Sains Malaysiana 40(7)(2011): 701–705

Ionic Conductivity of PEMA-LiClO₄ Polymer Electrolytes

(Kekonduksian Ion dalam Elektrolit Polimer PEMA-LiClO₄)

S.N. Amir

Department of Engineering, Centre for Foundation Studies, International Islamic

University of Malaysia, 46350 Petaling Jaya, Selangor, Malaysia

R. Othman

Department of Sciences, Kuliyyah of Engineering, International Islamic

University of Malaysia, Jalan Gombak, 53100 Kuala Lumpur, Malaysia

R.H.Y. Subban

Faculty of Applied Sciences, Universiti Teknologi MARA

40450 Shah Alam, Selangor, Malaysia

N.S. Mohamed*

Centre for Foundation Studies in Science, University of Malaya

50603 Kuala Lumpur, Malaysia

Diserahkan: 23 OKtober 2009 / Diterima: 20 September 2010

ABSTRACT

Solid polymer electrolytes comprised of various weight percent ratios of poly(ethyl methacrylate) (PEMA) and lithium perchlorate (LiClO4) salt were prepared via solution casting technique using N,N-dimethylformamide (DMF) as the solvent. The conductivity values of the electrolytes were determined via impedance spectroscopy. The conductivity of the PEMA-LiClO4 electrolytes increased with increasing salt concentration and the highest conductivity obtained was in the order of 10-6 S cm-1 at salt concentration of 20 wt%. The conductivity decreased for higher salt concentration. In order to understand the conductivity behavior, XRD and dielectric studies were done. The results showed that the conductivity was influenced by the fraction of amorphous region and number of charge carriers in the system. The transference number measurement was also performed on the highest conducting electrolyte systems. The result of the measurement indicated that the systems were ionic conductors.

Keywords: Dielectric constant; impedance spectroscopy; Scherrer length

ABSTRAK

Elektrolit polimer pepejal yang mengandungi pelbagai nisbah peratus berat poli(etil metakrilat) (PEMA) dan garam litium perklorat (LiClO4) telah disediakan melalui teknik pengacuan larutan dengan menggunakan N,N-Dimetilformamida (DMF) sebagai pelarut. Nilai kekonduksian elektrolit telah ditentukan dengan spektroskopi impedans. Kekonduksian elektrolit PEMA-LiClO4 meningkat dengan peningkatan kepekatan garam dan kekonduksian yang paling tinggi di dapati adalah di dalam julat 10-6 S cm-1 pada 20 peratus berat kepekatan garam. Kekonduksian menurun pada kepekatan garam yang lebih tinggi. Untuk memahami sifat kekonduksian ini, pembelaun sinar-X dan kajian dielektrik telah dilakukan. Keputusan menunjukkan bahawa kekonduksian dipengaruhi oleh bahagian kawasan amorfus dan nombor pembawa cas di dalam sistem. Pengukuran nombor pemindahan ion pada sistem elektrolit yang mempunyai kekonduksian paling tinggi juga telah dibuat. Keputusan pengukuran menunjukkan bahawa sistem adalah konduktor ion.

Kata kunci: Panjang Scherrer; pemalar dielektrik; spektroskopi impedans

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*Pengarang untuk surat-menyurat; email: nsabirin@um.edu.my