Air electrode and preparation method and application thereof

Abstract

The invention provides a preparation method of an air electrode. The preparation method comprises the following steps of 1) preparing a gas diffusion slurry from C powder, industrial alcohol and PTFEemulsion; 2) enabling the gas diffusion slurry to form a gas diffusion film at one side of a current collector; 3) preparing the catalytic slurry from the C powder, industrial alcohol, a catalyst, a pore-forming agent and PTFE emulsion, wherein the pore-forming agent is selected from any one of ammonium oxalate, ammonium bicarbonate, polyethylene glycol 200 and polyvinyl alcohol; 4) forming a catalytic membrane from the catalytic slurry at the other side of the current collector; and 5) sintering the current collector of which the two sides are respectively provided with the gas diffusion filmand the catalytic film to prepare the air electrode which has the relatively higher porosity, relatively longer electrode service life and relatively more excellent electrical property. In addition,the invention also provides the air electrode prepared by the preparation method of the air electrode and the application of the air electrode in the field of membrane electrodes.

Description

technical field [0001] The invention relates to the technical field of air electrode preparation, in particular to a method for preparing an air electrode. Background technique [0002] The air electrode is a kind of gas diffusion electrode, which has been widely studied because of its energy saving and environmental protection characteristics and its application in energy batteries. The air electrode usually includes a gas diffusion layer, a current collector, and a catalytic layer. The reaction gas enters the catalytic layer through the gas diffusion layer to undergo a gas-liquid-solid three-phase electrochemical reaction, and the electron gain and loss transfer process is completed through the current collector. In order to improve the electrode life and electrical performance of air electrodes, efforts have been made to improve the preparation methods of air electrodes. In the prior art, in the preparation process of the air electrode, the pore structure of the catalyti...

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Problems solved by technology

On the one hand, because the decomposition temperature of inorganic salt and metal powder is too high, and the preparation temperature is not enough to completely decompose it, resulting in inorganic salt and metal powder remaining in the air electrode so that the porosity of the air electrode is not high; on the other hand, due to inorganic The uneven particle size distribution of the salt and metal powder makes the pore size and distribution of the prepared air electrode different, so that the reaction gas cannot enter the catalytic layer and a good gas-liquid-solid three-phase electrochemical reaction cannot occur, hindering The diffusion of the reaction gas in the catalytic layer is aggravated, and the polarization of the air battery is aggravated, thereby reducing the electrode life and electrical performance of the air electrode.

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