Now showing 1 - 3 of 3
  • Publication
    Characterization of LSCF cathode material modified with f-CNTs
    (Trans Tech Publications Ltd., 2020-07)
    Nurul Izzati Abd Malek
    ;
    ;
    Nafisah Osman
    Cathode is one of the important parts in performing the high efficiency of proton conducting fuel cell (PCFC). Selection of appropriate cathode material may resolve the major drawbacks at the cathode part associated with the high Rp. Accordingly, tremendous effort have been done to reduce the Rp and one of the alternatives is the modification of cathode microstructure that can be achieved by introducing dispersing agent in the synthesis route. Thus, in this present work, a functionalized carbon nanotubes (f-CNTs) obtained from acidification process was used as a dispersing agent in the synthesis of La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) cathode material. The amount of 4 mg, 8 mg and 12 mg of f-CNTs were respectively added to LSCF cathode during the synthesizing process by a sol-gel method. Semi-solid gel obtained was calcined at 900 ˚C to form high purity of LSCF powder and respectively denoted as LSCF4, LSCF8 and LSCF12. The powder was characterized by Fourier Transform Infrared (FTIR) Spectroscopy, Pycnometer, Particle Size Analyzer and Scanning Electron Microscopy with Energy Dispersive X-ray (SEM/EDX). The FTIR analysis depicted the peak of respective metal complexes, metal oxide, symmetrical and asymmetrical stretching of carboxylate. The pycnometer showed the lowest density of LSCF4 was 2.8777 g/cm3. The Particles Size Analyzer confirmed the particle size of 38 nm ultrafine powder for LSCF4. The SEM image depicted the highly disperse spherical particles found in LSCF4 with particle size about 30 nm. The elemental composition of the samples is comparable with the nominal stoichiometric of LSCF4 as corroborated by the EDX analysis. Therefore, the LSCF with optimum 4 mg f-CNTs as dispersing agent has potential as nanoporous cathode material for proton conductivity fuel cell.
  • Publication
    Development of MCSF (M=La, Ba) cathode materials for proton conducting fuel cell application
    (AIP Publishing, 2020-03)
    Nafisah Osman
    ;
    Nurul Izzati Abd Malek
    ;
    ;
    Anisah Shafiqah Habiballah
    ;
    Abdul Mutalib Md Jani
    Two cathode materials for proton-conducting fuel cell (PCFC), La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) and Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) were investigated regarding their microstructural and electrical properties under air containing atmosphere. The respective sample was prepared via a modified sol-gel method using an activated carbon as a dispersing agent and anodic aluminium oxide (AAO) templating method assisted with sol-gel process. The powders were subjected to X-ray Diffractometer (XRD) and Brunauer-Emmet-Teller (BET). A symmetrical half-cell of LSCF|BCZY|LSCF and BSCF|BCZY|BSCF (BCZY = BaCe0.54Zr0.36Y0.1O2.95)was fabricated and characterized using an electrochemical impedance spectroscopy (EIS) and scanning electron microscope (SEM). After calcined at T = 900 °C, both of the LSCF and BSCF demonstrated their single-phase structure and exhibited highly dispersed powders with large surface area as proven by BET result. For electrical analyses, impedance spectrum of the cathodes was referred only to the two main contributions of cathode responses which were charge transfer at cathode/electrolyte interface and oxygen adsorption/dissociation on the cathode surface. At 600 °C, the polarization resistance of LSCF half-cell (Rp = 4.94 ω.cm2) was comparable to BSCF (Rp = 4.50 ω.cm2). SEM images revealed no delamination along the electrolyte/ electrode interface after EIS measurements as no sign of crack was observed for both samples. It can be concluded that the microstructure of the cathode layer can be tailored by altering the sample's preparation route which in turn to enhance the PCFC performance.
  • Publication
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