Ismariza Ismail
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Preferred name
Ismariza Ismail
Official Name
Ismail, Ismariza
Alternative Name
Ismail, I.
Ismail, Ismariza
Main Affiliation
Scopus Author ID
57203013485
Researcher ID
GTH-8854-2022

Research Output
Now showing 1 - 6 of 6
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Characterization of LSCF cathode material modified with f-CNTs

2020-07 , Nurul Izzati Abd Malek , Ismariza Ismail , 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.

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Banana stem waste as a sustainable modifier for microstructure modification of protonic ceramic fuel cell cathode

2024-06 , Ismariza Ismail , Muhammad Mahyiddin Ramli , Norizah Abd Karim , Abdullah Abdul Samat

This study investigates the feasibility of utilizing banana stem waste (BSW) as a pore former to modify the microstructure of the PCFC composite cathode. The microstructure of the La₀.₆Sr₀.₄Co₀.2Fe₀.8O3-α-Ba(Ce₀.₆Zr₀.₄)₀.₉Y₀.1O3-δ (LSCF-BCZY64) composite cathode was modified by varying the amounts of the incorporated banana stem waste. The samples underwent sintering at 1000 ˚C, and their microstructural and physical properties were analyzed using X-ray diffraction, scanning electron microscopy, and densimeter. The results indicate that the incorporation of BSW enhances the porosity of the cathode without significantly affecting its crystalline structure. As the amount of BSW increased from 10 to 40 wt.%, the porosity level increased from 7.0% to 32.7%, and the density of the samples decreased from 1.3 to 0.9 g/cm3, thereby supporting the results of the porosity analysis. Increased cathode porosity can enhance reactant accessibility to active sites, potentially resulting in improved cell performance and durability. Moreover, the utilization of BSW as a sustainable and cost-effective pore former aligns with the growing emphasis on environmentally friendly materials in energy applications.

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Development of MCSF (M=La, Ba) cathode materials for proton conducting fuel cell application

2020-03 , Nafisah Osman , Nurul Izzati Abd Malek , Ismariza Ismail , 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.

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Characterization of LaSrCoFeO₃ cathode material prepared with the aid of functionalized carbon nanotubes for proton conducting fuel cell

2020 , Nurul Izzati Abd Malek , Ismariza Ismail , Abdul Mutalib Md Jani , Nafisah Osman

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Biomass Waste Incorporation in La₀.₆Sr₀.₄Co₀.₂Fe₀.₈O₃-α˗Ba(Ce₀.₆Zr₀.₄)₀.₉Y₀.1O₃-δ composite cathode: effects on microstructural and physical properties

2025 , Ismariza Ismail , Nur Ashafieka Abdullah , Norizah Abd Karim , Shazlina Johari , Muhammad Mahyiddin Ramli

This study explores the incorporation of rice straw as a pore-forming agent in fabricating the Laâ‚€.₆Srâ‚€.â‚„Coâ‚€.â‚‚Feâ‚€.₈O₃-α˗Ba(Ceâ‚€.₆Zrâ‚€.â‚„)â‚€.₉Yâ‚€.1O₃–δ (LSCF-BCZY) composite cathode, focusing on its microstructural and physical properties. Conventional cathode materials often face challenges in balancing porosity and structural stability, with synthetic pore formers posing environmental and consistency concerns. To address these issues, rice straw was introduced into the cathode matrix at varying weight percentages, and the composites were sintered at 1000 Â°C. The addition of rice straw was evaluated using X-ray diffraction, scanning electron microscopy, and densitometry. The results revealed that increasing rice straw content significantly enhanced cathode porosity, rising from 5.53 to 27.74%, with a concomitant reduction in density from 1.33 to 0.93 g/cm3, while maintaining the crystalline stability of the LSCF-BCZY composite. Enhanced porosity suggests improved reactant diffusion to active sites, potentially benefiting the cell's performance in future energy applications. This work highlights the potential of agricultural waste as a sustainable and effective alternative to synthetic pore formers in cathode fabrication.

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La₀.₆Sr₀.₄Co₀.₂Fe₀.₈O₃−δ powder: a simple microstructure modification strategy for enhanced cathode electrochemical performance

2020 , Ismariza Ismail , Nafisah Osman , Abdul Mutalib Md Jani

A simple strategy of producing well-dispersed La₀.₆Sr₀.₄Co₀.₂Fe₀.₈O₃−δ (LSCF) cathode nanopowders that utilizes a dispersing agent is presented. The cathode nanopowder was synthesized by employing a dispersing agent-assisted sol–gel method. Two types of dispersing agents were applied as the synthesizing aids in this study which are the activated carbon (AC) and ethylene glycol (EG). The synthesized cathode powder was systematically characterized by X-ray diffraction (XRD), thermogravimetric analyzer (TGA), field emission scanning electron microscopy (FESEM), and BET surface area analyzer. The electrochemical properties of the fabricated cell were evaluated using electrochemical impedance spectroscopy (EIS). TGA analysis shows that both dispersing agents decomposed below 600 °C. The XRD analysis demonstrates that the single-phase LSCF perovskite is attainable at the calcination temperature of 700 °C for 5 h. FESEM results are in accordance with the BET analysis in which application of the dispersing agents produced more dispersed cathode powders and larger surface area. The electrochemical performances of the LSCF cathode modified with the AC and EG are respectively in the average of six- and eightfolds higher as compared with the pristine LSCF. The dispersing reaction of AC and EG and their influences on the cathode microstructure and performance are also thoroughly discussed.

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