publications

Preparation of vein graphite anode materials by eco-friendly mild oxidation, for lithium-ion rechargeable batteries

Preparation of vein graphite anode materials by eco-friendly mild oxidation, for lithium-ion rechargeable batteries

High‐Performance Natural Graphite Anode for Lithium‐Ion Batteries: Using TiO₂ as an Additive

Effect of modifier on battery studies of silver-based FIC glasses

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Surface modification of natural vein graphite for the anode application in Li-ion rechargeable batteries

Cited by 17 publications

References 24 publications

Preparation of vein graphite anode materials by eco-friendly mild oxidation, for lithium-ion rechargeable batteries

Preparation of vein graphite anode materials by eco-friendly mild oxidation, for lithium-ion rechargeable batteries

High‐Performance Natural Graphite Anode for Lithium‐Ion Batteries: Using TiO2 as an Additive

Effect of modifier on battery studies of silver-based FIC glasses

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Product

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About

High‐Performance Natural Graphite Anode for Lithium‐Ion Batteries: Using TiO₂ as an Additive