Sains Malaysiana 47(2)(2018): 387-391

http://dx.doi.org/10.17576/jsm-2018-4702-21

 

Evaluation of La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ as a Potential Cathode for Proton-Conducting Solid Oxide Fuel Cell

(Penilaian La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ sebagai Potensi Katod untuk Sel Fuel Oksida Pepejal Pengkonduksi Proton)

 

Ismariza Ismail*, Nafisah Osman & Abdul Mutalib Md Jani

 

Faculty of Applied Science, Universiti Teknologi MARA, 02600 Arau, Perlis Indera Kayangan,

Malaysia

 

Diserahkan: 31 Ogos 2016/Diterima: 18 Januari 2017

 

 

ABSTRACT

The application of La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ (LSCF) as a potential cathode working on a BaCe_0.54Zr_0.36Y_0.1O_2.95 (BCZY) electrolyte for proton conducting solid oxide fuel cell was investigated. LSCF nanoceramic powders were synthesized by an activated carbon-assisted sol-gel process using metal nitrate-based chemicals. The LSCF powder was transformed to a slurry and spin-coated onto both surfaces of BCZY pellet to form a symmetrical cell with the configuration of LSCF|BCZY|LSCF. The symmetrical cell was subsequently sintered at 950^oC for 2 h to allow a good contact formation between electrode/electrolyte layers. The phase structural verification of the calcined powders was investigated by X-Ray diffractometer (XRD). Field-emission scanning electron microscopy (FESEM) was employed to examine the morphology of the sintered cell. The electrochemical behaviour of the symmetrical cell was studied by an electrochemical impedance spectroscopy. The formation of a single perovskite LSCF phase with a crystallite size of 20 nm was obtained at 700^oC as corroborated by XRD analysis. The FESEM images showed a good contact between LSCF cathode and BCZY electrolyte at electrode/electrolyte interfacial layer. The ASR obtained for LSCF symmetrical cell measured at 700^oC with and without Pt current collector is 0.87 and 31.25 Ωcm², respectively.

Keywords: Cathode material; morphology; proton-conducting solid oxide fuel cell

ABSTRAK

Kajian penggunaan La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ (LSCF) sebagai potensi katod ke atas elektrolit BaCe_0.54Zr_0.36Y_0.1O_2.95 (BCZY) untuk sel fuel oksida pepejal pengkonduksi proton telah dijalankan dalam penyelidikan ini. Serbuk nano seramik LSCF disintesis melalui kaedah sol-gel menggunakan bahan kimia berasaskan garam nitrat dibantu dengan serbuk karbon teraktif sebagai agen penyerakan partikel. Serbuk LSCF yang terhasil dijadikan sebagai dakwat katod dan disalutkan di atas permukaan pelet elektrolit dengan menggunakan teknik 'spin-coat' untuk menghasilkan sel simetri dengan konfigurasi LSCF|BCZY|LSCF. Sel simetri tersebut seterusnya disinter pada suhu 950^oC untuk menghasilkan sentuhan yang baik di lapisan antaramuka elektrod/elektrolit. Pengesahan struktur fasa serbuk yang dikalsinkan telah dikaji dengan menggunakan difraktometer sinar-X (XRD). Mikroskop imbasan elektron (FESEM) digunakan bagi mengkaji morfologi sel simetri yang telah disinter. Kajian sifat elektrokimia sel simetri dijalankan dengan menggunakan spektroskopi impedans. Analisis XRD menunjukkan bahawa pembentukan fasa perovskit tunggal LSCF dengan saiz kristalit 20 nm telah diperoleh pada suhu 700^oC. Imej FESEM mempamerkan sentuhan yang baik di antara lapisan katod LSCF dengan elektrolit BCZY di bahagian antaramuka elektrod/elektrolit. Rintangan luas permukaan yang didapati hasil pengukuran sel simetri LSCF pada suhu 700^oC dengan dan tanpa kehadiran Pt sebagai pengumpul arus masing-masing adalah 0.87 dan 31.25 Ω cm².

Kata kunci: Bahan katod; morfologi; sel fuel oksida pepejal pengkonduksi proton

 

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*Pengarang untuk surat-menyurat; email: ismariza85@gmail.com