High Discharge Rate Electrodeposited Zinc Electrode for Use in Alkaline Microbattery

• Main Authors: A. L. Nor Hairin, Raihan Othman, Mohd Hanafi Ani, Hens Saputra
• Format: Article
• Language: English
• Published: IIUM Press, International Islamic University Malaysia 2012-01-01
• Series: International Islamic University Malaysia Engineering Journal
• Online Access: http://journals.iium.edu.my/ejournal/index.php/iiumej/article/view/231

High discharge rate zinc electrode is prepared from electrodeposition process. The electrolytic bath consists of zinc chloride as the metal source and ammonium chloride as the supporting electrolyte. The concentration of the supporting electrolyte is varied from zero until 4 M, while the concentration of zinc chloride is fixed at 2 M. The aim is to produce a porous zinc coating with an enhanced and intimate interfacial area per unit volume. These characteristics shall contribute towards reduced ohmic losses, improved active material utilization, and subsequently producing high rate capacity electrochemical cell. Nitrogen physisorption at 77 K is used to measure the BET surface area and pore volume density of the zinc electrodeposits. The electrodeposited zinc electrodes are then fabricated into alkaline zinc-air microbattery measuring 1 cm2 area x ca. 305 µm thick. The use of inorganic MCM-41 membrane separator enables the fabrication of a compact cell design. The quality of the electrodeposited zinc electrodes is gauged directly from the electrochemical performance of zinc-air cell. Zinc electrodeposits prepared from electrolytic bath of 2 M NH4Cl produces the highest discharge capacity. ABSTRAK: Elektrod zink dengan kadar discas tinggi telah dihasilkan dengan proses saduran elektrokimia. Takungan elektrolit terdiri daripada zink klorida sebagai sumber logam dan ammonium klorida sebagai elektrolit sokongan. Kepekatan elektrolit sokongan diubah daripada sifar hingga 4 M, sementara kepekatan zink klorida ditetapkan pada 2 M. Ini bertujuan untuk mendapatkan saduran zink yang poros dengan luas permukaan per unit isipadu dan sentuhan antaramuka yang dipertingkatkan. Ciri-ciri ini akan menyumbang terhadap pengurangan kehilangan disebabkan kerintangan, pertambahan dalam gunapakai bahan aktif dan akhirnya menghasilkan sel elektrokimia berprestasi tinggi. Physisorpsi nitrogen pada 77 K telah digunakan untuk mengukur luas permukaan BET dan isipadu liang saduran zink. Saduran zink kemudiannya dijadikan elektrod bagi bateri mikro zink-udara beralkali dengan saiz 1 cm2 luas x ca. 305 µm tebal. Penggunaan membran tak organik MCM-41 membolehkan pembuatan sel dengan rekabentuk padat. Kualiti elektrod saduran zink telah dinilai secara lansung daraipada prestasi elektrokimia sel zink-udara. Saduran zink yang disediakan daripada takungan elektrolit 2 M NH4Cl menghasilkan kapasiti discas tertinggi. KEY WORDS (keyword)):  Zinc electrodeposition, High discharge rate electrode, MCM-41 separator, Zinc-air cell and Alkaline microbattery.