Mohd Sobri Idris
Thumbnail Image
Preferred name
Mohd Sobri Idris
Official Name
Mohd Sobri , Idris
Alternative Name
Idris, Mohd Sobri
Idris, M. Sobri
Idris, M. S.
Main Affiliation
Scopus Author ID
55898869500
Researcher ID
G-2128-2010

Research Output

Filters

2 1
2
Reset filters

Settings
Now showing 1 - 2 of 2
  • Publication
    Influence of heating temperature on structure, morphology and electrochemical performance of LiV₃O₈ cathode for lithium-ion batteries application
    (Trans Tech Publications Ltd., 2020)
    Mohamad Izha Ishak
    ;
    Khairel Rafezi Ahmad
    ;
    Rozana Aina Maulat Osman
    ;
    Mohd Sobri Idris
    LiV₃O₈ layered structure was successfully synthesized by a conventional solid-state approach and subsequent heat-treated at 400, 450, 500 and 550 ºC. The samples were characterized by XRD, SEM, TEM, BET. Electrochemical performance of LiV₃O₈ was investigated by cyclic voltammetry (CV) and galvanostatic charge-discharge. The results showed that high purity of LiV3O8 with layered structure was formed. The morphology of the samples were mixed between nanorods and nanosheets structure. For electrochemical performance, results showed that LiV₃O₈ heat-treated at 500 ºC performed a highest charge and discharge capacity of 212 and 172 mAh g-1, respectively. From electrochemical performance results made them a good candidate for cathode material for lithium-ion batteries application.
  • Publication
    The effect of cation ordering on the structure, electrical and electronic properties of cubic spinel LiNi₀.₅Mn₁.₅O₄
    ( 2025-01)
    Edi Yasa Ardiansyah
    ;
    Mohd Sobri Idris
    ;
    Rozana Aina Maulat Osman
    ;
    Fahmi Fahmi
    In this paper, we present the investigation of the impact of cation ordering on the structural, electrical, and electronic properties of a cubic spinel LiNi₀.₅Mn₁.₅O₄. Rietveld refinement using X-ray diffraction (XRD) data reveals that LiNi₀.₅Mn₁.₅O₄ annealed at 700 °C adopts a well-ordered atomic arrangement in cubic spinel (SG = P4332). Then, it is transformed to a disordered cubic spinel (SG = Fd-3m) at higher temperatures (> 800 °C). Impedance spectroscopy is employed to evaluate the dielectric and electrical properties in the temperature range of 0 to 25oC within the frequency range between 10 Hz and 100 kHz. The Cole-Cole plot indicates that grain boundaries contribute significantly to electrical conductivity and that bulk resistance decreases with increasing temperature. The AC conductivity analysis shows that the electrical conductivity of well-ordered and disordered cubic spinel LiNi₀.₅Mn₁.₅O₄ exhibits thermal activation and obeys Jonscher's universal power law. Furthermore, the electronic properties of cubic spinel LiNi₀.₅Mn₁.₅O₄ with the space groups of Fd-3m and P4332 are investigated using the density functional theory (DFT) plane-wave method. The electronic analysis of the cubic spinel LiNi₀.₅Mn₁.₅O₄ (SG = Fd-3m) indicates stronger bonding between oxygen and transition metal elements compared to the LiNi₀.₅Mn₁.₅O₄ (SG = P4332) structure. Therefore, LiNi₀.₅Mn₁.₅O₄ with the Fd-3m space group exhibits high structural stability, making it a favourable cathode material for high-voltage rechargeable lithium-ion batteries.
      16  2