| Summary: | 碩士 === 國立中正大學 === 化學工程所 === 97 === This study focused on the fabrication and characteristics analysis of the air-cathode and the zinc anode, in order to increase the performance of zinc-air battery. We used manganese oxidation nanomaterials as the catalysts, which have high activity and good chemical stability. Compare with commercial manganese dioxide, nanoscale manganese oxidations are better in its catalytic ability. Through the research of the functions of the air-cathode and the zinc anode, the efficiency and the lifetime of the battery have been increased.
The structure of the zinc-air battery can be categorized into three main parts, namely: the air-cathode, the zinc anode and the electrolyte. By finding the most active nanoscale manganese oxidation catalyst and by using material and electrochemical analyses, we have obtained the best operation conditions for the air-cathode. The influence of the contents of the binder and carbon source in the gas-diffusion layer is especially explored. This exploration prevents polarization on the surface of the electrode during high current density discharging, while promoting the rate of the electronic transmission of the air-cathode to increase the overall performance of the battery. The optimal composition for the gas-diffusion layer is 60wt% carbon nanocapsules (CNC) and 40wt% PTFE. In regard to the zinc anode, CNC with high specific surface area is added into the zinc powder to prevent passivation of the zinc anode in the electrolyte, so that the decrease in battery performance can be avoided.
On the operational level, a single zinc-air battery that is able to provide sufficient power to mobilize an electric fan has been successfully constructed. The structure of the air-cathode allows air to enter, while the other end of the air-cathode comes into contact with the electrolyte to form a solid, a liquid and a gas interface. These interfaces allow the gas to go through the process of oxygen reduction reaction. For such an exchangeable zinc-air battery, if the zinc anode should corrode or be reshaped, it can be conveniently replaced.
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