Effect of Ag-deposited cathodes on the charging-discharging performance of zinc air batteries

• Main Authors: Chung-Yu Chiang, 江忠祐
• Other Authors: 林景崎
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/43818470762755776638

碩士 === 國立中央大學 === 機械工程學系 === 105 === This study focuses on improving air cathode efficiency with Ag-deposited metal mesh for rechargeable Zn-air batteries. By adding organic acids, its surface morphology became smooth and as zinc air batteries’ cathode, charge/discharge performance was highly enhanced as well. The thesis contains three parts. The first part is the preparation of the air cathode. The second part is the electrochemical analysis of the air cathode. The third part is the full-cell charge/discharge measurements. 　　In the first section, the silver nanoclusters were electrodeposited on the SS mesh by using three-electrode electrodeposition equipment. By adding tartaric acid or citric acid, the silver particles seemed to cover extremely well on the metal mash with higher silver deposition density. On the other hand, the scattered morphology was seen without any additives. The physical properties of the materials were characterized by Scanning Electron Microscopy (SEM) and X-ray powder diffraction (XRD). From the SEM morphology analysis results, the air cathode with the citric acid additive has the finest morphology and the most complete coating. The second part is the materials’ electrochemical analyses via Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS). The results of Cyclic Voltammetry (CV) showed that air cathode had both OER and ORR activity. With Electrochemical Impedance Spectroscopy (EIS), it was found that the air cathode of addition citric acid has the minimum values in the charge transfer resistance (Rct), which is a critical factor for enhancing batteries’ performance. The third part is the Zinc-air battery full-cell test. The air electrode with citric acid assisted exhibited excellent cycling property with 98% Coulombic efficiency even after 250 cycles.